Publications

2023

42.  Drug Reprofiling to Identify Potential HIV-1 Protease Inhibitors.

Okafor SN, Meyer A, Gadsden J, Ahmed F, Guzmán L, Ahmed H, Romero JA, Angsantikul P.
Molecules. 2023;28(17):6330.

[Pubmed] [Link]

The use of protease inhibitors in human immunodeficiency virus type 1 (HIV-1) treatment is limited by adverse effects, including metabolic complications. To address these challenges, efforts are underway in the pursuit of more potent and less toxic HIV-1 protease inhibitors. Repurposing existing drugs offers a promising avenue to expedite the drug discovery process, saving both time and costs compared to conventional de novo drug development. This study screened FDA-approved and investigational drugs in the DrugBank database for their potential as HIV-1 protease inhibitors. Molecular docking studies and cell-based assays, including anti-HIV-1 in vitro assays and XTT cell viability tests, were conducted to evaluate their efficacy. The study findings revealed that CBR003PS, an antibiotic currently in clinical use, and CBR013PS, an investigational drug for treating endometriosis and uterine fibroids, exhibited significant binding affinity to the HIV-1 protease with high stability. Their EC50 values, measured at 100% cell viability, were 9.4 nM and 36.6 nM, respectively. Furthermore, cell-based assays demonstrated that these two compounds showed promising results, with therapeutic indexes higher than 32. In summary, based on their favorable therapeutic indexes, CBR003PS and CBR013PS show potential for repurposing as HIV-1 protease inhibitors.

41.  Development of Mucoadhesive Electrospun Scaffolds for Intravaginal Delivery of Lactobacilli spp., a Tenside, and Metronidazole for the Management of Bacterial Vaginosis. 

Ilomuanya MO, Bassey PO, Ogundemuren DA, Ubani-Ukoma UN, Tsamis A, Fan Y, Michalakis K, Angsantikul P, Usman A, Amenaghawon AN.
Pharmaceutics. 2023;15(4):1263.

[Pubmed] [Link]

Bacterial vaginosis (BV) is an infection of the vagina associated with thriving anaerobes, such as Gardnerella vaginitis and other associated pathogens. These pathogens form a biofilm responsible for the recurrence of infection after antibiotic therapy. The aim of this study was to develop a novel mucoadhesive polyvinyl alcohol and polycaprolactone electrospun nanofibrous scaffolds for vaginal delivery, incorporating metronidazole, a tenside, and Lactobacilli. This approach to drug delivery sought to combine an antibiotic for bacterial clearance, a tenside biofilm disruptor, and a lactic acid producer to restore healthy vaginal flora and prevent the recurrence of bacterial vaginosis. F7 and F8 had the least ductility at 29.25% and 28.39%, respectively, and this could be attributed to the clustering of particles that prevented the mobility of the crazes. F2 had the highest at 93.83% due to the addition of a surfactant that increased the affinity of the components. The scaffolds exhibited mucoadhesion between 31.54 ± 0.83% and 57.86 ± 0.95%, where an increased sodium cocoamphoacetate concentration led to increased mucoadhesion. F6 showed the highest mucoadhesion at 57.86 ± 0.95%, as compared to 42.67 ± 1.22% and 50.89 ± 1.01% for the F8 and F7 scaffolds, respectively. The release of metronidazole via a non-Fickian diffusion-release mechanism indicated both swelling and diffusion. The anomalous transport within the drug-release profile pointed to a drug-discharge mechanism that combined both diffusion and erosion. The viability studies showed a growth of Lactobacilli fermentum in both the polymer blend and the nanofiber formulation that was retained post-storage at 25 °C for 30 days. The developed electrospun scaffolds for the intravaginal delivery of Lactobacilli spp., along with a tenside and metronidazole for the management of bacterial vaginosis, provide a novel tool for the treatment and management of recurrent vaginal infection.

40.   SNAC for Enhanced Oral Bioavailability: An Updated Review.

Kommineni N, Sainaga Jyothi VG, Butreddy A, Raju S, Shapira T, Khan W, Angsantikul P, Domb AJ. Pharmaceutical Research. 2023;40(3):633-50.

[Pubmed] [Link]

The delivery of proteins and peptides via an oral route poses numerous challenges to improve the oral bioavailability and patient compliance. To overcome these challenges, as well as to improve the permeation of proteins and peptides via intestinal mucosa, several chemicals have been studied such as surfactants, fatty acids, bile salts, pH modifiers, and chelating agents, amongst these medium chain fatty acid like C10 (sodium caprate) and Sodium N-[8-(2-hydroxybenzoyl) amino] caprylate (SNAC) and its derivatives that have been well studied from a clinical perspective. This current review enumerates the challenges involved in protein and peptide delivery via the oral route, i.e., non-invasive routes of protein and peptide administration. This review also covers the chemistry behind SNAC and toxicity as well as mechanisms to enhance the oral delivery of clinically proven molecules like simaglutide and other small molecules under clinical development, as well as other permeation enhancers for efficient delivery of proteins and peptides. 

39.  Deep Eutectic Solvents for Subcutaneous Delivery of Protein Therapeutics.

Curreri AM, Kim J, Dunne M, Angsantikul P, Goetz M, Gao Y, Mitragotri S. 
Advanced Science. 2023;10(7):2205389.

[Pubmed] [Link]

Proteins are among the most common therapeutics for the treatment of diabetes, autoimmune diseases, cancer, and metabolic diseases, among others. Despite their common use, current protein therapies, most of which are injectables, have several limitations. Large proteins such as monoclonal antibodies (mAbs) suffer from poor absorption after subcutaneous injections, thus forcing their administration by intravenous injections. Even small proteins such as insulin suffer from slow pharmacokinetics which poses limitations in effective management of diabetes. Here, a deep eutectic-based delivery strategy is used to offer a generalized approach for improving protein absorption after subcutaneous injections. The lead formulation enhances absorption of mAbs after subcutaneous injections by ≈200%. The same composition also improves systemic absorption of subcutaneously injected insulin faster than Humalog, the current gold-standard of rapid acting insulin. Mechanistic studies reveal that the beneficial effect of deep eutectics on subcutaneous absorption is mediated by their ability to reduce the interactions of proteins with the subcutaneous matrix, especially collagen. Studies also confirm that these deep eutectics are safe for subcutaneous injections. Deep eutectic-based formulations described here open new possibilities for subcutaneous injections of therapeutic proteins. 

2022

38.  Discovery of novel HIV protease inhibitors using modern computational techniques.

Okafor SN, Angsantikul P, Ahmed H.
International Journal of Molecular Sciences. 2022;23(20):12149.

