Cerium-based nanoparticles for cancer photodynamic therapy

Metal-and metal-oxide-based nanoparticles have been widely exploited in cancer photodynamic therapy(PDT).Among these materials,cerium-based nanoparticles have drawn extensive attention due to their superior biosafety and distinctive physicochemical properties,especially the reversible transition between the valence states of Ce(Ⅲ)and Ce(Ⅳ).In this review,the recent advances in the use of cerium-based nanoparticles as novel photosensitizers for cancer PDT are discussed,and the activation mechanisms for electron transfer to generate singlet oxygen are presented.In addition,the types of cerium-based nanoparticles used for PDT of cancer are summarized.Finally,the challenges and prospects of clinical translations of cerium-based nanoparticles are briefly addressed.

Orthogonal Aza-BODIPY–BODIPY dyad as heavy-atom free photosensitizer for photo-initiated antibacterial therapy

Photodynamic antibacterial therapy shows great potential in bacterial infection and the reactive oxygen species(ROS)production of the photosensitizers is crucial for the therapeutic e®ect.Introducing heavy atoms is a common strategy to enhance photodynamic performance,while dark toxicity can be induced to impede further clinical application.Herein,a novel halogen-free photosensitizer Aza-BODIPY-BODIPY dyad NDB with an orthogonal molecular conguration was synthesized for photodynamic antibacterial therapy.The absorption and emission peaks of NDB photosensitizer in toluene were observed at 703 nm and 744 nm,respectively.The°uorescence(FL)lifetime was measured to be 2.8 ns in toluene.Under 730 nm laser illumination,the ROS generation capability of NDB was 3-fold higher than that of the commercial ICG.After nanoprecipitation,NDB NPs presented the advantages of high photothermal conversion e±ciency(39.1%),good photostability,and excellent biocompatibility.More importantly,in vitro antibacterial assay conrmed that the ROS and the heat generated by NDB NPs could extirpate methicillin-resistant S.aureus e®ectively upon exposure to 730 nm laser,suggesting the potential application of NDB NPs in photo-initiated antibacterial therapy.

Brightening heavily doped upconversion nanoparticles by tuning characteristics of core-shell structures

Heavily doped upconversion nanoparticles(UCNPs)potentially have exceptional photon upconversion abilities that are promising for diverse applications,such as lasing and super-resolution microscopy.However,heavily doped UCNPs typically can only offer mediocre upconversion luminescence intensity,and there still lacks general guidelines for the design and synthesis of heavily doped UCNPs.Herein,in order to boost the upconversion luminescence of heavily doped UCNPs,we studied the influence of characteristics of the core-shell structure on heavily doped UCNPs'upconversion luminescence.We find that some empirical guidelines derived from conventional UCNPs are not suitable for heavily doped UCNPs.Using NaYbF_(4):Tm@NaYF_(4) core-shell UCNPs with a high concentration of Yb_(3+)as a representative,our studies reveal that a rather thick inert NaYF4 shell is needed to protect the UCNPs from surface quenching,and the upconversion luminescence may undergo the cooperative sensitization process,which should be due to the highly concentrated Yb~(3+)dopant.In addition,the upconversion luminescence of heavily doped NaYbF4:Tm UCNPs exhibits no obvious dependence on the type of inert shell.Furthermore,our results show that confining both Yb~(3+)and Tm~(3+)dopants in a thin layer(known as theδ-doping strategy)does not work well in the heavily doped UCNPs.Accordingly,we propose a NaYbF_(4):Tm@NaYbF_(4)@NaYF_(4) core-shell-shell structure to enhance the luminescence of heavily doped UCNPs,by weakening the dissipation of excitation energy and strengthening the absorption.These findings should be helpful to establish general design principles for developing the brightest possible UCNPs that can meet the requirements of various applications.

Aza-BODIPY dye with unexpected bromination and high singlet oxygen quantum yield for photoacoustic imaging-guided synergetic photodynamic/photothermal therapy

Introducing heavy halogen atoms into organic small molecules is a practical strategy for efficient singlet oxygen(^(1)O_(2))generation.Generally,bromine or iodine atoms are introduced on the aza-borondipyrromethene(aza-BODIPY)core,rather than on the periphery aryl rings for efficient~1O_(2) generation.Herein,an aza-BODIPY dye NBDPBr with unexpected bromination on the periphery aryl rings was synthesized for photoacoustic(PA)imaging-guided synergistic photothermal therapy(PTT)and photodynamic therapy(PDT)in tumor cells.Owing to unexcepted bromination at the periphery aryl rings,NBDPBr demonstrated an outstanding singlet oxygen quantum yield(Φ_(Δ))of 66% which was superior to similar brominated photosensitizers previously reported.After encapsulation with amphiphilic polymer F-127,hydrophilic NBDPBr nanoparticles(NPs)were fabricated and exhibited an excellent photothermal conversion efficiency(η)of 43.0% under 660 nm photoirradiation.In vivo PA imaging results demonstrated that NBDPBr NPs could specifically accumulate at tumor sites and realized the maximum tumor retention at 7 h post-injection.All the in vitro and in vivo results indicated the significant potence of NBDPBr with unexpected bis-bromination for PA imaging-guided synergetic PDT/PTT.

