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

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.

Retracted: A Photoclick Thiol‐Ene Collagen‐Based Hydrogel Platform for Skeletal Muscle Tissue Engineering

“…All samples revealed a J ‐shaped stress–strain curve during compression, reflecting the strain‐hardening behavior of collagen‐based materials. [ 6,28–30 ] At the same time, no mechanical break was observed following hydrogel compression up to 50%, unlike the case of previously reported UV‐cured methacrylated collagen networks. [ 28b,29 ] This observation agrees with the selectivity of the thiol‐ene crosslinking reaction, and the increased homogeneity (and compressibility) of the respective network architecture.…”

“…[ 6,28–30 ] At the same time, no mechanical break was observed following hydrogel compression up to 50%, unlike the case of previously reported UV‐cured methacrylated collagen networks. [ 28b,29 ] This observation agrees with the selectivity of the thiol‐ene crosslinking reaction, and the increased homogeneity (and compressibility) of the respective network architecture. [ 31 ] Given that the compression tests were carried out in the water‐swollen samples, swelling studies were therefore carried out to understand the behavior of this material in a near‐physiologic environment.…”

“…Considering the orthogonality of the presented thiol-ene reaction, these results, therefore, suggest that the presence of the PEG crosslinker mediates the diffusion and retention of water in the corresponding covalent networks, yielding higher values of SR compared to the case of PEG-free UV-cured RTC-based hydrogels. [28,29] To elucidate this point, the swelling kinetics of the thiol-ene networks were analyzed. The swelling of hydrogels typically includes i) the diffusion of water molecules, ii) the hydration and relaxation of polymer chains, and iii) the expansion of the polymer network.…”

Towards Polycaprolactone-Based Scaffolds for Alveolar Bone Tissue Engineering: A Biomimetic Approach in a 3D Printing Technique

“…One of the challenges in hard tissue engineering is the dev sources of CGI as an initial-stage matrix of biomimetic mineralis obtained from the skin tissue of cows [165], rat tails [166], and fish conducted on using plant collagen in BTE. However, it still requ opment of technology, in addition to plant collagen and the so-c The source of HA affects its chemical composition, structure, and properties [152].…”

“…One of the challenges in hard tissue engineering is the development of alternative sources of CGI as an initial-stage matrix of biomimetic mineralisation. Currently, CGI is obtained from the skin tissue of cows [165], rat tails [166], and fish [167]. Research is being conducted on using plant collagen in BTE.…”