Sustained release of vascular endothelial growth factor A and basic fibroblast growth factor from nanofiber membranes reduces oxygen/glucose deprivation-induced injury to neurovascular units

Upregulation of vascular endothelial growth factor A/basic fibroblast growth factor(VEGFA/b FGF)expression in the penumbra of cerebral ischemia can increase vascular volume,reduce lesion volume,and enhance neural cell proliferation and differentiation,thereby exerting neuroprotective effects.However,the beneficial effects of endogenous VEGFA/b FGF are limited as their expression is only transiently increased.In this study,we generated multilayered nanofiber membranes loaded with VEGFA/b FGF using layer-by-layer self-assembly and electrospinning techniques.We found that a membrane containing 10 layers had an ideal ultrastructure and could efficiently and stably release growth factors for more than 1 month.This 10-layered nanofiber membrane promoted brain microvascular endothelial cell tube formation and proliferation,inhibited neuronal apoptosis,upregulated the expression of tight junction proteins,and improved the viability of various cellular components of neurovascular units under conditions of oxygen/glucose deprivation.Furthermore,this nanofiber membrane decreased the expression of Janus kinase-2/signal transducer and activator of transcription-3(JAK2/STAT3),Bax/Bcl-2,and cleaved caspase-3.Therefore,this nanofiber membrane exhibits a neuroprotective effect on oxygen/glucose-deprived neurovascular units by inhibiting the JAK2/STAT3 pathway.

MXene@c-MWCNT Adhesive Silica Nanofiber Membranes Enhancing Electromagnetic Interference Shielding and Thermal Insulation Performance in Extreme Environments

A lightweight flexible thermally stable composite is fabricated by com-bining silica nanofiber membranes(SNM)with MXene@c-MWCNT hybrid film.The flexible SNM with outstanding thermal insulation are prepared from tetraethyl orthosilicate hydrolysis and condensation by electrospinning and high-temperature calcination;the MXene@c-MWCNT_(x:y)films are prepared by vacuum filtration tech-nology.In particular,the SNM and MXene@c-MWCNT_(6:4)as one unit layer(SMC_(1))are bonded together with 5 wt%polyvinyl alcohol(PVA)solution,which exhibits low thermal conductivity(0.066 W m^(-1)K^(-1))and good electromagnetic interference(EMI)shielding performance(average EMI SE_(T),37.8 dB).With the increase in func-tional unit layer,the overall thermal insulation performance of the whole composite film(SMC_(x))remains stable,and EMI shielding performance is greatly improved,especially for SMC_(3)with three unit layers,the average EMI SET is as high as 55.4 dB.In addition,the organic combination of rigid SNM and tough MXene@c-MWCNT_(6:4)makes SMC_(x)exhibit good mechanical tensile strength.Importantly,SMC_(x)exhibit stable EMI shielding and excellent thermal insulation even in extreme heat and cold environment.Therefore,this work provides a novel design idea and important reference value for EMI shielding and thermal insulation components used in extreme environmental protection equipment in the future.

Ultra-broadband microwave absorber and high-performance pressure sensor based on aramid nanofiber,polypyrrole and nickel porous aerogel

Electronic devices have become ubiquitous in our daily lives,leading to a surge in the use of microwave absorbers and wearable sensor devices across various sectors.A prime example of this trend is the aramid nanofibers/polypyrrole/nickel(APN)aerogels,which serve dual roles as both microwave absorbers and pressure sensors.In this work,we focused on the preparation of aramid nanofibers/polypyrrole(AP15)aerogels,where the mass ratio of aramid nanofibers to pyrrole was 1:5.We employed the oxidative polymerization method for the preparation process.Following this,nickel was thermally evaporated onto the surface of the AP15 aerogels,resulting in the creation of an ultralight(9.35 mg·cm^(-3)).This aerogel exhibited a porous structure.The introduction of nickel into the aerogel aimed to enhance magnetic loss and adjust impedance matching,thereby improving electromagnetic wave absorption performance.The minimum reflection loss value achieved was-48.7 dB,and the maximum effective absorption bandwidth spanned 8.42 GHz with a thickness of 2.9 mm.These impressive metrics can be attributed to the three-dimensional network porous structure of the aerogel and perfect impedance matching.Moreover,the use of aramid nanofibers and a three-dimensional hole structure endowed the APN aerogels with good insulation,flame-retardant properties,and compression resilience.Even under a compression strain of 50%,the aerogel maintained its resilience over 500 cycles.The incorporation of polypyrrole and nickel particles further enhanced the conductivity of the aerogel.Consequently,the final APN aerogel sensor demonstrated high sensitivity(10.78 kPa-1)and thermal stability.In conclusion,the APN aerogels hold significant promise as ultra-broadband microwave absorbers and pressure sensors.

