Histologic and immunohistochemical evaluation of biocompatibility of castor oil polyurethane polymer with calcium carbonate in equine bone tissue

Abstract

OBJECTIVE To evaluate the efficacy of castor oil polyurethane polymer with calcium carbonate for use in a unicortical ostectomy on the dorsal surface of the third metacarpal bone of horses. ANIMALS 6 adult horses. PROCEDURES A unicortical ostectomy was created on the dorsal surface of both third metacarpal bones of each horse. Castor bean (Ricinus communis) oil polyurethane polymer with calcium carbonate was implanted into the ostectomy on 1 limb, and the ostectomy of the contralateral limb was left unfilled and served as a control sample. Ostectomy sites were evaluated histologically 120 days later. Biopsy specimens were obtained from the interface of bone and polymer or the interface of bone and newly formed tissue; specimens were processed for histomorphometric evaluation by use of light microscopy, immunohistochemical analysis, histochemical analysis, and transmission electron microscopy. RESULTS Osteoconductive activity of the biomaterial was confirmed by the presence of osteoblasts in the biopsy specimens. Absence of a chronic inflammatory response or foreign body reaction indicated biocompatibility. Expression of osteoblast markers was detected in the newly formed tissue. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that castor oil polyurethane polymer with calcium carbonate could be an acceptable compound for use as a bone substitute in horses with fractures in which bone filling is necessary.

Long-Term Evaluation of Poly(lactic acid) (PLA) Implants in a Horse: An Experimental Pilot Study

“…However, polymer implants must be biocompatible and bioabsorbable [ 4 , 8 ]. There are few studies on the use of polymer implants in horses, with most of them involving their use to repair bone fractures [ 13 , 14 , 15 , 16 , 17 ]. Therefore, polymeric materials represent potential alternatives to the use of autologous and heterologous grafts, which have been limited to fracture correction in equine medicine [ 13 , 15 ].…”

Association of Dental Pulp Stem Cells and Ricinus Bone Compound in a Model of Bone Defect

“…The biomaterial fulfilled the basic requirements for biocompatibility [16]. No significant inflammatory infiltrate was found in the samples and it served as support for newly-formed tissues, allowing the defect region to keep its architecture.…”

“…In any case, a potential tissue formation may represent a regenerative activity, which may be confirmed and better understood when investigated in combination with microscopic analyses, as carried out in this study. Association of analysis between optical microscopy and SEM allows assessment of the histological characteristic and tissue microstructures, identifying ossified regions and the interaction between the tissue and the biomaterial [16]. Although the assessment by SEM was qualitative, in case of doubt whether a structure was truly the result of bone regeneration, we performed analyses by EDS to identify and quantify the chemical elements present in the structure and whether those elements present in the right proportion corresponded to regenerating a bone tissue.…”

Plant-based Bone Grafting: The Future of Bone Healing

“…Polyurethane (CPR) found in the Ricinus communis plant has been studied for its biocompatibility and ability to stimulate bone regeneration. The effectiveness evaluation of castor bean polyurethane polymer with calcium carbonate by Nóbrega et al [70] for use in unicortical ostectomy on dorsal face of third equine metacarpal by histological and immunohistochemical techniques, showed osteoconductive activity of biomaterial, confirmed by the presence of osteoblasts in biopsy specimens. Also, absence of chronic inflammatory response or foreign body reaction indicated biocompatibility.…”