Leveraging immune-fibroblast interactions for biomaterial induced skin regeneration

项目概要 天然皮肤元素——毛囊、汗腺和脂肪组织的再生是一个备受关注的问题 伤口愈合结果后。原则上，成年小鼠的非常大的皮肤伤口可以自发地 再生新毛囊和新脂肪细胞，常研究小鼠小伤口和临床伤口 在人类中，愈合时留下的纤维化疤痕远不太理想。是否以及如何直接更换成人皮肤伤口 随着天然皮肤元素的再生，疤痕愈合的自然趋势仍然未知。 该应用的灵感来自于一个偶然的发现，即在我们的新型生物材料中添加抗原，即 微孔退火颗粒 (MAP) 水凝胶，添加到毛囊中后可诱导新毛囊再生 通常是纤维化的小老鼠皮肤伤口。这种免疫调节 MAP 凝胶可提供伤口驻留免疫 具有引发适应性免疫反应以增强巨噬细胞反应的分子触发器的细胞。 此外，我们对自然再生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毛囊再生至关重要。 通过综合生物工程、生物信息学和实验方法，该应用程序将 重点测试我们的新假设，即通过设计 MAP 凝胶使其具有特定的免疫触发因素、相互作用 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改变正常的促纤维化愈合反应 进入非常理想的再生反应。拟议研究的首要目标是机械地建立 MAP 制剂所需的淋巴细胞和巨噬细胞亚群以及分子信号传导途径 我们创造的目的是促进毛囊再生。这将通过生物信息学分析来实现 单细胞分辨率的转录组学、蛋白质组学和功能分析。证实体内功能丧失/ 转基因小鼠研究缺乏关键的免疫途径或细胞 MAP 凝胶。第二个目标是设计新的 旨在最大限度地诱导 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最大限度地减少促纤维化信号。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，这是伤口成纤维细胞的先决条件 新头发再生。这将通过对单细胞转录组的先进生物信息学分析来实现 关于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。 该研究前提基于新接受发表的和广泛的初步数据。拟议的 研究意义重大，因为它们将建立新的免疫细胞驱动机制来增强成纤维细胞 成人伤口中天然皮肤元素的可塑性和激活胚胎样再生。拟议的 研究具有创新性，因为它们将建立新型免疫调节生物材料，以及新的 生物材料触发成人组织再生反应的范例。未来，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，以供潜在的临床使用。

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.