Search Results (546)

The accelerated hydrolytic degradation of poly(L-lactide) (PLA)/magnesium (Mg) composite films was investigated to elucidate the influence of surface modification of Mg particles on the degradation behavior and characteristics of PLA composites. Accelerated degradation studies were conducted at 60 °C in a pH 7.4 phosphate-buffered solution over 7 weeks, with degradation monitored using several techniques: mass loss, water absorption, thermal analysis, and Raman spectroscopy. The results indicated that all composite films experienced more than 90% mass loss at the end of experiment; however, PLA/5MgTT and PLA/5MgPEI exhibited the highest resistance to degradation, likely due to the protective effect of the surface modification induced by thermal treatment and polyethylenimine (PEI). Notably, these characteristics did not compromise the biocompatibility or osteogenic potential of the films, which remained comparable to the control samples when tested on human bone marrow multipotent mesenchymal/stromal cells. Full article

Background/Objectives: The effect of fusidic acid on oral bacteria, especially on Gram- negative periodontopathogenic species, has not yet been investigated. This in vitro study aimed to analyze the antibacterial effect of fusidic acid alone and as an active component in electrospun poly(L-lactide-co-D/L-lactide) fiber fleeces. Methods: Minimal inhibitory concentrations (MIC) of fusidic acid and metronidazole (control) were determined for various oral bacteria. Eluates were collected from electrospun poly(L-lactide-co-D/L-lactide) fiber fleeces loaded with 10 and 20 wt% fusidic acid over a period of 28 d. Antibacterial activity was analyzed by means of a microdilution assay. Cytotoxicity was observed toward human gingival fibroblasts (HGFs). Results: All tested Gram-positive and Gram-negative oral bacteria were susceptible to fusidic acid. The lowest MIC was observed for Porphyromonas gingivalis (MIC < 0.062 µg/mL). Compared to the antibacterial activity of metronidazole, that of Porphyromonas gingivalis was suppressed by significant lower fusidic acid concentrations (p < 0.01). The eluates obtained from electrospun poly(L-lactide-co-D/L-lactide) fiber fleeces inhibited the growth of P. gingivalis, S. aureus, A. viscosus, and A. neslundii over a course of 28 days. The largest inhibition zones were detected for Porphyromonas gingivalis in case of the 20 wt% concentrations. The eluates were not cytotoxic toward HGFs. Conclusions: It was shown that fusidic acid has significant antibacterial potential. The results of the present investigation suggest that fusidic acid alone or delivered by electrospun fiber fleeces might be attractive for controlling oral pathogenic bacteria. Full article

Due to the limited regeneration of cartilage, new implant materials are needed. Biodegradable polymers poly-(D,L)-lactide-ε-caprolactone-methacrylate (LCM) and polyamid-ε-caprolactone-methacrylate (ACM) were recently established and coated with heparin, making them able to prevent blood coagulation and cartilage mineralization. The aim of this study was to analyze the suitability of LCM and ACM alone or coated with heparin (the latter are abbreviated as LCMH and ACMH, respectively) as implant material for cartilage repair. Therefore, mesenchymal stem cells were chondrogenically differentiated in 2D cultures with polymer discs. Differentiation was induced by the supplementation of cell medium with dimethyloxalylglycine, TGF-β, and BMP2. After 5 days, no increase in proinflammatory factors was observed. Cell viability declined on ACM and ACMH discs. During early chondrogenesis, SOX9 expression increased on LCM and LCMH discs, while TRPV4 expression decreased on ACMH discs. At day 20, the level of collagen type II increased on LCM, LCMH, and ACM discs, demonstrating the ability of chondrogenic development on these implants. In summary, coating with heparin showed no advantages compared to pure LCM and ACM. For cartilage repair, LCM is more suitable than ACM in this 2D in vitro model, which needs to be verified by long-term 3D models and in vivo studies. Full article

