Hydrogels: 3D Drug Delivery Systems for Nanoparticles and Extracellular Vesicles

Advantages and therapeutic applications of different semisolids as vehicles for nano-based systems

The aim of this review is to highlight the role of semisolid systems as vehicles for nanovesicles and nanoparticles. In general, nanotechnology plays a critical role in facilitating the delivery of therapeutic agents to their active sites, and several nanocarrier systems have been explored for the topical administration of active components. The major disadvantage of the prepared nanosystems is their low viscosity, which reduces the time needed for enough absorption and negatively affects their stability and bioavailability. The role of semisolid systems is to overcome this limitation. In conclusion, this review presents an updated summary of recent advances in the use of semisolids as vehicles for various nanosystems through comprehensive scrutiny of the types of semisolids and their advantages and their role in enhancing the absorption of nanoparticles and nanovesicles.

Pharmaceutical 3D Printing Technology Integrating Nanomaterials and Nanodevices for Precision Neurological Therapies

Pharmaceutical 3D printing, combined with nanomaterials and nanodevices, presents a transformative approach to precision medicine for treating neurological diseases. This technology enables the creation of tailored dosage forms with controlled release profiles, enhancing drug delivery across the blood-brain barrier (BBB). The integration of nanoparticles, such as poly lactic-co-glycolic acid (PLGA), chitosan, and metallic nanomaterials, into 3D-printed scaffolds improves treatment efficacy by providing targeted and prolonged drug release. Recent advances have demonstrated the potential of these systems in treating conditions like Parkinson's disease, epilepsy, and brain tumors. Moreover, 3D printing allows for multi-drug combinations and personalized formulations that adapt to individual patient needs. Novel drug delivery approaches, including stimuli-responsive systems, on-demand dosing, and theragnostics, provide new possibilities for the real-time monitoring and treatment of neurological disorders. Despite these innovations, challenges remain in terms of scalability, regulatory approval, and long-term safety. The future perspectives of this technology suggest its potential to revolutionize neurological treatments by offering patient-specific therapies, improved drug penetration, and enhanced treatment outcomes. This review discusses the current state, applications, and transformative potential of 3D printing and nanotechnology in neurological treatment, highlighting the need for further research to overcome the existing challenges.

Bioprinted Hydrogels as Vehicles for the Application of Extracellular Vesicles in Regenerative Medicine

Three-dimensional bioprinting is a new advance in tissue engineering and regenerative medicine. Bioprinting allows manufacturing three-dimensional (3D) structures that mimic tissues or organs. The bioinks used are mainly made of natural or synthetic polymers that must be biocompatible, printable, and biodegradable. These bioinks may incorporate progenitor cells, favoring graft implantation and regeneration of injured tissues. However, the natures of biomaterials, bioprinting processes, a lack of vascularization, and immune responses are factors that limit the viability and functionality of implanted cells and the regeneration of damaged tissues. These limitations can be addressed by incorporating extracellular vesicles (EV) into bioinks. Indeed, EV from progenitor cells may have regenerative capacities, being similar to those of their source cells. Therefore, their combinations with biomaterials can be used in cell-free therapies. Likewise, they can complement the manufacture of bioinks by increasing the viability, differentiation, and regenerative ability of incorporated cells. Thus, the main objective of this review is to show how the use of 3D bioprinting technology can be used for the application of EV in regenerative medicine by incorporating these nanovesicles into hydrogels used as bioinks. To this end, the latest advances derived from in vitro and in vivo studies have been described. Together, these studies show the high therapeutic potential of this strategy in regenerative medicine.

Antitumor Research Based on Drug Delivery Carriers: Reversing the Polarization of Tumor-Associated Macrophages

The development of malignant tumors is a complex process that involves the tumor microenvironment (TME). An immunosuppressive TME presents significant challenges to current cancer therapies, serving as a key mechanism through which tumor cells evade immune detection and play a crucial role in tumor progression and metastasis. This impedes the optimal effectiveness of immunotherapeutic approaches, including cytokines, immune checkpoint inhibitors, and cancer vaccines. Tumor-associated macrophages (TAMs), a major component of tumor-infiltrating immune cells, exhibit dual functionalities: M1-like TAMs suppress tumorigenesis, while M2-like TAMs promote tumor growth and metastasis. Consequently, the development of various nanocarriers aimed at polarizing M2-like TAMs to M1-like phenotypes through distinct mechanisms has emerged as a promising therapeutic strategy to inhibit tumor immune escape and enhance antitumor responses. This Review covers the origin and types of TAMs, common pathways regulating macrophage polarization, the role of TAMs in tumor progression, and therapeutic strategies targeting TAMs, aiming to provide a comprehensive understanding and guidance for future research and clinical applications.

