Value of Multimodal Data From Clinical and Sonographic Parameters in Predicting Recurrence of Hepatocellular Carcinoma After Curative Treatment.

OBJECTIVE: The objective of the work described here was to assess the value of the combination of pre-operative multimodal data-including clinical data, contrast-enhanced ultrasound (CEUS) information and liver stiffness measurement (LSM) based on 2-D shear wave elastography (SWE)-in predicting early (within 1 y) and late (after 1 y) recurrence of hepatocellular carcinoma (HCC) after curative treatment. METHODS: We retrospectively included 101 patients with HCC who met the Milan criteria and received curative treatment. The multimodel data from clinical parameters, LSM by 2-D SWE and CEUS enhancement patterns were collected. The association between different variables in HCC recurrence was accessed using a Cox proportional hazard model. On the basis of the independent factors of early recurrence, models with different source variables were established (Clinical Model, CEUS-Clinical Model, SWE-Clinical Model, CEUS-SWE-Clinical Model). The goodness-of-fit of models was evaluated and the performance trends of different models were calculated by time-dependent area under the curve (AUC). RESULTS: Two-dimensional SWE, CEUS enhancement patterns and clinical parameters (spleen length, multiple tumors, α-fetoprotein, albumin and prothrombin time) were independently associated with early recurrence (all p values <0.05). Multiple tumors and a decrease in albumin independently contributed to the late recurrence. The model fit of CEUS-SWE-Clinical Model was superior to other models in predicting early recurrence (all p values <0.05). The AUCs of the CEUS-Clinical Model were higher from 2 mo to 7 mo, while the SWE-Clinical Model had higher AUCs from 9 mo to 12 mo. CONCLUSION: CEUS enhancement patterns and 2-D SWE were independent predictors of HCC early recurrence as the two factors contributed to the predictive performance at different times. The multimodal model, which included diverse data in predicting early HCC recurrence, had the best goodness-of-fit.

Integration of Artificial Intelligence Decision Aids to Reduce Workload and Enhance Efficiency in Thyroid Nodule Management.

Importance: To optimize the integration of artificial intelligence (AI) decision aids and reduce workload in thyroid nodule management, it is critical to incorporate personalized AI into the decision-making processes of radiologists with varying levels of expertise. Objective: To develop an optimized integration of AI decision aids for reducing radiologists' workload while maintaining diagnostic performance compared with traditional AI-assisted strategy. Design, Setting, and Participants: In this diagnostic study, a retrospective set of 1754 ultrasonographic images of 1048 patients with 1754 thyroid nodules from July 1, 2018, to July 31, 2019, was used to build an optimized strategy based on how 16 junior and senior radiologists incorporated AI-assisted diagnosis results with different image features. In the prospective set of this diagnostic study, 300 ultrasonographic images of 268 patients with 300 thyroid nodules from May 1 to December 31, 2021, were used to compare the optimized strategy with the traditional all-AI strategy in terms of diagnostic performance and workload reduction. Data analyses were completed in September 2022. Main Outcomes and Measures: The retrospective set of images was used to develop an optimized integration of AI decision aids for junior and senior radiologists based on the selection of AI-assisted significant or nonsignificant features. In the prospective set of images, the diagnostic performance, time-based cost, and assisted diagnosis were compared between the optimized strategy and the traditional all-AI strategy. Results: The retrospective set included 1754 ultrasonographic images from 1048 patients (mean [SD] age, 42.1 [13.2] years; 749 women [71.5%]) with 1754 thyroid nodules (mean [SD] size, 16.4 [10.6] mm); 748 nodules (42.6%) were benign, and 1006 (57.4%) were malignant. The prospective set included 300 ultrasonographic images from 268 patients (mean [SD] age, 41.7 [14.1] years; 194 women [72.4%]) with 300 thyroid nodules (mean [SD] size, 17.2 [6.8] mm); 125 nodules (41.7%) were benign, and 175 (58.3%) were malignant. For junior radiologists, the ultrasonographic features that were not improved by AI assistance included cystic or almost completely cystic nodules, anechoic nodules, spongiform nodules, and nodules smaller than 5 mm, whereas for senior radiologists the features that were not improved by AI assistance were cystic or almost completely cystic nodules, anechoic nodules, spongiform nodules, very hypoechoic nodules, nodules taller than wide, lobulated or irregular nodules, and extrathyroidal extension. Compared with the traditional all-AI strategy, the optimized strategy was associated with increased mean task completion times for junior radiologists (reader 11, from 15.2 seconds [95% CI, 13.2-17.2 seconds] to 19.4 seconds [95% CI, 15.6-23.3 seconds]; reader 12, from 12.7 seconds [95% CI, 11.4-13.9 seconds] to 15.6 seconds [95% CI, 13.6-17.7 seconds]), but shorter times for senior radiologists (reader 14, from 19.4 seconds [95% CI, 18.1-20.7 seconds] to 16.8 seconds [95% CI, 15.3-18.3 seconds]; reader 16, from 12.5 seconds [95% CI, 12.1-12.9 seconds] to 10.0 seconds [95% CI, 9.5-10.5 seconds]). There was no significant difference in sensitivity (range, 91%-100%) or specificity (range, 94%-98%) between the 2 strategies for readers 11 to 16. Conclusions and Relevance: This diagnostic study suggests that an optimized AI strategy in thyroid nodule management may reduce diagnostic time-based costs without sacrificing diagnostic accuracy for senior radiologists, while the traditional all-AI strategy may still be more beneficial for junior radiologists.

