Publicação
Patterned surfaces of poly (lactic acid) and starch – poly (lactic acid) blend prepared by reverse breath figures, the effect of : solvent, substrate and vapour
| Resumo: | Thin polymeric films and patterns hold great promise for several applications. Many micro or nanofabrication techniques allow designing regular and ordered materials. With these techniques, good architecture reproducibility as well as porosity control of the structure can be obtained, using a vast range of polymers, including biodegradable (natural or synthetic) polymers. This work dealt with the fabrication of patterned surfaces with regular geometry by using templating techniques, breath figures (BF) and reverse breath figures (RBF) in an in-house built microfabrication system. For this purpose we have prepared biodegradable polymeric patterns of poly (lactic acid) (PLA) and a starch – poly (lactic acid) blend (SPLA) with different morphologies in this in-house built system. The PLA and SPLA dissolved in chloroform and toluene (TL) (1%wt) were exposed to a vapour atmosphere with mixtures of water (H2O) and methanol (MeOH). Three types of patterned surfaces were obtained, particles, porous films or an intermediate pattern, where both particles and film coexist. The structures developed, by this novel approach to create biodegradable materials using a natural based polymer, could have potential applications in tissue engineering or cell growth, by themselves or as a coating for other materials. These applications consist in the use a combination of living cells and a support structure in which cell attach, grow and proliferate. Due to this kind of potential applications of the materials created, they should meet specific characteristics; in particular the used material should be non-toxic and possess high cell/tissue biocompatibility so that they will not give rise to any unfavorable behavior. Moreover, it should have a determinate surface to permit cell adhesion. Scan electron microscopy (SEM) imaging was used to observe the morphology of the structures created Thermal analysis differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) were carried out to characterize the PLA. Also the cell adhesion and growth on the surfaces created was tested. This was performed with the aid of MTS assay, fluorescence microscope and SEM. After MTS evaluation proved the non-cytotoxicity of the materials, preliminary biological tests were done by seeding on the surfaces osteoblasts cell lines. SEM imaging and fluorescence microscopy evidenced morphology and cell adhesion and growth behavior over the patterns. |
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| Autores principais: | Sousa, Nuno André Carvalho |
| Ano: | 2011 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Thin polymeric films and patterns hold great promise for several applications. Many micro or nanofabrication techniques allow designing regular and ordered materials. With these techniques, good architecture reproducibility as well as porosity control of the structure can be obtained, using a vast range of polymers, including biodegradable (natural or synthetic) polymers. This work dealt with the fabrication of patterned surfaces with regular geometry by using templating techniques, breath figures (BF) and reverse breath figures (RBF) in an in-house built microfabrication system. For this purpose we have prepared biodegradable polymeric patterns of poly (lactic acid) (PLA) and a starch – poly (lactic acid) blend (SPLA) with different morphologies in this in-house built system. The PLA and SPLA dissolved in chloroform and toluene (TL) (1%wt) were exposed to a vapour atmosphere with mixtures of water (H2O) and methanol (MeOH). Three types of patterned surfaces were obtained, particles, porous films or an intermediate pattern, where both particles and film coexist. The structures developed, by this novel approach to create biodegradable materials using a natural based polymer, could have potential applications in tissue engineering or cell growth, by themselves or as a coating for other materials. These applications consist in the use a combination of living cells and a support structure in which cell attach, grow and proliferate. Due to this kind of potential applications of the materials created, they should meet specific characteristics; in particular the used material should be non-toxic and possess high cell/tissue biocompatibility so that they will not give rise to any unfavorable behavior. Moreover, it should have a determinate surface to permit cell adhesion. Scan electron microscopy (SEM) imaging was used to observe the morphology of the structures created Thermal analysis differential scanning calorimetry (DSC) and gel permeation chromatography (GPC) were carried out to characterize the PLA. Also the cell adhesion and growth on the surfaces created was tested. This was performed with the aid of MTS assay, fluorescence microscope and SEM. After MTS evaluation proved the non-cytotoxicity of the materials, preliminary biological tests were done by seeding on the surfaces osteoblasts cell lines. SEM imaging and fluorescence microscopy evidenced morphology and cell adhesion and growth behavior over the patterns. |
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