GPCR/endocytosis/ERK signaling/S2R is involved in the regulation of the internalization,mitochondria-targeting and-activating properties of human salivary histatin 1

Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets and activates mitochondria,presenting an important molecular mechanism.However,its regulating signaling pathways remain to be elucidated.We investigated the influence of specific inhibitors of G protein-coupled receptors(GPCR),endocytosis pathways,extracellular signal-regulated kinases1/2(ERK1/2)signaling,p38 signaling,mitochondrial respiration and Na+/K+-ATPase activity on the uptake,mitochondria-targeting and-activating properties of F-Hst1.We performed a si RNA knockdown(KD)to assess the effect of Sigma-2 receptor(S2R)/Transmembrane Protein 97(TMEM97)—a recently identified target protein of Hst1.We also adopted live cell imaging to monitor the whole intracellular trafficking process of F-Hst1.Our results showed that the inhibition of cellular respiration hindered the internalization of F-Hst1.The inhibitors of GPCR,ERK1/2,phagocytosis,and clathrin-mediated endocytosis(CME)as well as siRNA KD of S2R/TMEM97 significantly reduced the uptake,which was accompanied by the nullification of the promoting effect of F-Hst1 on cell metabolic activity.Only the inhibitor of CME and KD of S2R/TMEM97 significantly compromised the mitochondria-targeting of Hst1.We further showed the intracellular trafficking and targeting process of F-Hst1,in which early endosome plays an important role.Overall,phagocytosis,CME,GPCR,ERK signaling,and S2R/TMEM97 are involved in the internalization of Hst1,while only CME and S2R/TMEM97 are critical for its subcellular targeting.The inhibition of either internalization or mitochondria-targeting of Hst1 could significantly compromise its mitochondria-activating property.

Brain endothelial cell-derived extracellular vesicles with a mitochondria-targeting photosensitizer effectively treat glioblastoma by hijacking the blood-brain barrier

Glioblastoma(GBM)is the most aggressive malignant brain tumor and has a high mortality rate.Photodynamic therapy(PDT)has emerged as a promising approach for the treatment of malignant brain tumors.However,the use of PDT for the treatment of GBM has been limited by its low blood-brain barrier(BBB)permeability and lack of cancer-targeting ability.Herein,brain endothelial cell-derived extracellular vesicles(bEVs)were used as a biocompatible nanoplatform to transport photosensitizers into brain tumors across the BBB.To enhance PDT efficacy,the photosensitizer chlorin e6(Ce6)was linked to mitochondria-targeting triphenylphosphonium(TPP)and entrapped into bEVs.TPPconjugated Ce6(TPP-Ce6)selectively accumulated in the mitochondria,which rendered brain tumor cells more susceptible to reactive oxygen species-induced apoptosis under light irradiation.Moreover,the encapsulation of TPP-Ce6 into b EVs markedly improved the aqueous stability and cellular internalization of TPP-Ce6,leading to significantly enhanced PDT efficacy in U87MG GBM cells.An in vivo biodistribution study using orthotopic GBM-xenografted mice showed that b EVs containing TPP-Ce6[b EV(TPP-Ce6)]substantially accumulated in brain tumors after BBB penetration via transferrin receptor-mediated transcytosis.As such,b EV(TPP-Ce6)-mediated PDT considerably inhibited the growth of GBM without causing adverse systemic toxicity,suggesting that mitochondria are an effective target for photodynamic GBM therapy.

Erlotinib combination with a mitochondria-targeted ubiquinone effectively suppresses pancreatic cancer cell survival