Perfluorocarbon nanodrug induced oxygen self-enriching sonodynamic therapy improves cancer immunotherapy after insufficient radiofrequency ablation.

Residual lesions and undetectable metastasis after insufficient radiofrequency ablation (iRFA) are associated with earlier new metastases and poor survival in cancer patients, for induced aggressive tumor phenotype and immunosuppression. Programmed cell death protein 1(PD-1) blockade has been reported to enhance the radiofrequency ablation-elicited antitumor immunity, but its ability to eliminate incompletely ablated residual lesions has been questioned. Here, we report a combined treatment modality post iRFA based on integrating an oxygen self-enriching nanodrug PFH-Ce6 liposome@O2 nanodroplets (PCL@O2)-augmented noninvasive sonodynamic therapy (SDT) with PD-1 blockade. PCL@O2 containing Ce6 as the sonosensitizer and PFH as O2 reservoir, was synthesized as an augmented SDT nanoplatform and showed increased ROS generation to raise effective apoptosis of tumor cells, which also exposed more calreticulin to induce stronger immunogenic cell death (ICD). Combining with PD-1 blockade post iRFA, this optimized SDT induced a better anti-tumor response in MC38 tumor bearing mouse model, which not only arrested residual primary tumor progression, but also inhibited the growth of distant tumor, therefore prolonging the survival. Profiling of immune populations within the tumor draining lymph nodes and tumors further revealed that combination therapy effectively induced ICD, and promoted the maturation of dendritic cells, tumor infiltration of T cells, as well as activation of cytotoxic T lymphocytes. While iRFA alone could result in an increase of regulatory T cells (Tregs) in the residual tumors, SDT plus PD-1 blockade post iRFA reduced the number of Tregs in both primary and distant tumors. Moreover, the combined treatment could significantly initiate long-term immune memory, manifesting as elevated levels of CD8+ and CD4+ central memory cells. Therefore, this study establishes the preclinical proof of concept to apply oxygen self-enriching SDT to augment cancer immunotherapy after iRFA.

Artificial nano-red blood cells nanoplatform with lysosomal escape capability for ultrasound imaging-guided on-demand pain management.

Postoperative pain management would benefit significantly from an anesthetic that could take effect in an on-demand manner. An ultrasound would be an appropriate tool for such nanoplatform because it is widely used in clinical settings for ultrasound-guided anesthesia. Herein, we report a nanoplatform for postoperative on-demand pain management that can effectively enhance their analgesic time while providing ultrasonic imaging. Levobupivacaine and perfluoropentane were put into dendritic mesoporous silica and covered with red blood cell membranes to make the pain relief last longer in living organisms. The generated nanoplatform with gas-producing capability is ultrasonic responsive and can finely escape from the lysosomal in cells under ultrasound irradiation, maximizing the anesthetic effect with minimal toxicity. Using an incision pain model in vivo, levobupivacaine's sustained and controlled release gives pain reduction for approximately 3 days straight. The duration of pain relief is over 20 times greater than with a single injection of free levobupivacaine. Effective pain management was reached in vivo, and the pain reduction was enhanced by repeated ultrasonic irradiation. There was no detectable systemic or tissue injury under either of the treatments. Thus, our results suggest that nanoplatform with lysosomal escape capability can provide a practical ultrasound imaging-guided on-demand pain management strategy. STATEMENT OF SIGNIFICANCE: On-demand pain management is essential to postoperative patients. However, the traditional on-demand pain management strategy is hampered by the limited tissue penetration depth of near-infrared stimuli and the lack of proper imaging guidance. The proposed research is significant because it provides a nanoplatform for deep penetrated ultrasound controlled pain management under clinical applicable ultrasound imaging guidance. Moreover, the nanoplatform with prolonged retention time and lysosomal escape capability can provide long-term pain alleviation. Therefore, our results suggest that nanoplatform with lysosomal escape capability can provide an effective strategy for ultrasound imaging-guided on-demand pain management.

