Effects of ICA on the Proliferation and Secretion of Chondrocytes in Bioscaffold Based on 3D Printing Technology

Articular cartilage plays an important role in weight-bearing and movement.However,it is also more easily damaged in intra-articular fractures.As the cartilage has no vessel and nerve,so it is hardly to repair itself once damaged seriously.Tissue engineering is a potential way to cure the cartilage damage because it combines scaffold and cells.Gels

Supercritical fluid-assisted fabrication of C-doped Co_(3)O_(4) nanoparticles based on polymer-coated metal salt nanoreactors for efficient enzyme-mimicking and glucose sensor properties

Nanomaterials doped with non-metallic C have attracted tremendous attention as potential nano-artificial enzymes due to their ability to change the energy band structure to improve their intrinsic properties.Herein,we report a green,facile,efficient,fast strategy to access high-performance nanozymes via supercritical CO_(2)fluid technology-fabricated polymer nanoreactor of poly-(methyl vinyl ether-co-maleic anhydride)(PVM/MA)coated Co(NO_(3))_(2)into C-doped Co_(3)O_(4)(C-Co_(3)O_(4))nanozyme by a onestep calcination process.Converting PVM/MA to C doping into Co_(3)O_(4)shortens the entire lattice constant of the crystal structure,and the overall valence band energy level below the Fermi level shifts toward the lower energy direction.The as-prepared CCo_(3)O_(4)demonstrated significant peroxidase-like catalytic activity,significantly greater than the undoped Co_(3)O_(4)nanoparticle nanozyme.The following density functional theory(DFT)calculations revealed that the doped nano-enzyme catalytic site displayed a unique electronic structure,altering the material surface with more electrons to fill the anti-bond of the two molecular orbitals,significantly improving the peroxidase-like enzyme catalytic and glucose sensor performance.The resultant enzymatic glucose sensing in a linear range of 0.1–0.6 mM with a detection limit of 3.86μM is in line with standard Michaelis–Menten theory.Collectively,this work demonstrates that converting polymers into nanozymes of C-doped form by supercritical CO_(2)fluid technology in a step is an effective strategy for constructing high-performance glucose sensor nanozymes.This cost-effective,reliable,precise system offers the potential for rapid analyte detection,facilitating its application in a variety of fields.

Supercritical fluid-assisted controllable fabrication of open and highly interconnected porous scaffolds for bone tissue engineering

Recently tremendous progress has been evidenced by the advancements in developing innovative three-dimensional(3 D)scaffolds using various techniques for addressing the autogenous grafting of bone. In this work, we demonstrated the fabrication of porous polycaprolactone(PCL) scaffolds for osteogenic differentiation based on supercritical fluid-assisted hybrid processes of phase inversion and foaming. This eco-friendly process resulted in the highly porous biomimetic scaffolds with open and interconnected architectures. Initially, a 2^3 factorial experiment was designed for investigating the relative significance of various processing parameters and achieving better control over the porosity as well as the compressive mechanical properties of the scaffold. Then, single factor experiment was carried out to understand the effects of various processing parameters on the morphology of scaffolds. On the other hand, we encapsulated a growth factor, i.e., bone morphogenic protein-2(BMP-2), as a model protein in these porous scaffolds for evaluating their osteogenic differentiation. In vitro investigations of growth factor loaded PCL scaffolds using bone marrow stromal cells(BMSCs) have shown that these growth factor-encumbered scaffolds were capable of differentiating the cells over the control experiments. Furthermore, the osteogenic differentiation was confirmed by measuring the cell proliferation, and alkaline phosphatase(ALP) activity, which were significantly higher demonstrating the active bone growth. Together, these results have suggested that the fabrication of growth factor-loaded porous scaffolds prepared by the eco-friendly hybrid processing efficiently promoted the osteogenic differentiation and may have a significant potential in bone tissue engineering.

3D bioprinting of conductive hydrogel for enhanced myogenic differentiation

Recently,hydrogels have gained enormous interest in three-dimensional(3D)bioprinting toward developing functional substitutes for tissue remolding.However,it is highly challenging to transmit electrical signals to cells due to the limited electrical conductivity of the bioprinted hydrogels.Herein,we demonstrate the 3D bioprinting-assisted fabrication of a conductive hydrogel scaffold based on poly-3,4-ethylene dioxythiophene(PEDOT)nanoparticles(NPs)deposited in gelatin methacryloyl(GelMA)for enhanced myogenic differentiation of mouse myoblasts(C2C12 cells).Initially,PEDOT NPs are dispersed in the hydrogel uniformly to enhance the conductive property of the hydrogel scaffold.Notably,the incorporated PEDOT NPs showed minimal influence on the printing ability of GelMA.Then,C2C12 cells are successfully encapsulated within GelMA/PEDOT conductive hydrogels using 3D extrusion bioprinting.Furthermore,the proliferation,migration and differentiation efficacies of C2C12 cells in the highly conductive GelMA/PEDOT composite scaffolds are demonstrated using various in vitro investigations of live/dead staining,F-actin staining,desmin and myogenin immunofluorescence staining.Finally,the effects of electrical signals on the stimulation of the scaffolds are investigated toward the myogenic differentiation of C2C12 cells and the formation of myotubes in vitro.Collectively,our findings demonstrate that the fabrication of the conductive hydrogels provides a feasible approach for the encapsulation of cells and the regeneration of the muscle tissue.

Synergistic chemo-/photothermal therapy based on supercritical technology-assisted chitosan–indocyanine green/luteolin nanocomposites for wound healing

Despite the success,it is highly challenging to battle against pathogenic biofilms-based chronic bacterial infections by conventional antibiotic therapy.Herein,we report a near-infrared(NIR)/acid-induced nanoplatform based on chitosan(CS)-coated indocyanine green(ICG,photosensitizer)/luteolin(LUT,a natural quorum sensing inhibitor)nanocomposites(ICG/LUT-CS)as antibacterial and antibiofilm agents for skin wound healing.Initially,the ICG/LUT nanoplatforms are prepared by the supercritical antisolvent technology and coated with the CS layer.The obtained ICG/LUT-CS with ultra-high encapsulation efficiency exhibited more favorable photothermal conversion effects and improved NIR laser/acid dual-induced drug release behavior than individual modalities,achieving exceptional bacteria-killing and biofilm elimination effects.Moreover,the ICG/LUT-CS realized the synergetic effects of chemotherapy and photothermal therapy outcomes for wound healing.Together,our findings provided an appealing strategy for the rapid preparation and future translational application of ICG/LUT-CS as an ideal agent for fighting against biofilm infections.

(Metal yolk)/(porous ceria shell)nanostructures for high-performance plasmonic photocatalysis under visible light

We describe a route to the preparation of(metal yolk)/(porous ceria shell)nanostructures through the heterogeneous growth of ceria on porous metal nanoparticles followed by the calcination-induced shrinkage of the nanoparticles.The approach allows for the control of the ceria shell thickness,the metal yolk composition and size,which is difficult to realize through common templating approaches.The yolk/shell nanostructures with monometallic Pt and bimetallic PtAg yolks featuring plasmon-induced broadband light absorption in the visible region are rationally designed and constructed.The superior photocatalytic activities of the obtained nanostructures are demonstrated by the selective oxidation of benzyl alcohol under visible light.The excellent activities are ascribed to the synergistic effects of the metal yolk and the ceria shell on the light absorption,electron-hole separation and efficient mass transfer.Our synthesis of the(metal yolk)/(porous ceria shell)nanostructures points out a way to the creation of sophisticated heteronanostructures for high-performance photocatalysis.