Effect of Ambient Conditions on Acoustic Activation of the Perfluoropropane Droplets Within the Infarct Zone.

BACKGROUND: Acoustically activated perfluoropropane droplets (PD) formulated from lipid encapsulated microbubble preparations produce a delayed myocardial contrast enhancement that preferentially highlights the infarct zones (IZ). Since activation of PDs may be temperature sensitive, it is unclear what effect body temperature (BT) has on acoustic activation (AA). OBJECTIVE: We sought to determine whether the microvascular retention and degree of myocardial contrast intensity (MCI) would be affected by BT at the time of intravenous injection. METHODS: We administered intravenous (IV) PD in nine rats following 60 min of ischemia followed by reperfusion. Injections in these rats were given at temperatures above and below 36.5°C, with high MI activation in both groups at 3 or 6 min following IV injection (IVI). In six additional rats (three in each group), IV PDs were given only at one temperature (<36.5°C or ≥36.5°C), permitting a total of 12 comparisons of different BT. Differences in background subtracted MCI at 3-6 min post-injection were compared in the infarct zone (IZ) and remote zone (RZ). Post-mortem lung hematoxylin and eosin (H&E) staining was performed to assess the effect potential thermal activation on lung tissue. RESULTS: Selective MCI within the IZ was observed in 8 of 12 rats who received IVI of PDs at <36.5°C, but none of the 12 rats who had IVI at the higher temperature (p < 0.0001). Absolute MCI following droplet activation was significantly higher in both the IZ and RZ when given at the lower BT. H&E indicated significant red blood extravasation in 5/7 rats who had had IV injections at higher BT, and 0/7 rats who had IV PDs at <36.5°C. CONCLUSIONS: Selective IZ enhancement with AA of intravenous PDs is possible, but temperature sensitive. Thermal activation appears to occur when PDs are given at higher temperatures, preventing AA, and increasing unwanted bioeffects.

Melatonin suppresses atherosclerosis by ferroptosis inhibition via activating NRF2 pathway.

Melatonin (MLT), a conserved small indole compound, exhibits anti-inflammatory and antioxidant properties, contributing to its cardioprotective effects. Lipoprotein-associated phospholipase A2 (Lp-PLA2) is associated with atherosclerosis disease risk, and is known as an atherosclerosis risk biomarker. This study aimed to investigate the impact of MLT on Lp-PLA2 expression in the atherosclerotic process and explore the underlying mechanisms involved. In vivo, ApoE-/- mice were fed a high-fat diet, with or without MLT administration, after which the plaque area and collagen content were assessed. Macrophages were pretreated with MLT combined with ox-LDL, and the levels of ferroptosis-related proteins, NRF2 activation, mitochondrial function, and oxidative stress were measured. MLT administration significantly attenuated atherosclerotic plaque progression, as evidenced by decreased plaque area and increased collagen. Compared with those in the high-fat diet (HD) group, the levels of glutathione peroxidase 4 (GPX4) and SLC7A11 (xCT, a cystine/glutamate transporter) in atherosclerotic root macrophages were significantly increased in the MLT group. In vitro, MLT activated the nuclear factor-E2-related Factor 2 (NRF2)/SLC7A11/GPX4 signaling pathway, enhancing antioxidant capacity while reducing lipid peroxidation and suppressing Lp-PLA2 expression in macrophages. Moreover, MLT reversed ox-LDL-induced ferroptosis, through the use of ferrostatin-1 (a ferroptosis inhibitor) and/or erastin (a ferroptosis activator). Furthermore, the protective effects of MLT on Lp-PLA2 expression, antioxidant capacity, lipid peroxidation, and ferroptosis were decreased in ML385 (a specific NRF2 inhibitor)-treated macrophages and in AAV-sh-NRF2 treated ApoE-/- mice. MLT suppresses Lp-PLA2 expression and atherosclerosis processes by inhibiting macrophage ferroptosis and partially activating the NRF2 pathway.

Low-intensity pulsed ultrasound protects from inflammatory dilated cardiomyopathy through inciting extracellular vesicles.

