Lara-Padilla Hernan, Mendoza-Buenrostro Christian, Cardenas Diego, Rodriguez-Garcia Aida, Rodriguez Ciro A
Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Monterrey 64849, Mexico.
Departamento de Ciencias de la Energía y Mecánica, Universidad de las Fuerzas Armadas ESPE, Sangolquí 171-5-231B, Ecuador.
Materials (Basel). 2017 Jun 11;10(6):640. doi: 10.3390/ma10060640.
The combination of different materials and capabilities to manufacture at several scales open new possibilities in scaffold design for bone regeneration. This work is focused on bimodal scaffolds that combine polylactic acid (PLA) melt extruded strands with polycaprolactone (PCL) electrospun fibers. This type of bimodal scaffold offers better mechanical properties, compared to the use of PCL for the extruded strands, and provides potential a means for controlled drug and/or growth factor delivery through the electrospun fibers. The technologies of fused deposition modeling (FDM) and electrospinning were combined to create 3D bimodal constructs. The system uses a controlled cooling system allowing the combination of polymers with different melting temperatures to generate integrated scaffold architecture. The thermoplastic polymers used in the FDM process enhance the mechanical properties of the bimodal scaffold and control the pore structure. Integrated layers of electrospun microfibers induce an increase of the surface area for cell culture purposes, as well as potential in situ controlled drug and/or growth factor delivery. The proposed bimodal scaffolds (PLA extruded strands and PCL electrospun fibers) show appropriate morphology and better mechanical properties when compared to the use of PCL extruded strands. On average, bimodal scaffolds with overall dimensions of 30 × 30 × 2.4 mm³ (strand diameter of 0.5 mm, strand stepover of 2.5 mm, pore size of 2 mm, and layer height of 0.3 mm) showed scaffold stiffness of 23.73 MPa and compression strength of 3.85 MPa. A cytotoxicity assay based human fibroblasts showed viability of the scaffold materials.
不同材料的组合以及在多个尺度上进行制造的能力为骨再生支架设计开辟了新的可能性。这项工作聚焦于将聚乳酸（PLA）熔体挤出股线与聚己内酯（PCL）电纺纤维相结合的双峰支架。与仅使用PCL进行挤出股线相比，这种类型的双峰支架具有更好的机械性能，并且通过电纺纤维提供了一种潜在的可控药物和/或生长因子递送方式。熔融沉积建模（FDM）技术和电纺技术相结合，创建了三维双峰结构。该系统使用受控冷却系统，允许将具有不同熔化温度的聚合物组合在一起，以生成集成的支架结构。FDM过程中使用的热塑性聚合物增强了双峰支架的机械性能并控制了孔隙结构。电纺微纤维的集成层增加了用于细胞培养目的的表面积，以及潜在的原位可控药物和/或生长因子递送。与使用PCL挤出股线相比，所提出的双峰支架（PLA挤出股线和PCL电纺纤维）显示出合适的形态和更好的机械性能。平均而言，总体尺寸为30×30×2.4mm³（股线直径0.5mm，股线步距2.5mm，孔径2mm，层高度0.3mm）的双峰支架显示出23.73MPa的支架刚度和3.85MPa的抗压强度。基于人成纤维细胞的细胞毒性试验表明了支架材料的活力。
