CAREER: Modulating Local Tumor Hypoxia using Cryogel Scaffolds to Regulate Dendritic Cell Function and Activity

缺氧是指组织中氧水平的异常下降。虽然不同的组织和细胞对缺氧有不同的阈值和易感性，但在细胞水平上，缺氧和缺氧反应通常发生在约1- 3%的氧气下。令人信服的证据表明，组织氧合减少存在于各种疾病中，尤其是癌症。大量人体实体瘤深度缺氧，表现为肿瘤缺氧区；这种情况主要是由于通过血液循环输送氧气和癌细胞消耗氧气之间的不平衡。缺氧可通过多种机制引起。如快速生长的缺氧肿瘤，血管生物分布差，血管缺损增多，血管数量少。此外，生长出新生血管的高增殖癌细胞也参与肿瘤缺氧。在过去的十年中，越来越多的癌症报告了缺氧区，包括子宫内膜癌、卵巢癌、黑色素瘤、淋巴瘤、乳腺癌、膀胱癌、脑癌、头颈癌、肾癌、结肠癌、胃癌、胰腺癌、前列腺癌和非小细胞肺癌。本课题的研究目标是应用生物材料科学与工程的标准方法模拟低氧肿瘤微环境，更好地了解肿瘤与树突状细胞之间的相互作用，树突状细胞是免疫反应的主要主管。拟议的研究可能为癌症免疫治疗提供新的模式，并有望证明使用缺氧抑制生物材料，增强免疫细胞的杀瘤功能，并最终增加肿瘤排斥反应。该提案的教育目标是向高中生介绍生物材料科学和工程（开发动手科学课程，促进实践研究经验，并促进STEM校园实地考察），提高代表性不足的学生（西班牙裔，非裔美国人和女性）的本科研究曝光和经验，并扩展东北大学的合作模式，包括研究生和学术实验室经验。技术摘要：氧缺乏性癌症通常具有侵袭性，对标准治疗具有耐药性，因此很难根治。更好地了解这些缺氧癌细胞是如何与免疫系统相互作用的，将有助于制定有效的治疗方法，并获得更好的结果。缺氧可以抑制树突状细胞（dc）的分化、抗原捕获、成熟、淋巴结归巢，树突状细胞是免疫反应的主要调节因子，这可以损害下游T细胞的发育、分化和细胞毒性活性。免疫抑制是肿瘤免疫逃避的基本机制之一。因此，扩大我们对缺氧如何影响树突状细胞的理解，找到局部绕过缺氧驱动的免疫抑制并恢复免疫细胞功能和活性的方法是很重要的。为了解决这一需求，本提案的主要研究目标是设计生物材料来调节局部缺氧环境，以了解免疫细胞的功能和活性。为了实现这一目标，本提案有三个目标：1)设计可注射的产氧低温凝胶支架，实现可控的供氧；2)构建B16-F10黑色素瘤肿瘤微环境三维局部供氧，调节固有缺氧和肿瘤诱导的缺氧；3)在体外卵白蛋白（B16-F10/OVA）黑色素瘤模型中，破坏缺氧并调节氧张力，了解局部氧合如何调节树突状细胞的存活和功能，并影响其活性。该提案的长期教育目标是促进和培训下一代科学家在学术界、工业界和临床环境中工作，开发创新的生物材料，以提高人类的生活质量。该计划的主要目标是：1)向K-12学生介绍生物材料科学（开发动手科学课程，实施实践研究经验，并促进STEM校园实地考察），2)向代表性不足的学生（西班牙裔，非裔美国人和女性）增加本科研究曝光和经验，以及3)扩大东北大学合作模式，包括研究生和学术实验室经验。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。

Non-technical AbstractHypoxia is an abnormal decrease of oxygen levels in tissues. Although different tissues and cells have distinct thresholds and susceptibility to hypoxia, at a cellular level, hypoxia and hypoxic responses generally occur at approximately 1-3 % oxygen. Compelling evidence has shown that reduced tissue oxygenation is present in various diseases, and more particularly cancer. A large number of human solid tumors profoundly lack oxygen, exhibiting hypoxic tumor areas; this condition is mainly due to an imbalance between delivery of oxygen via the blood circulation and consumption by cancer cells. Hypoxia can arise via a number of mechanisms. For instance, fast growing hypoxic tumors typically have poor vessel bio-distribution, increased vascular defects, and low vessel number. Furthermore, highly proliferating cancer cells that outgrow the neovascularization also participate in tumor hypoxia. An increasing list of cancers with hypoxic regions has been reported over the last decade and include endometrial carcinoma, ovarian, melanoma, lymphoma, breast, bladder, brain, head and neck, renal, colon, gastric, pancreatic, prostate, and non-small cell lung cancers. The research objective of this proposal is to apply standard methods of biomaterials science and engineering to emulate a hypoxic tumor microenvironment and better understand the interplay between tumor and dendritic cells, the major directors of immune responses. The proposed studies are likely to offer new modalities in cancer immunotherapy and are expected to justify the use of hypoxia-suppressive biomaterials, reinforce tumoricidal functions of immune cells, and ultimately increase tumor rejections. The educational goal of this proposal is to introduce biomaterials science and engineering to high school students (develop hands-on science curriculum, promote practical research experience, and foster STEM field trips to the campus), enhance undergraduate research exposure and experience to underrepresented students (Hispanic, African-American, and female), and expand the Northeastern University co-op model to include graduate and academic lab experiences. Technical AbstractHypoxic cancers are usually aggressive, resistant to standard therapies, and thus very difficult to eradicate. A better understanding of how these hypoxic cancer cells interact with the immune system would allow tailoring of efficient therapies and better outcomes. Hypoxia can inhibit differentiation, antigen capture, maturation, lymph node homing of dendritic cells (DCs), the main regulators of immune responses, which can impair downstream T cell development, differentiation and cytotoxic activity. Immunosuppression represents one of the fundamental tumor immune evasion mechanisms. Therefore, it is important to expand our understanding on how hypoxia affects DCs and find ways to circumvent hypoxia-driven immunosuppression locally and restore immune cell function and activity. To address this need, the primary research objective of this proposal is to engineer biomaterials to modulate the local hypoxic environment to understand immune cell function and activity. To achieve this goal, this proposal has three aims: 1) Design injectable oxygen-generating cryogel scaffolds to controllably deliver oxygen, 2) Engineer a B16-F10 melanoma tumor microenvironment in three-dimension and deliver oxygen locally to modulate inherent and tumor-induced hypoxia, and 3) Disrupt hypoxia and modulate oxygen tension to understand how local oxygenation can regulate dendritic cell survival and function and impact their activity in an in-vitro ovalbumin (B16-F10/OVA) melanoma model. The long-term educational goal of the proposal is to promote and train the next generation of scientists to work in academia, industry and clinical settings developing innovative biomaterials to improve human quality of life. The major aims of this program are: 1) Introduce K-12 students to Biomaterials Science (develop a hands-on science curriculum, implement practical research experience, and foster STEM field trips to campus), 2) Enhance undergraduate research exposure and experience to underrepresented students (Hispanic, African-American, and female), and 3) Expand the Northeastern University co-op model to include graduate and academic lab experiences.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.