Development of composites membranes for guided bone regeneration (GBR)

Abstract

The actual comercial membranes are divided in: non-resorbable, animal source resorbable and synthetic resorbable. Non-resorbable membranes exhibit biocompatibility and helps on bone regeneration in clinical trials [10]. However, those rigid membranes requires a second surgery for its remotion, often resulting on soft tissue deiscidence, exposing and infection vulnerability. In the case of animal source resorbable membranes, a disadvantage is the potencial of viral transmission, once, those membranes are produced from animal collagen, and after all they are xenogeneic proteins, differing from those found in human body. Because of that, some recent regulations for stem cell therapies (e.g. RDC9/2011) are signaling a substitution of animal sources materials for synthetic ones. By the way, the application challenge is to coincide the resorption time and the neo bone formation time. Beyond those disadvantages, all membranes categories acts only as a biological barriers, and don't stimulates a specific cellular response intended to accelerate or reinforce the bone regeneration. Calcium phosphates are well-known for they superior biocompatibility, osseoconductivity and biocompatibility, showing increase cell activity and the natural mineralization into bone defects [4]. The aim of this scientific proposal is to produce composite membranes (polymer/calcium phosphate) and assess their chemical-physical and mechanical properties. The combination of polymeric membranes and calcium phosphates bioactivity properties will promote an ideal concentration release of ionic dissolution elements as the membranes are resorbing, in the presence of cells on its surface. Polymer membranes will be produced based on Bellini's and coworkers method [5]; calcium phosphates ceramics will be synthesized by the chemical precipitation method [6-8]. The pH and temperature control during the synthesis is intended to promote tricalcium phosphate and hydroxyapatite phases, these are calcium phosphate phases that shows different in vitro and in vivo responses of dissolution and bioactivity, giving to the barrier the correct biological stability. The PIPE 1 research project is based in the comparison of produced composites membranes in terms of their mechanical and physical-chemical properties and the commercial available aiming to reach all the necessities reported by professionals of medical-dental area. Besides that, in vitro results are essential for predict the in vivo results showing a pathway for GBR success, assessing biocompatibility and the material capacity to induce a mesenchymal stem cell (MSC) differentiation. The project continuity, FASE 2, will analyze the cell-membrane association, that could lead to a role new concept of bone therapy, been an alternative for bone morphogenetic protein use. Immediately after biomaterial insertion, the MSC play a crucial role in bone formation due to its immunosuppressive characteristic and differentiation ability which will influence the bone repair process and the quality of new bone formed. (AU)