Nanodroplet-enhanced sonodynamic therapy potentiates immune checkpoint blockade for systemic suppression of triple-negative breast cancer.

Immune checkpoint blockade (ICB) has shown great promise in treating various advanced malignancies including triple-negative breast cancer (TNBC). However, only limited number of patients could benefit from it due to the low immune response rate caused by insufficient matured dendritic cells (DCs) and inadequate tumor infiltration of cytotoxic T lymphocytes (CTLs). Here, we report a combination therapeutic strategy which integrates STING pathway activation, hypoxia relief and sonodynamic therapy (SDT) with anti-PD-L1 therapy to improve the therapeutic outcome. The synthesized nanodroplet consisted of a O2-filled Perfluorohexane (PFH) core and a lipid membrane carrying sonosensitizer IR-780 and STING agonist Vadimezan (DMXAAs). It released O2 inside the hypoxic tumor tissue, thereby enhancing SDT which relied on O2 to generate cytotoxic reactive oxygen species (ROS). The co-delivered STING agonist DMXAAs promoted the maturation and tumor antigen cross-presenting of DCs for priming of CTLs. Moreover, SDT induced immunogenic cell death (ICD) of tumor to release abundant tumor-associated antigens, which increased tumor immunogenicity to promote tumor infiltration of CTLs. Consequently, not only a robust adaptive immune response was elicited but also the immunologically "cold" TNBC was turned "hot" to enable a potent anti-PD-L1 therapy. The nanodroplet demonstrated strong efficacy to systemically suppress TNBC growth and mimic distant tumor in vivo. STATEMENT OF SIGNIFICANCE: Only a limited number of triple-negative breast cancer (TNBC) patients can benefit from immune checkpoint blockade therapy due to its low immune response rate caused by insufficient matured DCs and inadequate tumor infiltration of cytotoxic T lymphocytes (CTLs). Interestingly, compelling evidence has shown that sonodynamic therapy (SDT) not only directly kills cancer cells but also elicits immunogenic cell death (ICD), which promotes tumor infiltration of cytotoxic T lymphocytes to transform an immunosuppressive "cold" tumor into a "hot" one. However, the hypoxic tumor microenvironment severely restricts the therapeutic efficiency of SDT, wherein, oxygen is indispensable in the process of ROS generation. Here, we report an O2-filled nanodroplet-enhanced sonodynamic therapy that significantly potentiated immune checkpoint blockade for systemic suppression of TNBC.

Intensity-adjustable pain management with prolonged duration based on phase-transitional nanoparticles-assisted ultrasound imaging-guided nerve blockade.

BACKGROUND: The lack of a satisfactory strategy for postoperative pain management significantly impairs the quality of life for many patients. However, existing nanoplatforms cannot provide a longer duration of nerve blockage with intensity-adjustable characteristics under imaging guidance for clinical applications. RESULTS: To overcome this challenge, we proposed a biocompatible nanoplatform that enables high-definition ultrasound imaging-guided, intensity-adjustable, and long-lasting analgesia in a postoperative pain management model in awake mice. The nanoplatform was constructed by incorporating perfluoropentane and levobupivacaine with red blood cell membranes decorated liposomes. The fabricated nanoplatform can achieve gas-producing and can finely escape from immune surveillance in vivo to maximize the anesthetic effect. The analgesia effect was assessed from both motor reactions and pain-related histological markers. The findings demonstrated that the duration of intensity-adjustable analgesia in our platform is more than 20 times longer than free levobupivacaine injection with pain relief for around 3 days straight. Moreover, the pain relief was strengthened by repeatable ultrasound irradiation to effectively manage postoperative pain in an intensity-adjustable manner. No apparent systemic and local tissue injury was detected under different treatments. CONCLUSION: Our results suggest that nanoplatform can provide an effective strategy for ultrasound imaging-guided intensity-adjustable pain management with prolonged analgesia duration and show considerable transformation prospects.

Analysis of Infectious Complications after Thermal Ablation of Hepatocellular Carcinoma and the Impact on Long-Term Survival.

