Hydralazine loaded nanodroplets combined with ultrasound-targeted microbubble destruction to induce pyroptosis for tumor treatment.

Pyroptosis, a novel type of programmed cell death (PCD), which provides a feasible therapeutic option for the treatment of tumors. However, due to the hypermethylation of the promoter, the critical protein Gasdermin E (GSDME) is lacking in the majority of cancer cells, which cannot start the pyroptosis process and leads to dissatisfactory therapeutic effects. Additionally, the quick clearance, systemic side effects, and low concentration at the tumor site of conventional pyroptosis reagents restrict their use in clinical cancer therapy. Here, we described a combination therapy that induces tumor cell pyroptosis via the use of ultrasound-targeted microbubble destruction (UTMD) in combination with DNA demethylation. The combined application of UTMD and hydralazine-loaded nanodroplets (HYD-NDs) can lead to the rapid release of HYD (a demethylation drug), which can cause the up-regulation of GSDME expression, and produce reactive oxygen species (ROS) by UTMD to cleave up-regulated GSDME, thereby inducing pyroptosis. HYD-NDs combined with ultrasound (US) group had the strongest tumor inhibition effect, and the tumor inhibition rate was 87.15% (HYD-NDs group: 51.41 ± 3.61%, NDs + US group: 32.73%±7.72%), indicating that the strategy had a more significant synergistic anti-tumor effect. In addition, as a new drug delivery carrier, HYD-NDs have great biosafety, tumor targeting, and ultrasound imaging performance. According to the results, the combined therapy reasonably regulated the process of tumor cell pyroptosis, which offered a new strategy for optimizing the therapy of GSDME-silenced solid tumors.

A combination of PD-L1-targeted IL-15 mRNA nanotherapy and ultrasound-targeted microbubble destruction for tumor immunotherapy.

PD-1/PD-L1-based immune checkpoint blockade therapy has shown limited benefits in tumor patients, partially attributed to the inadequate infiltration of immune effector cells within tumors. Here, we established a nanoplatform named DPPA/IL-15 NPs to target PD-L1 for the tumor delivery of IL-15 messenger RNA (mRNA). DPPA/IL-15 NPs were endowed with ultrasound responsiveness and contrast-enhanced ultrasound (CEUS) imaging performance. They effectively protected IL-15 mRNA from degradation and specifically transfected it into tumor cells through the utilization of ultrasound-targeted microbubble destruction (UTMD). This resulted in the activation of IL-15-related immune effector cells while blocking the PD-1/PD-L1 pathway. In addition, UTMD could generate reactive oxygen species (ROS) that induce endoplasmic reticulum (ER) stress-driven immunogenic cell death (ICD), initiating anti-tumor immunity. In vitro and in vivo studies revealed that this combination therapy could induce a robust systemic immune response and enhance anti-tumor efficacy. Thus, this combination therapy has the potential for clinical translation through enhanced immunotherapy and provides real-time ultrasound imaging guidance.

CAFs targeted ultrasound-responsive nanodroplets loaded V9302 and GLULsiRNA to inhibit melanoma growth via glutamine metabolic reprogramming and tumor microenvironment remodeling.

Despite rapid advances in metabolic therapies over the past decade, their efficacy in melanoma has been modest, largely due to the interaction between cancer-associated fibroblasts (CAFs) and cancer cells to promote cancer growth. Altering the tumor microenvironment (TME) is challenging and elusive. CAFs is critical for glutamine deprivation survival in melanoma. In this research, we assembled a CAFs-targeted, controlled-release nanodroplets for the combined delivery of the amino acid transporter ASCT2 (SLC1A5) inhibitor V9302 and GLULsiRNA (siGLUL). The application of ultrasound-targeted microbubble disruption (UTMD) allows for rapid release of V9302 and siGLUL, jointly breaking the glutamine metabolism interaction between CAFs and cancer cells on one hand, on the other hand, blocking activated CAFs and reducing the expression of extracellular matrix (ECM) to facilitate drug penetration. In addition, ultrasound stimulation made siGLUL more accessible to tumor cells and CAFs, downregulating GLUL expression in both cell types. FH-V9302-siGLUL-NDs also serve as contrast-enhanced ultrasound imaging agents for tumor imaging. Our study developed and reported FH-NDs as nanocarriers for V9302 and siGLUL, demonstrating that FH-V9302-siGLUL-NDs have potential bright future applications for integrated diagnostic therapy. Graphical Abstract.

