Polymer degradation and drug delivery in PLGA-based drug-polymer applications: A review of experiments and theories

Biomaterial-mediated intracellular control of macrophages for cell therapy in pro-inflammatory and pro-fibrotic conditions

Macrophages are key modulators of all inflammatory diseases and essential for their resolution, making macrophage cell therapy a promising strategy for regenerative medicine. However, since macrophages change rapidly in response to microenvironmental cues, their phenotype must be controlled post-administration. We present a tunable biomaterial-based strategy to control macrophages intracellularly via small molecule-releasing microparticles. Poly(lactic-co-glycolic acid) microparticles encapsulating the anti-inflammatory and anti-fibrotic drug dexamethasone were administered to macrophages in vitro, with uptake rates controlled by different loading regimes. Microparticle dose and dexamethasone content directly affected macrophage phenotype and phagocytic capacity, independent of particle content per cell, leading to an overall pro-reparative, anti-inflammatory, anti-fibrotic phenotype with increased phagocytic and ECM degrading functionality. Intracellularly controlled macrophages partially maintained this phenotype in vivo in a murine pulmonary fibrosis model, with more prominent effects in a pro-fibrotic environment compared to pro-inflammatory. These results suggest that intracellular control using biomaterials has the potential to control macrophage phenotype post-administration, which is essential for successful macrophage cell therapy.

Imidazole functionalized photo-crosslinked aliphatic polycarbonate drug-eluting coatings on zinc alloys for osteogenesis, angiogenesis, and bacteriostasis in bone regeneration

Zinc (Zn) alloys have demonstrated significant potential in healing critical-sized bone defects. However, the clinical application of Zn alloys implants is still hindered by challenges including excessive release of zinc ions (Zn2+), particularly in the early stage of implantation, and absence of bio-functions related to complex bone repair processes. Herein, a biodegradable aliphatic polycarbonate drug-eluting coating was fabricated on zinc-lithium (Zn-Li) alloys to inhibit Zn2+ release and enhance the osteogenesis, angiogenesis, and bacteriostasis of Zn alloys. Specifically, the photo-curable aliphatic polycarbonates were co-assembled with simvastatin and deposited onto Zn alloys to produce a drug-loaded coating, which was crosslinked by subsequent UV light irradiation. During the 60 days long-term immersion test, the coating showed distinguished stable drug release and Zn2+ release inhibition properties. Benefiting from the regulated release of Zn2+ and simvastatin, the coating facilitated the adhesion, proliferation, and differentiation of MC3T3-E1 cells, as well as the migration and tube formation of EA.hy926 cells. Astonishingly, the coating also showed remarkable antibacterial properties against both S. aureus and E. coli. The in vivo rabbit critical-size femur bone defects model demonstrated that the drug-eluting coating could efficiently promote new bone formation and the expression of platelet endothelial cell adhesion molecule-1 (CD31) and osteocalcin (OCN). The enhancement of osteogenesis, angiogenesis, and bacteriostasis is achieved by precisely controlling of the released Zn2+ at an appropriate level, as well as the stable release profile of simvastatin. This tailored aliphatic polycarbonate drug-eluting coating provides significant potential for clinical applications of Zn alloys implants.

Biopolymer-based beads for the adsorptive removal of organic pollutants from wastewater: Current state and future perspectives

Among biopolymer-based adsorbents, composites in the form of beads have shown promising results in terms of high adsorption capacity and ease of separation from the effluents. This review addresses the potential of biopolymer-based beads to remediate wastewaters polluted with emerging organic contaminants, for instance dyes, active pharmaceutical ingredients, pesticides, phenols, oils, polyaromatic hydrocarbons, and polychlorinated biphenyls. High adsorption capacities up to 2541.76 mg g-1 for dyes, 392 mg g-1 for pesticides and phenols, 1890.3 mg g-1 for pharmaceuticals, and 537 g g-1 for oils and organic solvents have been reported. The review also attempted to convey to its readers the significance of wastewater treatment through adsorption by providing an overview on decontamination technologies of organic water contaminants. Various preparation methods of biopolymer-based gel beads and adsorption mechanisms involved in the process of decontamination have been summarized and analyzed. Therefore, we believe there is an urge to discuss the current state of the application of biopolymer-based gel beads for the adsorption of organic pollutants from wastewater and future perspectives in this regard since it is imperative to treat wastewater before releasing into freshwater bodies.

One-step synthesis of amphiphilic copolymers PDMS-b-PEG using tris(pentafluorophenyl)borane and subsequent study of encapsulation and release of curcumin

A series of amphiphilic block copolymer (BCP) micelles based on poly(dimethylsiloxane) (PDMS) and poly(ethylene glycol) (PEG) were synthesized by a one-step reaction in the presence of tris(pentafluorophenyl)borane (BCF) as a catalyst. The structural composition of PDMS-b-PEG (PR11) and PEG-b-PDMS-b-PEG (PR12) was corroborated by FTIR, 29Si NMR, and TGA. The BCPs were assembled in an aqueous solution, obtaining micelles between 57 and 87 nm in size. PR11 exhibited a higher (2.0 g L-1) critical micelle concentration (CMC) than PR12 (1.5 g L-1) due to the short chain length. The synthesized nano micelles were used to encapsulate curcumin, which is one of three compounds of turmeric plant 'Curcuma longa' with significant biological activities, including antioxidant, chemoprotective, antibacterial, anti-inflammatory, antiviral, and anti-depressant properties. The encapsulation efficiency of curcumin was 60% for PR11 and 45% for PR12. Regarding the release study, PR11 delivered 53% curcumin after five days under acidic conditions (pH of 1.2) compared to 43% at a pH of 7.4. The degradation products of curcumin were observed under basic conditions and were more stable at acidic pH. In both situations, the release process is carried out by breaking the silyl-ether bond, allowing the release of curcumin. PR11 showed prolonged release times, so it could be used to reduce ingestion times and simultaneously work as a nanocarrier for other hydrophobic drugs.

Water absorption in artificial composites: Curse or blessing?

OBJECTIVES

This study evaluated the impact of mutable water uptake on the durability of mechanical properties and the long-term reliability of artificial composites.

METHODS

Three resin-based CAD/CAM restorative materials (CRMs) were investigated in three-point bending tests to calculate flexural strength (FS), modulus of elasticity (ME), modulus of resilience (MR), modulus of toughness (MT), and elastic recovery (ER). All specimens (n = 180) were stored under the same conditions and tested in four subsets (n = 15 per material) that were respectively withdrawn after repeated thermocycling (5000 cycles; 5-55 °C, H2O) and repetitive drying (7 d; 37 °C, air). For every specimen, weight differences were determined per storage condition. Likewise, loss tangent data were separately recorded via dynamic mechanical analysis to reliably assess damping characteristics.

RESULTS

Repeated thermocycling always induced weight increase and a concurrent significant loss in all mechanical properties except for MT and ER of a polymethylmethacrylate-based CRM. Drying consistently provoked weight loss and raised mechanical properties to initial values. Weight increase, however, enhanced loss tangent values and accordingly distinct damping characteristics, whereas weight decrease markedly lowered damping properties.

SIGNIFICANCE

Water uptake repeatedly induced a decrease in common mechanical properties but concurrently increased damping behavior. Invertible equilibrium processes were found with no evidence for permanent material degradation.

