Nanosonosensitizers for Highly Efficient Sonodynamic Cancer Theranostics

Engineering oxygen-deficient ZrO2-x nanoplatform as therapy-activated "immunogenic cell death (ICD)" inducer to synergize photothermal-augmented sonodynamic tumor elimination in NIR-II biological window

Nano-zirconia, as an amphoteric semiconductor, has been industrially exploited in photocatalytic reactions and as piezoelectric sensors. However, its biomedical applications, especially in antitumor therapeutics, have been seldom investigated to date. Here, oxygen-deficient zirconia (ZrO_2-x)-based nanoplatform with surface PEGylation and cyclic-Arg-Gly-Asp (cRGD) peptide functionalization (ZrO_2-x@PEG/cRGD, abbreviated as ZPR) was rationally designed and established for the first time, which was utilized as therapy-activated "immunogenic cell death (ICD)" inducer to boost photothermal-augmented sonodynamic tumor elimination in NIR-II biological window. As-synthesized ZPR nanoparticles (NPs) exhibited intense optical absorbance in the wavelength range of 900-1100 nm, which endowed ZPR NPs with a photothermal conversion efficiency as high as 45.8% for photothermal therapy (PTT). Moreover, owing to the abundant surface oxygen defects, ZPR NPs can serve as a category of high-performance nano-sonosensitizer based on the strengthened separation of electron (e^-)/hole (h⁺) pairs from the energy band under external ultrasound (US) activation. More importantly, cytotoxic reactive oxygen species (ROS) generated from sonodynamic therapy (SDT) can effectively induce immunogenic cell death (ICD), which is regarded to be significant to boost systemic anti-tumor immunity for rendering a complete tumor eradication post-treatment. In vivo experiments on tumor xenografts demonstrated the high therapeutic efficacy upon photothermal-augmented sonodynamic therapy, with the aid of photoacoustic (PA) imaging navigation. Remarkably, the level of inflammatory cytokines, including type I interferon (IFN), tumor necrosis factor α (TNF-α) as well as interleukin (IL-6) were systemically upgraded after NIR-II/US irradiation, verifying the promotion of immunogenicity. Taken together, this study delivers useful insights for extending the applications of zirconia as promising translational medicine for tumor theranostics in the near future.

Hypoxia modulation by dual-drug nanoparticles for enhanced synergistic sonodynamic and starvation therapy

BACKGROUND

Sonodynamic therapy (SDT) is an emerging non-invasive therapeutic technique. SDT-based cancer therapy strategies are presently underway, and it may be perceived as a promising approach to improve the efficiency of anti-cancer treatment. In this work, multifunctional theranostic nanoparticles (NPs) were synthesized for synergistic starvation therapy and SDT by loading glucose oxidase (GOx, termed G) and 5,10,15,20-tetrakis (4-chlorophenyl) porphyrin) Cl (T (p-Cl) PPMnCl, termed PMnC) in Poly (lactic-co-glycolic) acid (PLGA) NPs (designated as MG@P NPs).

RESULTS

On account of the peroxidase-like activity of PMnC, MG@P NPs can catalyze hydrogen peroxide (H2O2) in tumor regions to produce oxygen (O2), thus enhancing synergistic therapeutic effects by accelerating the decomposition of glucose and promoting the production of cytotoxic singlet oxygen (1O2) induced by ultrasound (US) irradiation. Furthermore, the NPs can also serve as excellent photoacoustic (PA)/magnetic resonance (MR) imaging contrast agents, effectuating imaging-guided cancer treatment.

CONCLUSION

Multifunctional MG@P NPs can effectuate the synergistic amplification effect of cancer starvation therapy and SDT by hypoxia modulation, and act as contrast agents to enhance MR/PA dual-modal imaging. Consequently, MG@P NPs might be a promising nano-platform for highly efficient cancer theranostics.

A sonosensitiser-based polymeric nanoplatform for chemo-sonodynamic combination therapy of lung cancer

BACKGROUND

Lung cancer is the most common type of tumour worldwide. Its relative lethality is considerably high. However, since the tumour tissues are located deep within the human body, traditional technologies, such as photodynamic therapy, do not have the desired effect. Sonosensitisers can penetrate deeply into tissues, and sonodynamic therapy (SDT) effectively inhibits tumours by generating reactive oxygen species. Ultrasound can also penetrate deeply, with a favourable tumour inhibition effect.

