Hyaluronic acid-based hydrogels for suprachoroidal administration in glaucoma treatment: influence of precursor characteristics on hydrogel properties

Introduction: Glaucoma is a leading cause of vision loss that is associated with an increase in intraocular pressure. The injection of a hydrogel into the suprachoroidal space (SCS) is a promising treatment, decreasing intraocular pressure and allowing drug delivery.

Methods: We developed hydrogels based on hyaluronic acid (HA) and poly(ethylene glycol) (PEG) for the potential delivery of hydrophobic drugs in the SCS. First, HA was modified with thiol groups and then crosslinked with PEG acrylates via Michael addition, inducing gelation. To mimic physiological conditions, a PBS buffer was used as the solvent. Curcumin was encapsulated as a model hydrophobic drug. Westudied the influence of varying the modification degree of HA and PEG chain length on the final properties of the hydrogel.

Results: We obtained cohesive hydrogels with fast in situ gelation times, approximately two minutes, that are tough and able to withstand high shear strains. The gels have a distinctive intense color due to the dispersion of curcumin in the polymer matrix. In vitro tests revealed that hydrogels release the encapsulated curcumin over time, losing their color.

Conclusion: Weobtained hydrogels with interesting properties, compatible withinjection into the SCS. These materials are very promising and will continue to be studied for this application.