Current advances in research and clinical applications of PLGA-based nanotechnology

The autophagy-lysosome pathway: a potential target in the chemical and gene therapeutic strategies for Parkinson's disease

Parkinson's disease is a common neurodegenerative disease with movement disorders associated with the intracytoplasmic deposition of aggregate proteins such as α-synuclein in neurons. As one of the major intracellular degradation pathways, the autophagy-lysosome pathway plays an important role in eliminating these proteins. Accumulating evidence has shown that upregulation of the autophagy-lysosome pathway may contribute to the clearance of α-synuclein aggregates and protect against degeneration of dopaminergic neurons in Parkinson's disease. Moreover, multiple genes associated with the pathogenesis of Parkinson's disease are intimately linked to alterations in the autophagy-lysosome pathway. Thus, this pathway appears to be a promising therapeutic target for treatment of Parkinson's disease. In this review, we briefly introduce the machinery of autophagy. Then, we provide a description of the effects of Parkinson's disease-related genes on the autophagy-lysosome pathway. Finally, we highlight the potential chemical and genetic therapeutic strategies targeting the autophagy-lysosome pathway and their applications in Parkinson's disease.

Evaluation of PLGA, lipid-PLGA hybrid nanoparticles, and cationic pH-sensitive liposomes as tuberculosis vaccine delivery systems in a Mycobacterium tuberculosis challenge mouse model - A comparison

Tuberculosis (TB) continues to pose a global threat for millennia, currently affecting over 2 billion people and causing 10.6 million new cases and 1.3 million deaths annually. The only existing vaccine, Mycobacterium Bovis Bacillus Calmette-Guérin (BCG), provides highly variable and inadequate protection in adults and adolescents. This study explores newly developed subunit tuberculosis vaccines that use a multistage protein fusion antigen Ag85b-ESAT6-Rv2034 (AER). The protection efficacy, as well as in vivo induced immune responses, were compared for five vaccines: BCG; AER-CpG/MPLA mix; poly(D,L-lactic-co-glycolic acid) (PLGA); lipid-PLGA hybrid nanoparticles (NPs); and cationic pH-sensitive liposomes (the latter three delivering AER together with CpG and MPLA). All vaccines, except the AER-adjuvant mix, induced protection in Mycobacterium tuberculosis (Mtb)-challenged C57/Bl6 mice as indicated by a significant reduction in bacterial burden in lungs and spleens of the animals. Four AER-based vaccines significantly increased the number of circulating multifunctional CD4+ and CD8+ T-cells producing IL-2, IFNγ, and TNFα, exhibiting a central memory phenotype. Furthermore, AER-based vaccines induced an increase in CD69+ B-cell counts as well as high antigen-specific antibody titers. Unexpectedly, none of the observed immune responses were associated with the bacterial burden outcome, such that the mechanism responsible for the observed vaccine-induced protection of these vaccines remains unclear. These findings suggest the existence of non-classical protective mechanisms for Mtb infection, which could, once identified, provide interesting targets for novel vaccines.

Polymer-drug conjugates: revolutionizing nanotheranostic agents for diagnosis and therapy

Nanotheranostics, an amalgamation of therapeutic and diagnostic capabilities at the nanoscale, is revolutionizing personalized medicine. Polymer-drug conjugates (PDCs) stand at the forefront of this arena, offering a multifaceted approach to treat complex diseases such as cancer. This review explores the recent advancements in PDCs, highlighting their design principles, working mechanisms, and the therapeutic applications. We discuss the incorporation of imaging agents into PDCs that allow for real-time monitoring of drug delivery and treatment efficacy. With the aim of improving patient care, the review examines how PDCs enable targeted drug delivery, minimize side effects, and provide valuable diagnostic data, hence enhancing the precision of medical interventions. We also address the challenges facing the clinical translation of PDCs, such as scalability, regulatory hurdles, and cost-effectiveness, providing a comprehensive outlook on the future of nanotheranostics in patient management.

Biodegradable stimulating electrodes for resident neural stem cell activation in vivo

Brain stimulation has been recognized as a clinically effective strategy for treating neurological disorders. Endogenous brain neural precursor cells (NPCs) have been shown to be electrosensitive cells that respond to electrical stimulation by expanding in number, undergoing directed cathodal migration, and differentiating into neural phenotypes in vivo, supporting the application of electrical stimulation to promote neural repair. In this study, we present the design of a flexible and biodegradable brain stimulation electrode for temporally regulated neuromodulation of NPCs. Leveraging the cathodally skewed electrochemical window of molybdenum and the volumetric charge transfer properties of conductive polymer, we engineered the electrodes with high charge injection capacity for the delivery of biphasic monopolar stimulation. We demonstrate that the electrodes are biocompatible and can deliver an electric field sufficient for NPC activation for 7 days post implantation before undergoing resorption in physiological conditions, thereby eliminating the need for surgical extraction. The biodegradable electrode demonstrated its potential to be used for NPC-based neural repair strategies.

Tissue engineering approaches for dental pulp regeneration: The development of novel bioactive materials using pharmacological epigenetic inhibitors

The drive for minimally invasive endodontic treatment strategies has shifted focus from technically complex and destructive root canal treatments towards more conservative vital pulp treatment. However, novel approaches to maintaining dental pulp vitality after disease or trauma will require the development of innovative, biologically-driven regenerative medicine strategies. For example, cell-homing and cell-based therapies have recently been developed in vitro and trialled in preclinical models to study dental pulp regeneration. These approaches utilise natural and synthetic scaffolds that can deliver a range of bioactive pharmacological epigenetic modulators (HDACis, DNMTis, and ncRNAs), which are cost-effective and easily applied to stimulate pulp tissue regrowth. Unfortunately, many biological factors hinder the clinical development of regenerative therapies, including a lack of blood supply and poor infection control in the necrotic root canal system. Additional challenges include a need for clinically relevant models and manufacturing challenges such as scalability, cost concerns, and regulatory issues. This review will describe the current state of bioactive-biomaterial/scaffold-based engineering strategies to stimulate dentine-pulp regeneration, explicitly focusing on epigenetic modulators and therapeutic pharmacological inhibition. It will highlight the components of dental pulp regenerative approaches, describe their current limitations, and offer suggestions for the effective translation of novel epigenetic-laden bioactive materials for innovative therapeutics.

Interface/Dipole Polarized Antibiotics-Loaded Fe3O4/PB Nanoparticles for Non-Invasive Therapy of Osteomyelitis Under Medical Microwave Irradiation

Due to their poor light penetration, photothermal therapy and photodynamic therapy are ineffective in treating deep tissue infections, such as osteomyelitis caused by Staphylococcus aureus (S. aureus). Here, a microwave (MW)-responsive magnetic targeting composite system consisting of ferric oxide (Fe3O4)/Prussian blue (PB) nanoparticles, gentamicin (Gent), and biodegradable poly(lactic-co-glycolic acid) (PLGA) is reported. The PLGA/Fe3O4/PB/Gent complex is used in combination with MW thermal therapy (MTT), MW dynamic therapy (MDT), and chemotherapy (CT) to treat acute osteomyelitis infected with S. aureus-infected. The powerful antibacterial effect of the PLGA/Fe3O4/PB/Gent is determined by the synergistic effects of heat and reactive oxygen species (ROS) generation by the Fe3O4/PB nanoparticles under MW irradiation and the effective release of Gent at the infection site via magnetic targeting. The antibacterial mechanism of the PLGA/Fe3O4/PB/Gent under MW irradiation is analyzed using bacterial transcriptome RNA sequencing. The MW heat and ROS reduce the activity of the protein transporters on the bacterial membrane, along with the transport of various ions and the acceleration of phosphate metabolism, which can lead to increased permeability of the bacterial membrane, damage the ribosome and DNA, and accompany the internal protein efflux of the bacteria, thus effectively killing the bacteria.

