Activation of microbubbles by low-intensity pulsed ultrasound enhances the cytotoxicity of curcumin involving apoptosis induction and cell motility inhibition in human breast cancer MDA-MB-231 cells

A vortex-based hydrodynamic cavitation manufacturing platform to generate albumin microbubbles for delivery of chemotherapies to cancerous tumours

A novel approach was developed to create stable protein-based microbubbles using a vortex-driven hydrodynamic cavitation device. Such microbubbles, tiny gas-filled spheres, combined with ultrasound, can enhance drug uptake leading to inhibition of cancerous cell growth, boosting the effectiveness of anti-cancer drug molecules. The optimal conditions for the fabrication of stable bovine serum albumin (BSA) microbubbles were found to be a 15 wt% bovine serum albumin (BSA) solution at 60 °C with a pH of 6 and an ionic strength of 1.0 M. This resulted in stable BSA microbubbles with an approximate diameter of 7 μm. Curcumin-encapsulated BSA microbubbles (CBMs, 63 ± 1 μM curcumin per 101⁰ microbubbles) were created using these optimised fabrication parameters as a model system for delivering chemotherapeutic agents. The maximum percentage of curcumin release from the CBMs into phosphate buffered saline with sonication (85 %) was significantly greater than without sonication (24 %). These microbubbles were then tested to assess their effectiveness in delivering curcumin to triple-negative breast cancer cells (MDAMB-231) using a cell-to-MB ratio of 1:100, an ultrasound intensity of 0.5 W/cm2, and an ultrasound exposure time of 10 s to maximise uptake. Kinetic studies demonstrated a significant enhancement in the uptake of curcumin by MDAMB-231 cells when encapsulated into the microbubbles with ultrasound application. A substantial reduction in cellular proliferation was observed in both 2D cell culture and 3D tumour spheroid models when MDAMB-231 cells were exposed to microbubbles loaded with curcumin and ultrasound was applied. The vortex-based hydrodynamic cavitation device successfully generated curcumin loaded microbubbles with a long shelf life (120 days at 4 °C), mild preparation conditions, and enhanced uptake into cancerous tumour spheroid models. This data demonstrates the potential of this device for the commercial manufacture of drug loaded microbubble-based delivery systems.

Mechanosensitive ion channels in apoptosis and ferroptosis: focusing on the role of Piezo1

Mechanosensitive ion channels sense mechanical stimuli applied directly to the cellular membranes or indirectly through their tethered components, provoking cellular mechanoresponses. Among others, Piezo1 mechanosensitive ion channel is a relatively novel Ca2+-permeable channel that is primarily present in non-sensory tissues. Recent studies have demonstrated that Piezo1 plays an important role in Ca2+-dependent cell death, including apoptosis and ferroptosis, in the presence of mechanical stimuli. It has also been proven that cancer cells are sensitive to mechanical stresses due to higher expression levels of Piezo1 compared to normal cells. In this review, we discuss Piezo1-mediated cell death mechanisms and therapeutic strategies to inhibit or induce cell death by modulating the activity of Piezo1 with pharmacological drugs or mechanical perturbations induced by stretch and ultrasound. [BMB Reports 2023; 56(3): 145-152].

Mechanosensitive ion channels in apoptosis and ferroptosis: focusing on the role of Piezo1

Mechanosensitive ion channels sense mechanical stimuli applied directly to the cellular membranes or indirectly through their tethered components, provoking cellular mechanoresponses. Among others, Piezo1 mechanosensitive ion channel is a relatively novel Ca2+-permeable channel that is primarily present in non-sensory tissues. Recent studies have demonstrated that Piezo1 plays an important role in Ca2+-dependent cell death, including apoptosis and ferroptosis, in the presence of mechanical stimuli. It has also been proven that cancer cells are sensitive to mechanical stresses due to higher expression levels of Piezo1 compared to normal cells. In this review, we discuss Piezo1-mediated cell death mechanisms and therapeutic strategies to inhibit or induce cell death by modulating the activity of Piezo1 with pharmacological drugs or mechanical perturbations induced by stretch and ultrasound. [BMB Reports 2023; 56(3): 145-152].

