Preparation of macroporous poly(2-hydroxyethyl methacrylate) hydrogels by enhanced phase separation

Area of Science:

• Materials Science
• Polymer Chemistry
• Biomaterials Engineering

Background:

• Poly(2-hydroxyethyl methacrylate) (p(HEMA)) hydrogels are widely used biomaterials.
• Controlling hydrogel porosity is crucial for applications like drug delivery and tissue engineering.
• Fabrication methods often require precise control over pore formation.

Purpose of the Study:

• To investigate the effect of NaCl concentration on the formation of macroporous p(HEMA) hydrogels.
• To characterize the resulting hydrogel morphology, swelling behavior, and mechanical properties.
• To establish a method for controlled fabrication of macroporous hydrogels.

Main Methods:

• Preparation of p(HEMA) hydrogels using varying concentrations of NaCl (0.3-0.7 M) during polymerization.
• Pore morphology analysis.
• Swelling studies to determine equilibrium water content and porosity.
• Mechanical testing (elastic modulus).

Main Results:

• NaCl concentration directly influenced the pore morphology of p(HEMA) hydrogels.
• Increased NaCl concentration during polymerization led to higher equilibrium water content and porosity.
• Equilibrium water content decreased with increasing NaCl in the swelling medium.
• Elastic modulus was unaffected by porosity until pores interconnected.

Conclusions:

• NaCl addition induces multi-phase separation during p(HEMA) hydrogel fabrication.
• This process allows for the controlled creation of macroporous hydrogels with tunable morphology.
• The findings offer a method for tailoring hydrogel properties for specific applications.