BACKGROUND Pancreatic cancer is a leading cause of cancer-related deaths.Increased activity of the epidermal growth factor receptor(EGFR)is often observed in pancreatic cancer,and the small molecule EGFR inhibitor erlotinib has been approved for pancreatic cancer therapy by the food and drug administration.Nevertheless,erlotinib alone is ineffective and should be combined with other drugs to improve therapeutic outcomes.We previously showed that certain receptor tyrosine kinase inhibitors can increase mitochondrial membrane potential(Δψm),facilitate tumor cell uptake ofΔψm-sensitive agents,disrupt mitochondrial homeostasis,and subsequently trigger tumor cell death.Erlotinib has not been tested for this effect.AIM To determine whether erlotinib can elevateΔψm and increase tumor cell uptake ofΔψm-sensitive agents,subsequently triggering tumor cell death.METHODSΔψm-sensitive fluorescent dye was used to determine how erlotinib affectsΔψm in pancreatic adenocarcinoma(PDAC)cell lines.The viability of conventional and patient-derived primary PDAC cell lines in 2D-and 3D cultures was measured after treating cells sequentially with erlotinib and mitochondria-targeted ubiquinone(MitoQ),aΔψm-sensitive MitoQ.The synergy between erlotinib and MitoQ was then analyzed using SynergyFinder 2.0.The preclinical efficacy of the twodrug combination was determined using immune-compromised nude mice bearing PDAC cell line xenografts.RESULTS Erlotinib elevatedΔψm in PDAC cells,facilitating tumor cell uptake and mitochondrial enrichment ofΔψm-sensitive agents.MitoQ triggered caspase-dependent apoptosis in PDAC cells in culture if used at high doses,while erlotinib pretreatment potentiated low doses of MitoQ.SynergyFinder suggested that these drugs synergistically induced tumor cell lethality.Consistent with in vitro data,erlotinib and MitoQ combination suppressed human PDAC cell line xenografts in mice more effectively than single treatments of each agent.CONCLUSION Our findings suggest that a combination of erlotinib and MitoQ has the potential to suppress pancreatic tumor cell viability effectively.

Mitochondria-targeting drug conjugates for cytotoxic, anti-oxidizing and sensing purposes:current strategies and future perspectives

mitochondrial-targeting moieties to anticancer drugs, antioxidants and sensor molecules. Among them, the most widely applied mitochondrial targeting moiety is triphenylphosphonium(TPP), which is a delocalized cationic lipid that readily accumulates and penetrates through the mitochondrial membrane due to the highly negative mitochondrial membrane potential. Other moieties, including short peptides,dequalinium, guanidine, rhodamine, and F16, are also known to be promising mitochondrial targeting agents. Direct conjugation of mitochondrial targeting moieties to anticancer drugs, antioxidants and sensors results in increased cytotoxicity, anti-oxidizing activity and sensing activity, respectively,compared with their non-targeting counterparts, especially in drug-resistant cells. Although many mitochondria-targeted anticancer drug conjugates have been investigated in vitro and in vivo, further clinical studies are still needed. On the other hand, several mitochondria-targeting antioxidants have been analyzed in clinical phases I, II and III trials, and one conjugate has been approved for treating eye disease in Russia. There are numerous ongoing studies of mitochondria-targeted sensors.

Mitochondria-targeting self-assembled nanoparticles derived from triphenylphosphonium-conjugated cyanostilbene enable site-specific imaging and anticancer drug delivery

Subcellular organelle-specific nanoparticles for simultaneous tumor targeting, imaging, and drug delivery are of enormous interest in cancer therapy. Herein, we report a selective mitochondria-targeting probe 1, which was synthesized by incorporating a triphenyl phosphine with a cyanostilbene and a long alkyl chain moiety. Probe 1 was found to display fluorescence via aggregation-induced emission （AIE）. The low molecular-weight cyanostilbene-based probe 1, with and without an anticancer drug, formed a narrow homogeneous nanorod with ca. 110 nm of length or nanopartides with ca. 20 nm diameter in aqueous media. The self-assembled cyanostilbene nanoparticles （N1） selectively accumulated in the mitochondria of cancer cells and emitted fluorescence. N1 was also able to deliver an anticancer drug, doxorubicin （DOX）, to the mitochondria with high efficiency. More importantl~ N1 exhibited highly selective cytotoxicity for cancer cells over normal cells. The great potential applications of this self-assembled nanoparticle to biological systems result from its ability to aggregate in the mitochondria. This aggregation led to a significant increase in the generation of intraceUular reactive oxygen species and to a decrease in the mitochondrial membrane potential in cancer cells. Furthermore, tumor tissue uptake experiments in mice proposed that the self-assembled N1 had the ability to internalize and deliver the anticancer drug into tumor tissues effectively. Moreover, both N1 and Nl-encapsulated doxorubicin （N1-DOX） effectively suppressed tumor growth in a xenograft model in vivo. Taken together, our findings indicate that applications of N1 as a mitochondrial targeting probe, drug delivery platform, and chemotherapeutic agent provide a unique strategy for potential image-guided therapy as well as a site-specific delivery system to cancer cells.