Advances in microbial exoenzymes bioengineering for improvement of bioplastics degradation

Plastic pollution has become a major global concern, posing numerous challenges for the environment and wildlife. Most conventional ways of plastics degradation are inefficient and cause great damage to ecosystems. The development of biodegradable plastics offers a promising solution for waste management. These plastics are designed to break down under various conditions, opening up new possibilities to mitigate the negative impact of traditional plastics. Microbes, including bacteria and fungi, play a crucial role in the degradation of bioplastics by producing and secreting extracellular enzymes, such as cutinase, lipases, and proteases. However, these microbial enzymes are sensitive to extreme environmental conditions, such as temperature and acidity, affecting their functions and stability. To address these challenges, scientists have employed protein engineering and immobilization techniques to enhance enzyme stability and predict protein structures. Strategies such as improving enzyme and substrate interaction, increasing enzyme thermostability, reinforcing the bonding between the active site of the enzyme and substrate, and refining enzyme activity are being utilized to boost enzyme immobilization and functionality. Recently, bioengineering through gene cloning and expression in potential microorganisms, has revolutionized the biodegradation of bioplastics. This review aimed to discuss the most recent protein engineering strategies for modifying bioplastic-degrading enzymes in terms of stability and functionality, including enzyme thermostability enhancement, reinforcing the substrate binding to the enzyme active site, refining with other enzymes, and improvement of enzyme surface and substrate action. Additionally, discovered bioplastic-degrading exoenzymes by metagenomics techniques were emphasized.

Cutting-edge approaches for targeted drug delivery in breast cancer: beyond conventional therapies

Breast cancer is a global health challenge with staggering statistics underscoring its pervasive impact. The burden of this disease is measured in terms of its prevalence and the challenges it poses to healthcare systems, necessitating a closer look at its epidemiology and impact. Current breast cancer treatments, including surgery, chemotherapy, radiation therapy, and targeted therapies, have made significant strides in improving patient outcomes. However, they are not without limitations, often leading to adverse effects and the development of drug resistance. This comprehensive review delves into the complex landscape of breast cancer, including its incidence, current treatment modalities, and the inherent limitations of existing therapeutic approaches. It also sheds light on the promising role of nanotechnology, encompassing both inorganic and organic nanoparticles equipped with the ability to selectively deliver therapeutic agents to tumor sites, in the battle against breast cancer. The review also addresses the emerging therapies, their associated challenges, and the future prospects of targeted drug delivery in breast cancer management.

Polyethersulfone Polymer for Biomedical Applications and Biotechnology

Polymers stand out as promising materials extensively employed in biomedicine and biotechnology. Their versatile applications owe much to the field of tissue engineering, which seamlessly integrates materials engineering with medical science. In medicine, biomaterials serve as prototypes for organ development and as implants or scaffolds to facilitate body regeneration. With the growing demand for innovative solutions, synthetic and hybrid polymer materials, such as polyethersulfone, are gaining traction. This article offers a concise characterization of polyethersulfone followed by an exploration of its diverse applications in medical and biotechnological realms. It concludes by summarizing the significant roles of polyethersulfone in advancing both medicine and biotechnology, as outlined in the accompanying table.

Advancements in wound healing: integrating biomolecules, drug delivery carriers, and targeted therapeutics for enhanced tissue repair

Wound healing, a critical biological process vital for tissue restoration, has spurred a global market exceeding $15 billion for wound care products and $12 billion for scar treatment. Chronic wounds lead to delayed or impaired wound healing. Natural bioactive compounds, prized for minimal side effects, stand out as promising candidates for effective wound healing. In response, researchers are turning to nanotechnology, employing the encapsulation of these agents into drug delivery carriers. Drug delivery system will play a crucial role in enabling targeted delivery of therapeutic agents to promote tissue regeneration and address underlying issues such as inflammation, infection, and impaired angiogenesis in chronic wound healing. Drug delivery carriers offer distinct advantages, exhibiting a substantial ratio of surface area to volume and altered physical and chemical properties. These carriers facilitate sustained and controlled release, proving particularly advantageous for the extended process of wound healing, that typically comprise a diverse range of components, integrating both natural and synthetic polymers. Additionally, they often incorporate bioactive molecules. Despite their properties, including poor solubility, rapid degradation, and limited bioavailability, various natural bioactive agents face challenges in clinical applications. With a global research, emphasis on harnessing nanomaterial for wound healing application, this research overview engages advancing drug delivery technologies to augment the effectiveness of tissue regeneration using bioactive molecules. Recent progress in drug delivery has poised to enhance the therapeutic efficacy of natural compounds in wound healing applications.

Unveiling the potentials of hydrophilic and hydrophobic polymers in microparticle systems: Opportunities and challenges in processing techniques

Conventional drug delivery systems are associated with various shortcomings, including low bioavailability and limited control over release. Biodegradable polymeric microparticles have emerged as versatile carriers in drug delivery systems addressing all these challenges. This comprehensive review explores the dynamic landscape of microparticles, considering the role of hydrophilic and hydrophobic materials. Within the continuously evolving domain of microparticle preparation methods, this review offers valuable insights into the latest advancements and addresses the factors influencing microencapsulation, which is pivotal for harnessing the full potential of microparticles. Exploration of the latest research in this dynamic field unlocks the possibilities of optimizing microencapsulation techniques to produce microparticles of desired characteristics and properties for different applications, which can help contribute to the ongoing evolution in the field of pharmaceutical science.

Nanocarriers address intracellular barriers for efficient drug delivery, overcoming drug resistance, subcellular targeting and controlled release

The cellular barriers are major bottlenecks for bioactive compounds entering into cells to accomplish their biological functions, which limits their biomedical applications. Nanocarriers have demonstrated high potential and benefits for encapsulating bioactive compounds and efficiently delivering them into target cells by overcoming a cascade of intracellular barriers to achieve desirable therapeutic and diagnostic effects. In this review, we introduce the cellular barriers ahead of drug delivery and nanocarriers, as well as summarize recent advances and strategies of nanocarriers for increasing internalization with cells, promoting intracellular trafficking, overcoming drug resistance, targeting subcellular locations and controlled drug release. Lastly, the future perspectives of nanocarriers for intracellular drug delivery are discussed, which mainly focus on potential challenges and future directions. Our review presents an overview of intracellular drug delivery by nanocarriers, which may encourage the future development of nanocarriers for efficient and precision drug delivery into a wide range of cells and subcellular targets.

Influence of Polymeric Microparticle Size and Loading Concentration on 3D Printing Accuracy and Degradation Behavior of Composite Scaffolds

Successful employment of 3D printing for delivery of therapeutic biomolecules requires protection of their bioactivity on exposure to potentially inactivating conditions. Although intermediary encapsulation of the biomolecules in polymeric particulate delivery vehicles is a promising strategy for this objective, the inclusion of such particles in 3D printing formulations may critically impact the accuracy or precision of 3D printed scaffolds relative to their intended designed architectures, as well as the degradation behavior of both the scaffolds and the included particles. The present work aimed to elucidate the effect of poly(d,l-lactic-co-glycolic acid) particle size and loading concentration on material accuracy, machine precision, and degradation of 3D printed poly(ɛ-caprolactone)-based scaffolds. Using a main effects analysis, the sizes and loading concentrations of particle delivery vehicles investigated were found to have neither a beneficial nor disadvantageous influence on the metrics of printing quality such as material accuracy and machine precision. Meanwhile, particle loading concentration was determined to influence degradation rate, whereas printing temperature affected the trends in composite weight-average molecular weight. Neither of the two particle-related parameters (concentration nor diameter) was found to exhibit a significant effect on intra-fiber nor inter-fiber porosity. These findings evidence the capacity for controlled loading of particulate delivery vehicles in 3D printed scaffolds while preserving construct accuracy and precision, and with predictable dictation of composite degradation behavior for potential controlled release of encapsulated biomolecules.

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.