Ultrasound-Targeted Microbubble Disruption with Key Nanodroplets for Effective Ferroptosis in Triple-Negative Breast Cancer Using Animal Model.

Introduction: Triple-negative breast cancer (TNBC) is known to be the most aggressive form of breast cancer. Due to its high recurrence and mortality rates, the treatment of TNBC is a significant challenge for the medical community. Besides, ferroptosis is an emerging regulatory cell death that may provide new insights into the treatment of TNBC. As a central inhibitor of the ferroptosis process, the selenoenzyme glutathione peroxidase 4 (GPX4) is its classical therapeutic target. However, inhibition of GPX4 expression is quite detrimental to normal tissues. Ultrasound contrast agents, as an emerging visualization precision treatment, may provide a solution to the existing problem. Methods: In this study, nanodroplets (NDs) carrying simvastatin (SIM) were constructed using the homogeneous/emulsification method. Then, the characterization of SIM-NDs was systematically evaluated. Meanwhile, in this study, the ability of SIM-NDs combined with ultrasound-targeted microbubble disruption (UTMD) to initiate ferroptosis and its respective mechanisms of ferroptosis induction were verified. Finally, the antitumor activity of SIM-NDs was investigated in vitro and in vivo using MDA-MB-231 cells and TNBC animal models. Results: SIM-NDs exhibited excellent pH- and ultrasound-responsive drug release and noticeable ultrasonographic imaging ability, also showing good biocompatibility and biosafety. UTMD could promote increased intracellular reactive oxygen species and consume intracellular glutathione. However, SIM-NDs were efficiently internalized into cells under ultrasound irradiation, followed by the rapid release of SIM, which inhibited intracellular mevalonate production, and synergistically downregulated GPX4 expression, thereby promoting ferroptosis. Moreover, this combined treatment demonstrated strong antitumor ability in vitro and in vivo. Conclusion: The combination of UTMD and SIM-NDs presents a promising avenue for harnessing ferroptosis in the treatment of malignant tumors.

pH-/Redox-Responsive Nanodroplet Combined with Ultrasound-Targeted Microbubble Destruction for the Targeted Treatment of Drug-Resistant Triple Negative Breast Cancer.

Multiple drug resistance (MDR) exists in divergent cancers including triple negative breast cancer (TNBC) and partly results in the resistance to many first-line anti-cancer agents, bringing a big challenge to TNBC management. To develop novel TNBC therapeutics, in our study, a hyaluronic acid (HA)-carboxymethyl chitosan (CMC) conjugate linked via a disulfide-bond (HA-SS-CMC, HSC) was synthesized to fabricate nanodroplets (NDs). The NDs encapsulating doxorubicin (DOX) and perfluorohexane (DOX-HSC-NDs) were prepared via a homogenization/emulsification strategy and exhibited not only high biocompatibility but also noticeable tumor cell targeting ability and dual pH/redox responsiveness. Besides, DOX-HSC-NDs can be used as a contrast-enhanced ultrasound imaging agent for specific tumor imaging. DOX-HSC-NDs in combination with ultrasound targeted microbubble destruction could improve intracellular drug aggregation and retention of MDR cells and work against multiple mechanisms of drug resistance through synergistic strategies, including up-regulating the reactive oxygen species (ROS) level, promoting apoptosis, and scavenging glutathione, while reducing the expression levels of P-glycoprotein and inhibiting the epithelial-mesenchymal transition. This combination strategy showed protective effects against TNBC in both MDA-MB-231/ADR cells and tumor-bearing mice. Our study for the first time developed and reported the ultrasound-augmented HSC-NDs as the DOX nanocarrier and provided scientific evidence to support the future application of DOX-HSC-NDs as a potential TNBC therapy.