PURPOSE: This study aims to complete a detailed record of the clinical characteristics and treatment of HCC patients with post-ablation infection and evaluate the infections on recurrence-free survival (RFS) and overall survival (OS) among patients receiving ultrasound-guided thermal ablation. METHODS: 3117 patients with liver tumors receiving thermal ablation from January 2010 to December 2021 were analyzed. A total of 49 patients with infectious complications after thermal ablation were selected as the infection group. A total of 49 patients without postoperative infection were randomly selected among those who underwent ablation within three days before or after the treatment date of the infection group as the control group. The clinical characteristics of both groups were analyzed by an independent sample t-test and chi-square test. A log-rank test was performed to compare the RFS and OS data. A multivariate Cox regression model was employed to identify prognostic factors influencing RFS and OS. Subgroup analyses of mild and severe infections were conducted to explore the infection-related situation further. RESULTS: Between mild and severe infection groups, there were statistically significant differences in the infection position (p = 0.043), positive rate of body fluid culture (p = 0.002), proportion of catheter drainage (p = 0.017), use of advanced antibiotics (p = 0.006), and outcome (p = 0.00). The Kaplan-Meier survival analysis revealed that postoperative infection was significantly correlated with tumor recurrence (p = 0.028), and severe infection was significantly associated with overall survival (p = 0.049). The cox model showed that postoperative infection was an independent variable for RFS deterioration (HR = 1.724, 95% CI: 1.038-2.862, p = 0.035). CONCLUSIONS: Postoperative infection among patients receiving ultrasound-guided thermal ablation adversely affected tumor progression. In addition, empirical antibiotics and catheterization to reduce pressure inside the lesion should be utilized to minimize symptoms in patients with postoperative infection.

Differentiation between combined hepatocellular carcinoma and hepatocellular carcinoma: comparison of diagnostic performance between ultrasomics-based model and CEUS LI-RADS v2017.

BACKGROUND: The imaging findings of combined hepatocellular cholangiocarcinoma (CHC) may be similar to those of hepatocellular carcinoma (HCC). CEUS LI-RADS may not perform well in distinguishing CHC from HCC. Studies have shown that radiomics has an excellent imaging analysis ability. This study aimed to establish and confirm an ultrasomics model for differentiating CHC from HCC. METHODS: Between 2004 and 2016, we retrospectively identified 53 eligible CHC patients and randomly included 106 eligible HCC patients with a ratio of HCC:CHC = 2:1, all of whom were categorized according to Contrast-Enhanced (CE) ultrasonography (US) Liver Imaging Reporting and Data System (LI-RADS) version 2017. The model based on ultrasomics features of CE US was developed in 74 HCC and 37 CHC and confirmed in 32 HCC and 16 CHC. The diagnostic performance of the LI-RADS or ultrasomics model was assessed by the area under the curve (AUC), accuracy, sensitivity and specificity. RESULTS: In the entire and validation cohorts, 67.0% and 81.3% of HCC cases were correctly assigned to LR-5 or LR-TIV contiguous with LR-5, and 73.6% and 87.5% of CHC cases were assigned to LR-M correctly. Up to 33.0% of HCC and 26.4% of CHC were misclassified by CE US LI-RADS. A total of 90.6% of HCC as well as 87.5% of CHC correctly diagnosed by the ultrasomics model in the validation cohort. The AUC, accuracy, sensitivity of the ultrasomics model were higher though without significant difference than those of CE US LI-RADS in the validation cohort. CONCLUSION: The proposed ultrasomics model showed higher ability though the difference was not significantly different for differentiating CHC from HCC, which may be helpful in clinical diagnosis.

A hydrogen peroxide economizer for on-demand oxygen production-assisted robust sonodynamic immunotherapy.

The outcome of sonodynamic immunotherapy is significantly limited by tumor hypoxia. To overcome this obstacle, one common solution is to catalyze the conversion of endogenous H2O2 into O2. However, the effectiveness of this strategy is limited by the insufficient concentration of H2O2 in the tumor microenvironment (TME). Herein, we developed a H2O2 economizer for on-demand O2 supply and sonosensitizer-mediated reactive oxygen species production during ultrasound activation, thereby alleviating hypoxia-associated limitations and augmenting the efficacy of sonodynamic immunotherapy. Methods: The H2O2 economizer is constructed by electrostatic adsorption and π-π interactions between the Fe-doped polydiaminopyridine (Fe-PDAP) nanozyme and chlorin e6. By employing a biomimetic engineering strategy with cancer cell membranes, we addressed the premature leakage issue and increased tumor-site accumulation of nanoparticles (membrane-coated Fe-PDAP/Ce6, MFC). Results: The prepared MFC could significantly attenuate the catalytic activity of Fe-PDAP by reducing their contact with H2O2. Ultrasound irradiation promoted MFC dissociation and the exposure of Fe-PDAP for a more robust O2 supply. Moreover, the combination of MFC-enhanced sonodynamic therapy with anti-programmed cell death protein-1 antibody (aPD-1) immune checkpoint blockade induced a strong antitumor response against both primary tumors and distant tumors. Conclusion: This as-prepared H2O2 economizer significantly alleviates tumor hypoxia via reducing H2O2 expenditure and that on-demand oxygen-elevated sonodynamic immunotherapy can effectively combat tumors.