Electrospun poly(ε-caprolactone)/poly(glycerol sebacate) aligned fibers fabricated with benign solvents for tendon tissue engineering

The electrospinning technique is a commonly employed approach to fabricate fibers intended for various tissue engineering applications. The aim of this study is to develop a novel strategy for tendon repair through the use of aligned poly(ε-caprolactone) (PCL) and poly(glycerol sebacate) (PGS) fibers fabricated in benign solvents, and further explore the potential application of PGS in tendon tissue engineering (TTE). The fibers were characterized for their morphological and physicochemical properties; amniotic epithelial stem cells (AECs) were used to assess the fibers teno-inductive and immunomodulatory potential due to their ability to teno-differentiate undergoing first a stepwise epithelial to mesenchymal transition, and due to their documented therapeutic role in tendon regeneration. The addition of PGS to PCL improved the spinnability of the polymer solution, as well as the uniformity and directionality of the so-obtained fibers. The mechanical properties were in the range of most TTE applications, specifically in the case of PCL/PGS 4:1 and 2:1 ratios. Compared to PCL alone, the same ratios also allowed a better AECs infiltration and growth over 7 days of culture, and triggered the activation of tendon-related genes (SCX, COL1, TNMD) and the expression of tenomodulin (TNMD) at the protein level. Concerning the immunomodulatory properties, both PCL and PCL/PGS fibers negatively affected the immunomodulatory profile of AECs, up-regulating both anti-inflammatory (IL-10) and pro-inflammatory (IL-12) cytokines over 7 days of culture. Overall, PCL/PGS 2:1 fibers fabricated with benign solvents proved to be the most suitable composition for TTE application based on their topographical cues, mechanical properties, biocompatibility, and teno-inductive properties.

Recent Applications of PLGA in Drug Delivery Systems

Poly(lactic-co-glycolic acid) (PLGA) is a widely used biodegradable and biocompatible copolymer in drug delivery systems (DDSs). In this article, we highlight the critical physicochemical properties of PLGA, including its molecular weight, intrinsic viscosity, monomer ratio, blockiness, and end caps, that significantly influence drug release profiles and degradation times. This review also covers the extensive literature on the application of PLGA in delivering small-molecule drugs, proteins, peptides, antibiotics, and antiviral drugs. Furthermore, we discuss the role of PLGA-based DDSs in the treating various diseases, including cancer, neurological disorders, pain, and inflammation. The incorporation of drugs into PLGA nanoparticles and microspheres has been shown to enhance their therapeutic efficacy, reduce toxicity, and improve patient compliance. Overall, PLGA-based DDSs holds great promise for the advancement of the treatment and management of multiple chronic conditions.

Poly(lactic-co-glycolic acid) nanoparticle fabrication, functionalization, and biological considerations for drug delivery

Nanoparticles can be used for drug delivery and consist of many sizes and chemical compositions. They can accommodate a diverse population of drugs and can be made to target specific areas of the body. Fabrication methods generally follow either top-down or bottom-up manufacturing techniques, which have differing production controls, which determine nanoparticle characteristics including but not limited to size and encapsulation efficiency. Functionalizing these nanoparticles is done to add drugs, prevent aggregation, add positive charge, add targeting, etc. As the nanoparticles reach the target cells, cellular uptake occurs, drug is released, and the nanoparticle is broken down. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles have often been used for drug delivery applications as they have shown minimal toxicity, which has helped with US FDA approval. This review breaks down PLGA nanoparticle fabrication, functionalization, and biological considerations.

Nanomaterials: innovative approaches for addressing key objectives in periodontitis treatment

Periodontitis is a chronic inflammatory disease primarily caused by dental plaque, which is a significant global public health concern due to its high prevalence and severe impact on oral, and even systemic diseases. The current therapeutic plan focuses on three objectives: pathogenic bacteria inhibition, inflammation control, and osteogenic differentiation induction. Existing treatments still have plenty of drawbacks, thus, there is a pressing need for novel methods to achieve more effective treatment effects. Nanomaterials, as emerging materials, have been proven to exert their inherent biological properties or serve as stable drug delivery platforms, which may offer innovative solutions in periodontitis treatment. Nanomaterials utilized in periodontitis treatment fall into two categories, organic and inorganic nanomaterials. Organic nanomaterials are known for their biocompatibility and their potential to promote tissue regeneration and cell functions, including natural and synthetic polymers. Inorganic nanomaterials, such as metal, oxides, and mesoporous silica nanoparticles, exhibit unique physicochemical properties that make them suitable as antibacterial agents and drug delivery platforms. The inorganic nanosurface provides terrain induction for cell migration and osteogenic regeneration at defect sites by introducing different surface morphologies. Inorganic nanomaterials also play a role in antibacterial photodynamic therapy (aPDT) for eliminating pathogenic bacteria in the oral cavity. In this review, we will introduce multiple forms and applications of nanomaterials in periodontitis treatment and focus on their roles in addressing the key therapeutic objectives, to emphasize their promising future in achieving more effective and patient-friendly approaches toward periodontal tissue regeneration and overall health.

Revolutionizing adjuvant development: harnessing AI for next-generation cancer vaccines

With the COVID-19 pandemic, the importance of vaccines has been widely recognized and has led to increased research and development efforts. Vaccines also play a crucial role in cancer treatment by activating the immune system to target and destroy cancer cells. However, enhancing the efficacy of cancer vaccines remains a challenge. Adjuvants, which enhance the immune response to antigens and improve vaccine effectiveness, have faced limitations in recent years, resulting in few novel adjuvants being identified. The advancement of artificial intelligence (AI) technology in drug development has provided a foundation for adjuvant screening and application, leading to a diversification of adjuvants. This article reviews the significant role of tumor vaccines in basic research and clinical treatment and explores the use of AI technology to screen novel adjuvants from databases. The findings of this review offer valuable insights for the development of new adjuvants for next-generation vaccines.

Development of α-Tocopherol Loaded PLGA Nanoparticles and Its Evaluation as a Novel Immune Adjuvant

With the continuous development of preventive and therapeutic vaccines, traditional adjuvants cannot provide sufficient immune efficacy and it is of high necessity to develop safe and effective novel nanoparticle-based vaccine adjuvants. α-Tocopherol (TOC) is commonly used in oil-emulsion adjuvant systems as an immune enhancer, yet its bioavailability is limited by poor water solubility. This study aims to develop TOC-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (TOC-PLGA NPs) to explore the potential of TOC-PLGA NPs as a novel nanoparticle-immune adjuvant. TOC-PLGA NPs are prepared by a nanoprecipitation method and their physicochemical properties are characterized. It is shown that TOC-PLGA NPs are 110.8 nm, polydispersity index value of 0.042, and Zeta potential of -13.26 mV. The encapsulation efficiency and drug loading of NPs are 82.57% and 11.80%, respectively, and the cumulative release after 35 days of in vitro testing reaches 47%. Furthermore, TOC-PLGA NPs demonstrate a superior promotion effect on RAW 264.7 cell proliferation compared to PLGA NPs, being well phagocytosed and also promoting antigen uptake by macrophages. TOC-PLGA NPs can strongly upregulate the expression of co-stimulatory surface molecules and the secretion of cytokines. In conclusion, TOC-PLGA NPs can be a novel vaccine adjuvant with excellent biocompatibility and significant immune-enhancing activity.

Immunomodulatory effect of PLGA-encapsulated mesenchymal stem cells-derived exosomes for the treatment of allergic rhinitis

Introduction

Allergic rhinitis (AR) is an upper airway inflammatory disease of the nasal mucosa. Conventional treatments such as symptomatic pharmacotherapy and allergen-specific immunotherapy have considerable limitations and drawbacks. As an emerging therapy with regenerative potential and immunomodulatory effect, mesenchymal stem cell-derived exosomes (MSC-Exos) have recently been trialed for the treatment of various inflammatory and autoimmune diseases.

Methods

In order to achieve sustained and protected release of MSC-Exos for intranasal administration, we fabricated Poly(lactic-co-glycolic acid) (PLGA) micro and nanoparticles-encapsulated MSC-Exos (PLGA-Exos) using mechanical double emulsion for local treatment of AR. Preclinical in vivo imaging, ELISA, qPCR, flow cytometry, immunohistochemical staining, and multiomics sequencing were used for phenotypic and mechanistic evaluation of the therapeutic effect of PLGA-Exos in vitro and in vivo.

Results

The results showed that our PLGA platform could efficiently encapsulate and release the exosomes in a sustained manner. At protein level, PLGA-Exos treatment upregulated IL-2, IL-10 and IFN-γ, and downregulated IL-4, IL-17 and antigen-specific IgE in ovalbumin (OVA)-induced AR mice. At cellular level, exosomes treatment reduced Th2 cells, increased Tregs, and reestablished Th1/Th2 balance. At tissue level, PLGA-Exos significantly attenuated the infiltration of immune cells (e.g., eosinophils and goblet cells) in nasal mucosa. Finally, multiomics analysis discovered several signaling cascades, e.g., peroxisome proliferator-activated receptor (PPAR) pathway and glycolysis pathway, that might mechanistically support the immunomodulatory effect of PLGA-Exos.

