1.Advances in basic research related to immunogenicity of allogeneic tendon
Xionggang YANG ; Yuande ZHANG ; Yongcheng HU
Chinese Journal of Orthopaedics 2018;38(22):1395-1402
Tendon transplantation is one of the most commonly used procedures for patients with injured tendons.The materials used for tendon transplantation include the tendon autograft,tendon allograft,xenogenic tendon and artificial ligament.Of these,the allogeneic tendon has become more and more widely accepted because of the abundant donor source,absence of complications at donor sites and reduced operation time.However,it would meanwhile increase the risks of immunological rejection,disease transmission and delayed tendon-bone integration.A lot of studies have reported many processing technics to solve thementioned drawbacks of tendon allograft.Regarding to the immunological rejection,many approaches have been proposed including physical freezing (such as deep freezing,freeze drying and cryopreservation using the vitrification method) and chemical decellularization (such as deoxyguanosine culture solution,trinbutyl phosphate,chloroform / methyl alcohol,sodium dodecyl sulfate,95% ethanol and Triton X-100).Among the physical freezing methods,freeze-drying could remove the immunogenicity of tendon more effectively,but it also tends to cause damage to the mechanics,structure and histology of the tendon.And it is more likely to cause damage to tendon especially when the method is used in combination with irradiation sterilization.Deep freezing has less damage to the mechanical and histological characteristics of tendon,and this method is currently the mostcommonly used in clinical and scientific research.The vitrification preservation method has unique advantages in protecting thetendon mechanical properties and cell activity.It retains similar mechanical properties to fresh tendons.However,the complicated preparation procedures involved in this method,the high cost and the cytotoxicity of the cryoprotectant have always restrictedits application in actual production.Different chemical decellularization methods have their own advantages and disadvantages when used to reduce the immunogenicity of tendons.In order to achieve more thorough removal of cellular components in tendonswhile maximally retaining the structural and mechanical integrity of tendons,strict control on the concentration of the decellularizing agent and the treatment time is often required.