Assessment of biological interaction between chitosan, collagen, hydroxyapatite composite and ovine bone tissue

Author(s)

Geissiane de Moraes Marcondes

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Medicina Veterinária e Zootecnia (FMVZ/SBD)
• Defense date: 2014-12-12

Examining board members

André Luis do Valle de Zoppa; Roberto Pimenta de Pádua Foz Filho; Luis Claudio Lopes Correia da Silva

• Advisor: André Luis do Valle de Zoppa

Abstract

The lesions in limbs of large animals, with significant bone loss is a challenger for veterinarians. That\'s why frequentely only osteosynthesis are not able to fully guarantee satisfactory results. Because of this, many researchers have dedicated the projects to develop and study the biocompatibility of bone substitutes, including biomaterials, in order to assist bone repair. The composites with natural constituents such as chitosan, collagen and hydroyapatite may be an option, because they have similar structures with bone tissue. This study evaluated the biological behaviour of composite chitosan, collagen and hydroxyapatite following implantation in the ovine III / IV metacarpal bone. Six healthy female sheep Santa Inês were submitted to bilateral unicortical ostectomy (7 mm/ diameter) on the proximal aspect of the medial-dorsal surface of the III / IV metacarpal bone. One front limb was randomly selected for composite chitosan, collagen and hydroxyapatite implantation, while the contralateral limb was left untrated, not being filled. The animals were submited to daily physical examination during 60-day follow-up period. Radiographic, ultrasonographic and thermographic reassessment were performed on postoperative days seven, 14, 21, 28, 35, 42, 49 and 56. On postoperative day 60, the animals were reoperated and 3,55 mm biopsy fragment collected from the biomaterial bone or bone-new bone interface to histological evaluation by light and scanning electron microscopy. No changes in the physical examination (heart rate, respiratory rate or rectal temperature), or lameness over the 60 days, which could be related to the surgery or the presence of the implant were observed. Thermographic evaluation showed that temperature changed on the members with composite and control limb and they followed the same patterns, returning to physiological rate at the end of study. The radiographic and ultrasonographic evaluations have suggested that the control limb and limb with composite were in similar stages of bone healing. On the morphology by light microscopy, we observed a higher percentage of the new bone formation at the control limb when compared with the composite limb. However it was observed at the light and electron scanning microscopy, which showed osteoconductive biomaterial behavior and no adverse reactions to the implant, as scar tissue or foreign body reactions. With the results of this research, it can be concluded that the composite of chitosan, collagen and hidroxipatita when implanted in sheep bone tissue presents biocompatibility and osteoconductive characteristics. (AU)

• FAPESP's process: 13/00878-6 - Assessment of biological interaction between chitosan, collagen and hydroxyapatite and ovine bone tissue
• Grantee: Geissiane de Moraes Marcondes
• Support Opportunities: Scholarships in Brazil - Master