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Electrospinning is a versatile and convenient technology to generate nanofibers suitable for tissue engineering. However, the low production rate of traditional needle electrospinning hinders its applications. Needleless electrospinning is a potential strategy to promote the application of electrospun nanofiber in various fields. In this study, disc-electrospinning (one kind of needleless electrospinning) was conducted to produce poly(ε-caprolactone)/gelatin (PCL/GT) scaffolds of different structure, namely the nanoscale structure constructed by nanofiber and multiscale structure consisting of nanofiber and microfiber. It was found that, due to the inhomogeneity of PCL/GT solution, disc-electrospun PCL-GT scaffold presented multiscale structure with larger pores than that of the acid assisted one (PCL-GT-A). Scanning electron microscopy images indicated the PCL-GT scaffold was constructed by nanofibers and microfibers. Mouse fibroblasts and rat bone marrow stromal cells both showed higher proliferation rates on multiscale scaffold than nanoscale scaffolds. It was proposed that the nanofibers bridged between the microfibers enhanced cell adhesion and spreading, while the large pores on the three dimensional (3D) PCL-GT scaffold provide more effective space for cells to proliferate and migrate. However, the uniform nanofibers and densely packed structure in PCL-GT-A scaffold limited the cells on the surface. This study demonstrated the potential of disc-electrospun PCL-GT scaffold containing nanofiber and microfiber for 3D tissue regeneration. [ABSTRACT FROM AUTHOR]

Fabrication of 3D scaffold to mimic the nanofibrous structure of the nature extracellular matrix (ECM) with appropriate mechanical properties and excellent biocompatibility, remain an important technical challenge in tissue engineering. The present study reports the strategy to fabricate a 3D nanofibrous scaffold with similar structure to collagen in ECM by combining electrospinning and freeze-drying technique. With the technique reported here, a nanofibrous structure scaffold with hydrophilic and superabsorbent properties can be readily prepared by Gelatin and Polylactic acid (PLA). In wet state the scaffold also shows a super-elastic property, which could bear a compressive strain as high as 80% and recovers its original shape afterwards. Moreover, after 6 days of culture, L-929 cells grow, proliferate and infiltrated into the scaffold. The results suggest that this 3D nanofibrous scaffold would be promising for varied field of tissue engineering application. [ABSTRACT FROM AUTHOR]

Silk fibroin (SF)/PEO nanofibers prepared by green electrospinning is safe, non-toxic and environment friendly, it is a potential drug delivery carrier for tissue engineering. In this study, a core–shell nanofibers named as Dex@SF/PEO were obtained by green electrospinning with SF/PEO as the shell and dexamethasone (Dex) in the core. The nanofiber morphology and core–shell structure were studied by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The Dex release behavior from the nanofibers was tested by High Performance liquid (HPLC) method. The protective effect of drug loaded nanofibers mats on Porcine hip artery endothelial cells (PIECs) against LPS-induced inflammatory damage were determined by MTT assay. TEM result showed the distinct core–shell structure of nanofibers. In vitro drug release studies demonstrated that dexamethasone can sustain release over 192 h and core–shell nanofibers showed more slow release of Dex compared with the blending electrospinning nanofibers. Anti-inflammatory activity in vitro showed that released Dex can reduce the PIECs inflammatory damage and apoptosis which induced by lipopolysaccharide (LPS). Dex@SF/PEO nanofibers are safe and non-toxic because of no harmful organic solvents used in the preparation, it is a promising environment friendly drug carrier for tissue engineering. [ABSTRACT FROM AUTHOR]

An electrospun-aligned nanoyarn-reinforced nanofibrous scaffold (NRS) was developed for tendon tissue engineering to improve mechanical strength and cell infiltration. The novel scaffold composed of aligned nanoyarns and random nanofibers was fabricated via electrospinning using a two-collector system. The aim of the present study was to investigate three different types of electrospun scaffolds (random nanofibrous scaffold, aligned nanofibrous scaffold and NRS) based on silk fibroin (SF) and poly( l -lactide- co -caprolactone) blends. Morphological analysis demonstrated that the NRS composed of aligned nanoyarns and randomly distributed nanofibers formed a 3D microstructure with relatively large pore sizes and high porosity. Biocompatibility analysis revealed that bone marrow-derived mesenchymal stem cells exhibited a higher proliferation rate when cultured on the NRS compared with the other scaffolds. The mechanical testing results indicated that the tensile properties of the NRS were reinforced in the direction parallel to the nanoyarns and satisfied the mechanical requirements for tendon repair. In addition, cell infiltration was significantly enhanced on the NRS. In conclusion, with its improved porosity and appropriate mechanical properties, the developed NRS shows promise for tendon tissue engineering applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Tissue scaffolds with three-dimensional (3D) nanofibrous biomimetic structures have attracted attention in the field of bone regeneration. In recent years, emerging strategies based on electrospinning technologies have facilitated the preparation of 3D nanofibrous scaffolds. Based on these developments, in this study, 3D scaffolds possessing both nanofibrous morphologies and interconnected pores were fabricated for their potential in bone tissue engineering. By combining homogenizing, freeze-drying, and thermal crosslinking techniques, nano-hydroxyapatite/PLLA/gelatin (nHA/PLA/GEL) 3D nanofibrous scaffolds were prepared using pre-fabricated electrospun nanofibers. Then, utilizing a polydopamine (pDA)-assisted coating strategy, bone morphogenetic protein-2 (BMP-2)-derived peptides were further immobilized onto the 3D scaffolds to obtain the resulting nano-hydroxyapatite/PLLA/gelatin-peptide (nHA/PLA/GEL-PEP) 3D nanofibrous scaffolds capable of sustained release. Bone mesenchymal stem cells (BMSCs) were cultured on the 3D nanofibrous scaffolds, then relative cell viability, alkaline phosphatase (ALP) activity, and gene expression assays were performed to study the effects of the scaffolds on cell growth and osteogenic differentiation in vitro. Furthermore, the ability of bone formation in vivo was evaluated using a rat cranial bone defect model. In vitro and in vivo results demonstrated that the 3D nanofibrous scaffolds incorporated with nHA and BMP-2 peptides exhibited favorable biocompatibility and osteoinductivity. Therefore, these nanofibrous scaffolds have excellent potential in bone regenerative medicine. [ABSTRACT FROM AUTHOR]

Electrospinning has been widely used in fabrication of tissue engineering scaffolds. Currently, most of the electrospun nanofibers performed like a conventional two-dimensional (2D) membrane, which hindered their further applications. Moreover, the low production rate of the traditional needle-electrospinning (NE) also limited the commercialization. In this article, disc-electrospinning (DE) was utilized to fabricate a three-dimensional (3D) scaffold consisting of porous macro/nanoscale fibers. The morphology of the porous structure was investigated by scanning electron microscopy images, which showed irregular pores of nanoscale spreading on the surface of DE polycaprolactone (PCL) fibers. Protein adsorption assessment illustrated the porous structure could significantly enhance proteins pickup, which was 55% higher than that of solid fiber scaffolds. Fibroblasts were cultured on the scaffold. The results demonstrated that DE fiber scaffold could enhance initial cell attachment. In the 7 days of culture, fibroblasts grew faster on DE fiber scaffold in comparison with solid fiber, solvent cast (SC) film and TCP. Fibroblasts on DE fibers showed a stretched shape and integrated with the porous surface tightly. Cells were also found to migrate into the DE scaffold up to 800 μm. Results supported the use of DE PCL fibers as a 3D tissue engineering scaffold in soft tissue regeneration. [ABSTRACT FROM AUTHOR]