Optomechanical-organized multipulse dynamics in ultrafast fiber laser

A novel organized multipulse pattern and its birth dynamics under strong optomechanical effect in microfiber-assisted ultrafast fiber laser are investigated in this work.The background pulses are observed to obviously exhibit selectively amplifying self-organized process of evolving into quasi-stable equidistant clusters.The radio frequency spectrum of the multipulse pattern displays a harmonic mode-locking-like behavior with a repetition rate of 2.0138 GHz,corresponding to the frequency of torsional-radial(TR_(2m))acoustic mode in microfiber.The results show the evidence of optomechanical effect in dominating the birth dynamics and pattern of multipulse.

3D printed collagen/silk fibroin scaffolds carrying the secretome of human umbilical mesenchymal stemcells ameliorated neurological dysfunction after spinal cord injury in rats

Although implantation of biomaterials carrying mesenchymal stem cells(MSCs)is considered as a promising strategy for ameliorating neural function after spinal cord injury(SCI),there are still some challenges including poor cell survival rate,tumorigenicity and ethics concerns.The performance of the secretome derived from MSCs was more stable,and its clinical transformation was more operable.Cytokine antibody array demonstrated that the secretome of MSCs contained 79 proteins among the 174 proteins analyzed.Three-dimensional(3D)printed collagen/silk fibroin scaffolds carrying MSCs secretome improved hindlimb locomotor function according to the Basso–Beattie–Bresnahan scores,the inclined-grid climbing test and electrophysiological analysis.Parallel with locomotor function recovery,3D printed collagen/silk fibroin scaffolds carrying MSCs secretome could further facilitate nerve fiber regeneration,enhance remyelination and accelerate the establishment of synaptic connections at the injury site compared to 3D printed collagen/silk fibroin scaffolds alone group according to magnetic resonance imaging,diffusion tensor imaging,hematoxylin and eosin staining,Bielschowsky’s silver staining,immunofluorescence staining and transmission electron microscopy.These results indicated the implantation of 3D printed collagen/silk fibroin scaffolds carrying MSCs secretome might be a potential treatment for SCI.

Integrated printed BDNF/collagen/chitosan scaffolds with low temperature extrusion 3D printer accelerated neural regeneration after spinal cord injury

Recent studies have shown that 3D printed scaffolds integrated with growth factors can guide the growth of neurites and promote axon regeneration at the injury site.However,heat,organic solvents or cross-linking agents used in conventional 3D printing reduce the biological activity of growth factors.Low temperature 3D printing can incorporate growth factors into the scaffold and maintain their biological activity.In this study,we developed a collagen/chitosan scaffold integrated with brain-derived neurotrophic factor(3D-CC-BDNF)by low temperature extrusion 3D printing as a new type of artificial controlled release system,which could prolong the release of BDNF for the treatment of spinal cord injury(SCI).Eight weeks after the implantation of scaffolds in the transected lesion of T10 of the spinal cord,3D-CC-BDNF significantly ameliorate locomotor function of the rats.Consistent with the recovery of locomotor function,3D-CC-BDNF treatment could fill the gap,facilitate nerve fiber regeneration,accelerate the establishment of synaptic connections and enhance remyelination at the injury site.