Mitochondria-targeting polydopamine-coated nanodrugs for effective photothermal-and chemo-synergistic therapies against lung cancer

Targetingmitochondria via nano platform emerged as an attractive anti-tumor pathway due to the central regulation role in cellar apoptosis and drug resistance.Here,a mitochondria-targeting nanoparticle(TOS-PDA-PEG-TPP)was designed to precisely deliver polydopamine(PDA)as the photothermal agent and alphatocopherol succinate(α-TOS)as the chemotherapeutic drug to the mitochondria of the tumor cells,which inhibits the tumor growth through chemo-and photothermal-synergistic therapies.TOSPDA-PEG-TPP was constructed by coating PDA on the surface of TOS NPs self-assembled byα-TOS,followed by grafting PEGand triphenylphosphonium(TPP)on their surface to prolong the blood circulation time and target delivery of TOS and PDA to the mitochondria of tumor cells.In vitro studies showed that TOS-PDA-PEGTPP could be efficiently internalized by tumor cells and accumulated atmitochondria,resulting in cellular apoptosis and synergistic inhibition of tumor cell proliferation.In vivo studies demonstrated that TOS-PDA-PEG-TPP could be efficiently localized at tumor sites and significantly restrain the tumor growth under NIR irradiation without apparent toxicity or deleterious effects.Conclusively,the combination strategy adopted for functional nanodrugs construction aimed at target-delivering therapeutic agents with different action mechanisms to the same intracellular organelles can be extended to other nanodrugs-dependent therapeutic systems.

Mitochondria-targeting NIR fluorescent probe for rapid,highly sensitive and selective visualization of nitroxyl in live cells,tissues and mice

Nitroxyl(HNO)has been reported to possess unique biological and pharmacological performances,and emerged as a novel therapy for congestive heart failure.Recent studies also suggest that HNO may be produced and involved in important metabolisms in mitochondria.However,due to its high reactivity and short life properties,fast,sensitive and selective observation and monitoring of HNO related dynamic changes in mitochondria still remains a great challenge.Herein,we synthesized a mitochondria-targeting near-infrared(NIR)fluorescent probe(DCMHNO)for rapid detection of HNO with remarkably high sensitivity,selectivity and photostability.DCMHNO shows fast response(about 4 min)towards HNO via 2-(diphenylphosphino)benzoyl group through the Staudinger reaction to boost the bright NIR emission(700 nm)with excellent sensitivity(detection limit of 13 nM),high p H stability and very low interference from other species.DCMHNO can selectively locate in mitochondria and visualize exogenous and endogenous HNO in live He La cells with high biocompatibility and photostability.The probe could also monitor the interaction between NO and H2 S that gives rise to the generation of HNO in live He La cells.In addition,DCMHNO was further utilized in ex vivo NIR imaging of HNO in live mouse liver tissues at the depth of about 50μm.In vivo imaging of HNO with high signal-to-noise ratio in live mice was also realized by using DCMHNO.These remarkable imaging performances could render NIR DCMNHNO as a useful tool to reveal HNO related dynamic changes in live samples.