Challenges and considerations in liposomal hydrogels for the treatment of infection

INTRODUCTION

Liposomal hydrogels are novel drug delivery systems that comprise preformed liposomes incorporated in hydrogels destined for mostly localized drug therapy, herewith antimicrobial therapy. The formulation benefits from versatility of liposomes as lipid-based nanocarriers that enable delivery of various antimicrobials of different lipophilicities, and secondary vehicle, hydrogel, that assures better retention time of formulation at the infection site. Especially in an era of alarming antimicrobial resistance, efficient localized antimicrobial therapy that avoids systemic exposure of antimicrobial and related side effects is crucial.

AREAS COVERED

We provide an overview of liposomal hydrogels that were developed for superior delivery of antimicrobials at different infections sites, with focus on skin and vaginal infections. The review summarizes the challenges of infection site and most common infection-causing pathogens and offers commentary on most relevant features the formulation needs to optimize to increase the therapy outcome. We discuss the impact of liposomal composition, size, and choice of polymer-forming hydrogel on antimicrobial outcome based on the literature overview and own experience in the field.

EXPERT OPINION

Liposomal hydrogels offer improved therapy outcome in localized antimicrobial therapy. By fine-tuning of liposomal as well as hydrogel properties, formulations with superior performance can be optimized targeting specific infection site.

Engineered Extracellular Vesicles as a New Class of Nanomedicine

Extracellular vesicles (EVs) are secreted from biological cells and contain many molecules with diagnostic values or therapeutic functions. There has been great interest in academic and industrial communities to utilize EVs as tools for diagnosis or therapeutics. In addition, EVs can also serve as delivery vehicles for therapeutic molecules. An indicator of the enormous interest in EVs is the large number of review articles published on EVs, with the focus ranging from their biology to their applications. An emerging trend in EV research is to produce and utilize "engineered EVs", which are essentially the enhanced version of EVs. EV engineering can be conducted by cell culture condition control, genetic engineering, or chemical engineering. Given their nanometer-scale sizes and therapeutic potentials, engineered EVs are an emerging class of nanomedicines. So far, an overwhelming majority of the research on engineered EVs is preclinical studies; there are only a very small number of reported clinical trials. This Review focuses on engineered EVs, with a more specific focus being their applications in therapeutics. The various approaches to producing engineered EVs and their applications in various diseases are reviewed. Furthermore, in vivo imaging of EVs, the mechanistic understandings, and the clinical translation aspects are discussed. The discussion is primarily on preclinical studies while briefly mentioning the clinical trials. With continued interdisciplinary research efforts from biologists, pharmacists, physicians, bioengineers, and chemical engineers, engineered EVs could become a powerful solution for many major diseases such as neurological, immunological, and cardiovascular diseases.

Blended ƙ-carrageenan and xanthan gum hydrogel containing ketoprofen-loaded nanoemulsions: Design, characterization, and evaluation in an animal model of rheumatoid arthritis

This study reports the preparation of hydrogels (HG) made with xanthan gum (XG) and ƙ-carrageenan (KC) polysaccharides containing ketoprofen (KET)-loaded nanoemulsions (NK) and their evaluation in a rheumatoid arthritis (RA) model. The nano-based HGs exhibited nanometric-sized droplets (~ 100 nm), an acidic pH (5.10-6.83), drug content above 85%, a suitable spreadability factor, and pseudoplastic flow behavior. The most promising blend (HGCX 2:1) demonstrated sustained KET release, reaching 81.44 ± 6.11% after 5 h, and superior drug concentration in the skin layers (237.91 ± 41.0 µg/g). The formulation was selected due to its enhanced bioadhesiveness, with the HG-NK formulation showing the highest bioadhesion force and occlusion factor. RA was induced by complete Freund's adjuvant (CFA) intraplantar injection into the left hind paw of male and female Swiss mice. Treatments with HGs were applied to the animals' dorsal region for 7 days. Notably, HG-NK demonstrated remarkable efficacy, reversing mechanical sensitivity in male mice and significantly reducing thermal sensitivity in both genders. Moreover, HG-NK provided a significant reduction in paw edema (52-fold in males, 27-fold in females) and inflammatory markers, such as myeloperoxidase activity (32-fold in males, 14-fold in females) and lipid peroxidation (2.5-fold in males, twofold in females). The formulation also promoted greater permeation of KET across the skin. These findings underscore the significant reduction in inflammatory markers by the HG-NK formulation, highlighting its potent anti-inflammatory effects and potential as a promising therapeutic strategy for managing RA.

