Study of the Effect of Phosvitin as a Potential Carrier on the Permeation Process of Somatotropin (STH) and Corticotropin (ACTH) from Biodegradable Polymers Used as Vehicles for STH and ACTH in Semi-Solid Formulations for Skin Application.

Phosvitin shows chelating abilities, an affinity for ACTH (corticotropin), growth factors, antioxidant properties, and acidic nature. An attempt was made to use this protein in hydrogels as a transporter of other protein substances: somatotropin (STH) and (ACTH). The aim of the study was to evaluate the effect of phosvitin on the permeation of ACTH and STH from semi-solid forms of the drug applied to the skin. Four hydrogel substrates were prepared using natural polymers: sodium alginate, methylcellulose, and starch. Based on the evaluation of physicochemical parameters, the hydrogel with the most favorable properties was selected and loaded with the active substances STH and ACTH, followed by the addition of phosvitin. A study of the permeation of STH and ACTH through the artificial cellulose membrane and through porcine skin was carried out without and with the addition of phosvitin. The effect of protein substances on rheological and textural parameters was studied. The evaluation of physicochemical parameters showed a favorable effect of STH and Phosvitin on the stability of the hydrogel with 4% methylcellulose and no effect of ACTH. All prepared formulations showed a reaction close to the natural pH of human skin. In the porcine skin permeation study, the addition of Phosvitin to the hydrogel with STH caused a slight increase in the amount of STH permeated and an increase in the time for STH to permeate porcine skin by 30 min. Phosvitin caused an increase in the amount of ACTH permeated through porcine skin almost twofold. Phosvitin may prove to be a promising permeation promoter for model protein-peptide substances when applied to the skin surface.

Two-step polyhydroxybutyrate production from hydrogenic effluent by freshwater microalgae Coelastrella sp. KKU-P1 and Acutodesmus sp. KKU-P2 under mixotrophic cultivation.

This study aimed to produce PHB using hydrogenic effluent discharged from the biohydrogen production process with freshwater microalgae including Coelastrella sp. KKU-P1, and Acutodesmus sp. KKU-P2. Batch experiments explored the influence of initial pH and hydrogenic effluent concentration, revealing optimal conditions at 10 % (v/v) effluent concentration and a pH of 6.5 for both KKU-P1 and KKU-P2. Subsequently, medium formulation and photoperiods were optimized to maximize biomass and PHB accumulation. The results showed that the optimal condition for PHB accumulation with KKU-P1 and KKU-P2 was nitrogen phosphorus (NP)-limited Bold's Basal Medium (BBM) under dark conditions. A two-step PHB accumulation in the upscale bioreactor was investigated under optimal conditions. The results showed that KKU-P1 achieved maximum PHB, protein, carbohydrate, and lipid contents of 4.57 %, 29.37 %, 24.76 %, and 13.21 %, respectively, whereas KKU-P2 achieved 6.35 %, 31.53 %, 16.16 %, and 4.77 %, respectively. Based on these findings, it appears that a mixotrophic approach under nutrient-limiting conditions is effective for PHB production in both KKU-P1 and KKU-P2 strains.

Measuring Erosion of Biodegradable Polymers in Brimonidine Drug Delivery Implants by Quantitative Proton NMR Spectroscopy (q-HNMR).

