Biphasic Porous Bijel-Like Structures with Hydrogel Domains as Controlled Drug Delivery Systems

Area of Science:

• Materials Science
• Colloid and Surface Chemistry
• Polymer Science

Background:

• Bijels are Pickering emulsions with bicontinuous morphology, stabilized by nanoparticles (NPs).
• Their dual nature allows simultaneous release of hydrophilic and hydrophobic compounds, leading to applications in biological and food industries.
• Existing bijel structures, often using polycaprolactone, face challenges in thermal stability and aqueous degradation.

Purpose of the Study:

• To investigate the effect of modifying the aqueous phase of bijels by incorporating alginate.
• To evaluate the impact of calcium chloride (CaCl2) treatment on alginate-modified bijels.
• To assess the changes in swelling behavior, rheological properties, and drug release performance.

Main Methods:

• Bijel formation using a hydrophobic monomer (polycaprolactone) and nanoparticle stabilization.
• Incorporation of alginate into the aqueous phase of the bijels.
• Treatment of bijels with calcium chloride (CaCl2) solution.
• Analysis of swelling behavior, rheological properties (G'), and drug release kinetics.

Main Results:

• Alginate addition significantly enhanced swelling behavior (150% vs. 25% for control) and rheological properties (G' 100 kPa vs. 20 kPa for control).
• Complete release of hydrophilic drugs was observed in alginate-modified bijels, compared to 20% in control.
• Hydrophobic drug release improved to 35% in 8 hours from 5% in control bijels.

Conclusions:

• Modifying the aqueous phase of bijels with alginate and CaCl2 treatment substantially improves their stability and performance.
• The enhanced bijel system demonstrates superior swelling, mechanical strength, and dual drug release capabilities.
• This strategy opens new avenues for diverse applications of advanced bijel materials.