Leveraging immune-fibroblast interactions for biomaterial induced skin regeneration

项目摘要 天然皮肤元素的再生-毛囊，汗腺和脂肪组织，是一个高度重视 伤口愈合后的结果。虽然原则上，成年小鼠的非常大的皮肤伤口可以自发地 再生新的毛囊和新的脂肪细胞，通常在小鼠和临床伤口中研究小伤口 在人类中愈合，但纤维化疤痕远不理想。如果以及如何成人皮肤伤口可以直接更换 疤痕愈合与天然皮肤成分再生的自然趋势仍然未知。 这项应用的灵感来自于一个偶然的发现，将抗原加入到我们的新型生物材料中， 微孔退火颗粒（MAP）水凝胶，当加入到毛囊中时，可以诱导新毛囊的再生。 正常纤维化的小老鼠皮肤伤口。这种免疫调节MAP凝胶提供伤口驻留免疫 细胞与分子触发，引发适应性免疫反应，以增强巨噬细胞的反应。 此外，我们对自然再生的非常大的皮肤伤口模型的研究表明，巨噬细胞成纤维细胞 相互作用对于刺激新的毛囊再生是必不可少的。 通过综合生物工程，生物信息学和实验方法，该应用将 重点是测试我们的新假设，即通过设计MAP凝胶具有特定的免疫触发因子， 伤口中T细胞、巨噬细胞和成纤维细胞之间的相互作用可以转化为正常的促纤维化愈合反应 转化为非常理想的再生反应本研究的第一个目的是从机械上建立 淋巴细胞和巨噬细胞亚群以及MAP制剂所需的分子信号传导途径 我们创造了一种能引发毛囊再生的方法这将通过生物信息学分析来实现， 转录组学、蛋白质组学和单细胞分辨率的功能分析。证实体内功能丧失/ 缺乏关键免疫途径或细胞的转基因小鼠研究MAP凝胶。第二个目标是设计新的 设计用于最大程度诱导T细胞和巨噬细胞促再生的免疫调节MAP凝胶类型 信号，同时使用高通量体外测定使促纤维化信号最小化。第三个目标是确定 MAP凝胶诱导的免疫信号如何增强伤口成纤维细胞的谱系可塑性， 新的头发再生。这将通过对单细胞转录组的先进生物信息学分析来实现。 伤口免疫细胞和成纤维细胞的数据和功能获得和功能丧失研究。 研究前提是基于新接受的出版物和广泛的初步数据。拟议 这些研究意义重大，因为它们将建立新的免疫细胞驱动机制， 可塑性和激活成人伤口中天然皮肤成分的胚胎样再生。拟议 研究是创新的，因为它们将建立新型的免疫调节生物材料， 生物材料引发的成人组织再生反应的范例。将来，这项研究的结果 将推动下一代免疫调节伤口生物材料的开发，以用于潜在的临床应用。

PROJECT SUMMARY Regeneration of native skin elements – hair follicles, sweat glands and adipose tissue, is a highly thought after outcome of wound healing. While, in principle, very large skin wounds in adult mice can spontaneously regenerate new hair follicles and new adipocytes, commonly studied small wounds in mice and clinical wounds in humans heal with a far less desirable fibrotic scarring. If and how adult skin wounds can be directed to replace the natural tendency for healing with a scar with regeneration of native skin elements remains unknown. This application is inspired by a serendipitous discovery that adding an antigen to our novel biomaterial, the Microporous Annealed Particle (MAP) hydrogel, can induce regeneration of new hair follicles when added into normally fibrotic small mouse skin wounds. This immunomodulatory MAP gel provides wound-resident immune cells with the molecular triggers that elicit an adaptive immune response to enhance macrophage responses. Further, our studies on naturally regenerating very large skin wound model show that macrophage-fibroblast interactions are essential for stimulating new hair follicle regeneration. Through an integrated bioengineering, bioinformatic and experimental approach, this application will focus on testing our new hypothesis that by engineering MAP gels to have specific immune triggers, interactions between T-cells, macrophages, and fibroblasts in the wound can transform normally profibrotic healing response into highly desirable regenerative response. The first aim of the proposed research is to mechanistically establish the lymphocyte and macrophage subsets and the molecular signaling pathways required for MAP formulations we have created to elicit hair follicle regeneration. This will be achieved using bioinformatic analyses of transcriptomics, proteomic, and functional profiling at single-cell resolution. confirmed with in vivo loss of function/ transgenic mouse studies lacking key immune pathways or cells MAP gels. The second aim is to engineer new types of immunomodulatory MAP gels designed to maximally induce T-cells and macrophage pro-regenerative signals while minimizing pro-fibrotic signals using a high-throughput in vitro assay. The third aim is to determine how MAP gel-induced immune signals enhance lineage plasticity of wound fibroblasts that is prerequisite for new hair regeneration. This will be achieved via an advanced bioinformatic analysis on single-cell transcriptomic data and functional gain- and loss-of-function studies on wound immune cells and fibroblasts. The study premise is based on newly accepted-for-publication and extensive preliminary data. The proposed studies are significant because they will establish new immune cell-driven mechanism for enhancing fibroblast plasticity and activating embryonic-like regeneration of native skin elements in adult wounds. The proposed studies are innovative because they will establish new types of immune-modulating biomaterials, and new paradigm of biomaterial-triggered regenerative response in adult tissues. In the future, the results of this study will drive the development of next-generation immune-modulating wound biomaterials for potential clinical use.