Desenvolvimento de esferas de quitosana/Dysphania ambrosioides (L.) Mosyakin & Clemants para aplicação como biomaterial.

Abstract

Several biomaterials have been developed to fill in or reconstruct bone defects, among these the chitosan stands out due to its osteoinductive potential. Other substances have aroused the interest of the scientific community are the phytotherapics, in this group can be found the ‘mastruz’ (Dysphania ambrosioides (L.) Mosyakin & Clemants), for presenting the capacity of stimulating and accelerate bone repair. Thereby, this work aimed to develop and assess chitosan Dysphania ambrosioides (L.) Mosyakin & Clemants spheres for application as a biomaterial for bone regeneration. For this purpose the collection and botanical identification was carried out, and after the crude ethanolic extract (CEE) was produced, and its phytochemical characterization was performed. Having done this, spheres were made, by the ionotropic gelation method, using the Sodium tripolyphosphate (TPP) as a cross-linking agent and after, they were washed with distilled water and placed to dry in the oven. After this process, the chitosan spheres and chitosan with different concentrations of the EAB were characterized using Optical Microscopy (OM); Scanning Electron Microscopy (SEM); Fourier transformed infrared spectroscopy (FTIR); measurement of the diameter; in vitro Cytotoxicity, in vitro Enzymatic biodegradation and Compression tests. The result of the phytochemical characterization, demonstrated the presence of steroids, saponins and mainly flavonoids, in the crude ethanolic extract (CEE). The OM revealed the formation of well delimited spheres with a tendency of becoming darker as the EAB concentration increased; the SEM revealed the presence of a wrinkled external surface and an internal surface with a dense aspect due to the drying in the oven process. The chemical study performed by the FTIR identified all the bands typical characteristics of each material studied in this research; and in the produced spheres, the interaction of the TTP with the chitosan was found. The measures of the chitosan sphere’s diameters without the incorporation of the CEE (Q0) were smaller in comparison to the other groups: chitosan+5% of CEE (Q5), chitosan+10% of CEE (Q10) and chitosan+20% of CEE (Q20). All the samples were considered not cytotoxic; in relation to the biodegradation, in the presence of lysozyme, the spheres of all the groups presented mass loss at all the studied times, as for in the solution Phosphate Buffered Saline (PBS) a mass gain was observed in all the groups at the various studied moments. The Q0 group bared a greater compressive load and also deformed more, before fracturing, when compared to the Q5, Q10 and Q20 groups. This way it can be concluded that the methodology for the production of spheres was easy to carry out, therefore being reproducible and by means of the characterizations performed it was observed that CEE, made the spheres bigger, acted as a crosslinking agent of the chitosan, increasing the degradation time and also the supported compressive load and deformation suffered until the fracture. This way the incorporation of the CEE was favorable for the use of the spheres as a possible osteoinductor agent, seen as the products of their degradation may act with this purpose, being the spheres of the Q20 group the most indicated for areas with reduced anatomic dimensions.