Influence of β- Phosphate - Chitosan in the development of angiogenesis on scaffolds implanted in critical size bone defects. An in-vivo study in rats

Objectives:
Critical bone size deffects are one of the most complex procces in tissue engineering. In one hand the lack of vascularization in early stages of healing proccess avoid an spontaneous recovery. On the other hand, the use of bone substitutes such allografts, xenografts and alloplastic materials, are strongly related to blood supply and then, produces bone regeneration.
Any biomaterials used to produce tissue bone regeneration could be fail in its intention due to poor or lack in vascularization conditions. Although, there are some techniques of pre-vascularizaed autologous bone grafts to tackle this disadvantage, the morbidity of this procedures increase the patients risk, cost, complexicity and time recovery. The aim of this proposal is the design and development of chtiosan scaffolds (natural polimer with healing properties) using tissue engineering technologies. Animal Etics committee regulations have been accomplished, endorsed by the Animal Ethical committe in Universidad del Valle, Cali-Colombia.


OBJECTIVES
Evaluation of the capacity to stimulate angiogenesis in ceramic scaffolds (bioactive quitosano), implanted in critical size boine defects (CSD) of Wistar rats.
Methods: Β- tricalcium phosphate Chitosan scaffolds were implanted in cavities of 5 mm diameter in parietal bones of 12 Wistar rats. The follw up period was established at 20, 40 and 60 days. Analysis were performed using histochemical tests and electron microscopy were made scanning and transmission.
Results: An increase in blood vessel formation and distribution of cells around the scaffolds was observed (centripetal shape). Furthermore, this blood vessels increase tends to disappear and recover the normal architecture of the parietal bone. Histomorphometric results were analyzed by Tukey's test with a lower p-value 0 05.
Conclusions: The material have been effective in the stimulation of angiogenesis process and the development of new vessels. This phenomenon follow the biological steps presented in natural scarring