CAREER: Cell-Instructive Smart Bioinks for Tissue and Organ Printing

第一部分：开发能够生产功能齐全的人类规模组织和器官的生物材料，这些组织和器官能够替代失败的器官，这将对社会产生变革性的好处。生物打印可以用于构建高度复杂和患者特异性的组织和器官以及组织界面。尽管有这种潜力，但缺乏能够模拟天然组织动态特性的多种生物墨水是阻碍生物打印全功能组织和器官的主要瓶颈之一。该项目旨在研究材料设计策略，以创建智能生物墨水来解决这一差距，并将这些生物墨水应用于全功能骨软骨（OC）组织的生物打印。特别是，该项目将回答以下基本研究问题：（i）如何通过调节大分子单体性质来控制印刷适性，同时确保高细胞活力;（ii）如何调整印刷适性，刚度，降解和生物活性相互独立;（iii）如何定制化学以实现细胞介导的生物活性操纵，以及（vi）如何指导干细胞在3D生物打印构建体内空间分化以形成OC组织。拟议研究的跨学科性质将为传统上在STEM教育中代表性不足的当地学校的少数民族本科生和高中生提供机会，以获得实践研究经验，培养高素质的劳动力。与新泽西盲人和视力障碍委员会合作的拟议外展计划将提高盲人和视力障碍学生的STEM教育可及性。研究结果将广泛传播给学生、家庭和各级教育工作者。第二部分：生物打印技术在过去几年中已经急剧发展，但是显著缺乏多样和智能的生物墨水，其可以独立地促进3D打印构建体的力学、降解和生物活性的可逆和时空控制，以模拟在组织发育和疾病期间发生的动态细胞外基质（ECM）变化。拟议的研究将专门针对生物打印性和对用户和细胞触发的力学，降解和生物活性变化的响应性定制细胞负载水凝胶的构建模块。这些智能生物墨水将捕捉组织发育、疾病和愈合过程中ECM中发生的动态变化。该项目将利用这些生物墨水来研究发育相关的细胞-基质和细胞-细胞相互作用的时间贡献，以指导干细胞在空间上再生骨软骨（OC）界面。拟议研究的三个目标是：1）合成具有可调印刷性、刚度和降解的新型功能性生物墨水; 2）定制用于细胞触发的生物活性时间控制的侧链化学，以增强干细胞软骨形成; 3）研究智能生物墨水制造用于骨软骨界面再生的异质性构建体的能力。建议的教育计划包括：1）为NJIT和其他大学的本科生开发定制的研究项目; 2）让来自低收入和学生人数不足的当地学校的高中生参与实践研究经验，并提供长期指导; 3）创建一个具有实践实验室组件的生物打印课程模块; 4）提高盲人和视障学生接受STEM教育的可及性。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

PART 1: NON-TECHNICAL SUMMARY Developing biomaterials that enable the production of fully functional, human-scale tissues and organs capable of replacing failed organs would be a transformative benefit to society. Bioprinting could potentially be utilized to construct highly complex and patient-specific tissues and organs as well as tissue interfaces. Despite this potential, the lack of diverse bioinks that can mimic the dynamic properties of the native tissue is one of the major bottlenecks that hinders bioprinting of fully functional tissues and organs. This project aims to investigate materials design strategies to create smart bioinks to address this gap, and to apply these bioinks for bioprinting of fully functional osteochondral (OC) tissues. In particular, this project will answer the following fundamental research questions: (i) how to control printability by adjusting macromer properties while ensuring high cell viability; (ii) how to tune printability, stiffness, degradation and bioactivity independent from each other; (iii) how to tailor chemistry to enable cell-mediated manipulation of bioactivity, and (vi) how to instruct stem cells to differentiate spatially within a 3D bioprinted construct towards OC tissue formation. The interdisciplinary nature of the proposed research will provide opportunities for minority undergraduate students and high school students in local schools traditionally underrepresented in STEM education to gain hands-on research experiences towards development of a highly qualified workforce. The proposed outreach program with the New Jersey Commission for the Blind and Visually Impaired will enhance STEM education accessibility for blind and visually impaired students. Research findings will be disseminated broadly to students, families, and educators at all levels. PART 2: TECHNICAL SUMMARYBioprinting technology has expanded dramatically over the past few years, yet there is a significant lack of diverse and smart bioinks which could facilitate reversible and spatiotemporal control of the mechanics, degradation, and bioactivity of the 3D printed constructs independently to mimic dynamic, extracellular matrix (ECM) changes which occur during tissue development and disease. The proposed research will specifically tailor the building blocks of cell-laden hydrogels for bioprintability and for responsiveness to user- and cell-triggered changes in mechanics, degradation, and bioactivity. These smart bioinks will capture dynamic changes happening in the ECM during tissue development, disease, and healing processes. This project will utilize these bioinks to investigate temporal contributions of developmentally relevant cell-matrix and cell-cell interactions to instruct stem cells spatially to regenerate osteochondral (OC) interface. The three objectives of the proposed research are: 1) to synthesize novel functional bioinks with tunable printability, stiffness, and degradation; 2) to tailor pendant-chain chemistry for cell-triggered temporal control of bioactivity to enhance stem cell chondrogenesis; and 3) to investigate the ability of smart bioinks to fabricate heterogenous constructs for regeneration of osteochondral interface. The proposed educational plan includes: 1) developing customized research projects for undergraduate students from NJIT and other universities; 2) engaging high school students, from selected local schools with low income and underrepresented student population, in hands-on research experience and providing long-term mentorship; 3) creating a bioprinting class module with hands-on laboratory component; 4) enhancing accessibility of STEM education for blind and visually impaired students.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.