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Desenvolvimento de um material osteoindutor a base de amido e polímero bioabsorvível

Tue, 18 Nov 2025 00:00:00 GMT

Título: Desenvolvimento de um material osteoindutor a base de amido e polímero bioabsorvível Abstract: In recent years, there has been significant progress in the field of tissue engineering and regenerative medicine, in which researchers from various disciplines seek alternatives for the development of biological substitutes aimed at replacing or regenerating diseased or damaged tissues. A promising strategy for bone tissue regeneration involves the use of scaffolds composed of bioabsorbable polymers combined with materials capable of stimulating bone regeneration. This study aims to develop a material with osteoinductive properties agent based on starch, Poly(Llactide-co-D,L-lactide) (PLDLA), and Poly(L-lactide-co-D,L-lactide-co-Trimethylene Carbonate) (PLDLA-co-TMC). To this purpose, four different formulations were prepared: I - PLDLA + 0.5% starch; II - PLDLA + 0.5% starch + PLDLA-TMC (5%); III - PLDLA + 0.5% starch + PLDLA-TMC (10%); and IV - PLDLA + 0.5% starch + PLDLATMC (15%). Dimethyl sulfoxide (DMSO) was used as the solvent, and membranes were obtained via solvent evaporation. To date, the samples have been characterized using Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Preliminary results indicate that the addition of PLDLA-TMC to the PLDLA/starch blend alters both the thermal and morphological properties of the system, as demonstrated by TGA, DSC, and SEM analyses. However, FTIR did not show any absorption indicative of indicating chemical interaction between the components. The analysis of mass loss during the degradation process is currently ongoing and has not yielded conclusive results so far. Additionally, the samples will be characterized regarding rheological behavior, zeta potential, mechanical bending tests, atomic force microscopy, and biological assays through the response of osteoblastic cells in the presence of the materials developed Tipo: Dissertação

Desenvolvimento de um hidrogel à base de celulose e quitosana contendo Óleo Essencial de Melaleuca no tratamento de onicomicose causada por dermatófito e levedura

Thu, 22 May 2025 00:00:00 GMT

Título: Desenvolvimento de um hidrogel à base de celulose e quitosana contendo Óleo Essencial de Melaleuca no tratamento de onicomicose causada por dermatófito e levedura Abstract: Onychomycosis is an infection caused by dermatophytic fungi and yeasts that affects 20% of the global population and accounts for 50% of all nail diseases. Currently, alternative therapies under investigation for the treatment of onychomycosis include the use of essential oils as potential antifungal agents. Objective: To develop a film[1]forming hydrogel combining hydroxypropyl methylcellulose (HPMC) and chitosan, associated with Tea Tree Essential Oil (TTO) at concentrations of 1%, 2%, and 5%, for the treatment of onychomycosis. Methodology: For material characterization, the following analyses were performed: Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TG), and Differential Scanning Calorimetry (DSC). For microbiological analyses, sensitivity testing was conducted by determining the inhibition zone and comparing it to standard antifungal agents (antifungigram), along with microbial growth inhibition analysis through optical density measurement, which assesses microbial growth in liquid medium by turbidity reading. Results: FTIR analysis showed no chemical interaction between the components, which is important to ensure the release of TTO for therapeutic purposes. DSC analysis indicated that increasing the TTO concentration reduced the interaction between TTO and the hydrogel components (HPMC and chitosan), facilitating the evaporation of TTO. TG analysis revealed that TTO concentration did not affect the thermal properties of the samples. In the microbiological analysis, the 2% and 5% TTO concentrations exhibited antifungal activity, which was more pronounced against yeasts. Conclusion: Considering these findings, compounded formulations based on cellulose and chitosan with Tea Tree Essential Oil for nail film formation are potential tools in the treatment of onychomycosis caused by dermatophytes or yeasts. In addition to being a natural, low[1]cost, and low-toxicity therapeutic alternative, future clinical trials are crucially important to confirm safety and efficacy Tipo: Dissertação