[Pubmed] [Link]

The human immunodeficiency virus type 1 (HIV-1) has continued to be a global concern. With the new HIV incidence, the emergence of multi-drug resistance and the untoward side effects of currently used anti-HIV drugs, there is an urgent need to discover more efficient anti-HIV drugs. Modern computational tools have played vital roles in facilitating the drug discovery process. This research focuses on a pharmacophore-based similarity search to screen 111,566,735 unique compounds in the PubChem database to discover novel HIV-1 protease inhibitors (PIs). We used an in silico approach involving a 3D-similarity search, physicochemical and ADMET evaluations, HIV protease-inhibitor prediction (IC50/percent inhibition), rigid receptor–molecular docking studies, binding free energy calculations and molecular dynamics (MD) simulations. The 10 FDA-approved HIV PIs (saquinavir, lopinavir, ritonavir, amprenavir, fosamprenavir, atazanavir, nelfinavir, darunavir, tipranavir and indinavir) were used as reference. The in silico analysis revealed that fourteen out of the twenty-eight selected optimized hit molecules were within the acceptable range of all the parameters investigated. The hit molecules demonstrated significant binding affinity to the HIV protease (PR) when compared to the reference drugs. The important amino acid residues involved in hydrogen bonding and п-п stacked interactions include ASP25, GLY27, ASP29, ASP30 and ILE50. These interactions help to stabilize the optimized hit molecules in the active binding site of the HIV-1 PR (PDB ID: 2Q5K). HPS/002 and HPS/004 have been found to be most promising in terms of IC50/percent inhibition (90.15%) of HIV-1 PR, in addition to their drug metabolism and safety profile. These hit candidates should be investigated further as possible HIV-1 PIs with improved efficacy and low toxicity through in vitro experiments and clinical trial investigations.

37. Biomimetic Targeted Theranostic Nanoparticles for Breast Cancer Treatment.

Marshall SK, Angsantikul P, Pang Z, Nasongkla N, Hussen RSD, Thamphiwatana SD. 
Molecules. 2022;27(19):6473.

[Pubmed] [Link]

The development of biomimetic drug delivery systems for biomedical applications has attracted significant research attention. As the use of cell membrane as a surface coating has shown to be a promising platform for several disease treatments. Cell-membrane-coated nanoparticles exhibit enhanced immunocompatibility and prolonged circulation time. Herein, human red blood cell (RBC) membrane-cloaked nanoparticles with enhanced targeting functionality were designed as a targeted nanotheranostic against cancer. Naturally, derived human RBC membrane modified with targeting ligands coated onto polymeric nanoparticle cores containing both chemotherapy and imaging agent. Using epithelial cell adhesion molecule (EpCAM)-positive MCF-7 breast cancer cells as a disease model, the nature-inspired targeted theranostic human red blood cell membrane-coated polymeric nanoparticles (TT-RBC-NPs) platform was capable of not only specifically binding to targeted cancer cells, effectively delivering doxorubicin (DOX), but also visualizing the targeted cancer cells. The TT-RBC-NPs achieved an extended-release profile, with the majority of the drug release occurring within 5 days. The TT-RBC-NPs enabled enhanced cytotoxic efficacy against EpCAM positive MCF-7 breast cancer over the non-targeted NPs. Additionally, fluorescence images of the targeted cancer cells incubated with the TT-RBC-NPs visually indicated the increased cellular uptake of TT-RBC-NPs inside the breast cancer cells. Taken together, this TT-RBC-NP platform sets the foundation for the next-generation stealth theranostic platforms for systemic cargo delivery for treatment and diagnostic of cancer.

36. Freeze-drying for the preservation of immunoengineering products

Kommineni N, Butreddy A, Jyothi VG, Angsantikul P.
Iscience. 2022;25(10):105127.

[Pubmed] [Link]

Immunoengineering technologies harness the power of immune system modulators such as monoclonal antibodies, cytokines, and vaccines to treat myriad diseases. Immunoengineering innovations have showed great promise in various practices including oncology, infectious disease, autoimmune diseases, and transplantation. Despite the countless successes, the majority of immunoengineering products contain active moieties that are prone to instability. The current review aims to feature freeze-drying as a robust and scalable solution to the inherent stability challenges in immunoengineering products by preventing the active moiety from degradation. Furthermore, this review describes the stability issues related to immunoengineering products and the utility of the lyophilization process to preserve the integrity and efficacy of immunoengineering tools ranging from biologics to nanoparticle-based vaccines. The concept of the freeze-drying process is described highlighting the quality by design (QbD) for robust process optimization. Case studies of lyophilized immunoengineering technologies and relevant clinical studies using immunoengineering products are discussed.

2021

35. Ionic Liquids and Deep Eutectic Solvents for Enhanced Delivery of Antibodies in the Gastrointestinal Tract

Angsantikul P, Peng K, Curreri AM, Chua Y, Chen KZ, Ehondor J, Mitragotri S.
Advanced Functional Materials. 2021;31(44):2002912.

[Link]

Monoclonal antibodies (mAbs) are currently used for the treatment of numerous conditions including cancer, psoriasis, arthritis, and atopic dermatitis, among others. All mAbs are currently administered by either intravenous or subcutaneous injections. Herein, the use of a novel ionic liquid and deep eutectic solvent, choline and glycolate (CGLY), as a platform for gastrointestinal administration of therapeutic antibodies is reported. CGLY maintains the stability and structure of TNFα antibody. CGLY significantly enhances paracellular transport of TNFα antibody in vitro. CGLY also reduces the viscosity of the intestinal mucus, another key barrier for antibody transport. In vivo results in rats demonstrate that CGLY effectively delivers TNFα antibody into the intestinal mucosa as well as systemic circulation. One week repeat dose study followed by histology and serum biochemistry analysis indicates that CGLY is well tolerated by rats. Overall, this work illustrates the promise of using choline-based ionic liquids and deep eutectic solvents as an oral delivery platform for local as well as systemic delivery of therapeutic antibodies.

34. Modulation of gastrointestinal mucus properties with ionic liquids for drug delivery

Peng K, Gao Y, Angsantikul P, LaBarbiera A, Goetz M, Curreri AM, Rodrigues D, Tanner EE, Mitragotri S.
Advanced Healthcare Materials. 2021;10(13):2002192.  

[Pubmed] [Link]

The mucus barrier lining the gastrointestinal tract poses a significant barrier to the oral delivery of macromolecular drugs. Successful approaches to overcoming this barrier have primarily focused on reducing drug and carrier interactions with mucus or disrupting the mucus layer directly. Choline-based ionic liquids (ILs) such as choline geranate and choline glycolate (CGLY) have recently been shown to be effective in enhancing the intestinal absorption of macromolecules such as insulin and immunoglobulin (IgG), respectively. Herein, the use of choline-based ILs as mucus-modulating agents for safely improving drug penetration through mucus is described. Choline-based ILs significantly increase the diffusion rates of cationic dextrans through mucin solution. Choline-maleic acid (CMLC 2:1) enhances the diffusion of 4 kDa cationic dextran in mucin solution by more than fourfold when compared to phosphate-buffered saline control. Choline-based ILs also reduce mucus viscosity without significantly impacting the native mucus gel structure. In vitro studies in a mucus-secreting coculture model with Caco-2 and HT29MTX-E12 cells further demonstrate the effectiveness of ILs in improving transport of cationic molecules in the presence of secreted mucus. This work demonstrates the potential for choline-based ionic liquids to be used as nondestructive mucus-modulating agents for enabling enhanced oral delivery of macromolecular drug.

2020

33. Ionic‐Liquid‐Based Safe Adjuvants

Ukidve A, Cu K, Goetz M, Angsantikul P, Curreri A, Tanner EEL, Mitragotri S.
Advanced Materials. 2020;32(46):e2002990.