Human clinical trial using diagnostic ultrasound and microbubbles to enhance neoadjuvant chemotherapy in HER2- negative breast cancer

Background

In vivo and in vitro experiments have demonstrated that diagnostic ultrasound combined with microbubbles (USMB) can enhance tumor chemotherapy, but few clinical studies have explored the effect of USMB in human HER2-negative breast cancer. We aimed to compare USMB combined with neoadjuvant chemotherapy (NAC) with NAC alone in the treatment of human HER2-negative breast cancer.

Methods

Patients (n=10) enrolled in the study were treated with TAC (taxane – (docetaxel), anthracycline – (epirubicin or doxorubicin liposomes), and cyclophosphamide) and ultrasound using a commercial clinical ultrasound scanner for 20 min after each chemotherapy session, followed by intermittent injections of SonoVue^® to induce sonoporation and enhance therapeutic efficacy. Contrast-enhanced ultrasound (CEUS) was used to record tumor perfusion before and after ultrasound treatment.

Results

After completion of chemotherapy, the maximum tumor diameter of patients in the combined treatment group (n=10) was significantly smaller than that in the control group (n=16) (p=0.017). Although the combined treatment group had higher overall response and clinical benefit rates than those in the control group, there was no statistically significant difference in RECIST between the combined treatment group and the control groups (p=0.590). More patients in the combination therapy group achieved pathologic complete response than in the control group (p=0.014). For combined treatment, CEUS revealed that the peak intensity, mean transit time, and area under the curve were higher after treatment than before treatment (p<0.001, p<0.001, p=0.003, respectively). Combined therapy did not cause additional toxicity or increase side effects.

Conclusion

USMB and chemotherapy can be combined in a clinical setting using commercially available equipment, without additional toxicity, and may improve the efficacy of NAC in HER2-negative breast cancer.

Ethnomedicinal uses of Indian spices used for cancer treatment: A treatise on structure-activity relationship and signaling pathways

Cancer is among the major cause of demise worldwide. Though the array of anticancer chemical medications is available but unfortunately, they are also associated with negative health effects. The invaluable therapeutic potential of spices makes them an integral part of our daily diet. Therefore, the present work focuses on the traditional uses of 46 spices and the phytochemical analysis of 31 spices. Out of them, only 29 spices are explored for their cytotoxicity against different cancer cell lines. The pre-clinical and clinical anticancer studies of spices along with their toxicity, mechanism of actions like Wnt/β-catenin, phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR), JAK/STAT, mitogen-activated protein kinase (MAPK), Notch-mediated pathways and Quantitative structure-activity relationship (QSAR) studies were also focused. Curcumin was found as one of the most explored bioactive in every aspect such as in-vitro, in-vivo, clinical as well as SAR anticancer studies while some other bioactive such as 1,8-Cineole, trans-Anethole, Diosgenin, Trigonelline are either unexplored or least explored for their clinical and SAR studies. In fact, traditional medicinal uses of spices also provide solid shreds of evidence for the new leads towards the invention of novel anticancer agents. Therefore, further research can be designed for the anticancer marketed formulation from spices after having their placebo and related toxicological data.

Mechanosensitive channel Piezo1 induces cell apoptosis in pancreatic cancer by ultrasound with microbubbles

Ultrasound (US), as a safe and non-invasive tool, has drawn researchers' attention to treat pancreatic ductal adenocarcinoma (PDAC). Piezo1, a mechanosensitive channel, can be activated by various mechanical stimuli. In this study, we tested the expression of Piezo1 in PDAC cell lines and tissues, and cell apoptosis in vitro and in vivo with siRNA, a lentivirus system, and a subcutaneous xenograft tumor-bearing model under the condition of US with microbubbles (MBs). We found that Piezo1 was highly expressed in PDAC cells; it was activated by US with MBs and was closely related to the apoptosis of PDAC cell lines and tumors. This study highlighted the idea of utilizing the high expression of Piezo1 in PDAC and US with MBs to provide a non-invasive strategy for the treatment of PDAC from the aspect of mechanotransduction.

