Polyhydroxyethylmethacrylate

Polyhydroxyethylmethacrylate_structural.svg

Polyhydroxyethylmethacrylate (PHEMA) is a polymer that is widely used in various biomedical and industrial applications. It is a hydrophilic polymer, meaning it has an affinity for water, which makes it particularly useful in the field of medicine and biotechnology.

Chemical Structure and Properties

PHEMA is synthesized from the monomer 2-Hydroxyethyl methacrylate (HEMA) through a process called free radical polymerization. The chemical structure of PHEMA consists of repeating units of HEMA, which gives it its hydrophilic properties. The polymer is known for its high water content, biocompatibility, and transparency.

Applications

Contact Lenses

One of the most common applications of PHEMA is in the manufacture of soft contact lenses. Its hydrophilic nature allows it to retain water, making the lenses comfortable to wear for extended periods. PHEMA-based contact lenses are known for their oxygen permeability, which is crucial for maintaining corneal health.

Drug Delivery Systems

PHEMA is also used in drug delivery systems due to its biocompatibility and ability to form hydrogels. These hydrogels can be used to encapsulate drugs and release them in a controlled manner, improving the efficacy and reducing the side effects of various medications.

Tissue Engineering

In the field of tissue engineering, PHEMA is used to create scaffolds that support the growth and differentiation of cells. Its biocompatibility and ability to be modified with various bioactive molecules make it an ideal material for developing artificial organs and tissue grafts.

Wound Dressings

PHEMA hydrogels are also used in wound dressings due to their ability to maintain a moist environment, which is conducive to wound healing. These dressings can absorb exudates and provide a barrier against infections.

Synthesis

The synthesis of PHEMA involves the polymerization of HEMA monomers using free radical initiators such as azobisisobutyronitrile (AIBN) or benzoyl peroxide. The polymerization can be carried out in bulk, solution, or suspension, depending on the desired properties of the final product.

Advantages and Disadvantages

Advantages

• High water content
• Biocompatibility
• Transparency
• Versatility in biomedical applications

Disadvantages

• Mechanical strength may be lower compared to other polymers
• Potential for hydrolytic degradation over time

See Also

• Hydrogel
• Biocompatibility
• Polymer chemistry
• Contact lens