Liberação de componentes do extrato de Casearia sylvestris Swartz empregando membranas de látex natural como suporte

• Autor(a) principal: Trecco, Alberto [UNESP]
• Data de Publicação: 2014
• Outros Autores: Borges, Felipe Azevedo [UNESP], Pierri, Elaise G. [UNESP], dos Santos, André Gonzaga [UNESP], Chin, Chung Man [UNESP], Herculano, Rondinelli Donizetti [UNESP]
• Tipo de documento: Artigo
• Idioma: eng; por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://serv-bib.fcfar.unesp.br/seer/index.php/Cien_Farm/article/view/2791; http://hdl.handle.net/11449/180910
• topic: Casearia sylvestris; Látex natural; Liberação controlada; pH; Hevea brasiliensis; Casearia sylvestris; Natural rubber; Controlled release; pH sensitive; Hevea brasiliensis

Natural Rubber Latex (NRL) membrane, made from latex extracted from the rubber tree Hevea brasiliensis, has shown great potential for use in the biomedicine and biomaterials area. Thanks to its biocompatibility and low rejection rate, it has been used for implants and grafts, acting as a stimulant of angiogenesis and cell adhesion and as a barrier against infectious agents. Besides these applications, the membranes are used as model release systems, to assess the release behavior of drugs and plant extracts that exhibit medicinal properties. The extract-membrane system represents a new approach to studying these substances, as aids to wound healing and tissue regeneration. Casearia sylvestris, popularly known as guaçatonga, belongs to the family Salicaceae, known in popular medicine for its anti-ulcerogenic, wound healing, anti-ophidian, antiinflammatory and antiseptic properties, all of which are proven by scientific studies. Recent studies have also shown that the controlled release of drugs and extracts from natural latex membranes is an interesting and promising process for biomedical applications. The objective of this project was thus to study the release of Casearia sylvestris extract incorporated into natural rubber membranes. The main concern was to study and optimize the controlled release of the extract at various pHs. The rate of release was monitored and analyzed by the method of optical spectroscopy (UV). Basic pH acts to destabilize the membrane, indicating that the polymer has the ability to protect the extract from being released at acidic pH values. The controlled release follows a bi-exponential function y(t) = y0 +A1e–t/τ1 + A2e-t/τ2, where the release profile of the extract from the NRL membrane shows a first, fast step of burst release of the extract absorbed near or on the surface of the NRL membrane, then a slower release of extract in the bulk NRL. We observed the strongest influence of pH on the membranes submerged in the pH=7.6 solution. Moreover, results indicate that, with very simple changes in NRL preparation, it is possible to control the extract release up to 10 days and design membranes for the treatment of specific tissues and organs.