Electrospun silk-elastin-like fiber mats for tissue engineering applications

Protein-based polymers are present in a wide variety of organisms fulfilling structural and mechanical roles. Advances in protein engineering and recombinant DNA technology allow the design and production of recombinant protein-based polymers (rPBPs) with an absolute control of its composition. Although the application of recombinant proteins as biomaterials is still an emerging technology, the possibilities are limitless and far superior to natural or synthetic materials, as the complexity of the structural design can be fully customized. In this work, we report the electrospinning of two new genetically engineered silk-elastin-like proteins (SELPs) consisting of alternate silk- and elastin-like blocks. Electrospinning was performed with formic acid and aqueous solutions at different concentrations without addition of further agents. The size and morphology of the electrospun structures was characterized by scanning electron microscopy showing to be dependent of concentration and solvent used. Treatment with air saturated with methanol was employed to stabilize the structure and promote water insolubility through a time-dependent conversion of random coils into β-sheets (FTIR). The resultant methanol-treated electrospun mats were characterized for swelling degree (570-720%), water vapour transmission rate (1083 g/m2/day) and mechanical properties (modulus of elasticity of ~126 MPa). Furthermore, the methanol-treated SELP fiber mats showed no cytotoxicity and were able to support adhesion and proliferation of normal human skin fibroblasts. Adhesion was characterized by a filopodia-mediated mechanism. These results demonstrate that SELP fiber mats can provide promising solutions for the development of novel biomaterials suitable for tissue engineering applications.

Anotação, numa perspectiva de Direito Penal e de Criminologia, de alguns dos aspectos do Acórdão do Supremo Tribunal de Justiça (português), de 28 de Setembro de 2011 - os problemas do direito ao silêncio e do dever em o arguido se sujeitar a aplicações de prova no processo penal

Resumo: 1 – Sumário do Acórdão do Supremo Tribunal de Justiça, de 28 de Setembro de 2011; 2 – Texto completo do Acórdão do Supremo Tribunal de Justiça, de 28 de Setembro de 2011, Juiz Conselheiro Raul BORGES (Relator), Juiz Conselheiro Armindo MONTEIRO cfr. http://www.dgsi.pt , 20 de Janeiro de 2012; 3 – Anotação; 3.1 – Introdução à anotação; 3.2 – Algumas das referências, por parte do Acórdão do Supremo Tribunal de Justiça, de 28 de Setembro de 2011, aos problemas do direito ao silêncio e do dever em o arguido se sujeitar a aplicações de prova no processo penal; 3.3 – «Teoria geral» dos problemas do direito ao silêncio em contraste com o dever de sujeição do arguido a diligências de prova no contexto do direito processual penal lusitano; 4 - Conclusão. § Abstract: 1 - Summary of the Judgement of the Supreme Court of Justice of 28 September 2011 2 - Full text of the Judgement of the Supreme Court of Justice of 28 September 2011, Councillor Judge Raul Borges (Reporter), Councillor Judge Armindo Monteiro cf. . http://www.dgsi.pt, January 20, 2012, 3 - Note: 3.1 - Introduction to the annotation; 3.2 - Some of the references, by the Judgement of the Supreme Court of Justice of 28 September 2011, the problems the right to silence and the duty in the defendant be subject to applications of proof in criminal proceedings; 3.3 - "general Theory" of the problems the right to silence in contrast to the duty of subjection of the accused to proof steps in the right context criminal procedure Lusitanian 4 - Conclusion. P.S.: este é o "abstract" tal qual como surge no artigo.