Olender E, Uhrynowska-Tyszkiewicz I, Kaminski A
Department of Transplantology and Central Tissue Bank, Warsaw Medical University, Warszawa, Poland.
Transplant Proc. 2011 Oct;43(8):3137-41. doi: 10.1016/j.transproceed.2011.08.069.
Biostatic (nonvital) tissue allografts have been used for temporary replacement as well as to trigger, stimulate, and ensure space for the regeneration of a recipient's own tissues. Examples of biostatic allografts routinely used in clinic are bone, tendons, skin, and amniotic membrane. A characteristic feature of biostatic allografts is the lack of living cells. In the recipient's body, biostatic allografts function as scaffolds as well as sources of growth, differentiation, and chemotactic factors. After implantation, recipient cells migrate onto the graft, colonize it, and initiate synthesis of extracellular matrix, thereby regenerating the structure of the lost or damaged tissue. The allograft gradually degrades before being remodeled and substituted by the recipient's new tissue. However, this process is not always effective due to a lack of reaction by recipient cells. New concepts have proposed seeding recipient cells onto the allograft prior to implantation, that is, biostatic allografts that are revitalized ex vivo. The aim of this presentation was to review scientific publications to provide essential information on the revitalization of biostatic allografts, as a rising trend in tissue transplantology.
Biostatic allografts show the following advantages: they are human-derived, nontoxic, biocompatible, and, in some cases, already display the desired shape. The process of introducing cells into the biostatic graft is described as "revitalization." The cells used in the process are recipient autologous elements that are either differentiated or progenitor elements. Cells are seeded onto the graft directly after retrieval or after propagation in culture. Revitalized biostatic allografts can be used orthotopically for the regeneration of the same tissue they have been retrieved from or heterotopically wherein the graft retrieved from a different tissue is used as a carrier for cells typical for the tissue to be regenerated. Examples of orthotopic use include revitalized trachea, tissue-engineered blood vessels, urinary bladder wall, and revitalized trabecular bone cubes. Examples of heterotopic use include: amniotic membrane as a carrier of limbal stem cells to treat corneal defects, or for chondrocytes to treat articular cartilage defects. Various requirements set by law must be met by tissue banks performing cell seeding of grafts. In Europe, the requirements are described in directives: 2004/23/EC, 2006/17/EC, 2006/86/EC), and in the regulation 2007/1394/EC. Revitalization of biostatic allografts gives new, promising tools for creation of functional parts of organs; brings the methodology used in tissue banks closer to tissue engineering; places the enterprise in the mainstream of advanced biotechnology; allows the full potential of tissue allografts; and opens a new, large area for clinical and laboratory research.
生物静态（无活力）组织同种异体移植物已被用于临时替代，以及触发、刺激并确保受体自身组织再生的空间。临床常规使用的生物静态同种异体移植物的例子有骨、肌腱、皮肤和羊膜。生物静态同种异体移植物的一个特征是缺乏活细胞。在受体体内，生物静态同种异体移植物既作为支架，又作为生长、分化和趋化因子的来源。植入后，受体细胞迁移到移植物上，在其上定植，并启动细胞外基质的合成，从而使丢失或受损组织的结构再生。同种异体移植物在被重塑并被受体的新组织替代之前会逐渐降解。然而，由于受体细胞缺乏反应，这个过程并不总是有效。新的概念提出在植入前将受体细胞接种到同种异体移植物上，即体外活化的生物静态同种异体移植物。本报告的目的是回顾科学出版物，以提供关于生物静态同种异体移植物活化的基本信息，这是组织移植学中一个不断发展的趋势。
生物静态同种异体移植物具有以下优点：它们来源于人类，无毒，具有生物相容性，并且在某些情况下已经呈现出所需的形状。将细胞引入生物静态移植物的过程被称为“活化”。该过程中使用的细胞是受体自体成分，它们可以是分化的或祖细胞成分。细胞在获取后或在培养中扩增后直接接种到移植物上。活化的生物静态同种异体移植物可原位用于其获取组织的再生，或异位使用，即将从不同组织获取的移植物用作待再生组织典型细胞的载体。原位使用的例子包括活化的气管、组织工程血管、膀胱壁和活化的小梁骨块。异位使用的例子包括：羊膜作为角膜缘干细胞的载体用于治疗角膜缺损，或作为软骨细胞的载体用于治疗关节软骨缺损。进行移植物细胞接种的组织库必须满足法律规定的各种要求。在欧洲，这些要求在指令（2004/23/EC、2006/17/EC、200'6/86/EC）和法规（2007/1394/EC）中有描述。生物静态同种异体移植物的活化提供了用于创建器官功能部件的新的、有前景的工具；使组织库中使用的方法更接近组织工程；使企业处于先进生物技术的主流；充分发挥了组织同种异体移植物的潜力；并为临床和实验室研究开辟了一个新的广阔领域。
