Synthesis of biopolymers: proteins, polyesters, polysaccharides and polynucleotides

The synthesis of proteins, polyesters, polysaccharides and polynucleotides can be adapted to produce new macromolecular materials. Proteins of designed sequence, and with specific chemical functions, conferred by the incorporation of unnatural amino acids, have been prepared in genetically engineered bacteria. Polyesters, useful as biodegradable thermoplastics, have been made in bacterial hosts, and more recently, in transgenic plants. Polysaccharides, made either chemically or enzymatically, are being explored for biomedical applications, and synthetic polynucleotides could eventually serve as scaffolds in the construction of nanoscale materials.