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.

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.

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.

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.

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.

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.

声动力疗法联合高热疗法诱导胶质瘤细胞凋亡

目的探讨声动力疗法(sonodynamic therapy,SDT)联合高热疗法(hyperthermotherapy,HT)的抗胶质瘤作用及可能机制。方法体外培养胶质瘤细胞株SNB19、U87MG,分为对照组、HT组、SDT组与SDT+HT组。应用阿尔玛蓝实验评估肿瘤细胞增殖能力,流式细胞术分析细胞凋亡率、线粒体膜电位和细胞内活性氧生成,Western blot法检测细胞凋亡相关蛋白表达情况。结果与SDT组比较,SDT+HT组抑制胶质瘤细胞增殖,与5-氨基乙酰丙酸(5-ALA)浓度、超声照射时间和HT温度呈正相关(均P<0.05),并伴随细胞活力下降的典型形态学变化。较低剂量HT(42℃作用15min)可明显促进SDT介导细胞内活性氧生成增多,线粒体膜电位水平下降和细胞凋亡增加(均P<0.05)。与对照组、HT组、SDT组比较,SDT+HT组上调cleaved caspase-3、-8、-9和Bax蛋白表达,下调Bcl-2蛋白表达(均P<0.05)。结论HT能够显著促进5-ALA-SDT抑制细胞增殖、诱导细胞凋亡,进而抑制胶质瘤生长。SDT联合HT疗法是一个颇具潜力的胶质瘤治疗方法。

声动力治疗的研究进展与展望

癌症因其高发病率和致死率严重危害人类的健康。传统的癌症治疗方法,如手术、放疗和化疗等,存在创伤大、复发率高和毒副作用显著等缺点。因此开发新型的癌症治疗方法迫在眉睫。在众多新型的癌症治疗方法中,光动力治疗(Photodynamic therapy,PDT)因具有无创伤性、低耐药性、低毒性和可消灭隐形肿瘤病灶等优点受到广泛关注。但由于光源难以穿透深层组织,PDT对于深层肿瘤的治疗效果不佳。声动力治疗(Sonodynamic therapy,SDT)利用超声激活声敏剂产生活性氧(Reactive oxygen species,ROS)和碳自由基,从而诱导肿瘤细胞死亡。SDT在保留PDT所有的优点外,还能有效克服PDT组织穿透能力不足的问题,展现出广阔的临床应用前景。该综述概括了SDT可能的机制和声敏剂的类型,总结了SDT发展所面临的挑战,并展望了未来可能的发展方向。

无机纳米材料用于声动力治疗的研究进展

声动力治疗是一种新型肿瘤治疗方式,因具有非侵入性、高穿透性、高安全性、时空可控性等优点,近年来受到研究人员的广泛关注。声动力治疗依赖声敏剂在低频超声下产生的空化泡和活性氧对肿瘤组织产生化学损伤和机械损伤。现有声敏剂主要可以分为有机声敏剂、无机声敏剂和有机无机杂化声敏剂,其中无机声敏剂由于具有高超声稳定性、多功能性、易合成、易表面修饰等优点近年来广受关注。本文着重介绍了声动力治疗中化学损伤和机械损伤的产生机制,并基于声敏剂的作用机制对已有无机声敏剂的设计进行总结与展望。

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.

声动力疗法在黑色素瘤中的应用进展

随着纳米医学和纳米生物技术的快速发展,各种具有良好疗效和生物安全性的治疗方式相继出现。声动力疗法(SDT)是一种低强度超声与声敏剂相结合的治疗方法,具有穿透力强、患者依从性好、对正常组织损伤小等优点,其中声敏剂的结构和理化性质对SDT治疗效果起决定性作用。目前,SDT已应用于黑色素瘤的无创治疗,但由于肿瘤微环境中氧浓度不足以及活性氧的快速清除,单纯的SDT仍难以高效地消除肿瘤,需要与其他肿瘤纳米疗法联合以克服单一治疗模式的不足。未来,SDT将可能成为无创癌症治疗的首选方式之一。

锌基MOFs材料在肿瘤治疗领域的应用进展

金属-有机框架(MOFs)是由含氧或氮的有机配体与过渡金属通过自组装连接而形成的具有周期性网状结构的晶体材料。该类材料因具有尺寸结构可调、高孔隙率、比表面积大、低晶体密度等一系列优点,而受到多个学科研究人员的重视。其中,锌(Zn)基MOFs材料因其优越的生物相容性和易功能化修饰等特点,受到了广泛的关注。文章主要从药物递送和协同抗癌等方面总结了Zn基MOFs材料的生物应用.