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Mechanosensitive channel Piezo1 is highly expressed in pancreatic cancer cells

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Ultrasound with microbubbles induces apoptosis of pancreatic cancer cells

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Piezo1 is activated by ultrasound with microbubbles and mediates calcium influx

Sonodynamic therapy: Ultrasound parameters and in vitro experimental configurations

Sonodynamic therapy (SDT) is a new therapeutic modality for noninvasive cancer treatment based on the association of ultrasound and sonosensitizer drugs. Up to date, there is not a consensus on the standardization of the experimental conditions for the in vitro studies to correctly assess cell viability during SDT. Therefore, this review article mainly describes how the main ultrasound parameters and experimental setups of ultrasound application in vitro studies can influence the SDT bioeffects/response. The sonodynamic action is impacted by the combination of frequency, intensity, duty cycle, and ultrasound application time. The variation of experimental setups in cell culture, such as the transducer position, cell-transducer distance, coupling medium thickness, or type of culture, also influences the sonodynamic response. The intensity, duty cycle, and sonication duration increase cytotoxicity and reactive oxygen species production. For similar ultrasound parameters, differences in the experimental configuration impact cell death in vitro. Four main experimental setups are used to assess for SDT in cell culture (i) a planar transducer placed directly in contact with the bottom of the culture microplate; (ii) microplate positioned in the transducer's far-field using a water tank; (iii) sealed cell culture tubes immersed in water away from the transducer; and (iv) transducer dipped directly into the well with cell culture. Because of the significant variations in the experimental setups, sonodynamic response can significantly vary, and the translation of these results for in vivo experimentation is difficult. Therefore, a well-designed and detailed in vitro experimental setup is vital for understanding the interactions among the biological medium, the sonosensitizer, and the ultrasound for the in vitro to in vivo translation in SDT.

Sonoporation: Underlying Mechanisms and Applications in Cellular Regulation

Ultrasound combined with microbubble-mediated sonoporation has been applied to enhance drug or gene intracellular delivery. Sonoporation leads to the formation of openings in the cell membrane, triggered by ultrasound-mediated oscillations and destruction of microbubbles. Multiple mechanisms are involved in the occurrence of sonoporation, including ultrasonic parameters, microbubbles size, and the distance of microbubbles to cells. Recent advances are beginning to extend applications through the assistance of contrast agents, which allow ultrasound to connect directly to cellular functions such as gene expression, cellular apoptosis, differentiation, and even epigenetic reprogramming. In this review, we summarize the current state of the art concerning microbubble‐cell interactions and sonoporation effects leading to cellular functions.

Effects of Cytotoxic T Lymphocyte-Associated Antigen 4 Immunoglobulin Combined with Microbubble-Mediated Irradiation on Hemodynamics of the Renal Artery in Rats with Diabetic Nephropathy

Cytotoxic T lymphocyte-associated antigen 4 immunoglobulin (CTLA-4-Ig) can inhibit the effect of B7-1 and improve renal hemodynamics in rats with diabetic nephropathy (DN). Nevertheless, a strategy that could increase the permeation of CTLA-4-Ig through endothelial cells and basement membrane remains to be discovered. We investigated the effect of CTLA-4-Ig combined with microbubble-mediated irradiation on the hemodynamics of renal arteries in DN rats. Rats were treated with CTLA-4-Ig and/or microbubble exposure. After 8 wk of intervention, color Doppler ultrasonography was used to detect peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (MV), systolic acceleration (SAC), pulsatility index (PI) and resistance index (RI) of the renal artery trunk. The CTLA-4-Ig + microbubble exposure group exhibited significantly higher PSV, EDV and MV than the CTLA-4-Ig group, which had significantly higher values than the non-intervention group. The CTLA-4-Ig + microbubble exposure group exhibited significantly lower SAC, PI and RI than the CTLA-4-Ig group, which had significantly lower values than the non-intervention group. Our results indicate that both CTLA-4-Ig and CTLA-4-Ig + microbubble exposure can reduce the blood flow resistance and improve the blood flow velocity of renal arteries in rats. Moreover, the effect of CTLA-4-Ig + microbubble exposure is better than that of CTLA-4-Ig alone. Our study provides a new, effective and non-invasive strategy for the treatment of DN.