Ultrasound targeted microbubble destruction-triggered nitric oxide release via nanoscale ultrasound contrast agent for sensitizing chemoimmunotherapy.

Immunotherapy had demonstrated inspiring effects in tumor treatment, but only a minority of people could benefit owing to the hypoxic and immune-suppressed tumor microenvironment (TME). Therefore, there was an urgent need for a strategy that could relieve hypoxia and increase infiltration of tumor lymphocytes simultaneously. In this study, a novel acidity-responsive nanoscale ultrasound contrast agent (L-Arg@PTX nanodroplets) was constructed to co-deliver paclitaxel (PTX) and L-arginine (L-Arg) using the homogenization/emulsification method. The L-Arg@PTX nanodroplets with uniform size of about 300 nm and high drug loading efficiency displayed good ultrasound diagnostic imaging capability, improved tumor aggregation and achieved ultrasound-triggered drug release, which could prevent the premature leakage of drugs and thus improve biosafety. More critically, L-Arg@PTX nanodroplets in combination with ultrasound targeted microbubble destruction (UTMD) could increase cellular reactive oxygen species (ROS), which exerted an oxidizing effect that converted L-Arg into nitric oxide (NO), thus alleviating hypoxia, sensitizing chemotherapy and increasing the CD8 + cytotoxic T lymphocytes (CTLs) infiltration. Combined with the chemotherapeutic drug PTX-induced immunogenic cell death (ICD), this promising strategy could enhance immunotherapy synergistically and realize powerful tumor treatment effect. Taken together, L-Arg@PTX nanodroplets was a very hopeful vehicle that integrated drug delivery, diagnostic imaging, and chemoimmunotherapy.

Utilizing RNA nanotechnology to construct negatively charged and ultrasound-responsive nanodroplets for targeted delivery of siRNA.

Ultrasound nanodroplets (NDs) have been reported as a promising nanocarrier for siRNA delivery depending on its unique strengths of sonoporation. Presently, common means for NDs-mediated siRNA delivery is through electrostatic interaction, but challenges like cationic toxicity still exist. In this study, we demonstrated a novel strategy to construct negatively charged and ultrasound (US)-responsive O-carboxymethyl chitosan (O-CMS) NDs as a siRNA targeted delivery system through three-way junction of bacteriophage phi29 DNA packaging motor (3WJ-pRNA) nanotechnology. 39nt A10-3.2 aptamer targeting prostate specific membrane antigen (PSMA) and 21nt siRNA against cationic amino acid transporter 1 (siCAT-1) were annealed to 3WJ-pRNA scaffold via complementation with an extended sequence. The cholesterol molecule attached to one branch facilitates the 3WJ-pRNA nanoparticles anchoring onto NDs. The desired O-CMS NDs with siRNA-loading and RNA-aptamer modification (A10-3.2/siCAT-1/3WJ-NDs) were successfully prepared, which were with spherical shapes, core-shell structures and uniform in sizes (198 nm with PDI 0.3). As a main proportion of shell, O-CMC showed a certain anti-tumor effects. In vitro studies demonstrated that A10-3.2/siCAT-1/3WJ-NDs exhibited good contrast-enhanced US imaging, buffering capacity and high bio-safety, were able to deliver siCAT-1 to PSMA-overexpressed prostate cancer cells under US irradiation, thus silence the CAT-1 expression, and consequently suppressing 22RV1 cell proliferation and migration. Taken overall, our findings provide a promising strategy to develop negatively charged and US-responsive NDs for tumor-targeted siRNA delivery.

Dual-responsive nanodroplets combined with ultrasound-targeted microbubble destruction suppress tumor growth and metastasis via autophagy blockade.

