Hierarchical Composite Constructs as Tissue Engineering Scaffolds

作为组织工程支架的分层复合结构

• 批准号: 8878442
• 负责人: Amy Yousefi
• 金额: $ 38.15万
• 依托单位: MIAMI UNIVERSITY OXFORD
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8878442
• 关键词: Alkaline Phosphatase; Allografting; Architecture; Autologous Transplantation; Biochemical; Biological Assay; Biomedical Engineering; Bone Matrix; Bone Regeneration; Bone Tissue; Bone Transplantation; Cell Adhesion; Cell Culture Techniques; Cell-Matrix Junction; Cells; Clinical; DNA; Defect; Deposition; Development; Differentiation Antigens; Dioxanes; Environment; Excision; Fracture; Future; Glycolates; Hematopoiesis; Histology; Human; Hybrids; Hydroxyapatites; In Vitro; Individual; Lead; Mechanics; Mesenchymal Stem Cells; Metabolic; Metabolism; Monitor; Morphology; Mus; Nutrient; Operative Surgical Procedures; Osteogenesis; Outcome; Oxygen; Phase; Polyethylene Glycols; Process; Property; Shapes; Solid; Techniques; Testing; Tissue Engineering; Tissues; Transplantation; Work; base; bone; bone cell; cell growth; cell motility; clinically relevant; cost; design; implantation; improved; internal control; nano; nanocomposite; nanoparticle; novel strategies; osteochondral tissue; osteogenic; oxygen transport; poly(lactic acid); public health relevance; repaired; research study; scaffold; self-renewal; tomography; trend

 DESCRIPTION: Every year, more than 1 million surgical procedures involving the partial excision of bone, bone grafting and fracture repair are performed in the USA, at an estimated cost of more than $5 billion. Well-established clinical approaches are restricted to autograft and allograft transplantation. However, they are limited in access and availability and associated with complications, including graft devitalization and subsequent resorption. As an alternative, tissue engineering using 3D scaffolds may have a huge impact in the future in the repair of bone defects. Developing clinically-relevant bioengineered bone involves challenges in terms of mass transport requirements due to high metabolic activity of bone cells. We have shown that macro/microporous scaffolds produced by a hybrid 3D-bioplotting/porogen-leaching technique can enhance cell ingrowth and produce bone tissue capable of supporting hematopoiesis as well as long term self-renewal of mesenchymal stem cells (MSCs) after implantation in mice. In this work, we are proposing a hybrid 3D-bioplotting/thermally induced phase separation (TIPS) technique. The orthogonally-interconnected channels produced by 3D-bioplotting can provide an ideal environment to guide bone ingrowth. The matrix surrounding these channels will be composed of micropores generated by the TIPS technique, where the pore size and pore morphology can be controlled by manipulating the process parameters and scaffold composition. We have demonstrated the potential of this technique for producing scaffolds made of poly (lactic-co-glycolic acid) (PLGA). Since bone is largely composed of hydroxyapatite (HA), we will perform a design of experiments (DOE) to investigate the effect of HA nanoparticles (nHA) and scaffold architecture on in vitro bone ingrowth and mechanical properties of these scaffolds. This study will test the hypothesis that the hierarchical composite scaffolds will enhance osteogenic differentiation of human MSCs and bone formation through the following specific aims: Aim 1. Develop hierarchical PLGA/nHA constructs as scaffolds for bone tissue engineering. Hypothesis: The hybrid 3D-bioplotting/TIPS will allow designing hierarchical PLGA/nHA scaffolds with the target mechanical properties (modulus > 5 MPa), whereas the DOE will lead to optimal scaffold topologies. Outcome: These scaffolds will offer a highly controlled internal architecture, with orthogonal channels surrounded by a microporous matrix, while the presence of nHA will improve the mechanical properties. Aim 2. Evaluate and monitor the cellular metabolism during in vitro cell growth within the scaffolds. Hypothesis: The new scaffolds will combine the benefits of improved cell migration and oxygen/nutrient transport, while providing a bone-mimicking matrix to enhance cell adhesion (over 50% of the seeded cells) (r) and bone matrix deposition (at least 20% increase compared to CellCeram commercial scaffolds). Approach: Human MSCs will be seeded on the scaffolds and cultured under static and dynamic conditions in media that will induce osteogenic differentiation. Cell attachment, viability, proliferation, and differentiation will be determined for up to 8 weeks based on DNA quantification, alkaline phosphatase (ALP) activity, bone differentiation markers, and microcomputed tomography (uCT).