Approaches for reducing chemo/radiation-induced cardiotoxicity by nanoparticles

Nanoparticles are fascinating and encouraging carriers for cancer treatment due to their extraordinary properties and potential applications in targeted drug delivery, treatment, and diagnosis. Experimental studies including in vitro and in vivo examinations show that nanoparticles can cause a revolution in different aspects of cancer therapy. Normal tissue toxicity and early and late consequences are the major limitations of cancer therapy by radiotherapy and chemotherapy. However, the delivery of drugs into tumors or reducing the accumulation of drugs in normal tissues can permit a more satisfactory response of malignancies to therapy with more inferior side effects. Cardiac toxicity is one of the major problems for chemotherapy and radiotherapy. Therefore, several experimental studies have been performed to minimize the degenerative impacts of cancer treatment on the heart and also enhance the influences of radiotherapy and chemotherapy agents in cancers. This review article emphasizes the benefits of nanoparticle-based drug delivery techniques, including minimizing the exposure of the heart to anticancer drugs, enhancing the accumulation of drugs in cancers, and expanding the effectiveness of radiotherapy. The article also discusses the challenges and problems accompanied with nanoparticle-based drug delivery techniques such as toxicity, which need to be addressed through further research. Moreover, the article emphasizes the importance of developing safe and effective nanoparticle-based therapies that can be translated into clinical practice.

Immunoregulatory effects of nanocurcumin in inflammatory milieu: Focus on COVID-19

The use of natural compounds, such as curcumin, to treat infections caused by bacteria, viruses, fungi, parasites, inflammatory diseases, and various types of cancer is an active and dynamic area of research. Curcumin has a long history of use in the food industry, and there is currently a growing interest in its therapeutic applications. Numerous clinical trials have consistently shown that curcumin, a polyphenolic compound, is safe and well-tolerated even at high doses. There is no toxicity limit. However, the clinical efficacy of curcumin has been limited by its constraints. However, scientific evidence indicates that the use of adjuvants and carriers, such as nanoparticles, exosomes, micelles, and liposomes, can help overcome this limitation. The properties, functions, and human benefits of using nanocurcumin are well-supported by scientific research. Recent evidence suggests that nanocurcumin may be a beneficial therapeutic modality due to its potential to decrease gene expression and secretion of specific inflammatory biomarkers involved in the cytokinestorm seen in severe COVID-19, as well as increase lymphocyte counts. Nanocurcumin has demonstrated the ability to improve clinical manifestations and modulate immune response and inflammation in various autoinflammatory diseases. Additionally, its efficacy, affordability, and safety make it a promising replacement for residual cancer cells after tumor removal. However, further studies are necessary to evaluate the safety and efficacy of nanocurcumin as a new therapeutic in clinical trials, including appropriate dosage, frequency, and duration.

Selectively coated contact lenses by nanoelectrospray (nES) to fabricate drug-eluting contact lenses for treating ocular diseases

Drug-eluting contact lenses (DECLs) incorporated with poly(lactic-co-glycolic acid) (PLGA) and various model drugs (ketotifen fumarate, bimatoprost and latanoprost) were fabricated using nanoelectrospray (nES) approach. The resulting DECLs demonstrated outstanding optical transmittance within the optical zone, indicating that the employed coating procedure did not compromise visual acuity under the prescribed spraying parameters. In vitro drug release assessments of the model drugs (ketotifen fumarate (KF), bimatoprost (BIM), and latanoprost (LN)) revealed a strong correlation between the model drug's hydrophobicity and the duration of drug release. Changing the drug loading of the more hydrophilic model drugs, BIM and KF, showed no impact on the drug release kinetics of DECLs loaded with BIM and KF. However, for the hydrophobic model drug, LN, the highest LN loading led to the most extended drug release. The conventional steam sterilisation method was found to damage the PLGA coating on the DECLs fabricated by nES. An alternative sterilisation strategy, such as radiation sterilisation may need to be investigated in the future study to minimise potential harm to the coating.

Coatings for Cardiovascular Stents-An Up-to-Date Review

Cardiovascular diseases (CVDs) increasingly burden health systems and patients worldwide, necessitating the improved awareness of current treatment possibilities and the development of more efficient therapeutic strategies. When plaque deposits narrow the arteries, the standard of care implies the insertion of a stent at the lesion site. The most promising development in cardiovascular stents has been the release of medications from these stents. However, the use of drug-eluting stents (DESs) is still challenged by in-stent restenosis occurrence. DESs' long-term clinical success depends on several parameters, including the degradability of the polymers, drug release profiles, stent platforms, coating polymers, and the metals and their alloys that are employed as metal frames in the stents. Thus, it is critical to investigate new approaches to optimize the most suitable DESs to solve problems with the inflammatory response, delayed endothelialization, and sub-acute stent thrombosis. As certain advancements have been reported in the literature, this review aims to present the latest updates in the coatings field for cardiovascular stents. Specifically, there are described various organic (e.g., synthetic and natural polymer-based coatings, stents coated directly with drugs, and coatings containing endothelial cells) and inorganic (e.g., metallic and nonmetallic materials) stent coating options, aiming to create an updated framework that would serve as an inception point for future research.

Sample transformation in online separations: how chemical conversion advances analytical technology

While the advent of modern analytical technology has allowed scientists to determine the complexity of mixtures, it also spurred the demand to understand these sophisticated mixtures better. Chemical transformation can be used to provide insights into properties of complex samples such as degradation pathways or molecular heterogeneity that are otherwise unaccessible. In this article, we explore how sample transformation is exploited across different application fields to empower analytical methods. Transformation mechanisms include molecular-weight reduction, controlled degradation, and derivatization. Both offline and online transformation methods have been explored. The covered studies show that sample transformation facilitates faster reactions (e.g. several hours to minutes), reduces sample complexity, unlocks new sample dimensions (e.g. functional groups), provides correlations between multiple sample dimensions, and improves detectability. The article highlights the state-of-the-art and future prospects, focusing in particular on the characterization of protein and nucleic-acid therapeutics, nanoparticles, synthetic polymers, and small molecules.

Superparamagnetic Artificial Cells PLGA-Fe3O4 Micro/Nanocapsules for Cancer Targeted Delivery

Artificial cells have been extensively used in many fields, such as nanomedicine, biotherapy, blood substitutes, drug delivery, enzyme/gene therapy, cancer therapy, and the COVID-19 vaccine. The unique properties of superparamagnetic Fe3O4 nanoparticles have contributed to increased interest in using superparamagnetic artificial cells (PLGA-Fe3O4 micro/nanocapsules) for targeted therapy. In this review, the preparation methods of Fe3O4 NPs and superparamagnetic artificial cell PLGA-drug-Fe3O4 micro/nanocapsules are discussed. This review also focuses on the recent progress of superparamagnetic PLGA-drug-Fe3O4 micro/nanocapsules as targeted therapeutics. We shall concentrate on the use of superparamagnetic artificial cells in the form of PLGA-drug-Fe3O4 nanocapsules for magnetic hyperthermia/photothermal therapy and cancer therapies, including lung breast cancer and glioblastoma.

Magnetic Cellular Backpacks for Spatial Targeting, Imaging, and Immunotherapy

Adoptive cell transfer (ACT) therapies are growing in popularity due to their ability to interact with diseased tissues in a specific manner. Disc-shaped particles, or "backpacks", that bind to cellular surfaces show promise for augmenting the therapeutic potential of adoptively transferred cells by resisting phagocytosis and locally releasing drugs to maintain cellular activity over time. However, many ACTs suffer from limited tumor infiltration and retention and lack a method for real-time spatial analysis. Therefore, we have designed biodegradable backpacks loaded with superparamagnetic iron oxide nanoparticles (SPIONs) to improve upon current ACT strategies by (i) controlling the localization of cell-backpack complexes using gradient magnetic fields and (ii) enabling magnetic particle imaging (MPI) to track complexes after injection. We show that magnetic backpacks bound to macrophages and loaded with a proinflammatory drug, resiquimod, maintain anticancer phenotypes of carrier macrophages for 5 days and create cytokine "factories" that continuously release IL-12. Furthermore, we establish that forces generated by gradient magnet fields are sufficient to displace cell-backpack complexes in physiological settings. Finally, we demonstrate that MPI can be used to visualize cell-backpack complexes in mouse tumors, enabling a potential strategy to track the biodistribution of ACTs in real time.