The inhibition of autophagy is a feasible clinical strategy in tumor therapy. Traditional autophagy inhibitors are limited in clinical tumor therapy due to nonspecific biodistribution, systemic toxicity and limited antitumor effect. Herein, the autophagy inhibitor hydroxychloroquine (HCQ)-loaded nanodroplets (NDs) are synthesized to overcome these drawbacks. HCQ-NDs are endowed with endogenous pH- and exogenous ultrasound-responsive drug release and contrast enhanced ultrasound imaging performance. The combined application of ultrasound-targeted microbubble destruction (UTMD) and HCQ-NDs can severely break the homeostasis of tumor cells, simultaneously releasing HCQ rapidly to block autophagic flux and thus abolish the cytoprotective function. This strategy presents strong synergistic antitumor efficacy with the tumor growth inhibition value of 80.02% and synchronously inhibits tumor lung metastasis by inhibition of MMP2 and MMP9 production, eventually leading to tumor suppression. In addition, HCQ-NDs show excellent tumor-targeting, biocompatibility, biosafety and contrast-enhanced ultrasound imaging properties. Based on the above findings, this combined strategy rationally regulates the autophagic process of tumor cells and could be instructive for the design of clinical treatment modalities.

GRP78-targeted and doxorubicin-loaded nanodroplets combined with ultrasound: a potential novel theranostics for castration-resistant prostate cancer.

The construction of multifunctional oncotherapy nanoplatforms that combine diagnosis and treatment remains challenging. Nanodroplets (NDs), which simultaneously enhance ultrasound imaging and therapeutic effects, are a potential strategy for non-invasive drug delivery. To achieve the goals of precise medicine, novel SP94 peptide-modified and doxorubicin-loaded ultrasonic NDs (SP94-DOX-NDs) for castration-resistant prostate cancer (CRPC) targeting and treatment were constructed in this study. The characteristics, contrast-enhanced ultrasound imaging (CEUI), targeting ability to glucose-regulated protein 78 (GRP78)-overexpressing CRPC and anticancer effect of the SP94-DOX-NDs were assessed. The desired SP94-NDs were successfully prepared using the nanoemulsification method using a certain proportion of SP94-PEG-chitosan, perfluoropentane (PFP), Tween 20, and lecithin. SP94-NDs with a size of ∼300 nm showed great biocompatibility and CEUI ability. Compared with blank NDs, SP94-NDs exhibited higher tumor-specific targeting ability due to conjugation between the SP94 peptide and GRP78-overexpressing 22RV1 cells. Most importantly, in vitro and in vivo investigations showed that SP94-DOX-NDs combined with ultrasound could specifically deliver DOX into 22RV1 cells and thereby demonstrated a stronger anticancer effect than DOX-NDs and DOX. Thus, SP94-DOX-NDs may provide an efficient approach for the real-time imaging of tumors and triggered, accurate drug delivery to tumors.

Stiffness Could be a Predictor of AJCC Prognostic Stage Groups in Preoperative Invasive Ductal Carcinoma.

OBJECTIVES: This study aimed to evaluate the stiffness of 2-dimensional (2D) shear wave elastography (SWE) in preoperatively predicting the prognostic stage groups of invasive ductal carcinoma (IDC). METHODS: Eighty-six newly diagnosed lesions on 83 patients with IDCs were analyzed. All parameters from conventional ultrasound and stiffness to virtual touch tissue imaging and quantification were collected, and mean shear wave velocity (SWVmean) was calculated. Data on maximum diameter, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), histologic grading system and Tumor Node Metastasis (TNM) stages were collected. The levels of maximum shear wave velocity (SWVmax), minimum shear wave velocity (SWVmin) and SWVmean were compared. In receiver operating characteristic (ROC) curves analysis, the diagnostic efficacy was found in area under the curve (AUC). Parallel mode was used to improve the predictive value of sensitivity. RESULTS: The median stiffness of SWVmax and SWVmean for IDCs were 9.38 and 6.32 m/s for late stage (stages II, III, IV) and 6.39 m/s and 4.72 m/s for early stage (stage I) of the prognostic stage groups, respectively. The median stiffness values in the late stage were significantly higher than those in the early stage (P = .003, P = .005). The optimal cutoff stiffness of SWVmax and SWVmean were 8.62 and 6.13 m/s, respectively. In ROC curves analysis, the AUC for SWVmax was 0.742, and it showed a better diagnostic value than SWVmean (0.725). In predictive diagnosis, the sensitivity for SWVmax and SWVmean were both 62.50%. The parallel mode improved the prediction power of sensitivity to 68.75%. CONCLUSIONS: Preoperative SWV level may serve as a promising prognostic imaging indicator for breast IDCs.