Facial aging is a multifactorial and stratified biological process characterized by progressive morphological and biochemical alterations affecting both cutaneous (Layer I) and subcutaneous (Layer II) tissues. These age-related changes manifest clinically as volume depletion, tissue ptosis, and a decline in overall skin quality. In response to these phenomena, thread lifting techniques have evolved significantly—from simple mechanical suspension methods to sophisticated bioactive platforms. Contemporary threads now incorporate biocompatible polymers and hyaluronic acid (HA), aiming not only to reposition soft tissues but also to promote dermal regeneration. This review provides a comprehensive classification and critical assessment of thread lifting materials, focusing on their chemical composition, mechanical performance, degradation kinetics, and biostimulatory potential. Particular emphasis has been given to the surface integration of HA into monofilament threads, especially with the emergence of advanced delivery systems such as NAMICA, which facilitate sustained HA release. Advanced thread materials, especially those fabricated from poly(L-lactide-co-ε-caprolactone) [P(LA/CL)], demonstrate both tensile support and regenerative efficacy. Emerging HA-covered threads exhibit synergistic bioactivity, stimulating skin remodeling. NAMICA technology represents an advancement in the field, in which HA is encapsulated within biodegradable polymer fibers to enable gradual release and enhanced dermal integration. Nonetheless, well-designed human studies are still needed to substantiate its therapeutic efficacy. Consequently, the paradigm of thread lifting is shifting from purely mechanical interventions toward biologically active systems that promote comprehensive ECM regeneration. The integration of HA into resorbable threads, especially when combined with sustained-release technologies, represents a meaningful innovation in aesthetic dermatology, meriting further preclinical and clinical evaluation. Full article

The influence of L-lactide content (between 15% and 43%) on the degradation of biodegradable polyurethanes (PUs) for tissue engineering was systematically addressed in this study. An ideal tissue scaffold should exhibit a mechanical response and degradability appropriate for the host tissue. To achieve it, polyols containing ε-caprolactone and L-lactide moieties were used, with the random distribution of lactide units disrupting the regularity, and hence the crystallinity, of poly(caprolactone) segments, facilitating their degradation. The biodegradable PUs were synthesised using these copolymers as soft segments and were characterised through various physicochemical techniques, including bioassays and water absorption measurements. It was determined that mechanical behaviour and water absorption depended significantly on molecular weight, L-lactide content in the soft segment, and the crystallinity of the hard segment. Additionally, two types of chain extenders were also evaluated: hydrolysable and non-hydrolysable. PUs based on hydrolysable chain extenders achieved higher molecular weights and exhibited better mechanical performance than their non-hydrolysable counterparts. To assess the cytocompatibility of these materials, an endothelial model was used, involving metabolic activity and DNA content analysis. The results demonstrated good cell adhesion and the absence of toxicity, confirming the viability of cell growth on the surfaces of these biodegradable PUs. The PUs developed in this study exhibited a low initial modulus and adjustable mechanical properties, highlighting their potential application in tissue engineering as biodegradable and biocompatible biomedical materials. Full article

This study investigates the impact of hydroxyapatite (HA) nanoparticles (NPs) on the cellular responses of poly(L-lactide-co-ε-caprolactone) (PLCL) scaffolds in bone tissue engineering applications. Three types of PLCL scaffolds were fabricated, varying in HANPs content. Saos-2 osteoblast-like cells (OBs) and THP-1-derived osteoclast-like cells (OCs) were co-cultured on the scaffolds, and cell proliferation was assessed using the MTS assay. The amount of double-stranded DNA (dsDNA) was quantified to evaluate cell proliferation. Expression levels of OBs and OCs markers were analyzed via quantitative polymerase chain reaction (qPCR) and the production of Collagen type I was visualized using confocal microscopy. Additionally, enzymatic activity of alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP or ACP5) was measured to assess OB and OC function, respectively. Interestingly, despite the scaffold’s structured character supporting the growth of the Saos-2 OBs and THP-1-derived OCs coculture, the incorporation of HANPs did not significantly enhance cellular responses compared to scaffolds without HANPs, except for collagen type I production. These findings suggest the need for further investigation into the potential benefits of HANPs in bone tissue engineering applications. Nevertheless, our study contributes valuable insights into optimizing biomaterial design for bone tissue regeneration, with implications for drug screening and material testing protocols. Full article

