Solid silk fibroin is a bulk non-porous material that has been
recently investigated by our group1 as a promising material for
tissue engineering. This material produced by compression
molding starting from the well-known silk fibroin is extremely
resistant in dry conditions. However, in wet conditions tends
to plasticize, significantly reducing its compressive modulus. In
the present study, we investigated the possibility to chemically
crosslink the silk fibroin protein by the addition of Genipin
an aglycone extracted from a fruit that act as a crosslinker by
reacting with the amine side groups of the aminoacidic chain.
Genipin is quite general crosslinker for proteins and has been
proved to be non-cytotoxic2. This crosslinker has been added
to the fibroin previous to the compression molding, then
activated by sowing the resultant scaffold in water. The crosslinking
was optically visible by the soaking of from a partially
transparent yellowish color to blue and opaque, as results
of the reaction between Ginipin and the aminoacidic chain.
The compressive modulus has been then evaluated by the use
of a compression test, the thermal response by DSC and the
secondary structure by FTIR. The entire experiment has been
conducted by the use of a statistical method, called Design of
Experiment (DOE)3. DOE allowed us to model all the material
properties by empirical equations that relate the property of
interest to the parameters used to produce the material.