Echogenic, Ultrasound-Sensitive Chitosan Nanodroplets for Spatiotemporally Controlled DKK-2 Gene Delivery to Prostate Cancer Cells.

PURPOSE: To synthesize echogenic chitosan/perfluorohexane nanodroplets (CNDs) for DKK-2 gene delivering in a spatiotemporally controlled manner in vitro. METHODS: The characteristics, contrast-enhanced ultrasound imaging, DNA binding and DNase protection capacity, DKK-2 gene transfection and effects on LNCaP cells of these CNDs were investigated. RESULTS: The obtained CNDs showed positive surface charges and could attract the genetic cargo with negative surface charges to form nanocomplexes. Agarose gel electrophoresis confirmed binding of the CNDs and pDNA. DKK-2 pDNA-loaded CNDs, in combination with ultrasound, ruptured and released DKK-2 pDNA, entering LNCaP cells through nano-scale pores in the cell membrane, which further reduced the proliferation of LNCaP cells. CONCLUSION: These stable and safe CNDs may be a promising choice to achieve efficient ultrasound-mediated gene delivery to specific tissues in a spatiotemporally controlled manner.

UTMD inhibit EMT of breast cancer through the ROS/miR-200c/ZEB1 axis.

As a potential drug/gene delivery system, the ultrasound-targeted microbubble destruction (UTMD) system can be used as a vehicle as well as increasing the permeability of biological barriers to enhance the effect of tumor treatment. However, the effect of UTMD in the tumor EMT process is unknown. In this study, we aimed to investigate the potential and mechanism of UTMD induced oxidative stress in inhibiting EMT of breast cancer. Human breast MDA231 cells were treated with microbubble (MB), ultrasound (US) and UTMD, respectively. The generation of oxidative stress, the levels of miR-200c, ZEB1 and vimentin, and the numbers of migratory cells were evaluated quantitatively and qualitatively by the measurement of intracellular reactive oxygen species (ROS), qRT-PCR, western blot assay, and transwell assay. Then, to evaluate the role of UTMD-induced oxidative stress and miR-200c in the epithelial-mesenchymal transition (EMT) inhibition, the ROS scavenger N-acetyl-L-cysteine (NAC) and miR-200c inhibitor were used before UTMD treatment. We found that UTMD induced oxidative stress, upregulated the expression of miR-200c, downregulated the expression of ZEB1 and vimentin and suppressed the MDA231 cell migration. The addition of NAC and miR-200c inhibitor had an opposite impact on the expression of miR-200c and ZEB1, thus hindered the effects of UTMD on MDA231 cells EMT. In conclusion, UTMD can inhibit the EMT characteristics of MDA231 cells. The mechanism may be related to the regulation of the miR-200c/ZEB1 axis through the generation of ROS induced by UTMD, which may provide a new strategy to prevent the tumor cells EMT under UTMD treatment.

Ultrasound Mediated Destruction of LMW-HA-Loaded and Folate-Conjugated Nanobubble for TAM Targeting and Reeducation.