基于中空复合纳米粒子的超声溶栓体系构建及效果验证

目的 评价超声辅助微泡溶栓联合声动力疗法的中空复合纳米粒子的生物安全性及体外溶栓效果,评估其治疗静脉血栓栓塞症的潜在应用价值。方法 制备氮掺杂石墨烯量子点(NGQD)和一氧化氮供体N,N’-二仲丁基-N,N’-二亚硝基-1,4-苯二胺(BNN6),BNN6负载于NGQD上,将二者复合体载入利用盐模板法制备的中空介孔二氧化硅(HMSN)中,形成纳米溶栓体系BNM;通过电镜和纳米粒度仪观察BNM的形貌、尺寸等特征;通过细胞毒性实验、活-死细胞染色及溶血实验评价纳米溶栓体系BNM的生物安全性;通过体外溶栓和纤维蛋白凝块降解评价纳米材料的体外溶栓效果。结果 与对照组相比,不同浓度的BNM对HUVECs和RAW264.7细胞的活性无影响,中低浓度BNM的溶血率未超过纳米材料溶血安全限,3个浓度的BNM对红细胞和血小板的形貌未产生明显影响,不引起血小板活化;与对照组相比,超声辅助BNM组的溶栓率随BNM浓度增加而提高,纤维蛋白网络出现空洞,荧光面积比降低。结论 本研究制备的纳米溶栓系统具有很好的生物相容性和血液安全性,可以响应超声进行溶栓,表现出优良的溶栓性能,为临床应用提供了新策略。

Newly developed gas-assisted sonodynamic therapy in cancer treatment

Sonodynamic therapy(SDT) is an emerging noninvasive treatment modality that utilizes lowfrequency and low-intensity ultrasound(US) to trigger sensitizers to kill tumor cells with reactive oxygen species(ROS).Although SDT has attracted much attention for its properties including high tumor specificity and deep tissue penetration,its anticancer efficacy is still far from satisfactory.As a result,new strategies such as gas-assisted therapy have been proposed to further promote the effectiveness of SDT.In this review,the mechanisms of SDT and gas-assisted SDT are first summarized.Then,the applications of gas-assisted SDT for cancer therapy are introduced and categorized by gas types.Next,therapeutic systems for SDT that can realize real-time imaging are further presented.Finally,the challenges and perspectives of gas-assisted SDT for future clinical applications are discussed.

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.

Platelet membrane-coated C-TiO_(2) hollow nanospheres for combined sonodynamic and alkyl-radical cancer therapy

The therapeutic efficiency of sonodynamic therapy(SDT)mainly depends on the presence of oxygen(O_(2))to generate harmful reactive oxygen species(ROS);thus,the hypoxic tumor microenvironment significantly limits the efficacy of SDT.Therefore,the development of oxygen-independent free radical generators and associated combination therapy tactics can be a promising field to facilitate the anticancer capability of SDT.In this study,a biomimetic drug delivery system(C-TiO_(2)/AIPH@PM)composed of an alkyl-radical generator(2,2′-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride,AIPH)-loaded C-TiO_(2) hollow nanoshells(HNSs)as the inner cores,and a platelet membrane(PM)as the outer shells is successfully prepared for synergistic SDT and oxygen-independent alkyl-radical therapy.The PM encapsulation can significantly prolong the blood circulation time of CTiO_(2)/AIPH@PM compared with C-TiO_(2)/AIPH while enabling C-TiO_(2)/AIPH@PM to achieve tumor targeting.C-TiO_(2)/AIPH@PM can efficiently produce ROS and alkyl radicals,which can achieve a more thorough tumor eradication regardless of the normoxic or hypoxic conditions.Furthermore,the generation of these radicals improves the efficiency of SDT.In addition,nitrogen(N_(2))produced due to the decomposition of AIPH enhances the acoustic cavitation effect and lowers the cavitation threshold,thereby enhancing the penetration of CTiO_(2)/AIPH@PM at the tumor sites.Both in vitro and in vivo experiments demonstrate that CTiO_(2)/AIPH@PM possesses good biosafety,ultrasound imaging performance,and excellent anticancer efficacy.This study provides a new strategy to achieve oxygen-independent free radical production and enhance therapeutic efficacy by combining SDT and free radical therapy.

Modulation of reactive oxygen species to enhance sonodynamic therapy

Reactive oxygen species(ROS),involving in many biological reactions,play an important role in disease treatment.Among the various ROS-based therapeutic modalities,sonodynamic therapy(SDT)stands out with its unique advantages.In turn,the SDT efficacy is mainly dependent on the ROS levels in the disease microenvironment.Therefore,in recent years,researchers have extensively investigated SDT with high ROS generation capacity.In this review,we focus on effective strategies to improve the therapeutic ef-ficiency of SDT by modulating ROS,overview the basic mechanisms of ROS generation by sonosensitizers,highlight the rational design of sonosensitizers,and summarize strategies to improve the SDT efficacy by modulating disease microenvironment.In addition,multiple ROS synergistic treatment modalities and the prospect of SDT are discussed.We believe that the understanding and exploration of SDT enhancement strategies will facilitate the clinical translation of SDT.