Poly(l-lactide)/poly(caprolactone triol) (PLLA/ PCL-T) membranes were prepared by solution casting in 100/0, 90/10, and 70/30 (w/w) ratios. The membranes were analyzed by dynamic mechanical analysis, differential scanning calorimetry, and mechanical tests.The thermal analysis showed that the 90/10 and 70/30 preparations were partly miscible systems. The glass transition temperature (Tg) of PLLA decreases as the PCL-T concentration increases, which implies that PCL-T has a plasticizer function. An in vitro study with osteoblastic cells isolated from the calvariae of rats was performed in all preparations. The results obtained in this study showed that the addition of PCL-T to the PLLA matrix modifies its mechanical, thermal, and biological properties. These blends could be useful for tissue engineering for bone applications.

The search for new therapies and drugs that act as topical agents to relieve pain and control the infectious processes in burns always attracted interest in clinical trials. As an alternative to synthetic drugs, the use of natural extracts is useful in the development of new strategies and formulations for improving the life quality. The aim of this study was to develop a wound dressing using Poly(L-co-D,L lactic acid-co-TMC) (PLDLA-co-TMC) containing aloe vera (AV). This natural plant extract is known for its modulatory effects under healing process. The membrane of PLDLA-co-TMC+aloe vera was prepared at different concentrations of AV (5, 10, 15 and 50%). The FTIR showed no change in the PLDLA-co-TMC spectrum after AV addition, while the swelling test showed changes only in PLDLA-co-TMC+AV at 50%. The wettability measurements showed decrease in the contact angle in all samples after the AV addition in the polymer, while the AV release test showed that PLDLA-co-TMC+50%AV sample has higher AV release rate than the sample with other AV concentrations. The SEM analysis showed that AV was homogeneously distributed at 5% only. Tensile tests demonstrated an increase in the Young's modulus and a reduction in the elongation till rupture of the PLDLA-co-TMC after the addition of AV. Biocompatibility in vitro evaluation with fibroblast cells seeded in the membranes of PLDLA-co-TMC+AV showed that the cells were able to adhere, proliferate and maintain mitochondrial activity in all AV concentrations tested. Due to the known skin medicinal properties attributed to AV and the results here obtained, we suggest that after in vivo trials, the PLDLA-co-TMC+AV should be a promising biomaterial for application as a device for skin curative and healing agent.

ObjectiveThis experimental study aimed to evaluate the biological performance of poly (l-co-D, l-lactic acid)-co-trimetilene carbonate/poly (vinyl alcohol) (PLDLA-co TMC/PVA), hydrogel scaffolds, as an implant in the filling (and not in the repair) of osteochondral defects in New Zealand rabbits, assessing the influence of the material in tissue protection in vivo.MethodsTwelve rabbits were divided into groups of nine and 16 weeks. In each animal, an osteochondral defect was created in both medial femoral condyles. In one knee, a hydrogel scaffold was implanted (pin group) and in the other, the defect was maintained (control group). A histological analysis of the material was performed after euthanasia.ResultsThe condyles of the pin group showed no inflammatory reaction and were surrounded by a fibrous capsule. The control group presented higher bone growth in the areas of the defect, but with disorganized articular cartilage, evident fibrosis, bone exposure, atrophy, and proliferation of synovial membrane.ConclusionThe hydrogel pins are promising in filling osteochondral defects, generally do not cause inflammatory reactions, and are not effective in the repair of osteochondral defects.

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Objetivo: O estudo buscou analisar a aplicação do hidrogel de Poli (NIPAAm-co-AAc-co-HEMAPLDLA-co-TMC) in vivo, acompanhando as reações teciduais desencadeadas ao redor. Métodos: Os implantes desse polímero foram realizados por via injetável no tecido subcutâneo do dorso posterior de 21 ratos Wistar. Após o período de cinco, sete, dez, 15, 21 e 30 dias ocorreu o sacrifício dos animais e posterior análise histológica. Resultados: Ausência de inflamação no local do implante e presença de espaçamentos deixados em decorrência do implante (que foi removido em razão do processamento). A ausência de resposta inflamatória significativa inviabilizou a realização de uma análise estatística dela. Conclusão: O hidrogel Poli (NIPAAm-co-AAc-co-HEMAPLDLA-co-TMC) apresenta biocompatibilidade e potencial como material de preenchimento, sendo necessários maiores estudos para que se possa entender a sua termossensibilidade e localizá-lo sem a presença de corante.