Erosion of biodegradable polymeric excipients, such as polylactic acid (PLA) and polylactic-co-glycolic acid (PLGA), is generally characterized by microbalance for the remaining mass of PLA and/or PLGA and Gel Permeation Chromatography (GPC) for molecular weight (MW) decrease. For polymer erosion studies of intravitreal sustained release brimonidine implants, however, both microbalance and GPC present several challenges. Mass loss measurement by microbalance does not have specificity for excipient polymers and drug substances. Accuracy of the remaining mass by weighing could also be low due to sample mass loss through retrieval-drying steps, especially at later drug release (DR) time points. When measuring the decrease of polymer MW by GPC, trace amounts of polymeric degradants (oligomers and/or monomers) trapped inside the implants during DR tests may not be measurable due to sensitivity limitations of the GPC detector and column MW range. Previous efforts to measure remained PLGA weight of dexamethasone micro-implants using qNMR with external calibration have been performed, however, these measurements do not account for chemical structure changes (i.e. LA to GA ratio changes from time zero) of PLGA implants during drug release tests. Here, a qNMR method with an internal standard was developed to monitor the following changes in micro-implants during drug release tests: 1. The remaining overall PLA/PLGA mass. 2. The remaining lactic acid (LA), glycolic acid (GA) unit and PLGA's lauryl ester end group percentages. 3. The trace content of PLA/PLGA oligomers as degradants retained in the implants. Unlike microbalance analysis, qNMR has both specificity for drug substance, excipient polymer, and accuracy due to minimal implant loss during sample preparation. Compared to the overall PLA/PLGA remaining mass generally monitored in erosion studies, the percentage of remaining LA, GA, and the ester end group provide more information about the microstructure change (such as hydrophobicity) of PLA/PLGA. Additionally, the qNMR method can complement GPC methods by measuring the change of remaining PLA and PLGA oligomer concentrations in brimonidine implants, with tenfold less sample and no MW cutoff. The qNMR method can be used as a sensitive tool for both polymer excipient characterization and kinetics studies of brimonidine implant erosion.

A Comparative Study on the Melt Crystallization of Biodegradable Poly(butylene succinate-co-terephthalate) and Poly(butylene adipate-co-terephthalate) Copolyesters.

As an important biodegradable and partially biobased copolyester, poly(butylene succinate-co-terephthalate) (PBST) possesses comparable thermal and mechanical properties and superior gas barrier performance when compared with poly(butylene adipate-co-terephthalate) (PBAT), but it was found to display poorer melt processability during pelletizing and injection molding. To make clear its melt crystallization behavior under rapid cooling, PBST48 and PBST44 were synthesized, and their melt crystallization was investigated comparatively with PBAT48. PBST48 showed a PBAT48-comparable melt crystallization performance at a cooling rate of 10 °C/min or at isothermal conditions, but it showed a melt crystallization ability at a cooling rate of 40 °C/min which was clearly poorer. PBST44, which has the same mass composition as PBAT48, completely lost its melt crystallization ability under the rapid cooling. The weaker chain mobility of PBST, resulting from its shorter succinate moiety, is responsible for its inferior melt crystallization ability and processability. In comparison with PBAT48, PBST48 displayed higher tensile modulus, and both PBST48 and PBST44 showed higher light transmittance. The findings in this study deepen the understanding of PBST's properties and will be of guiding significance for improving PBST's processability and application development.

The Designs and Testing of Biodegradable Energy-Absorbing Inserts for Enhanced Crashworthiness in Sports Helmets.

This article addresses manufacturing structures made via injection molding from biodegradable materials. The mentioned structures can be successfully used as energy-absorbing liners of all kinds of sports helmets, replacing the previously used expanded polystyrene. This paper is focused on injection technological tests and tensile tests (in quasi-static and dynamic conditions) of several composites based on a PLA matrix with the addition of other biodegradable softening agents, such as PBAT and TPS (the blends were prepared via melt blending using a screw extruder with mass compositions of 50:50, 30:70, and 15:85). Tensile tests showed a positive strain rate sensitivity of the mixtures and a dependence of the increase in the ratio of the dynamic to static yield stress on the increase in the share of the plastic component in the mixture. Technological tests showed that increasing the amount of the plasticizing additive by 35% (from 50% to 85%) results in a decrease in the minimal thickness of the thin-walled element that can be successfully injection molded by about 32% in the case of PLA/PBAT blends (from 0.22 mm to 0.15 mm) and by about 26% in the case of PLA/TPS blends (from 0.23 mm to 0.17 mm). Next, the thin-walled elements (dimensions of 55 × 55 × 20 mm) were manufactured and evaluated using a spring-loaded drop hammer. The 60 J impact energy was tested in accordance with the EN 1078 standard. The dynamic crushing test included checking the influence of the materials' temperature (-20, 0, 20, and 40 °C) and the impact velocity. It was proven that the maximum deflection increases with increasing material temperature and an increase in the share of the plastic component in the mixture. The PLA15PBAT85 blend was selected as the most effective material in terms of its use as an energy-absorbing liner for sport helmets. Johnson-Cook and Cowper-Symonds material plasticizing models were constructed. Their use during dynamic FE simulation provided results that were in good agreement with those of the conducted experiment.

