Evaluation of fractionated and repeated sonodynamic therapy by using dual frequency for murine model of breast adenocarcinoma

Multi-frequency therapeutic ultrasound: A review

Focused ultrasound is a noninvasive, radiation-free and real-time therapeutic approach to treat deep-seated targets, which benefits numerous diseases otherwise requiring surgeries. Treatment efficiency is one of the key factors determining therapeutic outcomes, but improving it solely by increasing the total power can be limited by the performance of general ultrasound devices. To address this, multi-frequency therapeutic ultrasound, using additional ultrasound waves of different frequencies on top of the standard single-frequency wave, provides a promising method for treatment efficiency enhancement with limited power. Several applications and numerical works have demonstrated its superiority on treatment enhancement. This paper presents an overview of the mechanisms, implementations, applications and decisive parameters of the multi-frequency therapeutic ultrasound, which could help to pave the way for better understanding and further developing this technology in the future.

Hematoporphyrin Is a Promising Sensitizer for Dual-Frequency Sono-photodynamic Therapy in Mice Breast Cancer

Background: The combination of sonodynamic and photodynamic therapy (SPDT) may be a new hopeful non-invasive method for cancer treatment, which incorporates a combination of low-intensity ultrasound, laser radiation, and a sensitizer agent. Objectives: This study aimed at evaluating the effects of hematoporphyrin (HP)-mediated SPDT (dual-frequency ultrasound and laser radiation) in the management of mice breast adenocarcinoma. Methods: One hundred and thirty-two female mice with implanted tumors were divided into 22 groups, including sham, laser, 4 groups of dual-frequency ultrasound/laser radiation, 8 groups of HP-mediated SPDT (2.5 and 5 mg/kg), and 8 groups of HP encapsulated in mesoporous silica nanoparticles (HP-MSNs)-mediated SPDT. The sensitizer was administered by intraperitoneal injection and after a 24-hour delay, tumor grafted mice were treated with a combination of dual-frequency ultrasound and laser light. The tumor growth factors were used to assess the treatment outcome. Results: The results indicated that HP or HP-MSNs-mediated SPDT had a delaying tumor growth effect. In the groups treated with dual-frequency ultrasound and laser radiation, the maximum tumor growth inhibition (TGI) ratio was 47.5%, while the maximum TGI ratio in the SPDT groups was 61.6%. The time of T2 and T5 in the case of HP-MSNs-mediated SPDT groups was increased compared with sham and that of HP-mediated SPDT groups (P < 0.05). The inhibition ratio on tumor growth increased in all SPDT groups at 12 days after the treatment. Analysis of experimental data demonstrates that this increase was not declined and persisted over 30 days of treatment. The results indicated that SPDT is effective in relative tumor volume when compared with the sham group (339.1 ± 161 and 1510.8 ± 160, respectively). HP or HP-MSNs-mediated SPDT groups had Grade I (low), while others had Grade III (high) malignancy in the histological study of mice breast adenocarcinoma. Conclusions: The results revealed that when sensitized by dual-frequency SPDT, hematoporphyrin (with and without MSNs), has a promising effect at delaying tumor growth on mice breast cancer. Therefore, it can be appreciated that careful selection of the sensitizer with SPDT will play an eminent role in the success of cancer therapies.

Current Landscape of Sonodynamic Therapy for Treating Cancer

Simple Summary

Recently, ultrasound has advanced in its treatment opportunities. One example is sonodynamic therapy, a minimally invasive anti-cancer therapy involving a chemical sonosensitizer and focused ultrasound. The combination of the ultrasound and chemical sonosensitizer amplifies the drug’s ability to target cancer cells. Combining multiple chemical sonosensitizers with ultrasound can create a synergistic effect that could effectively disrupt tumorigenic growth, induce cell death, and elicit an immune response. This review provides an oversight of the application of this treatment to various types of cancer, including prostate cancer, glioma, and pancreatic ductal adenocarcinoma tumors.