RESULTS

A redox/ultrasound-responsive Rhein-chondroitin sulphate-based nano-preparation encapsulating docetaxel was fabricated. The nanoparticles displayed increased cellular uptake with quick drug release, good stability, and a monodispersed form in the physiological environment. Rhein induced apoptosis and altered mitochondrial membrane potential, which enhanced the expression of apoptosis-related proteins. SDT inhibited the metastasis and angiogenesis of cancer cells and activated anti-tumour capacity by reducing the expression of M2 macrophages.

CONCLUSIONS

The potential of Rhein for SDT was demonstrated. Production of reaction oxygen species was markedly enhanced after ultrasound treatment. The nanoplatform enhanced the synergistic anti-tumour effects of SDT and chemotherapeutic efficacy. The approach was biocompatibility. The findings could inform investigations of chemo-SDT for different cancers.

Applications of Micro/Nanotechnology in Ultrasound-based Drug Delivery and Therapy for Tumor

Ultrasound has been broadly used in biomedicine for both tumor diagnosis as well as therapy. The applications of recent developments in micro/nanotechnology promote the development of ultrasound-based biomedicine, especially in the field of ultrasound-based drug delivery and tumor therapy. Ultrasound can activate nano-sized drug delivery systems by different mechanisms for ultrasound- triggered on-demand drug release targeted only at the tumor sites. Ultrasound Targeted Microbubble Destruction (UTMD) technology can not only increase the permeability of vasculature and cell membrane via sonoporation effect but also achieve in situ conversion of microbubbles into nanoparticles to promote cellular uptake and therapeutic efficacy. Furthermore, High Intensity Focused Ultrasound (HIFU), or Sonodynamic Therapy (SDT), is considered to be one of the most promising and representative non-invasive treatment for cancer. However, their application in the treatment process is still limited due to their critical treatment efficiency issues. Fortunately, recently developed micro/nanotechnology offer an opportunity to solve these problems, thus improving the therapeutic effect of cancer. This review summarizes and discusses the recent developments in the design of micro- and nano- materials for ultrasound-based biomedicine applications.

Co-delivery of cisplatin and oleanolic acid by silica nanoparticles-enhanced apoptosis and reverse multidrug resistance in lung cancer

Multidrug resistance (MDR) of chemotherapy is one of the significant concerns in cancer therapy. Here in our study, cisplatin (DDP) and oleanolic acid (OA) were co-loaded in mesoporous silica nanoparticles (Nsi) to construct DDP/OA-Nsi and solve the DDP-resistance in lung cancer therapy. The cytotoxicity and apoptosis assays demonstrated that in DDP-resistant A549/DDP cells, the cytotoxicity of DDP/OA-Nsi was significantly higher than that of free DDP or DDP single delivery system (DDP-Nsi). The intracellular drug accumulation study revealed that the intracellular DDP concentration in the DDP/OA-Nsi group was also higher than that in free DDP and DDP-Nsi groups. In the A549/DDP xenograft tumor model, DDP/OA-Nsi showed the best anticancer effect. In summary, DDP/OA-Nsi was a promising drug delivery system to solve MDR in lung cancer therapy.

One Responsive Stone, Three Birds: Mn(III)-Hemoporfin Frameworks with Glutathione-Enhanced Degradation, MRI, and Sonodynamic Therapy