Biodegradable polymers and platelet-rich plasma causing visual impairment: a literature review.

BACKGROUND: Dermal fillers are widely used for facial rejuvenation and esthetic enhancement, offering temporary solutions for aging and volume loss. Despite their general safety, a rare but severe complication associated with these fillers is visual impairment, including blindness. This underscores the need for a thorough understanding of risks associated with various filler materials. Historical cases of blindness following filler injections date back to 1963, with increasing reports linked to the expansion of the cosmetic filler industry. While hyaluronic acid (HA) and autologous fat have been extensively studied, other fillers such as calcium hydroxylapatite and poly-l-lactic acid (PLLA) are less understood. OBJECTIVE: This systematic review aims to address gaps in the literature by providing a comprehensive overview of visual impairment caused by fillers other than HA and autologous fat. We systematically examine the prevalence, causes, clinical features, and treatment outcomes associated with these less common fillers. MATERIALS AND METHODS: A comprehensive literature search was conducted across databases including PubMed, Scopus, and Google Scholar using terms related to visual impairment and dermal fillers. Studies published between 2014 and 2021, including observational studies and case reports, were included. Studies were selected based on predefined inclusion and exclusion criteria, and a PRISMA flow diagram was used to illustrate the study selection process. RESULTS: The review identifies and summarizes cases of visual impairment associated with calcium hydroxylapatite, poly-d,l-lactic acid (PDLLA), and PLLA fillers. Key findings reveal that visual impairment following these fillers is rare but can occur suddenly or within a few days of the procedure. Cases of delayed onset up to two weeks are also noted, emphasizing the need for extended post-procedure monitoring. DISCUSSION: The review highlights unique insights into the risks associated with non-HA fillers, such as the heightened risk in the periorbital region and other facial areas. It explores mechanisms of complications, including retrograde flow of emboli leading to retinal ischemia. The discussion also covers emergency protocols and preventative measures, providing valuable guidance for managing and mitigating risks. CONCLUSIONS: Visual impairment caused by fillers other than HA and autologous fat, while rare, represents a serious complication that requires careful attention. This review contributes new perspectives on the differential risks of various fillers, symptom onset variability, and anatomical risk factors. Emphasizing the importance of proper patient selection, technique, and monitoring, it calls for further research to better understand and prevent these complications, ultimately aiming for safer and more effective use of soft-tissue fillers.

Advanced Biomaterials Derived from Functional Polyphosphoesters: Synthesis, Properties, and Biomedical Applications.

Polyphosphoesters (PPEs) represent an innovative class of biodegradable polymers, with the phosphate ester serving as the core repeating unit of their polymeric backbone. Recently, biomaterials derived from functionalized PPEs have garnered significant interest in biomedical applications because of their commendable biocompatibility, biodegradability, and the capacity for functional modification. This review commences with a brief overview of synthesis methodologies and the distinctive properties of PPEs, including thermoresponsiveness, degradability, stealth effect, and biocompatibility. Subsequently, the review delves into the latest applications of PPEs-based nanocarriers for drug or gene delivery and PPEs-based polymeric prodrugs and scaffolds in the biomedical field, presenting several illustrative examples for each application. By encapsulating the advancements of recent years, this review aims to offer an enhanced understanding and serve as a reference for the synthesis and biomedical applications of functional PPEs.

Developing multifunctional cellulose derivatives for environmental and biomedical applications: Insights into modification processes and advanced material properties.

The growing bioeconomic demand for lightweight, eco-friendly materials with functional versatility and competitive mechanical properties drives the resurgence of cellulose as a sustainable scaffold for various applications. This review comprehensively scrutinizes current progressions in cellulose functional materials (CFMs), concentrating on their structure-property connections. Significant modification methods, including cross-linking, grafting, and oxidation, are discussed together with preparation techniques categorized by cellulose sources. This review article highlights the extensive usage of modified cellulose in various industries, particularly its potential in optical and toughening applications, membrane production, and intelligent bio-based systems. Prominence is located on low-cost procedures for developing biodegradable polymers and the physical-chemical characteristics essential for biomedical applications. Furthermore, the review explores the role of cellulose derivatives in smart packaging films for food quality monitoring and deep probes into cellulose's mechanical, thermal, and structural characteristics. The multifunctional features of cellulose derivatives highlight their worth in evolving environmental and biomedical engineering applications.