Heterobifunctional PEG-grafted black phosphorus quantum dots: “Three-in-One”nano-platforms for mitochondria-targeted photothermal cancer therapy

Black phosphorus(BP)nano-materials,especially BP quantum dots(BPQDs),performs outstanding photothermal antitumor effects,excellent biocompatibility and biodegradability.However,there are several challenges to overcome before offering real benefits,such as poor stability,poor dispersibility as well as difficulty in tailoring other functions.Here,a“three-in-one”mitochondria-targeted BP nano-platform,called as BPQD-PEG-TPP,was designed.In this nano-platform,BPQDs were covalently grafted with a heterobifunctional PEG,in which one end was an aryl diazo group capable of reacting with BPQDs to form a covalent bond and the other end was a mitochondria-targeted triphenylphosphine(TPP)group.In addition to its excellent near-infrared photothermal properties,BPQD-PEG-TPP had much enhanced stability and dispersibility under physiological conditions,efficient mitochondria targeting and promoted ROS production through a photothermal effect.Both in vitro and in vivo experiments demonstrated that BPQD-PEG-TPP performed much superior photothermal cytotoxicity than BPQDs and BPQD-PEG as the mitochondria targeted PTT.Thus this“three-in-one”nanoplatform fabricated through polymer grafting,with excellent stability,dispersibility and negligible side effects,might be a promising strategy for mitochondria-targeted photothermal cancer therapy.

Nanopreparations for mitochondria targeting drug delivery system: Current strategies and future prospective

Mitochondria are a novel and promising therapeutic target for diagnosis, treatment and prevention of a lot of human diseases such as cancer, metabolic diseases and neurodegenerative disease. Owing to the mitochondrial special bilayer structure and highly negative potential nature, therapeutic molecules have multiple difficulties in reaching mitochondria. To overcome multiple barriers for targeting mitochondria, the researchers developed various pharmaceutical preparations such as liposomes, polymeric nanoparticles and inorganic nanoparticles modified by mitochondriotropic moieties like dequalinium (DQA),triphenylphosphonium (TPP), mitochondrial penetrating peptides (MPPs) and mitochondrial protein import machinery that allow specific targeting.The targeted formulations exhibited enhanced pharmacological effect and better therapeutic effect than their untargeted counterpart both in vitro and in vivo. Nanocarriers may be used for bio-therapeutic delivery into specific mitochondria that possess a great potential treatment of mitochondria related diseases.

Inflammation/bioenergetics-associated neurodegenerative pathologies and concomitant diseases:a role of mitochondria targeted catalase and xanthophylls

Various inflammatory stimuli are able to modify or even"re-program"the mitochondrial metabolism that results in generation of reactive oxygen species.In noncommunicable chronic diseases such as atherosclerosis and other cardiovascular pathologies,type 2 diabetes and metabolic syndrome,these modifications become systemic and are characterized by chronic inflammation and,in particular,"neuroinflammation"in the central nervous system.The processes associated with chronic inflammation are frequently grouped into"vicious circles"which are able to stimulate each other constantly amplifying the pathological events.These circles are evidently observed in Alzheimer's disease,atherosclerosis,type 2 diabetes,metabolic syndrome and,possibly,other associated pathologies.Furthermore,chronic inflammation in peripheral tissues is frequently concomitant to Alzheimer's disease.This is supposedly associated with some common genetic polymorphisms,for example,Apolipoprotein-Eε4 allele carriers with Alzheimer's disease can also develop atherosclerosis.Notably,in the transgenic mice expressing the recombinant mitochondria targeted catalase,that removes hydrogen peroxide from mitochondria,demonstrates the significant pathology amelioration and health improvements.In addition,the beneficial effects of some natural products from the xanthophyll family,astaxanthin and fucoxanthin,which are able to target the reactive oxygen species at cellular or mitochondrial membranes,have been demonstrated in both animal and human studies.We propose that the normalization of mitochondrial functions could play a key role in the treatment of neurodegenerative disorders and other noncommunicable diseases associated with chronic inflammation in ageing.Furthermore,some prospective drugs based on mitochondria targeted catalase or xanthophylls could be used as an effective treatment of these pathologies,especially at early stages of their development.

