Comparative Evaluation of Fibrin for Bone Regeneration in Critical Size Calvarial Defects

Abstract

Natural biopolymers such as collagen and fibrin have beenwidely used in bone regenerative applications. Despite thefrequent use, their comparative biological propertiesis arelargely unknown. In a previous study, we found thesuperiority of fibrin to collagen in the adsorption of serumproteins and the proliferation and differentiation of culturedosteoblasts. In this study, we used an in vivo model toevaluate how effectively fibrin supports bone regeneration,as compared with collagen. Collagen and fibrin were placedin critical size defects made on rat calvarial bones. Comparedwith collagen, fibrin supported substantially more new bonetissue formation, which was confirmed by micro-CTmeasurement and histological analyses. The cells in theregenerative tissues of the fibrin-filled defects wereimmunostained strongly for Runx2, while collagen-placeddefects were stained weakly. These in vivo resultsdemonstrate that fibrin is superior to collagen in supporting bone regeneration.