Poly (lactide-co-glycolide)-Polymethacrylate Nanoparticles for Intramuscular Delivery of Plasmid Encoding Interleukin-10 to Prevent Autoimmune Diabetes in Mice

Synthetic-polymer-assisted antisense oligonucleotide delivery: targeted approaches for precision disease treatment

This review explores the recent advancements in polymer-assisted delivery systems for antisense oligonucleotides (ASOs) and their potential in precision disease treatment. Synthetic polymers have shown significant promise in enhancing the delivery, stability, and therapeutic efficacy of ASOs by addressing key challenges such as cellular uptake, endosomal escape, and reducing cytotoxicity. The review highlights key studies from the past decade demonstrating how these polymers improve gene silencing efficiencies, particularly in cancer and neurodegenerative disease models. Despite the progress achieved, barriers such as immunogenicity, delivery limitations, and scalability still need to be overcome for broader clinical application. Emerging strategies, including stimuli-responsive polymers and advanced nanoparticle systems, offer potential solutions to these challenges. The review underscores the transformative potential of polymer-enhanced ASO delivery in personalised medicine, emphasising the importance of continued innovation to optimise ASO-based therapeutics for more precise and effective disease treatments.

The Application of Nanomaterials in the Treatment of Pancreatic-Related Diseases

Pancreatic diseases, typically including pancreatic cancer, pancreatitis, and diabetes, pose enormous threats to people's lives and health. To date, therapeutics with high therapeutic efficacy and low side effects are still challenging. With the development of nanotechnology, nanomaterials have successfully been applied in pancretic disease treatment. Here, we first introduce the diversity of nanomaterials and the effects of their different physicochemical properties on pancreatic function. Following this, we analyze the potential of nanomaterials to enhance pancreatic targeting by overcoming the challenges of traditional delivery methods through surface modifications, structural adjustments, and optimized drug loading. Then, we introduce the application of structurally optimized nanomaterials to pancreatic-related diseases. For instance, on pancreatic cancer (as drug delivery platforms, for the promotion of radiation therapy, and as multifunctional tools), pancreatitis (as drug delivery systems, anti-inflammatory and anti-fibrotic agents), and diabetes (as insulin delivery carriers, for protecting pancreatic β cells, and for improving insulin resistance). Through analysis of the progress of current research, we summarize how nanomaterials can enhance treatment efficacy while minimizing side effects. Finally, we look forward to the prospects of nanomaterials in pancreatic disease treatment.

Engineering pH-sensitive dissolution of lipid-polymer nanoparticles by Eudragit integration impacts plasmid DNA (pDNA) transfection

Lipid-polymer nanoparticles offer a promising strategy for improving gene nanomedicines by combining the benefits of biocompatibility and stability associated with the individual systems. However, research to date has focused on poly-lactic-co-glycolic acid (PLGA) and resulted in inefficient transfection. In this study, biocompatible Eudragit constructs E100 and RS100 were formulated as lipid-polymer nanoparticles loaded with pDNA expressing red fluorescent protein (RFP) as a model therapeutic. Using a facile nanoprecipitation technique, a core-shell structure stabilised by lipid-polyethylene glycol (PEG) surfactant was produced and displayed resistance to ultracentrifugation. Both cationic polymers E100 (pH-sensitive dissolution at 5) and RS100 (pH-insensitive dissolution) produced 150-200 nm sized particles with a small positive surface charge (+3-5 mV) and high pDNA encapsulation efficiencies (EE) of 75-90%. The dissolution properties of the Eudragit polymers significantly impacted the biological performance in human embryonic kidney cells (HEK293T). Nanoparticles composed of polymer RS100 resulted in consistently high cell viability (80-100%), whereas polymer E100 demonstrated dose-dependent behaviour (20-90% cell viability). The low dissolution of polymer RS100 over the full pH range and the resulting nanoparticles failed to induce RFP expression in HEK293T cells. In contrast, polymer E100-constructed nanoparticles resulted in reproducible and gradually increasing RFP expression of 26-42% at 48-72 h. Intraperitoneal (IP) injection of the polymer E100-based nanoparticles in C57BL/6 mice resulted in targeted RFP expression in mouse testes with favourable biocompatibility one-week post-administration. These findings predicate Eudragit based lipid-polymer nanoparticles as a novel and effective carrier for nucleic acids, which could facilitate pre-clinical evaluation and translation of gene nanomedicines.

A Comprehensive Review on Prospects of Polymeric Nanoparticles for Treatment of Diabetes Mellitus: Receptors-Ligands, In vitro & In vivo Studies

As per International Diabetes Federation Report 2022, worldwide diabetes mellitus (DM) caused 6.7M moralities and ~537M adults suffering from diabetes mellitus. It is a chronic condition due to β-cell destruction or insulin resistance that leads to insulin deficiency. This review discusses Type-1 DM and Type-2 DM pathophysiology in detail, with challenges in management and treatment. The toxicity issues of conventional drugs and insulin injections are complex to manage. Thus, there is a need for technological intervention. In recent years, nanotechnology has found a fruitful advancement of novel drug delivery systems that might potentially increase the efficacy of anti-diabetic drugs. Amongst nano-formulations, polymeric nanoparticles have been studied to enhance the bioavailability and efficacy of anti-diabetic drugs and insulin. In the present review, we summarized polymeric nanoparticles with different polymers utilized to deliver anti-diabetic drugs with in vitro and in vivo studies. Furthermore, this review also includes the role of receptors and ligands in diabetes mellitus and the utilization of receptor-ligand interaction to develop targeted nanoparticles. Additionally, we discussed the utility of nanoparticles for the delivery of phytoconstituents which aids in protecting the oxidative stress generated during diabetes mellitus. Atlast, this article also comprises of numerous patents that have been filed or granted for the delivery of antidiabetic and anticancer molecules for the treatment of diabetes mellitus and pancreatic cancer.

