Injectable Schiff base polysaccharide hydrogels for intraocular drug loading and release

Area of Science:

• Biomaterials Science
• Ophthalmology
• Drug Delivery

Background:

• Fungal endophthalmitis requires effective intraocular drug delivery.
• Voriconazole (VCZ) is a clinically effective antifungal agent but faces challenges in intraocular administration.
• Injectable hydrogels offer potential for sustained drug release in the eye.

Purpose of the Study:

• To develop and characterize a novel in situ injectable hydrogel for intraocular delivery of voriconazole (VCZ).
• To investigate the drug loading and controlled release properties of the hydrogel system.
• To evaluate the potential of this system for treating fungal endophthalmitis.

Main Methods:

• Synthesized an injectable hydrogel via Schiff base reaction between polyaldehyde dextran (PAD) and carboxymethyl chitosan (CMCTS).
• Loaded water-insoluble VCZ using β-cyclodextrin (β-CD) inclusion complexes within the hydrogel matrix.
• Investigated hydrogel properties (gelation, degradation, drug release) using varying PAD:CMCTS ratios in phosphate-buffered saline (PBS).

Main Results:

• Successfully synthesized an in situ injectable hydrogel capable of loading VCZ.
• Demonstrated that hydrogel properties, including drug release, can be tuned by adjusting cross-linking density and β-CD concentration.
• Proposed a multistage drug-controlled release mechanism based on hydrogel characteristics.

Conclusions:

• The developed VCZ-loaded injectable hydrogel is a promising strategy for intraocular drug delivery.
• This system offers a potential new treatment for fungal endophthalmitis via sustained drug release in the vitreous cavity.
• The tunable properties of the hydrogel allow for customization to meet specific treatment requirements.