Produção de biocompósito à base de polímero natural com partículas de biovidro como possível candidato para aplicações biomédicas

Abstract

The development of materials for biomedical applications has consistently presented challenges for researchers and medical professionals, as biomaterials must demonstrate biocompatibility and bioactivity when in contact with living tissue. In this context, various materials have been investigated as promising candidates, including polymers, glasses, and ceramics. Among these, bioactive bioglasses like 45S5-BG have gained particular attention due to their excellent bioactivity and biocompatibility. These bioglasses also form hydroxyapatite layers on their surfaces, playing a crucial role in tissue regeneration and treatment. However, due to their brittle nature, bioglasses exhibit limited mechanical properties, which has encouraged their incorporation into biocompatible polymers as a solution to enhance mechanical performance. This thesis investigates a biocomposite based on natural rubber (NR) reinforced with bioglass particles from the 45S5 system (BG). The influence of BG particles on the thermal, mechanical, and structural properties of the NR matrix was evaluated through thermogravimetric analyses (TGA), mechanical tests, and scanning electron microscopy (SEM). The results indicated that the addition of bioglass particles to the NR matrix positively impacted the mechanical and thermal properties of the biocomposite, suggesting its potential for biomedical applications. SEM analysis revealed a homogenous distribution of 45S5-BG particles within the NR matrix, with minimal agglomeration. Thermogravimetric (TG/DTG) tests on the biocomposites showed decomposition profiles similar to those of pure NR, with a well-defined main peak on the DTG curve in the 300–450°C temperature range, characteristic of the structural degradation of isoprene chains. TG analysis also revealed that the thermal stability of the samples increased with higher amounts of 45S5-BG in the biocomposite. Mechanical tests further demonstrated that adding 45S5-BG to the biocomposite improved the samples' mechanical properties; the NR matrix became more rigid with increased BG content, as evidenced by reduced deformation at rupture and increased tensile strength. Indirect cytotoxicity testing indicated that both pure NR and NR/45S5-BG biocomposites support mesenchymal stem cell (MSC) adhesion, with viability exceeding 70%, in compliance with ISO 10993-5:2009. These findings suggest that 45S5-BG particles enhance the tensile response and biological properties of the NR matrix, opening up a wide range of potential biomedical applications.