Releasable agarose-hyaluronan hydrogel with anti-friction performance and enhanced stability for artificial joint applications

Hyaluronic acid (HA) as a major constituent of bionic synovial fluid (BSF) has significant role in lubrication of human body hip joint. Those who mostly suffer from joint related disease prefer to try injections of synovia over of total hip replacement (THR). However, affection of the metabolism process to the injected synovia is able to decrease the life time of the prostheses. In this study, injectable and thermosensitive agarose hydrogel as a carrier for hyaluronic acid has been investigated to extend the life time of the artificial hip joints. Experimental evidences reveal bioactivity, superior viscoelasticity and naturally amorphous network structure of the HA. This material in combination with the large molecules of agarose is able to create three-dimensional polymeric network for separating the conterminous surfaces of bearings and improve the lubrication with more than 30 % reduction rate for coefficient of the friction. Role of mechanical and rheological properties of designed polymeric network in cumulative sustained released of lubricants has been widely investigated. Novelty of the present work provides a survey to the long-term lubrication of artificial hip joints.