Aptamer-Based Delivery Systems for VEGF and NGF Modulation in Ocular Therapies

Many diseases that threaten vision originate from imbalances in the production or signaling of vascular endothelial growth factor (VEGF) and nerve growth factor (NGF). While VEGF inhibitors can suppress pathological blood vessel growth and NGF therapies can promote tissue regeneration, treatments employing the growth factors are often invasive, inefficient, or not suitable for long-term use. For example, the use of NGF-containing eye drops requires high drug loads and frequent administration, thereby increasing the potential for side effects and high costs. Based on a critical overview of currently used experimental and clinical approaches for the delivery or inhibition of growth factors, we highlight aptamers as promising yet underexplored therapeutic tools. Aptamers combine high target specificity, tunable structure and affinity, stability, low immunogenicity, and scalable chemical synthesis. These properties allow aptamers to be readily incorporated into biomaterial carriers, such as hydrogels, implants, or contact lenses, to improve the controlled binding of growth factors for precise modulation of their levels in ocular tissues via release or sequestration strategies. Leveraging these advantages in future developments could facilitate the aptamer-functionalized platforms to overcome the limitations of current therapies and advance more sustainable, targeted, and patient-oriented treatment strategies in ophthalmology.