Bacterially produced poly[(R)-3-hydroxybutyrate] (P3HB) was subjected to an alcoholysis reaction to produce low-molecular-weight (M_n ≈ 10,000 g mol⁻¹) hydroxy-terminated P3HB (LMPHB). Using diethyl zinc as a catalyst, LMPHB was reacted with the cyclic monomers ε-caprolactone and l-lactide in separate ring-opening polymerization (ROP) reactions to produce PHB-b-PCL (PHBCL) and PHB-b-PLA (PHBLA) AB-type crystalline–crystalline diblock copolymers with varying PCL and PLA block lengths. ¹H NMR and GPC were used to confirm the structure of the polymers. DSC was used to measure the thermal properties as well as assessing crystallization. A single-shifting T_g for PHBLA showed the two blocks to be miscible in the melt. The TGA results indicate enhanced thermal stability over the homopolymer P3HB. A study of the crystallization was undertaken by combining WAXD, a second DSC heating regime, and POM. POM showed that the crystallization in PHBCL to be dependent on the crystallization temperature more so than PHBLA, whose composition appeared to be the more definitive factor determining the spherulitic morphology. The results informed the crystallization temperatures used in the production of the melt-crystallized thin films that were imaged using AFM. AFM images showed unique surface morphologies dependent on the diblock copolymer composition, block length, and crystallization temperature. Finally, the enzymatic degradation studies showed these unique surface morphologies to influence how these block copolymers were degraded by enzymes. Full article

We report the synthesis of highly enantiopure perdeuterated poly-L-lactic acid and poly-D-lactic acid polymers with well-defined molecular weight by polymerization of perdeuterated lactides. Enantiopure D- and L-lactic acid-d₄ monomers were synthesized from sodium pyruvate-d₃ using D- and L-lactate dehydrogenase enzymes (D-LDH and L-LDH) as biocatalysts. The reduced form of the co-enzyme nicotinamide adenine dinucleotide-d₁ (NADH-d₁) was generated in situ from the oxidized form nicotinamide adenine dinucleotide (NAD⁺) by formate dehydrogenase (FDH)-catalyzed oxidation of sodium formate-d₁ to carbon dioxide with concerted reduction of NAD⁺ to NADH-d₁. For the conversion of the perdeuterated lactic acid monomers to the corresponding lactide dimers, we developed a process for generating these compounds in the high purity needed for the final anionic ring-opening polymerization step. This method enabled the generation of a range of perdeuterated polylactic acid polymers that are highly suitable for the characterization of polymer structure and dynamics using neutron scattering, infrared and nuclear magnetic resonance spectroscopy methods that are sensitive to deuterium. Furthermore, these deuterium-labeled polymers are well-suited to the study of the biodegradation of PLA-based plastics. Full article

In modern surgery, the internal fixation plates fabricated from hydroxyapatite/poly(L-lactide) (HA/PLLA) composites encounter clinical limitations in fracture treatment due to their inadequate mechanical properties. In this work, pressure-induced flow (PIF) technique is employed to address this limitation. Under optimal processing conditions (140 °C and 250 MPa), the HA/PLLA composites exhibit an impressive flexural strength of 199.2 MPa, which is comparable to that of human cortical bone, the strongest bone tissue in the body. The tensile strength and the notched Izod impact strength are close to 84.2 MPa and 16.7 kJ/m², respectively. Meanwhile, the HA/PLLA composites develop multi-level stacked crystal layers during PIF processing, accompanied by increases in crystallinity (53.1%), crystal orientation (81.6%) and glass transition temperature (78.8 °C). After 2 months of in vitro degradation, the HA/PLLA composites processed by the PIF technique still maintain considerable flexural strength (135.3 MPa). The excellent mechanical properties of HA/PLLA composites processed by PIF technique expand their potential as an internal fixation plate. Full article

