Nanosensitizers for sonodynamic therapy for glioblastoma multiforme: current progress and future perspectives

Glioblastoma multiforme(GBM) is the most common primary malignant brain tumor, and it is associated with poor prognosis. Its characteristics of being highly invasive and undergoing heterogeneous genetic mutation, as well as the presence of the blood–brain barrier(BBB), have reduced the efficacy of GBM treatment. The emergence of a novel therapeutic method, namely, sonodynamic therapy(SDT), provides a promising strategy for eradicating tumors via activated sonosensitizers coupled with low-intensity ultrasound. SDT can provide tumor killing effects for deep-seated tumors, such as brain tumors. However, conventional sonosensitizers cannot effectively reach the tumor region and kill additional tumor cells, especially brain tumor cells. Efforts should be made to develop a method to help therapeutic agents pass through the BBB and accumulate in brain tumors. With the development of novel multifunctional nanosensitizers and newly emerging combination strategies, the killing ability and selectivity of SDT have greatly improved and are accompanied with fewer side effects. In this review, we systematically summarize the findings of previous studies on SDT for GBM, with a focus on recent developments and promising directions for future research.

Research progress on reactive oxygen species production mechanisms in tumor sonodynamic therapy

In recent years,because of the growing desire to improve the noninvasiveness and safety of tumor treatments,sonodynamic therapy has gradually become a popular research topic.However,due to the complexity of the therapeutic process,the relevant mechanisms have not yet been fully elucidated.One of the widely accepted possibilities involves the effect of reactive oxygen species.In this review,the mechanism of reactive oxygen species production by sonodynamic therapy(SDT)and ways to enhance the sonodynamic production of reactive oxygen species are reviewed.Then,the clinical application and limitations of SDT are discussed.In conclusion,current research on sonodynamic therapy should focus on the development of sonosensitizers that efficiently produce active oxygen,exhibit biological safety,and promote the clinical transformation of sonodynamic therapy.

Recent advances of sonodynamic therapy in cancer treatment

Sonodynamic therapy(SDT) is an emerging approach that involves a combination of low-intensity ultrasound and specialized chemical agents known as sonosensitizers. Ultrasound can penetrate deeply into tissues and can be focused into a small region of a tumor to activate a sonosensitizer which offers the possibility of non-invasively eradicating solid tumors in a site-directed manner.In this article, we critically reviewed the currently accepted mechanisms of sonodynamic action and summarized the classification of sonosensitizers. At the same time, the breath of evidence from SDT-based studies suggests that SDT is promising for cancer treatment.

Induction of the apoptosis of cancer cell by sonodynamic therapy:a review

Ultrasound can be used not only in examination, but also in therapy, especially in the therapy of cancer. Sonodynamic therapy is an experimental cancer therapy method which uses ultrasound to enhance the cytotoxic effects of agents known as sonosensitizers. It has been tested in vitro and in vivo. The ultrasound could penetrate the tissue and cell under some of conditions which directly changes cell membrane permeability, thereby allowing the delivery of exogenous molecules into the cells in some degree. Ultrasound could inhibit the proliferation or induce the apoptosis of cancer cells in vitro or in vivo. Recent researches indicated low-frequency and low-intensity ultrasound could induce cell apoptosis, which could be strengthened by sonodynamic sensitivity, microbubbles, chemotherapeutic drugs and so on. Most kinds of ultrasound suppressed the proliferation of cancer cells through inducing the apoptosis of cancer cells. The mechanism of apoptosis is not clear. In this review, we will focus on and discuss the mechanisms of the induction of cancer cell apoptosis by ultrasound.

Beyond Antibiotics:Photo/Sonodynamic Approaches for Bacterial Theranostics

Rapid evolution and propagation of multidrug resistance among bacterial pathogens are outpacing the development of new antibiotics,but antimicrobial photodynamic therapy(aPDT)provides an excellent alternative.This treatment depends on the interaction between light and photoactivated sensitizer to generate reactive oxygen species(ROS),which are highly cytotoxic to induce apoptosis in virtually all microorganisms without resistance concern.When replacing light with low-frequency ultrasonic wave to activate sensitizer,a novel ultrasounddriven treatment emerges as antimicrobial sonodynamic therapy(aSDT).Recent advances in aPDT and aSDT reveal golden opportunities for the management of multidrug resistant bacterial infections,especially in the theranostic application where imaging diagnosis can be accomplished facilely with the inherent optical characteristics of sensitizers,and the generated ROS by aPDT/SDT cause broad-spectrum oxidative damage for sterilization.In this review,we systemically outline the mechanisms,targets,and current progress of aPDT/SDT for bacterial theranostic application.Furthermore,potential limitations and future perspectives are also highlighted.

