NIR-switchable local hydrogen generation by tandem bimetallic MOFs nanocomposites for enhanced chemodynamic therapy

The inadequate quantity of hydrogen peroxide(H_(2)O_(2))in cancer cells promptly results in the constrained success of chemodynamic therapy(CDT).Significant efforts made throughout the years;nevertheless,researchers are still facing the great challenge of designing a CDT agent and securing H_(2)O_(2) supply within the tumor cell.In this study,taking advantage of H_(2)O_(2) level maintenance mechanism in cancer cells,a nanozyme-based bimetallic metal-organic frameworks(MOFs)tandem reactor is fabricated to elevate intracellular H_(2)O_(2) levels,thereby enhancing CDT.In addition,under nearinfrared excitation,the upconversion nanoparticles(UCNPs)loaded into the MOFs can perform photocatalysis and generate hydrogen,which increases cellular susceptibility to radicals induced from H_(2)O_(2),inhibits cancer cell energy,causes DNA damages and induces tumor cell apoptosis,thus improving CDT therapeutic efficacy synergistically.The proposed nanozyme-based bimetallic MOFs-mediated CDT and UCNPs-mediated hydrogen therapy act as combined therapy with high efficacy and low toxicity.

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.

Biomedical applications of magnetosomes: State of the art and perspectives

Magnetosomes, synthesized by magnetotactic bacteria (MTB), have been used in nano- and biotechnological applications, owing to their unique properties such as superparamagnetism, uniform size distribution, excellent bioavailability, and easily modifiable functional groups. In this review, we first discuss the mechanisms of magnetosome formation and describe various modification methods. Subsequently, we focus on presenting the biomedical advancements of bacterial magnetosomes in biomedical imaging, drug delivery, anticancer therapy, biosensor. Finally, we discuss future applications and challenges. This review summarizes the application of magnetosomes in the biomedical field, highlighting the latest advancements and exploring the future development of magnetosomes.

Immune-regulating camouflaged nanoplatforms:A promising strategy to improve cancer nano-immunotherapy

Although nano-immunotherapy has advanced dramatically in recent times,there remain two significant hurdles related to immune systems in cancer treatment,such as(namely)inevitable immune elimination of nanoplat-forms and severely immunosuppressive microenvironment with low immunogenicity,hampering the perfor-mance of nanomedicines.To address these issues,several immune-regulating camouflaged nanocomposites have emerged as prevailing strategies due to their unique characteristics and specific functionalities.In this review,we emphasize the composition,performances,and mechanisms of various immune-regulating camouflaged nano-platforms,including polymer-coated,cell membrane-camouflaged,and exosome-based nanoplatforms to evade the immune clearance of nanoplatforms or upregulate the immune function against the tumor.Further,we discuss the applications of these immune-regulating camouflaged nanoplatforms in directly boosting cancer immunotherapy and some immunogenic cell death-inducing immunotherapeutic modalities,such as chemo-therapy,photothermal therapy,and reactive oxygen species-mediated immunotherapies,highlighting the cur-rent progress and recent advancements.Finally,we conclude the article with interesting perspectives,suggesting future tendencies of these innovative camouflaged constructs towards their translation pipeline.

Advances in hydrogel-based vascularized tissues for tissue repair and drug screening

The construction of biomimetic vasculatures within the artificial tissue models or organs is highly required for conveying nutrients,oxygen,and waste products,for improving the survival of engineered tissues in vitro.In recent times,the remarkable progress in utilizing hydrogels and understanding vascular biology have enabled the creation of three-dimensional(3D)tissues and organs composed of highly complex vascular systems.In this review,we give an emphasis on the utilization of hydrogels and their advantages in the vascularization of tissues.Initially,the significance of vascular elements and the regeneration mechanisms of vascularization,including angiogenesis and vasculogenesis,are briefly introduced.Further,we highlight the importance and advantages of hydrogels as artificial microenvironments in fabricating vascularized tissues or organs,in terms of tunable physical properties,high similarity in physiological environments,and alternative shaping mechanisms,among others.Furthermore,we discuss the utilization of such hydrogels-based vascularized tissues in various applications,including tissue regeneration,drug screening,and organ-on-chips.Finally,we put forward the key challenges,including multifunctionalities of hydrogels,selection of suitable cell phenotype,sophisticated engineering techniques,and clinical translation behind the development of the tissues with complex vasculatures towards their future development.

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.

Preparation of alumina-carbon composites with phloroglucinol-formaldehyde resin and their application in asymmetric hydrogenation

To overcome the shortcomings of single component carrier supported platinum(Pt)-based catalysts,herein,we demonstrate the fabrication of alumina combined mesoporous carbon to prepare a series of alumina-carbon composites and their corresponding Pt-based catalysts.The alumina-carbon composites Al@PhFC are synthesized by using phloroglucinol-formaldehyde resin as carbon source and aluminum acetylacetone as the aluminum source.Further,the effect of alumina content on the properties of the composites is investigated.The composites and catalysts are characterized by using XRD,XPS,N2 sorption,and TEM.The Pt/Al@PhFC-1.8 composite with appropriate amounts of alumina,pore diameter,and moderate Pt nanoparticle size,resulted in 99.5%of conversion efficiency and 77.4%of optical selectivity in the asymmetric hydrogenation of ethyl 2-oxo-4-phenylbutanoate(EOPB).Intere stingly,this composite can be used more than 20 times without a significant decrease in its performance.

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.

Preparation of aripiprazole-poly(methyl vinyl ether-co-maleic anhydride)nanocomposites via supercritical antisolvent process for improved antidepression therapy

Aripiprazole(ARI),a second-generation atypical antipsychotic drug approved for schizophrenia treatment,shows good efficacy against depression.However,the poorly aqueous solubility of ARI leads to low bioavailability and increased dose-related side effects,seriously limiting its application in pharmaceutics.Herein,we demonstrated the fabrication of ARI and poly(methyl vinyl etherco-maleic anhydride)(PVMMA)composite nanoparticles(PA NPs)using the supercritical antisolvent(SAS)process for enhancing its water-solubility and curative anti-depressant effects.Initially,the optimal experimental conditions(ARI/PVMMA mass ratio of 1:6,pressure of 10MPa,and solution flow rate of 0.75ml min^(-1))were determined by a 23 factorial experimental design,resulting in the PA NPs with an excellent particle morphology.In vitro cell experiments showed that PA NPs significantly inhibited the inflammatory response caused by the microglia activation induced by lipopolysaccharide(LPS).Similarly,mice behavioral tests demonstrated that PA NPs significantly improved LPS-induced depression-like behavior.Importantly,compared with free ARI,the LPS-induced activation of microglia in the mouse brain and the expression of inflammatory factors in serum were significantly reduced after treatment with PA NPs.Together,the innovative PA NPs designed by SAS processmight provide a candidate for developing new ARI-based nano-formulations.