Innovative approaches in lung tissue engineering: the role of exosome-loaded bioscaffolds in regenerative medicine

Lung diseases account for over four million premature deaths every year, and experts predict that this number will increase in the future. The top cause of death globally is diseases which include conditions like lung cancer asthma and COPD. Treating severe acute lung injury is a complex task because lungs struggle to heal themselves in the presence of swelling inflammation and scarring caused by damage, to the lung tissues. Though achieving lung regeneration, in controlled environments is still an ambition; ongoing studies are concentrating on notable progress, in the field of lung tissue engineering and methods for repairing lung damage. This review delves into methods, for regenerating lungs with a focus on exosome carry bioscaffolds and mesenchymal stem cells among others. It talks about how these new techniques can help repair lung tissue and improve lung function in cases of damage. Also noted is the significance of ex vivo lung perfusion (EVLP), for rejuvenating donor lungs and the healing properties of exosomes in supporting lung regeneration.

Multifunctional hydrogel-based engineered extracellular vesicles delivery for complicated wound healing

The utilization of extracellular vesicles (EVs) in wound healing has been well-documented. However, the direct administration of free EVs via subcutaneous injection at wound sites may result in the rapid dissipation of bioactive components and diminished therapeutic efficacy. Functionalized hydrogels provide effective protection, as well as ensure the sustained release and bioactivity of EVs during the wound healing process, making them an ideal candidate material for delivering EVs. In this review, we introduce the mechanisms by which EVs accelerate wound healing, and then elaborate on the construction strategies for engineered EVs. Subsequently, we discuss the synthesis strategies and application of hydrogels as delivery systems for the sustained release of EVs to enhance complicated wound healing. Furthermore, in the face of complicated wounds, functionalized hydrogels with specific wound microenvironment regulation capabilities, such as antimicrobial, anti-inflammatory, and immune regulation, used for loading engineered EVs, provide potential approaches to addressing these healing challenges. Ultimately, we deliberate on potential future trajectories and outlooks, offering a fresh viewpoint on the advancement of artificial intelligence (AI)-energized materials and 3D bio-printed multifunctional hydrogel-based engineered EVs delivery dressings for biomedical applications.

Application of 32 factorial design for loratadine-loaded nanosponge in topical gel formulation: comprehensive in-vitro and ex vivo evaluations

Loratadine (LoR) is a highly lipophilic and practically insoluble in water, hence having a low oral bioavailability. As it is formulated as topical gel, it competitively binds with the receptors, thus reducing the side-effects. The objective of this study was to prepare LoR loaded nanosponge (LoR-NS) in gel for topical delivery. Nine different formulations of emulsion were prepared by solvent evaporation method with polyvinyl alcohol (PVA), ethyl cellulose (EC), and dichloromethane (DCM). Based on 32 Full Factorial Design (FFD), optimization was carried out by varying the concentration of LOR:EC ratio and stirring rate. The preparations were subjected for the evaluation of particle size (PS), in vitro release, zeta potential (ZP) and entrapment efficiency (EE). The results revealed that the NS dispersion was nanosized with sustained release profiles and significant PS. The optimised formulation was formulated and incorporated into carbopol 934P hydrogel. The formulation was then examined to surface morphological characterizations using scanning electron microscopy (SEM) which depicted spherical NS. Stability studies, undertaken for 2 months at 40 ± 2 °C/75 ± 5% RH, concluded to the stability of the formulation. The formulation did not cause skin irritation. Therefore, the prepared NS hydrogel proved to be a promising applicant for LoR as a novel drug delivery system (NDDS) for safe, sustained and controlled topical application.

