Advanced Thermogel Biomaterials for Ophthalmic Applications and Drug Delivery

Retinal detachment is amongst the leading causes of blindness globally. After vitrectomy surgery, vitreous endotamponades are implanted into the vitreous cavity to facilitate retinal reattachment and recovery. Existing endotamponade materials are suboptimal: silicone oil can lead to inflammation and require follow-up surgery for removal, while expansile gases such as sulfur hexafluoride results in raised intra-ocular pressure and require the patient to adopt prolonged face-down positioning due to their buoyancy. Recently, temperature-responsive hydrogels, also known as thermogels, have emerged as a new highly-promising class of vitreous endotamponades. Our self-assembled thermogels offer easy injectability, transparency, possess the same density and refractive indices as native vitreous humor, show low in-vivo cytotoxicity and have the ability to provide sufficient swelling counter-force to facilitate retina re-attachment. In this presentation, our team’s efforts in developing new generations of biocompatible thermogel-based vitreous endo-tamponades will be discussed. We show that our thermogels can be naturally cleared from the vitreous cavity post-surgery, whilst allowing the regeneration of a vitreous-like body with high proteomic similarity as native vitreous – the first biomaterial known to do so. In addition, we show the profound influences of polymer branching on the in-vivo performance of thermogel endotamponades, and also demonstrate the importance of this often-overlooked parameter on applications such as sustained drug release. Our findings demonstrate the vast potential of self-assembled thermogels as a viable biomaterial that can revolutionise ophthalmic treatment.