Thermo-responsive hydrogels based on branched poly(L-lactide)-poly(ethylene glycol) copolymers

I.W. Velthoen, Edze J. Tijsma, E.J. Tijsma, Pieter J. Dijkstra, Jan Feijen

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

10 Citations (Scopus)

Abstract

Branched poly(L-lactide)-poly(ethylene glycol) (PLLA-PEG) block copolymers were synthesized from trifunctional PLLA and amine functionalized methoxy poly(ethylene glycol)s. The copolymers in water formed hydrogels that showed thermo-responsive behavior. The hydrogels underwent a gel to sol transition with increasing temperature as determined with the vial tilting method and oscillatory rheology. For all copolymers, the transition temperature increased with increasing copolymer concentration. The transition temperature of corresponding branched copolymers also increased with increasing PEG molecular weight, and surprisingly decreased with increasing molecular weight of the PLLA branches. In general, the gel-sol transition is explained by disruption of micellar or aggregate interactions because of partial dehydration and shrinkage of the PEG chains. An increase in the molecular weight of the PLLA branches led to the formation of micelles and aggregates as observed with DLS at low concentrations. It is speculated that the non-uniform size distribution and possible crystallization of longer PLLA blocks may have a negative effect on the formation of micellar packing upon gelation, allowing the disruption of micellar or aggregate interactions to occur at lower temperatures. The transition temperature of the gels could be tuned closely to body temperature by varying the concentration of the solution or the molecular weight of the PEG block and the PLLA blocks, which implies that these polymers may be used as injectable systems for in-situ gel formation.
Original languageUndefined
Title of host publicationSelected contributions from the conference: 2nd meeting of the international network (bio)degradable polymers from renewable resources
EditorsS. Penczek, S. Slomkowski
Place of PublicationWeinheim
PublisherInternational Union of Pure and Applied Chemistry
Pages13-27
DOIs
Publication statusPublished - 18 Nov 2008

Publication series

Name
PublisherInternational Union of Pure and Applied Chemistry
Number1
Volume272
ISSN (Print)1022-1360
ISSN (Electronic)1521-3900

Keywords

  • METIS-254514
  • IR-69410

Cite this

Velthoen, I. W., Tijsma, E. J., Tijsma, E. J., Dijkstra, P. J., & Feijen, J. (2008). Thermo-responsive hydrogels based on branched poly(L-lactide)-poly(ethylene glycol) copolymers. In S. Penczek, & S. Slomkowski (Eds.), Selected contributions from the conference: 2nd meeting of the international network (bio)degradable polymers from renewable resources (pp. 13-27). Weinheim: International Union of Pure and Applied Chemistry. https://doi.org/10.1002/masy.200851202
Velthoen, I.W. ; Tijsma, Edze J. ; Tijsma, E.J. ; Dijkstra, Pieter J. ; Feijen, Jan. / Thermo-responsive hydrogels based on branched poly(L-lactide)-poly(ethylene glycol) copolymers. Selected contributions from the conference: 2nd meeting of the international network (bio)degradable polymers from renewable resources. editor / S. Penczek ; S. Slomkowski. Weinheim : International Union of Pure and Applied Chemistry, 2008. pp. 13-27
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title = "Thermo-responsive hydrogels based on branched poly(L-lactide)-poly(ethylene glycol) copolymers",
abstract = "Branched poly(L-lactide)-poly(ethylene glycol) (PLLA-PEG) block copolymers were synthesized from trifunctional PLLA and amine functionalized methoxy poly(ethylene glycol)s. The copolymers in water formed hydrogels that showed thermo-responsive behavior. The hydrogels underwent a gel to sol transition with increasing temperature as determined with the vial tilting method and oscillatory rheology. For all copolymers, the transition temperature increased with increasing copolymer concentration. The transition temperature of corresponding branched copolymers also increased with increasing PEG molecular weight, and surprisingly decreased with increasing molecular weight of the PLLA branches. In general, the gel-sol transition is explained by disruption of micellar or aggregate interactions because of partial dehydration and shrinkage of the PEG chains. An increase in the molecular weight of the PLLA branches led to the formation of micelles and aggregates as observed with DLS at low concentrations. It is speculated that the non-uniform size distribution and possible crystallization of longer PLLA blocks may have a negative effect on the formation of micellar packing upon gelation, allowing the disruption of micellar or aggregate interactions to occur at lower temperatures. The transition temperature of the gels could be tuned closely to body temperature by varying the concentration of the solution or the molecular weight of the PEG block and the PLLA blocks, which implies that these polymers may be used as injectable systems for in-situ gel formation.",
keywords = "METIS-254514, IR-69410",
author = "I.W. Velthoen and Tijsma, {Edze J.} and E.J. Tijsma and Dijkstra, {Pieter J.} and Jan Feijen",
note = "Special Issue: (Bio)degradable Polymers from Renewable Resources Issue Edited by Stanislaw Penczek, Stanislaw Slomkowski",
year = "2008",
month = "11",
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doi = "10.1002/masy.200851202",
language = "Undefined",
publisher = "International Union of Pure and Applied Chemistry",
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Velthoen, IW, Tijsma, EJ, Tijsma, EJ, Dijkstra, PJ & Feijen, J 2008, Thermo-responsive hydrogels based on branched poly(L-lactide)-poly(ethylene glycol) copolymers. in S Penczek & S Slomkowski (eds), Selected contributions from the conference: 2nd meeting of the international network (bio)degradable polymers from renewable resources. International Union of Pure and Applied Chemistry, Weinheim, pp. 13-27. https://doi.org/10.1002/masy.200851202

Thermo-responsive hydrogels based on branched poly(L-lactide)-poly(ethylene glycol) copolymers. / Velthoen, I.W.; Tijsma, Edze J.; Tijsma, E.J.; Dijkstra, Pieter J.; Feijen, Jan.

