Dental Stem Cells and Tooth Tissue Engineering

描述（由申请人提供）：本研究项目的最终目标是开发新的基于生物学的人类牙齿和颅面骨骼修复和再生疗法。我们假设，提高知识的牙齿干细胞（DSC）的性质和特点，结合组织工程策略的改进知识，可靠地产生矿化的牙齿和颅面组织的可预测的大小和形状，将导致开发新的和有效的，临床相关的治疗人类。为了解决这一假设，提出了四个具体的目标，所有这些目标都将专门使用从提取的人类牙齿中获取的人类DSCs。首先，我们将表征单独采集的人牙组织的特性，以建立DSC特性的正常范围，将DSC特性与供体的年龄和整体健康状况相关联，并将这些特性与成功使用采集的牙干细胞进行牙组织再生治疗的能力相关联。接下来，我们将测试四种不同的支架材料，这些材料是根据其定义的物理特性精心挑选的，它们能够产生可预测大小和形状的生物工程人类牙冠。第三，我们将扩展我们的研究结果，证明丝支架可用于产生预测大小和形状的骨牙本质，以生物工程化全尺寸，功能性人类牙根等同物，可以支持合成或生物工程牙冠。将系统地评价丝支架的制造方法、孔隙率、降解速率和添加的生长因子肽。根据之前审查的建议，将在皮下和小型猪下颌骨种植体模型中执行目标2和3。最后，在目标4中，我们将联合收割机结合我们的牙冠、牙根和颅面骨骼再生策略，再次使用尤卡坦小型猪下颌种植体模型，生成连续的第1、第2和第3代替换牙齿。对于每一个拟议的目标，将进行详细的生物工程牙种植体组织的发育分析，以更好地理解，并制定策略，以改善牙组织再生。 我们使用人类DSCs和最先进的支架进行牙齿修复和再生的新方法 结合我们在发育生物学和组织方面的广泛专业知识， 工程，有可能提供新的和改进的，基于生物学的修复和再生策略，使用自体组织。拟议研究的成功完成将极大地改变目前存在的牙科领域，将临床相关的牙科修复疗法扩展到包括具有与自然形成的牙齿组织密切匹配的特性的生物基牙科材料。 公共卫生相关性：由于颅面和牙齿组织自我修复的能力严重有限，这些缺陷仍然是影响全球数百万人的重大临床问题，包括儿童和成人。蛀牙、牙周病、颅面先天缺陷、创伤和癌症，都有助于损害口腔健康，并相应地降低整体健康和生活质量。目前，基于合成材料的修复方法或自体移植物（其通常导致供体部位发病）仅用于修复人类颅面骨骼和牙齿缺陷。这里提出的研究将扩展我们以前发表的研究，设计方法来修复和再生颅面骨骼和牙齿缺损，使用生物学为基础的组织工程方法，和人类牙齿干细胞。我们预计，成功开发的替代生物为基础的组织修复方法将提供显着改善个人需要修复/再生颅面骨骼和牙齿缺损的治疗。

DESCRIPTION (provided by applicant): The ultimate goal of this research project is to develop novel biologically based, dental and craniofacial skeletal repair and regeneration therapies in humans. We hypothesize that improved knowledge of dental stem cell (DSC) properties, and characteristics, combined with improved knowledge of tissue engineering strategies to reliably generate mineralized dental and craniofacial tissues of predictable size and shape, will result in the development of novel and effective, clinically relevant therapies for humans. To address this hypothesis, four specific aims are proposed, all of which will exclusively use human DSCs harvested from extracted human teeth. First, we will characterize the properties of individually harvested human dental tissues, to establish the normal range of DSC properties, to correlate DSC properties with the age and overall health of the donor, and to correlate these properties with the ability to successfully use harvested dental stem cells for dental tissue regeneration therapies. Next, we will test four different scaffold materials, carefully chosen for their defined physical properties, for their ability to generate bioengineered human tooth crowns of predictable size and shape. Third, we will expand upon our results demonstrating that silk scaffolds can be used to generate osteodentin of predicted size and shape, to bioengineer full sized, functional human tooth root equivalents that can support a synthetic or bioengineered tooth crown. Silk scaffold fabrication methods, porosity, degradation rates, and added growth factor peptides, will be systematically evaluated. As recommended in prior review, Aims 2 and 3 will be performed in both subcutaneous and minipig mandibular implant models. Finally, in Aim 4, we will combine our tooth crown, root, and craniofacial skeletal regenerative strategies, again using the Yucatan mini pig mandibular implant model, to generate successive 1st, 2nd and 3rd generation replacement teeth. For each of the proposed aims, detailed developmental analyses of bioengineered dental implant tissues will be performed in order to better understand, and devise strategies to improve dental tissue regeneration. Our novel approach to tooth repair and regeneration, using human DSCs, and state of the art scaffold fabrication methods, combined with our extensive expertise in Developmental Biology and Tissue Engineering, have the potential to provide new and improved, biologically based repair and regeneration strategies, using autologous tissues. The successful accomplishment of the proposed studies would dramatically alter the field of dentistry as it currently exists, extending clinically relevant dental repair therapies to include biologically based dental materials with properties closely matching those of naturally formed dental tissues. PUBLIC HEALTH RELEVANCE: Due to the severely limited ability for craniofacial and dental tissues to repair themselves, these defects remain a significant clinical problem that affects millions of people worldwide, including both children and adults. Tooth decay, periodontal disease, craniofacial birth defects, trauma, and cancer, all contribute to compromised oral health, and correspondingly to reduced overall health and quality of life. At the present time, synthetic material based repair methods, or autologous grafts which often result in donor site morbidity, are exclusively being used to repair human craniofacial skeletal and tooth defects. The studies proposed here will expand on our prior published studies, to devise methods to repair and regenerate craniofacial skeletal and tooth defects using biologically based tissue engineering approaches, and human dental stem cells. We anticipate that the successful development of alternative biologically based tissue repair methods will provide significantly improved therapies for individuals requiring repair/regeneration of craniofacial skeletal and tooth defects.