Haste intramedular polimérica bioreabsorvível (PLLA/PHBV) para uso na recuperação de fraturas ósseas

Abstract

Resumo: A crescente utilização de materiais poliméricos bioreabsorvíveis em medicina, tem estimulado pesquisadores na área ortopédica na busca de soluções mais biológicas, substituindo artefatos tais como fios, hastes e placas metálicas por polímeros bioreabsorvíveis no tratamento de fraturas. Para tanto, resolveu-se estudar implantes da blenda de PLLA/PHBV (dois polímeros bioreabsorvíveis) moldados em uma mini-injetora. Esses implantes foram utilizados para recuperação de fraturas de fêmur de coelhos e avaliados em comparação ao fio de Steinmann (aço inox, usado comercialmente). Após eutanásia com 6, 12 e 24 semanas de implantação dos artefatos, os ossos foram estudados com radiografias, exame histológico e ensaio mecânico, enquanto os implantes poliméricos foram submetidos a microscopia eletrônica de varredura (SEM), ensaio mecânico e calorimetria diferencial de varredura modular (MDSC). As radiografias mostraram calos ósseos bem formados, tanto com o uso da haste de polímero como com o controle metálico. O estudo histológico mostrou ausência de reações inflamatórias ou osteólise. O ensaio mecânico mostrou que a consolidação óssea ocorreu nos dois grupos. Tanto no ensaio mecânico como na calorimetria observou-se que a haste polimérica apresentou sinais de degradação progressiva no tempo estudado. Com os dados obtidos neste estudo, podemos afirmar que o implante PLLA/PHBV demonstrou ser efetivo na reparação de fraturas do fêmur de coelhos quando comparado com o controle metálico. Palavras-chave: PLLA, PHBV, polímeros bioreabsorvíveis, degradação in vivo, osteossíntese de fraturas. Intramedullary Bioresorbable Polymeric Pin (PLLA/PHBV) for Use in Bone Fracture RecuperationAbstract: The growing interest in medicine with the use of bioreabsorbable polymeric materials has been stimulating researchers from orthopedic area to develop more biological solutions, substituting threads, stems and metallic plates for bioreabsorbable polymers in the treatment of fractures. So, we decided to study implants of the PLLA/PHBV blends (two bioreabsorbable polymers) moulded in a mini-injector. Those implants were used for recovery of fractures of rabbit femur and assessed in comparison with the thread of Steinmann (stainless steel, commercially used). After euthanasia with 6, 12 and 24 weeks of implantation of the artifacts, the bones were studied with X ray, histological exam and mechanic test, while the polymeric implants were submitted the scanning electron microscopy (SEM), mechanic test and modular differential scanning calorimetry (MDSC). The X ray showed good calluses bone with the use of the polymer stem as well as with the metallic control. The histological study showed absence of inflammatory reactions or osteolysis. The mechanical test showed bone consolidation in the two groups. In the mechanical test and in the calorimetry studies, the polymeric stem presented signs of progressive degradation within the studied time. With the data obtained, we can state that the implant PLLA/PHBV demonstrated to be as effective in rep...

Development, Characterization, and Cellular Adhesion of Poly(l‐Lactic Acid)/Poly(Caprolactone Triol) Membranes for Potential Application in Bone Tissue Regeneration

“…Figure 2a shows two stages, one characteristic of PLLA and another of PCL-T, for the 90/10 and 70/30 preparations, with two Tg values: 50.21°C for PLLA and −76.79°C for PCL-T in the 90/10 preparation, 64.11°C for PLLA and −73.89°C for PCL-T in the 70/30 system. Published work establishes that in partially miscible PLLA/poly (3-hydroxybutyrate-co-3-hydroxyvalerate) systems, there are two distinct Tg values, different from the Tg values of the pure components (16).…”

Behavior study of the doped castor bean polymer rod with bioactive glass and hidroxyapatite in mice femur medullary canal

“…The technological advance has allowed the development of a great variety of material instruments for implant and techniques for the internal fixation of fractures in humans. In this way, the search for lighter, more resistant, low cost and biocompatible materials has grown 2 for more biological solutions and replacing artifacts such as wire rods and metal plates by bioreabsorbable polymers in the fractures treatment 3 . Among these polymers, polyurethane derived from castor oil has been outstanding because it is a low cost material developed in Brazil that has excellent structural properties, which has been shown to be biocompatible 4 , and for combining the versatility of the polymer formulation while addressing the global concern in the production of new biomaterial resources becoming one of the most studied 5 .…”