Ultrasound-driven sonodynamic therapy (SDT) catches numerous attentions for destroying deep-seated tumors, but its applications suffer from unsatisfactory therapeutic effects and metabolism. Furthermore, SDT is usually weakened by the complex tumor microenvironment, such as the overexpression of glutathione (GSH). To address these issues, Mn(III)-hemoporfin frameworks (Mn(III)-HFs) are reported as nanosonosensitizers by using biocompatible hematoporphyrin monomethyl-ether (HMME) to coordinate with Mn(III) ions. Mn(III)-HFs/PEG can react with GSH to produce Mn(II) ions and oxidized glutathione (GSSG), resulting in three fascinating features: 1) the redox reaction facilitates the decomposition of Mn(III)-HFs/PEG and then collapse of nanostructures, improving the biodegradability; 2) Mn(II) ions with five unpaired 3d-electrons exhibit better magnetic resonance imaging (MRI) ability compared to Mn(III) ions with four electrons; 3) both the depletion of endogenous GSH and the dissociated HMME boost ¹ O₂ generation ability under US irradiation. As a result, when Mn(III)-HFs/PEG dispersion is intravenously administered into mice, it exhibits high-contrast T₁ /T₂ dual-modal MRI and significant suppression for the growth rate of the deep-seated tumor. Furthermore, Mn(III)-HFs/PEG can be efficiently metabolized from the mice. Therefore, Mn(III)-HFs/PEG exhibit GSH-enhanced degradation, MRI, and SDT effects, which provide some insights on the developments of other responsive nanosonosensitizers.

Multifunctional l-arginine-based magnetic nanoparticles for multiple-synergistic tumor therapy

Tumor therapy is facing the big challenge of insufficient treatment. Here, we report high-intensity focused ultrasound (HIFU)-responsive magnetic nanoparticles based on superparamagnetic iron oxide (SPIO, Fe₃O₄ NPs) as the shell and l-arginine (LA) as the core entrapped by poly-lactide-co-glycolide (PLGA) nanoparticles (Fe₃O₄@PLGA/LA NPs) for synergistic breast cancer therapy. These NPs can significantly enhance therapeutic performance due to their enhanced accumulation and prolonged retention at the tumor site under magnetic guidance. The Fe₃O₄@PLGA/LA NPs exhibited synergistic therapeutic effects by the rational combination of HIFU-based tumor ablation and nitric oxide (NO) assisted antitumor gas therapy. Both Fe₃O₄ NPs and LA could be released rapidly under HIFU irradiation, where Fe₃O₄ NPs can promote HIFU-based tumor ablation by changing the acoustic properties of the tumor tissues and LA can spontaneously react with hydrogen peroxide (H₂O₂) in the tumor microenvironment to generate NO for gas therapy. Moreover, Fe₃O₄ NPs can react with H₂O₂ to produce highly reactive oxygen-containing species (ROS) to accelerate the oxidation of LA and the release of NO. This novel strategy showed synergistic tumor growth suppression as compared with individual HIFU therapy or gas therapy. This can be attributed to the rational design of multifunctional NPs with magnetic targeting and multi-modality imaging properties.

Synergistic agents for tumor-specific therapy mediated by focused ultrasound treatment

This minireview highlights the recent advances in the therapeutic agents that aim to provide synergistic enhancements of focused ultrasound treatment of tumors. Even though focused ultrasound therapy itself can bring therapeutic effects in cancers, many biochemical agents have been reported in the literature to enhance the treatment efficacy significantly. Until now, many mechanisms have been researched to advance the therapy, such as sonodynamic-plus-chemo-therapy, microbubble-aided therapy, localized release or delivery of nanomaterials, and multimodal image-guided therapy. Here, the novel materials adopted in each mechanism are briefly reviewed to provide a trend in the field and encourage future research towards the successful deployment of focused ultrasound therapy in real clinical environments.

Manganese porphyrin-based metal-organic framework for synergistic sonodynamic therapy and ferroptosis in hypoxic tumors

Development of efficient therapeutic strategy to incorporate ultrasound (US)-triggered sonodynamic therapy (SDT) and ferroptosis is highly promising in cancer therapy. However, the SDT efficacy is severely limited by the hypoxia and high glutathione (GSH) in the tumor microenvironment, and ferroptosis is highly associated with reactive oxygen species (ROS) and GSH depletion.

Methods: A manganese porphyrin-based metal-organic framework (Mn-MOF) was constructed as a nanosensitizer to self-supply oxygen (O₂) and decrease GSH for enhanced SDT and ferroptosis. In vitro and in vivo analysis, including characterization, O₂ generation, GSH depletion, ROS generation, lipid peroxidation, antitumor efficacy and tumor immune microenvironment were systematically evaluated.