Discussion

For the first time, we present a biomaterial-facilitated local delivery system for stem cell-derived exosomes as a novel and promising strategy for AR treatment.

Protective efficacy of Eimeria maxima EmLPL and EmTregIM-1 against homologous challenge in chickens

Chicken coccidiosis has inflicted significant economic losses upon the poultry industry. The primary strategies for preventing and controlling chicken coccidiosis include anticoccidial drugs and vaccination. However, these approaches face limitations, such as drug residues and resistance associated with anticoccidial drugs, and safety concerns related to live vaccines. Consequently, the urgent development of innovative vaccines, such as subunit vaccines, is imperative. In previous study, we screened 2 candidate antigens: Eimeria maxima lysophospholipase (EmLPL) and E. maxima regulatory T cell inducing molecule 1 (EmTregIM-1). To investigate the immune protective effect of the 2 candidate antigens against Eimeria maxima (E. maxima) infection, we constructed recombinant plasmids, namely pET-28a-EmLPL and pET-28a-EmTregIM-1, proceeded to induce the expression of recombinant proteins of EmLPL (rEmLPL) and EmTregIM-1 (rEmTregIM-1). The immunogenic properties of these proteins were confirmed through western blot analysis. Targeting EmLPL and EmTregIM-1, we developed subunit vaccines and encapsulated them in PLGA nanoparticles, resulting in nano-vaccines: PLGA-rEmLPL and PLGA-rEmTregIM-1. The efficacy of these vaccines was assessed through animal protection experiments. The results demonstrated that rEmLPL and rEmTregIM-1 were successfully recognized by anti-E. maxima chicken sera and His-conjugated mouse monoclonal antibodies. Immunization with both subunit and nano-vaccines containing EmLPL and EmTregIM-1 markedly mitigated weight loss and reduced oocyst shedding in chickens infected with E. maxima. Furthermore, the anticoccidial indexes (ACI) for both rEmLPL and PLGA-rEmLPL exceeded 160, whereas those for rEmTregIM-1 and PLGA-rEmTregIM-1 were above 120 but did not reach 160, indicating superior protective efficacy of the rEmLPL and PLGA-rEmLPL formulations. By contrast, the protection afforded by rEmTregIM-1 and PLGA-rEmTregIM-1 was comparatively lower. Thus, EmLPL is identified as a promising candidate antigen for vaccine development against E. maxima infection.

Polymeric Microneedles Enhance Transdermal Delivery of Therapeutics

This research presents the efficacy of polymeric microneedles in improving the transdermal permeation of methotrexate across human skin. These microneedles were fabricated from PLGA Expansorb® 50-2A and 50-8A and subjected to comprehensive characterization via scanning electron microscopy, Fourier-transform infrared spectroscopy, and mechanical analysis. We developed and assessed a methotrexate hydrogel for physicochemical and rheological properties. Dye binding, histological examinations, and assessments of skin integrity demonstrated the effective microporation of the skin by PLGA microneedles. We measured the dimensions of microchannels in the skin using scanning electron microscopy, pore uniformity analysis, and confocal microscopy. The skin permeation and disposition of methotrexate were researched in vitro. PLGA 50-8A microneedles appeared significantly longer, sharper, and more mechanically uniform than PLGA 50-2A needles. PLGA 50-8A needles generated substantially more microchannels, as well as deeper, larger, and more uniform channels in the skin than PLGA 50-2A needles. Microneedle insertion substantially reduced skin electrical resistance, accompanied by an elevation in transepidermal water loss values. PLGA 50-8A microneedle treatment provided a significantly higher cumulative delivery, flux, diffusion coefficient, permeability coefficient, and predicted steady-state plasma concentration; however, there was a shorter lag time than for PLGA 50-2A needles, base-treated, and untreated groups (p < 0.05). Conclusively, skin microporation using polymeric microneedles significantly improved the transdermal delivery of methotrexate.

Redox-Sensitive Poly(lactic-co-glycolic acid) Nanoparticles of Palbociclib: Development, Ultrasound/Photoacoustic Imaging, and Smart Breast Cancer Therapy

Breast cancer is one of the leading causes of mortality in women globally. The efficacy of breast cancer treatments, notably chemotherapy, is hampered by inadequate localized delivery of anticancer agents to the tumor site, resulting in compromised efficacy and increased systemic toxicity. In this study, we have developed redox-sensitive poly(lactic-co-glycolic acid) (PLGA) nanoparticles for the smart delivery of palbociclib (PLB) to breast cancer. The particle size of formulated PLB@PLGA-NPs (nonredox-sensitive) and RS-PLB@PLGA-NPs (redox-sensitive) NPs were 187.1 ± 1.8 nm and 193.7 ± 1.5 nm, respectively. The zeta potentials of nonredox-sensitive and redox-sensitive NPs were +24.99 ± 2.67 mV and +9.095 ± 1.87 mV, respectively. The developed NPs were characterized for morphological and various physicochemical parameters such as SEM, TEM, XRD, DSC, TGA, XPS, etc. The % entrapment efficiency of PLB@PLGA-NPs and RS-PLB@PLGA-NPs was found to be 85.48 ± 1.29% and 87.72 ± 1.55%, respectively. RS-PLB@PLGA-NPs displayed a rapid drug release at acidic pH and a higher GSH concentration compared to PLB@PLGA-NPs. The cytotoxicity assay in MCF-7 cells suggested that PLB@PLGA-NPs and RS-PLB@PLGA-NPs were 5.24-fold and 14.53-fold higher cytotoxic compared to the free PLB, respectively. Further, the cellular uptake study demonstrated that redox-sensitive NPs had significantly higher cellular uptake compared to nonredox-sensitive NPs and free Coumarin 6 dye. Additionally, AO/EtBr assay and reactive oxygen species analysis confirmed the superior activity of RS-PLB@PLGA-NPs over PLB@PLGA-NPs and free PLB. In vivo anticancer activity in dimethyl-benz(a)anthracene-induced breast cancer rats depicted that RS-PLB@PLGA-NPs was highly effective in reducing the tumor size, hypoxic tumor, and tumor vascularity compared to PLB@PLGA-NPs and free PLB. Further, hemocompatibility study reveals that the developed NPs were nonhemolytic to human blood. Moreover, an in vivo histopathology study confirmed that both nanoparticles were safe and nontoxic to the vital organs.

A dual-targeting therapeutic nanobubble for imaging-guided atherosclerosis treatment

Atherosclerosis is a cardiovascular disease that seriously endangers human health. Low shear stress (LSS) is recognized as a vital factor in causing chronic inflammatory and further inducing the occurrence and development of atherosclerosis. Targeting imaging and treatment are of substantial significance for the diagnosis and therapy of atherosclerosis. On this ground, a kind of ultrasound (US) imaging-guided therapeutic polymer nanobubbles (NBs) with dual targeting of magnetism and antibody was rationally designed and constructed for the efficiently treating LSS-mediated atherosclerosis. Under the combined targeting effect of an external magnetic field and antibodies, the drug-loaded therapeutic NBs can be effectively accumulated in the inflammatory area caused by LSS. Upon US irradiation, the NBs can be selectively disrupted, leading to the rapid release of the loaded drugs at the targeted site. Notably, the US irradiation generates a cavitation effect that induces repairable micro gaps in nearby cells, thereby enhancing the uptake of released drugs and further improving the therapeutic effect. The prominent US imaging, efficient anti-inflammatory effect and treatment outcome of LSS-mediated atherosclerosis had been verified in vivo on a surgically constructed LSS-atherosclerosis animal model. This work showcased the potential of the designed NBs with multifunctionality for in vivo imaging, dual-targeting, and drug delivery in the treatment of atherosclerosis.