SOD mimicAEOL-10150 improve lifespan and delay brain aging via inhibition of senescence-associated secretory phenotype in SAMR1 strain

OBJECTIVE To observe the anti-aging effects of SOD mimic AEOL^(-1)0150 in antisenescence accelerated mouse resistant 1(SAMR1)strain.METHODS The lifespan of SAMR1 mice were observed by subcutaneous injection AEOL^(-1)0150 2 mg·kg-1once a week.Morris water maze,new object recognition,nesting and forced swimming were used to observe the behavioral changes of animals.Lymphocyte subgroups and ROS were measured by Flow cytometry.The cytokines levels were determined by Luminex method.The number of DCX+neurons in brain tissue was observed by immunofluorescence.RESULTS The results showed that AEOL^(-1)0150 could prolong the mean lifespan of SAMR1 mice,but it had no obvious effect on maximal lifespan.What′s more,AEOL^(-1)0150 could significantly improve the spatial learning memory of aged mice,but it could not increase the number of DCX+neurons in the hypothalamic MBH and hippocampal DG regions.Then,we observed the effects of AEOL^(-1)0150 on peripheral blood lymphocyte subgroups and cytokines.We found that AEOL^(-1)0150significantly modulated the lymphocyte subgroups and cytokine release.Especially,AEOL^(-1)0150 can dose-dependently inhibit plasma levels of SASP related inflammatory cytokines TNF-αand IL^(-1)7.CONCLUSION The results indicate that AEOL^(-1)0150 has anti-aging effects,and the effects are closely related to modulating immunity and inhibiting SASP production.

A mitochondria-targeted fluorescent probe for ratiometric detection of hypochlorite in living cells

Hypochlorous acid（HOCl） plays a vital role in many physiological and pathological processes as one of reactive oxygen species（ROS）. Developing highly sensitive and selective methods for HOCl detection is of significant interest. In this work, we developed a benzothiazole based probe 1 for ratiometric fluorescence detection of hypochlorite in living cells. The probe can detect HOCl with high selectivity, fast response（within 30 s） as well as low detection limit（0.18 mmol/L）. Fluorescence co-localization studies demonstrated that probe 1 was a mitochondria-targeted fluorescent probe. Furthermore, confocal fluorescence images of He La cell indicated that probe 1 could be used for monitoring intracellular HOCl in living cells. Finally, test strips experiment suggests that the probe 1 can detect the hypochlorous acid in tap water accompanied by remarkable color change.

An iridium(Ⅲ)-palladium(Ⅱ) metal-organic cage for efficient mitochondria-targeted photodynamic therapy

An Ir8 Pd4-heteronuclear metal-organic cage(MOC-51)was assembled from bipodal metalloligand[Ir(ppy)2(qpy)(BF4)](qpy=4,4′:2′,2″:4″,4′′′-quaterpyridine;ppy-2-phenylpridine)with Pd(Ⅱ)salt.The cubic barrel shaped MOC shows one-photon and two-photon excited deep-red emission,as well as large singlet oxygen quantum yields under visible light irradiation,therefore exhibiting great potentials in organelles-targeted cell imaging and photodynamic therapy(PDT).Compared with the Ir(Ⅲ)metalloligand,the Ir8 Pd4-MOC showed less dark toxicity and higher mitochondria-targeting efficiency.The localization in mitochondria overco mes the limitation of short lifetime and diffusion distance of ROS in cell,thus improved PDT effect can be obtained in low light dose usage of the MOC.This study presents the first case of Ir-based metal-organic cages for bio-applications in successful integration of imaging diagnosis and photodynamic therapy.

Liposome trade-off strategy in mitochondria-targeted NIR-cyanine: balancing blood circulation and cell retention for enhanced antitumor phototherapy in vivo