Thermal-sensitive ionogel with NIR-light controlled adhesion for ultrasoft strain sensor

With the widespread prevailing of flexible electronics in human-machine interfaces,health monitor,and human motion detection,ultrasoft flexible sensors are urgently desired with critical demands in conformality.Herein,a temperature-sensitive ionogel with near-infrared(NIR)-light controlled adhesion is prepared by electrostatic interaction of poly(diallyl dimethylammonium chloride)(PDDA)and acrylic acid,as well as the incorporation of the conductive polydopamine modified polypyrrole nanoparticles(PPy-PDA NPs).The PPy-PDA NPs could weaken the tough interaction between polymer chains and depress the Young’s modulus of the ionogel,thus promoting the ionogel ultrasoft(34 kPa)and highly stretchable(1,013%)performance to tensile deformations.In addition,the high photothermal conversion capacity of PPy-PDA NPs ensured the ionogel excellent NIR-light controlled adhesion and temperature sensitivity,which facilitated the ionogel on-demand removal and promised a reliable thermal sensor.Moreover,the resulted ultrasoft flexible sensor exhibited high sensitivity and stability to both strain and pressure in a broad range of deformations,enabling a precise monitoring on various human motions and physiological activities.The temperature-sensitive,ultrasoft,and controlled adhesive capabilities prompted great potential of the flexible ionogel in medical diagnosis and wearable electronics.

Promoting near-infrared II fluorescence efficiency by blocking long-range energy migration

Generally,long wavelength absorbed near-infrared II(NIR-II)dyes have a low fluorescence efficiency in aggregate states for aggregate-caused quenching effect,simultaneously enhancing efficiency and extending absorption is a challenging issue for NIR-II dyes.Here,three benzo[1,2-c:4,5-c’]bis[1,2,5]thiadiazole(BBT)derivatives(TPA-BBT,FT-BBT,and BTBT-BBT)are used to clarify fluorescence quenching mechanisms.When the BBT derivatives are doped into a small molecule matrix,they show quite different fluorescence behaviors.Structuredistorted TPA-BBT displays fluorescence quenching originating from short-range exchange interaction,while FT-BBT and BTBT-BBT with a co-planar-conjugated backbone exhibit concentration-dependent quenching processes,namely changing from long-range dipole-dipole interaction to exchange interaction,which could be majorly ascribed to large spectral overlap between absorption and emission.By precisely tuning doping concentration,both FT-BBT and BTBT-BBT nanoparticles(NPs)present the optimal NIR-II fluorescence brightness at∼2.5 wt%doping concentration.The doped NPs have good biocompatibility and could be served as fluorescence contrast agents for vascular imaging with a high resolution under 980-nm laser excitation.Those paradigms evidence that molecular doping can promote fluorescence efficiency of long wavelength-absorbed NIR-II fluorophores via suppressing long-range energy migration.

Light-responsive organic artificial enzymes:Material designs and bio-applications

As significant biocatalysts,natural enzymes have exhibited a vast range of applications in biocatalytic reactions.However,the“always-on”natural enzyme activity is not beneficial for the regulation of catalytic processes,which limits their bio-applications.Recently,it has been extensively reported that various organic artificial enzymes exhibit prominent absorption and controlled activity under illumination,which not only creates a series of light-responsive catalytic platforms but also plays a key role in biosensing and biomedical research.To provide novel ideas for the design of artificial enzymes,we conduct this review to highlight the recent progress of light-responsive organic artificial enzymes(LOA-Enz).The specific photoresponse mechanism and various bio-applications of LOA-Enz are also presented in detail.Furthermore,the remaining challenges and future perspectives in this field are discussed.

