Biodegradable thermosensitive injectable PEG-PCL-PEG hydrogel for bFGF antigen delivery to improve humoral immunity

Abstract

In this contribution, a biodegradable and injectable thermosensitive poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) hydrogel system was successfully prepared for basic fibroblastic growth factor (bFGF) antigen delivery. bFGF encapsulated PECE hydrogel system (bFGF-hydrogel) is an injectable free-flowing sol at ambient temperature, and forms a non-flowing gel at physiological temperature acting as antigen depot. Furthermore, the cytotoxicity results showed that the PECE hydrogel could be regarded as a safe carrier, and bFGF could be released from the hydrogel system in an extended period in vitro. Otherwise, the immunogenicity of bFGF was improved significantly after encapsulated into the hydrogel. Strong humoral immunity created by bFGF-hydrogel was maintained for more than 14 weeks. Therefore, the prepared bFGF loaded PECE hydrogel might have great potential as a novel vaccine adjuvant for protein antigen.

Keywords::

• Biodegradable
• thermosensitive hydrogel
• basic fibroblast growth factor (bFGF)
• controlled release
• vaccine

Acknowledgements

This work was financially supported by National 863 Project (2007AA021902), the Research Fund for the Doctoral Program of Higher Education (200806100065), National Natural Science Foundation (NSFC20704027), New Century Excellent Talents in University, and Chinese Key Basic Research Program (2004CB518807).

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.