Drug Discovery, Delivery and Patient Care (DDDPC) Research Theme, Kingston University London, School of Life Sciences, Pharmacy and Chemistry, Kingston Upon Thames KT1 2EE, UK.
Drug Delivery Research Group, School of Science, Auckland University of Technology, Auckland, New Zealand.
Adv Drug Deliv Rev. 2018 Feb 15;126:113-126. doi: 10.1016/j.addr.2017.12.017. Epub 2017 Dec 27.
Aqueous gels formulated using hydrophilic polymers (hydrogels) along with those based on stimuli responsive polymers (in situ gelling or gel forming systems) continue to attract increasing interest for various eye health-related applications. They allow the incorporation of a variety of ophthalmic pharmaceuticals to achieve therapeutic levels of drugs and bioactives at target ocular sites. The integration of sophisticated drug delivery technologies such as nanotechnology-based ones with intelligent and environment responsive systems can extend current treatment duration to provide more clinically relevant time courses (weeks and months instead of hours and days) which will inevitably reduce dose frequency, increase patient compliance and improve clinical outcomes. Novel applications and design of contact lenses and intracanalicular delivery devices along with the move towards integrating gels into various drug delivery devices like intraocular pumps, injections and implants has the potential to reduce comorbidities caused by glaucoma, corneal keratopathy, cataract, diabetic retinopathies and age-related macular degeneration. This review describes ophthalmic gelling systems with emphasis on mechanism of gel formation and application in ophthalmology. It provides a critical appraisal of the techniques and methods used in the characterization of ophthalmic preformed gels and in situ gelling systems along with a thorough insight into the safety and biocompatibility of these systems. Newly developed ophthalmic gels, hydrogels, preformed gels and in situ gelling systems including the latest in the area of stimuli responsive gels, molecularly imprinted gels, nanogels, 3D printed hydrogels; 3D printed devices comprising ophthalmic gels are covered. Finally, new applications of gels in the production of artificial corneas, corneal wound healing and hydrogel contact lenses are described.
水凝胶是由亲水性聚合物（水凝胶）和响应性聚合物（原位凝胶或凝胶形成系统）组成的，它们在各种与眼部健康相关的应用中继续引起越来越多的关注。它们允许各种眼科药物的掺入，以在靶眼部达到药物和生物活性的治疗水平。将基于纳米技术的复杂药物输送技术与智能和环境响应系统相结合，可以延长当前的治疗持续时间，提供更具临床相关性的时间过程（数周和数月而不是数小时和数天），这将不可避免地减少剂量频率，提高患者依从性并改善临床结果。新型接触镜和管腔内给药装置的应用和设计，以及将凝胶整合到各种药物输送装置（如眼内泵、注射剂和植入物）中，有可能减少青光眼、角膜病、白内障、糖尿病性视网膜病变和年龄相关性黄斑变性等疾病引起的合并症。本综述描述了眼科凝胶系统，重点介绍了凝胶形成的机制及其在眼科中的应用。它对用于表征眼科预成型凝胶和原位凝胶系统的技术和方法进行了批判性评估，并深入了解了这些系统的安全性和生物相容性。新开发的眼科凝胶、水凝胶、预成型凝胶和原位凝胶系统，包括刺激响应凝胶、分子印迹凝胶、纳米凝胶、3D 打印水凝胶等领域的最新进展，涵盖了眼科凝胶的 3D 打印设备。最后，还描述了凝胶在人工角膜生产、角膜愈合和水凝胶隐形眼镜中的新应用。
