基于3D打印及组织工程技术构建精确阴茎形态软骨支撑体

Penile defect is a clinically tough problem. Autologous skin flap combined with the penile supporting body is the primary treatment for penile reconstruction, and the therapeutic effect mostly depends on the choice of the supporting body. Currently used supporting bodies, autologous cartilage/bone and artificial prosthesis, have critical restrictions and limitations, such as imprecise penis morphology, resorption of the heterotrophic cartilage/bone, severe damage of donor sites, and immunological rejection. Tissue engineered cartilage can overcome the shortcomings of these supporting bodies, and then become the ideal choice of penis supporting bodies. However, there are still existing problems to be settled for tissue engineered cartilage for penis supporting bodies, such as accurate simulation of penis morphology, poor mechanical strength, and cavity of large-sized engineered cartilage. In an effect to overcome these problems in a package of proposals, we designed an model of preparation of penis-shaped scaffolds with rigid kernel of PCL as well as cell scaffold of PGA/PLA. On this basis, we have successfully prepared 20% the size of human penis, penis-shaped 3D scaffolds, and then constructed tissue engineered human-penis-shaped cartilage. On the basis of previous study, we will further the researches in the following aspects, constructing tissue engineered penis-shaped cartilage supporting body of 100% the size of human penis, parameter optimizing of scaffold preparation and the culture condition in vitro, large animal model to test the therapeutic effect of penis-shaped tissue engineered cartilage for penis reconstruction, simulation of clinical surgery and postoperative care in the large animal model. All the efforts are devoted to clinical translation of penis-shaped tissue engineered cartilage for penis reconstruction.

阴茎缺损是临床治疗难题，阴茎再造术是目前主要治疗方式，阴茎支撑体选择是手术关键。目前常用支撑体：自体软骨或骨、人工假体，存在外形不精确、供区损伤和免疫排斥反应等诸多局限性。组织工程再生软骨能够克服目前支撑体的缺陷，有望成为阴茎支撑体的理想选择。组织工程技术构建阴茎软骨支撑体仍存在精确形态控制、力学强度维持、大片软骨构建中空三大瓶颈问题。课题组提出“PCL刚性内核+PGA/PLA细胞支架”精确人阴茎形态复合支架制备模型，形成了针对上述难题的“一揽子”解决方案。项目组前期研究已初步制备出精确人阴茎形态、20%人阴茎大小的支架，并体外构建出精确人阴茎形态软骨支撑体。本项目拟在前期研究的基础上，构建100%人阴茎大小的支撑体，对支架材料制备等关键技术参数进一步优化，完成组织工程软骨支撑体阴茎再造的大动物有效性验证，并进行临床手术方案模拟及术后护理方案优化，推动组织工程技术构建阴茎支撑体的临床转化。

临床上阴茎缺损仍然是治疗难题，目前主要治疗方式是阴茎再造术，而选择合适的阴茎支撑体是手术成功的关键。然而，迄今为止仍然未找到理想的阴茎支撑体用于临床治疗推广。近年来快速发展的组织工程技术为构筑适合的阴茎支撑体提供了新的方向，基于组织工程技术再生的软骨组织能够克服目前阴茎支撑体的缺陷，有望成为阴茎支撑体的理想选择。组织工程技术构建阴茎软骨支撑体仍存在精确形态控制、力学强度维持、大片软骨构建中空三大瓶颈问题。为此，我们首先将明胶和透明质酸制备成水凝胶，并采用3D打印以确保外部3D形状和内部孔隙结构的精确控制。通过整合光固化3D打印和冷冻干燥技术，明胶和透明质酸被成功地制备出形态精确可控的支架。在体外和自体山羊模型中，与软骨细胞结合的支架成功地再生了具有典型腔隙结构和软骨特异性细胞外基质的成熟软骨。目前的研究为天然聚合物建立了新的支架制造策略，并为软骨再生提供了一种具有令人满意的外形、孔隙结构、机械强度、降解率和弱免疫原性的新型天然3D支架。随后我们基于鱼胶原，开发了一种由FC和聚己内酯（PCL）组成的的电纺纳米纤维膜，并证明该电纺FC/PCL膜是一种非常有前景的软骨再生支架。本研究建立的研究模型为基于电纺FC/PCL膜的软骨和其他组织再生提供了借鉴作用。其次我们还开发了一种环状多孔丝素蛋白（SF）增强脱细胞软骨基质（DCM）（DCM/SF）支架，该支架具有合适的孔径（206.7±12.5μm）和孔隙率（92.7±2.5%），并且对细胞定植具有生物相容性，体外和体内实验均证实DCM/SF支架明显促进了嵌入骨髓干细胞（BMSCs）的软骨形成。本项目为构建100%人阴茎大小的支撑体，对支架材料制备等关键技术参数进一步优化，为推动组织工程技术构建阴茎支撑体的临床转化奠定基础。