Purchase this article with an account.
Zengping Liu, Xinyi Su, Mein Jin Tan, Zibiao Li, Rajamani Lakshminarayanan, Veluchamy A Barathi, Xian Jun Loh, Gopal Lingam; Engineering an injectable thermosensitive hydrogel as an internal tamponading agent for vitreo-retinal surgery. Invest. Ophthalmol. Vis. Sci. 2016;57(12):5819.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
An optimal intraocular tamponade is crucial for vitreo-retinal surgery. We developed a biodegradable thermogelling copolymer, thereafter, investigated its cytotoxicity on ARPE-19 cell culture and intraocular biocompatibility in vitrectomised eyes of rabbits.
Optimized multiblock poly(ether urethane)s comprising poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPG) blocks were synthesized. Surface tension was tested on ultrathin plastic film with various punched holes at 37C. Cytotoxicity studies were conducted in series dilutions (1:1 to 1:20) of the hydrogels on confluent ARPE-19 cell culture after 24h exposure by MTT assay. Vitrectomy was performed on 3 eyes of NZW rabbits followed by 5% (wt%) poly(PEG/PPG) injection, while the fellow eyes as controls. Intraocular pressure was measured and slit lamp examination was recorded. In addition, repetitive in-vivo images by SD-OCT and fundus photography were obtained after at Day 1, 3, 7, 14, 28 and 56 post operation.
Poly(PEG/PPG urethane)s aqueous solutions required a minimum concentration of 5% (wt%) to undergo a reversible sol-gel transition at 37C. Polymer hydrogels can remain above the plastic film with up to Φ 3 mm punched hole. The avereage cell viability related to different concentrations of hydrogel solutions was 92.1±16.6% without concentration related effect . Poly(PEG/PPG) solution (5%, 0.5 ml to 1 ml) is easily injected into vitrectomised eye via 23G needle at room temperature and gelates within 3-5 minutes in vivo. Post-operatively, intraocular pressure of operated eyes maintained between 8.4 to 19.8 mmHg. Conjunctiva and anterior chamber were fully recovered without any obvious contamination in all three rabbits. Vacuolation at the posterior capsule was observed in 2 out of 3 rabbits with hydrogel injection since Day 3. Color fundus and SD-OCT images demonstrated retinal attachment.
Thermosensitive hydrogels demonstrated cell compatibility in vitro. They were injectable and easily achieved sol-gel transition with superior surface tension during vitrectomy surgery. Long term follow up of biocompatibility studies in vivo are still ongoing. These studies indicate a potential use for thermosensitive hydrogels as an intraocular tamponade.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.
This PDF is available to Subscribers Only