Ahn Jeffrey M, Mao Jeremy J
Department of Otolaryngology-Head & Neck Surgery, College of Physicians & Surgeons, Columbia University Medical Center, New York, New York 10032, USA.
Facial Plast Surg. 2010 Oct;26(5):413-20. doi: 10.1055/s-0030-1265022. Epub 2010 Sep 17.
Current autologous fat grafting technique suffers from the drawbacks of donor site morbidity and, more importantly, significant resorption of the grafted fat. Adipose tissue engineering using adult human stem cells has been found to overcome the shortcomings of autologous fat grafting in reconstructing facial defects. Mesenchymal stem cells that can self-renew and differentiate into mature adipocytes have been used to generate adipose tissue, in both in vitro and in vivo cell transplantation studies. However, long-term maintenance of the shape and dimension of the produced adipose tissue remains a challenge, even in tissue engineering with cell transplantation. The choice of appropriate scaffolds to promote stem cell adhesion, proliferation, and differentiation is essential for successful adipogenesis. Recent advances in nanotechnology allow the development of nanostructured scaffolds with a cellular environment that maximally enhances not only cell expansion but also the neovascularization that is crucial for long-term maintenance of cell volume. Cell homing is a technique that actively recruits endogenous host stem cells into a predefined anatomic location for the desired tissue generation. Bypassing ex vivo cell manipulation, the cell homing technique eliminates donor site morbidity and rejection, reducing the regulation issue in clinical translation. Mao et al. introduced the concept of biosurgery, which combined nanostructured scaffolds and growth factor biocues, with or without cell transplantation, for successful de novo adipogenesis in restoring facial defects. Important questions, such as the necessity of cell transplantation in scaling up the size of engineered adipose tissue, need to be answered with further studies. However, the era of biosurgery replacing conventional treatments such as biologically inactive filler injections and alloplastic implants appears to be in the near future.
当前的自体脂肪移植技术存在供区发病的缺点，更重要的是，移植的脂肪会大量吸收。利用成人干细胞进行脂肪组织工程已被发现可克服自体脂肪移植在修复面部缺损方面的缺点。能够自我更新并分化为成熟脂肪细胞的间充质干细胞已被用于在体外和体内细胞移植研究中生成脂肪组织。然而，即使在细胞移植的组织工程中，所产生脂肪组织的形状和尺寸的长期维持仍然是一个挑战。选择合适的支架以促进干细胞的粘附、增殖和分化对于成功的脂肪生成至关重要。纳米技术的最新进展使得能够开发具有细胞环境的纳米结构支架，这种环境不仅能最大程度地促进细胞扩增，还能促进对维持细胞体积至关重要的新血管形成。细胞归巢是一种将内源性宿主干细胞主动招募到预定义解剖位置以生成所需组织的技术。绕过体外细胞操作，细胞归巢技术消除了供区发病和排斥反应，减少了临床转化中的监管问题。毛等人引入了生物手术的概念，该概念将纳米结构支架和生长因子生物信号结合起来，无论有无细胞移植，用于在修复面部缺损中成功进行脂肪新生。诸如在扩大工程化脂肪组织尺寸时细胞移植的必要性等重要问题需要通过进一步研究来解答。然而，生物手术取代诸如生物惰性填充剂注射和异体植入物等传统治疗方法的时代似乎即将到来。
