Synthetic biopolymer

Synthetic biopolymers are artificially produced versions of natural biopolymers, created through non-biological chemical processes. These human-made materials come in various chemical forms, such as polysaccharides, glycoproteins, peptides, proteins, polyhydroxoalkanoates, and polyisoprenes. Producing these high-molecular-weight polymers is inherently difficult. Additional challenges arise from the specific three-dimensional structures of natural biopolymers, which are often essential for their function but hard to replicate synthetically.

Nevertheless, chemical synthesis is highly desirable because it avoids problems like low natural abundance, complex purification steps, and inconsistent quality found in natural sources. Examples made by purely chemical routes include cis-1,4-polyisoprene (synthetic rubber) and trans-1,4-polyisoprene (synthetic gutta percha), both produced via coordination polymerization with Ziegler-Natta catalysts. Polyhydroxoalkanoates like poly(3-hydroxybutyrate) and poly(hydroxyvaleric acid) are made through polycondensation or polyaddition. Low-molecular-weight polylactide and other polyglycolides can also be chemically synthesized.

Oligonucleotides and polynucleotides (DNA or RNA) are obtained via established chemical methods. Many proteins have been chemically synthesized, notably through native chemical ligation, which joins short unprotected peptides; this technique has yielded proteins such as insulin-like growth factor 1, the precursor of Aequorea green fluorescent protein, and the influenza A virus M2 membrane protein. Chemoenzymatic routes combine chemical and biological catalysts. Examples include polyhydroxoalkanoates and polyesters made using lipase enzymes, as well as heparin, heparan sulfate, other glycosaminoglycans, and plant glycans.

Polysaccharides like cellulose, amylose, chitin, and their derivatives are also produced this way. Natural and non-natural polynucleotides can be synthesized using ligase- or polymerase-based methods with template-assisted polymerization. Biopolymers made through genetic engineering or recombinant DNA technology are not classified as synthetic biopolymers; they are instead called artificial biopolymers (e.g., artificial proteins or artificial polynucleotides). Like their natural counterparts, synthetic biopolymers are used in many fields, including commodity materials, drug delivery, tissue engineering, and therapeutic and diagnostic applications.