A Systematic Overview of Eudragit® Based Copolymer for Smart Healthcare

Eudragit, synthesized by radical polymerization, is used for enteric coating, precise temporal release, and targeting the entire gastrointestinal system. Evonik Healthcare Germany offers different grades of Eudragit. The ratio of methacrylic acid to its methacrylate-based monomers used in the polymerization reaction defines the final product's characteristics and consequently its potential range of applications. Since 1953, these polymers have been made to use in a wide range of healthcare applications around the world. In this review, we reviewed the "known of knowns and known of unknowns" about Eudragit, from molecule to material design, its characterization, and its applications in healthcare.

Particle-Based therapies for antigen specific treatment of type 1 diabetes

Type 1 diabetes mellitus (T1D) is the leading metabolic disorder in children worldwide. Over time, incidence rates have continued to rise with 20 million individuals affected globally by the autoimmune disease. The current standard of care is costly and time-consuming requiring daily injections of exogenous insulin. T1D is mediated by autoimmune effector responses targeting autoantigens expressed on pancreatic islet β-cells. One approach to treat T1D is to skew the immune system away from an effector response by taking an antigen-specific approach to heighten a regulatory response through a therapeutic vaccine. An antigen-specific approach has been shown with soluble agents, but the effects have been limited. Micro or nanoparticles have been used to deliver a variety of therapeutic agents including peptides and immunomodulatory therapies to immune cells. Particle-based systems can be used to deliver cargo into the cell and microparticles can passively target phagocytic cells. Further, surface modification and controlled release of encapsulated cargo can enhance delivery over soluble agents. The induction of antigen-specific immune tolerance is imperative for the treatment of autoimmune diseases such as T1D. This review highlights studies that utilize particle-based platforms for the treatment of T1D.

The Progress of Non-Viral Materials and Methods for Gene Delivery to Skeletal Muscle

Since Jon A. Wolff found skeletal muscle cells being able to express foreign genes and Russell J. Mumper increased the gene transfection efficiency into the myocytes by adding polymers, skeletal muscles have become a potential gene delivery and expression target. Different methods have been developing to deliver transgene into skeletal muscles. Among them, viral vectors may achieve potent gene delivery efficiency. However, the potential for triggering biosafety risks limited their clinical applications. Therefore, non-viral biomaterial-mediated methods with reliable biocompatibility are promising tools for intramuscular gene delivery in situ. In recent years, a series of advanced non-viral gene delivery materials and related methods have been reported, such as polymers, liposomes, cell penetrating peptides, as well as physical delivery methods. In this review, we summarized the research progresses and challenges in non-viral intramuscular gene delivery materials and related methods, focusing on the achievements and future directions of polymers.

Predicting Drug Release Rate of Implantable Matrices and Better Understanding of the Underlying Mechanisms through Experimental Design and Artificial Neural Network-Based Modelling

There is a growing interest in implantable drug delivery systems (DDS) in pharmaceutical science. The aim of the present study is to investigate whether it is possible to customize drug release from implantable DDSs through drug-carrier interactions. Therefore, a series of chemically similar active ingredients (APIs) was mixed with different matrix-forming materials and was then compressed directly. Compression and dissolution interactions were examined by FT-IR spectroscopy. Regarding the effect of the interactions on drug release kinetics, a custom-made dissolution device designed for implantable systems was used. The data obtained were used to construct models based on artificial neural networks (ANNs) to predict drug dissolution. FT-IR studies confirmed the presence of H-bond-based solid-state interactions that intensified during dissolution. These results confirmed our hypothesis that interactions could significantly affect both the release rate and the amount of the released drug. The efficiencies of the kinetic parameter-based and point-to-point ANN models were also compared, where the results showed that the point-to-point models better handled predictive inaccuracies and provided better overall predictive efficiency.

Immunomodulatory and immunoregulatory nanomedicines for autoimmunity

Autoimmune diseases, caused by cellularly and molecularly complex immune responses against self-antigens, are largely treated with broad-acting, non-disease-specific anti-inflammatory drugs. These compounds can attenuate autoimmune inflammation, but tend to impair normal immunity against infection and cancer, cannot restore normal immune homeostasis and are not curative. Nanoparticle (NP)- and microparticle (MP)-based delivery of immunotherapeutic agents affords a unique opportunity to not only increase the specificity and potency of broad-acting immunomodulators, but also to elicit the formation of organ-specific immunoregulatory cell networks capable of inducing bystander immunoregulation. Here, we review the various NP/MP-based strategies that have so far been tested in models of experimental and/or spontaneous autoimmunity, with a focus on mechanisms of action.