AIMS: CD4+ T cells are activated during inflammatory dilated cardiomyopathy (iDCM) development to induce immunogenic responses that damage the myocardium. Low-intensity pulsed ultrasound (LIPUS), a novel physiotherapy for cardiovascular diseases, has recently been shown to modulate inflammatory responses. However, its efficacy in iDCM remains unknown. Here, we investigated whether LIPUS could improve the severity of iDCM by orchestrating immune responses and explored its therapeutic mechanisms. METHODS AND RESULTS: In iDCM mice, LIPUS treatment reduced cardiac remodelling and dysfunction. Additionally, CD4+ T cell inflammatory responses were suppressed. LIPUS increased Treg cells while decreasing Th17 cells. LIPUS mechanically stimulates endothelial cells, resulting in increased secretion of extracellular vesicles (EVs), which are taken up by CD4+ T cells and alter their differentiation and metabolic patterns. Moreover, EVs selectively loaded with microRNA (miR)-99a are responsible for the therapeutic effects of LIPUS. The hnRNPA2B1 translocation from the nucleus to the cytoplasm and binding to caveolin-1 and miR-99a confirmed the upstream mechanism of miR-99a transport. This complex is loaded into EVs and taken up by CD4+ T cells, which further suppress mTOR and TRIB2 expression to modulate cellular differentiation. CONCLUSION: Our findings revealed that LIPUS uses an EV-dependent molecular mechanism to protect against iDCM progression. Therefore, LIPUS is a promising new treatment option for iDCM.

Acoustic Activation Imaging With Intravenous Perfluoropropane Nanodroplets Results in Selective Bioactivation of the Risk Area.

BACKGROUND: Acoustically activatable perfluoropropane droplets (PD) can be formulated from commercially available microbubble preparations. Diagnostic transthoracic ultrasound frequencies have resulted in acoustic activation (AA) predominately within myocardial infarct zones (IZ). OBJECTIVE: We hypothesized that the AA area following acute coronary ischemia/reperfusion (I/R) would selectively enhance the developing scar zone, and target bioeffects specifically to this region. METHODS: We administered intravenous PD in 36 rats and 20 pigs at various stages of myocardial scar formation (30 minutes, 1 day, and 7 days post I/R) to determine what effect infarct age had on the AA within the IZ. This was correlated with histology, myeloperoxidase activity, and tissue nitrite activity. RESULTS: The degree of AA within the IZ in rats was not associated with collagen content, neutrophil infiltration, or infarct age. AA within 24 hours of I/R was associated with increased nitric oxide utilization selectively within the IZ (P < .05 compared with remote zone). The spatial extent of AA in pigs correlated with infarct size only when performed before sacrifice at 7 days (r = .74, P < .01). CONCLUSIONS: Acoustic activation of intravenous PD enhances the developing scar zone following I/R, and results in selective tissue nitric oxide utilization.

Ultrasound radiomics models based on multimodal imaging feature fusion of papillary thyroid carcinoma for predicting central lymph node metastasis.

Objective: This retrospective study aimed to establish ultrasound radiomics models to predict central lymph node metastasis (CLNM) based on preoperative multimodal ultrasound imaging features fusion of primary papillary thyroid carcinoma (PTC). Methods: In total, 498 cases of unifocal PTC were randomly divided into two sets which comprised 348 cases (training set) and 150 cases (validition set). In addition, the testing set contained 120 cases of PTC at different times. Post-operative histopathology was the gold standard for CLNM. The following steps were used to build models: the regions of interest were segmented in PTC ultrasound images, multimodal ultrasound image features were then extracted by the deep learning residual neural network with 50-layer network, followed by feature selection and fusion; subsequently, classification was performed using three classical classifiers-adaptive boosting (AB), linear discriminant analysis (LDA), and support vector machine (SVM). The performances of the unimodal models (Unimodal-AB, Unimodal-LDA, and Unimodal-SVM) and the multimodal models (Multimodal-AB, Multimodal-LDA, and Multimodal-SVM) were evaluated and compared. Results: The Multimodal-SVM model achieved the best predictive performance than the other models (P < 0.05). For the Multimodal-SVM model validation and testing sets, the areas under the receiver operating characteristic curves (AUCs) were 0.910 (95% CI, 0.894-0.926) and 0.851 (95% CI, 0.833-0.869), respectively. The AUCs of the Multimodal-SVM model were 0.920 (95% CI, 0.881-0.959) in the cN0 subgroup-1 cases and 0.828 (95% CI, 0.769-0.887) in the cN0 subgroup-2 cases. Conclusion: The ultrasound radiomics model only based on the PTC multimodal ultrasound image have high clinical value in predicting CLNM and can provide a reference for treatment decisions.