Photo-Controllable Smart Hydrogels for Biomedical Application: A Review

Nowadays, smart hydrogels are being widely studied by researchers because of their advantages such as simple preparation, stable performance, response to external stimuli, and easy control of response behavior. Photo-controllable smart hydrogels (PCHs) are a class of responsive hydrogels whose physical and chemical properties can be changed when stimulated by light at specific wavelengths. Since the light source is safe, clean, simple to operate, and easy to control, PCHs have broad application prospects in the biomedical field. Therefore, this review timely summarizes the latest progress in the PCHs field, with an emphasis on the design principles of typical PCHs and their multiple biomedical applications in tissue regeneration, tumor therapy, antibacterial therapy, diseases diagnosis and monitoring, etc. Meanwhile, the challenges and perspectives of widespread practical implementation of PCHs are presented in biomedical applications. This study hopes that PCHs will flourish in the biomedical field and this review will provide useful information for interested researchers.

Unraveling the Multifaceted Roles of Extracellular Vesicles: Insights into Biology, Pharmacology, and Pharmaceutical Applications for Drug Delivery

Extracellular vesicles (EVs) are nanoparticles released from various cell types that have emerged as powerful new therapeutic option for a variety of diseases. EVs are involved in the transmission of biological signals between cells and in the regulation of a variety of biological processes, highlighting them as potential novel targets/platforms for therapeutics intervention and/or delivery. Therefore, it is necessary to investigate new aspects of EVs' biogenesis, biodistribution, metabolism, and excretion as well as safety/compatibility of both unmodified and engineered EVs upon administration in different pharmaceutical dosage forms and delivery systems. In this review, we summarize the current knowledge of essential physiological and pathological roles of EVs in different organs and organ systems. We provide an overview regarding application of EVs as therapeutic targets, therapeutics, and drug delivery platforms. We also explore various approaches implemented over the years to improve the dosage of specific EV products for different administration routes.

Polysaccharide hydrogel platforms as suitable carriers of liposomes and extracellular vesicles for dermal applications

Lipid-based nanocarriers have been extensively investigated for their application in drug delivery. Particularly, liposomes are now clinically established for treating various diseases such as fungal infections. In contrast, extracellular vesicles (EVs) - small cell-derived nanoparticles involved in cellular communication - have just recently sparked interest as drug carriers but their development is still at the preclinical level. To drive this development further, the methods and technologies exploited in the context of liposome research should be applied in the domain of EVs to facilitate and accelerate their clinical translation. One of the crucial steps for EV-based therapeutics is designing them as proper dosage forms for specific applications. This review offers a comprehensive overview of state-of-the-art polysaccharide-based hydrogel platforms designed for artificial and natural vesicles with application in drug delivery to the skin. We discuss their various physicochemical and biological properties and try to create a sound basis for the optimization of EV-embedded hydrogels as versatile therapeutic avenues.

Engineering of Trophoblast Extracellular Vesicle-Delivering Hydrogels for Localized Tolerance Induction in Cell Transplantation

Purpose

The need for chronic systemic immunosuppression, which presents a host of acute risks to transplantation patients, remains the primary limitation for the translation of many cell therapies, such as insulin secreting cells for the treatment of type 1 diabetes. Trophoblasts are the professional tolerogenic cells of the placenta, and they secrete a range of soluble factors to induce antigen specific tolerance toward allogeneic fetal tissue during pregnancy, including extracellular vesicles. Here we develop a trophoblast extracellular vesicle-delivering hydrogel designed for sustained, localized tolerogenic factor delivery within a transplant site to induce localized tolerance toward cell grafts.

Methods

We engineer a synthetic poly(ethylene glycol)-based hydrogel system to tether extracellular vesicles for sustained delivery, and compare this system to passive vesicle entrapment within an alginate hydrogel system. We characterize trophoblast extracellular vesicles for size and morphology, and evaluate vesicle tolerogenic protein content via proteomic analysis. We validate the retention and tethering of extracellular vesicles within the hydrogel systems via scanning electron and stimulated emission depletion microscopy, and measure vesicle release rate over time. Finally, we evaluate trophoblast extracellular vesicle influence on natural killer cell activation in vitro.