Development and optimization of paclitaxel loaded Eudragit/PLGA nanoparticles by simplex lattice mixture design: Exploration of improved hemocompatibility and in vivo kinetics

Anemia is the most common hematological abnormality of chemotherapy, which is responsible for poor clinical outcomes. To overcome this complication, the present study was aimed for developing a Eudragit/polylactic-co-glycolic acid (PLGA) based nanoparticulate system for a model drug paclitaxel (PTX). The study was planned using a simplex lattice mixture design. PTX nanoparticles (PTXNp) were evaluated in vitro for physicochemical properties, hemolytic effects and cytotoxic effects. Further, the nanoparticles were subjected to in vivo screening using rats for hemocompatibility, pharmacokinetic profile, and biodistribution to the vital organs. The PTXNps were 65.77-214.73 nm in size, showed more than 60% sustained drug release in 360 h and caused less than 8% hemolysis. The parameters like red blood cell count, activated partial thromboplastin time (aPTT), prothrombin time (PT) and C3 complement were similar to the negative control. Cytotoxicity results suggested that all the PTXNp demonstrated drug concentration-dependent cytotoxicity. The in vivo pharmacokinetic study concluded that PTXNp formulations had significantly higher blood AUC (93.194.55-163,071.15 h*ng/mL), longer half-lives (5.80-6.35 h) and extended mean residence times (6.05-8.54 h) in comparison to PTX solution (p < 0.05). Overall, the study provides a nanoparticulate drug delivery system to deliver PTX safely and effectively along with reducing the associated hematological adverse effects.

Evolution of nanomedicines for the treatment of autoimmune disease: From vehicles for drug delivery to inducers of bystander immunoregulation

Over the last two decades, the nanomedicine field has witnessed an explosive growth of research on the development of nanoparticle/microparticle (NP/MP)-based compounds for the treatment of autoimmune diseases. Studies have evaluated compounds generated with a broad range of materials with different shapes, sizes, surface chemistries and structures. A number of active pharmaceutical ingredients, including immunosuppressants, cytokines, nucleotides, peptides, proteins and immunomodulators of various types have been encapsulated into or incorporated onto the surface of these compounds, either individually or in combination, and delivered to animal models of autoimmune inflammation via different administration routes. These NP/MP-based compounds can be categorized into four different groups based on their intended mechanisms of action. Here, we review the engineering designs, the pharmacodynamic and therapeutic correlates and the disease specificity of nanomedicines belonging to each of these groups.

Harnessing immunomodulatory mechanisms of Trichinella spiralis to design novel nanomedical approaches for restoring self-tolerance in autoimmunity

The rapid increase in the prevalence of autoimmune diseases in recent decades, especially in developed countries, coincided with improved living conditions and healthcare. Part of this increase could be ascribed to the lack of exposure to infectious agents like helminths that co-evolved with us and display potent immune regulatory actions. In this review we discussed many investigations, including our own, showing that Trichinella spiralis via its excretory-secretory products attenuate Th1/Th17 immunopathological response in autoimmunity and potentiate the protective Th2 and or regulatory T cell response, acting as an effective induction of tolerogenic dendritic cells (DCs), and probably mimicking the autoantigen in some diseases. A recent discovery of T. spiralis extracellular vesicles (TsEVs) suggested that inducing a complex regulation of the immune response requires simultaneous delivery of different signals in nano-sized packages. Indeed, different artificial nanomedical approaches discussed here suggested that co-delivery of multiple signals via nanoparticles is the most promising strategy for the treatment of autoimmune diseases. Although a long way is ahead of us before we could completely replicate natural nano-delivery systems which are both safe and potent in restoring self-tolerance, a clear path is being opened from a careful examination of parasite-host interactions.

Evaluation of the Benefits of Microfluidic-Assisted Preparation of Polymeric Nanoparticles for DNA Delivery

An effective delivery vehicle of genetic materials to their target site is the key to a successful gene therapy. In many cases, nanoparticles are used as the vehicle of choice and the efficiency of the delivery relies heavily on the physicochemical properties of the nanoparticles. Microfluidics, although being a low throughput method, has been increasingly researched for the preparation of nanoparticles. A range of superior properties were claimed in the literature for microfluidic-prepared platforms, but no evidence on direct comparison of the properties of the nanoparticles prepared by microfluidics and conventional high throughput method exists, leaving the industry with little guidance on how to select effective large-scale nanoparticle manufacturing method. This study used plasmid DNA-loaded PLGA-Eudragit nanoparticles as the model system to critically compare the nanoparticles prepared by conventional and microfluidics-assisted nanoprecipitation. The PLGA-Eudragit nanoparticles prepared by microfluidics were found to be statistically significantly larger than the ones prepared by conventional nanoprecipitation. PLGA-Eudragit nanoparticle prepared conventionally showed higher DNA loading efficiency. Although the DNA-loaded nanoparticles prepared by both methods did not induce significant cytotoxicity, the transfection efficiency was found to be higher for the ones prepared conventionally which has good potential for plasmid delivery. This study for the first time provides a direct comparison of the DNA-loaded nanoparticles prepared by microfluidic and conventional methods. The findings bring new insights into critical evaluation of the selection of manufacturing methods of nanoparticles for future gene therapy.

Diseases and conditions that impact maternal and fetal health and the potential for nanomedicine therapies

Maternal mortality rates in the United States have steadily increased since 1987 to the current rate of over 16 deaths per 100,000 live births. Whereas most of these deaths are related to an underlying condition, such as cardiovascular disease, many pregnant women die from diseases that emerge as a consequence of pregnancy. Both pre-existing and emergent diseases and conditions are difficult to treat in pregnant women because of the potential harmful effects of the treatment on the developing fetus. Often the health of the woman and the health of the baby are at odds and must be weighed against each other when medical treatment is needed, frequently leading to iatrogenic preterm birth. However, the use of engineered nanomedicines has the potential to fill the treatment gap for pregnant women. This review describes several conditions that may afflict pregnant women and fetuses and introduces how engineered nanomedicines may be used to treat these illnesses. Although the field of maternal-fetal nanomedicine is in its infancy, with additional research and development, engineered nanotherapeutics may greatly improve outcomes for pregnant women and their offspring in the future.