Deep learning for the diagnosis of suspicious thyroid nodules based on multimodal ultrasound images.

Objectives: This study aimed to differentially diagnose thyroid nodules (TNs) of Thyroid Imaging Reporting and Data System (TI-RADS) 3-5 categories using a deep learning (DL) model based on multimodal ultrasound (US) images and explore its auxiliary role for radiologists with varying degrees of experience. Methods: Preoperative multimodal US images of 1,138 TNs of TI-RADS 3-5 categories were randomly divided into a training set (n = 728), a validation set (n = 182), and a test set (n = 228) in a 4:1:1.25 ratio. Grayscale US (GSU), color Doppler flow imaging (CDFI), strain elastography (SE), and region of interest mask (Mask) images were acquired in both transverse and longitudinal sections, all of which were confirmed by pathology. In this study, fivefold cross-validation was used to evaluate the performance of the proposed DL model. The diagnostic performance of the mature DL model and radiologists in the test set was compared, and whether DL could assist radiologists in improving diagnostic performance was verified. Specificity, sensitivity, accuracy, positive predictive value, negative predictive value, and area under the receiver operating characteristics curves (AUC) were obtained. Results: The AUCs of DL in the differentiation of TNs were 0.858 based on (GSU + SE), 0.909 based on (GSU + CDFI), 0.906 based on (GSU + CDFI + SE), and 0.881 based (GSU + Mask), which were superior to that of 0.825-based single GSU (p = 0.014, p< 0.001, p< 0.001, and p = 0.002, respectively). The highest AUC of 0.928 was achieved by DL based on (G + C + E + M)US, the highest specificity of 89.5% was achieved by (G + C + E)US, and the highest accuracy of 86.2% and sensitivity of 86.9% were achieved by DL based on (G + C + M)US. With DL assistance, the AUC of junior radiologists increased from 0.720 to 0.796 (p< 0.001), which was slightly higher than that of senior radiologists without DL assistance (0.796 vs. 0.794, p > 0.05). Senior radiologists with DL assistance exhibited higher accuracy and comparable AUC than that of DL based on GSU (83.4% vs. 78.9%, p = 0.041; 0.822 vs. 0.825, p = 0.512). However, the AUC of DL based on multimodal US images was significantly higher than that based on visual diagnosis by radiologists (p< 0.05). Conclusion: The DL models based on multimodal US images showed exceptional performance in the differential diagnosis of suspicious TNs, effectively increased the diagnostic efficacy of TN evaluations by junior radiologists, and provided an objective assessment for the clinical and surgical management phases that follow.

Nomograms based on preoperative multimodal ultrasound of papillary thyroid carcinoma for predicting central lymph node metastasis.

