Porous nanofibrous dressing enables mesenchymal stem cell spheroid formation and delivery to promote diabetic wound healing

Delayed and nonhealing of diabetic wounds imposes substantial economic burdens and physical pain on patients.Mesenchymal stem cells(MSCs)promote diabetic wound healing.Particularly when MSCs aggregate into multicellular spheroids,their therapeutic effect is enhanced.However,traditional culture platforms are inadequate for the efficient preparation and delivery of MSC spheroids,resulting in inefficiencies and inconveniences in MSC spheroid therapy.In this study,a three-dimensional porous nanofibrous dressing(NFD)is prepared using a combination of electrospinning and homogeneous freeze-drying.Using thermal crosslinking,the NFD not only achieves satisfactory elasticity but also maintains notable cytocompatibility.Through the design of its structure and chemical composition,the NFD allows MSCs to spontaneously form MSC spheroids with controllable sizes,serving as MSC spheroid delivery systems for diabetic wound sites.Most importantly,MSC spheroids cultured on the NFD exhibit improved secretion of vascular endothelial growth factor,basic fibroblast growth factor,and hepatocyte growth factor,thereby accelerating diabetic wound healing.The NFD provides a competitive strategy for MSC spheroid formation and delivery to promote diabetic wound healing.

Clinical safety and efficacy of allogenic human adipose mesenchymal stromal cells-derived exosomes in patients with mild to moderate Alzheimer’s disease:a phaseⅠ/Ⅱclinical trial

Background There have been no effective treatments for slowing or reversing Alzheimer’s disease(AD)until now.Growing preclinical evidence,including this study,suggests that mesenchymal stem cells-secreted exosomes(MSCs-Exos)have the potential to cure AD.Aims The first three-arm,drug-intervention,phase I/II clinical trial was conducted to explore the safety and efficacy of allogenic human adipose MSCs-Exos(ahaMSCs-Exos)in patients with mild to moderate AD.Methods The eligible subjects were assigned to one of three dosage groups,intranasally administrated with ahaMSCs-Exos two times per week for 12 weeks,and underwent follow-up visits at weeks 16,24,36 and 48.Results No adverse events were reported.In the medium-dose arm,Alzheimer’s Disease Assessment Scale–Cognitive section(ADAS-cog)scores decreased by 2.33(1.19)and the basic version of Montreal Cognitive Assessment scores increased by 2.38(0.58)at week 12 compared with baseline levels,indicating improved cognitive function.Moreover,the ADAS-cog scores in the medium-dose arm decreased continuously by 3.98 points until week 36.There were no significant differences in altered amyloid or tau deposition among the three arms,but hippocampal volume shrank less in the medium-dose arm to some extent.Conclusions Intranasal administration of ahaMSCs-Exos was safe and well tolerated,and a dose of at least 4×10^(8)particles could be selected for further clinical trials.

Bioinspired Double-stranded Yarn with Alternating Hydrophobic/Hydrophilic Patterns for High-efficiency Fog Collection

Efforts to develop innovative water harvesting strategies offer powerful solutions to alleviate the water crisis,especially in remote and arid areas.Inspired by the hydrophobic/hydrophilic pattern of desert beetles and water self-propulsion property of spider silks,a double-strand hydrophobic PVDF-HFP/hydrophilic PAN nanofibers yarn is proposed by electrospinning and twisting techniques.The double-strand cooperation approach allows for water deposition on hydrophobic PVDF-HFP segment and transport under the asymmetric capillary driving force of hydrophilic PAN segment,thus speeded up the aggregation and growth of droplets.The effects of the composition and the diameter ratio of the two primary yarns were studied and optimized for boosting fog collection performance.The double-strand anisotropic yarn not only provide an effective method for water harvesting,but also hold the potential to inspire innovative design concepts for fog collection materials in challenging environments.