Solely aqueous formulation of hydrophobic cationic polymers for efficient gene delivery

Cationic polymers are promising gene delivery vectors due to their ability to bind and protect genetic material. The introduction of hydrophobic moieties into cationic polymers can further improve the vector efficiency, but common formulations of hydrophobic polymers involve harsh conditions such as organic solvents, impairing intactness and loading efficiency of the genetic material. In this study, a mild, aqueous formulation method for the encapsulation of high amounts of genetic material is presented. A well-defined pH-responsive hydrophobic copolymer, i.e. poly((n-butylmethacrylate)-co-(methylmethacrylate)-co-(2-(dimethylamino) ethylmethacrylate)), (PBMD) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization. Exploiting the pH-dependent solubility behavior of the polymer, stable pDNA loaded nanoparticles were prepared and characterized using analytical ultracentrifugation (AUC), cryo-transmission electron microscopy (cryo-TEM) and dynamic light scattering (DLS). This novel formulation approach showed high transfection efficiencies in HEK293T cells, while requiring 5- to 10-fold less pDNA compared to linear polyethylenimine (LPEI), in particular at short incubation times and in serum-containing media. Furthermore, the formulation was successfully adopted for siRNA and mRNA encapsulation and the commercially approved polymer Eudragit® E(PO/100). Overall, the aqueous formulation approach, accompanied by a tailor-made hydrophobic polymer and detailed physicochemical and application studies, led to improved gene delivery vectors with high potential for further applications.

Modulation of immune responses with nanoparticles and reduction of their immunotoxicity

Particles with a size range of 1-100 nm used in various fields of life sciences are called nanoparticles (NPs). Currently, nanotechnology has a wide range of applications in biomedical research, industries and in almost all types of modern technology. The growing applications of nanotechnology in medicine urge scientists to analyze the impact of NPs on human body tissues and the immune system. Easy surface modifications of the NPs enable the modulation of the immune system either by evading the immune system to prevent allergic reactions or by enhancing the immunogenic response. In this review, we discussed the various possible theories and practical implications reported to date for the applications of nanotechnology in immunostimulation and immunosuppression for favorable immune response, such as vaccine delivery and cancer treatments. In the last part of this paper, we also discussed the biocompatibility and unfavorable immunotoxicity of NPs and methods for lowering their toxicity.

Electrophoretic Deposition and Characterization of Chitosan/Eudragit E 100 Coatings on Titanium Substrate

Currently, a significant problem is the production of coatings for titanium implants, which will be characterized by mechanical properties comparable to those of a human bone, high corrosion resistance, and low degradation rate in the body fluids. This paper aims to describe the properties of novel chitosan/Eudragit E 100 (chit/EE100) coatings deposited on titanium grade 2 substrate by the electrophoretic technique (EPD). The deposition was carried out for different parameters like the content of EE100, time of deposition, and applied voltage. The microstructure, surface roughness, chemical and phase composition, wettability, mechanical and electrochemical properties, and degradation rate at different pH were examined in comparison to chitosan coating without the addition of Eudragit E 100. The applied deposition parameters significantly influenced the morphology of the coatings. The chit/EE100 coating with the highest homogeneity was obtained for Eudragit content of 0.25 g, at 10 V, and for 1 min. Young’s modulus of this sample (24.77 ± 5.50 GPa) was most comparable to that of human cortical bone. The introduction of Eudragit E 100 into chitosan coatings significantly reduced their degradation rate in artificial saliva at neutral pH while maintaining high sensitivity to pH changes. The chit/EE100 coatings showed a slightly lower corrosion resistance compared to the chitosan coating, however, significantly exceeding the substrate corrosion resistance. All prepared coatings were characterized by hydrophilicity.

Nano and Microparticle Emerging Strategies for Treatment of Autoimmune Diseases: Multiple Sclerosis and Type 1 Diabetes

Autoimmune diseases affect 10% of the world's population, and 1 in 200 people worldwide suffer from either multiple sclerosis (MS) or type 1 diabetes (T1D). While the targeted organ systems are different, MS and T1D share similarities in terms of autoreactive immune cells playing a critical role in pathogenesis. Both diseases can be managed only symptomatically without curative remission, and treatment options are limited and non-specific. Most current therapies cause some degree of systemic immune suppression, leaving the patients susceptible to opportunistic infections and other complications. Thus, there is considerable interest in the development of immunotherapies not associated with generalized immune suppression for these diseases. This review presents current and preclinical strategies for MS and T1D treatment, emphasizing those aimed to modulate the immune response, including the most recent strategies for tolerance induction. A central focus is on the emerging approaches using nano- and microparticle platforms, their evolution as immunotherapeutic carriers, including those incorporating specific antigens to induce tolerance and reduce unwanted generalized immune suppression.