OBJECTIVES: To establish a nomogram for predicting central lymph node metastasis (CLNM) based on the preoperative clinical and multimodal ultrasound (US) features of papillary thyroid carcinoma (PTC) and cervical LNs. METHODS: Overall, 822 patients with PTC were included in this retrospective study. A thyroid tumor ultrasound model (TTUM) and thyroid tumor and cervical LN ultrasound model (TTCLNUM) were constructed as nomograms to predict the CLNM risk. Areas under the curve (AUCs) evaluated model performance. Calibration and decision curves were applied to assess the accuracy and clinical utility. RESULTS: For the TTUM training and test sets, the AUCs were 0.786 and 0.789 and bias-corrected AUCs were 0.786 and 0.831, respectively. For the TTCLNUM training and test sets, the AUCs were 0.806 and 0.804 and bias-corrected AUCs were 0.807 and 0.827, respectively. Calibration and decision curves for the TTCLNUM nomogram exhibited higher accuracy and clinical practicability. The AUCs were 0.746 and 0.719 and specificities were 0.942 and 0.905 for the training and test sets, respectively, when the US tumor size was ≤ 8.45 mm, while the AUCs were 0.737 and 0.824 and sensitivity were 0.905 and 0.880, respectively, when the US tumor size was > 8.45 mm. CONCLUSION: The TTCLNUM nomogram exhibited better predictive performance, especially for the CLNM risk of different PTC tumor sizes. Thus, it serves as a useful clinical tool to supply valuable information for active surveillance and treatment decisions. KEY POINTS: • Our preoperative noninvasive and intuitive prediction method can improve the accuracy of central lymph node metastasis (CLNM) risk assessment and guide clinical treatment in line with current trends toward personalized treatments. • Preoperative clinical and multimodal ultrasound features of primary papillary thyroid carcinoma (PTC) tumors and cervical LNs were directly used to build an accurate and easy-to-use nomogram for predicting CLNM. • The thyroid tumor and cervical lymph node ultrasound model exhibited better performance for predicting the CLNM of different PTC tumor sizes. It may serve as a useful clinical tool to provide valuable information for active surveillance and treatment decisions.

Prognostic potential of layer-specific global longitudinal strain in patients with non-ST-segment elevated acute coronary syndrome and preserved left ventricular ejection fraction.

This study sought to investigate the prognostic potential of layer-specific global longitudinal strain (GLS) in predicting cardiac events among non-ST-segment elevated acute coronary syndrome (NSTE-ACS) patients with preserved LVEF. In this prospective study, we enrolled 160 consecutive NSTE-ACS patients with preserved LVEF (≥ 50%) who underwent successful percutaneous coronary intervention (PCI). Transthoracic two-dimensional echocardiography examinations were performed within 48 h of admission (before PCI). Cardiac events were defined as all-cause death, re-infarction, and hospitalization for heart failure. During a median follow-up of 30.2 months, 23 patients (14.4%) developed cardiac events. GLS for all three myocardial layers were reduced in patients with adverse outcome (all P < 0.001). Yet GLSendo (area under curves = 0.85) and GLSmid (area under curves = 0.83) showed relatively higher predictive power than GLSepi when identifying patients with cardiac events. The best cut-off value of GLSendo was - 20.8%, with a diagnostic sensitivity and specificity of 87% and 71% respectively. A significant increase in the risk of cardiac events development was shown among patients with impaired layer GLS (log-rank test, P < 0.001). In conclusion, NSTE-ACS patients with preserved LVEF, layer GLS assessed before PCI all had good abilities to predict cardiac events, which might provide more prognostic information against conventional echocardiographic risk factors.

Assessment of Left Ventricular Global Myocardial Work in Patients With Different Degrees of Coronary Artery Stenosis by Pressure-Strain Loops Analysis.

Global myocardial work (MW) analysis by pressure-strain loops (PSL) allows the non-invasive assessment of left ventricular (LV) function. We aimed to investigate the relationship between LV global MW and the degree of coronary artery stenosis in suspected coronary artery disease (CAD) patients with normal LV ejection fraction and regional wall motion. A total of 164 suspected CAD patients were divided into four groups according to coronary artery angiography. The results showed that global work efficiency (GWE) as the most significant predictor in all MW parameters had the optimal cut-off value of 94.5% for detecting moderate stenosis, and the sensitivity and specificity was 89.7% and 85.8%, respectively. A cut-off value of 94.0% for GWE was the most significant predictor of severe stenosis, and the sensitivity and specificity was 81.4% and 76.1%, respectively. In conclusion, LV global MW is a sensitive tool in detecting the degree of coronary artery stenosis and a potential valuable method to provide early diagnosis for CAD patients.

Targeted galectin-7 inhibition with ultrasound microbubble targeted gene therapy as a sole therapy to prevent acute rejection following heart transplantation in a Rodent model.

