Silk Biomaterials-Mediated miRNA Functionalized Orthopedic Devices

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Orthopedic Engineering

Background:

• Silk-based bioresorbable materials show promise for orthopedic repairs.
• MicroRNAs regulate bone formation and offer potential for localized, transient therapeutics.
• Functionalizing silk devices can enhance control over bone regeneration.

Purpose of the Study:

• To investigate silk-based orthopedic devices for local delivery of anti-sense miR-214 (AS-miR-214).
• To assess the impact of AS-miR-214 delivery on osteogenic gene expression and differentiation in human mesenchymal stem cells.
• To evaluate the potential of functionalized silk devices for localized bone tissue engineering.

Main Methods:

• Silk devices were surface-coated with AS-miR-214.
• In vitro release kinetics of miRNA inhibitors were measured over 7 days.
• Human mesenchymal stem cells were seeded on AS-miR-214 silk films and control films.
• Osteogenic gene expression, cell viability, DNA content, alkaline phosphatase activity, and calcium deposition were analyzed.

Main Results:

• AS-miR-214 silk devices showed continuous miRNA inhibitor release for up to 7 days.
• Cells on AS-miR-214 silk films exhibited increased expression of osteogenic genes (ATF4, Osx, Runx2, Osteocalcin).
• Significantly higher alkaline phosphatase expression and calcium deposition were observed in AS-miR-214 treated cells compared to controls.
• Cells on AS-miR-214 silk films showed reduced cell viability and DNA content over 21 days.

Conclusions:

• Silk-based orthopedic devices can serve as a local delivery system for miRNA-based therapeutics.
• This approach enhances osteogenesis at the implant interface, supporting bone regeneration.
• Localized delivery of AS-miR-214 via silk devices offers a promising strategy for orthopedic tissue engineering while avoiding systemic side effects.