Tripeptide-copper complex GHK-Cu (II) transiently improved healing outcome in a rat model of ACL reconstruction

J Orthop Res. 2015 Jul;33(7):1024-33. doi: 10.1002/jor.22831. Epub 2015 Apr 10.


After anterior cruciate ligament reconstruction (ACLR), the biological healing of the graft is a rate-limiting step which can contribute to graft failure. The tripeptide-copper complex glycyl-L-histidyl-L-lysine-Cu(II) (GHK-Cu) is a well-known activator of tissue remodeling. We investigated whether GHK-Cu can improve graft healing following ACLR. Seventy-two rats underwent unilateral ACLR were randomized to saline, 0.3 or 3 mg/ml GHK-Cu groups (n = 24). Post-operational intra-articular injections were given from week 2, once a week, for 4 weeks. Gait analysis was performed pre-injury and at harvesting time. At 6 or 12 weeks post-operation, knee specimens were harvested for knee laxity test, graft pull-out test, and histology. At 6 weeks post-ACLR, GHK-Cu groups resulted in a smaller side-to-side difference in knee laxity as compared to the saline group (p = 0.009), but there was no significant difference at 12 weeks post-operation. The graft complex in the 0.3 mg/ml GHK-Cu group had higher stiffness than saline group at 6 weeks post-operation (p = 0.026), but there was no significant difference in ultimate load, gait parameters, and histological scores among treatment groups. All grafts failed mid-substance during pull-out test. Intra-articular supplementation with a bioactive small molecule GHK-Cu improved graft healing following ACLR in rat, but the beneficial effects could not last as treatment discontinued.

Keywords: anterior cruciate ligament reconstruction; biological modulation; graft remodeling; rat; tripeptide copper complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anterior Cruciate Ligament Reconstruction*
  • Gait / drug effects
  • Injections, Intra-Articular
  • Joint Instability / prevention & control
  • Male
  • Oligopeptides / pharmacology
  • Oligopeptides / therapeutic use*
  • Random Allocation
  • Rats, Sprague-Dawley
  • Transplants / drug effects*
  • Transplants / pathology
  • Wound Healing / drug effects*


  • Oligopeptides
  • glycyl-histidyl-lysine