Lyophilized Silk Sponges: A Versatile Biomaterial Platform for Soft Tissue Engineering.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Soft tissue engineering requires biomaterials with tunable mechanical and degradation properties.
• Silk fibroin is a promising natural polymer for biomedical applications.
• Controlling silk processing is crucial for achieving desired scaffold characteristics.

Purpose of the Study:

• To develop a silk biomaterial platform with highly tunable mechanical and degradation properties.
• To investigate the influence of silk molecular weight, concentration, and crystallinity on 3D scaffold formation and properties.
• To evaluate the in vitro and in vivo performance of silk scaffolds for soft tissue regeneration.

Main Methods:

• Preparation of lyophilized silk sponges under varied process conditions.
• Characterization of scaffold properties including molecular weight, concentration, crystallinity, morphology, mechanical strength, and degradation rate.
• Assessment of cell adhesion, proliferation, and infiltration using mesenchymal stem cells in vitro and subcutaneous implantation in vivo.

Main Results:

• Tuning silk molecular weight distribution enabled the formation of stable, highly porous 3D scaffolds at low silk concentrations (0.5% wt/v).
• Scaffold mechanical properties correlated with silk concentration, while degradation rate was influenced by beta-sheet content.
• Silk sponges supported mesenchymal stem cell adhesion and proliferation in vitro, and cell infiltration and scaffold remodeling in vivo.

Conclusions:

• Silk biomaterial platform offers tunable properties for soft tissue engineering.
• Controlled silk processing allows for the fabrication of versatile 3D scaffolds.
• These silk scaffolds demonstrate potential for skin, adipose, and neural tissue regeneration.