High energy shock waves activate 5'-aminolevulinic Acid and increase permeability to Paclitaxel: antitumor effects of a new combined treatment on anaplastic thyroid cancer cells

Exploiting Shock Waves to Trigger the Anticancer Sonodynamic Activity of 5-Aminolevulinc Acid-Derived Protoporphyrin IX on In Vitro 2D and 3D Cancer Models

Sonodynamic therapy (SDT) is a noninvasive method for cancer treatment based on selective activation of a sonosensitiser by ultrasound (US), which results in the generation of reactive oxygen species (ROS) and cancer cell death. SDT uses a similar approach to photodynamic therapy (PDT), but can overcome the main drawback of PDT, i.e., poor tissue penetration of light. This research work investigated the anticancer effect of SDT on various two- (2D) and three-dimensional (3D) in vitro tumour models, using PDT as a reference treatment. Sonodynamic experiments were performed with pulsed US, specifically with shock waves (SW) and the prodrug 5-aminolevulinic acid (Ala), which is converted-at the mitochondrial level-into the sonosensitiser protoporphyrin IX (PPIX). SW-mediated PPIX sonodynamic activation resulted in a significant decrease in cell proliferation, especially on human fibrosarcoma (HT-1080) cells, where PPIX accumulation was higher compared to human melanoma (A2058) and neuroblastoma (SH-SY5 Y) cells. Moreover, SW-mediated SDT showed significant ROS generation, cell line-dependent in its amount, probably due to differences in Ala-induced PPIX synthesis. In all cancer cell lines, apoptosis was highlighted as the main cancer cell death pathway determined by SW-mediated SDT, along with significant cytochrome c release, and a consequent increase in DNA damage. The efficacy of SDT with SW and Ala in halting cancer cell proliferation was also confirmed in 3D cancer spheroids. The present study suggests that SW-mediated SDT is a valuable approach to slow down tumour proliferation, thus opening an innovative scenario in cancer treatment.

Infrasound a new weapon in cancer therapy?

BACKGROUND

Researchers take different positions when describing the effects of infrasound on the human body. Although several studies investigated the likely harmful effects of infrasound exposure from wind turbines a significant connection has not been found yet. There is evidence that infrasound interacts with cell metabolism and may disrupt cell membrane integrity.

OBJECTIVES

The suggested impairment of the cells' ultrastructure by infrasound leads to the question of whether infrasound can be therapeutically used, for instance in cancer therapy. This review provides the current state of the literature.

METHOD

Current literature on infrasound in cancer therapy including all studies with the search terms 'cancer' and 'infrasound' were identified and reviewed until the year 2020.

RESULTS

The present state of research reveals promising effects of targeted infrasound in cancer therapy. Infrasound directly affects the tumor cells' ultrastructure and seems to sensitize several types of cancer to chemotherapy, presumably due to membrane permeabilization. The application of infrasound on tumor cells without other therapeutic agents demonstrates different effects that probably depend on the type of cells, the applied frequency and sound pressure level as well as the time of exposure.

CONCLUSIONS

The mechanism of infrasound on cancer cells is not completely understood yet, hence, further studies have to be conducted to clarify the ultrastructural and metabolic changes inside the tumor cells. The development of suitable infrasound generators for the application in a clinical setting would be an important course of action.

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.

Shock wave-induced permeabilization of mammalian cells

Controlled permeabilization of mammalian cell membranes is fundamental to develop gene and cell therapies based on macromolecular cargo delivery, a process that emerged against an increasing number of health afflictions, including genetic disorders, cancer and infections. Viral vectors have been successfully used for macromolecular delivery; however, they may have unpredictable side effects and have been limited to life-threatening cases. Thus, several chemical and physical methods have been explored to introduce drugs, vaccines, and nucleic acids into cells. One of the most appealing physical methods to deliver genes into cells is shock wave-induced poration. High-speed microjets of fluid, emitted due to the collapse of microbubbles after shock wave passage, represent the most significant mechanism that contributes to cell membrane poration by this technique. Herein, progress in shock wave-induced permeabilization of mammalian cells is presented. After covering the main concepts related to molecular strategies whose applications depend on safer drug delivery methods, the physics behind shock wave phenomena is described. Insights into the use of shock waves for cell membrane permeation are discussed, along with an overview of the two major biomedical applications thereof-i.e., genetic modification and anti-cancer shock wave-assisted chemotherapy. The aim of this review is to summarize 30 years of data showing underwater shock waves as a safe, noninvasive method for macromolecular delivery into mammalian cells, encouraging the development of further research, which is still required before the introduction of this promising tool into clinical practice.