Temperature-sensitive and solvent-resistance hydrogel sensor for ambulatory signal acquisition in“moist/hot environment”

To realize continuously and stably work in a“moist/hot environment”,flexible electronics with excellent humid resistance,antiswelling,and detection sensitivity are demanding.Herein,a solvent-resistant and temperature-ultrasensitive hydrogel sensor was prepared by combining MXene and quaternized chitosan(QCS)with the binary polymer chain.The strong electrostatic interaction between the QCS chain and the poly(acrylic acid)(PAA)network endows the hydrogel stability against solvent erosion,high temperature,and high humidity.The strong dynamic interaction between MXene and polymer matrix significantly improves the mechanical properties and sensing(strain and temperature)sensitivity of the hydrogel.The hydrogel strain sensor exhibits a high gauge factor(5.53),temperature/humidity tolerance(equilibrium swelling ratio of 2.5%at 80℃),and excellent cycle stability,which could achieve a remote and accurate perception of complex human motion and environment fluctuation under aquatic conditions.Moreover,the hydrogel sensor exhibits impressive thermal response sensitivity(-3.183%/℃),ultrashort response time(<2.53 s),and a low detection limit(<0.5℃)in a wide temperature range,which is applied as an indicator of the body surface and ambient temperature.In short,this study broadens the application scenarios of hydrogels in persistent extreme thermal and wet environments.

三维碳基材料在电解水中的应用（英文）

水分解制备氢气和氧气是能源转换的一种重要方法,除光解水之外,电解水也一直备受关注.电解水过程中,使用新型高效催化剂可以加快水分解并降低成本.最近,自支撑三维碳基材料由于其比表面积大、导电性强、耐酸碱性好等优点在电催化水分解领域引起研究者的广泛兴趣.本文总结了近年来三维碳基材料在析氢、析氧领域的研究现状,重点介绍了其在双电极体系中分解水同时制氢气和氧气的研究进展,指出了三维碳基材料在电解水领域存在的问题和未来的发展方向.

基于苊烯酰二亚胺小分子/二氧化钛双分子电子传输层的高效钙钛矿太阳能电池（英文）

设计合成高效n型小分子半导体作为钙钛矿太阳能电池的电子传输层对实现低温、可溶液加工的钙钛矿太阳能电池具有重要意义.本文合成了三个低LUMO能级、基于苊烯酰二亚胺的小分子受体材料AI1, AI2, AI3,系统表征了其光物理性质及电化学、热力学性质,研究了其在钙钛矿太阳能电池器件中的应用.当使用TiO_2/AI1作为电子传输层时,钙钛矿太阳能电池的平均光电转换效率为15%,比单独TiO_2电子传输层11.7%的平均光电转换效率有较大提升,表明基于苊烯酰二亚胺的小分子AI1, AI2, AI3是良好的电子传输层材料,可实现低温、可溶液加工的高效钙钛矿太阳能电池.

Graphene as an intermediary for enhancing the electron transfer rate： A free-standing Ni3S2@graphene@CogSs electrocatalytic electrode for oxygen evolution reaction

A highly active and stable oxygen evolution reaction （OER） electrocatalyst is critical for hydrogen production from water splitting. Herein, three-dimensional Ni3Sa@graphene@Co9S8 （Ni3S2@G@Co9S8）, a sandwich- structured OER electro-catalyst, was grown in situ on nickel foam; it afforded an enhanced catalytic performance when highly conductive graphene is introduced as an intermediary for enhancing the electron transfer rate and stability. Serving as a free-standing electrocatalytic electrode, Ni3S2@G@Co9S8 presents excellent electrocatalytic activities for OER： A low onset overpotential （2 mA·cm^-2 at 174 mV）, large anode current density （10 mA·cm^-2 at an overpotential of 210 mV）, low Tafel slope （66 mV·dec^-1）, and predominant durability of over 96 h （releasing a current density of N 14 mA·cm^-2 with a low and constant overpotential of 215 mV） in a 1 M KOH solution. This work provides a promising, cost-efficient electrocatalyst and sheds new light on improving the electrochemical performance of composites through enhancing the electron transfer rate and stability by introducing graphene as an intermediary.

Thermoresponsive Lignin-Reinforced Poly(Ionic Liquid)Hydrogel Wireless Strain Sensor

To meet critical requirements on flexible electronic devices,multifunctionalized flexible sensors with excellent electromechanical performance and temperature perception are required.Herein,lignin-reinforced thermoresponsive poly(ionic liquid)hydrogel is prepared through an ultrasound-assisted synthesized method.Benefitting from the electrostatic interaction between lignin and ionic liquid,the hydrogel displays high stretchability(over 1425%),excellent toughness(over 132 kPa),and impressive stress loading-unloading cyclic stability.The hydrogel strain sensor presents excellent electromechanical performance with a high gauge factor(1.37)and rapid response rate(198 ms),which lays the foundation for human body movement detection and smart input.Moreover,owing to the thermal-sensitive feature of poly(ionic liquid),the as-prepared hydrogel displays remarkable thermal response sensitivity(0.217℃^(-1))in body temperature range and low limit of detection,which can be applied as a body shell temperature indicator.Particularly,the hydrogel can detect dual stimuli of strain and temperature and identify each signal individually,showing the specific application in human-machine interaction and artificial intelligence.By integrating the hydrogel strain sensor into a wireless sensation system,remote motion capture and gesture identification is realized in real-time.