[Pubmed] [Link]

Adjuvants play a critical role in the design and development of novel vaccines. Despite extensive research, only a handful of vaccine adjuvants have been approved for human use. Currently used adjuvants are mostly composed of components that are non‐native to the human body, such as aluminum salt, bacterial lipids, or foreign genomic material. Here, a new ionic‐liquid‐based adjuvant is explored, synthesized using two metabolites of the body, choline and lactic acid (ChoLa). ChoLa distributes the antigen efficiently upon injection, maintains antigen integrity, enhances immune infiltration at the injection site, and leads to a potent immune response against the antigen. Thus, it can serve as a promising safe adjuvant platform that can help to protect against pandemics and future infectious threats.

32. Amphiphilic polyacrylamide excipients lead to a record-breaking fast-acting insulin

Angsantikul P, Mitragotri S.
Trends in Pharmacological Sciences. 2020;41(10):681-4.

[Pubmed] [Link]

Fast-acting insulins are central to the regulation of prandial glucose in diabetic patients. Current fast-acting insulins require 20–30 min for the onset and longer for the peak blood concentrations. The recent work by Mann et al. used high-throughput synthesis and screening of polyacrylamide-based excipients to yield a formulation with pharmacokinetics that is faster than the currently available fast-acting insulins.

31. Ionic Liquids and Deep Eutectic Solvents for Enhanced Delivery of Antibodies in the Gastrointestinal Tract

Angsantikul P, Peng K, Curreri AM, Chua Y, Chen KZ, Ehondor J, Mitragotri S.
Advanced Functional Materials. 2020:e2002912.

[Link]

Monoclonal antibodies (mAbs) are currently used for the treatment of numerous conditions including cancer, psoriasis, arthritis, and atopic dermatitis, among others. All mAbs are currently administered by either intravenous or subcutaneous injections. Herein, the use of a novel ionic liquid and deep eutectic solvent, choline and glycolate (CGLY), as a platform for gastrointestinal administration of therapeutic antibodies is reported. CGLY maintains the stability and structure of TNFα antibody. CGLY significantly enhances paracellular transport of TNFα antibody in vitro. CGLY also reduces the viscosity of the intestinal mucus, another key barrier for antibody transport. In vivo results in rats demonstrate that CGLY effectively delivers TNFα antibody into the intestinal mucosa as well as systemic circulation. One week repeat dose study followed by histology and serum biochemistry analysis indicates that CGLY is well tolerated by rats. Overall, this work illustrates the promise of using choline‐based ionic liquids and deep eutectic solvents as an oral delivery platform for local as well as systemic delivery of therapeutic antibodies..

2019

30. Composite thermoresponsive hydrogel with auranofin-loaded nanoparticles for topical treatment of vaginal trichomonad infection

Zhang Y, Miyamoto Y, Ihara S, Yang JZ, Zuill DE, Angsantikul P, Zhang A, Gao W, Zhang L, Eckmann L. 
Advanced Therapeutics. 2019;2(12).

[Pubmed] [Link]

Trichomonas vaginalis is responsible for the most common non‐viral sexually transmitted disease worldwide. Standard treatment is with oral metronidazole or tinidazole, but resistance is emerging and adverse effects can be problematic. Topical treatment offers potential benefits for increasing local drug concentrations while reducing systemic exposure, but none are currently approved for trichomoniasis. The anti‐rheumatic drug, auranofin (AF), was recently discovered to have significant trichomonacidal activity, but has a long plasma half‐life and significant adverse effects. Here, this drug is used as a model to develop a novel topical formulation composed of AF‐loaded nanoparticles (NP) embedded in a thermoresponsive hydrogel for intravaginal administration. The AF‐NP composite gel shows sustained drug release for at least 12 h, and underwent sol–gel transition with increased viscoelasticity within a minute. Intravaginal administration in mice shows excellent NP retention for >6 h and markedly increases local AF levels, but reduces plasma and liver levels compared to oral treatment with a much higher dose. Furthermore, intravaginal AF‐NP gel greatly outperforms oral AF in eliminating vaginal trichomonad infection in mice, while causing no systemic or local toxicity. These results show the potential of the AF‐NP hydrogel formulation for effective topical therapy of vaginal infections.

29. Inhibition of Pathogen Adhesion by Bacterial Outer Membrane-Coated Nanoparticles

Zhang Y, Chen Y, Lo C, Zhuang J, Angsantikul P, Zhang Q, Wei Z, Zhou Z, Obonyo M, Fang RH, Gao W, Zhang L.
Angewandte Chemie International Edition. 2019;58(33):11404-8.

[Pubmed] [Link]

Anti-adhesion therapies interfere with the bacterial adhesion to the host and thus avoid direct disruption of bacterial cycles for killing, which may alleviate resistance development. Herein, an anti-adhesion nanomedicine platform is made by wrapping synthetic polymeric cores with bacterial outer membranes. The resulting bacterium-mimicking nanoparticles (denoted “OM-NPs”) compete with source bacteria for binding to the host. The “top-down” fabrication of OM-NPs avoids the identification of the adhesins and bypasses the design of agonists targeting these adhesins. In this study, OM-NPs are made with the membrane of Helicobacter pylori and shown to bind with gastric epithelial cells (AGS cells). Treatment of AGS cells with OM-NPs reduces H. pylori adhesion and such anti-adhesion efficacy is dependent on OM-NP concentration and its dosing sequence.

28. Biomimetic Micromotor Enables Active Delivery of Antigens for Oral Vaccination. 

Wei X, Beltran-Gastelum M, Karshalev E, Esteban-Fernandez de Avila B, Zhou J, Ran D, Angsantikul P, Fang RH, Zang J, Zhang L.
Nano Letters. 2019;19(3):1914-21.

[Pubmed] [Link]

Vaccination represents one of the most effective means of preventing infectious disease. In order to maximize the utility of vaccines, highly potent formulations that are easy to administer and promote high patient compliance are desired. In the present work, a biomimetic self-propelling micromotor formulation is developed for use as an oral antivirulence vaccine. The propulsion is provided by a magnesium-based core, and a biomimetic cell membrane coating is used to detain and neutralize a toxic antigenic payload. The resulting motor toxoids leverage their propulsion properties in order to more effectively elicit mucosal immune responses. After demonstrating the successful fabrication of the motor toxoids, their uptake properties are shown in vitro. When delivered to mice via an oral route, it is then confirmed that the propulsion greatly improves retention and uptake of the antigenic material in the small intestine in vivo. Ultimately, this translates into markedly elevated generation of antibody titers against a model toxin. This work provides a proof-of-concept highlighting the benefits of active oral delivery for vaccine development, opening the door for a new set of applications, in which biomimetic motor technology can provide significant benefits.

27. Parallel Label‐Free Isolation of Cancer Cells Using Arrays of Acoustic Microstreaming Traps

Lu X, Martin A, Angsantikul P, Li J, Soto F, Chen C, Liang Y, Hu J, Zhang L, Wang J. 
Advanced Materials Technologies. 2019;4(2):1800374

[Link]

A new parallel label‐free isolation platform for isolating cancer cells (>10 µm) from biological samples using an array of acoustic microstreaming traps is demonstrated. The new microstreaming trapping platform offers high isolation efficiency and treatment in spiked diluted (1:2) blood samples without labeling, extra processing steps or sheath flows (common to other label‐free cell‐separation methods), hence, simplifying the microfluidic set‐up and operation. The versatility of this label‐free method is illustrated by the size‐dependent isolation of synthetic colloids and by three different models of breast cancer cells, showing a remarkably high isolation efficiency (95 ± 5%), being ≈100% for MCF‐7. Extensive experimental data and theoretical simulations confirm that the local acoustic microstreaming produced by the micropillar trap can discriminate and isolate microparticles based solely on their size. Moreover, the parallel isolation generated by the trap array arrangement is capable of effectively improving the capturing efficiency. The tunable and reversible properties of the acoustic microstreaming allow for cell capturing and optical detection within the trapping area, followed by cell release, enrichment, and collection for further studies. This label‐free trapping strategy can open numerous new opportunities for rapid and sensitive detection and capture of cancer cells in biological samples for meaningful clinical applications.