Water-Templated Growth of Interfacial Superglue Polymers for Tunable Thin Films and In Situ Fluid Encapsulation.

Thin polymer films (TPFs) are indispensable elements in numerous technologies ranging from liquid encapsulation to biotechnology to electronics. However, their production typically relies on wet chemistry involving organic solvents or chemical vapor deposition, necessitating elaborate equipment and often harsh conditions. Here, an eco-friendly, fast, and facile synthesis of water-templated interfacial polymers based on cyanoacrylates (superglues, CAs) that yield thin films with tailored properties is demonstrated. Specifically, by exposing a cationic surfactant-laden water surface to cyanoacrylate vapors, surfactant-modulated anionic polymerization produces a manipulable thin polymer film with a thickness growth rate of 8 nm min-1. Furthermore, the shape and color of the film are precisely controlled by the polymerization kinetics, wetting conditions, and/or exposure to patterned light. Using various interfaces as templates for film growth, including the free surface of drops and soap bubbles, the developed method advantageously enables in situ packaging of chemical and biological cargos in liquid phase as well as the encapsulation of gases within solidified bubbles. Simple, versatile, and biocompatible, this technology constitutes a potent platform for programmable coating and soft/smart encapsulation of fluids.

Enhancing the Biodegradability, Water Solubility, and Thermal Properties of Polyvinyl Alcohol through Natural Polymer Blending: An Approach toward Sustainable Polymer Applications.

The escalating environmental crisis posed by single-use plastics underscores the urgent need for sustainable alternatives. This study provides an approach to introduce biodegradable polymer blends by blending synthetic polyvinyl alcohol (PVA) with natural polymers-corn starch (CS) and hydroxypropyl methylcellulose (HPMC)-to address this challenge. Through a comprehensive analysis, including of the structure, mechanical strength, water solubility, biodegradability, and thermal properties, we investigated the enhanced performance of PVA-CS and PVA-HPMC blends over conventional polymers. Scanning electron microscopy (SEM) findings of pure PVA and its blends were studied, and we found a complete homogeneity between the PVA and both types of natural polymers in the case of a high concentration of PVA, whereas at lower concentration of PVA, some granules of CS and HMPC appear in the SEM. Blending corn starch (CS) with PVA significantly boosts its biodegradability in soil environments, since adding starch of 50 w/w duplicates the rate of PVA biodegradation. Incorporating hydroxypropyl methylcellulose (HPMC) with PVA not only improves water solubility but also enhances biodegradation rates, as the addition of HPMC increases the biodegradation of pure PVA from 10 to 100% and raises the water solubility from 80 to 100%, highlighting the significant acceleration of the biodegradation process and water solubility caused by HPMC addition, making these blends suitable for a wide range of applications, from packaging and agricultural films to biomedical engineering. The thermal properties of pure PVA and its blends with natural were studied using diffraction scanning calorimetry (DSC). It is found that the glass transition temperature (Tg) increases after adding natural polymers to PVA, referring to an improvement in the molecular weight and intermolecular interactions between blend molecules. Moreover, the amorphous structure of natural polymers makes the melting temperature ™ lessen after adding natural polymer, so the blends require lower temperature to remelt and be recycled again. For the mechanical properties, both types of natural polymer decrease the tensile strength and elongation at break, which overall weakens the mechanical properties of PVA. Our findings offer a promising pathway for the development of environmentally friendly polymers that do not compromise on performance, marking a significant step forward in polymer science's contribution to sustainability. This work presents detailed experimental and theoretical insights into novel polymerization methods and the utilization of biological strategies for advanced material design.

Materials based on biodegradable polymers chitosan/gelatin: a review of potential applications.

