Efeitos do estrôncio, local e sistêmico, na regeneração de defeitos ósseos críticos

Abstract

Strontium (Sr) is a trace element non-essential, chemically and physiologically similar to calcium (Ca), which has a double effect on bone metabolism, by stimulating bone formation by osteoblasts, the other by inhibiting bone resorption by osteoclasts. Therefore, the research that correlates the Sr with the bone tissue has become more prominent after the development of the drug strontium ranelate (RS), used to reduce the risk of fractures in osteoporotic patients. With this, studies began to evaluate the action of Sr on bone regeneration, both systemically and locally, in individuals/animals without osteoporosis. Thus, the objective of this study was to evaluate the effect of Sr, through the local and systemic use, of strontium-containing nanostructured hydroxyapatite/alginate in the regeneration of critical bone defects. A sample of 30 animals was used and distributed for the composition of three groups, evaluated at 15, 30 and 60 postoperative days: GnHASr – critical bone defect filled with microspheres of 1% strontium-containing nanostructured hydroxyapatite/alginate (nHASr1%) and without enteral administration; GnHASrAlg – critical bone defect without implantation of biomaterial and enteral administration of 50% strontium-containing nanostructured hydroxyapatite/alginate (nHASrAlg); and GC – critical bone defect without implantation of biomaterial and without enteral administration (control group). The histological results demonstrated, in all biological points and experimental groups, a reactive bone neoformation restricted to the edges of the defect and filling of the residual area by fibrous connective tissue. Biochemical analyzes showed that plasma concentrations of Sr presented values close to the control group. Therefore, Sr both locally and systemically did not favor the increment of regeneration of critical bone defects.