2018

26. Micromotor Pills as a Dynamic Oral Delivery Platform 

Karshalev E, Esteban-Fernandez de Avila B, Beltran-Gastelum M, Angsantikul P, Tang S, Mundaca-Uribe R, Zhang F, Zhao J, Zhang L, Wang J. 
ACS Nano. 2018;12(8):8397-405.

[Pubmed] [Link]

Tremendous progress has been made during the past decade toward the design of nano/micromotors with high biocompatibility, multifunctionality, and efficient propulsion in biological fluids, which collectively have led to the initial investigation of in vivo biomedical applications of these synthetic motors. Despite these recent advances in micromotor designs and mechanistic research, significant effort is needed to develop appropriate formulations of micromotors to facilitate their in vivo administration and thus to better test their in vivo applicability. Herein, we present a micromotor pill and demonstrate its attractive use as a platform for in vivo oral delivery of active micromotors. The micromotor pill is comprised of active Mg-based micromotors dispersed uniformly in the pill matrix, containing inactive (lactose/maltose) excipients and other disintegration-aiding (cellulose/starch) additives. Our in vivo studies using a mouse model show that the micromotor pill platform effectively protects and carries the active micromotors to the stomach, enabling their release in a concentrated manner. The micromotor encapsulation and the inactive excipient materials have no effects on the motion of the released micromotors. The released cargo-loaded micromotors propel in gastric fluid, retaining the high-performance characteristics of in vitro micromotors while providing higher cargo retention onto the stomach lining compared to orally administrated free micromotors and passive microparticles. Furthermore, the micromotor pills and the loaded micromotors retain the same characteristics and propulsion behavior after extended storage in harsh conditions. These results illustrate that combining the advantages of traditional pills with the efficient movement of micromotors offer an appealing route for administrating micromotors for potential in vivo biomedical applications.

25. Coating nanoparticles with gastric epithelial cell membrane for targeted antibiotic delivery against Helicobacter pylori infection

Angsantikul P, Thamphiwatana S, Zhang Q, Spiekermann K, Zhuang J, Fang RH, Gao W, Obonyo M, Zhang L.
Advanced Therapeutics. 2018;1(2):1800016.

[Pubmed] [Link]

Inspired by the natural pathogen–host interactions and adhesion, this study reports on the development of a novel targeted nanotherapeutic for the treatment of Helicobacter pylori infection. Specifically, plasma membranes of gastric epithelial cells (e.g., AGS cells) are collected and coated onto antibiotic‐loaded polymeric cores; the resulting biomimetic nanoparticles (denoted AGS‐NPs) bear the same surface antigens as the source AGS cells and thus have inherent adhesion to H. pylori bacteria. When incubated with H. pylori bacteria in vitro, the AGS‐NPs preferentially accumulate on the bacterial surfaces. Using clarithromycin (CLR) as a model antibiotic and a mouse model of H. pylori infection, the CLR‐loaded AGS‐NPs demonstrate superior therapeutic efficacy when compared with the free drug counterpart as well as a non‐targeted nanoparticle control group. Overall, this work illustrates the promise and strength of using natural host cell membranes to functionalize drug nanocarriers for targeted drug delivery to pathogens that colonize on the host cells. As host–pathogen adhesion represents a common biological event for various types of pathogenic bacteria, the bioinspired nanotherapeutic strategy reported here represents a versatile delivery platform that may be applied to treat numerous infectious diseases.

24. Micromotors Go In Vivo From Test Tubes to Live Animals

Esteban-Fernandez de Avila B, Angsantikul P, Li J, Gao W, Zhang L, Wang J.
Advanced Functional Materials. 2018;28(25):1705640.

[Link]

While synthetic micromotors have been evaluated extensively under in vitro conditions for over a decade, their in vivo function has rarely been explored. Recent research effort has resulted in micromotors that display fast movement in complex biological media, and possess efficient cargo loading, transport, and release, along with good biocompatibility. These new capabilities have made synthetic micromotors promising active delivery tools for in vivo applications including treatment of enteral diseases. This review highlights several examples of recent in vivo applications using different types of biocompatible and biodegradable chemically powered body‐fuel‐propelled micromotors, including precise micromotor tissue localization and retention, autonomous gastric fluid neutralization and cargo release, and enhanced drug delivery toward enhanced treatment of stomach bacterial infection. Zn and Mg‐based micromotors, powered by body fluids, have shown unique advantages to operate at different regions of the gastrointestinal tract. This review also covers some early in vitro studies that paved the way for the current in vivo applications, along with future prospects and challenges.

23. Hybrid biomembrane-functionalized nanorobots for concurrent removal of pathogenic bacteria and toxins

Esteban-Fernandez de Avila B, Angsantikul P, Ramirez-Herrera DE, Soto F, Teymourian H, Dehaini D, Chen Y, Zhang L, Wang J.
Science Robotics. 2018;3(18):eaat0485.

[Pubmed] [Link]

With the rapid advancement of robotic research, it becomes increasingly interesting and important to develop biomimetic micro- or nanorobots that translate biological principles into robotic systems. We report the design, construction, and evaluation of a dual–cell membrane–functionalized nanorobot for multipurpose removal of biological threat agents, particularly concurrent targeting and neutralization of pathogenic bacteria and toxins. Specifically, we demonstrated ultrasound-propelled biomimetic nanorobots consisting of gold nanowires cloaked with a hybrid of red blood cell (RBC) membranes and platelet (PL) membranes. Such hybrid cell membranes have a variety of functional proteins associated with human RBCs and PLs, which give the nanorobots a number of attractive biological capabilities, including adhesion and binding to PL-adhering pathogens (e.g., Staphylococcus aureus bacteria) and neutralization of pore-forming toxins (e.g., α-toxin). In addition, the biomimetic nanorobots displayed rapid and efficient prolonged acoustic propulsion in whole blood, with no apparent biofouling, and mimicked the movement of natural motile cells. This propulsion enhanced the binding and detoxification efficiency of the robots against pathogens and toxins. Overall, coupling these diverse biological functions of hybrid cell membranes with the fuel-free propulsion of the nanorobots resulted in a dynamic robotic system for efficient isolation and simultaneous removal of different biological threats, an important step toward the creation of a broad-spectrum detoxification robotic platform.

22. Active Intracellular Delivery of a Cas9/sgRNA Complex Using Ultrasound-Propelled Nanomotors

Hansen-Bruhn M, de Avila BE, Beltran-Gastelum M, Zhao J, Ramirez-Herrera DE, Angsantikul P, Vesterager Gothelf K, Zhang L, Wang J.
Angewandte Chemie International Edition. 2018;57(10):2657-61.

