Test of tissue tolerance to domastic prosthetic materials (carbon fiber mesh, siliconized velvet, silk cloth and dacron cloth) as a subcutaneos transplant was performed in the adcominal wall of rabbit. These implants and their surroundding tissues were excied for studies at second , fourth, eighth and the twelfth weeks after operation. Ratio of fibroblast count to inflammatory cells count which is a common parameter of tissue tolerance was calculated in these four groups. The result shows that fibroblastic cell reaction elicited by carbon fiber mesh is the greates among the four prosthetic materials, the second one is dasron cloth. The inflammatory cell reaction elicited by silk is the greatest among the four materials, the second is carbon fiber mesh, and the dacron cloth the least. Tissure tolerance of dacron cloth is the best in the four prosthetic materials for implantation while sick is the worst.
Objective To evaluate the biological safety of continuous carbonfiber reinforced polyolefin as hard tissue repair material. Methods Biocompatibility of the material was evaluated through hemolysis test, pyrogen test,skin irritation test, cytotoxicity test, ames test,in vitro chromosome aberration test, and bone marrow cells Micronuclei test. Results No obvious hemolysis, pyrogenic characteristics, sensitivity, cytotoxxicity, and mutagenicity were observed. Conclusion The continuous carbonfiber reinforced polyolefin composite material is of good biological safety. It meets all the demand made by biological safety as hardtissue repair material.
In order to investigate the possibility of repairing injuried tendon with living artificial tendon, after combining culture, subcultured autogenous tendon cells with carbon fibers were implanted into the calcaneous tendon of rabbits. In different stages, the synthesis of type I collagen and their relevant morphological changes were observed. The results showed as follows: after implantation, tendon cells continued proliferating. Four weeks after implantation, tendon cells were detached from the carbon fibers and proliferated and produced collagen among the carbon fibers. The collagen fibrils were linked with each other to formed a dense structure. In the linkage site, the collagen fibrils originated from the implants joined to that from the ruptured end of the tendon, which meaned that the implant was healed with the recipient tendon. Observed under scanning electronic microscope, the tendon cells were lined among the carbon fibers evenly and in order, the collagen fibrils joined each other and formed an network, the fibrils were lined parallel to the carbon fibers. Under transparent electron microscope, the nucleolus were clear and organelle were abundant.
A mechanical study on the bones of 29 rabbits following implantation of carbontendon was carried out. The rabbits were divided into seven groups according to the observation time (2,4,6,8,12,20 and 30 weeks after operation). A bundle of artificial tendon composed of 7,000 carbon fibers was passedthrough a tunnel in the tibia, and both ends of the artificial tendon were ligated to the muscle fibers. The mechanical strength and histological structure of the carbonbone junction and their relationship were studied in each group. Carbon fiberwas split and degradated in six to eight weeks after operation. The tensile strength of carbontendon in the soft tissue was decreased from 82±4.6N in the second week to 27±5.31N and6.3±1.81N in the sixth and eighth week respectively. The tensile strength of carbontendon increased from 3.01±1.2N to 6.1±2.01N at the carbon -tendon-bone junction in the bone. The tensile strength of carbon-tendon was unsatisfactory for implantation into bone. The carbon-tendon was split and degradated and the tensile strength was not b enough to cope with the early functional exercises.
Fourteen patients with anterior cruciate ligament (ACL) injuries were treated with carbon fiber—superficial fascia complex and were followed up with an average of 25 months. The overall results in our series were excellent or good. The patients had stable knees and few had some subjective complaints. The influence on the knee function after injury of ACL was discussed.