Vinyl Copolymers with Faster Hydrolytic Degradation than Aliphatic Polyesters and Tunable Upper Critical Solution Temperatures

Well-defined, semi-degradable polyester/polymethacrylate block copolymers, based on ε-caprolactone (CL), d,l-lactide (DLLA), glycolide (GA) and N,N′-dimethylaminoethyl methacrylate (DMAEMA), were synthesized by ring-opening polymerization (ROP) and atom transfer radical polymerization. Comprehensive degradation studies of poly(ε-caprolactone)-block-poly(N,N′-dimethylaminoethyl methacrylate) (PCL-b-PDMAEMA) on hydrolytic degradation and enzymatic degradation were performed, and those results were compared with the corresponding aliphatic polyester (PCL). The solution pH did not affect the hydrolytic degradation rate of PCL (a 3% Mn loss after six weeks). The presence of a PDMAEMA component in the copolymer chain increased the hydrolysis rates and depended on the solution pH, as PCL-b-PDMAEMA degraded faster in an acidic environment (36% Mn loss determined) than in a slightly alkaline environment (27% Mn loss). Enzymatic degradation of PCL-b-PDMAEMA, poly(d,l-lactide)-block-poly(N,N′-dimethylaminoethyl methacrylate) (PLA-b-PDMAEMA) and poly(lactide-co-glycolide-co-ε-caprolactone)-block-poly(N,N′-dimethylaminoethyl methacrylate) (PLGC-b-PDMAEMA) and the corresponding aliphatic polyesters (PCL, PLA and PLGC) was performed by Novozyme 435. In enzymatic degradation, PLGC degraded almost completely after eleven days. For polyester-b-PDMAEMA copolymers, enzymatic degradation primarily involved the ester bonds in PDMAEMA side chains, and the rate of polyester degradation decreased with the increase in the chain length of PDMAEMA. Amphiphilic copolymers might be used for biomaterials with long-term or midterm applications such as nanoscale drug delivery systems with tunable degradation kinetics.

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Studies of the Hydrolytic Degradation of Some Aliphatic Polyesters

Studies in Polymer Science - Biodegradable Plastics and Polymers ◽

10.1016/b978-0-444-81708-2.50060-9 ◽

1994 ◽

pp. 519-527 ◽

Cited By ~ 3

Author(s):

J.V. Seppälä ◽

R.M.H. Malin

Keyword(s):

Hydrolytic Degradation ◽

Aliphatic Polyesters

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A Simple Route to Aqueous Suspensions of Degradable Copolymer Nanoparticles from Radical Ring-Opening Polymerization-Induced Self-Assembly (rROPISA)

10.33774/chemrxiv-2021-4hk17 ◽

2021 ◽

Author(s):

Chen Zhu ◽

Stephanie Denis ◽

Julien Nicolas

Keyword(s):

Self Assembly ◽

Ring Opening ◽

Hydrolytic Degradation ◽

Structural Diversity ◽

Radical Ring ◽

Aliphatic Polyesters ◽

Degradable Polymer ◽

Aqueous Suspensions ◽

Research Fields ◽

Synthetic Strategy

Degradable polymer nanoparticles are almost exclusively obtained by formulation of preformed degradable polymers, such as aliphatic polyesters, thus resulting is very low nanoparticle concentrations and limited structural diversity. On the other hand, many different vinyl polymers can be obtained by polymerization in aqueous dispersed media, but their non-degradability limits their use especially in the biomedical field. Herein, we combined the best of both worlds by developing a two-step radical ring-opening copolymerization-induced self-assembly (rROPISA) process, allowing to generate aqueous suspensions of narrowly dispersed, degradable vinyl copolymer nanoparticles at 15 wt.% solid contents, containing cyclic ketene acetal (CKA) units in the nanoparticle core. This strategy relied on rROPISA in DMF, followed by a simple transfer step to water. It was successfully applied to the three main CKAs used in rROP and yielded nanoparticles of ~80–215 nm in diameter with tunable amount of CKA up to 21 mol.%. Successful incorporation of ester groups in the copolymers was demonstrated by hydrolytic degradation of both the copolymers and the nanoparticles. The nanoparticles’ cytocompatibility was then established by cell viability assays and cell morphology observation with three representative healthy cell lines. Not only this synthetic strategy could be of great potential for drug delivery applications, but it can also be beneficial to other research fields to yield more environmentally friendly materials involving the use of latexes, such as paints or coatings.

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Effect of antibacterial drugs on hydrolytic degradation of aliphatic polyesters

Physics and Chemistry of Materials Treatment ◽

10.30791/0015-3214-2021-4-58-66 ◽

2021 ◽

Vol 4 ◽

pp. 58-66

Author(s):

E. N. Antonov ◽

◽

A. G. Dunaev ◽

L. I. Krotova ◽

V. K. Popov ◽

...

Keyword(s):

Release Kinetics ◽

Hydrolytic Degradation ◽

Dosage Forms ◽

Polymer Scaffolds ◽

Polymer Molecular Weight ◽

Aliphatic Polyesters ◽

Polymer Carriers ◽

Visible Effect ◽

Bioresorbable Polymer ◽

Phosphate Buffered Saline

Supercritical fluid encapsulation of gentamicin, levofloxacin and tetracycline into bioresorbable polylacto-co-glycolic acid (PLGA) scaffolds at 20 wt. % was performed by PLGA plasticization in supercritical carbon dioxide with its subsequent foaming. The effect of incorporated antibiotics on the rate of PLGA hydrolytic degradation, determined by weekly measurements of the polymer molecular weight and gravitational masses decrease during 6 weeks scaffolds incubation in a phosphate-buffered saline (PBS) solution, has been studied. Measurements of pH of PBS containing scaffolds were carried out accordingly. The rate constants of PLGA hydrolysis for different scaffolds comprising various drugs were determined. It was shown that tetracycline significantly reduces the rate of PLGA degradation compared to the rate of control (pure polymer) scaffolds degradation. At the same time, the presence of gentamicin and levofloxacin in the scaffolds had no visible effect on their degradation. These results enhancing the predicting potential for considered antibiotics release kinetics from bioresorbable polymer carriers into bioactive media, what is necessary for the development of highly efficient sustained-release dosage forms.

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