Department of Laboratory Animal Science, College of Basic Medicine, Third Military Medical University, Chongqing, China.
Burns. 2010 Jun;36(4):533-8. doi: 10.1016/j.burns.2009.08.001.
It is widely recognised that take of grafts is strongly influenced by tissue viability. Although porcine skin is currently the most widely used xenograft, the viability change of pigskin in vitro has not been extensively studied. The purpose of this study was to assess the change of the viability of Bama miniature pigskin after harvest and cryopreservation, and to set up a guideline for pigskin preservation and storage that would allow the skin to retain the highest viability after treatment and still be used in the clinical applications.
Harvested pigskin grafts were divided into five groups: normal saline medium/4 degrees C (group 1), Dulbecco's minimum essential medium (DMEM)/4 degrees C (group 2), normal saline medium/25 degrees C (group 3), DMEM/25 degrees C (group 4) and cryopreserved (group 5). In our experiment, the viability was investigated by 3-(4,5)-dimethylthiazol-2,5-diphenyl tetrasolium bromide (MTT) salt assay. We also evaluated the transplantation performance of preserved skin in different conditions by using a rat recipient model, in which primary take was evaluated by gross observation and predetermined histological criteria after 7 days.
Skin stored at 4 degrees C showed a very slow viability decrease with time. The sample showed a viability decrease of about 70% after 3 days in normal saline and 4 days in DMEM medium. Nevertheless, skin stored in DMEM at 25 degrees C underwent a viability increase during the first 4h and then decreased gradually to about 70% after 20 h, while the viability declined very quickly for skin grafts stored in normal saline medium at 25 degrees C, and maintained the same viability only within 6h of preservation. On the other hand, cryopreserved skin has been shown to maintain a level of skin metabolism equal to 77% of the fresh sample when measured immediately after thawing, and the viability remained about 70% after 6h at 25 degrees C and 2 days at 4 degrees C in DMEM. The graft performance of skin specimens with 70% viability of fresh skin stored in different conditions has not shown statistical significance compared with fresh pigskin.
Based on these results, we suggest that the conservation period of fresh pigskin should not exceed 72 or 96 h when stored in normal saline or DMEM at 4 degrees C, and should not exceed 6 or 18 h when stored in normal saline or DMEM at 25 degrees C. Cryopreserved pigskin should be stored in DMEM for a maximum period of 48 h at 4 degrees C and 6h at 25 degrees C after thawing.
人们普遍认为，移植物的摄取强烈受到组织活力的影响。尽管猪皮目前是最广泛使用的异种移植物，但猪皮在体外的活力变化尚未得到广泛研究。本研究的目的是评估巴马小型猪皮在收获和冷冻保存后的活力变化，并制定一个猪皮保存和储存的指南，以使皮肤在处理后保持最高活力，并仍可用于临床应用。
采集的猪皮移植物分为五组：生理盐水/4°C（组 1）、DMEM/4°C（组 2）、生理盐水/25°C（组 3）、DMEM/25°C（组 4）和冷冻保存（组 5）。在我们的实验中，通过 3-(4,5)-二甲基噻唑-2,5-二苯基四唑溴盐（MTT）盐测定法研究了活力。我们还通过大鼠受体模型评估了不同条件下保存皮肤的移植性能，其中 7 天后通过肉眼观察和预定的组织学标准评估原发性摄取。
4°C 下储存的皮肤随着时间的推移显示出非常缓慢的活力下降。在生理盐水和 DMEM 培养基中，样本在 3 天后的活力下降约 70%，4 天后活力下降约 70%。然而，在 25°C 下储存在 DMEM 中的皮肤在最初的 4 小时内经历了活力增加，然后逐渐下降到 20 小时后的约 70%，而在 25°C 下储存在生理盐水培养基中的皮肤移植物的活力下降非常快，仅在保存 6 小时内保持相同的活力。另一方面，冷冻保存的皮肤在解冻后立即测量时，其新陈代谢水平保持在新鲜样本的 77%，在 25°C 下保存 6 小时和在 4°C 下保存 2 天的 DMEM 中，活力保持在 70%左右。在不同条件下储存的活力为新鲜皮肤的 70%的皮肤标本的移植性能与新鲜猪皮相比没有统计学意义。
根据这些结果，我们建议在 4°C 下生理盐水或 DMEM 中储存新鲜猪皮的保存期不应超过 72 或 96 小时，在 25°C 下生理盐水或 DMEM 中储存不应超过 6 或 18 小时。冷冻保存的猪皮应在 4°C 下 DMEM 中储存最长 48 小时，解冻后在 25°C 下储存 6 小时。