Low Dosed Curcumin Combined with Visible Light Exposure Inhibits Renal Cell Carcinoma Metastatic Behavior In Vitro

Recent documentation shows that a curcumin-induced growth arrest of renal cell carcinoma (RCC) cells can be amplified by visible light. This study was designed to investigate whether this strategy may also contribute to blocking metastatic progression of RCC. Low dosed curcumin (0.2 µg/mL; 0.54 µM) was applied to A498, Caki1, or KTCTL-26 cells for 1 h, followed by exposure to visible light for 5 min (400–550 nm, 5500 lx). Adhesion to human vascular endothelial cells or immobilized collagen was then evaluated. The influence of curcumin on chemotaxis and migration was also investigated, as well as curcumin induced alterations of α and β integrin expression. Curcumin without light exposure or light exposure without curcumin induced no alterations, whereas curcumin plus light significantly inhibited RCC adhesion, migration, and chemotaxis. This was associated with a distinct reduction of α3, α5, β1, and β3 integrins in all cell lines. Separate blocking of each of these integrin subtypes led to significant modification of tumor cell adhesion and chemotactic behavior. Combining low dosed curcumin with light considerably suppressed RCC binding activity and chemotactic movement and was associated with lowered integrin α and β subtypes. Therefore, curcumin combined with visible light holds promise for inhibiting metastatic processes in RCC.

New Aspects of Ultrasound-Mediated Targeted Delivery and Therapy for Cancer

Ultrasound-mediated targeted delivery (UMTD), a novel delivery modality of therapeutic materials based on ultrasound, shows great potential in biomedical applications. By coupling ultrasound contrast agents with therapeutic materials, UMTD combines the advantages of ultrasound imaging and carrier, which benefit deep tissue penetration and high concentration aggregation. In this paper we introduced recent advances in ultrasound contrast agents and applications in tumor therapy. Ultrasound contrast agents were categorized by their functions, mainly including thermosensitive, pH-sensitive and photosensitive ultrasound contrast agents. The various applications of UMTD in tumor treatment were summarized as follows: drug therapy, transfection of anti-oncogene, RNA interference, vaccine immunotherapy, monoclonal antibody immunotherapy, adoptive cellular immunotherapy, cytokine immunotherapy, and so on. In the end, we elaborated on the current challenges and provided perspectives of UMTD for clinical applications.

Effect of drug-loaded microbubbles combined with ultrasound on the apoptosis of cancer cells and the expression of Bax and Bcl-2 in a rabbit VX2 liver tumor model

The aim of the present study was to investigate whether the use of drug-loaded microbubbles combined with ultrasound promotes the apoptosis of cancer cells by regulating B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax) expression. Adriamycin-loaded PLGA nanoparticles (ADM-NP) were fabricated using a modified emulsification process. Lipid microbubbles (NH₂-MB) were prepared by mechanical vibration. The carboxyl groups of ADM-NP and NH₂-MB underwent a condensation reaction after 48 h, and adriamycin-loaded PLGA nanoparticles microbubble complexes (ADM-NMC) were obtained. High-performance liquid chromatography demonstrated that the entrapment efficiency and drug loading of ADM-NMC were 85.32 ± 5.41% and 7.91 ± 0.27%, respectively. The VX2 liver cancer model was established in 30 New Zealand rabbits, which were subsequently divided into three groups (n=10): a control group that received 5 ml of saline, an ADM-NP group that received 5 ml of ADM-NP and an ADM-NMC group that received 5 ml of ADM-NMC. Rabbits in the ADM-NP and ADM-NMC groups underwent irradiation 120 s with low frequency ultrasound (1 MHz, 0.5 W/cm²) for 120 s following injection. The echogenicity of tumors markedly increased following ADM-NP and ADM-NMC treatment. Staining with hematoxylin and eosin demonstrated that the tumor shape became more normal in the ADM-NP and ADM-NMC groups compared with the control group. Immunohistochemical staining and Western blotting determined that the expression of Bax increased and the expression of Bcl-2 decreased following treatment with ADM-NP and ADM-NMC. Cancer cell apoptosis was detected by flow cytometry and it was determined that apoptosis significantly increased following treatment with ADM-NP and ADM-NMC (P<0.01). Therefore, the present study demonstrated that the use of drug-loaded microbubbles combined with ultrasound may enhance the efficiency of tumor inhibition. This may be due to the promotion of cancer cell apoptosis via regulation of Bax and Bcl-2 expression.