Spatially Confined MXene/PVDF Nanofiber Piezoelectric Electronics

Piezoelectric nanofibers have received extensive attention in the field of electronic devices,but they are still restricted for further development,due to their limited dipole arrangement.Herein,we propose spatially confined MXene/polyvinylidene fluoride(PVDF)nanofibers for piezoelectric application,with dual functions of pressure sensing and energy harvesting.The spatial confinement of MXene/PVDF nanofibers can actively induce the optimally aligned-CH_(2)-/-CF_(2)-dipoles of PVDF and dramatically boost spontaneous polarization for piezoelectric enhancement.The voltage and current generated by fabricated MXene/PVDF(0.8 wt%)nanofiber piezoelectric electronic devices are respectively 3.97 times and 10.1 times higher than those generated by pure PVDF nanofibers.Based on these results,the developed bifunctional electronic devices are applied to monitor various human movements and to harvest energy.Notably,the results of this work allow for the development of nanofibers with excellent piezoelectric performance using a spatial confinement mechanism.

Bifunctional TiO_(2-x)nanofibers enhanced gel polymer electrolyte for high performance lithium metal batteries

Exploration of advanced gel polymer electrolytes(GPEs)represents a viable strategy for mitigating dendritic lithium(Li)growth,which is crucial in ensuring the safe operation of high energy density Li metal batteries(LMBs).Despite this,the application of GPEs is still hindered by inadequate ionic conductivity,low Li^(+)transference number,and subpar physicochemical properties.Herein,Ti O_(2-x)nanofibers(NF)with oxygen vacancy defects were synthesized by a one-step process as inorganic fillers to enhance the thermal/mechanical/ionic-transportation performances of composite GPEs.Various characterizations and theoretical calculations reveal that the oxygen vacancies on the surface of Ti O_(2-x)NF accelerate the dissociation of Li PF_6,promote the rapid transfer of free Li^(+),and influence the formation of Li F-enriched solid electrolyte interphase.Consequently,the composite GPEs demonstrate enhanced ionic conductivity(1.90m S cm^(-1)at room temperature),higher lithium-ion transference number(0.70),wider electrochemical stability window(5.50 V),superior mechanical strength,excellent thermal stability(210℃),and improved compatibility with lithium,resulting in superior cycling stability and rate performance in both Li||Li,Li||Li Fe PO_(4),and Li||Li Ni_(0.8)Co_(0.1)Mn_(0.1)O_(2)cells.Overall,the synergistic influence of nanofiber morphology and enriched oxygen vacancy structure of fillers on electrochemical properties of composite GPEs is comprehensively investigated,thus,it is anticipated to shed new light on designing high-performance GPEs LMBs.

A Novel NASICON‑Type Na_(3.5)MnCr_(0.5)Ti_(0.5)(PO_(4))_(3)Nanofiber with Multi‑electron Reaction for High‑Performance Sodium‑Ion Batteries