BACKGROUND: Despite significant advances in transplantation, acute cellular rejection (AR) remains a major obstacle that is most prevalent in the first months post heart transplantation (HT). Current treatments require high doses of immunosuppressive drugs followed by maintenance therapies that have systemic side effects including early infection. In this study, we attempted to prevent AR with a myocardial-targeted galectin-7-siRNA delivery method using cationic microbubbles (CMBs) combined with ultrasound targeted microbubble destruction (UTMD) to create local immunosuppression in a rat abdominal heterotopic heart transplantation acute rejection model. METHODS AND RESULTS: Galectin-7-siRNA (siGal-7) bound to CMBs were synthesized and effective ultrasound-targeted delivery of siGal-7 into target cells confirmed in vitro. Based on these observations, three transplant rat models were tested：①isograft (ISO); ② Allograft (ALLO) +UTMD; and ③ALLO + PBS. UTMD treatments were administered at 1, 3, 5, 7 days after HT. Galectin 7 expression was reduced by 50% compared to ALLO + PBS (p < 0.005), and this was associated with significant reductions in both galectin 7 and Interleukin-2 protein levels (p < 0.001). The ALLO + UTMD group had Grade II or less inflammatory infiltration and myocyte damage in 11/12 rats using International Society For Heart and Lung Transplantation grading, compared to 0/12 rats with this grading in the ALLO + PBS group at 10 days post HT (p < 0.001). CONCLUSIONS: Ultrasound-targeted galectin-7-siRNA knockdown with UTMD can prevent acute cellular rejection in the early period after allograft heart transplantation without the need for systemic immunosuppression. KEY WORDS: Microbubble, Acute Rejection, Heart Transplantation, Galectin-7, RNA.

Mesenchymal Stromal Cells from Patients with Cyanotic Congenital Heart Disease are Optimal Candidate for Cardiac Tissue Engineering.

Engineered heart tissues (EHTs) are regarded as being the most promising alternative to synthetic materials, and autologous mesenchymal stem cells (MSCs) are widely used as seeding cells. However, few studies have evaluated the feasibility of using MSCs from patients with cyanotic congenital heart disease (C-CHD) as seeding cells for EHTs, in comparison with cells from patients of acyanotic congenital heart disease (A-CHD). In the present study, we cultured MSCs from A-CHD and C-CHD patients in normoxia or hypoxia conditions, and compared their pro-angiogenic, anti-apoptotic and inflammation-modulatory potentials. In vivo, we seeded the cells into collagen patches conjugated with, or without, proangiogenic cytokines, which were used to repair the right ventricular outflow tract (RVOT) of rats. The in vitro results showed that C-CHD MSCs expressed higher levels of VEGFA and VEGFR2, and secreted more pro-angiogenic and anti-inflammatory cytokines under hypoxic conditions. On the other hand, apoptosis-related genes from C-CHD MSCs were modulated adaptably, converting these cells into an anti-apoptotic phenotype. In vivo studies demonstrated that in 4 weeks after RVOT reconstruction, cytokine-immobilized patches seeded with C-CHD MSCs exhibited preserved morphology, prolonged cell survival and enhanced angiogenesis compared to A-CHD MSCs. C-CHD MSCs that undergo "naturally hypoxic precondition" present a better cell source for EHTs, which would provide a promising individualized biomaterial for C-CHD patients.

Comparison of adipose­ and bone marrow­derived stem cells in protecting against ox­LDL­induced inflammation in M1­macrophage­derived foam cells.