Advances in limb salvage treatment of osteosarcoma

Osteosarcoma is the most common primary malignant bone tumor; its standard treatment includes neoadjuvant chemotherapy combined with surgery. Neoadjuvant chemotherapy has significantly improved the 5-year survival and limb salvage rates in osteosarcoma since the 1870s. The survival rate of patients with limb salvage was not inferior to that of amputees, and therefore, limb salvage has become the main surgical option for patients with osteosarcoma. The 5-year survival rate for osteosarcoma has plateaued. However, new advances in limb salvage therapy in osteosarcoma, including adjuvant chemotherapy, ablation techniques, bone transport techniques, and computer navigation techniques, are now available. This report summarizes the recent advances in limb salvage therapy for osteosarcoma over the past decade.

Combining doxorubicin-nanobubbles and shockwaves for anaplastic thyroid cancer treatment: preclinical study in a xenograft mouse model

Anaplastic thyroid cancer is one of the most lethal diseases, and a curative therapy does not exist. Doxorubicin, the only drug approved for anaplastic thyroid cancer treatment, has a very low response rate and causes numerous side effects among which cardiotoxicity is the most prominent. Thus, doxorubicin delivery to the tumor site could be an import goal aimed to improve the drug efficacy and to reduce its systemic side effects. We recently reported that, in human anaplastic thyroid cancer cell lines, combining doxorubicin-loaded nanobubbles with extracorporeal shock waves, acoustic waves used in lithotripsy and orthopedics without side effects, increased the intracellular drug content and in vitro cytotoxicity. In the present study, we tested the efficacy of this treatment on a human anaplastic thyroid cancer xenograft mouse model. After 21 days, the combined treatment determined the greatest drug accumulation in tumors with consequent reduction of tumor volume and weight, and an extension of the tumor doubling time. Mechanistically, the treatment induced tumor apoptosis and decreased cell proliferation. Finally, although doxorubicin caused the increase of fibrosis markers and oxidative stress in animal hearts, loading doxorubicin into nanobubbles avoided these effects preventing heart damage. The improvement of doxorubicin anti-tumor effects together with the prevention of heart damage suggests that the combination of doxorubicin-loaded nanobubbles with extracorporeal shock waves might be a promising drug delivery system for anaplastic thyroid cancer treatment.

Targeting Taxanes to Castration-Resistant Prostate Cancer Cells by Nanobubbles and Extracorporeal Shock Waves

To target taxanes to castration-resistant prostate cancer cells, glycol-chitosan nanobubbles loaded with paclitaxel and docetaxel were constructed. The loaded nanobubbles were then combined with Extracorporeal Shock Waves, acoustic waves widely used in urology and orthopedics, with no side effects. Nanobubbles, with an average diameter of 353.3 ± 15.5 nm, entered two different castration-resistant prostate cancer cells (PC3 and DU145) as demonstrated by flow cytometry and immunofluorescence. The shock waves applied increased the amount of intracellular nanobubbles. Loading nanobubbles with paclitaxel and docetaxel and combining them with shock waves generated the highest cytotoxic effects, resulting in a paclitaxel GI₅₀ reduction of about 55% and in a docetaxel GI₅₀ reduction of about 45% respectively. Combined treatment also affected cell migration. Paclitaxel-loaded nanobubbles and shock waves reduced cell migration by more than 85% with respect to paclitaxel alone; whereas docetaxel-loaded nanobubbles and shock waves reduced cell migration by more than 82% with respect to docetaxel alone. The present data suggest that nanobubbles can act as a stable taxane reservoir in castration-resistant prostate cancer cells and shock waves can further increase drug release from nanobubbles leading to higher cytotoxic and anti-migration effect.

