Elevating Postinjection Stability in Silk Nanofibril Hydrogels to Prevent Intervertebral Disc Degeneration

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Orthopedics

Background:

• Intervertebral disc degeneration is a widespread condition causing pain and disability.
• Injectable hydrogels offer a minimally invasive treatment but often lose mechanical integrity postinjection.
• Maintaining hydrogel mechanical and biochemical properties is crucial for therapeutic success.

Purpose of the Study:

• To develop a mechanically robust and antioxidative injectable hydrogel for intervertebral disc degeneration.
• To enhance silk-nanofibril-based hydrogels using *in situ* dopamine polymerization.
• To evaluate the therapeutic efficacy of the modified hydrogel in treating disc degeneration.

Main Methods:

• Fabrication of silk-nanofibril-based hydrogels.
• Enhancement via *in situ* polymerization of dopamine.
• Assessment of mechanical properties (modulus) and antioxidative capacity.
• In vitro cell studies and in vivo animal models for therapeutic evaluation.

Main Results:

• The developed hydrogel preserved modulus >1000 Pa postinjection, matching nucleus pulposus properties.
• Antioxidative properties were enhanced fourfold compared to the original hydrogel.
• Cell and animal studies confirmed significant therapeutic efficacy in treating intervertebral disc degeneration.

Conclusions:

• The silk-nanofibril-polydopamine hydrogel effectively addresses mechanical and biochemical challenges in treating degenerative disc disease.
• This injectable hydrogel presents a promising platform for subsequent therapeutic interventions.
• The study offers a novel design strategy for advanced injectable biomaterials for spinal applications.