Sodium superionic conductors(NASICONs)show significant promise for application in the development of cathodes for sodium-ion batteries(SIBs).However,it remains a major challenge to develop the desired multi-electron reaction cathode with a high specific capacity and energy density.Herein,we report a novel NASICON-type Na_(3.5)MnCr_(0.5)Ti_(0.5)(PO_(4))_(3)cathode obtained by combining electrospinning and stepwise sintering processes.This cathode exhibits a high discharge capacity of 160.4 mAh g^(−1)and operates at a considerable medium voltage of 3.2 V.The Na_(3.5)MnCr_(0.5)Ti_(0.5)(PO_(4))_(3)cathode undergoes a multi-electron redox reaction involving the Cr^(3+/4+)(4.40/4.31 V vs.Na/Na^(+)),Mn^(3+/4+)(4.18/4.03 V),Mn^(2+/3+)(3.74/3.41 V),and Ti^(3+/4+)(2.04/2.14 V)redox couples.This redox reaction enables a three-electron transfer during the Na+intercalation/de-intercalation processes.As a result,the Na_(3.5)MnCr_(0.5)Ti_(0.5)(PO_(4))_(3)demonstrates a significant enhancement in energy density,surpassing other recently reported SIB cathodes.The highly reversible structure evolution and small volume changes during cycling were demonstrated with in-situ X-ray diffraction,ensuring outstanding cyclability with 77%capacity retention after 500 cycles.Furthermore,a NMCTP@C//Sb@C full battery was fabricated,which delivered a high energy density of 421 Wh kg−1 and exhibited good cyclability with 75.7%capacity retention after 100 cycles.The rational design of composition regulation with multi-metal ion substitution holds the potential to unlock new possibilities in achieving high-performance SIBs.

Amphoteric Supramolecular Nanofiber Separator for High-Performance Sodium-Ion Batteries

The separator is an essential component of sodium-ion batteries(SIBs)to determine their electrochemical performances.However,the separator with high mechanical strength,good electrolyte wettability and excellent electrochemical performance remains an open challenge.Herein,a new separator consisting of amphoteric nanofibers with abundant functional groups was fabricated through supramolecular assembly of natural polymers for SIB.The uniform nanoporous structure,remarkable mechanical properties and abundant functional groups(e.g.-COOH,-NH_(2)and-OH)endow the separator with lower dissolution activation energy and higher ion migration numbers.These metrics enable the separator to lower the barrier for desolvation of Na^(+),accelerate the migration of Na^(+),and generate more stable solid electrolyte interphase(SEI)and cathode electrolyte interphase(CEI).The battery assembled with the amphoteric nanofiber separator shows higher specific capacity and better stability than that assembled with glass fiber(GF)separator.

Controlled Twill Surface Structure Endowing Nanofiber Composite Membrane Excellent Electromagnetic Interference Shielding

Inspired by the Chinese Knotting weave structure,an electromagnetic interference(EMI)nanofiber composite membrane with a twill surface was prepared.Poly(vinyl alcohol-co-ethylene)(Pva-co-PE)nanofibers and twill nylon fabric were used as the matrix and filter templates,respectively.A Pva-co-PEMXene/silver nanowire(Pva-co-PE-MXene/AgNW,PM_(x)Ag)membrane was successfully prepared using a template method.When the MXene/AgNW content was only 7.4 wt%(PM_(7.4)Ag),the EMI shielding efficiency(SE)of the composite membrane with the oblique twill structure on the surface was 103.9 dB and the surface twill structure improved the EMI by 38.5%.This result was attributed to the pre-interference of the oblique twill structure in the direction of the incident EM wave,which enhanced the probability of the electromagnetic waves randomly colliding with the MXene nanosheets.Simultaneously,the internal reflection and ohmic and resonance losses were enhanced.The PM_(7.4)Ag membrane with the twill structure exhibited both an outstanding tensile strength of 22.8 MPa and EMI SE/t of 3925.2 dB cm^(-1).Moreover,the PM_(x)Ag nanocomposite membranes demonstrated an excellent thermal management performance,hydrophobicity,non-flammability,and performance stability,which was demonstrated by an EMI SE of 97.3%in a high-temperature environment of 140℃.The successful preparation of surface-twill composite membranes makes it difficult to achieve both a low filler content and a high EMI SE in electromagnetic shielding materials.This strategy provides a new approach for preparing thin membranes with excellent EMI properties.