Results: Mn-MOF exhibited catalase-like and GSH decreasing activity in vitro. After efficient internalization into cancer cells, Mn-MOF persistently catalyzed tumor-overexpressed H₂O₂ to in-situ produce O₂ to relieve tumor hypoxia and decrease GSH and GPX4, which facilitated the formation of ROS and ferroptosis to kill cancer cells upon US irradiation in hypoxic tumors. Thus, strong anticancer and anti-metastatic activity was found in H22 and 4T1 tumor-bearing mice after a single administration of Mn-MOF upon a single US irradiation. In addition, Mn-MOF showed strong antitumor immunity and improved immunosuppressive microenvironment upon US irradiation by increasing the numbers of activated CD8⁺ T cells and matured dendritic cells and decreaing the numbers of myeloid-derived suppressor cells in tumor tissues.

Conclusions: Mn-MOF holds great potential for hypoxic cancer therapy.

Investigating the performance of a novel pH and cathepsin B sensitive, stimulus-responsive nanoparticle for optimised sonodynamic therapy in prostate cancer

Nano-formulations that are responsive to tumour-related and externally-applied stimuli can offer improved, site-specific antitumor effects, and can improve the efficacy of conventional therapeutic agents. Here, we describe the performance of a novel stimulus-responsive nanoparticulate platform for the targeted treatment of prostate cancer using sonodynamic therapy (SDT). The nanoparticles were prepared by self-assembly of poly(L-glutamic acid-L-tyrosine) co-polymer with hematoporphyrin. The nanoparticulate formulation was characterized with respect to particle size, morphology, surface charge and singlet oxygen production during ultrasound exposure. The response of the formulation to the presence of cathepsin B, a proteolytic enzyme that is overexpressed and secreted in the tumour microenvironment of many solid tumours, was assessed. Our results showed that digestion with cathepsin B led to nanoparticle size reduction. In the absence of ultrasound, the formulation exhibited greater toxicity at acidic pH than at physiological pH, using the human prostate cells lines LNCaP and PC3 as targets. Nanoparticle cellular uptake was enhanced at acidic pH – a condition that was also associated with greater cathepsin B production. Nanoparticles exhibited enhanced ultrasound-induced cytotoxicity against both prostate cancer cell lines. Subsequent proof-of-concept in vivo studies demonstrated that, when ectopic human xenograft LNCaP tumours in SCID mice were treated with SDT using the systemically-administered nanoparticulate formulation at a single dose, tumour volumes decreased by up to 64% within 24 h. No adverse effects were observed in the nanoparticle-treated mice and their body weight remained stable. The potential of this novel formulation to deliver safe and effective treatment of prostate cancer is discussed.

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Digestion by cathepsin B leads to nanoparticle size reduction.

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The acidic pH facilitates improved cellular uptake of the nanoparticles.

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Ultrasound–induced cytotoxic effects were elicited only for the nanoparticle-treated prostate cancer cells.

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Sonodynamic treatment resulted in an average of 36% reduction in prostate tumour volume, within 24 h.

Increased photodynamic therapy sensitization in tumors using a nitric oxide-based nanoplatform with ATP-production blocking capability

Photodynamic therapy (PDT) efficacy in cancer cells is affected by sub-physiological hypoxia caused by dysregulated and “chaotic” tumor microvasculature. However, current traditional O₂-replenishing strategies are undergoing their own intrinsic deficiencies. In addition, resistance mechanisms activated during PDT also lead the present situation far from satisfactory.

Methods: We propose a nitric oxide (NO)-based theranostic nanoplatform by using biocompatible poly-lactic-co-glycolic acid nanoparticles (PLGA NPs) as carriers, in which the outer polymeric layer embeds chlorin e6 (Ce6) and incorporates L-Arginine (L-Arg). This nanoplatform (L-Arg@Ce6@P NPs) can reduce hyperactive O₂ metabolism of tumor cells by NO-mediated mitochondrial respiration inhibition, which should raise endogenous O₂ tension to counteract hypoxia. Furthermore, NO can also hinder oxidative phosphorylation (OXPHOS) which should cause intracellular adenosine triphosphate (ATP) depletion, inhibiting tumor cells proliferation and turning cells more sensitive to PDT.

