Interaction of Hypericin Embedded in Liposomes with the ocular tissue of new Zealand rabbits for application in photodynamic therapy

The potent photodynamic properties of hypericin [HY] elicit a range of light-dependant virucidal and tumoricidal activities. This work highlights the interaction of liposomes loaded with HY with the aqueous humor and crystalline lens of the rabbits' eye in comparison with those treated with HY only. Six group of New Zealand rabbits of six rabbits each were used in this study. The rabbits received 30 micro l of HY or liposomes loaded with hypericin topically once a day for one week as an eye drop of HY concentration 1-9 micro M. The eyes of rabbits were exposed to He-Ne laser for 5 min after 30 min from administration of HY or liposomes loaded with HY for the studied groups. Total soluble protein, molecular weight distribution, electrophoretic mobility and refractive index for both aqueous humor and soluble lens crystallins were investigated for the studied samples. The obtained results showed an increase in the solubility of lens protein and aqueous humor, an increase in the molecular weights of beta and gamma proteins accompanied by fluctuations in he electrophoretic mobility and slight decrease in the refractive index at high concentration of HY. The changes were higher in the samples treated with HY more than those treated with liposomes loaded with HY. It is concluded from the obtained data that hypericin embedded in liposomes may be used as a hotosensitizer for photodynamic therapy at low fractionated doses with minimal side effects

Characterization of tear film protein in rabbits following exposure to SR90 B-radiation

Purpose To assess the changes in tear composition in rabbits following exposure to Sr90 beta - radiation. Methods The damage induced by beta - radiation from Sr90 applicator, at doses of 20 Gy, 40 Gy and 60 Gy in weekly sitting of 10 Gy to treated left eye and the right untreated one of 25 there-month-old New Zealand white rabbits was assessed. An additional ten rabbits were used as a control. Tears collected after 24 hours were measured for protein content and lysozyme concentration. The lysozyme molecular structure was studied through the use of column chromatography; cellogel paper electrophoresis and radial diffusion technique was utilized for the demonstrated doses. The delayed effects of beta-radiation on tear lysozyme after one and three months' post exposure was also studied. All samples were analyzed six times and the mean result obtained. Results The radiation damage process increased by increasing the exposure doses and this phenomenon still propagated after the study delay periods which reported no remarks for repair. A significant decrease in the lysozyme concentration for the treated and untreated eyes was observed after the dose of 60 Gy [-61.46%] for the treated eye and [-70.64%] for the untreated one. Conclusions Although irradiation has proved to be a valuable tool in controlling eye disease, with excellent survival rates, nevertheless, side effects of radiation form serious limitations for the applicabilities of this technique

Chromatographic studies on experimental candida keratitis

Chromatographic analysis and soluble protein contents of aqueous humour and crystalline lens were done in induced ocular infection of rabbit's eyes by Candida albicans in both treated and non-treated inflamed eyes as well as their normal controls. The results showed a significant decrease in the soluble protein contents and molecular weights in aqueous humour and crystalline lens of non-treated eyes. The topical treatment showed an important response which made the treated eyes to be slightly affected by the Candida albicans infections. We conclude from this study that early treatment prevents severe ocular complications and column chromatography is a sensitive technique for protein analysis of crystalline lens and aqueous humour

Comparative study of the biophysical changes in senile, complicated and congenital cataracts

Refractive index, electrophoretic mobility and protein content of the soluble lens proteins were studied in senile, complicated, and congenital cataracts. In senile cataract, the refractive index and protein content showed remarkable decrease accompanied with significant increase in the electrophoretic mobility. Obtained results of complicated cataract demonstrated marked fluctuations as compared with the healthy controls. Refractive index and the soluble protein content in congenital cataract showed general decrease while the electrophoretic mobility revealed slight increase