Additive Manufacturing of Wet-Spun Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)-Based Scaffolds Loaded with Hydroxyapatite

Tissue engineering represents an advanced therapeutic approach for the treatment of bone tissue defects. Polyhydroxyalkanoates are a promising class of natural polymers in this context thanks to their biocompatibility, processing versatility, and mechanical properties. The aim of this study is the development by computer-aided wet-spinning of novel poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)-based composite scaffolds for bone engineering. In particular, PHBV scaffolds are loaded with hydroxyapatite (HA), an osteoinductive ceramic, in order to tailor their biological activity and mechanical properties. PHBV blending with poly(lactide-co-glycolide) (PLGA) is also explored to increase the processing properties of the polymeric mixture used for composite scaffold fabrication. Different HA percentages, up to 15% wt., can be loaded into the PHBV or PHBV/PLGA scaffolds without compromising their interconnected porous architecture, as well as the polymer morphological and thermal properties, as demonstrated by scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry. In addition, HA loading results in increased scaffold compressive stiffness to levels comparable to those of trabecular bone tissue, as well as in higher in vitro MC3T3-E1 cell viability and production of mineralized extracellular matrix, in comparison to what observed for unloaded scaffolds. The observed mechanical and biological properties suggest the suitability of the developed scaffolds for bone engineering.

Reversal of cisplatin resistance in oral squamous cell carcinoma by piperlongumine loaded smart nanoparticles through inhibition of Hippo-YAP signaling pathway

Cisplatin alone or in combination with 5FU and docetaxel is the preferred chemotherapy regimen for advanced-stage OSCC patients. However, its use has been linked to recurrence and metastasis due to the development of drug resistance. Therefore, sensitization of cancer cells to conventional chemotherapeutics can be an effective strategy to overcome drug resistance. Piperlongumine (PL), an alkaloid, have shown anticancer properties and sensitizes numerous neoplasms, but its effect on OSCC has not been explored. However, low aqueous solubility and poor pharmacokinetics limit its clinical application. Therefore, to improve its therapeutic efficacy, we developed piperlongumine-loaded PLGA-based smart nanoparticles (smart PL-NPs) that can rapidly release PL in an acidic environment of cancer cells and provide optimum drug concentrations to overcome chemoresistance. Our results revealed that smart PL-NPs has high cellular uptake in acidic environment, facilitating the intracellular delivery of PL and sensitizing cancer cells to cisplatin, resulting in synergistic anticancer activity in vitro by increasing DNA damage, apoptosis, and inhibiting drug efflux. Further, we have mechanistically explored the Hippo-YAP signaling pathway, which is the critical mediator of chemoresistance, and investigated the chemosensitizing effect of PL in OSCC. We observed that PL alone and in combination with cisplatin significantly inhibits the activation of YAP and its downstream target genes and proteins. In addition, the combination of cisplatin with smart PL-NPs significantly inhibited tumor growth in two preclinical models (patient-derived cell based nude mice and zebrafish xenograft). Taken together, our findings suggest that smart PL-NPs with cisplatin will be a novel formulation to reverse cisplatin resistance in patients with advanced OSCC.

Nano revolution in cardiovascular health: Nanoparticles (NPs) as tiny titans for diagnosis and therapeutics

Cardiovascular diseases (CVDs) are known as life-threatening illnessescaused by severe abnormalities in the cardiovascular system. They are a leading cause of mortality and morbidity worldwide.Nanotechnology integrated substantialinnovations in cardiovascular diagnostic and therapeutic at the nanoscale. This in-depth analysis explores cutting-edge methods for diagnosing CVDs, including nanotechnological interventions and crucial components for identifying risk factors, developing treatment plans, and monitoring patients' progress with chronic CVDs.Intensive research has gone into making nano-carriers that can image and treat patients. To improve the efficiency of treating CVDs, the presentreview sheds light on a decision-tree-based solution by investigating recent and innovative approaches in CVD diagnosis by utilizing nanoparticles (NPs). Treatment choices for chronic diseases like CVD, whose etiology might take decades to manifest, are very condition-specific and disease-stage-based. Moreover, thisreview alsobenchmarks the changing landscape of employing NPs for targeted and better drug administration while examining the limitations of various NPs in CVD diagnosis, including cost, space, time, and complexity. To better understand and treatment of cardiovascular diseases, the conversation moves on to the nano-cardiovascular possibilities for medical research.We also focus on recent developments in nanoparticle applications, the ways they might be helpful, and the medical fields where they may find future use. Finally, this reviewadds to the continuing conversation on improved diagnosis and treatment approaches for cardiovascular disorders by discussing the obstacles and highlighting the revolutionary effects of nanotechnology.

Swine influenza A virus: challenges and novel vaccine strategies

Swine Influenza A Virus (IAV-S) imposes a significant impact on the pork industry and has been deemed a significant threat to global public health due to its zoonotic potential. The most effective method of preventing IAV-S is vaccination. While there are tremendous efforts to control and prevent IAV-S in vulnerable swine populations, there are considerable challenges in developing a broadly protective vaccine against IAV-S. These challenges include the consistent diversification of IAV-S, increasing the strength and breadth of adaptive immune responses elicited by vaccination, interfering maternal antibody responses, and the induction of vaccine-associated enhanced respiratory disease after vaccination. Current vaccination strategies are often not updated frequently enough to address the continuously evolving nature of IAV-S, fail to induce broadly cross-reactive responses, are susceptible to interference, may enhance respiratory disease, and can be expensive to produce. Here, we review the challenges and current status of universal IAV-S vaccine research. We also detail the current standard of licensed vaccines and their limitations in the field. Finally, we review recently described novel vaccines and vaccine platforms that may improve upon current methods of IAV-S control.

From Polymeric Nanoformulations to Polyphenols-Strategies for Enhancing the Efficacy and Drug Delivery of Gentamicin

Gentamicin is an essential broad-spectrum aminoglycoside antibiotic that is used in over 40 clinical conditions and has shown activity against a wide range of nosocomial, biofilm-forming, multi-drug resistant bacteria. Nevertheless, the low cellular penetration and serious side effects of gentamicin, as well as the fear of the development of antibacterial resistance, has led to a search for ways to circumvent these obstacles. This review provides an overview of the chemical and pharmacological properties of gentamicin and offers six different strategies (the isolation of specific types of gentamicin, encapsulation in polymeric nanoparticles, hydrophobization of the gentamicin molecule, and combinations of gentamicin with other antibiotics, polyphenols, and natural products) that aim to enhance the drug delivery and antibacterial activity of gentamicin. In addition, factors influencing the synthesis of gentamicin-loaded polymeric (poly (lactic-co-glycolic acid) (PLGA) and chitosan) nanoparticles and the methods used in drug release studies are discussed. Potential research directions and future perspectives for gentamicin-loaded drug delivery systems are given.

Minocycline-loaded nHAP/PLGA microspheres for prevention of injury-related corneal angiogenesis

BACKGROUND

Corneal neovascularization (CoNV) threatens vision by disrupting corneal avascularity, however, current treatments, including pharmacotherapy and surgery, are hindered by limitations in efficacy and adverse effects. Minocycline, known for its anti-inflammatory properties, could suppress CoNV but faces challenges in effective delivery due to the cornea's unique structure. Therefore, in this study a novel drug delivery system using minocycline-loaded nano-hydroxyapatite/poly (lactic-co-glycolic acid) (nHAP/PLGA) nanoparticles was developed to improve treatment outcomes for CoNV.

RESULTS

Ultra-small nHAP was synthesized using high gravity technology, then encapsulated in PLGA by a double emulsion method to form nHAP/PLGA microspheres, attenuating the acidic by-products of PLGA degradation. The MINO@PLGA nanocomplex, featuring sustained release and permeation properties, demonstrated an efficient delivery system for minocycline that significantly inhibited the CoNV area in an alkali-burn model without exhibiting apparent cytotoxicity. On day 14, the in vivo microscope examination and ex vivo CD31 staining corroborated the inhibition of neovascularization, with the significantly smaller CoNV area (29.40% ± 6.55%) in the MINO@PLGA Tid group (three times daily) than that of the control group (86.81% ± 15.71%), the MINO group (72.42% ± 30.15%), and the PLGA group (86.87% ± 14.94%) (p < 0.05). Fluorescein sodium staining show MINO@PLGA treatments, administered once daily (Qd) and three times daily (Tid) demonstrated rapid corneal epithelial healing while the Alkali injury group and the DEX group showed longer healing times (p < 0.05). Additionally, compared to the control group, treatments with dexamethasone, MINO, and MINO@PLGA were associated with an increased expression of TGF-β as evidenced by immunofluorescence, while the levels of pro-inflammatory cytokines IL-1β and TNF-α demonstrated a significant decrease following alkali burn. Safety evaluations, including assessments of renal and hepatic biomarkers, along with H&E staining of major organs, revealed no significant cytotoxicity of the MINO@PLGA nanocomplex in vivo.