Cancer phototheranostics involving optical imaging-guided photodynamic therapy(PDT)and photothermal therapy(PTT)is a localized noninvasive approach in treating cancer.Mitochondria-targeted near-infrared(NIR)cyanines are excellent therapeutic photosensitizers of cancer.However,most mitochondria-targeted cyanines exist in the form of hydrophobic structures,which in vivo may cause cyanine aggregation during blood circulation,resulting in poor biocompatibility and limited therapeutic efficacy.Therefore,we developed a trade-off strategy by encapsulating mitochondria-targeted cyanines into liposomal bilayers(CyBI7-LPs),which balanced hydrophilicity that favored blood circulation and hydrophobicity that enhanced mitochondria tumor targeting.Moreover,CyBI7-LPs greatly minimized photobleaching of cyanine as self-generated reactive oxygen species(ROS)could rapidly escape from the liposomal bilayer,affording enhanced PTT/PDT efficacy.Bioorthogonal-mediated targeting strategy was further employed to improve uptake of tumor cells by modifying the liposomal surface to generate CyBI7-LPB.The CyBI7-LPB probe produced a tumor-to-background ratio(TBR)of approximately 6.4 at 24 HPI.Guiding by highly sensitive imaging resulted in excellent anti-tumor therapy outcomes using CyBI7-LPB due to the enhanced photothermal and photodynamic effects.This proposed liposomal nanoplatform exhibited a simple and robust approach as an imaging-guided synergistic anti-tumor therapeutic strategy.

Rational design of platinum(Ⅱ)complexes with orthogonally oriented triazolyl ligand with emission enhancement characteristics for cancer chemotherapy in vivo

The mitochondria are essential for tumorigenesis and have been regarded as important targets in cancer chemotherapy.Herein,the mitochondria-targeted platinum(Ⅱ)complexes have been prepared.The introduction of the triazole group with larger steric hindrance through post-click reaction converts the hybridization of carbon from sp to sp^(2),endowing the complexes with an orthogonally oriented ligand with restricted rotation and emission enhancement characteristics.Methylation of the triazolyl ligand has led to platinum(Ⅱ)complexes that can efficiently enter cancer cells and selectively accumulate in mitochondria,leading to significant enhancement in phosphorescence.In vivo anti-cancer investigations have demonstrated their distinct antitumor efficacy in substantial inhibition of tumor growth in breast cancer mice through dissipation of mitochondrial membrane potential,inducing apoptosis of tumor cell with negligibly systemic cytotoxicity.

RNA sequencing-based optimization of biological lipid droplets for sonodynamic therapy to reverse tumor hypoxia and elicit robust immune response

Mitochondria-targeted sonodynamic therapy(SDT)is a promising strategy to inhibit tumor growth and activate the anti-tumor immune responses.Identifying the mechanisms underlying mitochondria-targeted SDT,further optimizing its efficacy,developing novel sonosensitizer carriers with good biocompatibility pose major challenges to the clinical practice of SDT.In this study,we investigated the mechanisms of mitochondria-targeted SDT and demonstrated that it suppressed the mitochondrial electron transport chain(ETC)in pancreatic cancer cells through RNA-sequencing analysis.Based on these findings,we constructed the functional lipid droplets(LDs)(CPI-613/IR780@LDs),which combined mitochondria-targeted SDT with the tricarboxylic acid(TCA)cycle inhibitor CPI-613.CPI-613/IR780@LDs synergistically inhibited the TCA cycle and the ETC of mitochondrial aerobic respiration to reduce oxygen consumption and increase reactive oxygen species(ROS)generation at the tumor site,thus enhancing the efficacy of SDT in hypoxic pancreatic cancer.Moreover,the combination of mitochondria-targeted SDT and anti-PD-1 antibody exhibited excellent tumor inhibition and activated anti-tumor immune responses by increasing tumorinfiltrating CD8+T cells and reducing regulatory T cells,synergistically arresting the growth of both primary and metastatic pancreatic tumors.Meanwhile,lipid droplets are cell-derived biological carriers with natural mitochondrial targeting ability and can achieve efficient hydrophobic drug loading through active phagocytosis.Therefore,the functional lipid droplet-based SDT combined with anti-PD-1 antibody holds great potential in the clinical treatment of hypoxic pancreatic cancer.

