Fabrication of Biocompatible Electro-conductive Silk Films with Natural Compounds for Tissue Engineering Applications.
Abstract: In the
present study electro conductive natural compounds are incorporated in silk based films,
and the effects on film conductivity and dissolution are studied. Natural conducting
compounds melanin and riboflavin were blended with silk to increase conductivity. Other
compounds such as Fe(0) powder ferrofluid and NaCl solution also improved conductivity.
Film properties and dissolut... read moreion were studied for the different blends, and tuned using
addition of glycerol and horseradish peroxidase cross-linking. Techniques such as
electrospinning, doctor blade, spin coating, and paper-like film fabrication techniques
were also explored to generate films with controlled dimensions and properties. The
findings suggest that the incorporation of riboflavin along with NaCl and glycerol in
silk films, along with water vapor annealing results in semiconductor films. More
specifically, the two compositions of the films that exhibited highest conductivity
contain 2 % w/v silk, 20 % w/v glycerol, 2 % w/v polyethylene oxide (PEO), 30 % v/v
phosphate buffered saline (PBS) and 5 % w/v silk, 20 % w/v glycerol, 10 % w/v NaCl with
conductivities of 5.72*10-2 S/m and 5.96*10-2 S/m at 20 °C. When silk is doped with
riboflavin, NaCl, and glycerol, semiconducting behavior similar to drinking water
conductivity is observed. Mass loss studies of the films included the immersion of the
films for 7 days in 37° C in PBS. Film processing included samples that were heated
for 2 hours in 60 °C immediately after casting, as well as those cured at room
temperature. The results indicated that the heated samples provided the lowest mass loss
of approximately 27 %. In conclusion, the present study demonstrates the correlation
between composition and processing of silk films with their conductivity. These
semiconductive films have the potential to be applied in tissue engineering applications
such as nerve conduits, where conductivity plays an instrumental role in tissue
Thesis (M.S.)--Tufts University, 2015.
Submitted to the Dept. of Biomedical Engineering.
Advisor: David Kaplan.
Committee: Tim Atherton, and Qiaobing Xu.
Keyword: Materials Science.read less