Purchase this article with an account.
P. Lu, J. Lai, K. Chen, G. Hsiue, W. Hsu; A Novel Methodology for Functional Assessment and Tissue Response of Biomaterials in the Immune-privileged Site: The "Anterior Chamber of Rabbit Eyes" Model . Invest. Ophthalmol. Vis. Sci. 2003;44(13):3770.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: The eye has long been considered an immune-privileged site, along with the brain, gravid uterus and testis. To develop a novel method for investigating the interactions between implanted biomaterials and an immune-privileged site. Methods: A 7mm gelatin (IEP = 5.0, MW = 100,000) disc with a thickness of 700-800 µm was prepared by solution-casting methods and sterilized with γ-ray irradiation. It was implanted into the anterior chamber of right eye of a 3-3.5 kg New Zealand adult albino rabbit while the left eye served as a control. The parameters of tissue reactions to gelatin included the morphology of anterior segment of rabbit's eye such as the clarity of cornea, grades of cells and flare of aqueous humor, observed by slit lamp microscopy; intraocular pressure (IOP) measured by pneumo-tonometer; corneal thickness determined by ultrasonic pachymeter; pH and osmolality of aqueous humor learned by pH indicator strips and osmometer respectively. Histopathological sections were examined after sacrificing rabbits. These parameters were evaluated at different postoperative time points: 1, 2, 3, 4, 7, 8, 9, 14, 16, 18, 21, 42, 49 and 70 days. To quantitate the biological properties of a specific biomaterial, gelatin, administrated in anterior chamber of eyes, a defined grading system was constructed via scoring the parameters described above. The statistical analysis was conducted with Student's t-test. Results: After implantation, by slit lamp microscope, the gelatin disc showed the irregular colloidal aggregates gradually during the process of degradation. There were no reactive cells and flare noted in the aqueous humor. IOP was lower than control for about 5 mmHg (p<0.05) in the first post-operative 3 weeks and returned to the normal scope, 10~15 mmHg. The corneal thickness increased to a level about 800µm in post-operatively 1 week then was restored to about 400 µm. The pH and osmolality of aqueous humor did not go beyond the range of 7 to 7.4 and 346 mOsm respectively through the end of this experiment. No inflammation and immune rejection was demonstrated from the histopathological examination of ocular tissue sections. Conclusions: We have shown gelatin is an inert biomaterial with little tissue reactions in an immune-privileged site by a novel testing method, the "anterior chamber of rabbit eyes model". It is an efficient method for investigating the biological properties of a biomaterial applied in an immune-privileged site.
This PDF is available to Subscribers Only