Results: When the L-Arg@Ce6@P NPs accumulate in solid tumors by the enhanced permeability and retention (EPR) effect, locally released L-Arg is oxidized by the abundant H₂O₂ to produce NO. In vitro experiments suggest that NO can retard hypoactive O₂ metabolism and save intracellular O₂ for enhancing PDT efficacy under NIR light irradiation. Also, lower intracellular ATP hinders proliferation of DNA, improving PDT sensitization. PDT phototherapeutic efficacy increased by combining these two complementary strategies in vitro/in vivo.

Conclusion: We show that this NO-based nanoplatform can be potentially used to alleviate hypoxia and sensitize tumor cells to amplify the efficacy of phototherapy guided by photoacoustic (PA) imaging.

Red Blood Cell Membrane-Coated Silica Nanoparticles Codelivering DOX and ICG for Effective Lung Cancer Therapy

The effective chemotherapy of cancer is usually hindered by the unsatisfied cell internalization of the drug delivery systems (DDS) as well as drug resistance of cancer cells. In order to solve these dilemmas in one design, red blood cell membrane (RBM)-coated silica nanoparticles (RS) were fabricated to codeliver doxorubicin (Dox) and indocyanine green (ICG) to effectively treat the model lung cancer using photothermal-assisted chemotherapy. Our results demonstrated that the RS/I-D was the nanoparticle at around 100 nm with superior stability and biocompatibility. Especially, the photothermal effects of ICG were well preserved and could be applied to accelerate the drug release from the DDS. More importantly, the RBM modification can mediate enhanced cell internalization of drugs as compared to their free forms, which finally resulted in enhanced anticancer efficacy in Dox-resistant A549 cells (A549/Dox) both in vitro and in vivo with enhanced cell apoptosis and cell arrest.

Recent Advances in Nanomaterial-Assisted Combinational Sonodynamic Cancer Therapy

Ultrasound (US)-triggered sonodynamic therapy (SDT), as a promising noninvasive therapeutic modality, has received ever-increasing attention in recent years. Its specialized chemical agents, named sonosensitizers, are activated by low-intensity US to produce lethal reactive oxygen species (ROS) for oncotherapy. Compared with phototherapeutic strategies, SDT provides many noteworthy opportunities and benefits, such as deeper penetration depth, absence of phototoxicity, and fewer side effects. Nevertheless, previous studies have also demonstrated its intrinsic limitations. Thanks to the facile engineering nature of nanotechnology, numerous novel nanoplatforms are being applied in this emerging field to tackle these intrinsic barriers and achieve continuous innovations. In particular, the combination of SDT with other treatment strategies has demonstrated a superior efficacy in improving anticancer activity relative to that of monotherapies alone. Therefore, it is necessary to summarize the nanomaterial-assisted combinational sonodynamic cancer therapy applications. Herein, the design principles in achieving synergistic therapeutic effects based on nanomaterial engineering methods are highlighted. The ultimate goals are to stimulate the design of better-quality combined sonodynamic treatment schemes and provide innovative ideas for the perspectives of SDT in promoting its future transformation to clinical application.

A mitochondria-targeted anticancer nanoplatform with deep penetration for enhanced synergistic sonodynamic and starvation therapy

Sonodynamic therapy (SDT), as an emerging technique, gives rise to reactive oxygen species (ROS)-induced apoptosis of tumor cells. However, nonselective enrichment and unsatisfactory penetration depth of sonosensitizers in tumor tissues limit its application. In this study, we synthesized core/shell (glucose oxidase (GOx) in the core/hematoporphyrin monomethyl ether (HMME) and IR780 in the shell) structured polylactic-co-glycolic acid (PLGA) nanoparticles (NPs) with deep tumor penetration and mitochondrial targeting capability for synergistic sonodynamic and starvation therapy. After passing through the endothelial space of tumor vasculatures, by virtue of IR780, these NPs can selectively accumulate towards cancer cells/sites, especially in mitochondria and diffuse into deep tumour centres. Upon ultrasound (US) exposure, the overproduced ROS cause tumor cell apoptosis. Sonodynamic effects can be amplified by mitochondrial targeting because mitochondria are susceptible to ROS. GOx blocks glucose (energy) supply, further suppressing the growth of malignant tumors. This synergistic therapy exhibited a superb response to treatment (4.7-fold lower tumor growth in volume than the control group). In addition, these NPs also serve as excellent photoacoustic (PA)/fluorescent (FL) imaging contrast agents to simultaneously monitor and guide cancer therapy. This study paves a promising way to achieve an ideal strategy for cancer therapy.

