Fibrillar osteoid niche mimicry through inclusion of visco-elastic and topographical cues

ABSTRACT: Given the clinical need for osteoregenerative materials incorporating controlled biomimetic and biophysical cues, a novel norbornene-modified gelatin was developed with a degree of substitution of 169% compared to the number of amines present in pristine gelatin type B. It is, to the best of our knowledge, the highest substitution degree reported to date for norbornene-functionalised gelatin. Thiol-ene crosslinking exploiting thiolated gelatin as cell-interactive crosslinker resulted in networks with high (>95%) norbornene conversion. Comparing the number of physical crosslinks present, the degree of hydrolytic degradation upon modification, the network density as well as the chemical crosslinking type, the novel thiol-ene network was benchmarked against conventional gelatin-based systems in terms of the effect of biophysical cues, more specifically visco-elastic and topographical properties, affecting osteogenesis both in 2D and in 3D via a biofabrication strategy. The novel thiol-ene network outperformed conventional gelatin-based networks in terms of osteogenesis, as evidenced in 2D dental pulp stem cell seeding assays, resulting from the presentation of both a local (substrate elasticity, 25-40 kPa) and a bulk (compressive modulus, 25-45 kPa) osteogenic substrate modulus in combination with adequate fibrillar cell adhesion spacing to optimally transfer traction forces from the fibrillar ECM (as evidenced by mesh size determination with the rubber-elasticity theory) and resulting in a 1.5- and 1.7-fold increase in alkaline phosphatase activity and calcium production respectively as osteogenic markers (compared to the gold standard gelatin methacryloyl (GelMA)). Dental pulp stem cell encapsulation in extrusion-based biofabricated 3D constructs also showed a favorable response towards the novel thiol-ene network thanks to the combination of its RGD mobility (as observed from proteomic analysis), stress relaxation and substrate rigidity (bulk compressive modulus of 11-30 kPa) to enable a 1.5- and 7-fold increase in alkaline phosphatase activity and calcium production respectively as osteogenic markers (compared to the gold standard GelMA).

INSTRUMENT(S): Q Exactive Plus

ORGANISM(S): Bos Taurus (bovine)

TISSUE(S): Skin

SUBMITTER: BRAY FABRICE  

LAB HEAD: Fabrice Bray

PROVIDER: PXD039644 | Pride | 2024-03-13

REPOSITORIES: Pride