Avaliação da regeneração óssea craniana utilizando scaffolds baseados em Poli(L-co-D, L-ácido lático-co-trimetileno carbonato): estudo in vitro

Wed, 14 May 2025 00:00:00 GMT

Título: Avaliação da regeneração óssea craniana utilizando scaffolds baseados em Poli(L-co-D, L-ácido lático-co-trimetileno carbonato): estudo in vitro Abstract: Craniofacial bone regeneration represents a significant challenge in regenerative medicine due to the anatomical and functional complexity involved in repairing defects resulting from trauma, surgery, or congenital malformations. In this context, the development of bioabsorbable polymeric scaffolds has emerged as a promising strategy to promote effective and personalized bone regeneration. This study aimed to synthesize and evaluate in vitro three-dimensional scaffolds based on poly(L-co-D,L-lactic acid-co-trimethylene carbonate) (PLDLA-TMC), with potential application in cranial bone regeneration. The copolymer was synthesized and processed using sucrose as a porogenic agent in two pore size ranges (125~250 µm and 250~500 µm), followed by 3D extrusion printing at 150 °C in two thicknesses (0.8 and 1.2 mm). After printing, the scaffolds were immersed in distilled water to remove the sucrose and generate a porous structure. FTIR analysis confirmed successful copolymer synthesis, and rheological tests indicated pseudoplastic behavior. Thermogravimetric analysis (TGA) of the scaffolds revealed a shift in the onset temperature of mass loss after the printing and leaching processes. However, the DSC analysis did not show significant changes in the glass transition temperature (Tg) for the printed scaffolds. Zeta potential analysis demonstrated a pH-dependent negative surface charge. Scanning electron microscopy (SEM) revealed morphological differences related to thickness and pore size. Based on these analyses, scaffolds printed with thicknesses of 0.8 and 1.2 mm and pore sizes between 125~250 µm were selected for in vitro biological assays. The bioluminescence assay showed higher luciferase signal expression in the scaffolds with 1.2 mm thickness. Confocal laser scanning microscopy and SEM demonstrated good cell adhesion and proliferation on both materials, with osteopontin expression throughout the scaffold structure. Therefore, the set of results indicates that the printed PLDLA-TMC scaffolds exhibit favorable physicochemical and biological properties, making them promising candidates for craniofacial bone tissue engineering applications Tipo: Dissertação

Estudo da associação de micropartículas de poli-L-ácido láctico e policaprolactona na síntese de colágeno in vitro

Mon, 26 May 2025 00:00:00 GMT

Título: Estudo da associação de micropartículas de poli-L-ácido láctico e policaprolactona na síntese de colágeno in vitro Abstract: Skin photoaging, characterized by the replacement of the collagen matrix with dysfunctional fibers, drives the growing demand for biomaterials capable of stimulating collagen production in aesthetics and tissue engineering. Poly-L-lactic acid (PLLA) and polycaprolactone (PCL) are widely used biomaterials aimed at promoting neocollagenesis. This study evaluated the effect of the combined use of PLLA and PCL microparticles on type I collagen synthesis in vitro, using murine fibroblast and macrophage cultures. Microparticles with an average diameter of 2􀀀μm were obtained and characterized by Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and particle size distribution analysis. Cell viability was assessed using the MTT assay on days 1, 3, and 7. Type I collagen production was quantified by ELISA over a 14-day period. The results demonstrated that the microparticles retained their chemical and mechanical properties, and the combination of PLLA and PCL did not impair cell viability. Moreover, it resulted in significantly higher collagen production (p􀀀<􀀀0.01) compared to isolated microparticles. The association of both polymers created a more favorable microenvironment for collagen fiber production by fibroblasts, possibly due to improved particle internalization. It is concluded that the combination of PLLA and PCL microparticles represents a simple and more effective therapeutic strategy for stimulating neocollagenesis, showing promising potential as a dermal biostimulant in orofacial harmonization and/or the treatment of dermal soft tissue defects Tipo: Dissertação