Selected contributions from the conference: 2nd meeting of the international network (bio)degradable polymers from renewable resources. ed. / S. Penczek; S. Slomkowski. Weinheim : International Union of Pure and Applied Chemistry, 2008. p. 13-27.

Research output: Chapter in Book/Report/Conference proceedingConference contributionAcademicpeer-review

TY - GEN

T1 - Thermo-responsive hydrogels based on branched poly(L-lactide)-poly(ethylene glycol) copolymers

AU - Velthoen, I.W.

AU - Tijsma, Edze J.

AU - Tijsma, E.J.

AU - Dijkstra, Pieter J.

AU - Feijen, Jan

N1 - Special Issue: (Bio)degradable Polymers from Renewable Resources Issue Edited by Stanislaw Penczek, Stanislaw Slomkowski

PY - 2008/11/18

Y1 - 2008/11/18

N2 - Branched poly(L-lactide)-poly(ethylene glycol) (PLLA-PEG) block copolymers were synthesized from trifunctional PLLA and amine functionalized methoxy poly(ethylene glycol)s. The copolymers in water formed hydrogels that showed thermo-responsive behavior. The hydrogels underwent a gel to sol transition with increasing temperature as determined with the vial tilting method and oscillatory rheology. For all copolymers, the transition temperature increased with increasing copolymer concentration. The transition temperature of corresponding branched copolymers also increased with increasing PEG molecular weight, and surprisingly decreased with increasing molecular weight of the PLLA branches. In general, the gel-sol transition is explained by disruption of micellar or aggregate interactions because of partial dehydration and shrinkage of the PEG chains. An increase in the molecular weight of the PLLA branches led to the formation of micelles and aggregates as observed with DLS at low concentrations. It is speculated that the non-uniform size distribution and possible crystallization of longer PLLA blocks may have a negative effect on the formation of micellar packing upon gelation, allowing the disruption of micellar or aggregate interactions to occur at lower temperatures. The transition temperature of the gels could be tuned closely to body temperature by varying the concentration of the solution or the molecular weight of the PEG block and the PLLA blocks, which implies that these polymers may be used as injectable systems for in-situ gel formation.

AB - Branched poly(L-lactide)-poly(ethylene glycol) (PLLA-PEG) block copolymers were synthesized from trifunctional PLLA and amine functionalized methoxy poly(ethylene glycol)s. The copolymers in water formed hydrogels that showed thermo-responsive behavior. The hydrogels underwent a gel to sol transition with increasing temperature as determined with the vial tilting method and oscillatory rheology. For all copolymers, the transition temperature increased with increasing copolymer concentration. The transition temperature of corresponding branched copolymers also increased with increasing PEG molecular weight, and surprisingly decreased with increasing molecular weight of the PLLA branches. In general, the gel-sol transition is explained by disruption of micellar or aggregate interactions because of partial dehydration and shrinkage of the PEG chains. An increase in the molecular weight of the PLLA branches led to the formation of micelles and aggregates as observed with DLS at low concentrations. It is speculated that the non-uniform size distribution and possible crystallization of longer PLLA blocks may have a negative effect on the formation of micellar packing upon gelation, allowing the disruption of micellar or aggregate interactions to occur at lower temperatures. The transition temperature of the gels could be tuned closely to body temperature by varying the concentration of the solution or the molecular weight of the PEG block and the PLLA blocks, which implies that these polymers may be used as injectable systems for in-situ gel formation.

KW - METIS-254514

KW - IR-69410

U2 - 10.1002/masy.200851202

DO - 10.1002/masy.200851202

M3 - Conference contribution

SP - 13

EP - 27

BT - Selected contributions from the conference: 2nd meeting of the international network (bio)degradable polymers from renewable resources

A2 - Penczek, S.

A2 - Slomkowski, S.

PB - International Union of Pure and Applied Chemistry

CY - Weinheim

ER -

Velthoen IW, Tijsma EJ, Tijsma EJ, Dijkstra PJ, Feijen J. Thermo-responsive hydrogels based on branched poly(L-lactide)-poly(ethylene glycol) copolymers. In Penczek S, Slomkowski S, editors, Selected contributions from the conference: 2nd meeting of the international network (bio)degradable polymers from renewable resources. Weinheim: International Union of Pure and Applied Chemistry. 2008. p. 13-27 https://doi.org/10.1002/masy.200851202