Abstract

Recent advancements have tangibly changed the cancer treatment landscape. However, curative therapy for this dreadful disease remains an unmet need. Sonodynamic therapy (SDT) is a minimally invasive anti-cancer therapy involving a chemical sonosensitizer and focused ultrasound. A high-intensity focused ultrasound (HIFU) beam is used to destroy or denature targeted cancer tissues. Some SDTs are based on unfocused ultrasound (US). In some SDTs, HIFU is combined with a drug, known as a chemical sonosensitizer, to amplify the drug’s ability to damage cancer cells preferentially. The mechanism by which US interferes with cancer cell function is further amplified by applying acoustic sensitizers. Combining multiple chemical sonosensitizers with US creates a substantial synergistic effect that could effectively disrupt tumorigenic growth, induce cell death, and elicit an immune response. Therefore, the minimally invasive SDT treatment is currently attracting attention. It can be combined with targeted therapy (double-targeting cancer therapy) and immunotherapy in the future and is expected to be a boon for treating previously incurable cancers. In this paper, we will consider the current state of this therapy and discuss parts of our research.

Design and Challenges of Sonodynamic Therapy System for Cancer Theranostics: From Equipment to Sensitizers

As a novel noninvasive therapeutic modality combining low-intensity ultrasound and sonosensitizers, sonodynamic therapy (SDT) is promising for clinical translation due to its high tissue-penetrating capability to treat deeper lesions intractable by photodynamic therapy (PDT), which suffers from the major limitation of low tissue penetration depth of light. The effectiveness and feasibility of SDT are regarded to rely on not only the development of stable and flexible SDT apparatus, but also the screening of sonosensitizers with good specificity and safety. To give an outlook of the development of SDT equipment, the key technologies are discussed according to five aspects including ultrasonic dose settings, sonosensitizer screening, tumor positioning, temperature monitoring, and reactive oxygen species (ROS) detection. In addition, some state-of-the-art SDT multifunctional equipment integrating diagnosis and treatment for accurate SDT are introduced. Further, an overview of the development of sonosensitizers is provided from small molecular sensitizers to nano/microenhanced sensitizers. Several types of nanomaterial-augmented SDT are in discussion, including porphyrin-based nanomaterials, porphyrin-like nanomaterials, inorganic nanomaterials, and organic-inorganic hybrid nanomaterials with different strategies to improve SDT therapeutic efficacy. There is no doubt that the rapid development and clinical translation of sonodynamic therapy will be promoted by advanced equipment, smart nanomaterial-based sonosensitizer, and multidisciplinary collaboration.

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.

Sonodynamic and sono-photodynamic therapy in oncology

In the present publication, authors have analyzed the results of using sonodynamic and sono-photodynamic therapy with photosensitizing agents of various classes (hematoporphyrin, 5-aminolevulinic acid, chlorin derivatives, etc.) in experimental oncology. In a number of in vitro and in vivo studies, the high antitumor efficacy of the above treatment methods has been proven. Ultrasonic treatment with a pulse frequency of 1–3 MHz and an intensity of 0.7 to 5 W/cm2 , independently and in combination with photo-irradiation of experimental tumors, can significantly improve the cytotoxic properties of photosensitizers. This became the basisfor testing the methodsin patients with malignant neoplasms of various localizations. Scientists fromSouth-East Asia presented the preliminary results of the use of sonodynamic and sono-photodynamic therapy with photosensitizers in the treatment of malignant pathology of the mammary gland, stomach, esophagus, prostate, lung and brain. Analysis of the obtained data indicates the absence of serious adverse events and an increase in the antitumor efficacy of treatment, which included these treatment methods with chlorin-type photosensitizers. 

Sonodynamic Therapy: Advances and Challenges in Clinical Translation

Sonodynamic therapy (SDT) consists of the synergetic interaction between ultrasound and a chemical agent. In SDT, the cytotoxicity is triggered by ultrasonic stimuli, notably through cavitation. The unique features of SDT are relevant in the clinical context more than ever: the need for efficacy, accuracy, and safety while being noninvasive and preserving the patient's quality of life. However, despite the promising results of this technique, only a few clinical reports describe the use of SDT. The objective of this article is to provide an extensive overview of the clinical and preclinical research conducted in vivo on SDT, to identify the limitations, and to detail the developed strategies to overcome them.