Methacrylated Silk Fibroin Hydrogels: pH as a Tool to Control Functionality

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Tissue Engineering

Background:

• Photosensitive polymers enable in situ polymerization and 3D printing.
• Silk fibroin (SF) is a promising biomaterial for regenerative medicine due to its mechanical properties and cytocompatibility.
• Understanding SF assembly is key for designing effective SF-based materials.

Purpose of the Study:

• To investigate the impact of glycidyl-methacrylate-modified SF (SilkMA) solution pH on SilkMA hydrogel properties and secondary structure.
• To evaluate the influence of solution pH on hydrogel characteristics like rheology, mechanical strength, and swellability.
• To assess the effect of hydrogel pH on human dermal fibroblast viability and morphology.

Main Methods:

• Silk fibroin was modified with glycidyl methacrylate to create SilkMA.
• SilkMA solutions were prepared and tested at three different pH levels (5, 7, and 8).
• Hydrogel properties including rheology, compressive modulus, optical transmittance, and network swellability were analyzed. In vitro cell culture was performed using human dermal fibroblasts.

Main Results:

• Solution pH significantly affected SilkMA hydrogel rheological properties, compressive modulus, optical transmittance, and network swellability.
• The pH of the hydrogel did not influence the in vitro viability or morphology of human dermal fibroblasts.
• Tailoring SilkMA conformational structure is achievable by controlling solution pH.

Conclusions:

• Solution pH is a critical parameter for tuning SilkMA hydrogel properties and secondary structure for specific applications.
• Strict pH control during SilkMA hydrogel preparation is essential for reducing batch-to-batch variability and ensuring reproducibility.
• This study highlights the potential of pH modulation for developing functional SilkMA-based biomaterials for tissue engineering.