ORIGINAL PAPER Functionally modified gelatin microspheres as a growth factor’s delivery system: development and characterization N. Adhirajan • R. Thanavel • N. Naveen • T. S. Uma • Mary Babu Received: 29 May 2013 / Revised: 17 November 2013 / Accepted: 11 February 2014 Ó Springer-Verlag Berlin Heidelberg 2014 Abstract One of the advances in biotechnology has been the development of the capability to produce large quantities of highly purified polypeptides and proteins. Unfortunately, the circulatory half-lives of many of these agents are short, usually of the order of minutes and the time required for a response in tissues is usually long compared to the half-life. Hence, there is always demand for polymeric systems which can deliver the proteins for prolonged period and also to protect the molecules from degradation. The present work was attempted to develop heparin-functionalized gelatin microspheres (HMS) to deliver heparin-binding growth factors particularly for wound-healing appli- cations. The heparin conjugation was carried out using EDC/NHS coupling protocol. Heparin-binding EGF-like growth factor (HB-EGF) was loaded in HMS and its in vitro release behaviour in an environment with or without proteases was studied. The bioac- tivity of the HB-EGF released from the microspheres was assessed using NIH 3T3 mouse embryonic fibroblast culture. The extent of heparin modification was found to be 1.97 lmol/g of HMS and demonstrated significant protection against enzymatic degra- dation and sustained release of HB-EGF for more than 10 days. The bioactivity of HB- EGF released from the HMS was retained during the observed release period. The HMS was also found to be non-toxic as determined by calcein AM fluorescent staining. The overall study suggests that the HMS could be used as a growth factor’s delivery com- ponent in tissue engineering scaffolds particularly for wound-healing applications. N. Adhirajan (&)  R. Thanavel Department of Pharmaceutical Biotechnology, KMCH College of Pharmacy, Kalapatti Road, Kovai Estate, Coimbatore 641048, Tamil Nadu, India e-mail: adhirajan@gmail.com N. Adhirajan  N. Naveen  T. S. Uma Bioproducts Division, Central Leather Research Institute, Chennai, Tamil Nadu, India N. Adhirajan  M. Babu Biomaterials Division, Central Leather Research Institute, Adyar, Chennai, Tamin Nadu, India 123 Polym. Bull. DOI 10.1007/s00289-014-1108-3