Interfacing bioactive glass with silk fibroin: a soft matter approach to tunable mechanics and enhanced biocompatibility

Abstract

Tissue-engineering scaffolds must balance mechanical compatibility with biological performance to support effective tissue regeneration. Bioactive glass (BG), valued for its strength and bone-bonding ability, often suffers from high stiffness, risking stress shielding. To address this limitation, we hybridized BG with silk fibroin (SF), a soft, biocompatible protein, to create (3-glycidyloxypropyl)trimethoxysilane (GPTMS)-crosslinked BG–SF scaffolds with tunable mechanics and enhanced cellular interactions. Fabricated via the sol–gel technique with varying BG-to-SF ratios, the scaffolds demonstrated increased porosity with higher SF content, positioning SF as a natural alternative to chemical porogens. Mechanical testing revealed that incorporating SF reduced BG stiffness, improved flexibility, and enhanced toughness, aligning the scaffold properties with those of native tissues. Fatigue testing confirmed greater durability in SF-enriched scaffolds, while degradation studies highlighted controllable rates conducive to tissue regeneration. Remarkably, as little as 10 wt% SF increased cell survival by 6.5-fold in biocompatibility assays. These findings underscore the synergy between BG and SF, presenting a soft matter strategy for designing scaffolds with customizable properties for tissue-engineering applications.