CONCLUSIONS

The novel MINO@PLGA nanocomplex, comprising minocycline-loaded nHAP/PLGA microspheres, has shown a substantial capacity for preventing CoNV. This study confirms the complex's ability to downregulate inflammatory pathways, significantly reducing CoNV with minimal cytotoxicity and high biosafety in vivo. Given these findings, MINO@PLGA stands as a highly promising candidate for ocular conditions characterized by CoNV.

Recent development and future application of biodegradable ureteral stents

Ureteral stenting is a common clinical procedure for the treatment of upper urinary tract disorders, including conditions such as urinary tract infections, tumors, stones, and inflammation. Maintaining normal renal function by preventing and treating ureteral obstruction is the primary goal of this procedure. However, the use of ureteral stents is associated with adverse effects, including surface crusting, bacterial adhesion, and lower urinary tract symptoms (LUTS) after implantation. Recognizing the need to reduce the complications associated with permanent ureteral stent placement, there is a growing interest among both physicians and patients in the use of biodegradable ureteral stents (BUS). The evolution of stent materials and the exploration of different stent coatings have given these devices different roles tailored to different clinical needs, including anticolithic, antibacterial, antitumor, antinociceptive, and others. This review examines recent advances in BUS within the last 5 years, providing an in-depth analysis of their characteristics and performance. In addition, we present prospective insights into the future applications of BUS in clinical settings.

Neural stem cell therapies for spinal cord injury repair: an update on recent preclinical and clinical advances

Traumatic spinal cord injury (SCI) is a leading cause of lifelong disabilities. Permanent sensory, motor and autonomic impairments after SCI are substantially attributed to degeneration of spinal cord neurons and axons, and disintegration of neural network. To date, minimal regenerative treatments are available for SCI with an unmet need for new therapies to reconstruct the damaged spinal cord neuron-glia network and restore connectivity with the supraspinal pathways. Multipotent neural precursor cells (NPCs) have a unique capacity to generate neurons, oligodendrocytes and astrocytes. Due to this capacity, NPCs have been an attractive cell source for cellular therapies for SCI. Transplantation of NPCs has been extensively tested in preclinical models of SCI in the past two decades. These studies have identified opportunities and challenges associated with NPC therapies. While NPCs have the potential to promote neuroregeneration through various mechanisms, their low long-term survival and integration within the host injured spinal cord limit the functional benefits of NPC-based therapies for SCI. To address this challenge, combinatorial strategies have been developed to optimize the outcomes of NPC therapies by enriching SCI microenvironment through biomaterials, genetic and pharmacological therapies. In this review, we will provide an in-depth discussion on recent advances in preclinical NPC-based therapies for SCI. We will discuss modes of actions and mechanism by which engrafted NPCs contribute to the repair process and functional recovery. We will also provide an update on current clinical trials and new technologies that have facilitated preparation of medical-grade human NPCs suitable for transplantation in clinical studies.

Tuberculosis vaccine developments and efficient delivery systems: A comprehensive appraisal

Despite the widespread use of the Bacillus Calmette-Guérin (BCG) vaccine, Mycobacterium tuberculosis (MTB) continues to be a global burden. Vaccination has been proposed to prevent and treat tuberculosis (TB) infection, and several of them are in different phases of clinical trials. Though vaccine production is in progress but requires more attention. There are several TB vaccines in the trial phase, most of which are based on a combination of proteins/adjuvants or recombinant viral vectors used for selected MTB antigens. In this review, we attempted to discuss different types of TB vaccines based on the vaccine composition, the immune responses generated, and their clinical trial phases. Furthermore, we have briefly overviewed the effective delivery systems used for the TB vaccine and their effectiveness in different vaccines.

Polymeric DNase-I nanozymes targeting neutrophil extracellular traps for the treatment of bowel inflammation

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a family of chronic disorders along the gastrointestinal tract. Because of its idiopathic nature, IBD does not have a fundamental cure; current available therapies for IBD are limited to prolonged doses of immunomodulatory agents. While these treatments may reduce inflammation, limited therapeutic efficacy, inconsistency across patients, and adverse side effects from aggressive medications remain as major drawbacks. Recently, excessive production and accumulation of neutrophil extracellular traps (NETs) also known as NETosis have been identified to exacerbate inflammatory responses and induce further tissue damage in IBD. Such discovery invited many researchers to investigate NETs as a potential therapeutic target. DNase-I is a natural agent that can effectively destroy NETs and, therefore, potentially reduce NETs-induced inflammations even without the use of aggressive drugs. However, low stability and rapid clearance of DNase-I remain as major limitations for further therapeutic applications. In this research, polymeric nanozymes were fabricated to increase the delivery and therapeutic efficacy of DNase-I. DNase-I was immobilized on the surface of polymeric nanoparticles to maintain its enzymatic properties while extending its activity in the colon. Delivery of DNase-I using this platform allowed enhanced stability and prolonged activity of DNase-I with minimal toxicity. When administered to animal models of IBD, DNase-I nanozymes successfully alleviated various pathophysiological symptoms of IBD. More importantly, DNase-I nanozyme administration successfully attenuated neutrophil infiltration and NETosis in the colon compared to free DNase-I or mesalamine.

A Review of the Potential of Poly-(lactide-co-glycolide) Nanoparticles as a Delivery System for an Active Antimycobacterial Compound, 7-Methyljuglone

7-Methyljuglone (7-MJ) is a pure compound isolated from the roots of Euclea natalensis A. DC., a shrub indigenous to South Africa. It exhibits significant promise as a potential treatment for the highly communicable disease tuberculosis (TB), owing to its effective antimycobacterial activity against Mycobacterium tuberculosis. Despite its potential therapeutic benefits, 7-MJ has demonstrated in vitro cytotoxicity against various cancerous and non-cancerous cell lines, raising concerns about its safety for consumption by TB patients. Therefore, this review focuses on exploring the potential of poly-(lactide-co-glycolic) acid (PLGA) nanoparticles as a delivery system, which has been shown to decrease in vitro cytotoxicity, and 7-MJ as an effective antimycobacterial compound.

Functionalisation of lignin with urethane linkages and their strengthening effect on PLA composites

Lignin was functionalised by crosslinking with hexamethylene diisocyanate (HDI) through the heterogenous reaction in the solvent dimethyl sulfoxide for preferential improvement in the mechanical properties of composites. The successful synthesis of lignin modified with HDI was confirmed by the instrumental analyses, e.g., FTIR, XPS, and FESEM. The incorporation of optimum crosslinked lignin in polylactic acid (PLA) matrix was systematically evaluated on the basis of their thermal stability, mechanical property, glass transition temperature (Tg), water contact angle, water absorption, and water permeability. The results displayed that incorporation of fillers had prominent effects on tensile tear strength, which could improve tensile strength up to 231 % and elongation at break up to 53 % due to the good interface compatibility between PLA and modified lignin. Further, with the inclusion of fillers, PLA composites exhibited higher crystallinity in comparison to neat PLA.

Multifunctional role of nanoparticles for the diagnosis and therapeutics of cardiovascular diseases

The increasing burden of cardiovascular disease (CVD) remains responsible for morbidity and mortality worldwide; their effective diagnostic or treatment methods are of great interest to researchers. The use of NPs and nanocarriers in cardiology has drawn much interest. The present comprehensive review provides deep insights into the use of current and innovative approaches in CVD diagnostics to offer practical ways to utilize nanotechnological interventions and the critical elements in the CVD diagnosis, associated risk factors, and management strategies of patients with chronic CVDs. We proposed a decision tree-based solution by discussing the emerging applications of NPs for the higher number of rules to increase efficiency in treating CVDs. This review-based study explores the screening methods, tests, and toxicity to provide a unique way of creating a multi-parametric feature that includes cutting-edge techniques for identifying cardiovascular problems and their treatments. We discussed the benefits and drawbacks of various NPs in the context of cost, space, time and complexity that have been previously suggested in the literature for the diagnosis of CVDs risk factors. Also, we highlighted the advances in using NPs for targeted and improved drug delivery and discussed the evolution toward the nano-cardiovascular potential for medical science. Finally, we also examined the mixed-based diagnostic approaches crucial for treating cardiovascular disorders, broad applications and the potential future applications of nanotechnology in medical sciences.