Smart Thermosensitive Copolymer Incorporating Chitosan-Zinc-Insulin Electrostatic Complexes for Controlled Delivery of Insulin: Effect of Chitosan Chain Length

This work was designed to optimize thermosensitive copolymeric depot-based system for delivering insulin at a controlled rate for a prolonged period following a single subcutaneous injection. Intrinsic ability of insulin to form hexamers in the presence of zinc and electrostatic complexes with chitosan (CS) were explored for improving stability and release characteristics of insulin through the copolymeric depot. CS-zinc-insulin complexes were prepared using CS of different chain lengths (5, 30, 50, 200 kDa). Effect of different chain lengths of CS on the thermal stability, binding constant, and release profile of insulin was determined. Increasing chain length of CS demonstrated increasing thermal stability of insulin. However, higher chain length of CS adversely affected the release profile of insulin. Hydrolytic degradation analysis showed rapid degradation of copolymer in formulation containing higher chain length of CS (200 kDa)-zinc-insulin complexes, implying formation of bigger pores and channels in copolymeric matrix during initial release in this system. However, formulation containing smaller chain length of CS (5 kDa)-zinc-insulin complexes demonstrated slow copolymer degradation and sustained insulin release profile. Additionally, CS-zinc-insulin complexes were effective in preserving stability of insulin during the entire duration of release and storage.

Formation and Investigation of Electrospun Eudragit E100/Oregano Mats

An electrospun mat of Eudragit E100 (EE100) (a cationic copolymer based on dimethylaminoethyl methacrylate, butyl methacrylate, and methyl methacrylate) was used as a delivery system for oregano ethanolic extract (OEE). Oregano is a biologically active material which is widely used because of the antibacterial and antifungal activity. The oregano herb consists of phenolic compounds, the main of which are rosmarinic acid and from essential oil-carvacrol. Such a material could be an ideal candidate for oral drug systems. The influence of the EE100 concentration in the OEE on the structure of electrospun mats, encapsulation efficiency, dissolution profile, release kinetics and the stability of biologically active compounds was investigated. The concentration of the solution is a critical parameter for the structure and properties of electrospun mats. The diameter of electrospun fibers increased with the increase of EE100 concentration in the OEE. Electrospun mats obtained from 24% to 32% EE100 solutions showed high encapsulation efficiency, quick release and high stability of rosmarinic acid and carvacrol. Dissolution tests showed that 99% of carvacrol and 80% of rosmarinic acid were released after 10 min from electrospun nano-microfiber mats and capsules obtained from such formulations. The stability tests showed that physicochemical properties, dissolution profiles, and rosmarinic acid and carvacrol contents of the formulations were not significantly affected by storage.

Nanoparticles in tissue engineering: applications, challenges and prospects

Tissue engineering (TE) is an interdisciplinary field integrating engineering, material science and medical biology that aims to develop biological substitutes to repair, replace, retain, or enhance tissue and organ-level functions. Current TE methods face obstacles including a lack of appropriate biomaterials, ineffective cell growth and a lack of techniques for capturing appropriate physiological architectures as well as unstable and insufficient production of growth factors to stimulate cell communication and proper response. In addition, the inability to control cellular functions and their various properties (biological, mechanical, electrochemical and others) and issues of biomolecular detection and biosensors, all add to the current limitations in this field. Nanoparticles are at the forefront of nanotechnology and their distinctive size-dependent properties have shown promise in overcoming many of the obstacles faced by TE today. Despite tremendous progress in the use of nanoparticles over the last 2 decades, the full potential of the applications of nanoparticles in solving TE problems has yet to be realized. This review presents an overview of the diverse applications of various types of nanoparticles in TE applications and challenges that need to be overcome for nanotechnology to reach its full potential.

Stabilized single-injection inactivated polio vaccine elicits a strong neutralizing immune response

Vaccination in the developing world is hampered by limited patient access, which prevents individuals from receiving the multiple injections necessary for protective immunity. Here, we developed an injectable microparticle formulation of the inactivated polio vaccine (IPV) that releases multiple pulses of stable antigen over time. To accomplish this, we established an IPV stabilization strategy using cationic polymers for pH modulation to enhance traditional small-molecule-based stabilization methods. We investigated the mechanism of this strategy and showed that it was broadly applicable to all three antigens in IPV. Our lead formulations released two bursts of IPV 1 month apart, mimicking a typical vaccination schedule in the developing world. One injection of the controlled-release formulations elicited a similar or better neutralizing response in rats, considered the correlate of protection in humans, than multiple injections of liquid vaccine. This single-administration vaccine strategy has the potential to improve vaccine coverage in the developing world.

Modulating the immune system through nanotechnology

Nowadays, nanotechnology-based modulation of the immune system is presented as a cutting-edge strategy, which may lead to significant improvements in the treatment of severe diseases. In particular, efforts have been focused on the development of nanotechnology-based vaccines, which could be used for immunization or generation of tolerance. In this review, we highlight how different immune responses can be elicited by tuning nanosystems properties. In addition, we discuss specific formulation approaches designed for the development of anti-infectious and anti-autoimmune vaccines, as well as those intended to prevent the formation of antibodies against biologicals.

Enhanced gastric retention and drug release via development of novel floating microspheres based on Eudragit E100 and polycaprolactone: synthesis and in vitro evaluation

Eudragit E 100 and polycaprolactone (PCL) floating microspheres for enhanced gastric retention and drug release were successfully prepared by oil in water solvent evaporation method. Metronidazole benzoate, an anti-protozoal drug, was used as a model drug. Polyvinyl alcohol was used as an emulsifier. The prepared microspheres were observed for % recovery, % degree of hydration, % water uptake, % drug loading, % buoyancy and % drug release. The physico-chemical properties of the microspheres were studied by calculating encapsulation efficiency of microspheres and drug release kinetics. Drug release characteristics of microspheres were studied in simulated gastric fluid and simulated intestinal fluid i.e., at pH 1.2 and 7.4 respectively. Fourier transform infrared spectroscopy was used to reveal the chemical interaction between drug and polymers. Scanning electron microscopy was conducted to study the morphology of the synthesized microspheres.

