Cannabidiol-loaded hydrogel contact lenses improved repair of corneal alkali burns in preclinical experiments. Researchers developed a lens that releases CBD and citric acid in response to alkaline conditions, helping neutralize residual chemicals while delivering treatment directly to the injured eye.
The combined lens system reduced inflammatory signals, removed damaging hydroxyl radicals, and inhibited the growth of E. coli and Staphylococcus aureus by more than 90% in laboratory testing. Under alkaline conditions, approximately 59% of its CBD and 52% of its citric acid were released within 24 hours.
In animal experiments, the lenses promoted corneal repair by reducing inflammation and inhibiting unwanted blood-vessel growth. Published in the Journal of Controlled Release, these findings support further development of CBD-containing contact lenses as a targeted treatment approach for chemical injuries to the cornea—the clear front surface of the eye.
“Corneal alkali burn (CAB) poses a significant therapeutic challenge due to alkali infiltration, bacterial infection, inflammation, and angiogenesis, which collectively hinder recovery. The pH microenvironment after CAB is critical for the healing process, but there are few functional biomaterials for this purpose at present.
Herein, we develop a multifunctional hydrogel contact lens (CL) with on-demand release of citric acid (CA) and cannabinoid (CBD), triggered by alkaline conditions, to regulate the microenvironment pH and enhance CAB repair. The CA-functionalized polyvinyl alcohol (PC) and quaternary ammonium chitosan (QCS) are used as hydrogel frameworks, with CBD incorporated as a functional component. The (CBD/QCS/PC, CBD/QPC) hydrogel CL is fabricated using a repeated freeze-thaw process to achieve an interpenetrating network structure.
The findings suggest that the 1CBD/QPC hydrogel CL exhibit superior mechanical properties and biocompatibility (hemolysis rate < 0.6 %, cell viability>90 %). These properties enhance wearing comfort and reducing secondary inflammation. Notably, this hydrogel can release CA (52.23 ± 2.78 %) and CBD (59.24 ± 5.15 %) within 24 h under alkaline conditions to neutralize pH, significantly down-regulate the expression level of inflammatory factors and remove hydroxyl radicals. This mechanism fundamentally addressing the secondary damage of residual lye following CAB. Moreover, the hydrogel CL exhibit potent inhibitory effects on the colonization and growth of both E. coli and S. aureus by destroying bacterial membranes, with an inhibition rate > 90 %.
In vivo results show that hydrogel CL promote the repair of CAB through anti-inflammatory effects and angiogenesis inhibition.
In conclusion, these results demonstrate the potential of this hydrogel CL for treating corneal alkaline burns, providing new insights into treatment of CAB.”
https://pubmed.ncbi.nlm.nih.gov/40383160
“After CAB, the persistent alkaline residue remains a major obstacle to corneal repair. In this study, a novel CBD/QPC hydrogel CL with IPN structure was prepared by blending QCS, PC polymers, and CBD using a repeated freeze-thaw strategy. The findings suggested that the physicochemical properties of the hydrogel CL can be customized by adjusting the concentrations of QCS and CBD.”
https://www.sciencedirect.com/science/article/abs/pii/S0168365925004791?via%3Dihub