Novel Discoveries and Clinical Advancements for Treating Onychomycosis: A Mechanistic Insight

Onychomycosis continues to be the most challenging disease condition for pharmaceutical scientists to develop an effective drug delivery system. Treatment challenges lie in incomplete cure and high relapse rate. Present compilation provides cumulative information on pathophysiology, diagnostic techniques, and conventional treatment strategies to manage onychomycosis. Novel technologies developed for successful delivery of antifungal molecules are also discussed in brief. Multidirectional information offered by this article also unlocks the panoramic view of leading patented technologies and clinical trials. The obtained clinical landscape recommends the use of advanced technology driven approaches, as a promising way-out for treatment of onychomycosis. Collectively, present review warrants the application of novel technologies for the successful management of onychomycosis. This review will assist readers to envision a better understanding about the technologies available for combating onychomycosis. We also trust that these contributions address and certainly will encourage the design and development of nanocarriers-based delivery vehicles for effective management of onychomycosis.

Surface Modification Progress for PLGA-Based Cell Scaffolds

Poly(lactic-glycolic acid) (PLGA) is a biocompatible bio-scaffold material, but its own hydrophobic and electrically neutral surface limits its application as a cell scaffold. Polymer materials, mimics ECM materials, and organic material have often been used as coating materials for PLGA cell scaffolds to improve the poor cell adhesion of PLGA and enhance tissue adaptation. These coating materials can be modified on the PLGA surface via simple physical or chemical methods, and coating multiple materials can simultaneously confer different functions to the PLGA scaffold; not only does this ensure stronger cell adhesion but it also modulates cell behavior and function. This approach to coating could facilitate the production of more PLGA-based cell scaffolds. This review focuses on the PLGA surface-modified materials, methods, and applications, and will provide guidance for PLGA surface modification.

Melt Processing Virus-Like Particle-Based Vaccine Candidates into Biodegradable Polymer Implants

Melt processing is an emerging production method to efficiently encapsulate proteins into polymeric devices for sustained release. In the context of vaccines, melt processing is well-suited to develop vaccine delivery devices that are stable outside the cold chain and can generate protective immunity from a single dose. We have demonstrated the compatibility of bacteriophage Qβ virus-like particles (VLPs) with hot-melt extrusion (HME) and have leveraged this technology to develop a single-dose vaccine candidate for vaccination against human papillomavirus (HPV). Here, we detail the methods for chemically conjugating an HPV peptide epitope from the L2 minor capsid protein to Qβ VLPs to generate HPV-Qβ particles. We outline techniques used to characterize HPV-Qβ particles, and we elaborate on the process to encapsulate HPV-Qβ into biodegradable poly(lactic-co-glycolic acid) (PLGA) implants and discuss methods for the materials characterization of the HPV-Qβ/polymer melts. The methods described could be adapted to other disease targets, i.e., by conjugation of a different peptide epitope, or transferred to other VLP systems suited for conjugation, immune response, or stability during processing. Such VLPs are ideally suited for use in HME, a mature, scalable, continuous, and solvent-free process which can be adapted to mold devices, therefore allowing the processing of the melts into various geometries, such as subcutaneous implants, or self-administrable microneedle patches.

Targeted Treatment Strategies for Mitochondria Dysfunction: Correlation with Neurological Disorders

Mitochondria are an essential intracellular organelle for medication targeting and delivery since they seem to create energy and conduct many other cellular tasks, and mitochondrial dysfunctions and malfunctions lead to many illnesses. Many initiatives have been taken to detect, diagnose, and image mitochondrial abnormalities, and to transport and accumulate medicines precisely to mitochondria, all because of special mitochondrial aspects of the pathophysiology of cancer. In addition to the negative membrane potential and paradoxical mitochondrial dynamics, they include high temperatures, high levels of reactive oxygen species, high levels of glutathione, and high temperatures. Neurodegenerative diseases represent a broad spectrum of debilitating illnesses. They are linked to the loss of certain groups of neurons based on an individual's physiology or anatomy. The mitochondria in a cell are generally accepted as the authority with respect to ATP production. Disruption of this system is linked to several cellular physiological issues. The development of neurodegenerative disorders has been linked to mitochondrial malfunction, according to pathophysiological studies. There seems to be substantial evidence connecting mitochondrial dysfunction and oxidative stress to the development of neurodegenerative disorders. It has been extensively observed that mitochondrial malfunction triggers autophagy, which plays a role in neurodegenerative disorders. In addition, excitotoxicity and mitochondrial dysfunction have been linked to the development of neurodegenerative disorders. The pathophysiology of neurodegenerative illnesses has been linked to increased apoptosis and necrosis, as well as mitochondrial malfunction. A variety of synthetic and natural treatments have shown efficacy in treating neurodegenerative illnesses caused by mitochondrial failure. Neurodegenerative illnesses can be effectively treated with existing drugs that target mitochondria, although their precise formulations are poorly understood. Therefore, there is an immediate need to focus on creating drug delivery methods specifically targeted at mitochondria in the treatment and diagnosis of neurodegenerative disorders.

Bringing pathology to nanomedicine: a comparison of in vivo toxicity of polymeric nanoparticle carriers with and without chitosan coating

Over the last years, there has been an increasing number of proposals for the use of nanomaterials in medicine. The safety of novel technologies must be verified, prior to their clinical application. Pathology has much to contribute towards this end. In this study, we compared the in vivo toxicity effects of poly- (lactic-co-glycolic acid) nanoparticles with and without chitosan shell. Both nanoparticle types were loaded with curcumin. The nanoparticles were assessed in vitro for potential cytotoxicity with cell viability studies. For the in vivo test, 36 adult Wistar rats were used, four of which were the control group. The remaining 32 were divided into 2 groups, each of which was administered differentially coated drug carriers: (A) nanoparticles without chitosan coating and (B) nanoparticles with chitosan coating. For both groups, the subcutaneous route was used for administration. Each group was further divided into 2 sub-groups of 8 animals each. The animals of the first sub-groups were sacrificed 24 h after the injection and those of the second on the 7th day. The control group was also divided into 2 subgroups of 2 animals each. At the appointed post-administrative date, the rats were sacrificed, and specimens from the brain, liver, kidneys, heart, stomach, lungs, and from the skin at the injection site were collected and studied histopathologically. The evaluation of both in vitro and in vivo testing shows that nanoparticles with chitosan have significantly less, if any, toxic effects compared to those without chitosan.

Recent advances in nano- and micro-scale carrier systems for controlled delivery of vaccines

Vaccines provide substantial safety against infectious diseases, saving millions of lives each year. The recent COVID-19 pandemic highlighted the importance of vaccination in providing mass-scale immunization against outbreaks. However, the delivery of vaccines imposes a unique set of challenges due to their large molecular size and low room temperature stability. Advanced biomaterials and delivery systems such as nano- and mciro-scale carriers are becoming critical components for successful vaccine development. In this review, we provide an updated overview of recent advances in the development of nano- and micro-scale carriers for controlled delivery of vaccines, focusing on carriers compatible with nucleic acid-based vaccines and therapeutics that emerged amid the recent pandemic. We start by detailing nano-scale delivery systems, focusing on nanoparticles, then move on to microscale systems including hydrogels, microparticles, and 3D printed microneedle patches. Additionally, we delve into emerging methods that move beyond traditional needle-based applications utilizing innovative delivery systems. Future challenges for clinical translation and manufacturing in this rapidly advancing field are also discussed.

Recent Developments in Metallic Degradable Micromotors for Biomedical and Environmental Remediation Applications

Synthetic micromotor has gained substantial attention in biomedicine and environmental remediation. Metal-based degradable micromotor composed of magnesium (Mg), zinc (Zn), and iron (Fe) have promise due to their nontoxic fuel-free propulsion, favorable biocompatibility, and safe excretion of degradation products Recent advances in degradable metallic micromotor have shown their fast movement in complex biological media, efficient cargo delivery and favorable biocompatibility. A noteworthy number of degradable metal-based micromotors employ bubble propulsion, utilizing water as fuel to generate hydrogen bubbles. This novel feature has projected degradable metallic micromotors for active in vivo drug delivery applications. In addition, understanding the degradation mechanism of these micromotors is also a key parameter for their design and performance. Its propulsion efficiency and life span govern the overall performance of a degradable metallic micromotor. Here we review the design and recent advancements of metallic degradable micromotors. Furthermore, we describe the controlled degradation, efficient in vivo drug delivery, and built-in acid neutralization capabilities of degradable micromotors with versatile biomedical applications. Moreover, we discuss micromotors' efficacy in detecting and destroying environmental pollutants. Finally, we address the limitations and future research directions of degradable metallic micromotors.