An update on applications of nanostructured drug delivery systems in cancer therapy: a review

Cancer is a main public health problem that is known as a malignant tumor and out-of-control cell growth, with the potential to assault or spread to other parts of the body. Recently, remarkable efforts have been devoted to develop nanotechnology to improve the delivery of anticancer drug to tumor tissue as minimizing its distribution and toxicity in healthy tissue. Nanotechnology has been extensively used in the advance of new strategies for drug delivery and cancer therapy. Compared to customary drug delivery systems, nano-based drug delivery method has greater potential in different areas, like multiple targeting functionalization, in vivo imaging, extended circulation time, systemic control release, and combined drug delivery. Nanofibers are used for different medical applications such as drug delivery systems.

Cancer nanoimmunotherapy using advanced pharmaceutical nanotechnology

Immunotherapy is a promising option for cancer treatment that might cure cancer with fewer side effects by primarily activating the host's immune system. However, the effect of traditional immunotherapy is modest, frequently due to tumor escape and resistance of multiple mechanisms. Pharmaceutical nanotechnology, which is also called cancer nanotechnology or nanomedicine, has provided a practical solution to solve the limitations of traditional immunotherapy. This article reviews the latest developments in immunotherapy and nanomedicine, and illustrates how nanocarriers (including micelles, liposomes, polymer-drug conjugates, solid lipid nanoparticles and biodegradable nanoparticles) could be used for the cellular transfer of immune effectors for active and passive nanoimmunotherapy. The fine engineering of nanocarriers based on the unique features of the tumor microenvironment and extra-/intra-cellular conditions of tumor cells can greatly tip the triangle immunobalance among host, tumor and nanoparticulates in favor of antitumor responses, which shows a promising prospect for nanoimmunotherapy.

An implantable active-targeting micelle-in-nanofiber device for efficient and safe cancer therapy

Nanocarriers have attracted broad attention in cancer therapy because of their ability to carry drugs preferentially into cancer tissue, but their application is still limited due to the systemic toxicity and low delivery efficacy of intravenously delivered chemotherapeutics. In this study, we develop a localized drug delivery device with combination of an active-targeting micellar system and implantable polymeric nanofibers. This device is achieved first by the formation of hydrophobic doxorubicin (Dox)-encapsulated active-targeting micelles assembled from a folate-conjugated PCL-PEG copolymer. Then, fabrication of the core-shell polymeric nanofibers is achieved with coaxial electrospinning in which the core region consists of a mixture of poly(vinyl alcohol) and the micelles and the outer shell layer consists of cross-linked gelatin. In contrast to the systematic administration of therapeutics via repeatedly intravenous injections of micelles, this implantable device has these capacities of greatly reducing the drug dose, the frequency of administration and side effect of chemotherapeutic agents while maintaining highly therapeutic efficacy against artificial solid tumors. This micelle-based nanofiber device can be developed toward the next generation of nanomedicine for efficient and safe cancer therapy.

Clearance of pathological antibodies using biomimetic nanoparticles

Pathological antibodies have been demonstrated to play a key role in type II immune hypersensitivity reactions, resulting in the destruction of healthy tissues and leading to considerable morbidity for the patient. Unfortunately, current treatments present significant iatrogenic risk while still falling short for many patients in achieving clinical remission. In the present work, we explored the capability of target cell membrane-coated nanoparticles to abrogate the effect of pathological antibodies in an effort to minimize disease burden, without the need for drug-based immune suppression. Inspired by antibody-driven pathology, we used intact RBC membranes stabilized by biodegradable polymeric nanoparticle cores to serve as an alternative target for pathological antibodies in an antibody-induced anemia disease model. Through both in vitro and in vivo studies, we demonstrated efficacy of RBC membrane-cloaked nanoparticles to bind and neutralize anti-RBC polyclonal IgG effectively, and thus preserve circulating RBCs.

Immunosuppressive and anti-inflammatory properties of engineered nanomaterials

Nanoparticle interactions with various components of the immune system are determined by their physicochemical properties such as size, charge, hydrophobicity and shape. Nanoparticles can be engineered to either specifically target the immune system or to avoid immune recognition. Nevertheless, identifying their unintended impacts on the immune system and understanding the mechanisms of such accidental effects are essential for establishing a nanoparticle's safety profile. While immunostimulatory properties have been reviewed before, little attention in the literature has been given to immunosuppressive and anti-inflammatory properties. The purpose of this review is to fill this gap. We will discuss intended immunosuppression achieved by either nanoparticle engineering, or the use of nanoparticles to carry immunosuppressive or anti-inflammatory drugs. We will also review unintended immunosuppressive properties of nanoparticles per se and consider how such properties could be either beneficial or adverse.

Research Spotlight: Functionalized nanoparticles for future cardiovascular medicine

All research investment has the goal of improving quality of life and health status. In recent years, the emerging technologies in nanomedicine research provide us a new frontier in the fight against human disease. By taking advantage of the unique physicochemical properties of nanoparticles (NPs), nanomedicine where drugs are blended into nanomaterials readily offers a wide range of applications in the tracing, diagnosis and treatment of disease. Although the application of therapeutic NPs is predominantly for cancer treatment, growing evidence has demonstrated the feasibility and potency of utilizing NPs for cardiovascular disease therapy. However, more consideration is required in this aspect due to limitations such as unfavorable particle retention in the contractile heart and the lack of cardiomyocyte markers for targeting.