[Pubmed] [Link]

Direct and rapid intracellular delivery of a functional Cas9/sgRNA complex using ultrasound-powered nanomotors is reported. The Cas9/sgRNA complex is loaded onto the nanomotor surface through a reversible disulfide linkage. A 5 min ultrasound treatment enables the Cas9/sgRNA-loaded nanomotors to directly penetrate through the plasma membrane of GFP-expressing B16F10 cells. The Cas9/sgRNA is released inside the cells to achieve highly effective GFP gene knockout. The acoustic Cas9/sgRNA-loaded nanomotors display more than 80 % GFP knockout within 2 h of cell incubation compared to 30 % knockout using static nanowires. More impressively, the nanomotors enable highly efficient knockout with just 0.6 nm of the Cas9/sgRNA complex. This nanomotor-based intracellular delivery method thus offers an attractive route to overcome physiological barriers for intracellular delivery of functional proteins and RNAs, thus indicating considerable promise for highly efficient therapeutic applications.

21. Neutralization of cholera toxin with nanoparticle decoys for treatment of cholera 

Das S, Angsantikul P, Le C, Bao D, Miyamoto Y, Gao W, Zhang L, Eckmann L.
PLOS Neglected Tropical Diseases. 2018;12(2):e0006266.

[Pubmed] [Link]

Diarrheal diseases are a major cause of morbidity and mortality worldwide. In many cases, antibiotic therapy is either ineffective or not recommended due to concerns about emergence of resistance. The pathogenesis of several of the most prevalent infections, including cholera and enteroxigenic Escherichia coli, is dominated by enterotoxins produced by lumen-dwelling pathogens before clearance by intestinal defenses. Toxins gain access to the host through critical host receptors, making these receptors attractive targets for alternative antimicrobial strategies that do not rely on conventional antibiotics. Here, we developed a new nanotechnology strategy as a countermeasure against cholera, one of the most important and prevalent toxin-mediated enteric infections. The key host receptor for cholera toxin, monosialotetrahexosylganglioside (GM1), was coated onto the surface of polymeric nanoparticles. The resulting GM1-polymer hybrid nanoparticles were shown to function as toxin decoys by selectively and stably binding cholera toxin, and neutralizing its actions on epithelial cells in vitro and in vivo. Furthermore, the GM1-coated nanoparticle decoys attenuated epithelial 3′,5′-cyclic adenosine monophosphate production and fluid responses to infection with live Vibrio cholera in cell culture and a murine infection model. Together, these studies illustrate that the new nanotechnology-based platform can be employed as a non-traditional antimicrobial strategy for the management of enteric infections with enterotoxin-producing pathogens.

20. Chemotactic Guidance of Synthetic Organic/Inorganic Payloads Functionalized Sperm Micromotors

Chen C, Chang X, Angsantikul P, Li J, Esteban-Fernandez de Avila B, Karshalev E, Liu W, Mou F, He S, Castillo R, Liang Y, Guan J, Zhang L, Wang J.
Advanced Biosystems. 2018;2(1):1700160

[Link]

The preparation and operation of free swimming functionalized sperm micromotors (FSFSMs) as intelligent self‐guided biomotors with intrinsic chemotactic motile behavior are reported. The natural sperm biomotors are functionalized with a wide variety of synthetic nanoscale payloads, such as CdSe/ZnS quantum dots, doxorubicin hydrochloride drug coated iron‐oxide nanoparticles, and fluorescein isothiocyanate‐modified Pt nanoparticles via endocytosis. The FSFSMs display efficient self‐propulsion in various biological and environmental media with controllable swarming behavior upon exposure to a chemical attractant. As a new class of environmentally responsive smart biomotors, the control of the FSFSM speed is achieved by varying the solution osmolarity that leads to different flagellar lengths. High drug loading capacity and responsive release kinetics are obtained with such sperm biomotors. The transport of synthetic cargo can be guided by the intrinsic chemotaxis of the FSFSMs. The chemotactic characteristics, speed control mechanism, and responsive payload release of the FSFSMs are investigated. Such use of free swimming functionalized sperm cells as intelligent microscale biomotors offers considerable potential for diverse biomedical and environmental applications.

19. Biomimetic Platelet-Camouflaged Nanorobots for Binding and Isolation of Biological Threats

Li J, Angsantikul P, Liu W, Esteban-Fernandez de Avila B, Chang X, Sandraz E, Liang Y, Zhu S, Zhang Y, Chen C, Gao W, Zhang L, Wang J.
Advanced Materials. 2018;30(2):1704800.

[Pubmed] [Link]

One emerging and exciting topic in robotics research is the design of micro-/nanoscale robots for biomedical operations. Unlike industrial robots that are developed primarily to automate routine and dangerous tasks, biomedical nanorobots are designed for complex, physiologically relevant environments, and tasks that involve unanticipated biological events. Here, a biologically interfaced nanorobot is reported, made of magnetic helical nanomotors cloaked with the plasma membrane of human platelets. The resulting biomimetic nanorobots possess a biological membrane coating consisting of diverse functional proteins associated with human platelets. Compared to uncoated nanomotors which experience severe biofouling effects and hence hindered propulsion in whole blood, the platelet-membrane-cloaked nanomotors disguise as human platelets and display efficient propulsion in blood over long time periods. The biointerfaced nanorobots display platelet-mimicking properties, including adhesion and binding to toxins and platelet-adhering pathogens, such as Shiga toxin and Staphylococcus aureus bacteria. The locomotion capacity and platelet-mimicking biological function of the biomimetic nanomotors offer efficient binding and isolation of these biological threats. The dynamic biointerfacing platform enabled by platelet-membrane cloaked nanorobots thus holds considerable promise for diverse biomedical and biodefense applications.

2017

18. Toxoid Vaccination against Bacterial Infection Using Cell Membrane-Coated Nanoparticles

Angsantikul P, Fang RH, Zhang L. 
Bioconjugate Chemistry. 2018;29(3):604-12.

[Pubmed] [Link]

As nanoparticles exhibit unique properties attractive for vaccine development, they have been progressively implemented as antigen delivery platforms and immune potentiators. Recently, cell membrane-coated nanoparticles have provided a novel approach for intercepting and neutralizing bacterial toxins by leveraging their natural affinity to cellular membranes. Such toxin-nanoparticle assemblies, termed nanotoxoids, allow rapid loading of different types of toxins and have been investigated for their ability to effectively confer protection against bacterial infection. This topical review will cover the current progress in antibacterial vaccine nanoformulations and highlight the nanotoxoid platform as a novel class of nanoparticulate vaccine. We aim to provide insights into the potential of nanotoxoids as a platform that is facile to implement and can be broadly applied to help address the rising threat of super pathogens.

17. Remote Loading of Small‐Molecule Therapeutics into Cholesterol‐Enriched Cell‐Membrane‐Derived Vesicles

Zhang X, Angsantikul P, Ying M, Zhuang J, Zhang Q, Wei X, Jiang Y, Zhang Y, Dehaini D, Chen M, Chen Y, Gao W, Fang RH, Zhang L.
Angewandte Chemie International Edition. 2017;56(45):14075-9.