D-A-D structured selenadiazolesbenzothiadiazole-based near-infrared dye for enhanced photoacoustic imaging and photothermal cancer therapy

Near-infrared(NIR)small molecular organic dyes as photothermal agents for cancer photothermal therapy(PTT)have attracted considerable research attention.Herein,two donor-acceptor-donor(D-A-D)structured NIR dyes,BBTT and SeBTT,are rationally designed,where the only difference is one heteroatom within the acceptor unit varying from sulfur to selenium(Se).More importantly,SeBTT NPs exhibit stronger NIR absorbance and higher photothermal conversion efficiency(PTCE≈65.3%).In vivo experiments illustrate that SeBTT NPs can be utilized as a high contrast photoacoustic imaging(PAI)agent,and succeed in tumor suppression without noticeable damage to main organs under NIR photoirradiation.This study presents an effective molecular heteroatom surgery strategy to regulate the photothermal properties of NIR small molecules for enhanced PAI and PTT.

Recent progress of flexible and wearable strain sensors for human-motion monitoring

With the rapid development of human artificial intelligence and the inevitably expanding markets, the past two decades have witnessed an urgent demand for the flexible and wearable devices, especially the flexible strain sensors. Flexible strain sensors, incorporated the merits of stretchability, high sensitivity and skin-mountable,are emerging as an extremely charming domain in virtue of their promising applications in artificial intelligent realms, human-machine systems and health-care devices. In this review, we concentrate on the transduction mechanisms, building blocks of flexible physical sensors, subsequently property optimization in terms of device structures and sensing materials in the direction of practical applications. Perspectives on the existing challenges are also highlighted in the end.

Diketopyrrolopyrrole-derived organic small molecular dyes for tumor phototheranostics

Cancer is one of the leading causes of human death around the world. Phototherapy, including photodynamic therapy(PDT) and photothermal therapy(PTT), is an emerging light-triggered cancer treatment and shows the advantages of non-invasiveness and low side effects. The design and preparation of efficient phototherapeutic agents are of great significance for phototherapy. Diketopyrrolopyrrole(DPP) is a small molecular organic dye featuring outstanding photophysical properties, facile tuning of structures and properties, and excellent photostability;thus, phototherapeutic agents based on organic small molecular DPP derivatives have attracted significant research attention for not only phototherapy but also photodiagnosis of fluorescence imaging(FLI) and photoacoustic imaging(PAI). This review summarizes the recent progress of various DPP-based organic small molecules on phototheranostics during the last five years. The molecular structure design and their phototheranostics performances are discussed in detail,as will be of great help for further creation of DPP-based phototheranostics.

Boron difluoride formazanate dye for high-efficiency NIR-Ⅱ fluorescence imaging-guided cancer photothermal therapy

The small molecular second near-infrared(NIR-Ⅱ, 1000–1700 nm) dye-based nanotheranostics can concurrently combine deep-tissue photodiagnosis with in situ phototherapy, which occupies a vital position in the early detection and precise treatment of tumors. However, the development of small molecular NIR-Ⅱ dyes is still challenging due to the limited electron acceptors and cumbersome synthetic routes.Herein, we report a novel molecular electron acceptor, boron difluoride formazanate(BDF). Based on BDF, a new small molecular NIR-Ⅱ dye BDF1005 is designed and synthesized with strong NIR-I absorption at 768 nm and bright NIR-Ⅱ peak emission at 1034 nm. In vitro and in vivo experiments demonstrate that BDF1005-based nanotheranostics can be applied for NIR-Ⅱ fluorescence imaging-guided photothermal therapy of 4T1 tumor-bearing mice. Under 808 nm laser irradiation, tumor growth can be effectively inhibited. This work opens up a new road for the exploitation of NIR-Ⅱ small molecular dyes for cancer phototheranostics.