The reversal of MRP1 expression induced by low-frequency and low-intensity ultrasound and curcumin mediated by VEGF in brain glioma

Purpose: To explore the effect of curcumin and low-frequency and low-intensity ultrasound (LFLIU) on C6 and U87 cell, and whether LFLIU could inhibit multidrug resistance protein 1 (MRP1) by increasing the sensitivity of curcumin via vascular epithelial growth factor (VEGF)/PI3K/Akt signaling pathway targeting.

Methods: C6 and U87 cells were treated with various doses of curcumin and/or different intensities of LFLIU for 60 s. After 24 hrs, the effects of curcumin and/or LFLIU on the proliferation of C6 and U87 cells were examined. Real-time PCR and western blot analysis were used to detect the expression of VEGF and MRP1 at both mRNA and protein levels. The expression of MRP1 in C6 and U87 cells was also determined following stimulation with recombinant human VEGF and/or LY294002.

Results: Curcumin and LFLIU inhibited the proliferation of glioma cells in an intensity- or dose-dependent manner. Furthermore, survivin was significant after combined treatment compares with that of curcumin or LFLIU treatment alone. VEGF and MRP1 were highly expressed in C6 and U87 cells, curcumin and LFLIU alone or in combination could decrease the expression of both VEGF and MRP1. MRP1 expression was down-regulated following LY294002 treatment, which blocked after exposure to VEGF.

Conclusion: The synergistic effects, such as a higher inhibition rate, and lower expressions of MRP1 and VEGF, of combined curcumin and LFLIU against glioma was much better than that of a single treatment. The down-regulation of MRP1 may be related with the VEGF/PI3K/Akt pathway in glioma.

Microbubble-Mediated Enhanced Delivery of Curcumin to Cervical Cancer Cells

The major bottleneck in the current chemotherapy treatment of cancer is the low bioavailability and high cytotoxicity. Targeted delivery of drug to the cancer cells can reduce the cytotoxicity and increase the bioavailability. In this context, microbubbles are currently being explored as drug-delivery vehicles to effectively deliver drug to the tumors or cancerous cells. Microbubbles when used along with ultrasound can enhance drug uptake and inhibit the growth of tumor cells. Several potential anticancer molecules exhibit poor water solubility, which limits their use in therapeutic applications. Such poorly water soluble molecules can be coadministered with microbubbles or encapsulated within or loaded on the microbubbles surface, to enhance the effectiveness of these molecules against cancer cells. Curcumin is one of such potential anticancer molecules obtained from the rhizome of herbal spice, turmeric. In this work, curcumin-loaded protein microbubbles were synthesized and examined for effective in vitro delivery of curcumin to HeLa cells. Microbubbles in the size range of 1-10 μm were produced using perfluorobutane as core gas and bovine serum albumin (BSA) as shell material and were loaded with curcumin. The amount of curcumin loaded on the microbubble surface was estimated using UV-vis spectroscopy, and the average curcumin loading was found to be ∼54 μM/10⁸ microbubbles. Kinetics of in vitro curcumin release from microbubble surface was also estimated, where a 4-fold increase in the rate of curcumin release was obtained in the presence of ultrasound. Sonication and incubation of HeLa cells with curcumin-loaded BSA microbubbles enhanced the uptake of curcumin by ∼250 times. Further, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay confirmed ∼71% decrease in cell viability when HeLa cells were sonicated with curcumin-loaded microbubbles and incubated for 48 h.