PURPOSE: To synthesize and evaluate a novel folate-conjugated ultrasonic nanobubble (HA-FOL-NB) loading low-molecular-weight hyaluronic acid (LMW-HA) for specific tumor-associated macrophages (TAMs) targeting and reeducation. METHODS: The characteristics, cytotoxicity, contrast-enhanced ultrasound imaging (CEUS), and targeting ability to TAMs of HA-FOL-NBs were investigated. The TAMs reprogramming function of HA-FOL-NBs combining ultrasound targeted nanobubble destruction was assessed as well. RESULTS: HA-FOL-NBs (about 342 nm) showed remarkable contrast enhancement images, and higher targeting ability due to the folate to folate receptor interactions. Combined with ultrasound targeted nanobubble destruction, HA-FOL-NBs could specifically deliver LMW-HA into TAMs, thus exhibited stronger reeducation effect compared with free LMW-HA. CONCLUSION: These folate-conjugated and LMW-HA-loaded nanobubbles, with targeted CEUS imaging and TAMs reeducation, are expected to be a potential approach for tumor therapy based on TAMs, especially folate receptor-positive ones.

Ultrasound-responsive highly biocompatible nanodroplets loaded with doxorubicin for tumor imaging and treatment in vivo.

As an injectable anticancer drug delivery system, the biological safety of nanocarriers is the most important prerequisite for their clinical application. The objective of our study was to synthesize special ultrasound-responsive highly biocompatible chitosan nanodroplets (BCNDs), observe their spatiotemporally control the delivery of doxorubicin (DOX) in vivo. The experimental results showed that the BCNDs were successfully prepared with high biosafety in vivo and great ultrasound imaging ability. DOX-BCNDs promoted the anticancer effects of DOX in vivo and inhibited the development of tumors. They also reduced the side effects to the heart and kidneys. In conclusion, BCNDs are a new type of smart nanocarrier with high biocompatibility and efficacy have great potential to be used in the clinic.

pH- and Ultrasound-Responsive Paclitaxel-Loaded Carboxymethyl Chitosan Nanodroplets for Combined Imaging and Synergistic Chemoradiotherapy.

BACKGROUND: Synergistic chemoradiotherapy (CRT) has become a primary effective curative approach for many solid cancers. However, CRT is still associated with several obstacles, including the increases in side effects and systemic toxicity. Incorporating nanocarriers into CRT is a new and exciting approach to solve these obstacles. The purpose of the present study was to design a unique pH- and ultrasound-responsive perfluoropentane-encapsulated, paclitaxel (PTX)-loaded carboxymethyl chitosan nanodroplets (NDs) for combined imaging and synergistic CRT. MATERIALS AND METHODS: The NDs were prepared by a homogenization/emulsion method. Their physicochemical properties, echogenicity and biocompatibility were evaluated. PTX-loaded NDs with a high loading efficiency and encapsulation efficiency were prepared and their pH-responsive drug release profile was determined by dialysis sack method. Then, PC3 cells were exposed to (1) PTX (4 µg/mL), (2) NDs (30 µg/mL), (3) PTX-loaded NDs (34 µg/mL), (4) RT (6 Gy), (5) RT (10 Gy), (6) combination of PTX (4 µg/mL), ultrasound (0.5 W/cm2, 30 s) and RT (6 Gy), (7) combination of NDs (30 µg/mL), ultrasound (0.5 W/cm2, 30 s) and RT (6Gy), (8) combination of PTX-loaded NDs (30 µg/mL), ultrasound (0.5 W/cm2, 30 s) and RT (6 Gy). 24 hrs later, CCK-8 assay, flow cytometry and migration assay were carried out to evaluate their therapeutic effects in CRT. RESULTS: The desired NDs were successfully prepared, which were with round, spherical shapes, relatively smooth surfaces, core-shell structures and uniform in sizes (<300 nm with PDI<0.3 when at pH≧6.0). The NDs exhibited good abilities in pH-dependent charge conversion, biocompatibility and ultrasound contrast echogenicity. The in vitro drug release from PTX-loaded NDs (the highest loading efficiency and encapsulation efficiency were 20.35% and 91.58%) was pH dependent and exhibited an initial burst followed by a sustained drug release. The results of the CCK-8 assay, flow cytometry and migration assay all showed PTX-loaded NDs combined ultrasound and RT significantly enhanced cell responses in CRT. CONCLUSION: The pH- and ultrasound-responsive PTX-loaded NDs, which exhibited a high echogenicity, drug delivery ability and radiosensitization ability, could be a feasible option for combined imaging and novel enhancing approach in synergistic CRT.

