Collaborative Research: Composite vascularized niches for optogenetically actives beta-cells

生物人工组织的设计和制造带来了巨大的挑战，但对于开发针对重大疾病的有效疗法至关重要。这类组织通常需要大量的功能性细胞，如果没有血管系统，这些细胞就无法存活，血管系统有助于营养物质和氧气的运输以及废物的清除。减少所需细胞数量的一种方法是利用光作为刺激来增强它们的功能。根据先前的研究，当蓝光刺激胰腺分泌胰岛素的β细胞时，胰岛素分泌量增加2- 3倍。此外，使用适当的生物材料可以促进合成组织中血管网络的形成。该项目旨在开发设计原则，并利用一种用于糖尿病管理的新型胰腺组织等效物，利用光激活细胞解决植入式工程组织的基本生物学问题。近10%的美国人患有糖尿病，医疗费用最高。所有1型糖尿病患者和30%的2型糖尿病患者完全依赖外源性胰岛素。然而，血糖控制是次优的，并不能避免严重的长期并发症。该项目将通过生物材料的发现和创新以及细胞和组织工程来解决这些问题，从而推进相关技术，提高糖尿病患者的生活质量。这项研究与教育活动交织在一起，包括为STEM领域的本科生和研究生提供跨学科培训，向K-12学生和公众推广，以及促进生物工程科学的多样性。这个项目是由一个迫切需要开发植入式工程组织来重建重要的身体过程，如血糖（BG）稳态。这样的组织需要大量的细胞和支撑血管网络的形成，这通常会持续几周。为了满足这一需求，该项目建议使用光基因工程的人类β细胞，在光照下，β细胞的葡萄糖刺激胰岛素分泌（GSIS）增加2- 3倍，以改善糖尿病高血糖。首先，将设计和构建基于明胶的工程组织，其中包括产氧微粒（OGMs）和光基因工程的人类β细胞，这些细胞被包裹在海藻酸盐中。基本的设计参数，如细胞的比例，支持OGMs和水凝胶配方将被确定。根据复合水凝胶的特性，人类内皮细胞将被纳入支架，形成血管网络。在光基因工程、葡萄糖反应性β细胞存在的情况下，将为支架内血管生成建立条件。最后，工程组织的功能将在糖尿病小鼠模型中进行评估。这项研究将解决光激活细胞的使用、合成组织中血管网络的形成以及用合适的生物材料连接细胞以获得最佳体内功能等方面的独特障碍。这些是设计可调组织系统用于治疗糖尿病等重大疾病时的普遍考虑因素。此外，这里开发的具有光活化人类β细胞的组件将成为β细胞生理学基础研究急需的资源。该奖项反映了美国国家科学基金会的法定使命，并通过基金会的智力价值和更广泛的影响审查标准进行了评估，认为值得支持。

The design and manufacturing of bioartificial tissues pose great challenges yet are essential for developing effective therapies for major diseases. Such tissues typically require a large number of functional cells, which cannot survive without vasculature that facilitates the transport of nutrients and oxygen and the removal of waste products. One way to reduce the requisite number of cells is to amplify their function using light as the stimulus. Based on previous work, pancreatic insulin-producing β-cells exhibit 2- to 3-fold higher glucose-stimulated insulin secretion when stimulated with blue light. Moreover, vascular network formation in synthetic tissues can be promoted with the use of appropriate biomaterials. This project seeks to develop design principles and address fundamental biological issues of implantable engineered tissues with light-activatable cells utilizing a novel pancreatic tissue equivalent developed for the management of diabetes. Diabetes afflicts almost 10% of the US population with the highest healthcare costs. All persons with type 1 diabetes and 30% of those with type 2 diabetes rely exclusively on the administration of exogenous insulin. However, blood glucose control is suboptimal and does not avert serious long-term complications. The project will address these issues through biomaterial discovery and innovation and cell and tissue engineering, thereby advancing relevant technologies that improve the quality of life of persons with diabetes. The research is intertwined with educational activities including interdisciplinary training for undergraduate and graduate students in STEM fields, outreach to K-12 students and the public, and promoting diversity in bioengineering sciences.This project is driven by a critical need to develop implantable engineered tissues for reconstituting vital bodily processes such as blood glucose (BG) homeostasis. Such tissues require significant numbers of cells and the formation of a supporting vascular network, which typically spans a few weeks. To address this need, this project proposes the use of optogenetically engineered human β-cells, which show 2- to 3-fold greater glucose-stimulated insulin secretion (GSIS) with illumination, to ameliorate diabetic hyperglycemia. First, a gelatin-based engineered tissue will be designed and constructed with oxygen-generating microparticles (OGMs) and optogenetically engineered human β-cells encapsulated in alginate. Essential design parameters such as the ratio of cells to supporting OGMs and the hydrogel formulation will be determined. Upon characterization of the composite hydrogels, human endothelial cells will be incorporated into the scaffolds to form a vascular network. Conditions will be established for intra-scaffold angiogenesis in the presence of optogenetically engineered, glucose-responsive β-cells. Finally, the functionality of the engineered tissue will be evaluated in a mouse model of diabetes. The research will address unique hurdles in the use of light-activatable cells, vascular network formation in synthetic tissues, and interfacing cells with suitable biomaterials for optimal in vivo function. These are universal considerations in the design of tunable tissue systems for the treatment of major maladies such as diabetes. Additionally, assemblies with photoactivatable human β-cells developed here will be a much-needed resource for basic research on β-cell physiologyThis 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.