Although silk is commonly known as a fiber, dissolved silk protein has recently received significant attention for its use in creating biocompatible, biodegradable, and mechanically tough materials. We have discovered that reconstituted silk fibroin (RSF) is an excellent material for molding of nano- and micro-scale patterned features. RSF alleviates several problems seen with current polymers used for micromolding (e.g. PDMS), such as device collapse and feature rounding. We have fabricated stable silk nano- and microstructures with aspect ratios of ~10 (height to diameter) where PDMS collapses at ~3, and have measured feature replication down to 25 nm (PDMS is limited to 100 nm). We have furthermore shown that the RSF films are in an alpha-helical/random coil water-soluble state, but can also be crystallized into a beta-sheet and water insoluble conformation, giving them a broad range of bioresorbability. Silk’s toughness, flexibility, strength, and biodegradability make it an ideal candidate for silk-based tissue repair, drug delivery systems, and medical devices.
Project end date: 08/13/12