Issue 40, 2010

An entropy–elastic gelatin-based hydrogel system


Gelatin is a non-immunogenic and degradable biopolymer, which is widely applied in the biomedical field e.g. for drug capsules or as absorbable hemostats. However, gelatin materials present limited and hardly reproducible mechanical properties especially in aqueous systems, particularly caused by the uncontrollable partial renaturation of collagen-like triple helices. Therefore, mechanically demanding applications for gelatin-based materials, such as vascular patches, i.e. hydrogel films that seal large incisions in vessel walls, and for induced autoregeneration, are basically excluded if this challenge is not addressed. Through the synthesis of a defined chemical network of gelatin with hexamethylene diisocyanate (HDI) in DMSO, the self-organization of gelatin chains could be hindered and amorphous gelatin films were successfully prepared having Young's moduli of 60–530 kPa. Transferring the crosslinking reaction with HDI and, alternatively, ethyl lysine diisocyanate (LDI), to water as reaction medium allowed the tailoring of swelling behaviour and mechanical properties by variation of crosslinker content while suppressing the formation of helices. The hydrogels had Young's moduli of 70–740 kPa, compressive moduli of 16–48 kPa, and degrees of swelling of 300–800 vol%. Test reactions investigated by ESI mass spectrometry allowed the identification and quantification of reaction products of the crosslinking reaction. The HDI crosslinked networks were stabilized by direct covalent crosslinks (ca. 10 mol%), supported by grafting (50 mol%) and blending of hydrophobic oligomeric chains. For the LDI-based networks, less crosslinked (3 mol%) and grafted species (5 mol%) and much higher amounts of oligomers were observed. The adjustable hydrogel system enables the application of gelatin-based materials in physiological environments.

Graphical abstract: An entropy–elastic gelatin-based hydrogel system

Supplementary files

Article information

Article type
30 Mar 2010
10 Jun 2010
First published
10 Aug 2010

J. Mater. Chem., 2010,20, 8875-8884

An entropy–elastic gelatin-based hydrogel system

G. Tronci, A. T. Neffe, B. F. Pierce and A. Lendlein, J. Mater. Chem., 2010, 20, 8875 DOI: 10.1039/C0JM00883D

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.