Silk Sponges Promote Bone Repair in Rabbits
Scaffolds made of carbon nanofiber-reinforced silk protein may mimic nanoscale tissue structure to support bone regeneration.
Biomaterials play a crucial role in tissue engineering by serving as 3-D scaffolds for cellular attachment, proliferation and growth, ultimately leading to new tissue formation. A major goal in the field is to design porous scaffolds that mimic the architecture of tissue at the nanoscale while offering superior mechanical properties, biodegradability, minimal toxicity and design flexibility for personalized applications.
In a study published May 10 in the journal Biomaterials, Deboki Naskar and colleagues at the Indian Institute of Technology Kharagpur addressed this challenge by fabricating porous, 3-D sponges consisting of silk protein from the nonmulberry tropical tasar silkworm reinforced with carbon nanofiber.
Carbon nanofibers provide scaffolds with mechanical stiffness, while silk protein offers the advantages of excellent mechanical strength, biodegradability and flexibility for shaping the structures to meet patient-specific needs. Meanwhile, the pores of the scaffolds enhance nutrient transport and cell infiltration, promoting tissue formation and faster healing.
The researchers loaded their sponges with proteins called TGF-β1 and BMP-2—growth factors that play important roles in regulating bone repair and regeneration. The sponges showed sustained growth factor release; promoted cell attachment, growth and proliferation; and were not toxic to cells. In rabbits with thighbone defects, the sponges stimulated bone formation while producing no organ toxicity and minimal inflammatory responses.
According to the authors, carbon nanofiber-reinforced silk protein sponges offer numerous advantages and may mimic the nanoscale structure of bone tissue to support successful repair and regeneration.