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Abstract:The term calcium phosphate cement was introduced by Gruninger et al. (1). This type of cement can be prepared by reacting a calcium phosphate salt with an aqueous solution, which causes it to set by the crossing of the precipitated crystals. These cements offer a series of advantages that allow their use as grafts and substitutes of damaged parts of the bone system. However, these cements have low mechanical strength compared to human bones. This work studied the influence of the use of polyamide fibers in the mechanical properties of a calcium phosphate cement based on ␣-tricalcium phosphate as well as the mechanisms involved in the increase of mechanical strength. The results demonstrate the feasibility of the use of polymeric fibers to increase mechanical strength and the need for coupling agents for the effective performance of the fibers as reinforcement in these materials.

Chitosan, which is a non-toxic, biodegradable and biocompatible biopolymer, has been widely researched for several applications in the field of biomaterials. Calcium phosphate ceramics stand out among the so-called bioceramics for their absence of local or systemic toxicity, their non-response to foreign bodies or inflammations, and their apparent ability to bond to the host tissue. Hydroxyapatite (HA) is one of the most important bioceramics because it is the main component of the mineral phase of bone. The aim of this work was to produce chitosan membranes coated with hydroxyapatite using the modified biomimetic method. Membranes were synthesized from a solution containing 2% of chitosan in acetic acid (weight/volume) via the solvent evaporation method. Specimens were immersed in a sodium silicate solution and then in a 1.5 SBF (simulated body fluid) solution. The crystallinity of the HA formed over the membranes was correlated to the use of the nucleation agent (the sodium silicate solution itself). Coated membranes were characterized by means of scanning electron microscopy-SEM, X-ray diffraction-XRD, and Fourier transform infrared spectroscopy-FTIR. The results indicate a homogeneous coating covering the entire surface of the membrane and the production of a semi-crystalline hydroxyapatite layer similar to the mineral phase of human bone.