New FH peptide-modified ultrasonic nanobubbles for delivery of doxorubicin to cancer-associated fibroblasts.

Aim: To synthesize and evaluate a novel FH peptide-modified ultrasonic nanobubble-loading doxorubicin (FH-NB-DOX) for specially cancer-associated fibroblasts (CAFs) targeting and eradication. Materials & methods: The characteristics, cytotoxicity, contrast-enhanced ultrasound imaging (CEUI), targeting ability and specially eradicating CAFs of these NBs were investigated. Results: FH-NB-DOX (about 208 nm) showed a good CEUI, and achieved higher targeting ability due to the conjunction ability of FH peptide to tenascin C protein high-level expressed in CAFs. Under ultrasound irradiation, FH-NB-DOX could delivery more DOX into CAFs, thus exhibited stronger eradication role compared with NB-DOX and free DOX. Conclusion: These new NBs, which combines the advantages of targeted theranostic agent and CEUI, is expected to be a potential approach for tumor therapy based on CAF targeting.

Abnormally expressed circular RNAs as novel non-invasive biomarkers for hepatocellular carcinoma: A meta-analysis.

BACKGROUND: Circular RNAs (circRNAs) are a newly discovered class of endogenous non-coding RNAs that may have roles in cancer genesis and development. In the recent literature, dysregulated circRNAs have been extensively investigated in hepatocellular carcinoma (HCC). Whether or not circRNAs are of clinical value for the management of HCC has not been characterized. AIM: To meta-analyze the diagnostic and prognostic value of abnormally expressed circRNAs in HCC. METHODS: Eligible studies were sourced from PubMed, EMBASE, and CNKI online databases. Data on patients' clinical characteristics, including diagnostic efficacy and overall survival, were extracted. The diagnostic and prognostic parameters were respectively synthesized using the bivariate meta-analysis model and multivariate Cox hazard regression analysis based on Stata 12.0. The trim and fill method was adopted to assess the possible effects from publication bias. RESULTS: A total of 21 eligible studies were included. The pooled sensitivity, specificity, and area under the curve of abnormally expressed circRNAs in distinguishing HCC from non-cancer controls were 0.78 (95%CI: 0.69-0.85), 0.80 (95%CI: 0.74-0.86), and 0.86, respectively. Survival analyses showed that the down-regulated circRNA expression signature correlated perfectly with HCC survival [hazard ratio (HR) = 0.42, 95%CI: 0.19-0.91, P = 0.028; I 2 = 92.7%, P = 0.000], whereas the HCC cases with high circRNA levels had significantly poorer prognoses than those of patients with low circRNA levels (HR = 2.22, 95%CI: 1.50-3.30, P = 0.000; I 2 = 91%, P = 0.000). Moreover, abnormally expressed circRNAs were intimately associated with tumor size, differentiation grade, microvascular invasion, metastasis, TNM stage, and serum alpha fetal protein level in patients with HCC. Stratified analysis based on sample type, control source, and expression status also yielded robust results. CONCLUSION: Abnormally expressed circRNA signatures show immense potential as novel non-invasive biomarker(s) for HCC diagnosis and prognosis.

Charge-conversion and ultrasound-responsive O-carboxymethyl chitosan nanodroplets for controlled drug delivery.

