Nanocompósitos à base de hidroxiapatita e nanotubos de carbono como reforço em biopolimero heterólogo de fibrina derivado do veneno de serpente para regeneração óssea

Abstract

Fibrin sealants (BHF), developed from human hematological derivatives, mimic physiological clots, being widely used in general, cosmetic and postoperative surgeries due to their hemostatic and adhesive action. BHF developed from the venom of Crotalus durissus terrificus (rattlesnake) is a heterologous thrombin-like derivative that converts fibrinogen into fibrin. As it is a natural product, in gel form, biodegradable, bioabsorbent, non-toxic and non-immunogenic. On the other hand, hydroxyapatite nanocomposites (nHAp) and carbon nanotubes (NTCs), produced by chemical synthesis assisted by the ultrasound technique, present bioactivity, are not cytotoxic and have a bactericidal effect. The aim of the present work is to evaluate the mixture of hydroxyapatite-based nanocomposites and carbon nanotubes with fibrin sealant as agents in the process of accelerating bone regeneration. The production of the nanocomposites consisted, firstly, in the synthesis of NTCs with multiple walls, followed by their functionalization to the O2 plasma and purification with an acid bath. With this material ready, the composite of nHAp with NTC was produced. Then, this material was added to the BHF and the physicochemical characterization of this mixture was carried out. The pellets formed by these mixtures were analyzed and photographed under scanning electron microscopy (SEM). These mixtures were also tested in MC3T3-E1 cell cultures to verify their toxicity. For this purpose, osteoblast cells were cultured and cell viability was verified using the alamarBlue® e LIVE/DEAD® Viability/Cytotoxicity technique. Experiments were also carried out in rats, inducing bone defect in tibias and verifying bone repair. All data were analyzed using the normality test, and the parametric results were submitted to the two-way ANOVA complemented by Tukey's post-test (p≤0,05). The results showed that there was a good homogeneous distribution of the mixtures and that the most suitable mixture for in vitro tests is that of BFH+nHAp and 1% and 2% carbon nanotubes. The mixture is not cytotoxic and promoted neoformation in the fracture area, demonstrating osteogenic potential in bone fractures.