Integrated adsorption and photocatalytic removal of methylene blue dye from aqueous solution by hierarchical Nb_(2)O_(5)@PAN/PVDF/ANO composite nanofibers

This work presents the development of hierarchical niobium pentoxide(Nb_(2)O_(5))-based composite nanofiber membranes for integrated adsorption and photocatalytic degradation of methylene blue(MB)pollutants from aqueous solutions.The Nb_(2)O_(5) nanorods were vertically grown using a hydrothermal process on a base electrospun nanofibrous membrane made of polyacrylonitrile/polyvinylidene fluoride/ammonium niobate(V)oxalate hydrate(Nb_(2)O_(5)@PAN/PVDF/ANO).They were characterized using field-emission scanning electron microscopy(FE-SEM),X-ray diffraction(XRD)analysis,and Fourier transform infrared(FTIR)spectroscopy.These composite nanofibers possessed a narrow optical bandgap energy of 3.31 eV and demonstrated an MB degradation efficiency of 96%after 480 min contact time.The pseudo-first-order kinetic study was also conducted,in which Nb_(2)O_(5)@PAN/PVDF/ANO nanofibers have kinetic constant values of 1.29×10^(-2) min^(-1) and 0.30×10^(-2) min^(-1) for adsorption and photocatalytic degradation of MB aqueous solutions,respectively.These values are 17.7 and 7.8 times greater than those of PAN/PVDF/ANO nanofibers without Nb_(2)O_(5) nanostructures.Besides their outstanding photocatalytic performance,the developed membrane materials exhibit advantageous characteristics in recycling,which subsequently widen their practical use in environmental remediation applications.

A new nano approach to prevent tumor growth in the local treatment of glioblastoma: Temozolomide and rutin-loaded hybrid layered composite nanofiber

Total resection of glioblastoma(GB)tumors is nearly impossible,and systemic administration of temozolomide(TMZ)is often inadequate.This study presents a hybrid layered composite nanofiber network(LHN)designed for localized treatment in GB tumor bed.The LHN,consisting of polyvinyl alcohol and core-shell polylactic acid layers,was loaded with TMZ and rutin.In vitro analysis revealed that LHN^(TMZ) and LHNrutin decelerated epithelial-mesenchymal transition and growth of stem-like cells,while the combination,LHN^(TMZ)+rutin,significantly reduced sphere size compared to untreated and LHNTMZ-treated cells(P<0.0001).In an orthotopic C6-induced GB rat model,LHNTMZ+rutin therapy demonstrated a more pronounced tumor-reducing effect than LHNTMZ alone.Tumor volume,assessed by magnetic resonance imaging,was significantly reduced in LHN^(TMZ)+rutin-treated rats compared to untreated controls.Structural changes in tumor mitochondria,reduced membrane potential,and decreased PARP expression indicated the activation of apoptotic pathways in tumor cells,which was further confirmed by a reduction in PHH3,indicating decreased mitotic activity of tumor cells.Additionally,the local application of LHNs in the GB model mitigated aggressive tumor features without causing local tissue inflammation or adverse systemic effects.This was evidenced by a decrease in the angiogenesismarker CD31,the absence of inflammation or necrosis in H&E staining of the cerebellum,increased production of IFN-γ,decreased levels of interleukin-4 in splenic T cells,and lower serum AST levels.Our findings collectively indicate that LHN^(TMZ)+rutin is a promising biocompatible model for the local treatment of GB.

Flexible Piezoelectric Sensor Based on Two‑Dimensional Topological Network of PVDF/DA Composite Nanofiber Membrane

Owing to the robust scalability,ease of control and substantial industrial applications,the utilization of electrospinning technology to produce piezoelectric nanofiber materials demonstrates a significant potential in the development of wearable products including flexible wearable sensors.However,it is unfortunate that the attainment of high-performance piezoelec-tric materials through this method remains a challenging task.Herein,a high-performance composite nanofiber membrane with a coherent and uniformly dispersed two-dimensional network topology composed of polyvinylidene fluoride(PVDF)/dopamine(DA)nanofiber membranes and ultrafine PVDF/DA nanofibers was successfully fabricated by the electrospinning technique.Based on the evidence obtained from simulations,experimental and theoretical results,it was confirmed that the unique structure of the nanofiber membrane significantly enhances the piezoelectric performance.The present PVDF/DA composite nanofibers demonstrated a remarkable piezoelectric performance such as a wide response range(1.5–40 N),high sensitivity to weak forces(0–4 N,7.29 V N^(-1)),and outstanding operational durability.Furthermore,the potential application of the present PVDF/DA membrane as a flexible wearable sensor for monitoring human motion and subtle physiological signals has also been validated.This work not only introduces a novel strategy for the application of electrospun nanofibers in sensors but also provides new insights into high-performance piezoelectric materials.

