Estudo da Biocompatibilidade da Blenda de Poli(L-ácido láctico)/Policaprolactona-triol

Abstract

Resumo: Polímeros biorreabsorvíveis têm sido estudados para aplicações médicas especialmente nas áreas de ortopedia e traumatologia. Dentre os mais promissores destaca-se o poli(L-ácido láctico), devido a sua elevada resistência e boa biocompatibilidade. Apesar dessas características os dispositivos obtidos a partir do PLLA têm baixa elongação e um caráter hidrofóbico, fatores que dificultam seu emprego em aplicações onde a interação tecido/implante seja um fator importante. O objetivo do trabalho foi obter membranas de PLLA e melhorar suas propriedades pela adição de 10% de poli(ε-caprolactone) (PCL-triol), um polímero semicristalino. Para isso membranas foram implantadas no tecido subcutâneo de ratos Wistar, e análises histológicas dos segmentos das áreas implantadas foram realizadas nos tempos de 2, 7, 15, 30, 60, 90, 180 dias a fim de se avaliarem as interações polímero/tecido. Não foram observadas respostas inflamatórias exacerbadas em nenhum tempo estudado. Verificou-se a formação de cápsula fibrosa envolvendo a área implantada com presença de fibroblastos, fibrócitos e células gigantes multinucleadas. Concluímos que as membranas de PLLA contendo PCL-triol apresentaram resistência ao processo de degradação, podendo ainda ser observadas após 180 dias de estudo. Palavras-chave: PLLA/PCL-triol, in vivo, biocompatibilidade. Biocompatibility Study of Poly(L-acid-lactic)/Polycaprolactone Triol BlendAbstract: Bioabsorbable polymers have been studied for medical applications, especially for orthopedics and traumatology area. Among these promising polymers there is great emphasis on Poly (l-lactic acid), PLLA, due to its high strength and good biocompatibility. In spite of these characteristics, the devices obtained from the PLLA have low elongation and a hydrophobic character, which hamper its use in applications in which the tissue/implant interaction is an important factor. The aim of this work is to obtain PLLA membranes and to improve its properties adding 10% of poly (ε-caprolactone) (PCL-triol), a semicrystalline polymer. For this proposal membranes were implanted in the subcutaneous tissue of Wistar rats and histological analyses of the segments from the implanted areas were performed after 2,7,15, 30, 60, 90, 180 days in order to analyze the polymer / tissue interactions. No intense inflammatory reaction was observed along the period of time of the experiment. Fibrous capsules were noted enclosing the area of the implant, in addition to the presence of fibroblasts, fibrocytes and multinucleated giant cells. The PLLA membranes containing PCL-triol showed resistance to the degradation process, even after 180 days. Keywords: PLLA/PCL-triol, in vivo, biocompatibility. IntroduçãoDispositivos obtidos a partir de polímeros biorreabsorvíveis têm sido cada vez mais aceitos na área médica, seja como dispositivos na forma de mini placas e parafusos para fixação de fraturas, em substituição aos tradicionais implantes metálicos, até dispositivos empregados na liberação controlada de fármacos [1,2] . Esses materiais ap...

Biocompatibility Assessment of Polycaprolactone/Polylactic Acid/Zinc Oxide Nanoparticle Composites under In Vivo Conditions for Biomedical Applications

“…When comparing histological images of the F2 and F1 formulations, the only apparent difference appears to be the presence of the capsule (Figure 8A,B) and a slight increase in the number of inflammatory cells (Figures 7C and 8C). This finding of the presence of a capsule surrounding the implanted material is similar to that reported by other authors who, for the same 60-day period, describe the existence of a capsule around PLA and PCL composites [68,69].…”

Biocompatibility Assessment of Polylactic Acid (PLA) and Nanobioglass (n-BG) Nanocomposites for Biomedical Applications

“…The high persistence of nanocomposites in the subdermal tissue was due to the high crystallinity of the PLA, which was difficult for cell adhesion and penetration for the phagocytic process, causing slow degradation and reabsorption. It has been reported that some implants made of this material stimulate chronic inflammation and foreign body reactions with the presence of inflammatory infiltrate, fibrous capsules, and capillaries [ 62 , 63 ], as evidenced here. However, with the n-BGs incorporation, the reabsorption capacity increased.…”

Gamma irradiation effects on polycaprolactone/zinc oxide nanocomposite films

“…However, PCL has low thermo-mechanical properties and high gas permeability [1] . The strategy adopted to control this is to add inorganic nanomaterials to the polymer [12] , obtaining a nanocomposite and add also other polymers [13,14] . Among the nanomaterials that can be mixed with PCL, the nanoparticles of ZnO can be used [15] .…”