Characterization of Gelatin Methacrylate (GelMA) Hydrogels for Cartilage Tissue Engineering Applications

Abstract

Articular cartilage, a tissue that is particularly known for its self-repairing
deficiency, is a major challenge in regenerative medicine. Gelatin Methacrylate
(GelMA) is a multifunctional and biocompatible hydrogel, which has attracted
much attention as a potential scaffold material for cartilage tissue engineering.
This paper gives a detailed characterization of GelMA hydrogels with regard to
the effect of polymer concentration on their physicochemical and biological
properties. We performed an in-depth analysis of GelMA at concentrations of 5%,
10% and 15% (w/v) and their mechanical strength, swelling kinetics, degradation
rates and porous architecture. Additionally, we have synthesized and critically
reviewed optimal parameters for 3D bio-printing of constructs based on GelMA
for cartilage regeneration. Our results show that the mechanical properties are
significantly improved with an increase in the concentration of GelMA from 5%
to 15%, and the compressive modulus has been increased from 3.3 +- 0.5 kPa to
30.0 +- 4.0 kPa. This enhancement, however, comes with a decrease in porosity,
swelling ratio and degradation rate. While no one GelMA formulation reproduced
the mechanical properties of native articular cartilage, a 10% (w/v) concentration
of GelMA, with optimized 3D bioprinting parameters, appears to be a well
balanced formulation. It provides a good compromise between mechanical
stability and microenvironment that allows the viability, proliferation, and
chondrogenesis of cells. This critical review highlights the opportunities of the
GelMA as a highly tunable and promising platform in which effective and
clinically relevant cartilage repair and regeneration strategies can be developed.