Analysis of osteointegration, in vitro cytotoxicity and in vivo toxicity of polimetilmetacrilate and poliurethane porous cements

• Grant number: 12/18965-0
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2013
• End date: October 31, 2015
• Field of knowledge: Health Sciences - Medicine - Surgery
• Principal Investigator: Edgard Eduard Engel
• Grantee: Edgard Eduard Engel
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil
• Associated researchers: Francisco José Albuquerque de Paula ; José Batista Volpon ; Laura Tiemi Okano ; Marcello Henrique Nogueira Barbosa ; María Sol Brassesco Annichini ; Paulo Donato Frighetto

Abstract

Absorbable or not absorbable porous Cements are alternatives in the treatment of large bone defects. Its production by addition of the effervescent agents' sodium bicarbonate and citric acid has been studied from a physical standpoint and shown its applicability. But there is no information on the effect of citrate released during the effervescent reaction on hemostasis. The possible formation of toxic reagents or in vivo osseointegration has not been studied as well. The castor oil-based polyurethane cements are resorbable and seem to be good candidates to be tested in the porous form. Objective: Evaluate the formation of toxic elements during the production of porous cements based on polymethylmethacrylate (PMMA) or castor oil polyurethane with elements effervescent. To evaluate the effects on hemostasis of citrate produced during the reaction between the effervescent elements. Evaluate the ability of osseointegration of these cements. Methods: Three types of porous cement will be produced by mixing PMMA, Poliquil or Bioósteo castor oil polyurethane with effervescent elements and compared with each other and with a control. Cement samples for laboratory evaluations, rabbits for short-term analysis (1 week) and sheep for long-term analysis (3 and 6 months) will be used as experimental models. Analysis includes: the chemical composition after the reaction, the acute in vitro toxicity in cell cultures, the effect of citrate on hemostasis in rabbits underwent cements implantation, inflammatory reaction caused by cement in rabbits (acute) and sheep (chronic), chronic systemic toxicity in sheep's organs 6 months after implantation and osseointegration reared in large bone defects under load conditions in sheep. Histology, histomorphometry and computed microtomography will be used to evaluate osseointegration. (AU)