Increased mass manufacturing and the pervasive use of plastics in many facets of daily life have had detrimental effects on the environment. As a result, these worries heighten the possibility of climate change due to the carbon dioxide emissions from burning conventional, non-biodegradable polymers. Accordingly, biodegradable gelatin and chitosan polymers are being created as a sustainable substitute for non-biodegradable polymeric materials in various applications. Chitosan is the only naturally occurring cationic alkaline polysaccharide, a well-known edible polymer derived from chitin. The biological activities of chitosan, such as its antioxidant, anticancer, and antimicrobial qualities, have recently piqued the interest of researchers. Similarly, gelatin is a naturally occurring polymer derived from the hydrolytic breakdown of collagen protein and offers various medicinal advantages owing to its unique amino acid composition. In this review, we present an overview of recent studies focusing on applying chitosan and gelatin polymers in various fields. These include using gelatin and chitosan as food packaging, antioxidants and antimicrobial properties, properties encapsulating biologically active substances, tissue engineering, microencapsulation technology, water treatment, and drug delivery. This review emphasizes the significance of investigating sustainable options for non-biodegradable plastics. It showcases the diverse uses of gelatin and chitosan polymers in tackling environmental issues and driving progress across different industries.

Mineralization and microbial utilization of poly(lactic acid) microplastic in soil.

The current carbon dioxide (CO2) evolution-based standard method for determining biodegradable microplastics (MPs) degradation neglects its priming effect on soil organic matter decomposition, which misestimates their biodegradability. Here, a 13C natural abundance method was used to estimate the mineralization of poly(lactic acid) (PLA) MP in various agricultural soils, and to trace its utilization in different microbial groups. In alkaline soils, the PLA-derived CO2 emissions increased with increasing soil carbon/nitrogen (C/N) ratios, and the mineralization of PLA MP concentrations ranged from 3-33 %, whereas the CO2 evolution method probably over- or under-estimated the mineralization of PLA in alkaline soils with different soil C/N ratios. Low PLA mineralization (1-5 %) were found in the acidic soil, and the standard method largely overestimated the mineralization of PLA MP by 1.3- to 3.3-fold. Moreover, the hydrolysate of PLA MP was preferentially assimilated by Gram-negative bacteria, but Gram-positive bacterial decomposition mainly contributed to the release of PLA-derived CO2 at low MP concentrations (≤ 1 %). Overall, the 13C natural abundance method appears to be suitable for tracking the mineralization and microbial utilization of biodegradable PLA in soils, and the PLA-derived C is mainly assimilated and decomposed by bacterial groups.

Accelerated degradation testing impacts the degradation processes in 3D printed amorphous PLLA.

Additive manufacturing and electrospinning are widely used to create degradable biomedical components. This work presents important new data showing that the temperature used in accelerated tests has a significant impact on the degradation process in amorphous 3D printed poly-l-lactic acid (PLLA) fibres. Samples (c. 100 µ m diameter) were degraded in a fluid environment at 37 ° C, 50 ° C and 80 ° C over a period of 6 months. Our findings suggest that across all three fluid temperatures, the fibres underwent bulk homogeneous degradation. A three-stage degradation process was identified by measuring changes in fluid pH, PLLA fibre mass, molecular weight and polydispersity index. At 37 ° C, the fibres remained amorphous but, at elevated temperatures, the PLLA crystallised. A short-term hydration study revealed a reduction in glass transition (Tg), allowing the fibres to crystallise, even at temperatures below the dry Tg. The findings suggest that degradation testing of amorphous PLLA fibres at elevated temperatures changes the degradation pathway which, in turn, affects the sample crystallinity and microstructure. The implication is that, although higher temperatures might be suitable for testing bulk material, predictive testing of the degradation of amorphous PLLA fibres (such as those produced via 3D printing or electrospinning) should be conducted at 37 ° C.

Meniscal Allograft versus Synthetic Graft in Treatment Outcomes of Meniscus Repair: A Mini-review and Meta-analysis.