Self‑Assembling Peptide Nanofibers Anchored Parathyroid Hormone Derivative for Bone Tissue Engineering

Parathyroid hormone(PTH)has been used for bone regeneration through intermittent subcutaneous injection;however,the topical administration of PTH for bone repair remains challenging because of the overactivation of osteoclasts.Here,a PTH derivative,i.e.,PTHrP-1,which exhibits enhanced osteogenesis and relatively reduced osteoclastogenesis,is anchored to RADA16-I to fabricate a novel self-assembling peptide,called P1R16.Firstly,P1R16 self-assembles into long nanofibers with PTHrP-1 exposed to the side end,which interacts with Type I collagen(Col)to form P1R16-Col composites.The RADA16 segment in P1R16 helps the sustained release of P1R16 from the composites.Secondly,the P1R16 self-assembling peptide nanofibers exhibit multiple functions.The nanofibers promote stem cell proliferation and recruitment,and then direct stem cell fate towards osteogenic differentiation but not adpipogenic differentiation,improving the quality of the regenerated bone.The nanofibers further promote bone regeneration through bone remodeling between osteoblasts and osteoclasts.Thirdly,the P1R16 self-assembling peptide nanofibers also promote the proliferation and recruitment of endothelial cells,which facilitate the vascularization of implants to support bone regeneration further.Overall,the P1R16 self-assembling peptide nanofibers maintain multiple functions,including pro-proliferation,direction of stem cell fate,bone remodeling and vascularization,showing considerable promise for bone tissue engineering to repair bone defects or fractures.

Mass‑Producible Hybrid Polytetrafluoroethylene Nanofiber Mat with Radial Island‑Chain Architecture as Anti‑pathogen Cloth in Individual Protection

Developing an advanced individual protection cloth is a pivotal factor in combating global pathogen epidemics.However,formidable challenges are posed by the triangularity imbalance effect,necessitating the simultaneous fulfillment of require-ments for high comfort,high safety,and mass production.In this study,a mass-producible hybrid polytetrafluoroethylene nanofiber mat(HPNFM)was developed by integrating technologies of organic-inorganic hybridization and membrane asynchronous stretching.Exceptional comfort was attained by conferring waterproofing and breathability attributes,achieved through the radial island-chain architecture exhibiting hydrophobicity and nanoporosity.Furthermore,through the incorpo-ration of high-efficiency anti-pathogen nanoparticles,the HPNFM ensures high safety,demonstrating active antibacterial and antiviral effects.This is achieved through the synergistic effects of electrostatic induction and reactive oxygen species-based pathogen inactivation.More significantly,an HPNFM-based individual protective suit is designed and manufactured,which successfully encapsulates the advantages of high comfort,safety,and mass production,displaying competitiveness as a commercial product.Positioned as a viable strategy,this work holds substantial potential for practical applications in responding to future epidemics.

Shape‑Controllable Nanofiber Core‑Spun Yarn for Multifunctional Applications

Nanofiber core-spun yarn(NCSY)combines the advantages of traditional fibers and nanofibers to be widely used in smart wearable textiles,biomedical textiles,and functional textiles.Here,for the first time,the forming process of NCSY and its shape regulation mechanism were explored via finite element analysis and response surface analysis method to obtain mathematical model for predicting the various forms of yarn.As proof-of-concept applications,shape-controllable nanofiber core-spun yarns were prepared for thermal–moisture management and solar steam generation,respectively.The as-obtained shape-controllable PAN nanofiber/cotton composite yarns could achieve an interval control of average water transfer velocity in the horizontal(0.17–0.24 cm min^(-1))and vertical(0.24–0.33 cm min^(-1))directions within 30 min due to the arrangement of PAN nanofibers causes microchannels and hydrophilicity,matching the sweat secretion of human bodies under dynamic or static conditions and realizing the purpose of thermal and moisture comfort.Furthermore,PAN nanofiber wrapped CNTs/cotton composite yarn-based(PAN@CNTs-NCSY)evaporator was designed,which shows a fast water evaporation rate of 1.40 kg m^(-2)h^(-1),exceeding in most fabric-based evaporators reported to date.These findings have guiding significance for preparing rich style NCSY according to demand and designing functional and intelligent textiles via adjusting the type of core and shell fibers.