Contrast-Enhanced Ultrasound for Differentiation Between Poorly Differentiated Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma.

PURPOSE: To evaluate the diagnostic performance of LR-5 for diagnosing poorly differentiated hepatocellular carcinoma (p-HCC). To build a contrast-enhanced ultrasound (CEUS) signature for improving the differential diagnostic performance between p-HCC and intrahepatic cholangiocarcinoma (ICC). METHODS: The B-mode ultrasound (BUS) and CEUS features of 60 p-HCCs and 56 ICCs were retrospectively analyzed. The CEUS LI-RADS category was assigned according to CEUS LI-RADS v2017. A diagnostic CEUS signature was built based on the independent significant features. An ultrasound (US) signature combining both BUS and CEUS features was also built. The diagnostic performances of the CEUS signature, US signature, and LR-5 were evaluated by receiver operating characteristic (ROC) analysis. RESULTS: One (1.7%) p-HCC and 26 (46.4%) ICC patients presented cholangiectasis or cholangiolithiasis (P < .001). Fifty-four (90.0%) p-HCCs and 8 (14.3%) ICCs showed clear boundaries in the artery phase (P < .001). The washout times of p-HCCs and ICCs were 81.0 ± 42.5 s and 34.7 ± 8.6 s, respectively (P < .001). The AUC, sensitivity, and specificity of the CEUS signature, US signature, and LR-5 were 0.955, 91.67%, and 90.57% versus 0.976, 96.67%, and 92.45% versus 0.758, 51.67%, and 100%, respectively. The AUC and sensitivity of CEUS LI-RADS were much lower than those of the CEUS and US signatures (P < .001). CONCLUSION: LR-5 had high specificity but low sensitivity in diagnosing p-HCC. When the washout time and tumor boundary were included in the CEUS signature, the sensitivity and AUC were remarkably increased in the differentiation between p-HCC and ICC.

Contrast-Enhanced Ultrasound-Based Nomogram: A Potential Predictor of Individually Postoperative Early Recurrence for Patients With Combined Hepatocellular-Cholangiocarcinoma.

PURPOSES: To evaluate the postsurgical prognostic implication of contrast-enhanced ultrasound (CEUS) for combined hepatocellular-cholangiocarcinoma (CHC). To build a CEUS-based early recurrence prediction classifier for CHC, in comparison with tumor-node-metastasis (TNM) staging. METHODS: The CEUS features and clinicopathological findings of each case were analyzed, and the Liver Imaging Reporting and Data System categories were assigned. The recurrence-free survival associated factors were evaluated by Cox proportional hazard model. Incorporating the independent factors, nomograms were built to estimate the possibilities of 3-month, 6-month, and 1-year recurrence and whose prognostic value was determined by time-dependent receiver operating characteristics, calibration curves, and hazard layering efficiency validation, comparing with TNM staging system. RESULTS: In the multivariable analysis, the levels of carbohydrate antigen 19-9, prothrombin time and total bilirubin, and tumor shape, the Liver Imaging Reporting and Data System category were independent factors for recurrence-free survival. The LR-M category showed longer recurrence-free survival than did the LR-4/5 category. The 3-month, 6-month, and 1-year area under the curves of the CEUS-clinical nomogram, clinical nomogram, and TNM staging system were 0.518, 0.552, and 0.843 versus 0.354, 0.240, and 0.624 (P = .048, .049, and .471) vs. 0.562, 0.545, and 0.843 (P = .630, .564, and .007), respectively. The calibration curves of the CEUS-clinical model at different prediction time pionts were all close to the ideal line. The CEUS-clinical model effectively stratified patients into groups of high and low risk of recurrence in both training and validation set, while the TNM staging system only works on the training set. CONCLUSIONS: Our CEUS-clinical nomogram is a reliable early recurrence prediction tool for hepatocellular-cholangiocarcinoma and helps postoperative risk stratification.

Can monodisperse microbubble-based three-dimensional contrast-enhanced ultrasound reduce quantitative heterogeneity? An in vitro study.

