Development of protein delivery scaffolds with a separate drug carrier system for bone tissue regeneration

Abstract

This study aimed to develop new drug delivery scaffolds to be used in tooth socket and investigate fabricating parameters which affect the desired characteristics of scaffold. Scaffolds of hyaluronan-gelatin (HA-Gel) blends and 1,6- diisocyanatohexane extended poly(1,4-butylene succinate) (PUSu-DCH) were fabricated by freeze-drying and particulate-leaching technique respectively. The α-chitin whiskers reinforced HA-Gel scaffolds exhibited variable behaviours by the different amount of whiskers adding. 2, 10, and 20-30% of whiskers improved strength, growth of bone cells, thermal resistance and biodegradation respectively whereas internal architecture and water absorption capability were not affected. The scaffold decelerated the release of crude bone protein at -30-40% for the first 24 h when gelatin microspheres were integrated as a separate delivery device though the ionic interaction between molecule of protein and gelatin was not occurred by the absorptive protein loading method. The PUSu-DCH scaffold fabricated with salt particles of 200-400 μm at 35 wt% exhibited better mechanical, physical and biological properties than those at 25, 30 or 40 wt%, and controlled the release of serum protein as low as 20% of total within the first 24 h, under the condition of direct mix the protein with gelatin during the process of microspheres fabrication. The controlled release was simultaneously influenced by ionic interaction between molecules of gelatin and protein, proportion of HA and gelatin in the HA-Gel coating matrix and scaffolds’ pore sizes. The designed scaffolds promisingly illustrated both scaffolding and controlled releasing functionalities for bone tissue regeneration.