Effects of bevacizumab loaded PEG-PCL-PEG hydrogel intracameral application on intraocular pressure after glaucoma filtration surgery.

PEG-PCL-PEG (PECE) hydrogel for intracameral injection as a sustained delivery system can get a stable release of the medication and achieve an effective local concentration. The injectable PECE hydrogel is thermosensitive nano-material which is flowing sol at low temperature and can shift to nonflowing gel at body temperature. This study evaluated the intracameral injection of bevacizumab combined with a PECE hydrogel drug release system on postoperative scarring and bleb survival after experimental glaucoma filtration surgery. The best result was achieved in the bevacizumab loaded PECE hydrogels group, which presented the lowest IOP values after surgery. And the blebs were significantly more persistent in this group. Histology, Massion trichrome staining and immunohistochemistry further demonstrated that glaucoma filtration surgery in combination with bevacizumab loaded PECE hydrogel resulted in good bleb survival due to scar formation inhibition. In conclusions, this study demonstrated that bevacizumab-loaded PECE hydrogel for intracameral injection as a sustained delivery system provide a great opportunity to increase the therapeutic efficacy of glaucoma filtration surgery.

The PEG-PCL-PEG Hydrogel as an Implanted Ophthalmic Delivery System after Glaucoma Filtration Surgery; a Pilot Study.

Currently, filtration surgery has been considered as the most effective therapy for glaucoma; however, the scar formation in the surgical area may often lead to failure to the procedure. An implanted drug delivery system may provide localized and sustained release of a drug over an extended period. Poly (ethylene glycol)-poly (ε-caprolactone)-poly (ethylene glycol) (PEG-PCL-PEG, PECE) hydrogel has been successfully synthesized and determined as thermosensitive and biocompatible. In order to overcome the limitations of common local ophthalmic medications, we investigated the function of a self-assembled PECE hydrogel as an intracameral injection-implanted drug carrier to inhibit the formation of postoperative scarring. Following bevacizumal-loaded hydrogel intracameral injection into rabbit eyes, the status of the bleb and filtration fistula formed following the filtering surgery were examined through pathologic evaluation. Due to the sustained release of bevacizumab from the hydrogel, neovascularization and scar formation were inhibited; moreover, there were no corneal abnormalities and other ocular tissue damage found in the rabbits. This suggests that the PECE hydrogel may be considered as the novel biomaterial with potential as a sustained release system in glaucoma filtering surgery. Further studies require in shedding the light on the subject.