Nanotechnology assisted photo-and sonodynamic therapy for overcoming drug resistance

Drug resistance is considered the most important reason for the clinical failure of cancer chemotherapy.Circumventing drug resistance and improving the efficacy of anticancer agents remains a major challenge.Over the past several decades,photodynamic therapy(PDT)and sonodynamic therapy(SDT)have attracted substantial attention for their efficacy in cancer treatment,and have been combined with chemotherapy to overcome drug resistance.However,simultaneously delivering sensitizers and chemotherapy drugs to same tumor cell remains challenging,thus greatly limiting this combinational therapy.The rapid development of nanotechnology provides a new approach to solve this problem.Nano-based drug delivery systems can not only improve the targeted delivery of agents but also co-deliver multiple drug components in single nanoparticles to achieve optimal synergistic effects.In this review,we briefly summarize the mechanisms of drug resistance,discuss the advantages and disadvantages of PDT and SDT in reversing drug resistance,and describe state-of-the-art research using nano-mediated PDT and SDT to solve these refractory problems.This review also highlights the clinical translational potential for this combinational therapy.

Killing effect of the combined treatment of ultrasound and hypocrellin B on Candidaalbicans

OBJECTIVE To investigate the killing effect of the combined treatment of ultrasound and hypocrellin B,an active component isolated from a natural product Hypocrella bambuase,on Candida albicans.METHODS At first,Candida albicans are incubated with hypcrellin B and the uptake of hypocrellin B in Candida albicans was determined using fluorescence intensity analysis.And then the sensitized Candida albicans were exposed to low-intensity of ultrasound.After the combined treatment of ultrasound and hypocellin B,the growth of Candida albicans was evaluated using the colony counting method,and membrane integrity of Candida albicans was also analyzed by a flow cytometry with propidium iodide staining.RESULTS Hypocrellin B was fast absorbed by candida albicans.The growth of candida albicans was more significantly inhibited by the combined treatment of ultrasound and hypocrellin B than the controls(P<0.05).The more marked damages to membrane integrity were found in the combined treatment than the controls(P<0.05).CONCLUSION The combined treatment of ultrasound and hypocrellin B had significant killing effect on Candida albicans,indicating sonodynamic therapy with hypocrellin B from natural product might be a potential approach for combating fungal infections.

Effect of sonodynamic action of hypocrellin B on biofilm-producing Enterococcus faecalis

OBJECTIVE To investigate the effect of sonodynamic action on biofilm-producing Enterococcus faecalis using hypocrellin B from a natural product Hypocrella bambuase as a sensitizer.METHODS The uptake of hypocrellin B in biofilm-producing Enterococcus faecalis was measured using the fluorescent analysis method.After the combined treatment of hypocrellin B and ultrasound,the growth of biofilm-producing Enterococcus faecalis was measured using the colony counting method,the membrane integrity was detected using a flow cytometric analysis with propidium iodide staining.Chromosomal DNA of bacteria was analysed using apulsed-field gel electrophoresis(PFGE).RESULTS The uptake of hypocrellin B in biofilm-producing Enterocuccus faecalis reached a high peak at the 20 min incubation.After the combined treatment of hypocrellin B,the growth of biofilm-producing Enterocuccus faecalis significantly descreased and membrane integrity was remarkably damaged.However,no remarkable change in bacterial DNA was found.CONCLUSION Sonodynamic action of hypocrellin B had significant killing activity on Enterocuccus faecalis.

