Jump to main content
Jump to site search


Thiolated γ-polyglutamic acid as a bioadhesive hydrogel-forming material: evaluation of gelation, bioadhesive properties and sustained release of KGF in the repair of injured corneas

Author affiliations

Abstract

Keratinocyte growth factor (KGF) has a good therapeutic effect on injured corneas. However, due to the washout of tears and blinking, locally administrated KGF usually has a short residence time on the surface of an injured cornea, resulting in its poor bioavailability. Herein, a bioadhesive hydrogel is described produced using cysteine-modified γ-polyglutamic acid (PGA-Cys) as the hydrogel-forming material to locally deliver KGF. A series of PGA-Cys polymers with different graft ratios of cysteine were firstly synthesized and carefully characterized. Thereafter, the PGA-Cys hydrogel was screened by changing the graft ratio of cysteine and polymer concentration, and the apparent viscosities and bioadhesive force were also carefully investigated. It was found that PGA-Cys polymers with different graft ratios of cysteine exhibited tunable apparent viscosity and bioadhesive properties at the same polymer concentration. When PGA-Cys with a graft ratio of 1.5 mmol g−1 of cysteine (PGA-Cys-1.5) was used as hydrogel-forming material, the hydrogel exhibited a good gelation property with an apparent viscosity of 5.2 Pa s and strong bioadhesive force of 167 ± 0.5 mN. In vitro release study showed that KGF was slowly released from PGA-Cys-1.5 hydrogel over a longer time in comparison to PGA solution alone. Moreover, PGA-Cys-1.5 hydrogel enabled most of the encapsulated KGF to be retained on the cornea and conjunctiva after local administration. Meanwhile, the morphology of the corneal epithelium in the alkali-injured cornea of mice was well repaired after 7 days of treatment with KGF-PGA-Cys-1.5 hydrogel. The therapeutic mechanism was strongly associated with inhibiting corneal inflammation and neovascularization, promoting proliferation of the corneal epithelium and inhibiting apoptosis. Overall, the use of the bioadhesive PGA-Cys hydrogel with a suitable KGF release profile may be a more promising approach than using PGA solution alone and KGF to repair injured corneas.

Graphical abstract: Thiolated γ-polyglutamic acid as a bioadhesive hydrogel-forming material: evaluation of gelation, bioadhesive properties and sustained release of KGF in the repair of injured corneas

Back to tab navigation

Supplementary files

Publication details

The article was received on 03 Mar 2019, accepted on 25 Mar 2019 and first published on 25 Mar 2019


Article type: Paper
DOI: 10.1039/C9BM00341J
Citation: Biomater. Sci., 2019, Advance Article

  •   Request permissions

    Thiolated γ-polyglutamic acid as a bioadhesive hydrogel-forming material: evaluation of gelation, bioadhesive properties and sustained release of KGF in the repair of injured corneas

    H. Xu, M. Tong, L. Wang, R. Chen, X. Li, Y. Sohawon, Q. Yao, J. Xiao and Y. Zhao, Biomater. Sci., 2019, Advance Article , DOI: 10.1039/C9BM00341J

Search articles by author

Spotlight

Advertisements