Cell encapsulation and delivery by coaxial electrosprayed microspheres for tissue engineering

Abstract

Different approaches including cell-based or scaffold-based tissue engineering are used for tissue regeneration and they can be combined for achieving optimal clinical outcomes. In cell-based tissue engineering, suitable vehicles for delivering living cells are required. In this study, coaxial electrospray was investigated for cell delivery for scaffold-based tissue engineering. Polymers such as sodium alginate (SA) were used to firstly fabricate cell-free microspheres. A polymer solution was fed into outer capillary and PBS was fed into inner capillary of a coaxial spinneret to produce core-shell structured microspheres. SA underwent post-spray crosslinking treatment. After process optimization, PBS was replaced by aqueous cell suspensions of human umbilical vein endothelial cell (HUVEC) or human aortic smooth muscle cell (HASMC) in coaxial electrospray for making cell-encapsulated microspheres at high (1×107/mL) or low (5×106/mL) cell density. Cell-encapsulated microspheres had spherical shapes but different diameters. Cell release from microspheres was achieved when SA shell broke down in 10 minutes after being treated with 0.055M Na-citrate solution. High cell loading efficiency was obtained. Cells exhibited high viability both after cell encapsulation and after cell release. Desirable cell encapsulation and delivery can be achieved via these microspheres for tissue engineering.