Engineering the spectra of photon triplets generated from micro/nanofiber

Quantum light sources are the core resources for photonics-based quantum information processing.We investigate the spectral engineering of photon triplets generated by third-order spontaneous parametric down-conversion in micro/nanofiber.The phase mismatching at one-third pump frequency gives rise to non-degenerate photon triplets,the joint spectral intensity of which has an elliptical locus with a fixed eccentricity of√6/3.Therefore,we propose a frequency-division scheme to separate non-degenerate photon triplets into three channels with high heralding efficiency for the first time.Choosing an appropriate pump wavelength can compensate for the fabrication errors of micro/nanofiber and also generate narrowband,non-degenerate photon triplet sources with a high signal-to-noise ratio.Furthermore,the long-period micro/nanofiber grating introduces a new controllable degree of freedom to tailor phase matching,resulting from the periodic oscillation of dispersion.In this scheme,the wavelength of photon triplets can be flexibly tuned using quasi-phase matching.We study the generation of photon triplets from this novel perspective of spectrum engineering,and we believe that this work will accelerate the practical implementation of photon triplets in quantum information processing.

Functional–Structural Integrated Aramid Nanofiber‑based Honeycomb Materials with Ultrahigh Strength and Multi‑Functionalities

Multifunctional microwave-absorbing(MA)honeycombs are in urgent demand both in civil and military fields,while they often suffer from great limitations due to the complicated preparation process,inferior strength,and the susceptible peeling off of the absorbent coatings.Herein,we develop a straightforward strategy of assembly of aramid nanofibers(ANFs)and MXene nanosheets to honeycombs,obtaining a functional–structural integrated microwave absorption aramid honeycomb(MAAH).Benefiting from the robust and integrated cell nodes and dense network structure,the compressive strength and toughness of ANF honeycomb can reach up to 18.6 MPa and 2.0 MJ m^(−3),respectively,which is 6 times and 25 times higher than that of commercial honeycomb.More importantly,the synergistic effect of the unique three-dimensional(3D)conductive network formed by uniformly distributed MXene and the hierarchical structure of the honeycomb endow it with superior wave-absorbing performance,which exhibits a minimum reflection loss(RL_(min))of−38.5 dB at a thickness of only 1.9 mm,and covering almost the entire X-band bandwidth.Additionally,MAAH presents exceptional infrared thermal stealth,sound absorption performance,and real-time monitoring of structural integrity.Therefore,these impressive multi-functionalities of MAAH with outstanding wave-absorbing performance,ultrahigh strength,along with the straightforward and easy-toscalable and recyclable manufacturing technique,demonstrating promising perspectives of the MAAH materials in aerospace and military fields.

An Asymmetric Natural Nanofiber with Rapid Temperature Responsive Detachability Inspired by Andrias davidianus for Full‑Thickness Skin Wound Healing

Wound dressing management is critical in healthcare,and frequent dressing changes for full-thickness skin wounds can hinder healing.Nanofiber dressings that resemble the extracellular matrix,have gained popularity in wound repair,however,it is challenging to explore how to frequently change it without affecting healing processing and avoiding secondary damage.Here,we developed a self-adhesive and detachable nanofiber dressing inspired by Andrias davidianus.Our asymmetric nanofiber dressing exhibits strong adhesion(26 kPa),to the wound at high temperature(approximately 25°C)to the wound surface and can be easily detached(4 kPa)at low temperature(below 8°C),enabling painless dressing changes that minimize secondary injuries.The dressing comprises an outer layer of polylactic acid which provides mechanical property,support,and pollution resistance,with an inner layer of nanofibrous membrane,composed of gelatin and Andrias davidianus skin secretions,which promotes cellular migration,enhances wound healing and possesses inherent antimicrobial properties.Furthermore,the all-natural nanofiber dressings can be prepared on a large scale and offer favorable biocompatibility to meet the basic requirements of wound dressings.These findings demonstrate the potential applicability of our multilayer nanofiber dressing for advancing wound healing practices.