Background: Cannabidiol (CBD) is a natural compound from the Cannabis sativa L. plant, which has anti-inflammatory, anti-nociceptive, neuroprotective, and antibacterial activities. Objective: The aim of this study was to develop a sustained-release device of CBD that can provide an antibacterial effect against the Gram-positive bacteria Streptococcus mutans and Staphylococcus aureus for extended periods of time. Methods: CBD was incorporated into the biodegradable PURASORB 5010 or PURASORB 7510 DL-lactide/glycolide polymers using either dimethylsulfoxide (DMSO) or acetone as the solvent, and the dried polymer scaffolds were exposed daily to a fresh culture of bacteria. The bacterial growth was determined daily by optical density, and the metabolic activity of biofilms was determined using the MTT assay. Biofilm formation on the polymer scaffolds was visualized by HR-SEM. Its anti-inflammatory effect was determined by measuring the IL-6 release from LPS-stimulated RAW 264.7 macrophages by ELISA. Cell cytotoxicity on normal Vero epithelial cells was determined by the MTT assay. The daily release of CBD was determined by gas chromatography–mass spectrometry (GC-MS). Results: PURASORB 5010/CBD scaffolds had antibacterial activity against S. mutans UA159, S. aureus ATCC25923, and a clinical isolate of a multidrug-resistant S. aureus (MDRSA CI-M) strain for the tested period of up to 17 days. PURASORB 7510/CBD scaffolds also had antibacterial activity, but overall, it was less effective than PURASORB 5010/CBD over time. The addition of PEG400 to the copolymers significantly increased the antibacterial activity of PURASORB 7510/CBD but not of PURASORB 5010/CBD. The daily release of CBD from the polymer scaffolds was sufficient to reduce the LPS-induced IL-6 secretion from RAW 264.7 macrophages, and importantly, it was not cytotoxic to either RAW 264.7 macrophages or Vero epithelial cells. The daily release of CBD was found to be between 1.12 and 9.43 µg/mL, which is far below the cytotoxic dose of 25 µg/mL. Conclusions: The incorporation of CBD into the biodegradable PURASORB 5010 can be used to prepare sustained-release devices for medical purposes where combined antibacterial and anti-inflammatory activities are desirable. Full article

Hyaluronic acid (HA), an integral non-sulfated glycosaminoglycan, plays a pivotal role in numerous biological functions within the extracellular matrix, crucially influencing tissue hydration and cellular activities. These findings position it as a key substance in both aesthetic interventions and regenerative medicine. This study evaluated the skin remodeling efficacy of poly(L-lactide-co-ε-caprolactone) (P(LA/CL)) threads embedded with HA particles at both the microscale (P(LA/CL)-HA-micro) and nanoscale (P(LA/CL)-HA-nano) utilizing NAMICA encapsulation technology. This investigation was conducted over a six-month period in an animal model. These threads were engineered to administer HA gradually, thereby potentially augmenting the therapeutic impacts on the skin, enhancing the bioavailability of HA, and prolonging the benefits. Methodologically, the research conformed to the ARRIVE guidelines, incorporating specific inclusion and exclusion criteria for the animal model. The threads were surgically implanted, and a series of histological indicators were evaluated at scheduled intervals to determine their influence on the structural properties of the skin. The findings indicated that both P(LA/CL)-HA-micro and P(LA/CL)-HA-nano threads demonstrated potential in skin remodeling. Notably, the P(LA/CL)-HA-nano threads may have provided some advantages in enhancing certain structural aspects of the skin. The integration of micro- and nano-HA formulations through NAMICA technology might address individual limitations and synergistically promote biorevitalization in skin remodeling. Nevertheless, the intricate interactions between the biomaterials and hosted tissue underscored in this analysis suggest that additional investigations, especially using human models, are essential to fully discern the clinical implications and refine therapeutic approaches for skin remodeling via these new technologies. Full article

The exponential increase in medical waste production has increased the difficulty of waste management, resulting in higher medical waste dispersion into the environment. By employing a circular economy approach, it is possible to develop new materials by waste valorization. The employment of biodegradable and renewable agro-food, waste-derived materials may reduce the environmental impact caused by the dispersion of medical waste. In this work, tomato peel recovered cutin was blended with poly(L-lactide-co-ε-caprolactone) (PLAPCL) to develop new textiles for medical application through electrospinning. The textile fabrication process was studied by varying Cut content in the starting suspensions and by optimizing fabrication parameters. Devices with dense and porous structures were developed, and their morphological, thermal, and physical–chemical properties were evaluated through scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and Fourier transformed infrared spectroscopy. Textile material stability to γ-irradiation was evaluated through gel permeation chromatography, while its wettability, mechanical properties, and biocompatibility were analyzed through contact angle measurement, tensile test, and MTT assay, respectively. The LCA methodology was used to evaluate the environmental impact of textile production, with a specific focus on greenhouse gas (GHG) emissions. The main results demonstrated the suitability of PLAPCL–cutin blends to be processed through electrospinning and the obtained textile’s suitability to be used to develop surgical face masks or patches for wound healing. Full article

