Mechanical Loading Effects on Degradation Profiles of Peg-Pla Hydrogel Scaffolds for Cartilage Regeneration

Articular cartilage is the tissue that lubricates and bears the load of many joints in the body. It is both avascular and aneural, limiting its ability to regenerate or repair itself. Over one million cartilage replacement surgeries are performed every year due to injury and degeneration. One out of every eight Americans over 25 years of age suffers from arthritis, making it the third most common reason for a hospital visit. Encapsulating chondrocytes in degradable hydrogels is a promising tissue engineering method for cartilage replacement in vivo. Mechanical stimulation plays an important role in the formation of new cartilage. Chondrocytes are known to sense physical forces though a process called mechanotransduction, in which extracellular signals, such as hydrostatic pressure or shear forces, are converted into intracellular biochemical signals that can affect gene expression and tissue quality. For this reason, understanding the effects of physiologic mechanical loading on the degradation profiles of the hydrogel scaffolds is critical. This study examines the effect of loading frequency and polymer structure on the mass loss, swelling, and compressive modulus of degradable hydrogels.