Zinc Oxide Nanocrystals and High-Energy Shock Waves: A New Synergy for the Treatment of Cancer Cells

In the last years, different nanotools have been developed to fight cancer cells. They could be administered alone, exploiting their intrinsic toxicity, or remotely activated to achieve cell death. In the latter case, ultrasound (US) has been recently proposed to stimulate some nanomaterials because of the US outstanding property of deep tissue penetration and the possibility of focusing. In this study, for the first time, we report on the highly efficient killing capability of amino-propyl functionalized ZnO nanocrystals (ZnO NCs) in synergy with high-energy ultrasound shock waves (SW) for the treatment of cancer cells. The cytotoxicity and internalization of ZnO NCs were evaluated in cervical adenocarcinoma KB cells, as well as the safety of the SW treatment alone. Then, the remarkably high cytotoxic combination of ZnO NCs and SW was demonstrated, comparing the effect of multiple (3 times/day) SW treatments toward a single one, highlighting that multiple treatments are necessary to achieve efficient cell death. At last, preliminary tests to understand the mechanism of the observed synergistic effect were carried out, correlating the nanomaterial surface chemistry to the specific type of stimulus used. The obtained results can thus pave the way for a novel nanomedicine treatment, based on the synergistic effect of nanocrystals combined with highly intense mechanical pressure waves, offering high efficiency, deep and focused tissue penetration, and a reduction of side effects on healthy cells.

Graphene and other 2D materials: a multidisciplinary analysis to uncover the hidden potential as cancer theranostics

Cancer represents one of the main causes of death in the world; hence the development of more specific approaches for its diagnosis and treatment is urgently needed in clinical practice. Here we aim at providing a comprehensive review on the use of 2-dimensional materials (2DMs) in cancer theranostics. In particular, we focus on graphene-related materials (GRMs), graphene hybrids, and graphdiyne (GDY), as well as other emerging 2DMs, such as MXene, tungsten disulfide (WS2), molybdenum disulfide (MoS2), hexagonal boron nitride (h-BN), black phosphorus (BP), silicene, antimonene (AM), germanene, biotite (black mica), metal organic frameworks (MOFs), and others. The results reported in the scientific literature in the last ten years (>200 papers) are dissected here with respect to the wide variety of combinations of imaging methodologies and therapeutic approaches, including drug/gene delivery, photothermal/photodynamic therapy, sonodynamic therapy, and immunotherapy. We provide a unique multidisciplinary approach in discussing the literature, which also includes a detailed section on the characterization methods used to analyze the material properties, highlighting the merits and limitations of the different approaches. The aim of this review is to show the strong potential of 2DMs for use as cancer theranostics, as well as to highlight issues that prevent the clinical translation of these materials. Overall, we hope to shed light on the hidden potential of the vast panorama of new and emerging 2DMs as clinical cancer theranostics.

A sequential targeting nanoplatform for anaplastic thyroid carcinoma theranostics

