RESUMO
Objective To screen a kind of polyvinyl alcohol (PVA) hydrogel with similar physical properties to human vitreous body as to provide basis for exploring new vitreous substitutes.Methods Different concentrations (1％,3％,7％) PVA solution were crosslinked by γ-irradiation (Co60),and 1％,3％ and 7％ PVA hydrogels were harvested.Then PVA hydrogels with similar properties to natural vitreous were screened by detecting the physical and optical properties (density,water content,light transmittance,refractive index,pH value,swelling property) and rheological properties and cytotoxicity of PVA hydrogels.Results As for the physical and optical properties of the hydrogels,the water content,refractive index,light transmittance,pH value and density of 1％,3％ and 7％ PVA hydrogel was 98.90％ vs.98.10％ vs.93.50％,1.335 5 vs.1.336 1 vs.1.342 5,94.80％ vs.93.20％ vs.88.20％,7.22 vs.7.25 vs.7.41 and 1003.9 g · L-1d vs.1014.4 g · L-1 vs.1114.7 g · L-1,respectively.Finally,1％ and 3％PVA hydrogels had the similar physical and optical properties to the human vitreous.As for rheological properties,the storage modulus (G') of the three PVA hydrogels was larger than the loss modulus (G"),indicating that these three hydrogels were viscoelastic gel,and the elastic properties was greater than the viscosity.1％ PVA:G'was (3.2 ±1.1)Pa,G" was (0.8 ±0.5)Pa;3％ PVA:G'was (6.1 ± 1.3)Pa,G" was (1.3 ±0.9)Pa;7％ PVA:G'was (106.5 ± 18.6) Pa and G" was (18.3 ± 12.8) Pa.According to resilience,the hydrogels can be ranked as follows:7％ PVA ＞ 3％ PVA ＞ 1％ PVA;in terms of creep,3％ PVA ＞ 7％ PVA ＞ 1％ PVA.Additionally,MTT colorimetric assay showed that there was no significant difference in A values among the three groups by cells culture in 1％,3％ and 7％ PVA for 72 hours (all P ＞0.05),suggesting that all the three hydrogels showed no obvious cytotoxicity and had good biocompatibility.Conelusion 3％ PVA hydrogel has similar optical,physical and rheological properties to the human vitreous,and shows good biocompatibility,which can be one of vitreous substitutes.