Effect of Mammalian Tissue Source on the Molecular and Macroscopic Characteristics of UV-Cured Type I Collagen Hydrogel Networks

TL;DR

This study compares collagen from different mammalian tissues to determine their suitability for UV-cured hydrogels, finding bovine tissue as a promising source with favorable properties for medical applications.

Contribution

It provides a comparative analysis of collagen sources, highlighting bovine tissue as a viable and scalable option for UV-cured hydrogel production.

Findings

Bovine collagen produced hydrogels with high gel content (>97%).

Porcine collagen resulted in higher swelling ratios and lower mechanical strength.

In-house rat tail collagen showed comparable gel content to bovine collagen.

Abstract

The tissue source of type I collagen is critical to ensure scalability and regulation-friendly clinical translation of new medical device prototypes. However, the selection of a commercial source of collagen that fulfils both aforementioned requirements and is compliant with new manufacturing routes is challenging. This study investigates the effect that type I collagen extracted from three different mammalian tissues has on the molecular and macroscopic characteristics of a new UV-cured collagen hydrogel. Pepsin-solubilised bovine atelocollagen (BA) and pepsin-solubilised porcine atelocollagen (PA) were selected as commercially available raw materials associated with varying safety risks and compared with in-house acid-extracted type I collagen from rat tails (CRT). All raw materials displayed the typical dichroic and electrophoretic characteristics of type I collagen, while significantly decreased lysine content was measured on samples of PA. Following covalent functionalisation with 4-vinylbenzyl chloride (4VBC), BA and CRT products generated comparable UV-cured hydrogels with significantly increased averaged gel content (G > 97 wt.%), while the porcine variants revealed the highest swelling ratio (SR = 2224 +/- 242 wt.%) and an order of magnitude reduction in compression modulus (Ec = 6 +/- 2 kPa). Collectively, these results support the use of bovine tissues as a chemically viable source of type I collagen for the realisation of UV-cured hydrogels with competitive mechanical properties and covalent network architectures.