Calcium Cross-Linked Cellulose Nanofibrils: Hydrogel Design for Local and Controlled Nitric Oxide Release

Area of Science:

• Biomaterials Science
• Nanotechnology
• Regenerative Medicine

Background:

• Nitric oxide (NO) is crucial for wound healing, promoting vasodilation and tissue regeneration.
• Local NO delivery via NO donors in biocompatible matrices is promising for biomedical applications.
• Cellulose nanofibrils (CNF) offer a stable, tunable matrix for controlled release systems.

Purpose of the Study:

• To develop robust cellulose nanofibril (CNF) hydrogels for controlled *in situ* nitric oxide (NO) release.
• To investigate the effect of CNF concentration on NO release kinetics and hydrogel properties.
• To assess the potential of CNF-based hydrogels for biomedical applications requiring precise NO delivery.

Main Methods:

• Isolation of CNF from sugar cane bagasse, characterized by high aspect ratio and colloidal stability.
• Preparation of CNF hydrogels via ionic cross-linking with Ca2+.
• Incorporation of *S*-nitrosoglutathione (GSNO) as an *in situ* NO donor.
• Measurement of NO release rates and hydrogel mechanical properties (elastic moduli).

Main Results:

• Stable, nontoxic CNF hydrogels with tunable mechanical properties (300–3000 Pa) were fabricated.
• NO release rate from GSNO was successfully controlled by CNF concentration, decreasing from 1.61 to 0.40 mmol·L−1·h−1 with increasing CNF content (0.3 to 1.0 wt %).
• Hydrogel mesh size, influenced by CNF concentration, regulated NO stabilization over 16 hours.

Conclusions:

• CNF hydrogels provide a tunable platform for controlled nitric oxide delivery.
• The developed hydrogels demonstrate significant potential for biomedical applications, particularly in wound healing and regenerative medicine.
• Precise control over NO release kinetics can be achieved by tailoring CNF concentration.