Performance of novel bioactive hybrid hydrogels in vitro and in vivo used for artificial cartilage.

The long-term fixation of poly(vinyl alcohol) PVA hydrogels cartilage implants on ambient tissue is a difficult problem, which is one of the obstacles for PVA hydrogels to be used as articular cartilage implants. In this work, a novel bioactive PVA/HA hydrogel was prepared by the in situ sol-gel synthesis method. Simulated experiments were performed to evaluate and compare the bioactive ability and properties of the hydrogels in simulated body fluid (SBF). Gradual-structure PVA/HA cartilage implants were developed and used to repair articular cartilage defects in rabbit knees. In vitro bioactive evaluation showed that PVA/HA hydrogels could be bio-mineralized to form bone-like hydroxyl-carbonate-apatite deposit in SBF solution. The macroscopic and histological observation of animal experiments displayed that the implanted hydrogels combined tightly with ambient tissues, and some bone-like tissue grew into the bottom of the implants from the base bone to form more deep-set binding between replacement and cartilage tissues.