Enzymatic Polymerization of Poly(glycerol-1,8-octanediol-sebacate): Versatile Poly(glycerol sebacate) Analogues that Form Monocomponent Biodegradable Fiber Scaffolds

Abstract

A family of poly­(glycerol sebacate) (PGS) analogues were synthesized by Candida antarctica lipase B (CALB) catalysis to tailor biomaterial properties. Different fractions of glycerol (G) units in PGS were replaced by 1,8-octanediol (O) units. Poly­(glycerol-1,8-octanediol-sebacate), PGOS, synthesized by CALB catalysis with a 1:3 molar ratio of G to O units has M n and M w values of 9500 and 92,000, respectively. PGS undergoes fiber fusion during electrospinning, and cross-linked PGS rapidly resorbs when implanted. By decreasing the molar ratio of glycerol-to-octanediol from 1:1 to 1:4, the peak melting temperature (T m) increased from 27 to 47 °C. PGOS with 1:3 G to O units was electrospun into nanofibers without the need for a second component. The copolymer is semicrystalline and, when cross-linked, undergoes slow in vitro mass loss (3.5 ± 1.0% in 31 days) at pH 7.4 and 37 °C. Furthermore, PGOS cross-linked films have an elastic modulus of 106.1 ± 18.6 MPa, which is more than 100 times that of cross-linked PGS. New PGOS polymers showed tunable molecular weights, better thermal properties, and excellent electrospinnability. This work expanded PGS analogues’ function, making these suitable biodegradable polymers for various biomedical applications.

Review on the Impact of Polyols on the Properties of Bio-Based Polyesters

“…An alternative approach to PGS and PGS analog synthesis used as catalyst Candida antarctica lipase B (CALB) [ 68 , 69 ]. The CALB used is immobilized on a macroporous methyl methacrylate cross-linked resin.…”

“…N435-catalyzed synthesis of glycerol polyesters is usually performed by a one-pot synthetic method [ 70 , 71 , 72 ]. Lang et al described a family of poly(glycerol sebacate) (PGS) analogs where glycerol was replaced in part with octanediol (O) in bulk copolymerizations [ 68 ]. The new PGS analogs, PGOS polymers, showed tunable molecular weights with an M n and M w of 9500 and 92,000, as well as excellent electrospinning properties.…”

Poly(Glycerol Sebacate) in Biomedical Applications—A Review of the Recent Literature

“…[ 112,120,133,134 ] Lang et al. [ 135 ] showed the synthesis of PGS by CALB catalysis, whereby different fractions of glycerol units in PGS were replaced by 1,8‐octanediol units, enabling the fabrication of fibers via electrospinning without the need of a second component. [ 135 ]…”

Enzymatic Synthesis of Polyesters and Their Bioapplications: Recent Advances and Perspectives

“…However, low‐molecular‐weight polymers were obtained with intrinsic viscosity values of 0.115–0.189 dL g −1 . Likewise, poly(glycerol‐1,8‐octanediol sebacate) and poly(sorbitol‐1,8‐octanediol‐sebacate) [ 161 ] were recently developed by enzymatic polycondensation as analogues in biomedical uses of poly(glycerol‐sebacate). [ 162 ]…”

“…Similarly, Lang et al. [ 161 ] prepared high‐molecular‐weight PGSe from 1,8‐octanediol, glycerol, and sebacic acid using CALB as catalyst. The obtained polymers showed tunable molecular weights, better thermal properties, and excellent electrospinnability.…”