[Pubmed] [Link]

The increasing popularity of biomimetic design principles in nanomedicine has led to therapeutic platforms with enhanced performance and biocompatibility. This includes the use of naturally derived cell membranes, which can bestow nanocarriers with cell-specific functionalities. Herein, we report on a strategy enabling efficient encapsulation of drugs via remote loading into membrane vesicles derived from red blood cells. This is accomplished by supplementing the membrane with additional cholesterol, stabilizing the nanostructure and facilitating the retention of a pH gradient. We demonstrate the loading of two model drugs: the chemotherapeutic doxorubicin and the antibiotic vancomycin. The therapeutic implications of these natural, remote-loaded nanoformulations are studied both in vitro and in vivo using animal disease models. Ultimately, this approach could be used to design new biomimetic nanoformulations with higher efficacy and improved safety profiles.

16. Macrophage-like nanoparticles concurrently absorbing endotoxins and proinflammatory cytokines for sepsis management

Thamphiwatana S, Angsantikul P, Escajadillo T, Zhang Q, Olson J, Luk BT, Zhang S, Fang RH, Gao W, Nizet V, Zhang L.
Proceedings of the National Academy of Sciences. 2017;114(43):11488-93.

[Pubmed] [Link]

Sepsis, resulting from uncontrolled inflammatory responses to bacterial infections, continues to cause high morbidity and mortality worldwide. Currently, effective sepsis treatments are lacking in the clinic, and care remains primarily supportive. Here we report the development of macrophage biomimetic nanoparticles for the management of sepsis. The nanoparticles, made by wrapping polymeric cores with cell membrane derived from macrophages, possess an antigenic exterior the same as the source cells. By acting as macrophage decoys, these nanoparticles bind and neutralize endotoxins that would otherwise trigger immune activation. In addition, these macrophage-like nanoparticles sequester proinflammatory cytokines and inhibit their ability to potentiate the sepsis cascade. In a mouse Escherichia coli bacteremia model, treatment with macrophage mimicking nanoparticles, termed MΦ-NPs, reduced proinflammatory cytokine levels, inhibited bacterial dissemination, and ultimately conferred a significant survival advantage to infected mice. Employing MΦ-NPs as a biomimetic detoxification strategy shows promise for improving patient outcomes, potentially shifting the current paradigm of sepsis management.

15. Erythrocyte membrane-coated nanogel for combinatorial antivirulence and responsive antimicrobial delivery against Staphylococcus aureus infection

Zhang Y, Zhang J, Chen W, Angsantikul P, Spiekermann KA, Fang RH, Gao W, Zhang L.
Journal of Controlled Release. 2017;263:185-91.

[Pubmed] [Link]

We reported an erythrocyte membrane-coated nanogel (RBC-nanogel) system with combinatorial antivirulence and responsive antibiotic delivery for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infection. RBC membrane was coated onto the nanogel via a membrane vesicle templated in situ gelation process, whereas the redox-responsiveness was achieved by using a disulfide bond-based crosslinker. We demonstrated that the RBC-nanogels effectively neutralized MRSA-associated toxins in extracellular environment and the toxin neutralization in turn promoted bacterial uptake by macrophages. In intracellular reducing environment, the RBC-nanogels showed an accelerated drug release profile, which resulted in more effective bacterial inhibition. When added to the macrophages infected with intracellular MRSA bacteria, the RBC-nanogels significantly inhibited bacterial growth compared to free antibiotics and non-responsive nanogel counterparts. These results indicate the great potential of the RBC-nanogel system as a new and effective antimicrobial agent against MRSA infection.

14. In Situ Capture of Bacterial Toxins for Antivirulence Vaccination

Wei X, Gao J, Wang F, Ying M, Angsantikul P, Kroll AV, Zhou J, Gao W, Lu W, Fang RH, Zhang L.
Advanced Materials. 2017;29(33).

[Pubmed] [Link]

Antivirulence vaccination is a promising strategy for addressing bacterial infection that focuses on removing the harmful toxins produced by bacteria. However, a major challenge for creating vaccines against biological toxins is that the vaccine potency is often limited by lack of antigenic breadth, as most formulations have focused on single antigens, while most bacteria secrete a plethora of toxins. Here, a facile approach for generating multiantigenic nanotoxoids for use as vaccines against pathogenic bacteria by leveraging the natural affinity of virulence factors for cellular membranes is reported. Specifically, multiple virulent toxins from bacterial protein secretions are concurrently and naturally entrapped using a membrane-coated nanosponge construct. The resulting multivalent nanotoxoids are capable of delivering virulence factors together, are safe both in vitro and in vivo, and can elicit functional immunity capable of combating live bacterial infections in a mouse model. Despite containing the same bacterial antigens, the reported nanotoxoid formulation consistently outperforms a denatured protein preparation in all of the metrics studied, which underscores the utility of biomimetic nanoparticle-based neutralization and delivery. Overall this strategy helps to address major hurdles in the design of antivirulence vaccines, enabling increased antigenic breadth while maintaining safety

13. Micromotor-enabled active drug delivery for in vivo treatment of stomach infection.

Esteban-Fernandez de Avila BE, Angsantikul P, Li J, Angel Lopez-Ramirez M, Ramirez-Herrera DE, Thamphiwatana S, Chen C, Delezuk J, Samakapiruk R, Ramez V, Obonyo M, Zhang L, Wang J.
Nature Communications. 2017;8(1):272.

[Pubmed] [Link]

Advances in bioinspired design principles and nanomaterials have led to tremendous progress in autonomously moving synthetic nano/micromotors with diverse functionalities in different environments. However, a significant gap remains in moving nano/micromotors from test tubes to living organisms for treating diseases with high efficacy. Here we present the first, to our knowledge, in vivo therapeutic micromotors application for active drug delivery to treat gastric bacterial infection in a mouse model using clarithromycin as a model antibiotic and Helicobacter pylori infection as a model disease. The propulsion of drug-loaded magnesium micromotors in gastric media enables effective antibiotic delivery, leading to significant bacteria burden reduction in the mouse stomach compared with passive drug carriers, with no apparent toxicity. Moreover, while the drug-loaded micromotors reach similar therapeutic efficacy as the positive control of free drug plus proton pump inhibitor, the micromotors can function without proton pump inhibitors because of their built-in proton depletion function associated with their locomotion.

12. Nanomotor-Enabled pH-Responsive Intracellular Delivery of Caspase-3: Toward Rapid Cell Apoptosis. 

Esteban-Fernandez de Avila B, Ramirez-Herrera DE, Campuzano S, Angsantikul P, Zhang L, Wang J.
ACS Nano. 2017;11(6):5367-74.

[Pubmed] [Link]

Direct and efficient intracellular delivery of enzymes to cytosol holds tremendous therapeutic potential while remaining an unmet technical challenge. Herein, an ultrasound (US)-propelled nanomotor approach and a high-pH-responsive delivery strategy are reported to overcome this challenge using caspase-3 (CASP-3) as a model enzyme. Consisting of a gold nanowire (AuNW) motor with a pH-responsive polymer coating, in which the CASP-3 is loaded, the resulting nanomotor protects the enzyme from release and deactivation prior to reaching an intracellular environment. However, upon entering a cell and exposure to the higher intracellular pH, the polymer coating is dissolved, thereby directly releasing the active CASP-3 enzyme to the cytosol and causing rapid cell apoptosis. In vitro studies using gastric cancer cells as a model cell line demonstrate that such a motion-based active delivery approach leads to remarkably high apoptosis efficiency within a significantly shorter time and with a lower amount of CASP-3 compared to other control groups not involving US-propelled nanomotors. For instance, the reported nanomotor system can achieve 80% apoptosis of human gastric adenocarcinoma cells within only 5 min, which dramatically outperforms other CASP-3 delivery approaches. These results indicate that the US-propelled nanomotors may act as a powerful vehicle for cytosolic delivery of active therapeutic proteins, which would offer an attractive means to enhance the current landscape of intracellular protein delivery and therapy. While CASP-3 is selected as a model protein in this study, the same nanomotor approach can be readily applied to a variety of different therapeutic proteins.