Meniscal injuries are highly correlated with osteoarthritis (OA) onset and progression. Although meniscal allograft transplantation (MAT) is a therapeutic option to restore meniscal anatomy, a shortage of donor material and the donor-derived infectious risk may be concerns in clinics. This review summarizes the literature reporting meniscus repair status in preclinical models and clinical practice using allografts or synthetic grafts. The advantages and limitations of biodegradable polymer-based meniscal scaffolds, applied in preclinical studies, are discussed. Then, the long-term treatment outcomes of patients with allografts or commercial synthetic scaffolds are compared. A total of 47 studies are included in our network meta-analysis. Compared with the meniscal allografts, the commercial synthetic products significantly improved clinical treatment outcomes in terms of the Knee Injury and Osteoarthritis Outcome Score (KOOS), Visual Analog Scale (VAS) scores, and Lysholm scores. In addition, development strategies for the next generation of novel synthetic scaffolds are proposed through optimization of structural design and fabrication, and selection of cell sources, external stimuli, and active ingredients. This review may inspire researchers and surgeons to design and fabricate clinic-orientated grafts with improved treatment outcomes.

Improving the behavior of thermoplastic starch with the addition of gum Arabic: Antibacterial, mechanical properties and biodegradability.

The incorporation of different amounts of Gum Arabic (GA) in thermoplastic starch (TPS) obtained by extrusion and subsequent thermocompression has been studied. The sheets have been characterized by means of XRD, FTIR, TGA, moisture content, SEM, mechanical properties, antimicrobial activity and biodegradability via composting. The FTIR analysis of the sheets shows the presence of ester groups, while the TGA shows the presence of new processes and a residue much higher than expected is obtained. No changes in crystallinity are observed by XRD. The inclusion of GA confers antimicrobial properties to thermoplastic starch against the Gram + and Gram - bacteria studied even at the smaller concentrations. For a low GA content (0.5 and 1 g GA/100 g TPS) a homogeneous material is observed by SEM, as well as an important increase in tensile strength, modulus and deformation at break, which are very interesting properties facing the applicability of this material in single use plastics which are in contact with food or other consumable goods. At higher contents of GA, hollows and cracks appear in the material, compromising the mechanical properties. In all cases, the inclusion of GA delays the biodegradation process in soil, which can be related to its antibacterial capacity and especially in case of GA concentrations of 2 and 5 g/100 g of TPS with lower humidity of these TPS sheets.

Development of PBS/Nano Composite PHB-Based Multilayer Blown Films with Enhanced Properties for Food Packaging Applications.

Biobased and biodegradable plastics have emerged as promising alternatives to conventional plastics offering the potential to reduce environmental impacts while promoting sustainability. This study focuses on the production of multilayer blown films with enhanced functional properties suitable for food packaging applications. Films were developed through co-extrusion in a three-layer film configuration, with Polybutylene Succinate (PBS) and Polybutylene Succinate Adipate (PBSA) as the external and internal layers, respectively. The functional layer consisted of Polyhydroxybutyrate (PHB) enhanced with nanoclays Cloisite® 30B at varying weight ratios. Films were also processed by manipulating the extruder screw speed of the functional layer to investigate its impact on the functional properties. Rheology, mechanical strength, and barrier performance were characterised to establish correlations between processing conditions and functional layer blends (Cloisite® 30B/PHB) on the properties of the resultant films. Rheological test results indicated that the system with 5% Cloisite® had the best polymer/nanofiller matrix dispersion. Mechanical and permeability tests showed that by varying the process conditions (the alteration of the thickness of the functionalized layer) resulted in an improvement in mechanical and barrier properties. Furthermore, the addition of the nanofiller resulted in a stiffening of the film with a subsequent decrease in permeability to oxygen and water vapour.

Biodegradable Conducting Polymer-Based Composites for Biomedical Applications-A Review.

In recent years, researchers have increasingly directed their focus toward the biomedical field, driven by the goal of engineering polymer systems that possess a unique combination of both electrical conductivity and biodegradability. This convergence of properties holds significant promise, as it addresses a fundamental requirement for biomedical applications: compatibility with biological environments. These polymer systems are viewed as auspicious biomaterials, precisely because they meet this critical criterion. Beyond their biodegradability, these materials offer a range of advantageous characteristics. Their exceptional processability enables facile fabrication into various forms, and their chemical stability ensures reliability in diverse physiological conditions. Moreover, their low production costs make them economically viable options for large-scale applications. Notably, their intrinsic electrical conductivity further distinguishes them, opening up possibilities for applications that demand such functionality. As the focus of this review, a survey into the use of biodegradable conducting polymers in tissue engineering, biomedical implants, and antibacterial applications is conducted.

