ABSTRACTBasic fibroblast growth factor (bFGF), a protein, plays a key role in wound healing and blood vessel regeneration. However, most negative effects in vivo, or in vitro result from the over dosage of bFGF. Furthermore, it needs to keep the bFGF from protein denaturant. Thus, this study aims to develop a new delivery system based on silica nanoparticles (SiO2 NPs) dispersed in collagen patch for delivery of the bFGF in a local and prolonged manner. In this research, SiO2 NPs are used to encapsulate bFGF through a modified water-in-oil micro-emulsion. The bFGF-loaded nanoparticles afterwards are dispersed in the collagen-based matrix through a EDC cross-linking step. The in vitro release kinetics of SiO2 NPs - encapsulated bFGF with and without collagen matrix have been monitored through ELISA. In addition, the cytotoxicity of SiO2 NPs is investigated by studying the viability of Human Umbilical Vein Endothelial Cells (HUVEC) under the different concentrations of SiO2 NPs. It has found the average diameter (d) for SiO2 NPs encapsulating bFGF is 45 ± 8 nm with a loading efficiency of 72.5±3%. The maximum concentration of bFGF locally released from SiO2 NPs impregnated collagen matrix can be monitored after 30 days, while bFGF released from SiO2 NPs can be detected in 20 days. The further prolonged releasing after the nanoparticle-encapsulated bFGF laden collagen matrix is possibly due to the interaction between the nanoparticles and collagen matrix. In addition, the biocompatibility of the SiO2 NP has been investigated. We found that SiO2 NPs at the concentration of 50 μg/ml can still keep the cell alive. The results indicate that the nanoparticle-laden collagen matrix can locally deliver growth factor in a prolonged manner. This new delivery system may benefit to blood vessel regeneration and potentiate greater angiogenesis.
Vascular Tissue Engineering: Recent Advances in Small Diameter Blood Vessel Regeneration