The primary challenges in the tissue engineering of small-diameter artificial blood vessels include inadequate mechanical properties and insufficient anticoagulation capabilities. To address these challenges, urea-pyrimidone (Upy)-based polyurethane elastomers (PIIU-B) were synthesized by incorporating quadruple hydrogen bonding within the polymer backbone. The synthesis process employed poly(L-lactide-ε-caprolactone) (PLCL) as the soft segment, while di-(isophorone diisocyanate)-Ureido pyrimidinone (IUI) and isophorone diisocyanate (IPDI) were utilized as the hard segment. The resulting PIIU-B small-diameter artificial blood vessel with a diameter of 4 mm was fabricated using the electrospinning technique, achieving an optimized IUI/IPDI composition ratio of 1:1. Enhanced by multiple hydrogen bonds, the vessels exhibited a robust elastic modulus of 12.45 MPa, an extracellular matrix (ECM)-mimetic nanofiber morphology, and a high porosity of 41.31%. Subsequently, the PIIU-B vessel underwent dual-functionalization with low-molecular-weight heparin and gelatin via ultraviolet (UV) crosslinking (designated as PIIU-B@LHep/Gel), which conferred superior biocompatibility and exceptional anticoagulation properties. The study revealed improved anti-platelet adhesion characteristics as well as a prolonged activated partial thromboplastin time (APTT) of 157.2 s and thrombin time (TT) of 64.2 s in vitro. Following a seven-day subcutaneous implantation, the PIIU-B@LHep/Gel vessel exhibited excellent biocompatibility, evidenced by complete integration with the surrounding peri-implant tissue, significant cell infiltration, and collagen formation in vivo. Consequently, polyurethane-based artificial blood vessels, reinforced by multiple hydrogen bonds and dual-functionalized with heparin and gelatin, present as promising candidates for vascular tissue engineering. Full article

There is currently a demand for anti-adhesive materials that are capable of preventing the formation of intra-abdominal adhesions. In this study, electrospun poly(lactide-co-glycolide) scaffolds were dip-coated in aqueous solutions of polyvinyl alcohol with concentrations of 3 wt.%, 6 wt.% and 9 wt.% to obtain a nontoxic and anti-adhesive biomedical material. The viscosities of the applied 3 wt.%, 6 wt.% and 9 wt.% polyvinyl alcohol solutions were 7.7 mPa∙s, 38.2 mPa∙s and 180.8 mPa∙s, respectively, and increased exponentially. It is shown that increasing the viscosity of the polyvinyl alcohol solution from 6 wt.% to 9 wt.% increases the thickness of the polyvinyl alcohol layer from (3.32 ± 0.97) µm to (8.09 ± 1.43) µm. No pronounced polyvinyl alcohol layer can be observed on samples dip-coated in 3 wt.% PVA solution. Increasing the viscosity of the polyvinyl alcohol solution from 3 wt.% to 9 wt.% increases the mechanical properties of the poly(lactide-co-glycolide) samples by a factor of 1.16–1.45. Cytotoxicity analysis of all samples reveals that none is toxic to 3T3-L1 fibroblast cells. A cell adhesion assay indicates that the anti-adhesion properties increase with increasing viscosity of the polyvinyl alcohol solution and the thickness of the polyvinyl alcohol layer on the poly(lactide-co-glycolide) scaffolds. Fluorescence images of the cells show that as the thickness of the polyvinyl alcohol coating increases, the number of cells decreases, and they do not cover the surface of the samples and form spherical three-dimensional agglomerates. The highest mechanical and anti-adhesion properties are obtained with the poly(lactide-co-glycolide) scaffold sample dip-coated in the 9 wt.% polyvinyl alcohol solution. This is because this sample has the thickest polyvinyl alcohol coating. Full article

Poly(D,L-lactide-co-glycolide) (PLGA) has emerged as a cornerstone in the development of advanced drug delivery systems, particularly for intranasal and pulmonary routes. Its biodegradability, biocompatibility, and adaptability make it an ideal platform for addressing challenges associated with conventional therapies. By enabling sustained and controlled drug release, PLGA formulations reduce dosing frequency, improve patient compliance, and enhance therapeutic efficacy. These systems demonstrate versatility, accommodating hydrophilic and hydrophobic drugs, biological molecules, and co-delivery of synergistic agents. Moreover, surface modifications and advanced preparation techniques enhance targeting, bioavailability, and stability, expanding PLGA’s applications to treat complex diseases such as tuberculosis, cancer, pulmonary fibrosis, and CNS disorders. This manuscript provides an in-depth review of PLGA’s materials, properties, preparation methods, and therapeutic applications, alongside a critical evaluation of challenges and future opportunities in this field. Full article