RAPID PROTOTYPING OF POLYMERIC MEDICAL DEVICES

高分子医疗器械的快速原型制作

• 批准号: 5210062
• 负责人: BENJAMIN M WU
• 金额: --
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/5210062
• 关键词: biomaterial development /preparation; biomedical automation; copolymer; dental materials; polymers; surface property

Three dimensional printing (3DP) offers precise control over macroscopic geometry and spatial distribution of multiple materials according to computerized 3D models. 3DP can also affect local composition and microstructure, and offer many new possibilities for the fabrication of biomedical devices. The ability to control microstructure is critical for drug delivery devices and tissue engineering matrices. The precise control of microstructure, however, requires a better understanding of the relationship between the material properties and processing variables. The proposed work focuses on identifying the critical parameters for controlling microstructure in 3DP polymeric parts. The ability to produce dense microstructure is critical in the fabrication of polymeric drug delivery devices. Preliminary results suggest that the ability to obtain dense microstructure is dependent on the powder material used, which is highly dependent on the purpose of drug delivery device. Oral dosage forms can be fabricated with pharmaceutical grade excipient powder and latex. The powder-binder interaction for this material combination is similar to that observed in conventional 3DP of ceramic (and stainless steel) parts, where loose ceramic particles are coated and gelled together by a polymer colloidal binder. The density of the typical pre-fired 3DP ceramic part is only on the order of 45-55o. Many of the post-processing techniques for industrial parts are inappropriate for the biomedical materials. Dense polymeric structures must, therefore, be obtained during printing. No previous work has been done on creating highly dense green parts directly by printing binder into porous powder bed. Implantable devices are designed to deliver drugs for months to years, and are typically constructed with bioerodable polymer powder and organic solvents. The powder-binder interaction for this material combination is unlike any other observed phenomena in 3DP. The neighboring polymeric particles are dissolved and joined together by the binder droplets. Oral and implantable devices with simple shapes will be fabricated with different combinations of 3DP processing variables, powder, and binder compositions. The devices will be sectioned and analyzed for density, and the results will be compared for various processing conditions. Physical models will be proposed to describe the critical phenomena which are responsible for the formation of dense structures for various materials systems. Real devices for oral delivery and implantation will be designed and constructed with 3DP, and device performance will be assessed by drug release profiles. Computer models will be proposed to model the release characteristics of the real devices. The second objective is to fabricate polymeric tissue engineering devices with controlled porosity. Tissue engineering devices are porous structures which act as scaffolds for guided tissue regeneration. The ability to preferentially promote cell adhesion and migration is accomplished by directing nutrient delivery in a complex, porous cell seeding structure. Experiments will be conducted to investigate various 3DP strategies to control channel dimensions (width and length), surface microporosity, and distribution of cell-matrix adhesion modifiers. The goal of the investigation is to determine the effects of these parameters on cell adhesion. The fundamental understanding of the relationship between material properties, 3DP variables, microstructure, and device performance will have real implications for device design and fabrication strategy of all future 3DP polymeric medical devices.

三维打印(3DP)提供精确控制 多材料的超宏观几何与空间分布 根据计算机化的3D模型。3DP也会影响当地 成分和微观结构，并为 生物医学装置的制造。控制微观结构的能力 是药物输送装置和组织工程基质的关键。 然而，对微观结构的精确控制需要更好的 对材料性能与材料性能之间关系的理解 正在处理变量。拟议的工作重点是确定 控制3DP聚合物零件微观结构的关键参数。 在制造中，产生致密微结构的能力是至关重要的 聚合物药物输送装置。初步结果显示， 获得致密微结构的能力取决于粉末材料 使用，这高度依赖于药物输送装置的目的。 口服剂型可用药用级辅料制成 粉末和乳胶。该材料的粉末-粘结剂相互作用 结合类似于在传统的陶瓷3DP中观察到的 (和不锈钢)零件，其中松散的陶瓷颗粒被涂覆和 由聚合物胶体粘合剂粘合在一起。典型人群的密度 预烧的3DP陶瓷部分只有45-55o的量级。许多人 工业零件的后处理技术不适合于 生物医学材料。因此，致密的聚合物结构必须是 在打印过程中获得。以前没有做过关于创建 将粘结剂直接打印到多孔粉中的高密度坯件 床。植入式设备的设计是为了将药物输送到 几年，通常用可生物识别的聚合物粉末和 有机溶剂。该材料的粉末-粘结剂相互作用 组合不同于在3DP中观察到的任何其他现象。这个 相邻的聚合物颗粒被溶解并通过 粘合剂液滴。形状简单的口腔和植入型设备将是 用3DP加工变量的不同组合制造， 粉末和粘结剂组合物。这些设备将被分段并 对密度进行分析，并将结果与不同 加工条件。将提出物理模型来描述 导致致密物质形成的临界现象 各种材料系统的结构。真正的口腔递送设备 植入将用3DP设计和建造，并装置 性能将通过药物释放情况进行评估。计算机模型 将建议对真实设备的释放特性进行建模。 第二个目标是制造聚合物组织工程设备 具有可控的孔隙度。组织工程设备是多孔性的 作为引导组织再生的支架的结构。这个 优先促进细胞黏附和迁移的能力是 通过在复杂的、多孔的细胞中引导营养输送来完成的 播种结构。将进行实验以调查各种不同的 控制渠道尺寸(宽度和长度)、表面的3DP策略 微孔率和细胞-基质黏附改性剂的分布。这个 调查的目标是确定这些参数的影响 关于细胞黏附的。对两国关系的基本认识 材料特性、3DP变量、微观结构和器件之间的关系 性能将对器件设计和制造产生实际影响 未来所有3DP聚合物医疗器械的战略。