Low Frequency Ultrasonication Induced Antitumor Effect in 5-Aminolevulinic Acid Treated Malignant Glioma

We investigated the feasibility of sonodynamic therapy for glioma by low frequency ultrasoundwith5-aminolevulinic acid (5-ALA), a precursor of protoporphyrin IX (PpIX) in heme synthetic process. In vivo tumor model was made by inoculating human glioma cell line U87-MG subcutaneously in nude mice. The tumor was sonicated by 25-kHz ultrasound 4 hours following administration of 5-ALA. The tumor size decreased in 5-ALA administered (ALA(+)US(+)) mice, while increased in non-5-ALA administrated (ALA(-)US(+)) mice and non-sonicated mice (ALA(+)US(-)). The immunohistochemical analysis revealed an apoptotic change in tumor tissue of ALA(+)US(+) mice. The results showed the therapeutic effect of 25 kHz ultrasound for the glioma in 5-ALA administered tumor-bearing mice by inducing apoptotic change of tumor cells. This is a first report to elucidate the feasibility of therapeutic use of 25 kHz, relatively low frequency, ultrasound in sonodynamic therapy using 5-ALA as a sonosensitizer precursor. The utilization of this frequency will contribute to the development of sonodynamic therapy for gliomas and the spread of this technique in many hospitals that possess ultrasonic aspirators.

Sonodynamic Antitumor Effect of Benzoporphyrin Derivative Monoacid Ring A on KLN205 Cells

Sonodynamic therapy is a new cancer treatment based on the synergetic effect of ultrasound and a drug. In this study, ultrasonically induced antitumor effects of benzoporphyrin derivative monoacid ring A (BPD-MA) on KLN205 cells were investigated. KLN205 cells were irradiated at an ultrasonic frequency of 3 MHz with 10 μg/ml BPD-MA. The ultrasonically induced cell damage significantly increased as an ultrasonic intensity and ultrasound exposure time increased. Confocal microscopic examination revealed that the irradiated cells were induced chromatin condensation and phosphatidylserine exposure. The synergistic effect of the ultrasound exposure and BPD-MA on the tumor cell adhesion rate was significant.

Design consideration of phthalocyanines as sensitizers for enhanced sono-photodynamic combinatorial therapy of cancer

Cancer remains one of the diseases with the highest incidence and mortality globally.Conventional treatment modalities have demonstrated threatening drawbacks including invasiveness,noncontrollability,and development of resistance for some,including chemotherapy,radiation,and surgery.Sono-photodynamic combinatorial therapy(SPDT)has been developed as an alternative treatment modality which offers a non-invasive and controllable therapeutic approach.SPDT combines the mechanism of action of sonodynamic therapy(SDT),which uses ultrasound,and photodynamic therapy(PDT),which uses light,to activate a sensitizer and initiate cancer eradication.The use of phthalocyanines(Pcs)as sensitizers for SPDT is gaining interest owing to their ability to induce intracellular oxidative stress and initiate toxicity under SDT and PDT.This review discusses some of the structural prerequisites of Pcs which may influence their overall SPDT activities in cancer therapy.

MOF负载Weel抑制剂实现p53突变胆囊癌的合成致死靶向治疗

Adavosertib(ADA)is a WEE1 inhibitor that exhibits a synthetic lethal effect on p53-mutated gallbladder cancer(GBC).However,drug resistance due to DNA damage response compensation pathways and high toxicity limits further applications.Herein,estrone-targeted ADA-encapsulated metal–organic frameworks(ADA@MOF-EPL)for GBC synthetic lethal treatment by inducing conditional factors are developed.The high expression of estrogen receptors in GBC enables ADA@MOF-EPL to quickly enter and accumulate near the cell nucleus through estrone-mediated endocytosis and release ADA to inhibit WEE1 upon entering the acidic tumor microenvironment.Ultrasound irradiation induces ADA@MOF-EPL to generate reactive oxygen species(ROS),which leads to a further increase in DNA damage,resulting in a higher sensitivity of p53-mutated cancer cells to WEE1 inhibitor and promoting cell death via conditional synthetic lethality.The conditional factor induced by ADA@MOF-EPL further enhances the antitumor efficacy while significantly reducing systemic toxicity.Moreover,ADA@MOF-EPL demonstrates similar antitumor abilities in other p53-mutated solid tumors,revealing its potential as a broad-spectrum antitumor drug.