Spray-dried nanocrystal-loaded polymer microparticles for long-term release local therapies: an opportunity for poorly soluble drugs

Nano- and micro-technologies can salvage drugs with very low solubility that were doomed to pre-clinical and clinical failure. A unique design approach to develop drug nanocrystals (NCs) loaded in extended release polymeric microparticles (MPs) for local treatments is presented here through the case of a potential osteoarthritis (OA) drug candidate for intra-articular (IA) administration. Optimizing a low-shear wet milling process allowed the production of NCs that can be subsequently freeze-dried (FD) and redispersed in a hydrophobic polymer-organic solvent solution to form spray-dried MPs. Results demonstrated a successful development of a ready-to-upscale formulation containing PLGA MPs with high drug NC encapsulation rates that showed a continuous and controlled drug release profile over four months. The screenings and procedures described allowed for identifying and overcoming common difficulties and challenges raised along the drug reduction to nano-size and spray-drying process. Above all, the technical knowledge acquired is intended for formulation scientists aiming to improve the therapeutic perspectives of poorly soluble drugs.

Bioadhesives with Antimicrobial Properties

Bioadhesives with antimicrobial properties enable easier and safer treatment of wounds as compared to the traditional methods such as suturing and stapling. Composed of natural or synthetic polymers, these bioadhesives seal wounds and facilitate healing while preventing infections through the activity of locally released antimicrobial drugs, nanocomponents, or inherently antimicrobial polers. Although many different materials and strategies are employed to develop antimicrobial bioadhesives, the design of these biomaterials necessitates a prudent approach as achieving all the required properties including optimal adhesive and cohesive properties, biocompatibility, and antimicrobial activity can be challenging. Designing antimicrobial bioadhesives with tunable physical, chemical, and biological properties will shed light on the path for future advancement of bioadhesives with antimicrobial properties. In this review, the requirements and commonly used strategies for developing bioadhesives with antimicrobial properties are discussed. In particular, different methods for their synthesis and their experimental and clinical applications on a variety of organs are reviewed. Advances in the design of bioadhesives with antimicrobial properties will pave the way for a better management of wounds to increase positive clinical outcomes.

Engineered Hierarchical Microdevices Enable Pre-Programmed Controlled Release for Postsurgical and Unresectable Cancer Treatment

Drug treatment is required for both resectable and unresectable cancers to strive for any meaningful improvement in patient outcomes. However, the clinical benefit of receiving conventional systemic administrations is often less than satisfactory. Drug delivery systems are preferable substitutes but still fail to meet diverse clinical demands due to the difficulty in programming drug release profiles. Herein, a microfabrication concept, termed "Hierarchical Multiple Polymers Immobilization" (HMPI), is introduced and biodegradable-polymer-based hierarchical microdevices (HMDs) that can pre-program any desired controlled release profiles are engineered. Based on the first-line medication of pancreatic and breast cancer, controlled release of single gemcitabine and the doxorubicin/paclitaxel combination in situ for multiple courses is implemented, respectively. Preclinical models of postsurgical pancreatic, postsurgical breast, and unresectable breast cancer are established, and the designed HMDs are demonstrated as well-tolerable and effective treatments for inhibiting tumor growth, recurrence, and metastasis. The proposed HMPI strategy allows the creation of tailorable and high-resolution hierarchical microstructures for pre-programming controlled release according to clinical medication schedules, which may provide promising alternative treatments for postsurgical and unresectable tumor control.

Polymeric Nanoformulation of Zoledronic Acid Rescues Osteoblasts from the Harmful Effect of its Native Form: An In Vitro Investigation of Cytotoxic Potential on Osteoblasts and Osteosarcoma Cells

Osteosarcoma (OS) is a malignant tumor, fatal for pediatric patients who do not respond to chemotherapy, alternative therapies and drugs can provide better outcomes. Zoledronic acid (Zol) belonging to the class of bisphosphonates (BPs) has a direct antitumor ability to prevent Ras GTPases modification and stimulate apoptosis. Despite advances in maintaining balance in skeletal events and direct anticancer properties, Zol causes cytotoxicity to normal healthy pre-osteoblast cells, hampering mineralization and differentiation. The study reports the preparation and evaluation of a nanoformulation that can diminish the existing drawbacks of native Zol. The cytotoxic effect is evaluated on bone cancer cells and healthy bone cells with three different cell lines namely, K7M2 (mouse OS cell line), SaOS2 (human OS cell line), and MC3T3E1 (healthy cell counterpart). It is observed that Zol nanoformulation is uptaken more (95%) in K7M2 whereas in MC3T3E1, the percent population internalizing nanoparticles (NPs) is 45%. Zol has a sustained release of 15% after 96 h from the NP which leads to a rescuing effect on the normal pre-osteoblast cells. In conclusion, it can be stated that Zol nanoformulation can be used as a good platform for a sustained release system with minimum side effects to normal bone cells.

Novel Nanotherapeutic Systems Based on PEGylated Squalene Micelles for Enhanced In Vitro Activity of Methotrexate and Cytarabine

Nanomedicine has garnered significant attention due to the advantages it offers in the treatment of cancer-related disorders, some of the deadliest diseases affecting human lives. Conventional medication formulations often encounter issues of instability or insolubility in biological environments, resulting in low bioavailability. Nanocarriers play a crucial role in transporting and safeguarding drugs at specific sites of action, enabling gradual release under particular conditions. This study focuses on methotrexate (MTx) and cytarabine (Cyt), essential antitumoral drugs, loaded into PEGylated squalene micellar structures to enhance therapeutic effectiveness and minimize drawbacks. The micelles were prepared using ultrasound-assisted methods in both water and phosphate buffer saline solutions. Evaluation of drug-loaded micelles encompassed parameters such as particle size, colloidal stability, surface charge, morphology, encapsulation efficiency, drug loading capacity, and in vitro release profiles under simulated physiological and tumoral conditions. In vitro cell inhibition studies conducted on MCF-7 and HeLa cell lines demonstrated higher antitumoral activity for the drug-encapsulated micelles compared to free drugs. The encapsulation effectively addressed the burst effect, providing sustained release for at least 48 h while enhancing the drug's protection under physiological conditions.

Pairing-Enhanced Regioselectivity: Synthesis of Alternating Poly(lactic-co-glycolic acid) from Racemic Methyl-Glycolide

Poly(lactic-co-glycolic acid) (PLGA) is used in vivo for various biomedical applications. Due to its biodegradability and biocompatibility, PLGA is uniquely suited for controlled drug delivery with parenteral administration. Previously, we established the synthesis of isotactic, alternating PLGA from enantiopure starting materials. Here, to fill in the gap of the current field, we have developed the synthesis of syndioenriched, alternating PLGA from racemic methyl-glycolide (rac-MeG). The synthesis of alternating PLGA is accomplished by a highly regioselective ring-opening polymerization of rac-MeG with an optimized racemic aluminum catalyst. Mechanistic studies are carried out to elucidate the pairing-enhanced catalyst regio- and stereocontrol. Polymer sequence fidelity has been established by NMR investigations, confirming a high degree of alternation of the comonomer sequence and moderate syndiotacticity within the backbone stereoconfiguration. The resulting syndioenriched material is amorphous, which will facilitate the drug complexation behavior.

