Degradação in vivo de membranas de poli(L-acido latico) contendo plastificante tri-etil-citrato

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

The increasing use of artificial materials for protheses has Iead to the development of products that meet the demands of impIantabIe materiaIs. The deveIopment of biodegradabIe materials has stimulated interest in the study of their interactions with host tissue in order to improve the likelihood of success in protheses. Biodegradable poly(L-lactic acid) membranes have been used for several purposes, including controlled release of drugs, as a barrier for soft and hard tissues and for replacing of damaged tissues. The physical properties of these materials can be modified by the addition of a plasticizer, such as the triethyIcitrate, to provide flexibiIity and porosity to the implants and to enhance the control of the polymer degradation time. The accurate addition of plasticizer thus allows the production of material for different applications so that the degradation time of the polymer can be made compatible with the proliferation of new tissue. The aim of this work was to examine the biological and morphoIogical properties of a porous membrane of PLLA containing 7% trietylcitrate until 180 days after implantation in the subcutaneous tissue of rats. Samples of skin obtained ITom female Wistar rats 2-180 days after implantation with PLLA-based membrane were processed for light microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and PCNA (proliferating Cell Nuclear Antigen) Immunocytochemistry. The results indicated that the membranes became surrounded by a delicate network of connective tissue which gradually invaded the membrane structure. Analysis by SEM indicated that the polymer degradation began with the appearance of radial tractures in the globular units of the biodegradable membrane, especially by 90 and 180 days after implantation. By immunocytochemistry, was possible to observe labeled nuc1eus, indicating cellular proliferation into the site of implantation

ASSUNTO(S)

membranas (biologia) biodegradação

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