Prospects of Using Biocatalysis for the Synthesis and Modification of Polymers

Abstract

Trends in the dynamically developing application of biocatalysis for the synthesis and modification of polymers over the past 5 years are considered, with an emphasis on the production of biodegradable, biocompatible and functional polymeric materials oriented to medical applications. The possibilities of using enzymes not only as catalysts for polymerization but also for the preparation of monomers for polymerization or oligomers for block copolymerization are considered. Special attention is paid to the prospects and existing limitations of biocatalytic production of new synthetic biopolymers based on natural compounds and monomers from biomass, which can lead to a huge variety of functional biomaterials. The existing experience and perspectives for the integration of bio- and chemocatalysis in this area are discussed.

Keywords: biobased polymers; biocatalysis; biocatalytic monomer synthesis; biocompatible polymers; biodegradable polymers; enzymatic polymerization.

Figure 1

Number of publications versus years by search query “enzymatic polymerization” (by www.scopus.com, accessed on 01 March 2021).

Figure 2

Scheme of the formation of monomers during the oxidation of dopamine with molecular oxygen in the presence of laccase and the structure of the polymer chain of polydopamine, which includes several types of monomer units and additional ether bonds between the chains.

Figure 3

Schematic illustration of the laccase-catalyzed 3,4-ethylenedioxythiophene polymerization in the presence of polystyrene sulfonate (PSS) or DNA as a template.

Figure 4

Scheme of enzymatic polymerization of water-soluble (3-thienyl)-ethoxy-4-butyl sulfonate in the presence of horseradish peroxidase (HRP).

Figure 5

Scheme of biocatalytic preparation of a chondroitin polymer from a trisaccharide primer and monomers UDP-GlcA and UDP-GalNAc.

Figure 6

(a) Structure of the α/β-hydrolase motif of lipase B from Candida antarctica; (b) Candida antarctica lipase B active site (bold lines) compared to α/β-hydrolase family enzymes, including lipases and proteases (transparent lines). The view is taken from the inner side of catalytic amino acid residues shown by sticks; substrate-binding pocket of lipase B from Candida antarctica is shown by yellow surface. The figure was prepared using PyMol based on the crystal structure PDB ID: 1TCA.

Figure 7

Methods for obtaining polyesters. R, Rʹ—substituents in the molecules of dicarboxylic acid and diol; X—H, Me, Et.

Figure 8

Lipase-catalyzed lactone polymerization mechanism. R represents a group of the lactone molecule; Rʹ—H, alkyl.

Figure 9

Chemoenzymatic synthesis of polyamide based on a monomer obtained by radical addition of cysteamine to methyl oleate.

Figure 10

The structure of polyaspartic acid with alpha- and beta-units.

Figure 11

CALB-catalyzed polymerization of N-(6-hydroxyhexanoyl)-L-aspartate.

Figure 12

Synthesis of a copolymer of glutamic acid ethyl ester and nylon 4 using papain.

Figure 13

Phosphorylation of nanoparticles consisting of a chitosan–chondroitin sulfate complex using hexokinase.

Figure 14

Development of various aspects of the biocatalysis engineering concept for the production of polymers using enzymes: state of the art 2021. Existing developments are highlighted green, problems to be solved are highlighted yellow.

Figure 15

Scheme of the complex formation of a hydrogen bond donor (urea) with a chloride anion in a deep eutectic solvent based on a mixture of urea and choline chloride in a 2:1 molar ratio.

Figure 16

Scheme of the transesterification reaction between vinyl esters and alcohol. R¹ = n-C₁₁H₂₃, R² = _H-C₄H₉, _H-C₈H₁₇, _H-C₁₈H₃₇.

Figure 17

Chemoenzymatic synthesis of thermosensitive polymers based on star-like polyesters. NC—norcamphor, NCL—norcamphor lactone, CHMOAcineto—cyclohexanone monooxygenase from A. calcoaceticus, GDH—glucose dehydrogenase, Di-TMP—di-trimethylolpropane, ε-CL—ε-caprolactone, TBD—1,5,7-triazabicyclo[4.4.0]dec-5-ene, MSA—methanesulfonic acid, PCL—polycaprolactone, PNCL—poly(norcamphor lactone), CALB—lipase B from Candida antarctica, BMI—1,1′-(methylenedi-4,1-phenylene)-bis-maleimide, DA—Diels–Alder.

Figure 18

Chemoenzymatic synthesis of 2,5-diketomorpholine derivatives. R¹—hydroxy acid side chain radical, R²—amino acid side chain radical, DCC—N,N’-dicyclohexylcarbodiimide, DCU—N,N’-dicyclohexylurea.

Figure 19

The structures of 2,5-furandicarboxylic acid (FDCA) and 5-hydroxymethylfurfural (HMF).