John Garner

PCL-PEG block copolymers investigated for joint repair

Blog Post created by John Garner on Nov 19, 2015

PolySciTech Division of Akina, Inc. ( provides a wide array of biodegradable block copolymers for a variety of applications including PCL-PEG block copolymers. Recently PEG-PCL block copolymers were investigated in regards to use as a lubricating surface for artificial knee joints and tested for their ability to withstand simulated ‘walking’ conditions. Read more: Hsu, Chih Yueh, Chin Chung Wei, and Cho Pei Jiang. "Tribological Study of PCL-PEG-PCL Polymer on SiNxHy Base." In Key Engineering Materials, vol. 642, pp. 264-269. 2015.

  “Abstract: Tribological behaviour of polymer and hard coating films is complicated with bio-lubricant. Contacting and kinematic conditions of a knee joint when a person in running was simulated in the study. Substrates of specimens are Ti6Al4V and 316LVM stainless steel. Two kinds of polymer films, PCL-PEG-PCL and mPEG-PCL-mPEG, were used to simulate the tissue of cartilage. The silicon nitride film, SiNxHy prepared by PECVD, was used as a protecting film, and it’s thickness about 1000 nm under the polymer film. The testing device was developed, upper specimen is rotated reversely and the lower one is moved linearly forward and backward for 6 mm. A frequency vibration is applied under the lower specimen to simulate the vibration caused from walking, which is sated 2 Hz. Two torque meters are used for friction measurement in rotational and sliding directions. Experiments simulated vertical vibration, rotary and reciprocating motion. Comparing friction coefficient with different substrates with SiNxHy film, mixture of PCL-PEG-PCL and bovine serum can effectively decrease friction but useless for mPEG-PCL-mPEG. If adhesion of PCL-PEG-PCL polymer can be improved, it has potential in the application of artificial joint. Keywords: Friction, Pin on Disc, Polymer, Vertical Vibration”