Influence of Short-Range Scrambling of Monomer Order on the Hydrolysis Behaviors of Sequenced Degradable Polyesters

Abstract

The extent to which small changes in monomer sequence affect the behaviors of biological macromolecules is studied regularly, yet the dependence of bulk properties on small sequence alterations is underexplored for synthetic copolymers. Investigations of this type are limited by the arduous syntheses required, lack of scalability, and scarcity of examples of polymer systems that are known to exhibit sensitive sequence/property dependencies. Our group has previously explored the hydrolysis behaviors of a library of sequenced poly(lactic-co-glycolic acid)s and found a strong correlation with the L−G sequence. To investigate the degree to which properties are dominated in this system by relatively short-range sequence changes, we have incorporated precisely sequenced and mildly "scrambled" L−G oligomers into cyclic macromonomers and subjected them to entropy-driven ring-opening metathesis polymerization, a method that we have recently shown produces polymers with molecular weight control and sequence preservation. The resulting polymers, which have identical composition and molecular weight, were hydrolyzed. Molecular weight decrease, mass loss, thermal behaviors, and film/surface characteristics were monitored to reveal stark differences in degradation behaviors despite the confinement of errors within a short segment. Article pubs.acs.org/Macromolecules

Application of 3D-Printed, PLGA-Based Scaffolds in Bone Tissue Engineering

“…As an artificial bone graft, its biodegradability is directly related to bone formation, which is of great significance. For PLGA, LA:GA ratio, molecular weight, and end-group of molecular chain all affect the degradation rate of PLGA scaffolds [ 19 , 20 , 21 ]. The main degradation modes of PLGA are hydrolysis and ester bond autocatalytic degradation.…”

Sequence‐Controlled Alternating Copolyesters Synthesis via Selective Ring‐Opening Polymerization

“…The thermal and hydrolysis properties of copolyesters are affected by the sequence structure. [9][10][11][12][13][14] In the past decades, metal-based initiators have been widely applied for the stereoselective and regioselective ROP of lactones, which can be used to control the sequence-controlled copolyesters. The stereoselectivity and regioselectivity of initiator/catalyst depend on the confined space formed by the catalytic metal center, monomer, and chain end of the polymer.…”

A Versatile Synthetic Platform for Discrete Oligo- and Polyesters Based on Optimized Protective Groups Via Iterative Exponential Growth

“…As an important category of commodity materials, aliphatic polyesters have been widely used in the field of packing, , tissue engineering, , and other bio-medical applications, due to their attractive attributes of sustainability, biodegradability, and biocompatibility. Additionally, their properties can be modulated by changing the structure and composition of repeating ester units. , Even though discrete polyesters provide ideal models for deep understanding of fundamental physical properties, developing efficient, versatile, and scalable synthetic approach toward discrete polyesters still remains a challenge. To date, most discrete aliphatic polyesters were prepared via the IEG strategy by a judicious choice of the orthogonal protective groups for hydroxyl and carboxyl groups, as well as the following efficient esterification conditions (Scheme A). ,,,,− In 1996, Seebach et al have prepared a discrete polyester of ( R )-β-hydroxybutanoic acid (PβHB), having 128 repeating units (128 mer) and MW > 11 kDa via the IEG strategy .…”

“…Additionally, their properties can be modulated by changing the structure and composition of repeating ester units. 41,42 Even though discrete polyesters provide ideal models for deep understanding of fundamental physical properties, developing efficient, versatile, and scalable synthetic approach toward discrete polyesters still remains a challenge. To date, most discrete aliphatic polyesters were prepared via the IEG strategy by a judicious choice of the orthogonal protective groups for hydroxyl and carboxyl groups, as well as the following efficient esterification conditions (Scheme 1A).…”