doi:10.1038/nindia.2016.92 Published online 19 July 2016
Researchers have grown films based on silk protein on patterned polymer substrates. Since these films aid the regeneration of smooth muscle and endothelial cells, which could help form new blood vessels, they are potentially useful for replenishing damaged blood vessels in heart disease patients1.
Cardiovascular diseases are chiefly caused by damaged blood vessels, but existing synthetic tissue grafts cannot mimic the functions of human blood vessels and are expensive. To overcome these limitations, the researchers deposited the silk-protein-based films on microgrooved polymer substrates. They were non-toxic to blood and supported the growth of various vascular cells, including smooth muscle and endothelial cells.
Marker proteins such as calponin and alpha-smooth muscle actin, which are specific to smooth muscle cells, indicated the growth of smooth muscle cells. In addition, the muscle cells deposited collagen and elastin, indicating that the vascular graft grown on silk film was biomechanically stable.
The amount of collagen almost doubled in 10 days. The vascular graft could tolerate fluctuating pressures that are 10 times greater than those of physiological pressures and 5 times those of pathological pressures.
The silk-based scaffold induced negligible immune responses in mice, suggesting that it may also be safe to use in humans.
“In the future, this silk-based vascular graft could mimic the human-like circular and cylindrical vessel architecture and cell arrangement, yielding a way to replace damaged blood vessels through bypass heart surgery,” says Biman Mandal from the Indian Institute of technology, Guwahati.
1. Gupta, P. et al. Mimicking form and function of native small diameter vascular conduits using mulberry and non-mulberry patterned silk films. ACS Appl. Mater. Interfaces 8, 15874–15888 (2016)