BACKGROUND: Heterogeneity within the tumor may cause large heterogeneity in quantitative perfusion parameters. Three-dimensional contrast-enhanced ultrasound (3D-CEUS) can show the spatial relationship of vascular structure after post-acquisition reconstruction and monodisperse bubbles can resonate the ultrasound pulse, resulting in the increase in sensitivity of CEUS imaging. OBJECTIVES: To evaluate whether the combination of 3D-CEUS and monodisperse microbubbles could reduce the heterogeneity of quantitative CEUS. MATERIAL AND METHODS: Three in vitro perfusion models with perfusion volume ratio of 1:2:4 were set up. Both quantitative 2D-CEUS and 3D-CEUS were used to acquire peak intensity (PI) with 2 kinds of ultrasound agents. One was a new kind of monodisperse bubbles produced in this study, named Octafluoropropane-loaded cerasomal microbubbles (OC-MBs), the other was SonoVue®. The coefficient of variation (CV) was calculated to evaluate the cross-sectional variability. Pearson's correlation analysis was used to assess the correlation between weighted PIs (average of PIs of 3 different planes) and perfusion ratios. RESULTS: The average CVs of quantitative 3D-CEUS was slightly lower than that of 2D-CEUS (0.41 ±0.17 compared to 0.55 ±0.26, p = 0.3592). As for quantitative 3D-CEUS, the PI of the OC-MBs has shown better stability than that of SonoVue®, but without a significant difference (average CVs: 0.32 ±0.19 compared to 0.50 ±0.10, p = 0.0711). In the 2D-CEUS condition, the average CVs of OC-MBs group and SonoVue® group were 0.68 ±0.15 and 0.41 ±0.17 (p = 0.2747). As for 3D-CEUS condition, using OC-MBs group and SonoVue®, the r-values of the weighted PI and perfusion ratio were 0.8685 and 0.5643, respectively, while that of 2D-CEUS condition were 0.7760 and 0.3513, respectively. CONCLUSIONS: Our in vitro experiments showed that OC-MBs have the potential in acquiring more stable quantitative CEUS value, as compared to the SonoVue® in 3D-CEUS condition. The combination of 3D-CEUS and OC-MBs can reflect perfusion volume more precisely and may be a potential way to reduce quantitative heterogeneity.

One-Pot Approach to Fe2+ /Fe3+ -Based MOFs with Enhanced Catalytic Activity for Fenton Reaction.

Smart theragnostic nanoplatforms exhibit great promise in clinical tumor treatment. The Fe-based Fenton reaction in tumor sites may generate reactive oxygen species to kill cancer cells with negligible side effects on normal tissues. However, its efficiency and duration are limited by the low intracellular concentration of H2 O2 , weak acidicity of tumor tissue, and low catalytic activity of conventional Fenton reagents. Herein, a facile strategy is proposed to efficiently overcome these obstacles. An efficient enzymatic/Fenton-starvation nanoreactor PMs loaded with glucose oxidase and perfluoropentane (PGPMs) is constructed through synthesizing methoxy-PEG-carboxymethy-modified iron (Fe2+ /Fe3+ )-based metal-organic frameworks (PMs), followed by loading glucose oxidase (GOx) and perfluoropentane (PFP). PGPMs accumulating in the tumor tissue exhibit tumor microenvironment-responsive biodegradable behavior and unusual catalytic activity for Fenton reaction advantageous over Fe3+ -based MOFs. Meanwhile, encapsulation of GOx into PGPMs further significantly increases the catalytic activity for Fenton reaction and also induces starvation therapy. PGPMs also exhibit considerable capabilities of ultrasound and tumor microenvironment-responsive T2 MR imaging applicable for contrast-enhanced diagnosis. Both in vitro and in vivo studies demonstrate the great diagnostic and therapeutic potentials of this nanoreactor in tumor.

Modulation of Tumor Hypoxia by pH-Responsive Liposomes to Inhibit Mitochondrial Respiration for Enhancing Sonodynamic Therapy.

