Immunohistochemical Identification of macrophages in a poly (L-lactic acid) film implant with standard and superhydrophobic wettability

• Autor(a) principal: Garcia, Samuel Sales
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10348/10177
• topic: tissue engineering; poly (L-lactic acid)

In the Tissue Engineering area, it is common the use biomaterials composed by matrices with a high percentage of collagen, which are perfect to tissue rebuilding and Regenerative Medicine. It is also known that the collagen support cell migration and vascularization process. However, in recent decades, the use of polymers as scaffolding matrices in tissue regeneration has been widely extended. Polymers can be modified to gather the desired biodegradability and bioactivity characteristics, and they have a wide variety of mechanical characteristics, which gives them different functions in accordance with the material component. The functions that are most indorsed to these biomaterials are drug delivery and temporary prosthesis. Thus, in this work, poly (L-lactic acid) (PLLA) films with different wettability (standard / super-hydrophobic) (S and SH, respectively) were used in an in vivo subcutaneous implant in rats (Rattus norvegicus) in order to measure the inflammatory response, using immunohistochemistry technique. The semi-crystalline polymer poly (L-lactic acid) is an aliphatic polyester which is characterized by good biodegradability, biocompatibility and versatility, and it has reasonable mechanical and processability properties in fiber formation. After implantation, it occurs an immune response in the surgery local, and depending on the implanted materials characteristics, the inflammatory reaction will vary. For this study 18 rats were used, 9 were implanted with PLLA S and 9 with PLLA SH. Each rat was implanted with 6 PLLA discs in 6 different sites, 4 subcutaneously and 2 intramuscularly. After collecting the samples (n=108), immunohistochemistry was performed for three antibodies: CD3 (T lymphocytes), CD163 (M2 macrophages) and CD68 (Total macrophages). There was a decrease in the number of cells identified around the site of the implant site for both biomaterials, where it was possible to verify that the superhydrophobic PLLA promoted a minor inflammatory response. Therefore, it was observed that for both biomaterials the inflammatory reaction decreased over time and that the adaptive immune system was not strongly activated.