Designed nanocage displaying ligand-specific Peptide bunches for high affinity and biological activity

Protein-cage nanoparticles are promising multifunctional platforms for targeted delivery of imaging and therapeutic agents owing to their biocompatibility, biodegradability, and low toxicity. The major advantage of protein-cage nanoparticles is the ability to decorate their surfaces with multiple functionalities through genetic and chemical modification to achieve desired properties for therapeutic and/or diagnostic purposes. Specific peptides identified by phage display can be genetically fused onto the surface of cage proteins to promote the association of nanoparticles with a particular cell type or tissue. Upon symmetrical assembly of the cage, peptides are clustered on the surface of the cage protein in bunches. The resulting PBNC (peptide bunches on nanocage) offers the potential of synergistically increasing the avidity of the peptide ligands, thereby enhancing their blocking ability for therapeutic purposes. Here, we demonstrated a proof-of-principle of PBNCs, fusing the interleukin-4 receptor (IL-4R)-targeting peptide, AP-1, identified previously by phage display, with ferritin-L-chain (FTL), which undergoes 24-subunit assembly to form highly stable AP-1-containing nanocage proteins (AP1-PBNCs). AP1-PBNCs bound specifically to the IL-4R-expressing cell line, A549, and their binding and internalization were specifically blocked by anti-IL-4R antibody. AP1-PBNCs exhibited dramatically enhanced binding avidity to IL-4R compared with AP-1 peptide, measured by surface plasmon resonance spectroscopy. Furthermore, treatment with AP1-PBNCs in a murine model of experimental asthma diminished airway hyper-responsiveness and eosinophilic airway inflammation along with decreased mucus hyperproduction. These findings hold great promise for the application of various PBNCs with ligand-specific peptides in therapeutics for different diseases, such as cancer.

Chitosans for delivery of nucleic acids

Alternatives to efficient viral vectors in gene therapy are desired because of their poor safety profiles. Chitosan is a promising non-viral nucleotide delivery vector because of its biocompatibility, biodegradability, low immunogenicity and ease of manufacturing. Since the transfection efficiency of chitosan polyplexes is relatively low compared to viral counterparts, there is an impetus to gain a better understanding of the structure-performance relationship. Recent progress in preparation and characterisation has enabled coupling analysis of chitosans structural parameters that has led to increased TE by tailoring of chitosan's structure. In this review, we summarize the recent advances that have lead to a more rational design of chitosan polyplexes. We present an integrated review of all major areas of chitosan-based transfection, including preparation, chitosan and polyplexes physicochemical characterisation, in vitro and in vivo assessment. In each, we present the obstacles to efficient transfection and the strategies adopted over time to surmount these impediments.

Biopolymer-based nanoparticles for drug/gene delivery and tissue engineering

There has been a great interest in application of nanoparticles as biomaterials for delivery of therapeutic molecules such as drugs and genes, and for tissue engineering. In particular, biopolymers are suitable materials as nanoparticles for clinical application due to their versatile traits, including biocompatibility, biodegradability and low immunogenicity. Biopolymers are polymers that are produced from living organisms, which are classified in three groups: polysaccharides, proteins and nucleic acids. It is important to control particle size, charge, morphology of surface and release rate of loaded molecules to use biopolymer-based nanoparticles as drug/gene delivery carriers. To obtain a nano-carrier for therapeutic purposes, a variety of materials and preparation process has been attempted. This review focuses on fabrication of biocompatible nanoparticles consisting of biopolymers such as protein (silk, collagen, gelatin, β-casein, zein and albumin), protein-mimicked polypeptides and polysaccharides (chitosan, alginate, pullulan, starch and heparin). The effects of the nature of the materials and the fabrication process on the characteristics of the nanoparticles are described. In addition, their application as delivery carriers of therapeutic drugs and genes and biomaterials for tissue engineering are also reviewed.

Biocompatibility of engineered nanoparticles for drug delivery

The rapid advancement of nanotechnology has raised the possibility of using engineered nanoparticles that interact within biological environments for treatment of diseases. Nanoparticles interacting with cells and the extracellular environment can trigger a sequence of biological effects. These effects largely depend on the dynamic physicochemical characteristics of nanoparticles, which determine the biocompatibility and efficacy of the intended outcomes. Understanding the mechanisms behind these different outcomes will allow prediction of the relationship between nanostructures and their interactions with the biological milieu. At present, almost no standard biocompatibility evaluation criteria have been established, in particular for nanoparticles used in drug delivery systems. Therefore, an appropriate safety guideline of nanoparticles on human health with assessable endpoints is needed. In this review, we discuss the data existing in the literature regarding biocompatibility of nanoparticles for drug delivery applications. We also review the various types of nanoparticles used in drug delivery systems while addressing new challenges and research directions. Presenting the aforementioned information will aid in getting one step closer to formulating compatibility criteria for biological systems under exposure to different nanoparticles.

