Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Release kinetics of VEGF165 from a collagen matrix and structural matrix changes in a circulation model | Kleinheinz et al. Head Face Medicine 2010 6 17 http content 6 1 17 HEAD FACE MEDICINE RESEARCH Open Access Release kinetics of VEGF165 from a collagen matrix and structural matrix changes in a circulation model Johannes Kleinheinz 1 Susanne Jung1 Kai Wermker1 Carsten Fischer2 and Ulrich Joos1 Abstract Background Current approaches in bone regeneration combine osteoconductive scaffolds with bioactive cytokines like BMP or VEGF. The idea of our in-vitro trial was to apply VEGF165 in gradient concentrations to an equine collagen carrier and to study pharmacological and morphological characteristics of the complex in a circulation model. Methods Release kinetics of VEGF165 complexed in different quantities in a collagen matrix were determined in a circulation model by quantifying protein concentration with ELISA over a period of 5 days. The structural changes of the collagen matrix were assessed with light microscopy native scanning electron microscopy SEM as well as with immuno-gold-labelling technique in scanning and transmission electron microscopy TEM . Results We established a biological half-life for VEGF165 of 90 minutes. In a half-logarithmic presentation the VEGF165 release showed a linear declining gradient the release kinetics were not depending on VEGF165 concentrations. After 12 hours VEGF release reached a plateau after 48 hours VEGF165 was no longer detectable in the complexes charged with lower doses but still measurable in the 80 pg sample. At the beginning of the study a smear layer was visible on the surface of the complex. After the wash out of the protein in the first days the natural structure of the collagen appeared and did not change over the test period. Conclusions By defining the pharmacological and morphological profile of a cytokine collagen complex in a circulation model our data paves the way for further in-vivo studies where additional biological side effects will have to be considered. VEGF165 linked to collagen .