11. Nanofibre optic force transducers with sub-piconewton resolution via near-field plasmon-dielectric interactions. 

Huang Q, Lee J, Arce FT, Yoon I, Angsantikul P, Liu J, Shi Y, Villanueva J, Thamphiwatana S, Ma X, Zhang L, Chen S, Lal R, Sirbuly DJ.
Nature Photonics. 2017;11:352-5.

[Pubmed] [Link]

Ultrasensitive nanomechanical instruments, including the atomic force microscope (AFM) and optical and magnetic tweezers, have helped shed new light on the complex mechanical environments of biological processes. However, it is difficult to scale down the size of these instruments due to their feedback mechanisms, which, if overcome, would enable high-density nanomechanical probing inside materials. A variety of molecular force probes including mechanophores, quantum dots, fluorescent pairs and molecular rotors have been designed to measure intracellular stresses; however, fluorescence-based techniques can have short operating times due to photo-instability and it is still challenging to quantify the forces with high spatial and mechanical resolution. Here, we develop a compact nanofibre optic force transducer (NOFT) that utilizes strong near-field plasmon-dielectric interactions to measure local forces with a sensitivity of <200 fN. The NOFT system is tested by monitoring bacterial motion and heart-cell beating as well as detecting infrasound power in solution.

10. Erythrocyte–platelet hybrid membrane coating for enhanced nanoparticle functionalization

Dehaini D, Wei X, Fang RH, Masson S, Angsantikul P, Luk BT, Zhang Y, Ying M, Jiang Y, Kroll AV, Gao W, Zhang, L.
Advanced Materials. 2017;29(16).

[Pubmed] [Link]

Cell‐membrane‐coated nanoparticles have recently been studied extensively for their biological compatibility, retention of cellular properties, and adaptability to a variety of therapeutic and imaging applications. This class of nanoparticles, which has been fabricated with a variety of cell membrane coatings, including those derived from red blood cells (RBCs), platelets, white blood cells, cancer cells, and bacteria, exhibit properties that are characteristic of the source cell. In this study, a new type of biological coating is created by fusing membrane material from two different cells, providing a facile method for further enhancing nanoparticle functionality. As a proof of concept, the development of dual‐membrane‐coated nanoparticles from the fused RBC membrane and platelet membrane is demonstrated. The resulting particles, termed RBC–platelet hybrid membrane‐coated nanoparticles ([RBC‐P]NPs), are thoroughly characterized, and it is shown that they carry properties of both source cells. Further, the [RBC‐P]NP platform exhibits long circulation and suitability for further in vivo exploration. The reported strategy opens the door for the creation of biocompatible, custom‐tailored biomimetic nanoparticles with varying hybrid functionalities, which may be used to overcome the limitations of current nanoparticle‐based therapeutic and imaging platforms.

9. Micromotors Spontaneously Neutralize Gastric Acid for pH-Responsive Payload Release

Li J, Angsantikul P, Liu W, Esteban-Fernandez de Avila B, Thamphiwatana S, Xu M, Sandraz E, Wang X, Delezuk J, Gao W, Zhang L, Wang, J.
Angewandte Chemie International Edition. 2017;56(8):2156-61.

[Pubmed] [Link]

The highly acidic gastric environment creates a physiological barrier for using therapeutic drugs in the stomach. While proton pump inhibitors have been widely used for blocking acid-producing enzymes, this approach can cause various adverse effects. Reported herein is a new microdevice, consisting of magnesium-based micromotors which can autonomously and temporally neutralize gastric acid through efficient chemical propulsion in the gastric fluid by rapidly depleting the localized protons. Coating these micromotors with a cargo-containing pH-responsive polymer layer leads to autonomous release of the encapsulated payload upon gastric-acid neutralization by the motors. Testing in a mouse model demonstrate that these motors can safely and rapidly neutralize gastric acid and simultaneously release payload without causing noticeable acute toxicity or affecting the stomach function, and the normal stomach pH is restored within 24 h post motor administration.

2016

8. Enteric micromotor can selectively position and spontaneously propel in the gastrointestinal tract

Li J, Thamphiwatana S, Liu W, Esteban-Fernandez de Avila B, Angsantikul P, Sandraz E, Wang J, Xu T, Soto F, Ramez V, Wang X, Gao W, Zhang L, Wang J.
ACS Nano. 2016;10(10):9536-42.

[Pubmed] [Link]

The gastrointestinal (GI) tract, which hosts hundreds of bacteria species, becomes the most exciting organ for the emerging microbiome research. Some of these GI microbes are hostile and cause a variety of diseases. These bacteria colonize in different segments of the GI tract dependent on the local physicochemical and biological factors. Therefore, selectively locating therapeutic or imaging agents to specific GI segments is of significant importance for studying gut microbiome and treating various GI-related diseases. Herein, we demonstrate an enteric micromotor system capable of precise positioning and controllable retention in desired segments of the GI tract. These motors, consisting of magnesium-based tubular micromotors coated with an enteric polymer layer, act as a robust nanobiotechnology tool for site-specific GI delivery. The micromotors can deliver payload to a particular location via dissolution of their enteric coating to activate their propulsion at the target site toward localized tissue penetration and retention.

7. Nanoparticle‐Based Antivirulence Vaccine for the Management of Methicillin‐Resistant Staphylococcus aureus Skin Infection

Wang F, Fang RH, Luk BT, Hu CJ, Thamphiwatana S, Dehaini D, Angsantikul PKroll AV, Pang Z, Gao W, Lu W, Zhang L.
Advanced Functional Materials. 2016;26(10):1628-35.

[Pubmed] [Link]

With the rising threat of antibiotic‐resistant bacteria, vaccination is becoming an increasingly important strategy to prevent and manage bacterial infections. Made from deactivated bacterial toxins, toxoid vaccines are widely used in the clinic as they help to combat the virulence mechanisms employed by different pathogens. Here, the efficacy of a biomimetic nanoparticle‐based antivirulence vaccine is examined in a mouse model of methicillin‐resistant Staphylococcus aureus (MRSA) skin infection. Vaccination with nanoparticle‐detained staphylococcal α‐hemolysin (Hla) effectively triggers the formation of germinal centers and induces high anti‐Hla titers. Compared to mice vaccinated with control samples, those vaccinated with the nanoparticle toxoid show superior protective immunity against MRSA skin infection. The vaccination not only inhibits lesion formation at the site of bacterial challenge but also reduces the invasiveness of MRSA, preventing dissemination into other organs. Overall, this biomimetic nanoparticle‐based toxin detainment strategy is a promising method for the design of potent antivirulence vaccines for managing bacterial infections.

2015

6. Cell membrane-coated nanoparticles as an emerging antibacterial vaccine platform

Angsantikul P, Thamphiwatana S, Gao W, Zhang L.
Vaccines. 2015;3(4):814-28.