Results

We isolated trophoblast extracellular vesicles and proteomics confirmed the presence of tolerogenic factors. We confirmed the presence of extracellular vesicles within hydrogel delivery vehicles, and synthetic hydrogels extended extracellular vesicle release relative to a passive hydrogel system. Finally, extracellular vesicles reduced natural killer cell activation in vitro, confirming the tolerogenic potential of hydrogel-delivered extracellular vesicles.

Conclusions

This tolerogenic extracellular vesicle-delivering hydrogel platform designed for delivery within a transplant site could serve as an alternative to systemic immunosuppression in cell transplantation, potentially reducing the risks associated with cell therapies and widening the eligible patient population.

Extracellular vesicles and their cells of origin: Open issues in autoimmune diseases

The conventional therapeutic approaches to treat autoimmune diseases through suppressing the immune system, such as steroidal and non-steroidal anti-inflammatory drugs, are not adequately practical. Moreover, these regimens are associated with considerable complications. Designing tolerogenic therapeutic strategies based on stem cells, immune cells, and their extracellular vesicles (EVs) seems to open a promising path to managing autoimmune diseases' vast burden. Mesenchymal stem/stromal cells (MSCs), dendritic cells, and regulatory T cells (Tregs) are the main cell types applied to restore a tolerogenic immune status; MSCs play a more beneficial role due to their amenable properties and extensive cross-talks with different immune cells. With existing concerns about the employment of cells, new cell-free therapeutic paradigms, such as EV-based therapies, are gaining attention in this field. Additionally, EVs' unique properties have made them to be known as smart immunomodulators and are considered as a potential substitute for cell therapy. This review provides an overview of the advantages and disadvantages of cell-based and EV-based methods for treating autoimmune diseases. The study also presents an outlook on the future of EVs to be implemented in clinics for autoimmune patients.

Characteristics of Mitomycin C-Loaded Peptide Hydrogel In Vitro and Antiscarring Effects in Rat Ocular Injury Model

Purpose: To investigate the characteristics of sustained drug release systems established by an arginine-glycine-aspartic acid (RGD) peptide hydrogel and mitomycin C (MMC) in vitro, and verify their antiscar effects in rat ocular injury model. Methods: Low, medium, and high loading doses of MMC were added to 5 mL 0.25%, 0.5%, and 1% wt RGD peptide hydrogel, respectively, to prepare 9 ratios of MMC-RGD systems. Drug release characteristics of the systems in phosphate-buffered saline solution were investigated by plotting the drug release curves and fitting them with mathematical models in OriginPro8.0 software. Appropriate ratios of MMC-RGD systems were selected as treatment in rat ocular injury model. Scar formation was observed by Masson staining and immunohistochemical staining with alpha-smooth muscle actin (α-SMA) and fibronectin (FN). Results: Nine ratios of MMC-RGD systems could release drug slowly. The maximum drug release proportions of all systems were >80%, and the time to maximum release proportions statistically prolonged with the increase of drug loading. Fitting with mathematical models indicated that the mechanisms of drug release were mainly Fick diffusion at early stage and Anomalous Transport at later stage. Systems of 1% wt RGD hydrogel were evaluated in animal experiments, which could inhibit hyperplasia of collagen and expression of α-SMA and FN. Conclusions: The RGD peptide hydrogel could be used as the carrier of MMC to establish sustained drug release system, which could inhibit scar formation after rat's ocular injury.

Injectable hydrogels for sustained delivery of extracellular vesicles in cartilage regeneration

