Ocular drug delivery system and uses thereof

An ocular drug delivery system, comprising:

• a positively charged chitosan-modified hydrogel which is obtained by a process including subjecting a hydrogel to a click chemistry reaction with a chitosan;
• a secretory phospholipase A2 (sPLA2) hydrolysable liposome encapsulating an anti-inflammatory drug and having a negative surface charge;
• a first thiolated hyaluronic acid (HA-SH) nanoparticle encapsulating a wound-healing drug and having a negative surface charge;
• and
• a second HA-SH nanoparticle encapsulating a transforming growth factor-β (TGF-β) inhibitor and having a negative surface charge, the second HA-SH nanoparticle having a crosslinking index higher than that of the first HA-SH nanoparticle;
• wherein the sPLA2 hydrolysable liposome, the first HA-SH nanoparticle, and the second HA-SH nanoparticle are attached to the positively charged chitosan-modified hydrogel by electrostatic attraction.