Shock wave-induced ATP release from osteosarcoma U2OS cells promotes cellular uptake and cytotoxicity of methotrexate

Background

Osteosarcoma is the most prevalent primary malignant bone tumor, but treatment is difficult and prognosis remains poor. Recently, large-dose chemotherapy has been shown to improve outcome but this approach can cause many side effects. Minimizing the dose of chemotherapeutic drugs and optimizing their curative effects is a current goal in the management of osteosarcoma patients.

Methods

In our study, trypan blue dye exclusion assay was performed to investigate the optimal conditions for the sensitization of osteosarcoma U2OS cells. Cellular uptake of the fluorophores Lucifer Yellow CH dilithium salt and Calcein was measured by qualitative and quantitative methods. Human MTX ELISA Kit and MTT assay were used to assess the outcome for osteosarcoma U2OS cells in the present of shock wave and methotrexate. To explore the mechanism, P2X7 receptor in U2OS cells was detected by immunofluorescence and the extracellular ATP levels was detected by ATP assay kit. All data were analyzed using SPSS17.0 statistical software. Comparisons were made with t test between two groups.

Results

Treatment of human osteosarcoma U2OS cells with up to 450 shock wave pulses at 7 kV or up to 200 shock wave pulses at 14 kV had little effect on cell viability. However, this shock wave treatment significantly promoted the uptake of Calcein and Lucifer Yellow CH by osteosarcoma U2OS cells. Importantly, shock wave treatment also significantly enhanced the uptake of the chemotherapy drug methotrexate and increased the rate of methotrexate-induced apoptosis. We found that shock wave treatment increased the extracellular concentration of ATP and that KN62, an inhibitor of P2X7 receptor reduced the capacity methotrexate-induced apoptosis.

Conclusions

Our results suggest that shock wave treatment promotes methotrexate-induced apoptosis by altering cell membrane permeability in a P2X7 receptor-dependent manner. Shock wave treatment may thus represent a possible adjuvant therapy for osteosarcoma.

Doxorubicin-Loaded Nanobubbles Combined with Extracorporeal Shock Waves: Basis for a New Drug Delivery Tool in Anaplastic Thyroid Cancer

BACKGROUND

No standard chemotherapy is available for anaplastic thyroid cancer (ATC). Drug-loaded nanobubbles (NBs) are a promising innovative anticancer drug formulation, and combining them with an externally applied trigger may further control drug release at the target region. Extracorporeal shock waves (ESWs) are acoustic waves widely used in urology and orthopedics, with no side effects. The aim of the present work was to combine ESWs and new doxorubicin-loaded glycol chitosan NBs in order to target doxorubicin and enhance its antitumor effect in ATC cell lines.

METHODS

CAL-62 and 8305C cells were treated with empty NBs, fluorescent NBs, free doxorubicin, and doxorubicin-loaded NBs in the presence or in the absence of ESWs. NB entrance was evaluated by fluorescence microscopy and flow cytofluorimetry. Cell viability was assessed by Trypan Blue exclusion and WST-1 proliferation assays. Doxorubicin intracellular content was measured by high-performance liquid chromatography.

RESULTS

Treatment with empty NBs and ESWs, even in combination, was safe, as cell viability and growth were not affected. Loading NBs with doxorubicin and combining them with ESWs generated the highest cytotoxic effect, resulting in drug GI50 reduction of about 40%. Mechanistically, ESWs triggered intracellular drug release from NBs, resulting in the highest nuclear drug content.

CONCLUSIONS

Combined treatment with doxorubicin-loaded NBs and ESWs is a promising drug delivery tool for ATC treatment with the possibility of using lower doxorubicin doses and thus limiting its systemic side effects.

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.