Extracellular vesicles (EVs) are a population of small vesicles secreted by essentially all cell types, containing a wide variety of biological macromolecules. Due to their intrinsic capabilities for efficient intercellular communication, they are involved in various aspects of cellular functioning. In the past decade, EVs derived from stem cells attracted interest in the field of regenerative medicine. Owing to their regenerative properties, they have great potential for use in tissue repair, in particular for tissues with limited regenerative capabilities such as cartilage. The maintenance of articular cartilage is dependent on a precarious balance of many different components that can be disrupted by the onset of prevalent rheumatic diseases. However, while cartilage is a tissue with strong mechanical properties that can withstand movement and heavy loads for years, it is virtually incapable of repairing itself after damage has occurred. Stem cell-derived EVs (SC-EVs) transport regenerative components such as proteins and nucleic acids from their parental cells to recipient cells, thereby promoting cartilage healing. Many possible pathways through which SC-EVs execute their regenerative function have been reported, but likely there are still numerous other pathways that are still unknown. This review discusses various preclinical studies investigating intra-articular injections of free SC-EVs, which, while often promoting chondrogenesis and cartilage repair in vivo, showed a recurring limitation of the need for multiple administrations to achieve sufficient tissue regeneration. Potentially, this drawback can be overcome by making use of an EV delivery platform that is capable of sustainably releasing EVs over time. With their remarkable versatility and favourable chemical, biological and mechanical properties, hydrogels can facilitate this release profile by encapsulating EVs in their porous structure. Ideally, the optimal delivery platform can be formed in-situ, by means of an injectable hydrogel that can be administered directly into the affected joint. Relevant research fulfilling these criteria is discussed in detail, including the steps that still need to be taken before injectable hydrogels for sustained delivery of EVs can be applied in the context of cartilage regeneration in the clinic.

Extracellular Vesicle-Based Hydrogels for Wound Healing Applications

Hydrogels and extracellular vesicle-based therapies have been proposed as emerging therapeutic assets in wound closure. The combination of these elements has given good results in managing chronic and acute wounds. The intrinsic characteristics of the hydrogels in which the extracellular vesicles (EVs) are loaded allow for overcoming barriers, such as the sustained and controlled release of EVs and the maintenance of the pH for their conservation. In addition, EVs can be obtained from different sources and through several isolation methods. However, some barriers must be overcome to transfer this type of therapy to the clinic, for example, the production of hydrogels containing functional EVs and identifying long-term storage conditions for EVs. The aim of this review is to describe the reported EV-based hydrogel combinations, along with the obtained results, and analyze future perspectives.

From Promise to Reality: Bioengineering Strategies to Enhance the Therapeutic Potential of Extracellular Vesicles

Extracellular vesicles (EVs) have been the focus of great attention over the last decade, considering their promising application as next-generation therapeutics. EVs have emerged as relevant mediators of intercellular communication, being associated with multiple physiological processes, but also in the pathogenesis of several diseases. Given their natural ability to shuttle messages between cells, EVs have been explored both as inherent therapeutics in regenerative medicine and as drug delivery vehicles targeting multiple diseases. However, bioengineering strategies are required to harness the full potential of EVs for therapeutic use. For that purpose, a good understanding of EV biology, from their biogenesis to the way they are able to shuttle messages and establish interactions with recipient cells, is needed. Here, we review the current state-of-the-art on EV biology, complemented by representative examples of EVs roles in several pathophysiological processes, as well as the intrinsic therapeutic properties of EVs and paradigmatic strategies to produce and develop engineered EVs as next-generation drug delivery systems.

The use of natural gums to produce nano-based hydrogels and films for topical application

Natural gums are a source of biopolymeric materials with a wide range of applications for multiple purposes. These polysaccharides are extensively explored due to their low toxicity, gelling and thickening properties, and bioadhesive potential, which have sparked interest in researchers given their use in producing pharmaceutic dosage forms compared to synthetic agents. Hence, gums can be used as gelling and film-forming agents, which are suitable platforms for topical drug administration. Additionally, recent studies have demonstrated the possibility of obtaining nanocomposite materials formed by a polymeric matrix of gums associated with nanoscale carriers that have shown superior drug delivery performance and compatibility with multiple administration routes compared to starting components. In this sense, research on topical natural gum-based form preparation containing drug-loaded nanocarriers was detailed and discussed herein. A special focus was devoted to the advantages achieved regarding physicochemical and mechanical features, drug delivery capacity, permeability through topical barriers, and biocompatibility of the hydrogels and polymeric films.