Effective accumulation of nanoparticles (NPs) in tumor regions is one of the major motivations in nanotechnology research and that the establishment of an efficient targeting nanoplatform for the treatment of malignant tumors is urgently needed for theranostic applications. In this study, we engineered multifunctional sequential targeting NPs for achieving synergistic antiangiogenic photothermal therapy (PTT) and multimodal imaging-guided diagnosis for anaplastic thyroid carcinoma (ATC) theranostics. Antibody bevacizumab with an affinity towards vascular endothelial growth factor (VEGF) on the tumor cell surface was conjugated onto the surface of polymer NPs for VEGF targeting and antiangiogenic therapy. Encapsulated IR825 was employed as a photothermal agent (PTA) with a mitochondrial targeting capability, which further cascades NPs into mitochondria to enhance hyperthermic efficiency in the ablation of tumor cells. Importantly, the combination of bevacizumab and IR825 in a single nanosystem achieved desirable accumulations of NPs and that sequential targeted PTT combined with antiangiogenesis significantly promoted the therapeutic efficiency in eradicating tumors by near-infrared (NIR) laser irradiation. Furthermore, these NPs are extraordinary contrast agents for photoacoustic, ultrasound and fluorescence imaging applications, providing multimodal imaging capabilities for therapeutic monitoring and a precise diagnosis. Therefore, this multifunctional nanoplatform provides a promising theranostic strategy for extremely malignant ATC. STATEMENT OF SIGNIFICANCE: Anaplastic thyroid carcinoma (ATC), with extremely aggressive behavior, lacks a satisfactory therapeutic method and a comprehensive early diagnostic strategy. Herein, we successfully synthesized a sequential targeting nanoplatform (IR825@Bev-PLGA-PFP NPs) with theranostic function, which specifically binds to VEGF on the tumor cell surface and further cascades into mitochondria to achieve effective accumulation of NPs in the tumor regions. As a result, it solves the urgent demand for ATC detection and therapy. By breaking the limitation of traditional target, such as low efficacy and frequent recurrence as the results of low accumulation, sequential targeting combined with synergistic antiangiogenic PTT completely eradicates tumors without any residual tissue and side effect. Therefore, this strategy paves a solid way for further investigation in the theranostic progressing of ATC.

Red blood cell membrane-enveloped O2 self-supplementing biomimetic nanoparticles for tumor imaging-guided enhanced sonodynamic therapy

Non-invasive sonodynamic therapy (SDT) was developed because of its advantages of high penetration depth and low side effects; however, tumor hypoxia greatly restricts its therapeutic effect. In this study, we aimed to develop ideal O₂ self-supplementing nanoparticles for imaging-guided enhanced sonodynamic therapy of tumors with the adept coalescence of biology with nanotechnology. Methods: Based on the natural enzyme system of red blood cells (RBC), biomimetic nanoparticles (QD@P)Rs were fabricated by encapsulating Ag₂S quantum dots (QD) in RBC vesicle membranes. The anti-tumor drug PEITC was employed to increase the intracellular H₂O₂ concentration in tumor cells. Results: In vitro and in vivo experiments demonstrated excellent biocompatibility and prolonged blood circulation of (QD@P)Rs. Following oral administration of PEITC in mice to improve the H₂O₂ concentration, the enzyme in the nanoprobe catalyzed endogenous H₂O₂ to increase O₂ content and effectively alleviate tumor hypoxia. Triggered by ultrasound under the guidance of fluorescence imaging, (QD@P)Rs generated reactive oxygen species (ROS) to induce tumor cell death, and the increased content of O₂ significantly enhanced the effect of SDT. Conclusion: Ag₂S QDs were used, for the first time, as a sonosensitizer in the SDT field. In this study, we integrated the advantages of the natural enzyme system and SDT to develop a novel approach for effective non-invasive treatment of cancer.

Multifunctional sonosensitizers in sonodynamic cancer therapy

Phototherapy, including photodynamic therapy and photothermal therapy, has the potential to treat several types of cancer.

An Ultrasound Activated Vesicle of Janus Au-MnO Nanoparticles for Promoted Tumor Penetration and Sono-Chemodynamic Therapy of Orthotopic Liver Cancer

Sonodynamic therapy (SDT) has the advantages of high penetration, non-invasiveness, and controllability, and it is suitable for deep-seated tumors. However, there is still a lack of effective sonosensitizers with high sensitivity, safety, and penetration. Now, ultrasound (US) and glutathione (GSH) dual responsive vesicles of Janus Au-MnO nanoparticles (JNPs) were coated with PEG and a ROS-sensitive polymer. Upon US irradiation, the vesicles were disassembled into small Janus Au-MnO nanoparticles (NPs) with promoted penetration ability. Subsequently, GSH-triggered MnO degradation simultaneously released smaller Au NPs as numerous cavitation nucleation sites and Mn²⁺ for chemodynamic therapy (CDT), resulting in enhanced reactive oxygen species (ROS) generation. This also allowed dual-modality photoacoustic imaging in the second near-infrared (NIR) window and T₁ -MR imaging due to the released Mn²⁺ , and inhibited orthotopic liver tumor growth via synergistic SDT/CDT.

