The experimental use of poly (alcohol-vinyl) (PVA) as a skin curative is increasing widely. However, the use of this hydrogel is challenging due to its favorable properties for microbiota growth. The association with silver nanoparticles (AgNPs) as an antimicrobial agent turns the match for PVA as a dressing, as it focuses on creating a physical barrier to avoid wound dehydration. When associated with extracellular components, such as the collagen matrix, the device obtained can create the desired biological conditions to act as a skin substitute. This study aimed to analyze the anti-microbiological activity and the in vitro and in vivo responses of a bilaminar device of PVA containing AgNPs associated with a membrane of collagen–hyaluronic acid (col-HA). Additionally, mesenchymal stem cells were cultured in the device to evaluate in vitro responses and in vivo immunomodulatory and healing behavior. The device morphology revealed a porous pattern that favored water retention and in vitro cell adhesion. Controlled wounds in the dorsal back of rat skins revealed a striking skin remodeling with new epidermis fulfilling all previously injured areas after 14 and 28 days. No infections or significant inflammations were observed, despite increased angiogenesis, and no fibrosis-markers were identified as compared to controls. Although few antibacterial activities were obtained, the addition of AgNPs prevented fungal growth. All results demonstrated that the combination of the components used here as a dermal device, chosen according to previous miscellany studies of low/mid-cost biomaterials, can promote skin protection avoiding infections and dehydration, minimize the typical wound inflammatory responses, and favor the cellular healing responses, features that give rise to further clinical trials of the device here developed

A recent and quite promising technique for bone tissue engineering is the 3D printing, peculiarly regarding the production of high-quality scaffolds. The 3D printed scaffold strictly provides suitable characteristics for living cells, in order to induce treatment, reconstruction and substitution of injured tissue. The purpose of this work was to evaluate the behavior of the 3D scaffold based on Poly(L-co-D,L lactic acid-co-Trimethylene Carbonate) (PLDLA-TMC), which was designed in Solidworks™ software, projected in 3D Slicer™, 3D printed in filament extrusion, cultured with mesenchymal stem cells (MSCs) and tested in vitro and in vivo models. For in vitro study, the MSCs were seeded in a PLDLA-TMC 3D scaffold with 600 μm pore size and submitted to proliferation and osteogenic differentiation. The in vivo assays implanted the PLDLA-TMC scaffolds with or without MSCs in the calvaria of Wistar rats submitted to 8 mm cranial bone defect, in periods of 8–12 weeks. The results showed that PLDLA-TMC 3D scaffolds favored adherence and cell growth, and suggests an osteoinductive activity, which means that the material itself augmented cellular differentiation. The implanted PLDLA-TMC containing MSCs, showed better results after 12 weeks prior grafting, due the absence of inflammatory processes, enlarged regeneration of bone tissue and facilitated angiogenesis. Notwithstanding, the 3D PLDLA-TMC itself implanted enriched tissue repair; the addition of cells known to upregulate tissue healing reinforce the perspectives for the PLDLA-TMC applications in the field of bone tissue engineering in clinical trials.

Three-dimensional (3D) structures are actually the state-of-the-art technique to create porous scaffolds for tissue engineering. Since regeneration in cartilage tissue is limited due to intrinsic cellular properties this study aims to develop and characterize three-dimensional porous scaffolds of poly (L-co-D, L lactide-co-trimethylene carbonate), PLDLA-TMC, obtained by 3D fiber deposition technique. The PLDLA-TMC terpolymer scaffolds (70:30), were obtained and characterized by scanning electron microscopy, gel permeation chromatography, differential scanning calorimetry, thermal gravimetric analysis, compression mechanical testing and study on in vitro degradation, which showed its amorphous characteristics, cylindrical geometry, and interconnected pores. The in vitro degradation study showed significant loss of mechanical properties compatible with a decrease in molar mass, accompanied by changes in morphology. The histocompatibility association of mesenchymal stem cells from rabbit’s bone marrow, and PLDLA-TMC scaffolds, were evaluated in the meniscus regeneration, proving the potential of cell culture at in vivo tissue regeneration. Nine New Zealand rabbits underwent total medial meniscectomy, yielding three treatments: implantation of the seeded PLDLA-TMC scaffold, implantation of the unseeded PLDLA-TMC and negative control (defect without any implant). After 24 weeks, the results revealed the presence of fibrocartilage in the animals treated with polymer. However, the regeneration obtained with the seeded PLDLA-TMC scaffolds with mesenchymal stem cells had become intimal to mature fibrocartilaginous tissue of normal meniscus both macroscopically and histologically. This study demonstrated the effectiveness of the PLDLA-TMC scaffold in meniscus regeneration and the potential of mesenchymal stem cells in tissue engineering, without the use of growth factors. It is concluded that bioresorbable polymers represent a promising alternative for tissue regeneration.

