Publication detail

Thermogelling properties of injectable functionalized hydrogels

VOJTOVÁ, L. MICHLOVSKÁ, L. CHAMRADOVÁ, I. JANČÁŘ, J.

Original Title

Thermogelling properties of injectable functionalized hydrogels

English Title

Thermogelling properties of injectable functionalized hydrogels

Type

abstract

Language

en

Original Abstract

Proposed work deals with preparation, characterization and rheological study of well-defined smart injectable hydrogels from biodegradable, biocompatible, controlled life-time copolymers based on hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly([(lactic acid)-co-(glycolic acid)] (PLA/PGA) copolymer. Thermosensitive PLGA-PEG-PLGA copolymer with PLGA/PEG weight ratio of 1.5; 2; 2.5; 3.0 and LA/GA molar ratio equal to 2.4; 3.0 and 3.4 were prepared and additionally functionalized by itaconic anhydride (ITA) bringing both reactive carbon double bonds and functional -COOH groups to polymer both ends. Aqueous solutions of both modified and unmodified copolymers are able to form free flowing sol at room temperature and clear gel at temperature around 37 deg.C. Therefore, sol-gel transitions, thermogelling and viscoelastic properties were investigated using both test tube inverting method (TTIM) and rheometer. Combined methods give comprehensive information about changing in color, viscosity, elastic and loss modulus determining whether or not the material is appropriate as an injectable biomedical hydrogel. No matter if copolymer was modified or not, it was found that the critical gel temperature increased with decreasing th PLGA/PEG weight ratio and the critical gel concentration grew up with decreasing molar ratio of LA/GA. The gel stiffness increased with the polymer concentration moving the gel point of copolymer to the lower temperature. However, in all cases the ITA functionalization improved both the gel stiffness and sol-gel characteristics of original PLGA-PEG-PLGA copolymer by approaching gel phase to body temperature required for injectable drug carriers, bone adhesives or temporary implants in regenerative medicine.

English abstract

Proposed work deals with preparation, characterization and rheological study of well-defined smart injectable hydrogels from biodegradable, biocompatible, controlled life-time copolymers based on hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly([(lactic acid)-co-(glycolic acid)] (PLA/PGA) copolymer. Thermosensitive PLGA-PEG-PLGA copolymer with PLGA/PEG weight ratio of 1.5; 2; 2.5; 3.0 and LA/GA molar ratio equal to 2.4; 3.0 and 3.4 were prepared and additionally functionalized by itaconic anhydride (ITA) bringing both reactive carbon double bonds and functional -COOH groups to polymer both ends. Aqueous solutions of both modified and unmodified copolymers are able to form free flowing sol at room temperature and clear gel at temperature around 37 deg.C. Therefore, sol-gel transitions, thermogelling and viscoelastic properties were investigated using both test tube inverting method (TTIM) and rheometer. Combined methods give comprehensive information about changing in color, viscosity, elastic and loss modulus determining whether or not the material is appropriate as an injectable biomedical hydrogel. No matter if copolymer was modified or not, it was found that the critical gel temperature increased with decreasing th PLGA/PEG weight ratio and the critical gel concentration grew up with decreasing molar ratio of LA/GA. The gel stiffness increased with the polymer concentration moving the gel point of copolymer to the lower temperature. However, in all cases the ITA functionalization improved both the gel stiffness and sol-gel characteristics of original PLGA-PEG-PLGA copolymer by approaching gel phase to body temperature required for injectable drug carriers, bone adhesives or temporary implants in regenerative medicine.

Keywords

injectable hydrogels, sol-gel transition, rheology, viscoelastic properties

Released

01.06.2012

Publisher

Institute of Macromolecular Chemistry Academy of Sciences of the Czech Republic

Location

Praha

ISBN

978-80-85009-72-9

Book

76th Prague Meeting on Macromolecules, Polymer in Medicine

Pages from

121

Pages to

121

Pages count

1

BibTex


@misc{BUT97598,
  author="Lucy {Vojtová} and Lenka {Michlovská} and Ivana {Chamradová} and Josef {Jančář}",
  title="Thermogelling properties of injectable functionalized hydrogels",
  annote="Proposed work deals with preparation, characterization and rheological study of well-defined smart injectable hydrogels from biodegradable, biocompatible, controlled life-time copolymers based on hydrophilic poly(ethylene glycol) (PEG) and hydrophobic poly([(lactic acid)-co-(glycolic acid)] (PLA/PGA) copolymer. Thermosensitive PLGA-PEG-PLGA copolymer with PLGA/PEG weight ratio of 1.5; 2; 2.5; 3.0 and LA/GA molar ratio equal to 2.4; 3.0 and 3.4 were prepared and additionally functionalized by itaconic anhydride (ITA) bringing both reactive carbon double bonds and functional -COOH groups to polymer both ends. Aqueous solutions of both modified and unmodified copolymers are able to form free flowing sol at room temperature and clear gel at temperature around 37 deg.C. Therefore, sol-gel transitions, thermogelling and viscoelastic properties were investigated using both test tube inverting method (TTIM) and rheometer. Combined methods give comprehensive information about changing in color, viscosity, elastic and loss modulus determining whether or not the material is appropriate as an injectable biomedical hydrogel. No matter if copolymer was modified or not, it was found that the critical gel temperature increased with decreasing th PLGA/PEG weight ratio and the critical gel concentration grew up with decreasing molar ratio of LA/GA. The gel stiffness increased with the polymer concentration moving the gel point of copolymer to the lower temperature. However, in all cases the ITA functionalization improved both the gel stiffness and sol-gel characteristics of original PLGA-PEG-PLGA copolymer by approaching gel phase to body temperature required for injectable drug carriers, bone adhesives or temporary implants in regenerative medicine.",
  address="Institute of Macromolecular Chemistry Academy of Sciences of the Czech Republic",
  booktitle="76th Prague Meeting on Macromolecules, Polymer in Medicine",
  chapter="97598",
  institution="Institute of Macromolecular Chemistry Academy of Sciences of the Czech Republic",
  year="2012",
  month="june",
  pages="121--121",
  publisher="Institute of Macromolecular Chemistry Academy of Sciences of the Czech Republic",
  type="abstract"
}