Aim: O-carboxymethyl chitosan/perfluorohexane nanodroplets (O-CS NDs) and doxorubicin-loading O-carboxymethyl chitosan nanodroplets were synthesized and functionally tested as drug delivery system in vitro. Materials & methods: The characteristics, charge conversion, stability, cytotoxicity, ultrasound imaging ability, interaction with tumor cells of the nanodroplets and eradication on tumor cells of the doxorubicin-loaded nanodroplets were investigated. Results: O-CS NDs (below 200 nm) achieved higher tumor cellular associations at acidic pH, with great serum stability, pH-dependent charge conversion and good ultrasound imaging ability. Doxorubicin-loading O-carboxymethyl chitosan nanodroplets exhibited strong cytotoxicity on PC-3 cells with ultrasound exposure. Conclusion: These stable, safe and smart O-CS NDs may be a promising approach to improve cell interaction efficiency as an ultrasound imaging and cancer-targeting drug delivery system.

Development of novel ST68/PLA-PEG stabilized ultrasound nanobubbles for potential tumor imaging and theranostic.

Nanobubbles (NBs) have received wide attention as theranostic agents and been extensively explored in various applications, especially in cancer. The aim of this study was to develop a novel kind of NBs which possess high echogenicity and good stability. This novel ultrasonic nanobubbles (ST68/PLA-PEG NBs) consist of perfluoropropane gas stabilized by Span 60 and Tween 80 (ST68) surfactant and synthesized PLA-PEG-NH2 block copolymers, and were prepared through the methods of mechanical shaking and low-speed centrifugation. A series of experiments were carried out to evaluate the physicochemical properties, echogenicity and cytotoxicity of this novel NBs. According to the amount ratio of copolymers to surfactant, the NBs were divided into 5 groups (0%, 5%, 10%, 15% and 20%). Group "10%" were the optimum NBs, with a size of 675.6 nm, polydispersity index of 0.39. Moreover, these NBs gave a maximum contrast intensity of 31.0 ±â€¯0.2 dB over baseline and little loss of contrast signal after 10 min. In conclusion, this novel kind of ST68/PLA-PEG NBs which exhibited a high echogenicity and good stability were successfully prepared, and they may offer a potential strategy for drug delivery and tumor-targeted theranostic.

Breast Cancer Cell Line Phenotype Affects Sonoporation Efficiency Under Optimal Ultrasound Microbubble Conditions.

BACKGROUND Ultrasound/microbubble (USMB)-mediated sonoporation is a new strategy with minimal procedural invasiveness for targeted and site-specific drug delivery to tumors. The purpose of this study was to explore the effect of different breast cancer cell lines on sonoporation efficiency, and then to identify an optimal combination of USMB parameters to maximize the sonoporation efficiency for each tumor cell line. MATERIAL AND METHODS Three drug-sensitive breast cell lines - MCF-7, MDA-MB-231, and MDA-MB-468 - and 1 multidrug resistance (MDR) cell line - MCF-7/ADR - were chosen. An orthogonal array experimental design approach based on 3 levels of 3 parameters (A: microbubble concentration, 10%, 20%, and 30%, B: sound intensity, 0.5, 1.0, and 1.5 W/cm², C: irradiation time, 30, 60, and 90 s) was employed to optimize the sonoporation efficiency. RESULTS The optimal USMB parameter combinations for different cell lines were diverse. Under optimal parameter combinations, the maximum sonoporation efficiency differences between different breast tumor cell lines were statistically significant (MDA-MB-231: 46.70±5.79%, MDA-MB-468: 53.44±5.69%, MCF-7: 59.88±5.53%, MCF-7/ADR: 65.39±4.01%, P<0.05), so were between drug-sensitive cell line and MDR cell line (MCF-7: 59.88±5.53%, MCF-7/ADR: 65.39±4.01%, p=0.026). CONCLUSIONS Different breast tumor cell lines have their own optimal sonoporation. Drug-resistant MCF-7/ADR cells had higher sonoporation efficiency than drug-sensitive MCF-7 cells. The molecular subtype of tumors should be considered when sonoporation is applied, and optimal parameter combination may have the potential to improve drug-delivery efficiency by increasing the sonoporation efficiency.