BACKGROUND AND PURPOSE: Sonodynamic therapy (SDT) has been widely used for the noninvasive treatment of solid tumors, but the hypoxic tumor microenvironment limits its therapeutic effect. The current methods of reoxygenation to enhance SDT have limitations, prompting reconsideration of the design of therapeutic approaches. Here, we developed a tumor microenvironment-responsive nanoplatform by reducing oxygen consumption to overcome hypoxia-induced resistance to cancer therapy. METHODS: A pH-responsive drug-loaded liposome (MI-PEOz-lip) was prepared and used to reduce oxygen consumption, attenuating hypoxia-induced resistance to SDT and thereby improving therapeutic efficiency. Photoacoustic imaging (PAI) and fluorescence imaging (FI) of MI-PEOz-lip were evaluated in vitro and in breast xenograft tumor models. The pH-sensitive functionality of MI-PEOz-lip was applied for pH-triggered cargo release, and its capacity was evaluated. The MI-PEOz-lip-mediated SDT effect was compared with other treatments in vivo. RESULTS: MI-PEOz-lip was demonstrated to specifically accumulate in tumors. Metformin molecules in liposomes selectively accumulate in tumors by pH-responsive drug release to inhibit the mitochondrial respiratory chain while releasing IR780 to the tumor area. These pH-responsive liposomes demonstrated PAI and FI imaging capabilities in vitro and in vivo, providing potential for treatment guidance and monitoring. In particular, the prepared MI-PEOz-lip combined with ultrasound irradiation effectively inhibited breast tumors by producing toxic reactive singlet oxygen species (ROS), while the introduction of metformin inhibited mitochondrial respiration and reduced tumor oxygen consumption, resulting in excellent sonodynamic therapy performance compared with other treatments. CONCLUSION: In this study, we present a novel strategy to achieve high therapeutic efficacy of SDT by the rational design of multifunctional nanoplatforms. This work provides a new strategy that can solve the current problems of inefficient oxygen delivery strategies and weaken resistance to various oxygen-dependent therapies.

Redox Responsive Metal Organic Framework Nanoparticles Induces Ferroptosis for Cancer Therapy.

Ferroptosis is attracting significant attention due to its effectiveness in tumor treatment. The efficiency to produce toxic lipid peroxides (LPOs) at the tumor site plays a key role in ferroptosis. A hybrid PFP@Fe/Cu-SS metal organic framework (MOF) is synthesized and shown to increase intratumoral LPO content through redox reactions generating ·OH. In addition, glutathione (GSH) depletion through disulfide-thiol exchange leads to the inactivation of glutathione peroxide 4 (GPX4), which results in a further increase in LPO content. This MOF exhibits high inhibitory effect on the growth of xenografted Huh-7 tumors in mice. The coadministration of a ferroptosis inhibitor reduces the antitumor effect of the MOF, leading to a restoration of GPX4 activity and an increase in tumor growth. Moreover, the construction of Cu into mesoporous PFP@Fe/Cu-SS not only allows the MOF to be used as a contrast agent for T1 -weighted magnetic resonance imaging, but also renders its photothermal conversion capacity. Thus, near-infrared irradiation is able to induce photothermal therapy and transform the encapsulated liquid perfluoropentane into microbubbles for ultrasound imaging.

Ultrasomics for Early Evaluation of the Tumor Response to MicroRNA-122 in a Nude Mouse Hepatocellular Carcinoma Model.

OBJECTIVES: To explore the value of ultrasomics in temporal monitoring of tumor changes in response to gene therapy in hepatocellular carcinoma compared with methods according to the Response Evaluation Criteria in Solid Tumors (RECIST) and modified RECIST (mRECIST). METHODS: Hepatocellular carcinoma-bearing mice were injected intratumorally with microRNA-122 (miR-122) mimics and an miR-122 negative control in the treatment and control groups, respectively. The injections were performed every 3 days for 5 times (on days 0, 3, 6, 9, and 12). Before each injection and at the experiment ending, 2-dimensional ultrasound imaging was performed for tumor size measurement with RECIST and computing a quantitative imaging analysis with ultrasomics. To analyze the tumor perfusion by mRECIST, perfusion parameters were analyzed offline based on dynamic contrast-enhanced ultrasound image videos using SonoLiver software (TomTec, Unterschleissheim, Germany) on day 13. Tumor miR-122 expression was then analyzed by real-time reverse transcription-polymerase chain reaction experiments. RESULTS: Tumors in mice treated with miR-122 mimics demonstrated a mean ± SD 763- ± 60-fold increase in miR-122 levels compared with tumors in the control group. With RECIST, a significant therapeutic response evaluated by tumor size changes was detected after day 9 (days 9, 12, and 13; P < .001). With mRECIST, no parameters showed significant differences (P > .05). Significant different features of the 2-dimensional ultrasound images between the groups were detected by the ultrasomics analysis, and the model could be successfully built. The ultrasomics score values between the groups were statistically significant after day 6 (days 6, 9, 12, and 13; P < .05). CONCLUSIONS: Ultrasomics revealed significant changes after the second injection of miR-122, showing the potential as an important imaging biomarker for gene therapy.

Ultrasound-Assisted miR-122-Loaded Polymeric Nanodroplets for Hepatocellular Carcinoma Gene Therapy.