Insights on Development Aspects of Polymeric Nanocarriers: The Translation from Bench to Clinic

Scientists are focusing immense attention on polymeric nanocarriers as a prominent delivery vehicle for several biomedical applications including diagnosis of diseases, delivery of therapeutic agents, peptides, proteins, genes, siRNA, and vaccines due to their exciting physicochemical characteristics which circumvent degradation of unstable drugs, reduce toxic side effects through controlled release, and improve bioavailability. Polymers-based nanocarriers offer numerous benefits for in vivo drug delivery such as biocompatibility, biodegradability, non-immunogenicity, active drug targeting via surface modification, and controlled release due to their pH-and thermosensitive characteristics. Despite their potential for medicinal use, regulatory approval has been achieved for just a few. In this review, we discuss the historical development of polymers starting from their initial design to their evolution as nanocarriers for therapeutic delivery of drugs, peptides, and genes. The review article also expresses the applications of polymeric nanocarriers in the pharmaceutical and medical industry with a special emphasis on oral, ocular, parenteral, and topical application of drugs, peptides, and genes over the last two decades. The review further examines the practical, regulatory, and clinical considerations of the polymeric nanocarriers, their safety issues, and directinos for future research.

The Impact of the Matricaria chamomilla L. Extract, Starch Solution and the Photoinitiator on Physiochemical Properties of Acrylic Hydrogels

Matricaria chamomilla L. extract is well-known for its therapeutic properties; thus, it shows potential to be used to modify materials designed for biomedical purposes. In this paper, acrylic hydrogels modified with this extract were prepared. The other modifier was starch introduced into the hydrogel matrix in two forms: room-temperature solution and elevated-temperature solution. Such hydrogels were synthesized via UV radiation, while two types of photoinitiator were used: 2-hydroxy-2-methylpropiophenone or phenylbis(2,4,6-trimethylbenzoyl) phosphine oxide. The main task of performed research was to verify the impact of particular modifiers and photoinitiator on physicochemical properties of hydrogels. Studies involved determining their swelling ability, elasticity, chemical structure via FTIR spectroscopy and surface morphology via the SEM technique. Incubation of hydrogels in simulated physiological liquids, studies on the release of chamomile extract from their matrix and their biological analysis via MTT assay were also performed. It was demonstrated that all investigated variables affected the physicochemical properties of hydrogels. The modification of hydrogels with chamomile extract reduced their absorbency, decreased their thermal stability and increased the cell viability incubated with this material by 15%. Next, hydrogels obtained by using phenylbis(2,4,6-trimethylbenzoyl) phosphine oxide as a photoinitiator showed lower absorbency, more compact structure, better stability in SBF and a more effective release of chamomile extract compared to the materials prepared by using 2-hydroxy-2-methylpropiophenone. It was proved that, by applying adequate reagents, including both photoinitiator and modifiers, it is possible to obtain hydrogels with variable properties that will positively affect their application potential.

A Review of the Application of Resorcinarenes and SBA-15 in Drug Delivery

Due to the diseases that people face today, scientists dedicate a part of their research to the synthesis, characterization, and study of functional compounds for controlled drug delivery. On the one hand, resorcinarenes are macrocycles obtained by condensation reactions of resorcinol and aldehyde. They include an upper and a lower rim functioning with different groups that confer solubility to the macrocycle and favor interactions with other compounds, therefore the hydroxyl groups on the upper rim improve the formation of hydrogen bonds. Additionally, resorcinarenes feature a cavity studied for forming host-guest complexes. SBA-15, on the other hand, is a mesoporous silica characterized by ordered pores in its structure and a large surface area. As a result of its properties, it has been used for several purposes, including absorbents, drug delivery, catalysis, and environmental processes. This review shows the recent advances in synthesis methods, characterization, micelle formation, interaction with other compounds, and host-guest procedures, as well as techniques for evaluating toxicity, drug retention, and their preliminary uses in pharmacology for macrocycles, such as resorcin[4]arenes and SBA-15.

Adipose Stromal/Stem Cell-Derived Extracellular Vesicles: Potential Next-Generation Anti-Obesity Agents

Over the last decade, several compounds have been identified for the treatment of obesity. However, due to the complexity of the disease, many pharmacological interventions have raised concerns about their efficacy and safety. Therefore, it is important to discover new factors involved in the induction/progression of obesity. Adipose stromal/stem cells (ASCs), which are mostly isolated from subcutaneous adipose tissue, are the primary cells contributing to the expansion of fat mass. Like other cells, ASCs release nanoparticles known as extracellular vesicles (EVs), which are being actively studied for their potential applications in a variety of diseases. Here, we focused on the importance of the contribution of ASC-derived EVs in the regulation of metabolic processes. In addition, we outlined the advantages/disadvantages of the use of EVs as potential next-generation anti-obesity agents.