New Polymeric Hydrogels with Cannabidiol and α-Terpineol as Potential Materials for Skin Regeneration-Synthesis and Physicochemical and Biological Characterization.

Dermatology and cosmetology currently prioritize healthy, youthful-looking skin. As a result, research is being conducted worldwide to uncover natural substances and carriers that allow for controlled release, which could aid in the battle against a variety of skin illnesses and slow the aging process. This study examined the biological and physicochemical features of novel hydrogels containing cannabidiol (CBD) and α-terpineol (TER). The hydrogels were obtained from ε-caprolactone (CL) and poly(ethylene glycol) (PEG) copolymers, diethylene glycol (DEG), poly(tetrahydrofuran) (PTHF), 1,6-diisocyanatohexane (HDI), and chitosan (CHT) components, whereas the biodegradable oligomers were synthesized using the enzyme ring-opening polymerization (e-ROP) method. The in vitro release rate of the active compounds from the hydrogels was characterized by mainly first-order kinetics, without a "burst release". The antimicrobial, anti-inflammatory, cytotoxic, antioxidant, and anti-aging qualities of the designed drug delivery systems (DDSs) were evaluated. The findings indicate that the hydrogel carriers that were developed have the ability to scavenge free radicals and impact the activity of antioxidant enzymes while avoiding any negative effects on keratinocytes and fibroblasts. Furthermore, they have anti-inflammatory qualities by impeding protein denaturation as well as the activity of proteinase and lipoxygenase. Additionally, their ability to reduce the multiplication of pathogenic bacteria and inhibit the activity of collagenase and elastase has been demonstrated. Thus, the developed hydrogel carriers may be effective systems for the controlled delivery of CBD, which may become a valuable tool for cosmetologists and dermatologists.

Citric Acid: A Nexus Between Cellular Mechanisms and Biomaterial Innovations.

Citrate-based biodegradable polymers have emerged as a distinctive biomaterial platform with tremendous potential for diverse medical applications. By harnessing their versatile chemistry, these polymers exhibit a wide range of material and bioactive properties, enabling them to regulate cell metabolism and stem cell differentiation through energy metabolism, metabonegenesis, angiogenesis, and immunomodulation. Moreover, the recent US Food and Drug Administration (FDA) clearance of the biodegradable poly(octamethylene citrate) (POC)/hydroxyapatite-based orthopedic fixation devices represents a translational research milestone for biomaterial science. POC joins a short list of biodegradable synthetic polymers that have ever been authorized by the FDA for use in humans. The clinical success of POC has sparked enthusiasm and accelerated the development of next-generation citrate-based biomaterials. This review presents a comprehensive, forward-thinking discussion on the pivotal role of citrate chemistry and metabolism in various tissue regeneration and on the development of functional citrate-based metabotissugenic biomaterials for regenerative engineering applications.

Recent Advances in the Degradability and Applications of Tissue Adhesives Based on Biodegradable Polymers.

In clinical practice, tissue adhesives have emerged as an alternative tool for wound treatments due to their advantages in ease of use, rapid application, less pain, and minimal tissue damage. Since most tissue adhesives are designed for internal use or wound treatments, the biodegradation of adhesives is important. To endow tissue adhesives with biodegradability, in the past few decades, various biodegradable polymers, either natural polymers (such as chitosan, hyaluronic acid, gelatin, chondroitin sulfate, starch, sodium alginate, glucans, pectin, functional proteins, and peptides) or synthetic polymers (such as poly(lactic acid), polyurethanes, polycaprolactone, and poly(lactic-co-glycolic acid)), have been utilized to develop novel biodegradable tissue adhesives. Incorporated biodegradable polymers are degraded in vivo with time under specific conditions, leading to the destruction of the structure and the further degradation of tissue adhesives. In this review, we first summarize the strategies of utilizing biodegradable polymers to develop tissue adhesives. Furthermore, we provide a symmetric overview of the biodegradable polymers used for tissue adhesives, with a specific focus on the degradability and applications of these tissue adhesives. Additionally, the challenges and perspectives of biodegradable polymer-based tissue adhesives are discussed. We expect that this review can provide new inspirations for the design of novel biodegradable tissue adhesives for biomedical applications.