Hydrophilic–hydrophobic hydrogels for cartilage replacement

A new class of hydrogels combining both hydrophilic and hydrophobic structures are presented. Hydrogels have been investigated as cartilage replacement materials due to the high water content potentially leading to low friction, low wear, and rubbery or pliable nature similar to native cartilage. Unfortunately, many of these hydrogels lack the required shear, tear, and creep strength necessary to be used as cartilage replacement materials. The new hydrogels presented here utilize hydrophobic domains to reinforce the structure and provide higher tear, shear, and creep strengths versus traditional hydrogels without sacrificing water content, low friction and pliability. The mechanical properties of some of these gels are reported, and it is shown that the strength and creep resistance are greatly improved through the addition of hydrophobic segments without negatively impacting the friction. As such, these new gels may be a candidate for use to repair or replace articular cartilage.