A two-step precise targeting nanoplatform for tumor therapy via the alkyl radicals activated by the microenvironment of organelles

With the in-depth research of organelles, the microenvironment characteristics of their own, such as the acid environment of lysosomes and the high temperature environment of mitochondria, could be used as a natural and powerful condition for tumor therapy. Based on this, we constructed a two-step precise targeting nanoplatform which can realize the drug release and drug action triggered by the microenvironment of lysosomes (endosomes) and mitochondria, respectively. To begin with, the mesoporous silica nanoparticles (MSNs) were modified with triphenylphosphonium (TPP) and loaded with 2,2'-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIPH). Then, folic acid (FA) targeted pH-sensitive liposomes containing docetaxel (Lipo/DTX-FA) were prepared by thin-film dispersion method, and the core-shell AIPH/MSN-TPP@Lipo/DTX-FA nanoparticles were constructed by self-assembly during the hydration of the liposomes. When this nanoplatform entered into the tumor cells through FA receptor-mediated endocytosis, the pH-sensitive liposomes were destabilized in the lysosomes, resulting in the release of DTX and AIPH/MSN-TPP nanoparticles. After that, AIPH was delivered to mitochondria by AIPH/MSN-TPP, and the alkyl radicals produced by AIPH under the high temperature environment can cause oxidative damage to mitochondria. Not only that, the DTX could enhance the anti-tumor effect of AIPH by downregulating the expression of anti-apoptotic Bcl-2 protein. The in vitro and in vivo results demonstrate that this delivery system could induce apoptosis based on organelles' s own microenvironment, which provides a new approach for tumor therapy.

ROS-Responsive Blended Nanoparticles: Cascade-Amplifying Synergistic Effects of Sonochemotherapy with On-demand Boosted Drug Release During SDT Process

Sonodynamic therapy (SDT) not only has greater tissue-penetrating depth compared to photo-stimulated therapies, but also can also trigger rapid drug release to achieve synergistic sonochemotherapy. Here, reactive oxygen species (ROS)-responsive IR780/PTL- nanoparticles (NPs) are designed by self-assembly, which contain ROS-cleavable thioketal linkers (TL) to promote paclitaxel (PTX) release during SDT. Under ultrasound (US) stimulation, IR780/PTL-NPs produce high amounts of ROS, which not only induces apoptosis in human glioma (U87) cells but also boosts PTX released by decomposing the ROS-sensitive TL. In the U87 tumor-bearing mouse model, the IR780/PTL-NPs releases the drug at the target sites in a controlled manner upon US irradiation, which significantly inhibits tumor growth and induces apoptosis in the tumor tissues with no obvious toxicity. Taken together, the IR780/PTL-NPs are a novel platform for sonochemotherapy, and can control the spatio-temporal release of chemotherapeutic drugs during SDT.

Horizons of nanotechnology applications in female specific cancers

Female-specific cancers are the most common cancers in women worldwide. Early detection methods remain unavailable for most of these cancers, signifying that most of them are diagnosed at later stages. Furthermore, current treatment options for most female-specific cancers are surgery, radiation and chemotherapy. Although important milestones in molecularly targeted approaches have been achieved lately, current therapeutic strategies for female-specific cancers remain limited, ineffective and plagued by the emergence of chemoresistance, which aggravates prognosis. Recently, the application of nanotechnology to the medical field has allowed the development of novel nano-based approaches for the management and treatment of cancers, including female-specific cancers. These approaches promise to improve patient survival rates by reducing side effects, enabling selective delivery of drugs to tumor tissues and enhancing the uptake of therapeutic compounds, thus increasing anti-tumor activity. In this review, we focus on the application of nano-based technologies to the design of novel and innovative diagnostic and therapeutic strategies in the context of female-specific cancers, highlighting their potential uses and limitations.

Gadolinium-doped carbon dots as nano-theranostic agents for MR/FL diagnosis and gene delivery

Multi-functional carbon dots with MR/FL dual-imaging and gene delivery abilities were constructed for in vitro and in vivo applications.