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Biocompatibility of genipin and glutaraldehyde cross-linked chitosan materials in the anterior chamber of the eye.

Lai JY - Int J Mol Sci (2012)

Bottom Line: The interleukin-6 expressions at mRNA level were also detected by quantitative real-time reverse transcription polymerase chain reaction.As compared to the non-cross-linked counterparts, the GP-chi samples improved the preservation of corneal endothelial cell density and possessed better anti-inflammatory activities, indicating the benefit action of the GP cross-linker.In summary, the intracameral tissue response to the chemically modified chitosan materials strongly depends on the selection of cross-linking agents.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan 33302, Taiwan; E-Mail: jylai@mail.cgu.edu.tw ; Tel.: +886-3-211-8800 (ext. 3598); ; Biomedical Engineering Research Center, Chang Gung University, Taoyuan 33302, Taiwan ; Molecular Medicine Research Center, Chang Gung University, Taoyuan 33302, Taiwan.

ABSTRACT
Chitosan is a naturally occurring cationic polysaccharide and has attracted much attention in the past decade as an important ophthalmic biomaterial. We recently demonstrated that the genipin (GP) cross-linked chitosan is compatible with human retinal pigment epithelial cells. The present work aims to further investigate the in vivo biocompatibility of GP-treated chitosan (GP-chi group) by adopting the anterior chamber of a rabbit eye model. The glutaraldehyde (GTA) cross-linked samples (GTA-chi group) were used for comparison. The 7-mm-diameter membrane implants made from either non-cross-linked chitosan or chemically modified materials with a cross-linking degree of around 80% were inserted in the ocular anterior chamber for 24 weeks and characterized by slit-lamp and specular microscopic examinations, intraocular pressure measurements, and corneal thickness measurements. The interleukin-6 expressions at mRNA level were also detected by quantitative real-time reverse transcription polymerase chain reaction. Results of clinical observations showed that the overall ocular scores in the GTA-chi groups were relatively high. In contrast, the rabbits bearing GP-chi implants in the anterior chamber of the eye exhibited no signs of ocular inflammation. As compared to the non-cross-linked counterparts, the GP-chi samples improved the preservation of corneal endothelial cell density and possessed better anti-inflammatory activities, indicating the benefit action of the GP cross-linker. In summary, the intracameral tissue response to the chemically modified chitosan materials strongly depends on the selection of cross-linking agents.

No MeSH data available.


Related in: MedlinePlus

Typical specular microscopic images of rabbit corneal endothelium 24 weeks after surgical insertion of various chitosan implants in the ocular anterior chamber. (A) Ctrl (sham-operated); (B) Chi; (C) GTA-chi; and (D) GP-chi groups.
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f3-ijms-13-10970: Typical specular microscopic images of rabbit corneal endothelium 24 weeks after surgical insertion of various chitosan implants in the ocular anterior chamber. (A) Ctrl (sham-operated); (B) Chi; (C) GTA-chi; and (D) GP-chi groups.

Mentions: The morphology of corneal endothelial cells in rabbit eyes was observed by specular microscopy. As shown in Figure 3A, the cells on Descemet’s membrane packed together and exhibited a typical hexagonal shape, indicating that the sham operation does not alter corneal endothelial morphology. After surgical insertion of Chi implants in the ocular anterior chamber, the rabbit corneal endothelium showed some irregular shape of cells (Figure 3B). In the GTA-chi groups, the cellular hexagonality could not be identified (Figure 3C). For the animals bearing the GP cross-linked materials, a single continuous monolayer of cells was present on the posterior surfaces of cornea (Figure 3D). In addition, the individual corneal endothelial cells had distinct borders and possessed similar morphological features to those in the Chi-implanted eyes.


Biocompatibility of genipin and glutaraldehyde cross-linked chitosan materials in the anterior chamber of the eye.

Lai JY - Int J Mol Sci (2012)

Typical specular microscopic images of rabbit corneal endothelium 24 weeks after surgical insertion of various chitosan implants in the ocular anterior chamber. (A) Ctrl (sham-operated); (B) Chi; (C) GTA-chi; and (D) GP-chi groups.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3472724&req=5

f3-ijms-13-10970: Typical specular microscopic images of rabbit corneal endothelium 24 weeks after surgical insertion of various chitosan implants in the ocular anterior chamber. (A) Ctrl (sham-operated); (B) Chi; (C) GTA-chi; and (D) GP-chi groups.
Mentions: The morphology of corneal endothelial cells in rabbit eyes was observed by specular microscopy. As shown in Figure 3A, the cells on Descemet’s membrane packed together and exhibited a typical hexagonal shape, indicating that the sham operation does not alter corneal endothelial morphology. After surgical insertion of Chi implants in the ocular anterior chamber, the rabbit corneal endothelium showed some irregular shape of cells (Figure 3B). In the GTA-chi groups, the cellular hexagonality could not be identified (Figure 3C). For the animals bearing the GP cross-linked materials, a single continuous monolayer of cells was present on the posterior surfaces of cornea (Figure 3D). In addition, the individual corneal endothelial cells had distinct borders and possessed similar morphological features to those in the Chi-implanted eyes.

Bottom Line: The interleukin-6 expressions at mRNA level were also detected by quantitative real-time reverse transcription polymerase chain reaction.As compared to the non-cross-linked counterparts, the GP-chi samples improved the preservation of corneal endothelial cell density and possessed better anti-inflammatory activities, indicating the benefit action of the GP cross-linker.In summary, the intracameral tissue response to the chemically modified chitosan materials strongly depends on the selection of cross-linking agents.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biochemical and Biomedical Engineering, Chang Gung University, Taoyuan 33302, Taiwan; E-Mail: jylai@mail.cgu.edu.tw ; Tel.: +886-3-211-8800 (ext. 3598); ; Biomedical Engineering Research Center, Chang Gung University, Taoyuan 33302, Taiwan ; Molecular Medicine Research Center, Chang Gung University, Taoyuan 33302, Taiwan.

ABSTRACT
Chitosan is a naturally occurring cationic polysaccharide and has attracted much attention in the past decade as an important ophthalmic biomaterial. We recently demonstrated that the genipin (GP) cross-linked chitosan is compatible with human retinal pigment epithelial cells. The present work aims to further investigate the in vivo biocompatibility of GP-treated chitosan (GP-chi group) by adopting the anterior chamber of a rabbit eye model. The glutaraldehyde (GTA) cross-linked samples (GTA-chi group) were used for comparison. The 7-mm-diameter membrane implants made from either non-cross-linked chitosan or chemically modified materials with a cross-linking degree of around 80% were inserted in the ocular anterior chamber for 24 weeks and characterized by slit-lamp and specular microscopic examinations, intraocular pressure measurements, and corneal thickness measurements. The interleukin-6 expressions at mRNA level were also detected by quantitative real-time reverse transcription polymerase chain reaction. Results of clinical observations showed that the overall ocular scores in the GTA-chi groups were relatively high. In contrast, the rabbits bearing GP-chi implants in the anterior chamber of the eye exhibited no signs of ocular inflammation. As compared to the non-cross-linked counterparts, the GP-chi samples improved the preservation of corneal endothelial cell density and possessed better anti-inflammatory activities, indicating the benefit action of the GP cross-linker. In summary, the intracameral tissue response to the chemically modified chitosan materials strongly depends on the selection of cross-linking agents.

No MeSH data available.


Related in: MedlinePlus