Poly(ethylene carbonate)s, part II11Part I: see Ref. [15].: degradation mechanisms and parenteral delivery of bioactive agents

Stoll, Georg H.; Nimmerfall, Fritz; Acemoglu, Murat; Bodmer, David; Bantle, Siegfried; Müller, Irene; Mahl, Andreas; Kolopp, Maryelle; Tullberg, Kjell

doi:10.1016/s0168-3659(01)00417-5

Cited by 56 publications

(57 citation statements)

References 34 publications

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“…This result has been confirmed by others for low molecular weight poly(TMC) degrading in phosphate-buffered saline [10]. Similar results have been reported for poly(ethylene carbonate) immersed in aqueous media with pH ranging from 1 to 12 by Stoll et al [11].…”

Section: Introductionsupporting

confidence: 88%

“…In contrast to these results, Stoll et al reported that poly(ethylene carbonate) was unaffected by the presence of hydrolytic enzymes in aqueous media [11]. They showed that, in vitro, poly(ethylene carbonate) did not degrade in the presence of hydroxyl radicals, but did degrade in a surface erosion manner in the presence of superoxide anion.…”

Section: Introductionmentioning

confidence: 87%

“…They showed that, in vitro, poly(ethylene carbonate) did not degrade in the presence of hydroxyl radicals, but did degrade in a surface erosion manner in the presence of superoxide anion. Acemoglu et al, examined the in vivo degradation of both poly(ethylene carbonate) and poly(TMC) and found that poly(ethylene carbonate) degraded much faster [11,12]. On the basis of the results of Stoll et al, it was proposed that the in vivo degradation of poly(ethylene carbonate) and poly(TMC) implants proceeds by oxidation via superoxide anion radicals and that the slower oxidation of poly(TMC) was due to the more stable sixmembered ring of trimethylene carbonate that is proposed to form as a result of degradation [11,12].…”

Section: Introductionmentioning

confidence: 99%

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The role of oxidation and enzymatic hydrolysis on the in vivo degradation of trimethylene carbonate based photocrosslinkable elastomers

et al. 2009

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Section: Introductionsupporting

confidence: 88%

Section: Introductionmentioning

confidence: 87%

Section: Introductionmentioning

confidence: 99%

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The role of oxidation and enzymatic hydrolysis on the in vivo degradation of trimethylene carbonate based photocrosslinkable elastomers

et al. 2009

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“…Oxidation by reactive oxygen compounds secreted by macrophages is considered to be the main cause of degradation of polycarbonates in vivo. [27,28,32,33] Low Viscosity Poly(trimethylene carbonate) for Localized Drug Delivery . .…”

Section: In Vivo Degradationmentioning

confidence: 99%

Low Viscosity Poly(trimethylene carbonate) for Localized Drug Delivery: Rheological Properties and in vivo Degradation

Timbart

Tse

Pang

et al. 2009

Macromolecular Bioscience

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The purpose of this study is to examine the potential of low-molecular-weight poly(trimethylene carbonate) for localized delivery for acid-sensitive drugs. Poly(trimethylene carbonate) of various molecular weights is prepared by ring-opening polymerization initiated by octan-1-ol and co-initiated/catalyzed by tin 2-ethylhexanoate. The resultant polymers are amorphous with low glass transition temperatures and viscosities at 37 degrees C that permit their injection through an 18(1\2) G 1.5'' needle. Their biocompatibility and the influence of the molecular weight on the rate of degradation are assessed in vivo through subcutaneous implantation in rats over 40 weeks. The polymers are well tolerated in vivo, and degrade in a fashion dependent on their initial molecular weight. For very low initial molecular weight (620 Da) and for high initial molecular weight (2,400 Da), polymer mass loss is a result of dissolution of the soluble low molecular chains from the bulk. This is contrasted by the results obtained for an intermediate initial molecular weight (1,600 Da), for which polymer mass loss is a result of both dissolution and enzymatic hydrolysis or oxidation as a result of reactive species secreted by activated macrophages at the implant surface.

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“…[12][13][14][15] Poly(ethylene carbonate) (PEC) is a unique polycarbonate known to possess a surface degradation mechanism via superoxide anions produced by the adhesion of polymorphonuclear leucocytes and macrophages. [16][17][18] However, it is difficult to obtain PEC via ROP because of the positive enthalpy of ethylene carbonate (EC) homopolymerization, and the polymerization of EC usually proceeds at a high temperature (> 100 C) with partial decarboxylation and the elimination of carbon dioxide, which mostly depends on the choice of the initiator. 1 One convenient method for preparing polymers containing EC units is the ring-opening copolymerization of EC with other cyclic monomers such as e-caprolactone and L-lactide.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and properties of random copolymers of 2,2‐dimethyltrimethylene carbonate and ethylene carbonate catalyzed by lanthanide tris(2,6‐di‐tert‐butyl‐4‐methylphenolate)

Liu

et al. 2009

J of Applied Polymer Sci

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Random copolymers of 2,2-dimethyltrimethylene carbonate and ethylene carbonate (EC) were synthesized with lanthanide tris(2,6-di-tert-butyl-4-methylphenolate)s [Ln(DBMP) 3 ; Ln ¼ La, Nd, Sm, or Dy] as catalysts, among which La(DBMP) 3 showed the highest activity. Poly(2,2-dimethyltrimethylene carbonate-co-ethylene carbonate)s [poly(DTC-co-EC)]s with high molecular weights were prepared at room temperature and characterized with 1 H-NMR and size exclusion chromatography. The thermal behavior and crystalline properties of the poly(DTC-co-EC)s were analyzed with differential scanning calorimetry, thermogravimetric analysis, and X-ray diffraction. The crystallinity and melting temperatures of the poly(DTC-co-EC)s both decreased with increasing EC content in the copolymers. The mechanical properties of these copolymers were also investigated with dynamic mechanical analysis and tensile strength measurements, which revealed that a reduction of the glass-transition temperature and great enhancement of the tensile properties could be achieved with higher EC contents. These improvements in the thermal and mechanical properties indicate potential applications in biomedical research for novel polycarbonates.

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Poly(ethylene carbonate)s, part II11Part I: see Ref. [15].: degradation mechanisms and parenteral delivery of bioactive agents

Cited by 56 publications

References 34 publications

The role of oxidation and enzymatic hydrolysis on the in vivo degradation of trimethylene carbonate based photocrosslinkable elastomers

The role of oxidation and enzymatic hydrolysis on the in vivo degradation of trimethylene carbonate based photocrosslinkable elastomers

Low Viscosity Poly(trimethylene carbonate) for Localized Drug Delivery: Rheological Properties and in vivo Degradation

Synthesis and properties of random copolymers of 2,2‐dimethyltrimethylene carbonate and ethylene carbonate catalyzed by lanthanide tris(2,6‐di‐tert‐butyl‐4‐methylphenolate)

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