Abstract
Purpose:
To evaluate the IOP-lowering effect of hydrogel sustained-release of C3 exoenzyme in rat eyes.
Methods:
C3 exoenzyme was expressed in E.coli and purified by affinity chromatography. Immunofluorescence was performed in NIH 3T3 cells treated with C3 to verify the cellular uptake of the protein. A sustained-release formulation was prepared comprising a bio-absorbable polymer hydrogel and C3 transferase. IOP of Sprague-Dawley rats was measured with the TonoLab rebound tonometer. Baseline IOP was obtained before an intracameral injection of 6 µl hydrogel (30%) into both eyes to induce an acute ocular hypertension. IOP was measured at 2, 14 and 24 h post-injection. After 24 h, 6 µl of the sustained-release formulation (30% hydrogel containing 15 µg C3 exoenzyme) was injected into the anterior chamber of the right eyes, while 6 µl hydrogel (30%) was injected into the anterior chamber of left eyes as control. IOP was measured at 2 h and then every 12 h following the second intracameral injection.
Results:
Intracameral injection of hydrogel raised rat IOP to 35~47 mmHg. The sustained-release of C3 exoenzyme significantly lowered IOP. Its maximal IOP reduction effect was 41% (17.2 ± 2.2 mmHg) at 26 h after the second injection (p < 0.05). The IOP-lowering effect of C3 exoenzyme lasted about 60 h.
Conclusions:
Hydrogel sustained-release of C3 exoenzyme can reduce IOP in a rat model with ocular hypertension.