Culbreath Clayton J, McCullen Seth D, Mefford O Thompson
Poly-Med, Inc. Anderson, South Carolina 29625, United States.
Department of Materials Science and Engineering, Clemson University, Clemson, South Carolina 29634, United States.
ACS Omega. 2024 Aug 20;9(35):36982-36992. doi: 10.1021/acsomega.4c01864. eCollection 2024 Sep 3.
Electrospinning (ES) is a versatile process mode for creating fibrous materials with various structures that have broad applications ranging from regenerative medicine to tissue engineering and surgical mesh implants. The recent commercialization of this technology for implant use has driven the use of resorbable electrospun products. Resorbable electrospun meshes offer great promise as temporary implants that can utilize the layer upon layer method of additive manufacturing to incorporate porosity as a function of process parameters into a scaffold structure. The interconnected porosity and feature size known to ES have previously been observed to hold great potential for simulating the natural cellular environment of soft tissue. This microstructure, proper degradation kinetics, and mechanical properties combine to provide the design basis for artificial tissue structures that could aid in not only wound healing but also true tissue engineering and regenerative medicine. While current advancement in the field is understood to be limited by material properties, the importance of optimizing mechanical properties with currently available materials should not be overlooked. This work investigated the process parameter effects and interactions that control the structure-property relationship for a range of medical-grade aliphatic polyester materials with a range of intrinsic properties. An ε-caprolactone homopolymer (PCL), l-lactide homopolymer (PLLA), and Lactoflex, a copolymer with intermediate properties relative to the homopolymers, were characterized before, during, and after the additive manufacturing process. The interacting effects of process parameters, distance to collector, and dispensing rate were shown to produce variable-density, nonwoven scaffold structures. The resorbable mesh scaffolds of PLLA, PCL, and Lactoflex demonstrated a broad range of mechanical properties (approximately 1-10 MPa ultimate tensile strength and 5-390 MPa tensile modulus). Postprocessing of scaffolds demonstrated removal of solvents and preservation of micrometer-sized features. Resorbable polymers and electrospinning can produce scaffold materials with excellent features and offer tremendous potential in the field of implantable resorbable devices.
静电纺丝（ES）是一种通用的工艺模式，用于制造具有各种结构的纤维材料，这些材料在从再生医学到组织工程和手术网植入物等广泛领域都有应用。该技术最近在植入物领域的商业化推动了可吸收静电纺丝产品的使用。可吸收静电纺丝网作为临时植入物具有很大的潜力，它可以利用增材制造的逐层方法，将孔隙率作为工艺参数的函数纳入支架结构中。静电纺丝已知的相互连接的孔隙率和特征尺寸此前已被观察到在模拟软组织的自然细胞环境方面具有巨大潜力。这种微观结构、适当的降解动力学和机械性能相结合，为人工组织结构提供了设计基础，不仅有助于伤口愈合，还能真正应用于组织工程和再生医学。虽然目前该领域的进展被认为受到材料性能的限制，但利用现有材料优化机械性能的重要性不应被忽视。这项工作研究了一系列具有不同固有性能的医用级脂肪族聚酯材料的工艺参数效应和相互作用，这些效应和相互作用控制着结构 - 性能关系。在增材制造过程之前、期间和之后，对一种ε - 己内酯均聚物（PCL）、l - 丙交酯均聚物（PLLA）以及一种相对于均聚物具有中间性能的共聚物Lactoflex进行了表征。工艺参数、到收集器的距离和分配速率的相互作用效应被证明会产生可变密度的非织造支架结构。PLLA、PCL和Lactoflex的可吸收网支架表现出广泛的机械性能（极限拉伸强度约为1 - 10 MPa，拉伸模量为5 - 390 MPa）。支架的后处理证明了溶剂的去除以及微米级特征的保留。可吸收聚合物和静电纺丝可以生产具有优异特性的支架材料，并在可植入可吸收装置领域提供巨大潜力。
