CAREER: Tissue Engineering Better Cell Therapies for Wound Healing.

慢性伤口是指皮肤损伤复发或6周后未愈合。在美国，这些伤口影响着650万患者，而且由于糖尿病患者、肥胖者和老年人数量的急剧增加，这个数字还在迅速增长——所有这些人群的伤口愈合都受到了损害。间充质干细胞（通常称为成体干细胞）和应用于伤口表面的胰岛素都显示出愈合其他无法愈合的伤口的希望。间充质干细胞通过分泌促进对伤口愈合至关重要的行为的因子，如新血管的形成，皮肤成分的产生增加，以及清洁伤口和形成疤痕组织的细胞的募集，来帮助伤口愈合。胰岛素通过招募间充质干细胞和皮肤细胞到伤口区域来帮助伤口愈合。最近的观察结果表明，用间充质干细胞和胰岛素生成细胞联合治疗的伤口愈合速度比正常情况下更快，而且没有瘢痕形成，因此，该项目的目标是确定实现所观察到的加速愈合和减少瘢痕形成所需的胰岛素类型，并揭示伤口愈合的途径。研究结果有可能通过实现快速愈合来改变伤口护理，从而避免与慢性伤口相关的发病率和死亡率，并通过减少或消除疤痕形成来提高重建和整形手术的效果。该项目的长期教育目标是为未来的工程师提供在不熟悉的环境（如航空）中进行组织工程研究的机会，以激发未来生物医学工程职业的创新思维。为了实现这一目标，该项目的教育目标是将研究原则应用于教学，并开发集研究、教学、指导和学习于一体的组织工程研究模块，用于生物医学工程本科课程研究经验（CUREs）。教育和推广方法是招募女学生，将她们分组成小组，并提供实践研究活动，包括伤口愈合模型，使她们能够制定假设和模型，并提出、实施和展示实验，以进一步了解研究。这些女性将被要求在科学会议和航空科学俱乐部的K-12年级学生面前展示她们的研究成果。该项目的研究重点是研究间充质干细胞（MSCs）和胰岛素产生细胞（IPCs）对伤口愈合及其途径的影响，以及确定细胞-细胞与细胞-伤口相互作用如何控制被包裹细胞的分泌组。该项目的动力来自PI实验室最近的研究，该研究在结合这些细胞后实现了显著加速（14天vs 40天）的无疤痕伤口愈合。研究计划有四个具体目标。目的1是通过体外研究，剖析IPCs与胰岛素在共包被细胞的存活和功能中的作用，即无论是胰岛素本身，IPCs的存在还是激素的释放，都能改善存活和功能。目的2是通过小鼠体内研究，解剖IPCs与胰岛素在加速伤口愈合中的作用，也就是说，产生胰岛素的成纤维细胞是否与市售的分泌额外产物的IPCs （RIN-5F和RIN-14B）具有相同的效果。目的3是通过体外研究确定，与伤口环境诱导的MSC因子释放相比，共包封促进MSC因子释放的程度，即Akt信号通路在与IPCs共包的MSCs中还是在单独递送至伤口的MSCs中被更强烈地激活，Akt信号通路对MSC存活至关重要。目的4是确定IPCs+MSCs减少疤痕形成的程度，即将工作扩展到猪的有限研究，猪的表皮和真皮与人类皮肤相似，并且愈合速度相当。总之，本项目将研究IPC+MSC伤口愈合的代谢途径，两种细胞与伤口环境之间的相互作用，以及所获得的经验是否可以应用于其他细胞疗法。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Chronic wounds are skin injuries that recur or fail to heal by 6 weeks. These wounds affect 6.5 million patients in the US and this number is growing rapidly due to a drastic increase in the number of diabetics, the obese, and the elderly--all populations in which wound healing is impaired. Mesenchymal stem cells (commonly known as adult stem cells) and insulin applied to wound surfaces have each shown promise in healing otherwise unhealable wounds. Mesenchymal stem cells assist wound healing by secreting factors that promote actions critical to wound healing, such as new blood vessel formation, increases in the production of skin components, and recruitment of cells that clean wounds and form scar tissue. Insulin assists wound healing by recruiting mesenchymal stem cells and skin cells to the wound area. Motivated by the recent observation that wounds treated with a combination of mesenchymal stem cells and insulin-producing cells healed faster than normal and without scarring, the objective of this project is to identify the type of insulin needed to achieve the observed accelerated healing and reduced scarring and to uncover the wound healing pathways that are recruited. Research results have the potential to transform wound care by enabling rapid healing that would avert the morbidity and mortality associated with chronic wounds and to enhance reconstructive and plastic surgery outcomes by reducing or eliminating scar formation. The project's long-term educational goal is to present future engineers with tissue engineering research in unfamiliar contexts, like aviation, to inspire innovative thinking for future careers in biomedical engineering. In pursuit of this goal, this project's educational objective is to apply research principles to teaching and to develop tissue engineering research modules that integrate research, teaching, mentorship, and learning for use in biomedical engineering course-based undergraduate research experiences (CUREs). The educational and outreach approach is to recruit female students, group them in teams and provide hands-on research activities with wound healing models that will enable them to formulate hypotheses and models, and to propose, conduct, and present experiments that will further their understanding of research. The women will be required to present their research in scientific meetings and to K-12 graders in an aviation science club.The project's research focus is on investigating the impact of mesynchymal stem cells (MSCs) and insulin producing cells (IPCs), both individually and coencapsulated, on wound healing and its pathways, and on identifying how cell-cell vs. cell-wound interactions govern the secretome of encapsulated cells. The project is motivated by recent studies from the PI's lab that achieved dramatically accelerated (14 vs 40 days), scar-free wound healing after combining these cells. The research plan has four specific aims. Aim 1 is to dissect, via in vitro studies, the role of IPCs vs insulin in survival and function of the coencapsulated cells, i.e., whether it is insulin itself, the presence of the IPCs or the hormone release that improves survival and function. Aim 2 is to dissect, via in vivo studies in mice, the role of IPCs vs insulin in the accelerated wound healing, i. e, whether insulin-producing fibroblasts have the same effect as commercially available IPCs (RIN-5F and RIN-14B) that secrete additional products. Aim 3 is to determine the extent, via in vitro studies, that coencapsulation promotes MSC factor release in comparison to MSC factor release elicited by wound environments, i.e., whether the Akt signaling pathway, which is critical to MSC survival, is activated more strongly in MSCs coencapsulated with IPCs or in MSCs delivered singly to wounds. Aim 4 is to determine the extent that IPCs+MSCs reduce scar formation, i.e., to extend the work to a limited study in pigs, which have an epidermis and dermis similar to human skin and heal at a comparable rate. In summary, this project will examine the metabolic pathways involved in IPC+MSC wound healing, the interplay between the two cells and the wound environment, and whether lessons learned can be applied to other cell therapies.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.