Promising New Horizons in Medicine: Medical Advancements with Nanocomposite Manufacturing via 3D Printing

Three-dimensional printing technology has fundamentally revolutionized the product development processes in several industries. Three-dimensional printing enables the creation of tailored prostheses and other medical equipment, anatomical models for surgical planning and training, and even innovative means of directly giving drugs to patients. Polymers and their composites have found broad usage in the healthcare business due to their many beneficial properties. As a result, the application of 3D printing technology in the medical area has transformed the design and manufacturing of medical devices and prosthetics. Polymers and their composites have become attractive materials in this industry because of their unique mechanical, thermal, electrical, and optical qualities. This review article presents a comprehensive analysis of the current state-of-the-art applications of polymer and its composites in the medical field using 3D printing technology. It covers the latest research developments in the design and manufacturing of patient-specific medical devices, prostheses, and anatomical models for surgical planning and training. The article also discusses the use of 3D printing technology for drug delivery systems (DDS) and tissue engineering. Various 3D printing techniques, such as stereolithography, fused deposition modeling (FDM), and selective laser sintering (SLS), are reviewed, along with their benefits and drawbacks. Legal and regulatory issues related to the use of 3D printing technology in the medical field are also addressed. The article concludes with an outlook on the future potential of polymer and its composites in 3D printing technology for the medical field. The research findings indicate that 3D printing technology has enormous potential to revolutionize the development and manufacture of medical devices, leading to improved patient outcomes and better healthcare services.

Enhancing antioxidant delivery through 3D printing: a pathway to advanced therapeutic strategies

The rapid advancement of 3D printing has transformed industries, including medicine and pharmaceuticals. Integrating antioxidants into 3D-printed structures offers promising therapeutic strategies for enhanced antioxidant delivery. This review explores the synergistic relationship between 3D printing and antioxidants, focusing on the design and fabrication of antioxidant-loaded constructs. Incorporating antioxidants into 3D-printed matrices enables controlled release and localized delivery, improving efficacy while minimizing side effects. Customization of physical and chemical properties allows tailoring of antioxidant release kinetics, distribution, and degradation profiles. Encapsulation techniques such as direct mixing, coating, and encapsulation are discussed. Material selection, printing parameters, and post-processing methods significantly influence antioxidant release kinetics and stability. Applications include wound healing, tissue regeneration, drug delivery, and personalized medicine. This comprehensive review aims to provide insights into 3D printing-assisted antioxidant delivery systems, facilitating advancements in medicine and improved patient outcomes for oxidative stress-related disorders.

A Degradable Sustained-Release Drug Delivery System for Bleb-Forming Glaucoma Surgery

Fibrosis of the filtering bleb is one of the main causes of failure after bleb-forming glaucoma surgery. Intraoperative application of mitomycin C (MMC) is the current gold standard to reduce the fibrotic response. However, MMC is cytotoxic and one-time application is often insufficient. A sustained-release drug delivery system (DDS), loaded with MMC, may be less cytotoxic and equally or more effective. Two degradable (polycaprolactone (PCL) and polylactic-co-glycolic acid (PLGA)) MMC-loaded DDSs are developed. Release kinetics are first assessed in vitro followed by rabbit implants in conjunction with the PRESERFLO MicroShunt. As a control, the MicroShunt is implanted with adjunctive use of a MMC solution. Rabbits are euthanized at postoperative day (POD) 28 and 90. The PLGA and PCL DDSs release (on average) 99% and 75% of MMC, respectively. All groups show functioning blebs until POD 90. Rabbits implanted with a DDS show more inflammation with avascular thin-walled blebs when compared to the control. However, collagen is more loosely arranged. The PLGA DDS shows less inflammation, less foreign body response (FBR), and more complete degradation at POD 90 when compared to the PCL DDS. Further optimization with regard to dosage is required to reduce side effects to the conjunctiva.

Increased radical scavenging activity of thymoquinone and l-ascorbic acid dual encapsulated in palmitoyl-chitosan nanoparticles in a human normal lung fibroblast, MRC-5 due to synergistic antioxidative effects

Less effective antioxidant supplementation in combating free radicals is often related to the lack of the formulation of carriers. The antioxidant may be one of the most powerful substances but is marred by poor uptake by cells when the carrier degraded and dissolved too rapidly. Nanoparticle (NP) systems are promising in overcoming the problem since they provide high surface area to enhance encapsulation and release efficiency. With the right selection of material, NP carriers could function as constructive antioxidant cargos. Generally, NPs carry only one active ingredient; this study, however, utilized chitosan nanoparticles (CNPs) and hydrophobically modified palmitoyl-chitosan nanoparticles (PCNPs) that were dual encapsulated with antioxidants of different polarities, namely, hydrophobic thymoquinone (TQ) and hydrophilic l-ascorbic acid (LAA) to evaluate their combination effects in scavenging free radicals. The antioxidants followed zero-order release kinetics with a controlled release manner for about 48 h. The interaction effects between TQ and LAA loaded in the NP systems were determined by classical isobologram (CI) values. The CI values were derived by a diphenyl picrylhydrazyl (DPPH) assay, a radical scavenging activity assay. Combined TQ and LAA had CI values of less than one, with a lower value in the PCNP system than in the CNP system. This indicates that the interaction between those antioxidants showed higher synergistic effects in PCNPs, which enhanced the DPPH radical scavenging activities. The antioxidative potential of compound(s) encapsulated in the PCNP carrier was further experimented by a reactive oxygen species (ROS) assay on a human normal lung fibroblast cell line (MRC-5) as lung is one of the organs with high accumulation of free radicals. About 48 h post treatment, the dual-loaded TQ and LAA in PCNPs showed the lowest ROS level in comparison to single-loaded antioxidants and bare antioxidant delivery. The hydrogen peroxide (H2O2) radical scavenging was influenced by both the controlled release property of the PCNP system and the synergy between TQ and LAA. In short, dual-loaded TQ and LAA in the hydrophobically modified PCNP had effectively depicted the capability of a single CS-based nanocarrier to hold more than one compound at a time to function as a potent radical scavenger.

Role of the Lactide:Glycolide Ratio in PLGA Nanoparticle Stability and Release under Lysosomal Conditions for Enzyme Replacement Therapy of Lysosomal Storage Disorders

Prior studies demonstrated that encapsulation in poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) enhanced the delivery of enzymes used for replacement therapy (ERT) of lysosomal storage disorders (LSDs). This study examined how the copolymer lactide:glycolide ratio impacts encapsulation, physicochemical characteristics, stability, and release under lysosomal conditions. Hyaluronidase, deficient in mucopolysaccharidosis IX, was encapsulated in NPs synthesized using 50:50, 60:40, or 75:25 lactide:glycolide copolymers. All NPs had diameters compatible with cellular transport (≤168 nm) and polydispersity indexes (≤0.16) and ζ-potentials (≤-35 mV) compatible with colloidal stability. Yet, their encapsulation efficiency varied, with 75:25 NPs and 60:40 NPs having the lowest and highest EE, respectively (15% vs. 28%). Under lysosomal conditions, the 50:50 copolymer degraded fastest (41% in 1 week), as expected, and the presence of a targeting antibody coat did not alter this result. Additionally, 60:40 NPs destabilized fastest (<1 week) because of their smaller diameter, and 75:25 NPs did not destabilize in 4 weeks. All formulations presented burst release under lysosomal conditions (56-78% of the original load within 30 min), with 50:50 and 60:40 NPs releasing an additional small fraction after week 1. This provided 4 weeks of sustained catalytic activity, sufficient to fully degrade a substrate. Altogether, the 60:40 NP formulation is preferred given its higher EE, and 50:50 NPs represent a valid alternative, while the highest stability of 75:25 NPs may impair lysosomes. These results can guide future studies aiming to translate PLGA NP-based ERT for this and other LSDs.