Electrospun trilayer eccentric Janus nanofibers for a combined treatment of periodontitis

Oral diseases are common and prevalent,affecting people's health and seriously impairing their quality of life.The implantable class of materials for a safe,convenient,and comprehensive cure of periodontitis is highly desired.This study shows a proof-of-concept demonstration about the implant fibrous membranes.The fibers having a trilayer eccentric side-by-side structure are fabricated using the multiple-fluid electrospinning,and are fine candidates for treating periodontitis.In the trilayer eccentric side-by-side composite nanofibers,the outermost layer contains a hydrophilic polymer and a drug called ketoprofen,which can reach a release of 50%within 0.37 h,providing a rapid pain relief and anti-inflammatory effect.The middle layer is loaded with metronidazole,which is manipulated to be released in a sustained manner.The innermost layer is loaded with nano-hydroxyapatite,which can directly contact with periodontal tissues to achieve the effect of promoting alveolar bone growth.The experimental results indicate that the developed implant films have good wettability,fine mechanical properties,biodegradability,and excellent antibacterial properties.The implant films can reduce inflammatory responses and promote osteoblast formation by down-regulating interleukin 6 and up-regulating osteoprotegerin expression.In addition,their composite nanostructures exhibit the desired promotional effects on fibroblast attachment,infiltration,proliferation,and differentiation.Overall,the developed fibrous implant films show strong potential for use in a combined treatment of periodontitis.The protocols reported here pave a new way to develop multi-chamber based advanced fiber materials for realizing the desired functional performances through a robust process-structure-performance relationship.

Natural Human Skin‑Inspired Wearable and Breathable Nanofiber‑based Sensors with Excellent Thermal Management Functionality

Wearable sensors have been rapidly developed for application in various human monitoring systems.However,the wearing comfort and thermal properties of these devices have been largely ignored,and these characteristics urgently need to be stud-ied.Herein,we develop a wearable and breathable nanofiber-based sensor with excellent thermal management functionality based on passive heat preservation and active Joule heating effects.The multifunctional device consists of a micropatterned carbon nanotube(CNT)/thermoplastic polyurethane(TPU)nanofiber electrode,a microporous ionic aerogel electrolyte and a microstructured Ag/TPU nanofiber electrode.Due to the presence of a supercapacitive sensing mechanism and the appli-cation of microstructuration,the sensor shows excellent sensing performance,with a sensitivity of 24.62 kPa-1.Moreover,due to the overall porous structure and hydrophobicity of TPU,the sensor shows good breathability(62 mm/s)and water repellency,with a water contact angle of 151.2°.In addition,effective passive heat preservation is achieved by combining CNTs with high solar absorption rates(85%)as the top layer facing the outside,aerogel with a low thermal conductivity(0.063 W m-1 k-1)as the middle layer for thermal insulation,and Ag with a high infrared reflectance rate as the bottom layer facing the skin.During warming,this material yields a higher temperature than cotton.Furthermore,the active Joule heat-ing effect is realized by applying current through the bottom resistive electrode,which can quickly increase the temperature to supply controlled warming on demand.The proposed wearable and breathable sensor with tunable thermal properties is promising for monitoring and heat therapy applications in cold environments.

Electrical power generator from electrospun hybrid PVDF-BaTiO_(3)nanofiber membranes

To enhance the piezoelectric performance of piezoelectric polymer thin films in general,hybrid polyvinylidene difluoride(PVDF)and nanosized barium titanate(BaTiO_(3))piezoelectric films were prepared and their piezoelectric performance examined.The hybrid nanofibers were fabricated via electrospinning at an external voltage of 15 kV.The nonwoven fabrics were collected using a roller collection device,and their morphological structures were analyzed via scanning electron microscopy.The crystal structures of these piezoelectric films were characterized via micro-Raman spectroscopy.β-phase of the composite nanofiber membrane almost increased to twice owing to the addition of BaTiO_(3)nanoparticles.Compared with pure,electrospun PVDF piezoelectric film,the piezoelectric characteristics of the hybrid piezoelectric films were considerably enhanced because of the additional BaTiO_(3)nanoparticles.The maximum instantaneous open-circuit voltage of the hybrid PVDF-BaTiO_(3)nanofibers film can be high up to 80 V.The high-performance hybrid piezoelectric films exhibited notable prospects for applications in wearable electronic textiles.