A biomimetic collagen/heparin multi-layered porous hydroxyapatite orbital implant for in vivo vascularization studies on the chicken chorioallantoic membrane.

ABSTRACT

BACKGROUND: The vascularization of an orbital implant is a key issue for reducing complications, such as exposure and infection. METHODS: Here, we developed a facile layer-by-layer assembly approach to modify porous hydroxyapatite (pHA) orbital implants with five collagen (COL)/heparin (HEP) multilayers. RESULTS: SEM characterization showed that the average pore size of the pHA/(COL/HEP)5 scaffold was 316.8 ± 77.1 µm. After being coated with five COL/HEP multilayers, the mechanical strength was improved compared with that of the pHA scaffolds. The in vitro assay displayed that the pHA scaffolds covered with COL/HEP multilayers resulted in a larger number of human umbilical vein endothelial cells after being cultured for 14 days. The macroscopic evaluation and semi-quantitative vascular density analysis of the chicken chorioallantoic membrane assay showed that the pHA/(COL/HEP)5 scaffolds resulted in more intense angiogenesis than the pHA scaffolds. CONCLUSIONS: These studies demonstrate that the biomembrane-mimicking coating of COL/HEP multilayers is a simple and effective strategy to endow combined biological performances of pHA orbital implants and to potentially reduce implant-related complications.