Immuno-isolation of pancreatic islet allografts using pegylated nanotherapy leads to long-term normoglycemia in full MHC mismatch recipient mice

Two major hurdles need to be surmounted for cell therapy for diabetes: (i) allo-immune rejection of grafted pancreatic islets, or stem/precursor cell-derived insulin-secreting cells; and (ii) continuing auto-immunity against the diabetogenic endogenous target antigen. Nanotherapeutics offer a novel approach to overcome these problems and here we ask if creation of “stealth” islets encapsulated within a thin cage of pegylated material of 100–200 nanometers thick provides a viable option for islet transplantation. The aims of this study were to test islet viability and functionality following encapsulation within the pegylated cage, and functional efficacy in vivo in terms of graft-derived control of normoglycemia in diabetic mice. We first demonstrated that pegylation of the islet surface, plus or minus nanoparticles, improved long-term islet viability in vitro compared to non-pegylated (naked) control islets. Moreover, pegylation of the islets with nanoparticles was compatible with glucose-stimulated insulin secretion and insulin biogenesis. We next looked for functionality of the created “stealth” DBA/2 (H-2^d) islets in vivo by comparing glycemic profiles across 4 groups of streptozotozin-induced diabetic C57BL/6 (H-2^b) recipients of (i) naked islets; (ii) pegylated islets; (iii) pegylated islets with nanoparticles (empty); and (iv) pegylated islets with nanoparticles loaded with a cargo of leukemia inhibitory factor (LIF), a factor both promotes adaptive immune tolerance and regulates pancreatic β cell mass. Without any other treatment, normoglycemia was lost after 17 d (+/−7.5 d) in control group. In striking contrast, recipients in groups (ii), (iii), and (iv) showed long-term (>100 d) normoglycemia involving 30%; 43%, and 57% of the recipients in each respective group. In conclusion, construction of “stealth” islets by pegylation-based nanotherapeutics not only supports islet structure and function, but also effectively isolates the islets from immune-mediated destruction. The added value of nanoparticles to deliver immune modulators plus growth factors such as LIF expands the potential of this novel therapeutic approach to cell therapy for diabetes.

Poly(ε-caprolactone), Eudragit® RS 100 and poly(ε-caprolactone)/Eudragit® RS 100 blend submicron particles for the sustained release of the antiretroviral efavirenz

The design of simple and scalable drug delivery systems to target the central nervous system (CNS) could represent a breakthrough in the addressment of the HIV-associated neuropathogenesis. The intranasal (i.n.) route represents a minimally invasive strategy to surpass the blood-brain barrier, though it demands the use of appropriate nanocarriers bearing high drug payloads and displaying sufficiently long residence time. The present work explored the development of submicron particles made of poly(ε-caprolactone) (PCL), Eudragit(®) RS 100 (RS a copolymer of ethylacrylate, methylmethacrylate and methacrylic acid esterified with quaternary ammonium groups) and their blends, loaded with the first-choice antiretroviral efavirenz (EFV) as an approach to fine tune the particle size and the release kinetics. Particles displaying hydrodynamic diameters between 90 and 530 nm were obtained by two methods: nanoprecipitation and emulsion/solvent diffusion/evaporation. In general, the former resulted in smaller particles and narrower size distributions. The encapsulation efficiency was greater than 94%, the drug weight content approximately 10% and the yield in the 72.5-90.0% range. The highly positive surface (>+30 mV) rendered the suspensions physically stable for more than one month. In vitro release assays indicated that the incorporation of the poly(methacrylate) into the composition reduced the burst effect and slowed the release rate down with respect to pure poly(ε-caprolactone) particles. The analysis of the release profile indicated that, in all cases, the kinetics adjusted well to the Higuchi model with R(adj)(2) values >0.9779. These findings suggested that the release was mainly controlled by diffusion. In addition, when data were analyzed by the Korsmeyer-Peppas model, n values were in the 0.520-0.587 range, indicating that the drug release was accomplished by the combination of two phenomena: diffusion and polymer chain relaxation. Based on ATR/FT-IR analysis that investigated drug/polymer matrix interactions, the potential role of the hydrophobic interactions of C-F groups of EFV with carbonyl groups in the backbone of PCL and poly(methacrylate) could be ruled out. The developed EFV-loaded particles appear as a useful platform to investigate the intranasal administration to increase the bioavailability in the CNS.

A strategy in the design of micellar shape for cancer therapy

For cancer therapy, optimization of carrier features is necessary to effectively deliver the targeting agents to tumor sites. Biodegradable poly(ether-anhydrides) micelles with filamentous, rod-like, and spherical shapes are fabricated. Their size and morphology are characterized by AFM and TEM. The encapsulation of doxorubicin hydrochloride (DOX) into the micelles does not impact their shape. The effect of micellar shape on the drug loading capacity and encapsulation efficiency, as well as in vitro drug release, is investigated. The cellular uptakes are evaluated using fluorescence microscopy, confocal laser scanning microscopy and flow cytometry on co-cultures of human hepatoblastoma cell line (HepG2), lung epithelial cancer cell line (A549), and human nasopharyngeal epidermoid carcinoma cells (KB) and fibroblast normal cells mixed with the different shapes of DOX-loaded micelles. The results show that the spherical DOX-loaded micelles are more readily taken up by all types of cells. The impact of micellar shape on in vivo antitumor function is also assessed from changes of tumor volume, body weight loss, and survival rate of 4T1-bearing mice and the immunostaining of tumor sections for analysis of tumor cell proliferation. The results reveal that the filamentous DOX-loaded micelles possess the highest safety to body and the best therapeutic effects to artificial solid tumors. Therefore, the filamentous shape is deemed the most suitable morphology for design and engineering of drug vehicles for cancer therapy.