Apatinib-loaded lipid nanobubbles combined with ultrasound-targeted nanobubble destruction for synergistic treatment of HepG2 cells in vitro

Purpose

Apatinib, an oral small-molecule antiangiogenetic medicine, is used to treat patients with advanced hepatocellular carcinoma. However, its systemic toxic side effects cannot be ignored. The ultrasound (US)-targeted nanobubble destruction technology can minimize systemic drug exposure and maximize therapeutic efficacy. The aim of this study was to develop novel GPC3-targeted and drug-loaded nanobubbles (NBs) and further assess the associated therapeutic effects on hepatocellular carcinoma cells in vitro.

Materials and methods

Apatinib-loaded NBs were prepared by a mechanical vibration method. GPC3, a liver tumor homing peptide, was coated onto the surface of apatinib-loaded NBs through biotin–avidin interactions to target liver cancer HepG2 cells. The effects of different treatment groups on cell proliferation, cell cycle, and apoptosis of HepG2 cells were tested.

Results

The NBs could achieve 68% of optimal drug encapsulation. In addition, ligand binding assays demonstrated that attachment of targeted NBs to human HepG2 liver cancer cells was highly efficient. Furthermore, cell proliferation assays indicated that the antiproliferative activities of GPC3-targeted and apatinib-loaded NBs in combination with US (1 MHz, 1 W/cm², 30 s) were, respectively, 44.11%±2.84%, 57.09%±6.38%, and 67.51%±2.89% after 24, 48, and 72 h of treatment. Treatment with GPC3-targeted and apatinib-loaded NBs also resulted in a higher proportion of cells in the G1 phase compared with other treatment groups such as apatinib only and nontargeted apatinib-loaded NBs when US was utilized.

Conclusion

US-targeted and drug-loaded nanobubble destruction successfully achieved selective growth inhibition and apoptosis in HepG2 cells in vitro. Therefore, GPC3-targeted and apatinib-loaded NBs can be considered a novel chemotherapeutic approach for treating liver cancer in combination with US.

Curcumin reduces mitomycin C resistance in breast cancer stem cells by regulating Bcl-2 family-mediated apoptosis

Background

Curcumin, a natural compound derived from the turmeric rhizome Curcuma longa Linn, has anticancer and chemoresistance reduction biological activities. We evaluated the efficacy of curcumin in sensitizing chemotherapy drugs through regulation of Bcl-2-mediated apoptosis in breast cancer stem-like cells (BCSCs).

Methods

Cell survival was measured using MTT assay. Apoptosis-related proteins were observed using western blot analysis. Apoptosis was detected with flow cytometric analysis and by Hoechst 33258 staining. The mitochondrial membrane potential was observed with flow cytometric analysis.

Results

The ability of BCSCs to propagate decreased gradually along the passages and was completely lost at the fifth passage [0.1 μmol/L mitomycin C (MMC) with 5 μmol/L curcumin in MCF-7 and 0.5 μmol/L MMC with 5 μmol/L curcumin in MDA-MB-231 cells]. Curcumin combined with MMC treatment significantly decreased the levels of antiapoptotic Bcl-2 and Bcl-w expression, increased the levels of proapoptotic Bax, Bak, Bad, Bik, and Bim expression, and activated caspase-3 and caspase-9 in MCF-7 BCSCs. In the presence of Bcl-2 siRNA, the apoptosis rate increased by 15% in cells treated with curcumin and MMC. The mitochondrial membrane potential decreased by approximately 20% in MCF-7 BCSCs undergoing the combination treatment of curcumin and MMC. The combination-induced decrease in Bcl-2 was regulated by the presence of the Wnt-specific inhibitor PFK115-584 and PI3k inhibitor LY294002.

