Rheological and physicochemical optimization of hydrogels as potential vitreous body substitutes for in vitro release...

Area of Science:

• Ophthalmology
• Biomaterials Science
• Rheology

Background:

• Aging populations face increased age-related posterior eye diseases.
• Accurate in vitro models are needed for preclinical drug development.
• The vitreous body is a key component requiring simulation in ocular drug testing.

Purpose of the Study:

• To investigate and compare rheological properties of various hydrogels as vitreous body substitutes.
• To identify optimized hydrogel formulations for in vitro vitreous modeling.
• To assess the suitability of hydrogels for simulating drug release and distribution.

Main Methods:

• Systematic rheological characterization (viscosity, loss factor, frequency sweeps) of hydrogels.
• Comparison of hydrogel properties with porcine vitreous bodies.
• Determination of recovery times, pH, and osmolality of tested gels.

Main Results:

• Phosphate-buffered saline was adjusted to match vitreous body pH and osmolality.
• Gellan gum-hyaluronic acid and hyaluronic acid-agar hydrogels demonstrated the most promising properties.
• Optimized concentrations of these hydrogels matched vitreous body viscosity and loss factor.

Conclusions:

• Gellan gum-hyaluronic acid and hyaluronic acid-agar hydrogels are suitable in vitro vitreous body substitutes.
• These hydrogels exhibit comparable physicochemical and rheological properties to native vitreous.
• Further diffusion studies are recommended to confirm their utility in drug delivery research.