Small Molecular NIR-II Fluorophores for Cancer Phototheranostics

Phototheranostics integrates deep-tissue imaging with phototherapy(containing photothermal therapy and photodynamic therapy),holding great promise in early diagnosis and precision treatment of cancers.Recently,second near-infrared(NIR-II)fluorescence imaging exhibits the merits of high accuracy and specificity,as well as real-time detection.Among the NIR-II fluorophores,organic small molecular fluorophores have shown superior properties in the biocompatibility,variable structure,and tunable emission wavelength than the inorganic NIR-II materials.What’s more,some small molecular fluorophores also display excellent cytotoxicity when illuminated with the NIR laser.This review summarizes the progress of small molecular NIR-II fluorophores with different central cores for cancer phototheranostics in the past few years,focusing on the molecular structures and phototheranostic performances.Furthermore,challenges and prospects of future development toward clinical translation are discussed.

BSA stabilized photothermal-fenton reactor with cisplatin for chemo/chemodynamic cascade oncotherapy

Cisplatin(CDDP)-based chemotherapy is substantially limited in the clinic due to its high postoperative recurrence rate.Synergy therapy has been proven as a potent approach to minimize recurrence and achieve enhanced treatment effects.Herein,chemotherapy drug CDDP is assembled with the photothermal-Fenton agent of bovine serum albumin(BSA)stabilized gallic acid-functionalized iron nanoparticles(GA-Fe NPs)to achieve chemo/chemodynamic synergistic cascade oncotherapy.The Pt-GA-Fe NPs can be utilized to generate H_(2)O_(2) via the activation of nicotinamide adenine dinucleotide phosphate(NADPH)oxidases(NOXs)in the tumor microenvironment(TME),which would then greatly boost H2O2-depending chemodynamic therapy(CDT).The generated cytotoxic reactive oxygen species(hydroxyl radicals,·OH)and the depletion of glutathione(GSH)would further promote CDDP-induced DNA damage.Moreover,benefiting from the absorption in the near-infrared(NIR)region,Pt-GA-Fe NPs exhibit excellent photothermal conversion efficiency(η=45.5%)and allow photoacoustic imaging(PAI)guided photothermal therapy(PTT).In vitro and in vivo experiments show that synergy therapy can effectively kill cancer cells and successfully cure cancer without systemic toxicity.The work highlights a new type of therapeutic agent based on CDDP with the ability of H_(2)O_(2) self-generation,thermal responsiveness,and enhanced CDT effects for applications in cancer therapy.

S/Se-embedded acenaphthylene-imide-containing polycyclic heteroaromatic hydrocarbon

Acenapththylene-imide(An I),similar to naphthalene diimide(NDI),is an outstanding building block for organic functional materials and has gained a lot of research attention.Herein,Sulphur and Selenium-embedded AnI-containing polycyclic aromatic hydrocarbon molecules,AnI-SQ and AnI-SeQ,with[1,2,5]thiadiazolo[3,4-g]quinoxaline(SQ)and[1,2,5]selenadiazolo[3,4-g]quinoxaline(Se Q)are designed and synthesized with low-lying LUMO energy levels.The absorption and emission of AnI-SQ and An I-Se Q displayed a bathochromic shift upon protonation of the C=N bond.Besides,theoretical calculation indicates remarkable rigid planar backbones for both An I-SQ and An I-Se Q.Through self-assembly with polymeric Pluronic?F-127,corresponding hydrophilic nanoparticles(NPs)were prepared with low cytotoxicity.And AnI-SQ NPs could be applied for in vitro two-photon fluorescence imaging.

Thermoresponsive Lignin-Reinforced Poly(Ionic Liquid) Hydrogel Wireless Strain Sensor

To meet critical requirements on flexible electronic devices,multifunctionalized flexible sensors with excellent electromechanical performance and temperature perception are required.Herein,lignin-reinforced thermoresponsive poly(ionic liquid)hydrogel is prepared through an ultrasound-assisted synthesized method.Benefitting from the electrostatic interaction between lignin and ionic liquid,the hydrogel displays high stretchability(over 1425%),excellent toughness(over 132 kPa),and impressive stress loading-unloading cyclic stability.The hydrogel strain sensor presents excellent electromechanical performance with a high gauge factor(1.37)and rapid response rate(198 ms),which lays the foundation for human body movement detection and smart input.Moreover,owing to the thermal-sensitive feature of poly(ionic liquid),the as-prepared hydrogel displays remarkable thermal response sensitivity(0.217℃^(-1))in body temperature range and low limit of detection,which can be applied as a body shell temperature indicator.Particularly,the hydrogel can detect dual stimuli of strain and temperature and identify each signal individually,showing the specific application in human-machine interaction and artificial intelligence.By integrating the hydrogel strain sensor into a wireless sensation system,remote motion capture and gesture identification is realized in real-time.