Bioorthogonal microglia-inspired mesenchymal stem cell bioengineering system creates livable niches for enhancing ischemic stroke recovery via the hormesis

Mesenchymal stem cells(MSCs)experience substantial viability issues in the stroke infarct region,limiting their therapeutic efficacy and clinical translation.High levels of deadly reactive oxygen radicals(ROS)and proinflammatory cytokines(PC)in the infarct milieu kill transplanted MSCs,whereas low levels of beneficial ROS and PC stimulate and improve engrafted MSCs’viability.Based on the intrinsic hormesis effects in cellular biology,we built a microglia-inspired MSC bioengineering system to transform detrimental high-level ROS and PC into vitality enhancers for strengthening MSC therapy.This system is achieved by bioorthogonally arming metabolic glycoengineered MSCs with microglial membrane-coated nanoparticles and an antioxidative extracellular protective layer.In this system,extracellular ROSscavenging and PC-absorbing layers effectively buffer the deleterious effects and establish a microlivable niche at the level of a single MSC for transplantation.Meanwhile,the infarct’s inanimate milieu is transformed at the tissue level into a new living niche to facilitate healing.The engineered MSCs achieved viability five times higher than natural MSCs at seven days after transplantation and exhibited a superior therapeutic effect for stroke recovery up to 28 days.This vitality-augmented system demonstrates the potential to accelerate the clinical translation of MSC treatment and boost stroke recovery.

Okra‑Like Multichannel TiO@NC Fibers Membrane with Spatial and Chemical Restriction on Shuttle‑Effect for Lithium–Sulfur Batteries

It is especially important to coordinately design the structure and composition of the host in lithium–sulfur batteries(LSBs)for improving its physicochemical adsorption and conversion of lithium polysulfide,which can alleviate the harmful shuttle effect.Herein,a self-supporting multichannel nitrogen-doped carbon fibers membrane embedded with TiO nanoparticles(TiO@NC)was constructed as the electrode for LSBs.The inner channels and the embedded TiO nanoparticles offer spatial confinement and chemical binding for polysulfides,respectively.Moreover,the TiO nanoparticles have abundant oxygen vacancies that promote the conversion of polysulfides.In addition,the nitrogen-doped carbon skeleton can not only serve as highly conductive transportation paths for electrons,but also integrate with the inner channels to sustain the morphology and bear volume expansion during cycling processes.Therefore,the fabricated self-supporting quadruple-channel TiO@NC ultrathin fibers electrode exhibits a high initial specific capacity of 1342.8 mAh g^(-1)at 0.5 C and high-rate capability of 505.8 mAh g^(-1)at 4.0 C.In addition,it maintains 696.0 mAh g^(-1)over 500 cycles with only 0.059%capacity decay per cycle at the high current density of 2.0 C.The multichannel configuration combined with TiO nanoparticles provides a synergetic design strategy for fabricating high-performance electrodes in LSBs.

Tree Ring‑Inspired Fibrous Helix for UV Shielding and Warning Based on Photo‑electricity‑Acoustic Energy Conversion

Flexible wearable ultraviolet(UV)shielding,monitoring and warning devices have important applications in civil and mili-tary fields.However,most flexible wearable UV devices show unsatisfactory performance due to their poor stability and easy failure at large strains.Herein,inspired by tree rings,we engineered a hierarchical composite nanofibrous helix with an alternately stacked Archimedes spiral structure via a cost-effective strategy.Based on a photo-electricity-acoustic energy conversion system,we fabricated an all-in-one device exhibiting strain-insensitive UV protection at 0–500%strain for UV shielding as well as strain-sensitive UV monitoring at 500–1500%strain for UV early warning.Compared with previously reported common nanofibrous membrane devices,the as-prepared composite nanofibrous helix shows great advantages in terms of stability and UV protection,especially at large strains.Furthermore,the helix demonstrates multiple functions of wear resistance,antibacterial properties,biodegradation and knittability.This versatile strategy holds great promise for wearable electronics and multifunctional devices.

Three-dimensional architecture using hollow Cu/C nanofiber interpenetrated with MXenes for high-rate lithium-ion batteries

Improving the electron/ion transport ability and alleviating expansion during charging/discharging processes are vital for lithium-ion batteries(LIBs).In this work,a three-dimensional anode was fabricated using conductive hollow carbon-based nano tubes interpenetrated MXene architecture by directing the assembly of flexible electrospun hollow copper/carbon nanotubes and rigid Ti_(3)C_(2)T_(x) MXene nanosheets.The introduction of copper into carbon matrix leads to an improvement of lithium storage owing to the increase of disorder graphite.Additionally,the unique structure of the fabricated electrode provides a cross-network for fast electron diffusion by preventing the stack of nanotubes and MXene nanosheets.Consequently,the optimized electrode exhibits a high initial capacity of 424.45mAh·g^(-1) and maintains at 378.05 mAh·g^(-1) with a current density of 5 A·g^(-1) after 1000 cycles.This strategy of structural and chemical optimization provides new ideas for developing high-performance and durable electrochemical energy storage devices in the future.