 产品说明：每年，在美国进行超过100万例涉及骨部分切除、骨移植和骨折修复的外科手术，估计花费超过50亿美元。成熟的临床方法仅限于自体移植和同种异体移植。然而，它们在进入和可用性方面受到限制，并且与并发症相关，包括移植物失活和随后的再吸收。作为一种替代方案，使用3D支架的组织工程可能在未来的骨缺损修复中产生巨大的影响。由于骨细胞的高代谢活性，开发临床相关的生物工程骨涉及质量运输要求方面的挑战。我们已经证明，通过混合3D生物绘图/致孔剂浸出技术生产的大/微孔支架可以增强细胞向内生长，并产生能够支持造血的骨组织，以及植入小鼠后间充质干细胞（MSC）的长期自我更新。在这项工作中，我们提出了一种混合3D生物绘图/热诱导相分离（TIPS）技术。通过3D生物绘图产生的正交互连通道可以提供理想的环境来引导骨长入。这些通道周围的基质将由TIPS技术产生的微孔组成，其中孔径和孔形态可以通过操纵工艺参数和支架组成来控制。我们已经证明了这种技术用于生产由聚（乳酸-共-乙醇酸）（PLGA）制成的支架的潜力。由于骨主要由羟基磷灰石（HA）组成，我们将进行实验设计（DOE），以研究HA纳米颗粒（nHA）和支架结构对体外骨长入和这些支架的机械性能的影响。本研究将通过以下具体目标来验证分级复合支架将增强人MSC的成骨分化和骨形成的假设：目的1。开发可作为骨组织工程支架材料的PLGA/nHA结构。假设：混合3D生物绘图/TIPS将允许设计具有目标机械性能（模量> 5 MPa）的分级PLGA/nHA支架，而DOE将导致最佳支架拓扑结构。结果：这些支架将提供高度受控的内部结构，其中正交通道被微孔基质包围，而nHA的存在将改善机械性能。目标二。评估和监测支架内体外细胞生长过程中的细胞代谢。假设：新的支架将结合联合收割机改善细胞迁移和氧气/营养运输的好处，同时提供骨模拟基质，以增强细胞粘附（超过50%的接种细胞）（r）和骨基质沉积（与CellCeram商业支架相比至少增加20%）。方法：将人MSC接种在支架上，并在诱导成骨分化的培养基中在静态和动态条件下培养。基于DNA定量、碱性磷酸酶（ALP）活性、骨分化标志物和显微计算机断层扫描（uCT），确定细胞附着、活力、增殖和分化长达8周。

项目成果

In vitro characterization of hierarchical 3D scaffolds produced by combining additive manufacturing and thermally induced phase separation.

• DOI: 10.1080/09205063.2020.1841535
• 发表时间: 2021-03
• 期刊: Journal of biomaterials science. Polymer edition
• 作者: Yousefi AM;Powers J;Sampson K;Wood K;Gadola C;Zhang J;James PF
• 通讯作者: James PF

I-Optimal Design of Hierarchical 3D Scaffolds Produced by Combining Additive Manufacturing and Thermally Induced Phase Separation.

• DOI: 10.1021/acsabm.8b00534
• 发表时间: 2018-12
• 期刊: ACS applied bio materials
• 影响因子: 4.7
• 作者: A. Yousefi;Junyi Liu;Riley Sheppard;S. Koo;J. Silverstein;Jing Zhang;P. James