Ultrasound-induced microbubble sonoporation has been shown to effectively improve drug/gene delivery efficiency by enhancing tissue and cell permeability. However, the microscale size and short duration of ultrasound contrast agents limit their accumulation in target areas. Here, a kind of ultrasound-triggered phase-transitioning and size-changing cationic nanodroplet, perfluoropentane/C9F17-PAsp(DET)/miR-122/poly(glutamic acid)-g-MeO-poly(ethylene glycol) (PGA-g-mPEG) ternary nanodroplets (PFP-TNDs/miR-122), was developed to deliver microRNA-122 (miR-122) for hepatocellular carcinoma (HCC) treatment. PFP served as an ultrasound-sensitive core for ultrasound-triggered phase transition and size change from the nanoscale to the microscale. Positively charged C9F17-PAsp(DET) ensured adequate miRNA loading. PGA-g-mPEG, which served as the shell of the nanodroplet, modified the nanodroplets, enhanced their stability in serum, and protected miR-122 from degradation in vivo. The results exhibited that PFP-TNDs/miR-122 has a nanosize diameter (362 ± 15 nm) and remained stable for 24 h. After treatment with PFP-TNDs/miR-122 combined with ultrasound irradiation, the miR-122 expression level was significantly increased by approximately 600-fold in HepG2 cells, 500-fold in SMMC-7721 cells, and 30-fold in human HCC xenografts. Moreover, PFP-TNDs/miR-122 combined with ultrasound radiation effectively suppressed the growth, migration, and invasion of HCC cells, and inhibited tumor proliferation in mice. This study revealed that the biodegradable PFP-TNDs is a promising therapeutic gene carrier with functions of gene protection and effective gene delivery for clinical applications. Furthermore, PFP-TNDs/miR-122 associated with ultrasound irradiation may pave a new way to improve the prognosis of patients with HCC.

Comparison of Real-Time Two-Dimensional and Three-Dimensional Contrast-Enhanced Ultrasound to Quantify Flow in an In Vitro Model: A Feasibility Study.

BACKGROUND This feasibility study aimed to compare real-time two-dimensional contrast-enhanced ultrasound (2D-CEUS) and three-dimensional contrast-enhanced ultrasound (3D-CEUS) to quantify flow in an in vitro model. MATERIAL AND METHODS Five polyvinyl chloride (PVC) tubes were used for the perfusion models and used SonoVue ultrasound contrast agent with a perfusion volume ratio of 1: 2: 4: 8: 16. The contrast was injected at a constant speed to compare the raw quantitative data of 2D-CEUS and 3D-CEUS at angles of 0°, 45°, and 90°. The coefficient of variation (CV) of the peak intensity (PI) in the model were compared and the correlations between weighted PI and perfusion volume were analyzed. RESULTS In the three angles used, real-time 3D-CEUS resulted in a more comprehensive view of the spatial relationships in the perfusion model. Using real-time 2D-CEUS, the mean CV was 0.92±0.36, and the mean CV in the real-time 3D-CEUS model was significantly less at 0.48±0.32 (p<0.001). Quantitative 3D-CEUS parameters showed a good correlation with those of 2D-CEUS with an r-value of 0.93 (p=0.02). The r-value of weighted PI and the perfusion ratio using 2D-CEUS was 0.66 (p=0.23) compared with values in 3D-CEUS of 0.84 (p=0.08). CONCLUSIONS The combination of real-time 3D-CEUS and quantitative analysis identified the spatial distribution of the changes in angle in the model, which was less influenced by sectional planes, and was more representative of the perfusion volume when compared with 2D-CEUS. Quantitative real-time 3D-CEUS requires in vivo studies to evaluate the potential role in the clinical evaluation of vascular perfusion of malignant tumors.

Theranostic Nanomedicine Carrying L-Menthol and Near-Infrared Dye for Multimodal Imaging-Guided Photothermal Therapy of Cancer.

Photothermal therapy (PTT) as an emerging technique for cancer treatment has drawn great attention owing to its minimally invasive nature. However, it is difficult to achieve a complete tumor regression due to the heterogeneous heat distribution over the tumor. Application of photothermal conversion agents may enhance PTT efficiency, and a multifunctional imaging may provide guidance for the implementation of PTT. Herein, an L-menthol/IR-780 loaded liposome (MIL) is prepared to achieve NIR-triggered cavitation for enhancing photothermal ablation. The synthesized MIL possesses outstanding colloidal stability and photoacoustic/near infrared fluorescence/ultrasound (PA/NIRF/US) imaging contrast to offer multimodal imaging-guided photothermal therapy of cancer. Upon irradiation, the IR-780 acts as the photoabsorber to convert NIR light into heat energy. More importantly, the produced hyperthermia can not only induce ablation of tumor cells but also trigger vaporization and bubbling of encapsulated L-menthol (menthol). Consequently, the generated menthol bubbles obviously enhance the US imaging signal and promote photothermal ablation of the tumor.