A Bio-inspired Latent TGF-β Conjugated Scaffold Improves Neocartilage Development

Area of Science:

• Biomaterials Engineering
• Tissue Engineering
• Regenerative Medicine

Background:

• Conventional cartilage tissue engineering uses high doses of active TGF-β, leading to detrimental tissue properties like swelling and hypertrophy.
• Native cartilage development involves controlled, localized TGF-β release from latent complexes (LTGF-β), promoting healthy matrix synthesis.
• Current methods struggle to replicate the controlled, physiologic dosing found in natural cartilage formation.

Purpose of the Study:

• To investigate a bio-inspired strategy using LTGF-β-conjugated scaffolds for improved neocartilage development.
• To compare the efficacy of LTGF-β scaffolds against conventional active TGF-β media supplementation (MS) at various doses.
• To assess the impact on neocartilage composition, structure, mechanical properties, and cell phenotype.

Main Methods:

• Bovine chondrocyte-seeded agarose constructs were cultured using LTGF-β scaffolds.
• Comparison groups included active TGF-β MS at 0.3 ng/mL (MS-0.3) and 10 ng/mL (MS-10), and a TGF-β-free control.
• Evaluated small (3x2 mm) and large constructs for mechanical properties, sGAG content, cell morphology, collagen distribution, and gene expression (COL-I, COL-X).

Main Results:

• LTGF-β scaffolds produced small neocartilage constructs with native-matched mechanical properties (800-925 kPa) and sGAG content (6.6%-7.1%).
• These constructs exhibited hyaline cartilage-like cell morphology and collagen distribution, with significantly reduced COL-I and COL-X expression.
• For large constructs, LTGF-β scaffolds minimized mechanical and biochemical heterogeneities compared to MS-0.3 and MS-10.

Conclusions:

• LTGF-β-conjugated scaffolds offer a superior strategy for neocartilage engineering by providing controlled TGF-β release.
• This approach enhances neocartilage quality, promoting a more native-like composition, structure, and cell phenotype.
• LTGF-β scaffolds hold promise for improving cartilage repair strategies, particularly for larger constructs.