The complex anatomy of the eye presents a major challenge in the treatment of posterior segment eye diseases, hindering the effective delivery of medications. Conventional treatments, including topical eye drops and intravitreal injections, are limited by poor bioavailability and short residence time, necessitating frequent dosing to manage the disease. Intravitreal injections can also lead to serious ocular complications. Biodegradable nano-based drug delivery systems (DDSs) have emerged as a potential solution to these limitations, offering longer residence time in ocular tissues and better penetration through ocular barriers. Furthermore, the biodegradable polymers used to create these systems are nanosized, reducing the risk of toxicity and adverse reactions.
This review provides a comprehensive overview of the latest advances in biodegradable nano-based DDSs for treating posterior segment diseases. By examining current therapeutic challenges and exploring various types of biodegradable nanocarriers, we aim to highlight the potential of these systems to enhance treatment outcomes. Our review includes pre-clinical and clinical studies published between 2017 and 2022, demonstrating the rapid evolution of nano-based DDSs. As biodegradable materials continue to advance, and our understanding of ocular pharmacology improves, nano-based DDSs hold great promise for overcoming obstacles encountered in clinical practice.