Patients with severe burns, which cause extensive damage to their skin, require rapid intervention to prevent life-threatening hypothermia, infection, and fluid loss. Current treatments typically involve surgical excision of the burned skin and reconstruction of the wound with the aid of skin autografts. However, there is a lack of donor site in the most severe cases. While alternative treatments such as cultured epithelial autografts and “spray-on” skin can allow much smaller donor tissues to be used (and hence reduce donor site morbidity), they present their own challenges in terms of fragility of the tissues and control of the cell deposition, respectively. Recent advances in bioprinting technology have led researchers to explore its use to fabricate skin grafts, which depend on several factors, including appropriate bioinks, cell types, and printability. In this work, we describe a collagen-based bioink that allows the deposition of a contiguous layer of the keratinocytes directly onto the wound. Special attention was given to the intended clinical workflow. For example, since media changes are not feasible once the bioink is deposited onto the patient, we first developed a media formulation designed to permit a single deposition step and promote self-organization of the cells into the epidermis. Using a collagen-based dermal template populated with dermal fibroblasts, we demonstrated by immunofluorescence staining that the resulting epidermis recapitulates the features of natural skin in expressing p63 (stem cell marker), Ki67 and keratin 14 (proliferation markers), filaggrin and keratin 10 (keratinocyte differentiation and barrier function markers), and collagen type IV (basement membrane protein involved in adherence of the epidermis to the dermis). While further tests are still required to verify its utility as a burn treatment, based on the results we have achieved thus far, we believe that our current protocol can already produce donor-specific model for testing purposes.
展开▼
机译：严重烧伤的患者会对皮肤造成大面积损伤，需要快速干预以防止危及生命的体温过低、感染和体液流失。目前的治疗方法通常包括手术切除烧伤的皮肤，并在皮肤自体移植物的帮助下重建伤口。然而，在最严重的情况下缺乏供体部位。虽然培养的上皮自体移植物和“喷涂”皮肤等替代疗法可以允许使用更小的供体组织（从而降低供体部位的发病率），但它们分别在组织的脆弱性和细胞沉积的控制方面提出了自己的挑战。生物打印技术的最新进展促使研究人员探索其用于制造皮肤移植物，这取决于几个因素，包括适当的生物墨水、细胞类型和可打印性。在这项工作中，我们描述了一种基于胶原蛋白的生物墨水，它允许将角质形成细胞的连续层直接沉积到伤口上。特别关注预期的临床工作流程。例如，由于一旦生物墨水沉积到患者身上，就无法更换培养基，因此我们首先开发了一种培养基配方，旨在允许单个沉积步骤并促进细胞自组织到表皮中。使用填充有真皮成纤维细胞的基于胶原蛋白的真皮模板，我们通过免疫荧光染色证明，所得表皮在表达 p63（干细胞标志物）、Ki67 和角蛋白 14（增殖标志物）、聚丝蛋白和角蛋白 10（角质形成细胞分化和屏障功能标志物）和 IV 型胶原蛋白（参与表皮粘附到真皮上的基底膜蛋白）中概括了天然皮肤的特征。虽然仍需要进一步的测试来验证其作为烧伤治疗的效用，但根据我们迄今为止取得的结果，我们相信我们目前的方案已经可以产生用于测试目的的供体特异性模型。
展开▼