Ultrasound-driven self-decomposition porphyrins as metal-free CO precursors for gas and sonodynamic synergistic therapy

Carbon monoxide(CO) is an endogenous therapeutic gas with an anti-tumor effect. The precise delivery and controlled release of CO in tumor tissues play crucial roles in anti-cancer treatment. However, efficient in situ generation of CO from metal-free COreleasing molecules(CORMs) remains a formidable challenge. Herein, we develop ultrasound(US)-driven self-decomposition porphyrin as organic and metal-free US-CORMs, which can spatiotemporally control the CO release(347 mmol CO/mol porphyrin) efficiently under physiologically harmless US conditions(1.0 MHz, 1.5 W/cm^(2), 50% duty cycle, 50 min). Moreover,porphyrin as a sonosensitizer can also generate reactive oxygen species(ROS) under US treatment to achieve sonodynamic therapy(SDT). Advanced functions of such porphyrin-based CORMs in CO gas-sonodynamic synergistic treatment have been demonstrated by evaluating the in vitro and in vivo anti-tumor effects.

Metal-based inorganic nanocrystals for biological sonodynamic therapy applications:recent progress and perspectives

With the fast development of technology for the treatment of tumor and bacteria,photo-therapeutic strate-gies emerge as a kind of highly effective and common treatment,but the low tissue penetration depth of light limits their development.Sonodynamic therapy(SDT),as an efficient and non-invasive treatment,attracts more people's attention due to the inherent property of high tissue penetration.The soft tissue penetration depth of ultrasound(US)can even reach more than 10 cm,which has great advantage over that of light.Therefore,many sonosensitizers are studied and applied to SDT-based therapy.Metal-based inorganic nanocrystals are able to generate more reactive oxygen species(ROS)due to the special composition and band structure.The representative achievements and the specific functions of the nanocrystals sonosensitizers are summarized in this work,and the relationship of structure/composition-SDT performance and the internally regulated composite is revealed.Syner-gistic effects of SDT in combination with other therapeutic modalities are mainly highlighted.At the same time,the critical and potential issues and future perspectives are addressed.

Porphyrin-based metal-organic framework nanocrystals for combination of immune and sonodynamic therapy

Immune therapy based on programmed death-ligand 1(PD-L1)is widely used to treat human tumors.The current strategies to improve immune checkpoint blockade therapy fail in rescuing increased expression of PD-L1 in tumor issues.Here,we for the first time synthesized the metal-organic framework(MOF)nanocrystals of rare-earth element dysprosium(Dy)coordinated with tetrakis(4-carboxyphenyl)porphyrin(TCPP),which show well-defined two-dimensional morphologies.The MOF nanocrystals of Dy-TCPP could apparently reduce PD-L1 expression in tumor cells both in vitro and in vivo,and therefore display effective tumor treatment through immune therapy without any immune checkpoint inhibitor drugs.Considering the sensitivity of TCPP ligand toward ultrasound,the prepared Dy-TCPP can also realize sonodynamic therapy(SDT)besides immune therapy.In addition,the Dy-TCPP nanocrystals can efficiently obtain T_(2)-weight magnetic resonance imaging(MRI)of tumor sites.Our study provides the Dy-TCPP nanocrystals as promising diagnostic MRI-guided platforms for the combined treatment on tumors with SDT and immune therapy.Moreover,this strategy succeeds in reducing the elevated expression of PD-L1 in tumor cells,which might serve as a novel avenue for tumor immunotherapy in future.

Evoking robust immunogenic cell death by synergistic sonodynamic therapy and glucose depletion using Au clusters/single atoms modified TiO_(2)nanosheets

Facilitated by reactive oxygen species(ROS)-involved therapies,tumor cells undergo immunogenic cell death(ICD)to stimulate long-term immunity response.However,it is hard to trigger abundant and large-scale ICD for satisfactory cancer immunotherapy.Herein,a multifunctional sonosensitizer that consists of Au single atoms and clusters anchored on TiO_(2)nanosheets(named Au_(S/C)-TiO_(2))is reported for augmented sonodynamic therapy(SDT)and glucose depletion,which ultimately induce robust ICD due to the improved ROS generation and strong endoplasmic reticulum(ER)stress.The synergy effect between Au cluster/single atom with TiO_(2)nanosheets intensifies apoptosis and ICD pathways to inhibit 80%of tumor cells through in vivo analyses.Furthermore,immune cells in vivo analyses verify the effectiveness of Au_(S/C)-TiO_(2)sonosensitizer towards the induction of antitumor immunity.This study thus reveals that simultaneous presence of ROS generation and strong ER stress can efficiently evoke a strong ICD-mediated immune response.

