Poly(l-lactic acid) short fibers prepared by solvent evaporation using sodium tripolyphosphate

Development of Polymer/Nanoceramic Composite Material with Potential Application in Biomedical Engineering

The rise of human life expectancy results in the increasing of elderly population and consequently the diseases of old age, which are mostly related with bone degenerative diseases. These problems also affect young individuals, commonly due to accidents (automobile and work). This fact has stimulated the research and development of materials that can replace or regenerate the damaged bone. From the engineering view, bone is a composite material consisting of an organic matrix (collagen), reinforced by an inorganic component (hydroxyapatite). The search for a suitable material, with properties tailored to the needs of the bone metabolism, as well as the adequate way of material processing, which ensures the maintenance or improvement of their initial properties, motivated this research. In this work was developed composite materials, based on bioresorbable polymer (PLLA) and phosphocalcic nanoceramic (HA). The composites were characterized by scanning electron microscopy (microstructure) and dynamical mechanical analyses (mechanical behavior). The results indicated these materials as promising for applications in the medical and dental manufacturing devices (plates and screws) by injection molding, and also for scaffolds by rapid manufacturing, in the tissue engineering area.

Preparation of Porous Composites with a Porous Framework Using Hydroxyapatite Whiskers and Poly(L-Lactic Acid) Short Fibers

A new type of porous composite with a porous framework was prepared using a mixture of hydroxyapatite whiskers (W-HA) and poly(L-lactic acid) short fibers (F-PLLA) by a particle-leaching technique. The material, composed of a porous framework with interconnecting pore of >1 µm, has large-sized pores of about 200 µm. The large-sized pores were formed by leaching sucrose granules. The porosity can be controlled in the range from 60 to 85 % by the sucrose content. The small-sized pores in the framework formed due to the poor densification of the W-HAs / F-PLLAs mixture. The pore distribution in the framework can be controlled by the compressing pressure without change in the distribution of large-sized pores.