Alkaline treatments to render starch-based biodegradable polymers self-mineralizable

• Autor(a) principal: Leonor, I. B.
• Data de Publicação: 2007
• Outros Autores: Kim, H-M, Balas, F., Kawashita, M., Reis, R. L., Kokubo, T., Nakamura, T.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/20197
• topic: apatite; simulated body fluid (SBF); bioactivity; biodegradable polymer; functional groups; starch-based polymers; Science & Technology

The present research aims to develop a new route for surface functionalization of biodegradable polymers. The method is based on a wet chemistry modification, resulting in etching and/or hydrolysis in order to increase the amount of polar groups, such as hydroxyl (--OH) and carboxylic (--COOH) groups on the surface of the polymer. The polymer used as substrate was a corn starch-ethylene vinyl alcohol biodegradable blend (SEVA-C). For that purpose it was used in two different types of activation: (a) calcium hydroxide solution [Ca(OH)(2)] and (b) sodium hydroxide solution (NaOH). These treatments lead to the formation carboxylic acid-rich SEVA-C surfaces. Then, the samples were soaked in simulated body fluid (SBF) for different time periods of time until 7 days. After 1 day in SBF, the surface of SEVA-C was fully covered with spherulite particles. As the soaking time increased, the particles increased and coalesced, leading to the formation of a dense and uniform layer. Furthermore, thin-film X-ray diffraction confirms that the layer formed on the surface of the polymer was an apatite-like layer. These results suggest that this rather simple treatment is a good method for surface functionalization and subsequent mineral nucleation and growth on biodegradable polymeric surfaces to be used for bone-related applications.