Conclusions

Our study indicates that curcumin might represent a novel therapeutic agent for treating breast cancer chemoresistance induced by MMC.

Ultrasound-Responsive Polymeric Micelles for Sonoporation-Assisted Site-Specific Therapeutic Action

Targeting drug delivery remains a challenge in various disease treatment including cancer. The local drug deposit could be greatly enhanced by some external stimuli-responsive systems. Here we develop pluronic P123/F127 polymeric micelles (M) encapsulating curcumin (Cur) that are permeabilized directly by focused ultrasound, in which ultrasound triggers drug release. Tumor preferential accumulation and site-specific sonochemotherapy were then evaluated. Cur-loaded P123/F127 mixed micelles (Cur-M) exhibited longer circulating time and increased cellular uptake compared to free Cur. With the assistance of focused ultrasound treatment, Cur-M showed tumor-targeting deposition in a time-dependent manner following systemic administration. This was due to enhanced permeabilization of tumor regions and increased penetration of Cur-M in irradiated tumor cells by ultrasound sonoporation. Furthermore, Cur-M self-assembly could be regulated by ultrasound irradiation. In vitro Cur release from mixed micelles was greatly dependent on ultrasound intensity but not on duration, suggesting the cavitational threshold was necessary to initiate subsequent sonochemotherapy. In vivo site-specific drug release was demonstrated in dual-tumor models, which showed spatial-temporal release of entrapped drugs following intratumoral injection. The sonoporation-assisted site-specific chemotherapy significantly inhibited tumor growth and the decrease in tumor weight was approximately 6.5-fold more than without exposure to ultrasound irradiation. In conclusion, the established ultrasound-guided nanomedicine targeting deposit and local release may represent a new strategy to improve chemotherapy efficiency.

Microbubble-Assisted Ultrasound-Induced Transient Phosphatidylserine Translocation

Microbubble-assisted ultrasound (sonopermeabilization) results in reversible permeabilization of the plasma membrane of cells. This method is increasingly used in vivo because of its potential to deliver therapeutic molecules with limited cell damage. Nevertheless, the effects of sonopermeabilization on the plasma membrane remain not fully understood. We investigated the influence of sonopermeabilization on the transverse mobility of phospholipids, especially on phosphatidylserine (PS) externalization. We performed studies using optical imaging with Annexin V and FM1-43 probes to monitor PS externalization of rat glioma C6 cells. Sonopermeabilization induced transient membrane permeabilization, which is positively correlated with reversible PS externalization. This membrane disorganization was temporary and not associated with loss of cell viability. Sonopermeabilization did not induce PS externalization via activation of the scramblase. We hypothesize that acoustically induced membrane pores may provide a new pathway for PS migration between both membrane leaflets. During the membrane-resealing phase, PS asymmetry may be re-established by amino-phospholipid flippase activity and/or endocytosis, along with exocytosis processes.

Challenges for drug discovery and development in China

INTRODUCTION

The drug development industry is restructuring worldwide in terms of the research and development process. As with pharmaceuticals in the west, China faces major challenges for drug discovery and development. Areas covered: In this review, the authors discuss anti-cancer, anti-allergy, anti-infectious, and proprietary Chinese Medicines (pCM) for various chronic diseases (such as the allergic diseases: eczema, asthma and allergic rhinitis), which remain the contemporary therapeutic strategies that are being explored and developed. Drug transporters, disease specific biomarkers, pharmacophores, bioactive natural products and pharmacogenetics are some aspects of research technologies. Proprietary Chinese medicine remains one of the most popular strategies. There is however the issue of good research documentation of efficacy versus adverse effects. China has a complex healthcare system involving a large patient pool. Expert opinion: Various factors can impact drug development in China including the concurrent use of both western and Chinese medicines, pharmacogenetic variances, lack of multidisciplinary team impact on disease management and drug safety. China may adopt the current development of big data analysis in other countries such as UK and US to build and centralize a nationwide database for better monitoring and clinical evaluation to provide more efficient care at a lower cost.