Peptide-assembled siRNA nanomicelles confine MnOx-loaded silicages for synergistic chemical and gene-regulated cancer therapy

Chemodynamic therapy(CDT) is a promising therapeutic approach for in situ cancer treatment, but it is still hindered by inefficient single-modality treatment and the weak targeted delivery of reagents into mitochondria(the main site of intracellular ROS production). Herein, to obtain a multimodal strategy,peptide-assembled si RNA nanomicelles were prepared to confine ultrasmall MnOxin small silica cages(silicages), which is convenient for synergistic chemical and gene-regulated cancer therapy. Given the free energy and versatility of small silicages, as well as the excellent Fenton-like activity of ultrasmall MnOx,MnOx-inside-loaded silicages(10 nm) were prepared for CDT delivery to mitochondria. Subsequently, to obtain a synergistic CDT and gene silencing treatment, the peptide-mediated assembly of si RNA and MnOx-loaded silicages were employed to obtain silicage@MnOx-si RNA nanomicelles(SMS NMs). After multiple modifications, sequential cancer cell-targeted delivery, GSH-controlled reagent release of si RNA and mitochondria-targeted delivery of MnOx-loaded silicages were successfully achieved. Finally, by both in vitro and in vivo experiments, SMS NMs were confirmed to be effective for synergistic chemical and gene-regulated cancer therapy. Our findings expand the applications of silicages and initiate the development of multimodal CDT.

Defect-rich titanium nitride nanoparticle with high microwaveacoustic conversion efficiency for thermoacoustic imaging-guided deep tumor therapy

Pulse microwave excite thermoacoustic(TA)shockwave to destroy tumor cells in situ.This has promising applications for precise tumor therapy in deep tissue.Nanoparticle(NP)with high microwave-acoustic conversion is the key to enhance the efficiency of therapy.In this study,we firstly developed defect-rich titanium nitride nanoparticles(TiN NPs)for pulse microwave excited thermoacoustic(MTA)therapy.Due to a large number of local structural defects and charge carriers,TiN NPs exhibit excellent electromagnetic absorption through the dual mechanisms of dielectric loss and resistive loss.With pulsed microwave irradiation,it efficiently converts the microwave energy into shockwave via thermocavitation effect,achieving localized mechanical damage of mitochondria in the tumor cell and yielding a precise antitumor effect.In addition to the therapeutic function,the NP-mediated TA process also generates images that provide valuable information,including tumor size,shape,and location for treatment planning and monitoring.The experimental results showed that the TiN NPs could be efficiently accumulated in the tumor via intravenous infusion.With the deep tissue penetration characteristics of microwave,the proposed TiN-mediated MTA therapy effectively and precisely cures tumors in deep tissue without any detectable side effects.The results indicated that defect-rich TiN NPs are promising candidates for tumor therapy.

Synergetic lethal energy depletion initiated by cancer cell membrane camouflaged nano-inhibitor for cancer therapy

Mitochondrial bioenergy plays a vital role in the occurrence and development of cancer.Although strategies to impede mitochondrial energy supply have been rapidly developed,the anticancer efficacy is still far from satisfactory,mainly attributed to the hybrid metabolic pathways of mitochondrial oxidative phosphorylation(OXPHOS)and glycolysis.Herein,we construct a cancer cell membrane camouflaged nano-inhibitor,mTPPa-Sy nanoparticle(NP),which co-encapsulates OXPHOS inhibitor(mitochondrial-targeting photosensitizers:TPPa)and glycolysis inhibitor(syrosingopine(Sy))for synergistically blocking the two different energy pathways.The mTPPa-Sy NPs exhibit precision tumor-targeting due to the high affinity between the biomimic membrane and the homotypic cancer cells.Under laser irradiation,the mitochondrial-targeting TPPa,which is synthesized by conjugating pyropheophorbide a(PPa)with triphenylphosphin,produces excessive reactive oxygen species(ROS)and further disrupts the OXPHOS.Interestingly,OXPHOS inhibition reduces O_(2) consumption and improves ROS production,further constructing a closed-loop OXPHOS inhibition system.Moreover,TPPa-initiated OXPHOS inhibition in combination with the Sytriggered glycolysis inhibition results in lethal energy depletion,significantly suppressing tumor growth even after a single treatment.Our findings highlight the necessity and effectiveness of synergetic lethal energy depletion,providing a prospective strategy for efficient cancer therapy.