In vitro platelet adhesion to nonionic and ionic hydrogels with different water contents

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Surface Science

Background:

• Hydrogels are widely used in biomedical applications.
• Platelet adhesion to biomaterials is a critical factor in thrombosis and biocompatibility.
• Optimizing hydrogel properties to minimize platelet interaction is essential for medical device development.

Purpose of the Study:

• To synthesize and characterize various nonionic and ionic hydrogels.
• To investigate in vitro platelet adhesion to these hydrogels.
• To evaluate the influence of water content and protein presence on platelet adhesion.

Main Methods:

• Synthesis of nonionic hydrogels (PAAm, PVA, PEG, etc.) and ionic hydrogels (copolymers) using irradiation and polymerization.
• In vitro platelet adhesion assays using washed rabbit platelets in phosphate-buffered saline.
• Protein sorption studies using fluorescent spectroscopy on PVA hydrogels.

Main Results:

• Nonionic hydrogels exhibited lower platelet adhesion than conventional hydrophobic polymers.
• Minimum platelet adhesion for nonionic hydrogels occurred around 90% water content.
• Polyacrylamide (PAAm) and polyethylene glycol (PEG) hydrogels showed weakest interaction below 90% water content.
• Poly(vinyl alcohol) (PVA) hydrogel had high initial adhesion, but it was reduced by protein presence.
• Positive charges increased platelet adhesion, while negative charges slightly decreased it.

Conclusions:

• Hydrogel water content is a key factor in modulating platelet adhesion.
• Nonionic hydrogels with high water content offer promising low-thrombogenicity surfaces.
• Protein interactions play a significant role in reducing platelet adhesion on specific hydrogels.
• Surface charge influences platelet interaction, suggesting tunable biocompatibility through ionic modification.