Reduction-responsive polymeric micelles for trans-corneal targeted delivery of microRNA-21-5p and glaucoma-specific gene therapy

The therapeutic value of microRNA (miRNA) for the treatment of glaucoma has become a focus of attention. However, naked miRNA cannot cross the corneal barrier and reach the target tissue by itself. Thus, the precise transport of miRNA to the target sites is key to the success of gene therapy. Herein, we selected a miRNA, namely miR-21-5p, based on its unique intraocular pressure (IOP) mechano-sensing property. Moreover, a biocompatible polymeric poly(L-lysine) (PLL) micelle conjugated with collagenase and ABCA1 antibody was judiciously constructed to achieve the trans-corneal and target delivery of miR-21-5p to the trabecular meshwork (TM) and Schlemm's canal (SC) tissues inside the eye. The topically administrated PLL micelles as an eye drop successfully crossed the cornea with the help of collagenase and then preferentially accumulated in the target TM/SC tissues under the guidance of the ABCA1 antibody. When endocytosed by TM/SC cells, the PLL micelles could be decomposed in the reductive lysosomal environment to release miR-21-5p for successfully lowering the IOP by activating the miR-21-5p/eNOS/MMP9 signaling axis, which will open new prospects for glaucoma-specific gene therapy.

Influence of drug molecular weight on self-assembly and intestinal permeation of polymer-based nanocarriers

For oral delivery, the physicochemical properties of nanocarriers are decisive factors for permeation through the intestinal epithelium. These properties are determined by the composition of the nanocarriers as well as by the process parameters during their self-assembly. For macromolecular drugs, there is still little understanding of the drug-polymer interactions during nanocarrier self-assembly and the effects on carrier properties. In this study, the effect of drug molecular weight on nanocarrier self-assembly, physicochemical properties of nanocarriers as well as their permeation across the intestinal epithelium was investigated. Our results show that the drug molecular weight impacts the physicochemical properties of nanocarriers. Further, the physicochemical properties of the nanocarriers, governed by the molecular weight of the drug, determine their permeation properties across the intestinal epithelium. Comparative in vitro and ex vivo studies revealed that intestinal absorption is dependent on both, the properties of the tissue as well as properties of the carrier system. In conclusion, the molecular weight of drug payload is a key factor determining the physiochemical properties of polymeric nanocarriers and is closely linked to their oral absorption. Using different preclinical models to evaluate intestinal permeation of nanocarriers allows for novel insights into key formulation properties governing oral bioavailability.

Optimization of PLGA-DSPE hybrid nano-micelles with enhanced hydrophobic capacity for curcumin delivery

Poly (D, L Lactic-co-Glycolic acid) (PLGA) is an FDA-approved polymer. It is distinguished from other biocompatible polymers by its feasibility of production and safety for intravenous cancer tumor targeting. Curcumin (CUR) is a natural molecule with versatile bioactivities including inhibiting the nuclear Factor kappa B (Nf-kB) levels in cancer cells, increased by chemotherapy agents. Our group previously reported a successful decrease in the p65 (RelA) subunit of Nf-kB using 125 µg/ml CUR loaded into PLGA nano-micelles. However, this amount was insufficient to reduce all Nf-kB subunits. This study aimed to increase the hydrophobic capacity of PLGA toward CUR using 1,2-Distearoyl-sn-glycerol-3-phosphoethanolamine (DSPE), an FDA-approved phospholipid. PLGA-DSPE hybrid nano-micelles (HNM) were prepared using two different methods, oil-in-water (OiWa) and film preparation-rehydration (FiRe). The encapsulated CUR was successfully increased to 250 µg/ml using the FiRe method. Physicochemical characterization of CUR-loaded HNM was performed using DLS FT-IR, DSC, and HPLC. In HNM with a size of 156.6 nm, DSPE, incorporated with all functional groups of PLGA, and CUR was trapped in the core of this structure. The release profile of CUR was suitable for targeted cancer therapy and the Encapsulation Efficacy was 92%.

Porous biomaterial scaffolds for skeletal muscle tissue engineering

Volumetric muscle loss is a traumatic injury which overwhelms the innate repair mechanisms of skeletal muscle and results in significant loss of muscle functionality. Tissue engineering seeks to regenerate these injuries through implantation of biomaterial scaffolds to encourage endogenous tissue formation and to restore mechanical function. Many types of scaffolds are currently being researched for this purpose. Scaffolds are typically made from either natural, synthetic, or conductive polymers, or any combination therein. A major criterion for the use of scaffolds for skeletal muscle is their porosity, which is essential for myoblast infiltration and myofiber ingrowth. In this review, we summarize the various methods of fabricating porous biomaterial scaffolds for skeletal muscle regeneration, as well as the various types of materials used to make these scaffolds. We provide guidelines for the fabrication of scaffolds based on functional requirements of skeletal muscle tissue, and discuss the general state of the field for skeletal muscle tissue engineering.

Recent Advances in Anti-Atherosclerosis and Potential Therapeutic Targets for Nanomaterial-Derived Drug Formulations

Atherosclerosis, the leading cause of death worldwide, is responsible for ≈17.6 million deaths globally each year. Most therapeutic drugs for atherosclerosis have low delivery efficiencies and significant side effects, and this has hampered the development of effective treatment strategies. Diversified nanomaterials can improve drug properties and are considered to be key for the development of improved treatment strategies for atherosclerosis. The pathological mechanisms underlying atherosclerosis is summarized, rationally designed nanoparticle-mediated therapeutic strategies, and potential future therapeutic targets for nanodelivery. The content of this study reveals the potential and challenges of nanoparticle use for the treatment of atherosclerosis and highlights new effective design ideas.

Degradation behavior of 2D auxetic structure with biodegradable polymer under mechanical stress

Coronary heart disease is serious harm to human health. Vascular scaffold implantation is the main treatment. Biodegradable polymers are widely used in vascular scaffolds for good biodegradability and biocompatibility. However, whether the mechanical properties and radial expansion ability can successfully implant the scaffold without acute elastic retraction remains to be further studied. Because of the unique deformation mechanism, shear resistance, and resilience, auxetic structures can effectively avoid the restenosis of degraded vascular scaffolds. Firstly, the plane isotropic and plane anisotropic auxetic structural scaffolds were designed. The control structures (traditional structures) scaffolds were taken as the contrast. PCL was used to prepare the vascular auxetic by 3D printing. The printing parameters of fused deposition 3D printing, such as printing temperature, printing speed, and printing pressure, were studied to determine the optimal printing parameters of PCL. A self-assembled cyclic tensile stress loading device was used to investigate the degradation behavior of different scaffolds under different sizes of cyclic tensile stress, such as surface morphology, pH changes, mass loss rate, and mechanical properties. The increase of stress, surface roughness, and mass loss rate of the scaffolds all showed an increasing trend. pH gradually decreased from the fifth week, and the decrease was proportional to the stress. A large level of stress loading intensifies the decline of elastic modulus and the ultimate strength of the scaffold. In conclusion, the increase of periodic tensile stress will accelerate the degradation of scaffolds, and the degradation behavior of scaffolds with different configurations is different. The degradation rate of dilatant scaffolds was higher than that of control scaffolds, and the degradation rate of anisotropic auxetic scaffolds was higher than that of isotropic auxetic scaffolds, which provides a theoretical reference for the application of auxetic structure in the degradation of vascular scaffolds.