[Pubmed] [Link]

Nanoparticles have demonstrated unique advantages in enhancing immunotherapy potency and have drawn increasing interest in developing safe and effective vaccine formulations. Recent technological advancement has led to the discovery and development of cell membrane-coated nanoparticles, which combine the rich functionalities of cellular membranes and the engineering flexibility of synthetic nanomaterials. This new class of biomimetic nanoparticles has inspired novel vaccine design strategies with strong potential for modulating antibacterial immunity. This article will review recent progress on using cell membrane-coated nanoparticles for antibacterial vaccination. Specifically, two major development strategies will be discussed, namely (i) vaccination against virulence factors through bacterial toxin sequestration; and (ii) vaccination against pathogens through mimicking bacterial antigen presentation.

5. Nanoparticle biointerfacing by platelet membrane cloaking

Hu CM, Fang RH, Wang KC, Luk BT, Thamphiwatana S, Dehaini D, Nguyen P, Angsantikul PWen CH, Kroll AV, Carpenter C, Ramesh M, Qu V, Patel SH, Zhu J, Shi W, Hofman FM, Chen TC, Gao W, Zhang K, Chien S, Zhang L.
Nature. 2015;526(7571):118-21.

[Pubmed] [Link]

Development of functional nanoparticles can be encumbered by unanticipated material properties and biological events, which can affect nanoparticle effectiveness in complex, physiologically relevant systems. Despite the advances in bottom-up nanoengineering and surface chemistry, reductionist functionalization approaches remain inadequate in replicating the complex interfaces present in nature and cannot avoid exposure of foreign materials. Here we report on the preparation of polymeric nanoparticles enclosed in the plasma membrane of human platelets, which are a unique population of cellular fragments that adhere to a variety of disease-relevant substrates. The resulting nanoparticles possess a right-side-out unilamellar membrane coating functionalized with immunomodulatory and adhesion antigens associated with platelets. Compared to uncoated particles, the platelet membrane-cloaked nanoparticles have reduced cellular uptake by macrophage-like cells and lack particle-induced complement activation in autologous human plasma. The cloaked nanoparticles also display platelet-mimicking properties such as selective adhesion to damaged human and rodent vasculatures as well as enhanced binding to platelet-adhering pathogens. In an experimental rat model of coronary restenosis and a mouse model of systemic bacterial infection, docetaxel and vancomycin, respectively, show enhanced therapeutic efficacy when delivered by the platelet-mimetic nanoparticles. The multifaceted biointerfacing enabled by the platelet membrane cloaking method provides a new approach in developing functional nanoparticles for disease-targeted delivery.

4. Detoxification of organophosphate poisoning using nanoparticle bioscavengers

Pang Z, Hu CM, Fang RH, Luk BT, Gao W, Wang F, Chuluun E, Angsantikul PThamphiwatana S, Lu W, Jiang X, Zhang L.
 ACS Nano. 2015;9(6):6450-8.

[Pubmed] [Link]

Organophosphate poisoning is highly lethal as organophosphates, which are commonly found in insecticides and nerve agents, cause irreversible phosphorylation and inactivation of acetylcholinesterase (AChE), leading to neuromuscular disorders via accumulation of acetylcholine in the body. Direct interception of organophosphates in the systemic circulation thus provides a desirable strategy in treatment of the condition. Inspired by the presence of AChE on red blood cell (RBC) membranes, we explored a biomimetic nanoparticle consisting of a polymeric core surrounded by RBC membranes to serve as an anti-organophosphate agent. Through in vitro studies, we demonstrated that the biomimetic nanoparticles retain the enzymatic activity of membrane-bound AChE and are able to bind to a model organophosphate, dichlorvos, precluding its inhibitory effect on other enzymatic substrates. In a mouse model of organophosphate poisoning, the nanoparticles were shown to improve the AChE activity in the blood and markedly improved the survival of dichlorvos-challenged mice.

3. Hydrogel Retaining Toxin‐Absorbing Nanosponges for Local Treatment of Methicillin‐Resistant Staphylococcus aureus Infection

Wang F, Gao W, Thamphiwatana S, Luk BT, Angsantikul P, Zhang Q, Hu, CM, Fang RH, Copp, JA, Pornpattananangkul D, Lu W, Zhang, L.
Advanced Materials. 2015;27(22):3437-43.

[Pubmed] [Link]

A hybrid nanomaterial integrating unique toxin‐absorbing nanosponges with hydrogel is developed for local antivirulence therapy against methicillin‐resistant Staphylococcus aureus (MRSA) infection. The hydrogel composition is optimized to retain toxin nanosponges after administration while not compromising toxin transport into the gel for neutralization. Mice treated with the nanosponge–hydrogel hybrid show markedly reduced MRSA skin lesion development.

2. Modulating antibacterial immunity via bacterial membrane-coated nanoparticles

Gao W, Fang RH, Thamphiwatana S, Luk BT, Li J, Angsantikul P, Zhang Q, Hu CM, Zhang L.
Nano Letters. 2015;15(2):1403-9.

[Pubmed] [Link]

Synthetic nanoparticles coated with cellular membranes have been increasingly explored to harness natural cell functions toward the development of novel therapeutic strategies. Herein, we report on a unique bacterial membrane-coated nanoparticle system as a new and exciting antibacterial vaccine. Using Escherichia coli as a model pathogen, we collect bacterial outer membrane vesicles (OMVs) and successfully coat them onto small gold nanoparticles (AuNPs) with a diameter of 30 nm. The resulting bacterial membrane-coated AuNPs (BM-AuNPs) show markedly enhanced stability in biological buffer solutions. When injected subcutaneously, the BM-AuNPs induce rapid activation and maturation of dendritic cells in the lymph nodes of the vaccinated mice. In addition, vaccination with BM-AuNPs generates antibody responses that are durable and of higher avidity than those elicited by OMVs only. The BM-AuNPs also induce an elevated production of interferon gamma (INFγ) and interleukin-17 (IL-17), but not interleukin-4 (IL-4), indicating its capability of generating strong Th1 and Th17 biased cell responses against the source bacteria. These observed results demonstrate that using natural bacterial membranes to coat synthetic nanoparticles holds great promise for designing effective antibacterial vaccines.

2014

1. Nanoparticle approaches against bacterial infections

Gao W, Thamphiwatana S, Angsantikul P, Zhang L.
Wiley interdisciplinary reviews: nanomedicine and nanobiotechnology.  2014;6(6):532-47.

[Pubmed] [Link]

Despite the wide success of antibiotics, the treatment of bacterial infections still faces significant challenges, particularly the emergence of antibiotic resistance. As a result, nanoparticle drug delivery platforms including liposomes, polymeric nanoparticles, dendrimers, and various inorganic nanoparticles have been increasingly exploited to enhance the therapeutic effectiveness of existing antibiotics. This review focuses on areas where nanoparticle approaches hold significant potential to advance the treatment of bacterial infections. These areas include targeted antibiotic delivery, environmentally responsive antibiotic delivery, combinatorial antibiotic delivery, nanoparticle‐enabled antibacterial vaccination, and nanoparticle‐based bacterial detection. In each area we highlight the innovative antimicrobial nanoparticle platforms and review their progress made against bacterial infections.