In situgrafting MPEG on the surface of cell-loaded microcapsules for protein repellency

The protein repelled alginate-graft-BAT/chitosan/MPEG-norbornene (ABCPN) hydrogel microcapsules were achieved by copper-free click reaction between azides from BAT and alkylenes from norbornene. The MPEG modified polyelectrolyte microcapsules showed significant resistance to immune protein adsorption and good biocompatibility in vivo. Moreover, the mild reaction condition made it feasible that the microcapsules could be formed and modified in situ even when live cells were encapsulated, and precluded the damage cause by other violent modifications methods to transplanted cells or tissues.