The Recent Applications of PLGA-Based Nanostructures for Ischemic Stroke

With the accelerated development of nanotechnology in recent years, nanomaterials have become increasingly prevalent in the medical field. The poly (lactic acid-glycolic acid) copolymer (PLGA) is one of the most commonly used biodegradable polymers. It is biocompatible and can be fabricated into various nanostructures, depending on requirements. Ischemic stroke is a common, disabling, and fatal illness that burdens society. There is a need for further improvement in the diagnosis and treatment of this disease. PLGA-based nanostructures can facilitate therapeutic compounds' passage through the physicochemical barrier. They further provide both sustained and controlled release of therapeutic compounds when loaded with drugs for the treatment of ischemic stroke. The clinical significance and potential of PLGA-based nanostructures can also be seen in their applications in cell transplantation and imaging diagnostics of ischemic stroke. This paper summarizes the synthesis and properties of PLGA and reviews in detail the recent applications of PLGA-based nanostructures for drug delivery, disease therapy, cell transplantation, and the imaging diagnosis of ischemic stroke.

Development of ionic liquid-coated PLGA nanoparticles for applications in intravenous drug delivery

Polymeric nanoparticles (NPs) are a promising platform for medical applications in drug delivery. However, their use as drug carriers is limited by biological (e.g., immunological) barriers after intravenous administration. Ionic liquids (ILs), formed from bulky asymmetric cations and anions, have a wide variety of physical internal and external interfacing properties. When assembled on polymeric NPs as biomaterial coatings, these external-interfacing properties can be tuned to extend their circulation half-life when intravenously injected, as well as drive biodistribution to sites of interest for selective organ accumulation. In our work, we are particularly interested in optimizing IL coatings to enable red blood cell hitchhiking in whole blood. In this protocol, we describe the preparation and physicochemical and biological characterization of choline carboxylate IL-coated polymeric NPs. The procedure is divided into five stages: (1) synthesis and characterization of choline-based ILs (1 week); (2) bare poly(lactic-co-glycolic acid) (50:50, acid terminated) Resomer 504H (PLGA) NP assembly, modified from previously established protocols, with dye encapsulation (7 h); (3) modification of the bare particles with IL coating (3 h); (4) physicochemical characterization of both PLGA and IL-PLGA NPs by dynamic light scattering, 1H nuclear magnetic resonance spectroscopy, and transmission electron microscopy (1 week); (5) ex vivo evaluation of intravenous biocompatibility (including serum-protein resistance and hemolysis) and red blood cell hitchhiking in whole BALB/c mouse blood via fluorescence-activated cell sorting (1 week). With practice and technique refinement, this protocol is accessible to late-stage graduate students and early-stage postdoctoral scientists.

PEI-PLGA nanoparticles significantly enhanced the immunogenicity of IsdB137-361 proteins from Staphylococcus aureus

INTRODUCTION

Staphylococcus aureus seriously threatens human and animal health. IsdB137-361 of the iron surface determinant B protein (IsdB) from S. aureus exhibits the strong immunogenicity, but its immunoprotective effect is still to be further promoted. Because PEI-PLGA nanoparticles are generated by PEI conjugate with PLGA to develop great potential as a novel immune adjuvant, the immunogenicity of IsdB137-361 is likely be strengthened by PEI-PLGA.

METHODS

Here, PEI-PLGA nanoparticles containing IsdB137-361 proteins were prepared by optimizing the entrapment efficiency. Mice were immunized with IsdB137-361 -PEI-PLGA nanoparticles to assess their anti-S. aureus effects. The level of IFN-γ, IL-4, IL-17, and IL-10 cytokines from spleen lymphocytes in mice and generation of the antibodies against IsdB137-361 in serum was assessed by ELISA, the protective immune response was appraised by S. aureus challenge.

RESULTS

IsdB137-361 proteins loaded by PEI-PLGA were able to stimulate effectively the proliferation of spleen lymphocytes and increase the secretion of IFN-γ, IL-4, IL-17, and IL-10 cytokine from spleen lymphocytes, and significantly enhance generation of the antibodies against IsdB137-361 in serum, reduce the level of bacterial load in liver, spleen and kidney, and greatly improve the survival rate of mice after challenge.

CONCLUSION

These data showed that PEI-PLGA nanoparticles can significantly enhance the immunogenicity of IsdB137-361 proteins, and provide an important reference for the development of novel immune adjuvant.

Cinnamaldehyde Loaded Poly(lactide-co-glycolide) (PLGA) Microparticles for Antifungal Delivery Application against Resistant Candida albicans and Candida glabrata

Researchers have explored natural products to combat the antibiotic resistance of various microorganisms. Cinnamaldehyde (CIN), a major component of cinnamon essential oil (CC-EO), has been found to effectively inhibit the growth of bacteria, fungi, and mildew, as well as their production of toxins. Therefore, this study aimed to create a delivery system for CIN using PLGA microparticles (CIN-MPs), and to compare the antifungal activity of the carried and free CIN, particularly against antibiotic-resistant strains of Candida spp. The first part of the study focused on synthesizing and characterizing the PLGA MPs, which had no toxic effects in vivo and produced results in line with the existing literature. The subsequent experiments analyzed the antifungal effects of MPs-CIN on Candida albicans and Candida glabrata, both resistant (R) and sensitive (S) strains and compared its efficacy with the conventional addition of free CIN to the culture medium. The results indicated that conveyed CIN increased the antifungal effects of the product, particularly towards C. albicans R. The slow and prolonged release of CIN from the PLGA MPs ensured a constant and uniform concentration of the active principle within the cells.

Polymer-based drug delivery systems under investigation for enzyme replacement and other therapies of lysosomal storage disorders

Lysosomes play a central role in cellular homeostasis and alterations in this compartment associate with many diseases. The most studied example is that of lysosomal storage disorders (LSDs), a group of 60 + maladies due to genetic mutations affecting lysosomal components, mostly enzymes. This leads to aberrant intracellular storage of macromolecules, altering normal cell function and causing multiorgan syndromes, often fatal within the first years of life. Several treatment modalities are available for a dozen LSDs, mostly consisting of enzyme replacement therapy (ERT) strategies. Yet, poor biodistribution to main targets such as the central nervous system, musculoskeletal tissue, and others, as well as generation of blocking antibodies and adverse effects hinder effective LSD treatment. Drug delivery systems are being studied to surmount these obstacles, including polymeric constructs and nanoparticles that constitute the focus of this article. We provide an overview of the formulations being tested, the diseases they aim to treat, and the results observed from respective in vitro and in vivo studies. We also discuss the advantages and disadvantages of these strategies, the remaining gaps of knowledge regarding their performance, and important items to consider for their clinical translation. Overall, polymeric nanoconstructs hold considerable promise to advance treatment for LSDs.

Long-acting PLGA microspheres: advances in excipient and product analysis toward improved product understanding

Poly(lactic-co-glycolic acid) (PLGA) microspheres are a sustained-release drug delivery system with several successful commercial products used for the treatment of a variety of diseases. By utilizing PLGA polymers with different compositions, therapeutic agents can be released over durations varying from several weeks to several months. However, precise quality control of PLGA polymers and a fundamental understanding of all the factors associated with the performance of PLGA microsphere formulations remains challenging. This knowledge gap can hinder product development of both innovator and generic products. In this review, variability of the key release controlling excipient (PLGA), as well as advanced physicochemical characterization techniques for the PLGA polymer and PLGA microspheres are discussed. The relative merits and challenges of different in vitro release testing methods, in vivo pharmacokinetic studies, and in vitro-in vivo correlation development are also summarized. This review is intended to provide an in-depth understanding of long-acting microsphere products and consequently facilitate the development of these complex products.

Cargo-free particles divert neutrophil-platelet aggregates to reduce thromboinflammation

The combination of inflammation and thrombosis is a hallmark of many cardiovascular diseases. Under such conditions, platelets are recruited to an area of inflammation by forming platelet-leukocyte aggregates via interaction of PSGL-1 on leukocytes and P-selectin on activated platelets, which can bind to the endothelium. While particulate drug carriers have been utilized to passively redirect leukocytes from areas of inflammation, the downstream impact of these carriers on platelet accumulation in thromboinflammatory conditions has yet to be studied. Here, we explore the ability of polymeric particles to divert platelets away from inflamed blood vessels both in vitro and in vivo. We find that untargeted and targeted micron-sized polymeric particles can successfully reduce platelet adhesion to an inflamed endothelial monolayer in vitro in blood flow systems and in vivo in a lipopolysaccharide-induced, systemic inflammation murine model. Our data represent initial work in developing cargo-free, anti-platelet therapeutics specifically for conditions of thromboinflammation.