基于二维Nb_(2)C的纳米平台增强声动力抗菌治疗并促进骨修复

快速消除感染和促进骨再生是骨髓炎临床治疗的两个关键环节.当前迫切需要开发高效的生物活性声敏剂用于声动力治疗(SDT).在此,我们设计了一种二维Nb_(2)C纳米片修饰的卟啉基金属有机框架纳米平台(HNTM/Nb_(2)C)用于在超声辐照下同时消除感染和加速骨再生.通过在HNTM和Nb_(2)C纳米片之间构建肖特基结,实现了超声辐照下快速的电荷转移并抑制电子-空穴对的重组,从而产生丰富的活性氧.这种新型的声敏剂可以加速干细胞向成骨细胞的分化.RNA测序表明,该HNTM/Nb_(2)C纳米平台通过阳离子释放及超声响应电流引起的ATP合成耦合的电子传递诱导干细胞分化.此外,KEGG通路富集分析表明,Nb离子可能通过激活Wnt信号通路进一步促进成骨.我们的研究为骨髓炎的高效SDT提供了新的策略,该策略通过声响应电流联合离子疗法,实现了感染的消除同时促进了骨再生.

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.

Ultrasound cascade regulation of nano-oxygen hybrids triggering ferroptosis augmented sonodynamic anticancer therapy

Sonodynamic therapy(SDT)has attracted great interest in the field of cancer therapy because of its non-invasiveness,deep penetration,spatiotemporal controllability.However,the sonodynamic effect is severely hindered by hypoxia and a high glutathione(GSH)level in tumor microenvironment.In this work,a new type of nanohybrid sonosensitizer is designed,which incorporates several prominent advantages of organic,inorganic,natural sonosensitizers for imaging-guided SDT and ferroptosis induction.As an endogenous transporter,hemoglobin(Hb)has dual functions of oxygen and iron supplement.Apparently,Hb can transport iron to the tumor site for Fe-dependent ferroptosis,yet this oxygen carrier is able to enhance the sensitivity of tumor cells to oxygen-driven SDT.We innovatively hybridized Hb,sinoporphyrin sodium(DVDMS),titanium dioxide(TiO_(2))to prepare an integrated nano-oxygen carrier(designated as HDT)for multifarious cancer theranostics,which not only attained satisfactory sonosensitization of DVDMS/TiO_(2)but also achieved oxygen-boosted SDT and potent ferroptosis via Hb.Under ultrasound irradiation,the oxygenation of HDT markedly amplified the generation of reactive oxygen species(ROS)in hypoxic tumors,promoted the valence transition of Hb to accelerate Fenton reaction,led to ferroptosis.This strategy virtually eradicated tumors in situ and exhibited immunoregulatory potential for augmenting anti-tumor effects in vivo and in vitro through ROS formation,O_(2)self-supplement,GSH depletion,lipid peroxidation.Collectively,HDT demonstrated excellent dual-modal imaging performance,providing a valuable platform for photoacoustic/fluorescence-guided SDT and ferroptosis induction in tumor cells.

Ultrasound-active ReCORM-AIEgen for gas and sonodynamic therapy of mycobacterium biofilms

Bacterial infection is the leading cause of many severe inflammation diseases. The development of novel and effective therapeutic approaches to counter bacterial infections, especially for drug-resistant bacteria, is essential. Herein, we have successfully developed an ultrasound-active tricarbonyl rhenium(Ⅰ) complex with tetraphenylethylene(TPE) modification(RePyTPE) for CO gas therapy and sonodynamic therapy of bacterial infections. RePy-TPE produced reactive oxygen species and released CO under ultrasound irradiation. In addition, RePy-TPE showed aggregation-induced emission in water due to the introduction of TPE, which enhanced the yield of ^(1)O_(2) generation in a biological aqueous solution. The produced ^(1)O_(2) and released CO killed mycobacterium smegmatis(M. smegmatis) and Escherichia coli(E. coli), as shown by bacterial membrane damage and biofilm elimination. Furthermore, ultrasound-active RePy-TPE perturbed the purine metabolism of the bacteria, which disturbed the biosynthesis of DNA and energy metabolism, eventually reducing the vitality of bacteria. This article provides a novel strategy for the development of ultrasound-active metal-based antibiotics.