High energy shock waves and 5-aminolevulinic for sonodynamic therapy: effects in a syngeneic model of colon cancer

The cytotoxic effect of the natural porphyrin precursor 5-aminolevulinic acid (ALA) exposed to high energy shock waves (HESW) was investigated in vitro on DHD/K12/TRb rat colon cancer cells and in vivo on a syngeneic colon cancer model. In vitro, viable cell growth was determined by trypan blue exclusion assay and cell death was investigated by flow cytometry. ALA (50 µg/ml) and HESW (E1, EFD = 0.22 mJ/mm², 1000 shots or E2, EFD = 0.88 mJ/mm², 500 shots) showed a significant reduction of cancer cell proliferation at day 3 compared to cells exposed to ALA (p < 0.01) or HESW (p < 0.001) alone. An enhancement of necrotic and apoptotic cells was observed after combined treatment at day 1 with ALA and HESW E1 (a 3.1 and 6.4 fold increase vs ALA alone) or E2 (a 3.4 and 5.3 fold increase vs ALA alone). In vivo, apoptosis detection was carried out by TUNEL assay, the pro-apoptotic gene Bad and Bcl-2 mRNA expression was evaluated by quantitative SYBR Green real time RT-PCR and cleavage of poly(ADP-ribose)-polymerase (PARP) was investigated by Western Blotting. An enhancement of apoptosis was observed in tumour tissues after the combined treatment at day 1 with ALA (375 mg/kg i.v.) and HESW (E2) compared to that of ALA exposure alone with improved apoptotic index (a 2.0 fold increase), Bad enhanced mRNA expression (p < 0.01), Bcl-2 decreased mRNA expression (p < 0.05) and increased PARP cleavage. The interaction between HESW and ALA is then effective in inducing apoptosis on a syngeneic colon cancer model.

Cytotoxicity of Paclitaxel in biodegradable self-assembled core-shell poly(lactide-co-glycolide ethylene oxide fumarate) nanoparticles

PURPOSE

Biodegradable core-shell polymeric nanoparticles (NPs), with a hydrophobic core and hydrophilic shell, are developed for surfactant-free encapsulation and delivery of Paclitaxel to tumor cells.

METHODS

Poly (lactide-co-glycolide fumarate) (PLGF) and Poly (lactide-fumarate) (PLAF) were synthesized by condensation polymerization of ultra-low molecular weight poly(L: -lactide-co-glycolide) (ULMW PLGA) with fumaryl chloride (FuCl). Similarly, poly(lactide-co-ethylene oxide fumarate) (PLEOF) macromer was synthesized by reacting ultra-low molecular weight poly(L: -lactide) (ULMW PLA) and PEG with FuCl. The blend PLGF/PLEOF and PLAF/PLEOF macromers were self-assembled into NPs by dialysis. The NPs were characterized with respect to particle size distribution, morphology, and loading efficiency. The physical state and miscibility of Paclitaxel in NPs were characterized by differential scanning calorimetry. Tumor cell uptake and cytotoxicity of Paclitaxel loaded NPs were measured by incubation with HCT116 human colon carcinoma cells. The distribution of NPs in vivo was assessed with Apc(Min/+)mouse using infrared imaging.

RESULTS

PLEOF macromer, due to its amphiphilic nature, acted as a surface active agent in the process of self-assembly which produced core-shell NPs with PLGF/PLAF and PLEOF macromers as the core and shell, respectively. The encapsulation efficiency ranged from 70 to 56% and it was independent of the macromer but decreased with increasing concentration of Paclitaxel. Most of the PLGF and PLAF NPs degraded in 15 and 28 days, respectively, which demonstrated that the release was dominated by hydrolytic degradation and erosion of the matrix. As the concentration of Paclitaxel was increased from 0 to 10, and 40 mug/ml, the viability of HCT116 cells incubated with free Paclitaxel decreased from 100 to 65 and 40%, respectively, while those encapsulated in PLGF/PLEOF NPs decreased from 93 to 54 and 28%.

CONCLUSIONS

Groups with Paclitaxel loaded NPs had higher cytotoxicity compared to Paclitaxel directly added to the media at the same concentration. NPs acted as reservoirs to protect the drug from epimerization and hydrolysis while providing a sustained dose of Paclitaxel with time. Infrared image of the Apc(Min/+) mouse injected with NPs showed significantly higher concentration of NPs in the intestinal tissue.