Background/Objectives: Cachexia is a syndrome characterized by the progressive loss of muscle mass, leading to high morbidity and mortality. Ghrelin (Ghrl) exhibits orexigenic, anabolic, and anti-inflammatory properties with therapeutic potential. However, its low bioavailability limits the efficacy of systemic treatments. This study aimed to develop chitosan-coated liposomes containing Ghrl (CH-Lip + Ghrl) for intranasal administration, allowing quantification of Ghrl brain bioavailability using a system optimized for a labile neuropeptide. Methods: The formulation was prepared using thin-film hydration, followed by extrusion and chitosan coating. It was characterized based on morphology, size, zeta potential, stability, encapsulation efficiency, and cell viability. Permeation and mucoadhesion were evaluated ex vivo using porcine nasal mucosa, and cerebral bioavailability was assessed in Wistar rats. Results: CH-Lip + Ghrl had an average of 152.4 ± 0.2 nm (evaluated by DLS), a polydispersity index of 0.159 ± 0.018, a zeta potential of +60.8 ± 6.6 mV, and an encapsulation efficiency of 53.2 ± 0.8%, maintaining stability for 180 days. At 1% (v/v) in culture medium, the formulation retained 73.2 ± 8.4% of the viability in nasal epithelial cells and 81.9 ± 4.8% in neuroblastoma cells. Chitosan coating increased ex vivo mucoadhesion 1.7-fold and permeation 1.3-fold. In vivo, 25 min after intranasal administration, CH-Lip + Ghrl delivered 48.2 ± 8.8% of the dose to the brain, whereas free Ghrl was undetectable. Conclusions: The intranasal administration of CH-Lip + Ghrl enhances cerebral bioavailability of Ghrl. This study integrates a chemically labile neuropeptide with chitosan-coated liposomes for direct brain delivery, representing an innovative platform for future translational studies.

Research on dermal dressings has become increasingly important due to the need for affordable, effective, and accessible alternatives to costly and invasive conventional treatments, with materials such as Latex from Hevea brasiliensis and Polyvinyl alcohol (PVA) standing out for their biocompatibility, elasticity, ease of processing, angiogenic potential, and low production cost. This study compared four latex/PVA membrane ratios: 50%/50%, 75%/25%, 80%/20%, and 90%/10%. Several techniques, including Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), swelling and tensile tests, Scanning Electron Microscopy (SEM), zeta potential measurements, and in vitro biological assays, were employed. Results showed that membranes with 75%/25% and 80%/20% ratios exhibited superior physicochemical properties. The presence of PVA increased the swelling rate of the membranes, while the zeta potential analysis indicated that latex enhances the negative surface charges. Mechanically, the latex/PVA blend significantly influenced the samples' behavior: the 50%/50% and 75%/25% compositions reduced the latex elastomeric capacity, whereas the 80%/20% and 90%/10% compositions exhibited a more amorphous behavior, similar to that of pure latex. SEM analysis revealed homogeneity, porosity, and surface roughness in these compositions. In vitro biological assays indicated enhanced cell adhesion and proliferation, suggesting a promising synergy of these polymers for dermal dressings.