Desenvolvimento de nanocompósitos de matriz polimérica biodegradável a base de agar reforçados com nanofillers de dióxido de titânio ou hidroxiapatita.

Abstract

Global trends to scientific advance in the development of new materials highlight the importance of using renewable a raw materials. In this study the objective was to develop a biodegradable matrix nanocomposites agar based reinforced with different concentrations of TiO2 and HA nanofillers, finding compositions that present mechanical and biological properties that allow the biotechnological application of these materials. Resins precursors previously synthesized with Ti cation were prepared through the polymeric precursor method (based on the modification of the Pechini method). Analogously resin precursor was obtained HA were subsequently deposited onto microporous membranes (pore diameter 0.2 μm) by means of a spin coating technique. Then, the material was subjected to heat treatment for two hours at 600 ° C to TiO2 and 800 ° C to HA. The resulting material after heat treatment had its surface modified by adding ethyl alcohol, tetraethoxysilane and acetic acid, which were subsequently evaporated in the oven (silanization process). The particles obtained were dispersed in an equal volume of distilled water to complete dissolution of the agar in ultrasound device and using concentrations of % 0.5, 1 and 2 of each material particle for obtaining the various nanocomposites. Dispersed material was added to the agar, remaining under stirring and heating to 100 ° C. Then it was added the sorbitol and glutaraldehyde crosslinking agents and plasticizers, respectively. The resulting material was poured onto the mold plate, remaining at room temperature until complete evaporation of the solvent. The resulting nanocomposites, as well as the polymeric material and the nanofillers were characterized by SEM and Ramam spectroscopy, which confirm the presence of the structures formed by the HA and TiO2 in the polymer matrix, as well as their nanometric dimensions. The nanocomposites as well as the nanofillers were tested for cytotoxicity, which demonstrated that the materials do not promote cell growth inhibition, not manifesting cytotoxicity when compared with a control group by means of cell growth. The antimicrobial activity of the films was evaluated by the agar diffusion test and diffusion over time for 2 and 5 days, pointing to the antimicrobial activity of HA nanocomposites with nanofillers. Mechanical testing demonstrated a significant increase in the modulus of elasticity of the composite material over the array control film formed by the agar. The data obtained in different experiments were statistically analyzed by two-way ANOVA and Tukey test, t test, ANOVA and supplementary Student-Newman-Keuls test and one-way ANOVA followed by Tukey test, where p < 0.05 in all cases, respectively.