Hydrolysis of biodegradable polymers by superoxide ions

Lee, K. H.; Won, Chee-Youb; Chu, Chih‐Chang; Gitsov, Ivan

doi:10.1002/(sici)1099-0518(19990915)37:18<3558::aid-pola2>3.0.co;2-4

Cited by 27 publications

(17 citation statements)

References 30 publications

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“…Earlier studies have shown that poly(D,L-lactide) [34] and photopolymerized PTMC networks [19] can be degraded in tetrahydrofuran (THF) containing KO 2 /18-crown-6 ether. Stoll and co-workers have used alkaline aqueous superoxide solutions to investigate the degradation of poly(ethylene carbonate) [24].…”

Section: Erosion By Reactive Oxygen Speciesmentioning

confidence: 98%

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Macrophage-mediated erosion of gamma irradiated poly(trimethylene carbonate) films

et al. 2009

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Section: Erosion By Reactive Oxygen Speciesmentioning

confidence: 98%

“…In the degradation of polyesters [34] and polycarbonates [19,23], nucleophilic attack of the superoxide anion radical produces anionic end groups. In the case of PTMC, these react with the carbonate carbonyl groups in the polymer backbone and H 2 O to form 1,3-propane diol and carbon dioxide.…”

Section: Erosion By Reactive Oxygen Speciesmentioning

confidence: 99%

Macrophage-mediated erosion of gamma irradiated poly(trimethylene carbonate) films

et al. 2009

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“…Many factors affect the degradation rate. Besides environmental conditions, such as temperature, the degradation rate is strongly dependent on the film thickness, 1 additives such as monomer, 2 basic compounds, 3 acid drugs 4 or superoxide ion, 5 and catalyst such as SnOct 2 or zinc metal, [6][7][8][9] etc. The molecular architecture, [10][11][12][13] hydrophilicity, [14][15][16] reasonable crosslink, 17,18 and surface modification 19,20 have vital influence on the degradation properties, too.…”

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confidence: 99%

Synthesis, Characterization, and Degradation Behaviors of End-Group-Functionalized Poly(trimethylene carbonate)s

Zhuo

2003

Polym J

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KEY WORDSPolycarbonate / Biodegradable Material / End-Group Effect / Biodegradable polymers are under investigation for biomedical, pharmaceutical applications, etc. Degradability is one of their important characters. Many factors affect the degradation rate. Besides environmental conditions, such as temperature, the degradation rate is strongly dependent on the film thickness, 1 additives such as monomer, 2 basic compounds, 3 acid drugs 4 or superoxide ion, 5 and catalyst such as SnOct 2 or zinc metal, 6-9 etc. The molecular architecture, 10-13 hydrophilicity, 14-16 reasonable crosslink, 17,18 and surface modification 19,20 have vital influence on the degradation properties, too.End-group effect is demonstrable on the degradation rate. 21 It was shown that poly(lactide-co-glicolide) (PLGA) with a free carboxyl group at the polymer terminus (uncapped PLGA) degrades faster than PLGA with a hydrophobic alkyl ester linkage at the polymer terminus (capped PLGA). 22 Lee 21 synthesized various end-group-functionalized, such as OH-, NH 2 -, Cl-, or COOH-terminated polylactides (PLAs) and found that the COOH end group plays a crucial role in the hydrolysis degradation in both alkaline and acidic medium. Protection of OH end group results in a substantial retarded degradation. 23 Polyanhydrides capped with fatty terminals also show a significantly slow degradation and drug release rate. 24 Linear aliphatic polycarbonates, such as poly(1,3-trimethylene carbonate) (PTMC), have been shown to be potential for use as medical implants and for drugdelivery applications. 25 But they degrade unexpectedly slow. 10 Many efforts have been made to enhance their degradation rate. Copolymers of PTMC were synthesized for adapting to applications requiring different degradation rates and mechanical properties. 10,[26][27][28][29] Pendant hydroxyl groups have been introduced to improve the hydrophilicity and hence the degradability. 30 Since end groups have special effect on degradation rate, end-group functionalized polycarbonates will have different degradation rate. Because the polymers of multiarm architecture have a higher end-group concentration than linear polymers of the same molecular weights, the multiarm structure can strengthen the end group effect. Some researchers have synthesized the OH-terminated PTMC by ring-opening polymerization (ROP), but the degradability has not been involved up to now. 31 In the present study, we synthesize PTMC with different number of arms terminated by hydroxyl group or carboxylic group and study the degradability of such end-group-functionalized PTMCs preliminarily. EXPERIMENTAL 1,3-Trimethylene carbonate (TMC) was synthesized according to the reported method. 32 All other regents were treated just before use. Synthesis of OH-Terminated PTMC (OH-PTMC)The ring-opening polymerizations (ROP) of TMC initiated by alcohols are illustrated in Scheme 1. These polymerization reactions were carried out in the melt bulk. All reaction reagents were used just after treated. A known amount of TMC was charged ...

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“…Biomaterials implanted in mice have been shown to generate a similar production of reactive oxygen species in vivo 39 . These ROS include molecules such as superoxide (O 2 −), hypochlorite (ClO−), hydrogen peroxide (H 2 O 2 ), and the hydroxyl radical (OH · ) and all have been shown to have degradative capacity for biomaterials, specifically towards poly(D,L-lactic) acid 40,41 and polyurethanes 42 . The current body of literature points to ROS as a highly likely mediator of the commonly observed accelerated in vivo degradation phenomenon.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

“…(7) was regressed to experimental data taken from 43 . The diffusion and chain reaction of reactive species (eq.…”

Section: Ros Parameter Estimationmentioning

confidence: 99%

A systems approach to modeling drug release from polymer microspheres to accelerate in vitro to in vivo translation

Knab

Little

2015

Journal of Controlled Release

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Hydrolysis of biodegradable polymers by superoxide ions

Cited by 27 publications

References 30 publications

Macrophage-mediated erosion of gamma irradiated poly(trimethylene carbonate) films

Macrophage-mediated erosion of gamma irradiated poly(trimethylene carbonate) films

Synthesis, Characterization, and Degradation Behaviors of End-Group-Functionalized Poly(trimethylene carbonate)s

A systems approach to modeling drug release from polymer microspheres to accelerate in vitro to in vivo translation

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