The structure of the silk fibre has two components , a crystalline one incorporated in the semi - amorphous region . The crystalline section contains poly – ( Gly – Ala ) , and poly – Ala nano – domains , filling in 50 % of the volume . The weak Hydrogen bonds have the functionality to link the nano – domains , in 10 – 15 % of the volume . The overall fibre is a natural block copolymer , with the elastic capacity from 500 % to 1000 % , and with the tensile strength in the GPa magnitude .
The Araneidae , a garden spider , weaves the two - dimensional web to capture insects . The web silk for this spider does not break when the insect attaches . The retraction time of the extended web spiral is small , so that the silk does not attach to unwanted elements . The silk coated naturally with a hydroscopic glue , has increased elasticity . The researchers analyse the natural phenomenon , both in the absence , and in the presence of fluid . Figure 1 summarises two experiments , a and b , conducted with the same setup , in the laboratory . The stretching curve is red , and the retraction curve is blue .
Figure 1 . The force spectra of the silk web molecules for The Araneidae ( the orb – weaving spider ) .
Copyright ( 2003 ) Nature Publishing Group
The natural method to produce silk has yet many unknowns for the researchers . The spider silk produced naturally is in limited volume . A method to produce hand - made silk , similar to the spider silk , with lower tensile strength , is from the transgenic silk worms, and from the milk of the transgenic goats .
A suitable match between the material properties of biomaterials and the ones of the cardiac tissue may be improved . A scaffold may be electrospun with the silk solution , with or without the addition of extra cellular matrix solution .
References :
Becker N . , Oroudjev E . , Mutz S . , Cleveland J . P . , Hansma P . K . , Hayashi C . Y . , Makarov D . E . , Hansma H . G . ( 2003 ) “ Molecular nanosprings in spider capture – silk threads ” , Nature Materials , 2 , 278 - 283 .
