Biomateriais porosos produzidos da blenda de HPMC e óxido de grafeno contendo bioativos para restauração óssea bucal

Abstract

Several bioactive molecules can be carried in porous biomaterials. The polysaccharides extracted from the mushroom Agaricus blazei Murill (PAb) stand out due to their anti-inflammatory, antitumor, and gastroprotective activities. In addition to macromolecules, recent studies use Atorvastatin Calcium (ATV), a drug that acts as an attenuator of inflammatory processes in wound healing and bone restoration. Therefore, the objective of the research was to develop porous biomaterials of the hydrogel/scaffold type, based on the physical interactions between graphene oxide (GO) and hydroxypropylmethylcellulose (HPMC), to carry the aforementioned bioactive molecules to aid bone restoration oral. Physical and chemical characterizations were carried out using FTIR, XRD, TG, SEM, and EDS, to determine the structure of the starting materials and the developed biomaterials and to understand their morphology and chemical composition. Tests such as GO cytotoxicity, porosity, and viscosity of the blends were carried out to determine the suitability of the biomaterials regarding the parameters required for in vivo application. In addition, an in vivo tooth extraction test was performed, applying HPMC hydrogels containing OG, PAb, and ATV directly into the sockets to promote an improvement in buccal bone restoration. As for the rheological behavior of the produced hydrogels, an adaptation to the rheological model of Ostwald de Waele was noticed, with correlation values (R2) of 0.99. The flow index values (n) remained lower than one (1.0), indicating a non-Newtonian nature of the pseudoplastic type for the hydrogels. As for the scaffolds produced by the freeze-drying method, a highly porous structure can be seen, both by the SEM images and the ethanol absorption test. It is estimated that GO has a low cytotoxic potential against human neutrophils, and can be considered safe for use at concentrations below 100 ppm. From the in vivo tooth extraction test, macroscopic and radiographic analyzes identified a significant improvement (p > 0.05) in the hemimaxillas of rats that received treatment with hydrogels containing only GO (0.75 mg mL-1), as well as the other two containing PAb (1.0% m V-1) and ATV (1.2% m V-1), compared to the control group. Therefore, given the results obtained in the analyzes and tests, the developed biomaterials have adequate parameters of porosity, cytotoxicity, rheology, and morphology, in addition to presenting in vivo results that demonstrate that these materials are promising for bone regeneration.