Record Details

In vitro evaluation of in situ gels as short term vitreous substitutes

DSpace at IIT Bombay

View Archive Info
 
 
Field Value
 
Title In vitro evaluation of in situ gels as short term vitreous substitutes
 
Creator SURI, S
BANERJEE, R
 
Subject rheological properties
intraocular-pressure
pseudomonas-elodea
delivery-systems
hyaluronic-acid
gellan gum
silicone
biocompatibility
biodegradation
implants
gellan
in situ gel
ocular biomaterial
vitreous
 
Description Dysfunction of the vitreous humor, present in the posterior cavity of the eye, leads to its detachment from the retina and vision loss. In this study, biopolymers were evaluated as in situ gels for short term vitreous substitution. Biophysical characterization revealed that the viscosity of the vitreous was > 4000 cP at a shear rate of 0.15/s and it formed a gel with elastic modulus G' greater than the viscous modulus G". Biopolymers of gellan and hyaluronic acid (8:2 w/w, 1% concentration) were low viscosity liquids at 37 degrees C and gelation was triggered both by the addition of 0.18 mM CaCl2 as well as. ocular temperature, thus making them feasible as in situ gels. Gelation was confirmed by viscoelastic moduli where G' was greater than G", similar to the vitreous and unlike that of silicone oil, a common vitreous substitute. The gels had a viscosity > 5000 cP at a shear rate of 0.512/s, excellent light transmittance and absence of syneresis. Contact angle studies with water and simulated ocular fluids showed that gellan hyaluromc acid gels had similar wetting properties to that of vitreous with contact angles of 27 degrees +/- 1 degrees, 36.7 degrees +/- 1.6 degrees, and 33.7 degrees +/- 0.5 degrees for water, simulated tear fluid, and simulated aqueous humor, respectively. The results of this study suggest that biopolymers of gellan and hylauronic acid are suitable as in situ gels, have biophysical properties similar to that of the vitreous, and may be promising as alternatives to silicone oil as short-term vitreous substitutes. (c) 2006 .
 
Publisher WILEY-LISS
 
Date 2011-09-01T13:25:21Z
2011-12-26T12:59:40Z
2011-12-27T05:52:17Z
2011-09-01T13:25:21Z
2011-12-26T12:59:40Z
2011-12-27T05:52:17Z
2006
 
Type Article
 
Identifier JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A, 79A(3), 650-664
1549-3296
http://dx.doi.org/10.1002/jbm.a.30917
http://dspace.library.iitb.ac.in/xmlui/handle/10054/12790
http://hdl.handle.net/10054/12790
 
Language en