Microrobots for Biomedicine: Unsolved Challenges and Opportunities for Translation

Microrobots are being explored for biomedical applications, such as drug delivery, biological cargo transport, and minimally invasive surgery. However, current efforts largely focus on proof-of-concept studies with nontranslatable materials through a "design-and-apply" approach, limiting the potential for clinical adaptation. While these proof-of-concept studies have been key to advancing microrobot technologies, we believe that the distinguishing capabilities of microrobots will be most readily brought to patient bedsides through a "design-by-problem" approach, which involves focusing on unsolved problems to inform the design of microrobots with practical capabilities. As outlined below, we propose that the clinical translation of microrobots will be accelerated by a judicious choice of target applications, improved delivery considerations, and the rational selection of translation-ready biomaterials, ultimately reducing patient burden and enhancing the efficacy of therapeutic drugs for difficult-to-treat diseases.

Effect of polycation coating on the long-term pulsatile release of antigenic ESAT-61-20 peptide from PLGA nanoparticles

The development of novel vaccine formulations against tuberculosis is necessary to reduce the number of new cases worldwide. Polymeric nanoparticles offer great potential as antigen delivery and immunostimulant systems for such purposes. In the study, we have encapsulated the antigenic peptide epitope of ESAT-6 protein of M. tuberculosis into PLGA nanoparticles and coated these nanoparticles with the cationic polymer of quaternized poly(4-vinylpyridine) (QPVP) to obtain a positively charged system as a potential nasal vaccine prototype. The produced spherical nanoparticles had hydrodynamic diameters between 180 and 240 nm with a narrow size distribution. The non-coated nanoparticle exhibited a 3-phase in vitro release profile that was completed in more than 4 months. In this release study, 5% of the peptide was released in the first 6 h and the nanoparticle remained silent until the 70th day. Then, an additional 5% of the peptide was released in 45 days. After coating the nanoparticle with QPVP, the release periods and peptide amounts dramatically changed. The antigenic peptide-loaded nanoparticles coated with the polycation stimulated the macrophages in vitro to release more nitric oxide (NO) compared to the free peptide and non-coated nanoparticle, which reveals the immunostimulant activity of the produced nanoparticle systems. The produced non-coated nanoparticles with the prolonged pulsatile release of the antigenic peptide can be used in the development of single injection self-boosting vaccine formulations. By coating these nanoparticles, both the release profile and immunogenicity can be changed.

Contrasting Properties of Polymeric Nanocarriers for MRI-Guided Drug Delivery

Poor pharmacokinetics and low aqueous solubility combined with rapid clearance from the circulation of drugs result in their limited effectiveness and generally high therapeutic doses. The use of nanocarriers for drug delivery can prevent the rapid degradation of the drug, leading to its increased half-life. It can also improve the solubility and stability of drugs, advance their distribution and targeting, ensure a sustained release, and reduce drug resistance by delivering multiple therapeutic agents simultaneously. Furthermore, nanotechnology enables the combination of therapeutics with biomedical imaging agents and other treatment modalities to overcome the challenges of disease diagnosis and therapy. Such an approach is referred to as "theranostics" and aims to offer a more patient-specific approach through the observation of the distribution of contrast agents that are linked to therapeutics. The purpose of this paper is to present the recent scientific reports on polymeric nanocarriers for MRI-guided drug delivery. Polymeric nanocarriers are a very broad and versatile group of materials for drug delivery, providing high loading capacities, improved pharmacokinetics, and biocompatibility. The main focus was on the contrasting properties of proposed polymeric nanocarriers, which can be categorized into three main groups: polymeric nanocarriers (1) with relaxation-type contrast agents, (2) with chemical exchange saturation transfer (CEST) properties, and (3) with direct detection contrast agents based on fluorinated compounds. The importance of this aspect tends to be downplayed, despite its being essential for the successful design of applicable theranostic nanocarriers for image-guided drug delivery. If available, cytotoxicity and therapeutic effects were also summarized.

Biomedical applications of PLGA nanoparticles in nanomedicine: advances in drug delivery systems and cancer therapy

INTRODUCTION

During the last decades, the ever-increasing proportion of patients with cancer has been led to serious concerns worldwide. Therefore, the development and use of novel pharmaceuticals, like nanoparticles (NPs)-based drug delivery systems (DDSs), can be potentially effective in cancer therapy.

AREA COVERED

Poly lactic-co-glycolic acid (PLGA) NPs, as a kind of bioavailable, biocompatible, and biodegradable polymers, have approved by the Food and Drug Administration (FDA) for some biomedical and pharmaceutical applications. PLGA is comprised of lactic acid (LA) and glycolic acid (GA) and their ratio could be controlled during various syntheses and preparation approaches. LA/GA ratio determines the stability and degradation time of PLGA; lower content of GA results in fast degradation. There are several approaches for preparing PLGA NPs that can affect their various aspects, such as size, solubility, stability, drug loading, pharmacokinetics, and pharmacodynamics, and so on.

EXPERT OPINION

These NPs have indicated the controlled and sustained drug release in the cancer site and can use in passive and active (via surface modification) DDSs. This review aims to provide an overview of PLGA NPs, their preparation approach and physicochemical aspects, drug release mechanism and the cellular fate, DDSs for efficient cancer therapy, and status in the pharmaceutical industry and nanomedicine.

Optimization and characterization of miRNA-129-5p-encapsulated poly (lactic-co-glycolic acid) nanoparticles to reprogram activated microglia

Microglia have become a therapeutic target of many inflammation-mediated diseases in the central nervous system (CNS). Recently, microRNA (miRNA) has been proposed as an important regulator of immune responses. Specifically, miRNA-129-5p has been shown to play critical roles in the regulation of microglia activation. We have demonstrated that biodegradable poly (lactic-co-glycolic acid) (PLGA)-based nanoparticles (NPs) modulated innate immune cells and limited neuroinflammation after injury to the CNS. In this study, we optimized and characterized PLGA-based NPs for miRNA-129-5p delivery to utilize their synergistic immunomodulatory features for activated microglia modulation. A series of nanoformulations employing multiple excipients including epigallocatechin gallate (EGCG), spermidine (Sp), or polyethyleneimine (PEI) for miRNA-129-5p complexation and miRNA-129-5p conjugation to PLGA (PLGA-miR) were utilized. We characterized a total of six nanoformulations through physicochemical, biochemical, and molecular biological methods. In addition, we investigated the immunomodulatory effects of multiple nanoformulations. The data indicated that the immunomodulatory effects of nanoformulation, PLGA-miR with the excipient Sp (PLGA-miR+Sp) and PEI (PLGA-miR+PEI) were significant compared to other nanoformulations including naked PLGA-based NP. These nanoformulations promoted a sustained release of miRNA-129-5p and polarization of activated microglia into a more pro-regenerative phenotype. Moreover, they enhanced the expression of multiple regeneration-associated factors, while alleviating the expression of pro-inflammatory factors. Collectively, the proposed nanoformulations in this study highlight the promising therapeutic tools for synergistic immunomodulatory effects between PLGA-based NPs and miRNA-129-5p to modulate activated microglia which will have numerous applications for inflammation-derived diseases.

