Display Settings:

Format

Send to:

Choose Destination
We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Biomaterials. 2009 Oct;30(28):4877-88. doi: 10.1016/j.biomaterials.2009.05.052. Epub 2009 Jun 13.

pH-triggered injectable hydrogels prepared from aqueous N-palmitoyl chitosan: in vitro characteristics and in vivo biocompatibility.

Author information

  • 1Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC.

Abstract

In-situ forming hydrogels triggered by environmental stimuli have emerged as a promising injectable strategy targeted for various biomedical applications. However, several drawbacks associated with temperature-stimulated hydrogels have been reported. Employing a hydrophobically-modified chitosan (N-palmitoyl chitosan, NPCS), we developed a pH-triggered hydrogel system which showed a rapid nanostructure transformation within a narrow pH range (pH 6.5-7.0). NPCS in an aqueous environment was found to be a shear-thinning fluid and exhibited an instant recovery of its elastic properties after shear thinning, thereby making it an injectable material. Additionally, aqueous NPCS, an associating polyelectrolyte, can be rapidly transformed into hydrogel triggered simply by its environmental pH through a proper balance between charge repulsion and hydrophobic interaction. This in-situ hydrogel system was shown to be nontoxic. Subcutaneous injection of aqueous NPCS (pH 6.5) into a rat model resulted in rapid formation of a massive hydrogel at the location of injection. The implanted hydrogel was found to be degradable and was associated with an initial macrophage response which decreased with time as the degradation proceeded. These results suggested that the developed NPCS hydrogel may be used as an injectable drug/cell delivery system.

PMID:
19527916
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk