Embedding aligned nanofibrous architectures within 3D-printed polycaprolactone scaffolds for directed cellular infiltration and tissue regeneration

Abstract

Three-dimensional (3D) printing provides a promising way to fabricate biodegradable scaffolds with designer architectures for the regeneration of various tissue. However, the existing 3D-printed scaffolds commonly suffer from weak cell-scaffold interactions and insufficient cell organizations due to the limited resolution of the 3D-printed features. Here, composite scaffolds with mechanically-robust frameworks and aligned nanofibrous architectures are presented and hybrid manufactured by combining techniques of 3D printing, electrospinning, and unidirectional freeze-casting. It was found that the composite scaffolds provided volume-stable environments and enabled directed cellular infiltration for tissue regeneration. In particular, the nanofibrous architectures with aligned micropores served as artificial extracellular matrices and improved the attachment, proliferation, and infiltration of cells. The proposed scaffolds can also support adipogenic maturation of adipose-derived stem cells (ADSCs) in vitro. Moreover, the composite scaffolds were found to guide directed tissue infiltration and promote nearby neovascularization when implanted into a subcutaneous model of rats, and the addition of ADSCs further enhanced their adipogenic potential. The presented hybrid manufacturing strategy might provide a promising way to produce additional topological cues in 3D-printed scaffolds for better tissue regeneration.

3D printed grafts with gradient structures for organized vascular regeneration

“…Further enhancement of mechanical properties of the 3D-printed grafts are requisite for clinical translation of the grafts. To enhance the mechanical properties of the vascular grafts, introduction of nanosystem into 3D-printed vascular grafts is an option, since nanosystem can improve load transfer efficiency in the grafts [58][59][60][61][62]. Another option is to enhance the mechanical properties of 3D printed vascular grafts by electrospinning PCL sheaths in the outermost of the vascular grafts.…”

High-throughput microfluidic production of carbon capture microcapsules: fundamentals, applications, and perspectives

“…The use of 3D printing has gained popularity in recent years as a technique for directly fabricating 3D structures in a single step [84][85][86]. The 3D geometric information is stored in a graphic program file and automatically processed by a computer-controlled printer system, enabling accurate and high-resolution fabrication with low time consumption and cost.…”

Hierarchically structured biomaterials for tissue regeneration

“…The integrated functionality of hierarchical structure in improving cell behaviors should be emphasized because they can provide more structural characteristics, which are conducive to the comprehensive regulation of a series of cell behaviors [121] . For example, a micro/nano-hierarchical scaffold was constructed by incorporating arranged micro/nanofibers into layered scaffolds [122] . The design of this hierarchical structure significantly improved the proliferation and arrangement of myoblasts and even promoted the formation of myotubes.…”

“…To address the limitations of current hierarchically structured biomaterials, several aspects should be considered. Firstly, the design of biomimetic hierarchical structures Osteochondral tissue [76,[151][152] ; tendon-bone [155] Freeze-drying Improve mechanical properties; control cell arrangement and differentiation Periodontium [111] 3D printing Provide structure and function similar to native tissues Trachea [161][162][163] ; cornea [171] Multi-layered scaffolds Cast molding Guide cell arrangement; improve cell metabolism and matrix anabolism Annulus fibrosus [138] Electrospinning Mimic the structure of native tissue; improve mechanical and bioactivity Temporomandibular joint disc [45] 3D printing Mimic the structure of native tissue; regulate cellcell interactions Bone [144][145]147,150] ; flat bone [136] Electrospinning and 3D printing Mimic the structure of native tissue; guide cell alignment and differentiation Myocardium [49] ; skeletal muscle tissue [122] ; adipo tissue [123] Scaffolds with integrated units Freeze-drying and cast molding Improve perfusion properties and neurogenesis; direct the growth of neotissues Peripheral nerve [57,128] Electrospinning Mimic the structure of native tissue; improve mechanical strength; enhance cell bioactivity Bone [48,132] ; skin [159] 3D printing Mimic the structure of native tissue; enhance cell bioactivity Osteochondral regeneration [59] ; bone [119,127,130] Electrospinning and 3D printing Mimic the structure of native tissue; guide cell arrangement Myocardium [168] Freezing drying Improve mechanical performance and angiogenesis Soft gingival tissue [58] Scaffolds with varying length scales…”