Nanodelivery of scutellarin induces immunogenic cell death for treating hepatocellular carcinoma

Hepatocellular carcinoma (HCC) causes the immunosuppressive tumor microenvironment (TME) resistant to current immunotherapy. The immunogenic apoptosis (currently termed immunogenic cell death, ICD) of cancer cells may induce the adaptive immunity against tumors, thereby providing great potential for treating HCC. In this study, we have confirmed the potential of scutellarin (SCU, a flavonoid found in Erigeron breviscapus) for triggering ICD in HCC cells. To facilitate in vivo application of SCU for HCC immunotherapy, an aminoethyl anisamide-targeted polyethylene glycol-modified poly(lactide-co-glycolide) (PLGA-PEG-AEAA) was produced to facilitate SCU delivery in this study. The resultant nanoformulation (PLGA-PEG-AEAA.SCU) remarkably promoted blood circulation and tumor delivery in the orthotopic HCC mouse model. Consequently, PLGA-PEG-AEAA.SCU reversed the immune suppressive TME and achieved the immunotherapeutic efficacy, resulting in significantly longer survival of mice, without inducing toxicity. These findings uncover the ICD potential of SCU and provide a promising strategy for HCC immunotherapy.

Biocompatible polymeric microparticles serve as novel and reliable vehicles for exogenous hormone manipulations in passerines

The administration of exogenous hormones emerged as an essential tool for field studies in endocrinology. However, working with wild animals remains challenging, because under field conditions not every available method meets the necessary requirements. Achieving a sustained elevation in hormone levels, while simultaneously minimising handling time and invasiveness of the procedure is a difficult task in field endocrinology. Facing this challenge, we have investigated the suitability of biocompatible polymeric microparticles, a novel method for drug-administration, as a tool to manipulate hormones in small songbirds. We chose the insulin-like growth factor-1 (IGF-1) as target hormone, because it receives great interest from the research community due to its important role in shaping life-history traits. Moreover, its short half-life and hydrophilic properties imply a major challenge in finding a suitable method to achieve a sustained, systemic long-term release. To study the release kinetics, we injected either IGF-1 loaded polylactic-co-glycolic acid (PLGA) microparticles or dispersion medium (control group) in the skin pocket of the interscapular region of captive bearded reedlings (Panurus biarmicus). We collected blood samples for 7 consecutive days plus an additional sampling period after two weeks and complemented these with an in vitro experiment. Our results show that in vitro, PLGA microparticles allowed a stable IGF-1 release for more than 15 days, following a burst release at the beginning of the measurement. In vivo, the initial burst was followed by a drop to still elevated levels in circulating IGF-1 until the effect vanished by 16 days post-treatment. This study is the first to describe the use of PLGA-microparticles as a novel tool for exogenous hormone administration in a small passerine. We suggest that this method is highly suitable to achieve the systemic long-term release of hydrophilic hormones with short half-life and reduces overall handling time, as it requires only one subcutaneous injection.

A Versatile Brij-Linker for One-Step Preparation of Targeted Nanoparticles

Background: Most frequently the functionalization of nanoparticles is hampered by time-consuming, sometimes harsh conjugation and purification procedures causing premature drug release and/or degradation. A strategy to circumvent multi-step protocols is to synthesize building blocks with different functionalities and to use mixtures thereof for nanoparticle preparation in one step. Methods: BrijS20 was converted into an amine derivative via a carbamate linkage. The Brij-amine readily reacts with pre-activated carboxyl-containing ligands such as folic acid. The structures of the building blocks were confirmed by different spectroscopic methods and their utility was assessed by one-step preparation and characterization of nanoparticles applying PLGA as a matrix polymer. Results: Nanoparticles were about 200 nm in diameter independent of the composition. Experiments with human folate expressing single cells and monolayer revealed that the nanoparticle building block Brij mediates a "stealth" effect and the Brij-amine-folate a "targeting" effect. As compared to plain nanoparticles, the stealth effect decreased the cell interaction by 13%, but the targeting effect increased the cell interaction by 45% in the monolayer. Moreover, the targeting ligand density and thus the cell association of the nanoparticles is easily fine-tuned by selection of the initial ratio of the building blocks. Conclusions: This strategy might be a first step towards the one-step preparation of nanoparticles with tailored functionalities. Relying on a non-ionic surfactant is a versatile approach as it might be extended to other hydrophobic matrix polymers and promising targeting ligands from the biotech pipeline.

Properties of Poly (Lactic-co-Glycolic Acid) and Progress of Poly (Lactic-co-Glycolic Acid)-Based Biodegradable Materials in Biomedical Research

In recent years, biodegradable polymers have gained the attention of many researchers for their promising applications, especially in drug delivery, due to their good biocompatibility and designable degradation time. Poly (lactic-co-glycolic acid) (PLGA) is a biodegradable functional polymer made from the polymerization of lactic acid (LA) and glycolic acid (GA) and is widely used in pharmaceuticals and medical engineering materials because of its biocompatibility, non-toxicity, and good plasticity. The aim of this review is to illustrate the progress of research on PLGA in biomedical applications, as well as its shortcomings, to provide some assistance for its future research development.

Model-based Optimization of Drug Release Rate from a Size Distributed Population of Biodegradable Polymer Carriers

In the present study, a comprehensive polymer degradation-drug diffusion model is developed to describe the polymer degradation kinetics and quantify the release rate of an active pharmaceutical ingredient (API) from a size-distributed population of drug-loaded poly(lactic-co-glycolic) acid (PLGA) carriers in terms of material and morphological properties of the drug carriers. To take into account the spatial-temporal variation of the drug and water diffusion coefficients, three new correlations are developed in terms of spatial-temporal variation of the molecular weight of the degrading polymer chains. The first one relates the diffusion coefficients with the time-spatial variation of the molecular weight of PLGA and initial drug loading and, the second one with the initial particle size, and the third one with evolution of the particle porosity due to polymer degradation. The derived model, comprising a system of partial differential and algebraic equations, is numerically solved using the method of lines and validated against published experimental data on the drug release rate from a size distributed population of piroxicam-PLGA microspheres. Finally, a multi-parametric optimization problem is formulated to calculate the optimal particle size and drug loading distributions of drug-loaded PLGA carriers to realize a desired zero-order drug release rate of a therapeutic drug over a specified administration period of several weeks. It is envisaged that the proposed model-based optimization approach will aid the optimal design of new controlled drug delivery systems and, consequently, the therapeutic outcome of an administered drug.

Application of PLGA as a Biodegradable and Biocompatible Polymer for Pulmonary Delivery of Drugs

Pulmonary administration of biodegradable polymeric formulation is beneficial in the treatment of various respiratory diseases. For respiratory delivery, the polymer must be non-toxic, biodegradable, biocompatible, and stable. Poly D, L-lactic-co-glycolic acid (PLGA) is a widely used polymer for inhalable formulations because of its attractive mechanical and processing characteristics which give great opportunities to pharmaceutical industries to formulate novel inhalable products. PLGA has many pharmaceutical applications and its biocompatible nature produces non-toxic degradation products. The degradation of PLGA takes place through the non-enzymatic hydrolytic breakdown of ester bonds to produce free lactic acid and glycolic acid. The biodegradation products of PLGA are eliminated in the form of carbon dioxide (CO₂) and water (H₂O) by the Krebs cycle. The biocompatible properties of PLGA are investigated in various in vivo and in vitro studies. The high structural integrity of PLGA particles provides better stability, excellent drug loading, and sustained drug release. This review provides detailed information about PLGA as an inhalable grade polymer, its synthesis, advantages, physicochemical properties, biodegradability, and biocompatible characteristics. The important formulation aspects that must be considered during the manufacturing of inhalable PLGA formulations and the toxicity of PLGA in the lungs are also discussed in this paper. Additionally, a thorough overview is given on the application of PLGA as a particulate carrier in the treatment of major respiratory diseases, such as cystic fibrosis, lung cancer, tuberculosis, asthma, and pulmonary hypertension.

