Fabricação por filamento fundido de compósitos à base de policaprolactona e fibras de vidro visando aplicações de engenharia de tecidos

Abstract

Among the fields of study in Tissue Engineering is the development of materials that present good mechanical performance, high bioactivity, and that can be processed using techniques that allow control flexibility regards architecture, such as fused filament fabrication (FFF). In this sense, the incorporation of bioactive glasses (BG) into polymer matrix is interesting, especially when they are in the form of continuous fibers (CF), filler with high reinforcing potential. Coating may be a method to prevent excessive polymer degradation during incorporating of BGs. Depending on the bioabsorption rate of the coating, it is possible to control the induction time of the bioactive effect of CFs. As a proof of concept, conventional glass CFs were coated with polycaprolactone (PCL) via extrusion. The resulting filaments, with up to 12.5% by mass of fillers, were processed via FFF. Flow modeling during FFF with CFs was developed, something not yet reported in the literature, and used to justify the quality of the printed materials. It was estimated that, with the CFs in the printing nozzle, the melt is subjected to 481 s^-1 of shear rate and 1.95 MPa/mm of pressure gradient, values three and two times greater compared to the case of neat PCL, respectively. The tensile strength of the formulation with CFs, 32 MPa, was twice as high compared to neat polymer. As part of the second front of this investigation, for the first time, PCL composites with short fibers or powder of F18 BG were produced via extrusion and FFF. This BG was chosen due to its high bioactivity and wide processing range, which allows it to be obtained in the form of fibers. F18 promoted mineralization and in vitro cellular activity. The research contributes to the development of scaffolds with interesting characteristics for biomedical applications.