PLGA-based nanoparticles for the treatment of cancer: current strategies and perspectives

Research on cancer treatment is always of great importance because of the extensive and difficult treatment options and side effects of chemotherapeutic agents. Due to this, novel techniques for cancer treatment are the need of the day. Nowadays, nanotechnology is of great interest for its applications as diagnostic tools, theragnostic, contrasting agents, and vehicles for delivering drugs. Nanoparticles (NPs) are made up of biocompatible and biodegradable polymers that improve the pharmacokinetic and pharmacodynamic properties of drugs, reduce side effects, improve stability, prolong the release of drug, and reduce the dosing frequency. Poly (lactic-co-glycolic acid) (PLGA) is FDA-approved synthetic polymer which can be used to formulate NPs that can be targeted to a specific site for the safe and effective delivery of drugs. PLGA-based NPs can be used for a variety of cancer therapies including tumor-targeted drug delivery, gene therapy, hyperthermia, and photodynamic therapy. This article discusses the method of preparation, characterization, encapsulation of chemotherapeutic drugs, effect of physicochemical properties of PLGA- based NPs, and how we can exploit these aspects through various methods of preparation for drug loading, biodistribution, target specificity, and their use in cancer treatment. Along with these targeting strategies, gene therapy, cancer immunotherapy, and various applications have also been discussed. This article also aims to discuss the incorporation of diagnostic tools and therapeutic moiety in one versatile formulation of PLGA-NPs and the difficulties faced in translating this promising tool to clinical use.

Baicalein Loaded Crown Ether-mPEG-PLGA Micelle Drug Delivery System for Increased Breast Cancer Treatment: Preparation, Characterization, In-Vitro and In-Vivo Evaluations

Due to low aqueous solubility and poor bioavailability of the flavone baicalein (BIC), a nano-micelle of delivery system was developed. Preparation of BIC-loaded crown ether-mPEG-PLGA micelle (BCPP-M) was performed via thin-film hydration method. Characterization of micellar excipients was accomplished with 1H NMR, while evaluation of the optimal BCPP-M formulation was appropriately carried out through zeta potential (ZP), size of particles (PS), efficiency of encapsulation (EE) and capacity of drug loading (DL). We evaluated BIC release In-Vitro and profile of In-Vivo pharmacokinetics. Evaluation of the anti-breast cancer property of BCPP-M using MCP-7 cells cytotoxicity and mice model was performed. Particles of BCPP-M were homogenously and spherically shaped with smaller average PS, coupled with higher EE and DL, good stability and polydispersity index (PDI). The accumulative release of BCPP-M was obviously higher than free-BIC. Significantly, oral biological availability of BCPP-M was improved comparable to free BIC. Besides, half maximum inhibitory concentration (IC50) of BCPP-M in MCP-7 cells was lower than free-BIC. Animal experiments also showed targeting, long circulation and antitumor potential of BCPP-M. Successful incorporation of BIC into long-acting and targeting micellar system could have enhanced solubility in aqueous media, oral In-Vivo availability and antitumor property of BIC.

Preparation and characterization of flexible furosemide-loaded biodegradable microneedles for intradermal drug delivery

Transdermal drug delivery systems are a useful and minimally invasive alternative to other drug administration routes. Biodegradable polymeric microneedles (MNs) are widely used in controlled-release drug delivery due to their tunable properties and ease of patient self-administration. Polylactic-co-glycolic acid (PLGA) is often used for sustained drug release owing to special intrinsic properties including biocompatibility and biodegradability, which offer excellent applicability in preparing MNs. Congestive heart failure (CHF) is characterized by fluid overload during acute exacerbation, necessitating frequent patient hospitalization for continuous intravenous (i.v.) diuretic therapy. In the present study, we incorporated furosemide (FUR) as a model drug into flexible PLGA MN skin patches for potential intradermal delivery to overcome the limitations associated with i.v. diuresis. The MNs were fabricated by a casting-mold technique and consisted of two main parts, PLGA needle tips loaded with varying concentrations of FUR and a flexible backing layer comprising sodium alginate and glycerol. MN formulations were characterized by SEM and exhibited a uniform pyramidal shape. The measured surface pH of all samples suggested that no skin irritation is expected upon application. High encapsulation efficiency was obtained for FUR-MN formulations in which a decrease was noted as the FUR/PLGA ratio decreased. Drug loading content ranged from 19.1 ± 1% to 28.9 ± 1.4%. Successful insertion of MNs into a Parafilm® skin simulant model suggested that MNs will easily penetrate the skin's outermost layer, the stratum corneum, and will permit intradermal delivery of FUR. The MNs were further characterized by analytical methods. Finally, the MNs exhibited an initial burst release followed by a sustained release of FUR. Self-administered FUR-MNs can open new avenues to overcome i.v. drip limitations and increase patient compliance.

Amomum longiligulare polysaccharide 1- PLGA nanoparticle promotes the immune activities of T lymphocytes and dendritic cells

Amomum longiligulare polysaccharide 1 (ALP1) was extracted from Amomum longiligulare T.L. Wu fruits and the poly (lactic-co-glycolic acid) nanoparticle enveloping ALP1 (ALPP) showed a good promoting effect on the activation of macrophages in our previous study. To further understand the immunomodulatory property of ALPP, the effect of ALPP on T lymphocytes and dendritic cells was investigated in the present study. The proliferation rates of chicken T lymphocytes and chicken bone marrow dendritic cells (chBM-DCs) that were treated with ALP1 or ALPP were determined by using MTT method. Meanwhile, the relative mRNA levels of cytokines from T lymphocytes and surface molecules of chBM-DCs were determined by using qRT-PCR method. In addition, the drug uptake capacity of chBM-DCs was also tested. As a result, the promoting effect on the proliferation of T lymphocytes and the Th1-type immune response of ALPP was better than that of ALP1. In addition, ALPP was much more effectively swallowed by chBM-DCs so that its promoting effect on the proliferation and maturation of chBM-DCs was higher than that of ALP1. To conclude, ALPP had a stronger immunomodulatory activity than ALP1, and showed the potential to become a new type of immune booster.

Dual-jet electrospun PDLGA/PCU nonwovens as promising mesh implant materials with controlled release of sirolimus and diclofenac

Dual-jet electrospinning was employed to produce two-component, partially degradable drug releasing nonwovens with interlacing of poly(D,L-lactide-co-glycolide) (PDLGA) and different poly(carbonate urethanes) (PCUs). Diclofenac sodium and sirolimus were released simultaneously from the copolyester carrier. The research focused on determining of release profiles of drugs, depending on the hydrophilicity of introduced PCU nanofibers. The influence of drugs incorporation on the hydrolytic degradation of the PDLGA and mechanical properties of nonwovens was also studied. Evaluation for interaction with cells in vitro was investigated on a fibroblast cell line in cytotoxicity and surface adhesion tests. Significant changes in drugs release rate, depending on the applied PCU were observed. It was also noticed, that hydrophilicity of drugs significantly influenced the hydrolytic degradation mechanism and surface erosion of the PDLGA, as well as the tensile strength of nonwovens. Tests carried out on cells in an in vitro experiment showed that introduction of sirolimus caused a slight reduction in the viability of fibroblasts as well as a strong limitation in their capability to colonize the surface of fibers. Due to improvement of mechanical strength and the ability to controlled drugs release, the obtained material may be considered as prospect surgical mesh implant in the treatment of hernia.