Adipose­derived stem cells (ADSCs) and bone marrow­derived stem cells (BMSCs) are considered to be prospective sources of mesenchymal stromal cells (MSCs), that can be used in cell therapy for atherosclerosis. The present study investigated whether ADSCs co­cultured with M1 foam macrophages via treatment with oxidized low­density lipoprotein (ox­LDL) would lead to similar or improved anti­inflammatory effects compared with BMSCs. ADSCs, peripheral blood monocytes, BMSCs and ox­LDL were isolated from ten coronary heart disease (CHD) patients. After three passages, the supernatants of the ADSCs and BMSCs were collected and systematically analysed by liquid chromatography­quadrupole time­of­flight­mass spectrometry (6530; Agilent Technologies, Inc., Santa Clara, CA, USA). Cis­9, trans­11 was deemed to be responsible for the potential differences in the metabolic characteristics of ADSCs and BMSCs. These peripheral blood monocytes were characterized using flow cytometry. Following peripheral blood monocytes differentiation into M1 macrophages, the formation of M1 foam macrophages was achieved through treatment with ox­LDL. Overall, 2x106 ADSCs, BMSCs or BMSCs+cis­9, trans­11 were co­cultured with M1 foam macrophages. Anti­inflammatory capability, phagocytic activity, anti­apoptotic capability and cell viability assays were compared among these groups. It was demonstrated that the accumulation of lipid droplets decreased following ADSCs, BMSCs or BMSCs+cis­9, trans­11 treatment in M1 macrophages derived from foam cells. Consistently, ADSCs exhibited great advantageous anti­inflammatory capabilities, phagocytic activity, anti­apoptotic capability activity and cell viability over BMSCs or BMSCs+cis­9, trans­11. Additionally, BMSCs+cis­9, trans­11 also demonstrated marked improvement in anti­inflammatory capability, phagocytic activity, anti­apoptotic capability activity and cell viability in comparison with BMSCs. The present results indicated that ADSCs would be more appropriate for transplantation to treat atherosclerosis than BMSCs alone or BMSCs+cis­9, trans­11. This may be an important mechanism to regulate macrophage immune function.

Identification of a correlation between the sonographic appearance and molecular subtype of invasive breast cancer: A review of 311 cases.

PURPOSE: To identify the ultrasound and clinical features related to the different molecular subtypes of invasive breast cancer. METHODS: Sonographic and clinical data of 311 surgically confirmed breast cancer cases were retrospectively reviewed and compared based on various subtypes. RESULTS: Luminal A (LA) breast cancers were associated with a low histologic grade, spiculated margins, an echogenic rim and posterior acoustic attenuation. The human epidermal growth factor receptor 2-positive (HER2+) subtype was characterized by a high grade, indistinct and spiculated margins, enhanced posterior acoustics, calcifications, and vascularity. Triple negative breast cancers (TNBCs) were more likely to present with a high tumor grade, circumscribed and microlobulated margins, and the absence of an echogenic rim and calcifications; to be markedly hypoechoic; and to have posterior acoustic enhancement and hypovascularity. Luminal B (LB) cancers were more likely to be associated with an indistinct margin and relative vascularity. CONCLUSION: Our study demonstrated that the sonographic and clinical features of breast cancer were significantly correlated with the molecular subtype. The imaging findings of the different subtypes and their biological implications may provide additional auxiliary information for clinical diagnosis, systemic treatment and prognosis prediction.

In vivo degradation and neovascularization of silk fibroin implants monitored by multiple modes ultrasound for surgical applications.

BACKGROUND: In this paper we aimed to investigate the neovascularization and biodegradation of the silk fibroin in vivo using multiple modes ultrasound, including two-dimensional, three-dimensional and contrast-enhanced ultrasound by quantifying the echo intensity, volume and contrast enhancement of the silk fibroin implants. METHOD: A total of 56 male Wistar rats were randomly divided into two groups and 4%(w/v) silk hydrogels were injected subcutaneously at hind limb or upper back of the rats respectively to compare the biodegradation rate in different sites of the body. The implants were observed at day 0, 4, 8, 12, 16, 18, 20 with multiple modes ultrasound. RESULTS: The echo intensity of silk fibroin implants increased and the volume decreased gradually, and complete degradation was confirmed 18 and 20 days after subcutaneous implantation at the upper back and at the hind limb respectively. This demonstrated that the silk fibroin embedded in the upper back degraded slightly faster than that in the hind limb. Additionally, the neovascularization revealed by the contrast enhancement values of CEUS showed that there was a relatively low enhancement (< 5 dB) during day 4 to day 16, followed by moderate enhancement at day 18 (5-20 dB), and a significant enhancement at day 20 (> 40 dB). CONCLUSION: This study suggests that multiple modes ultrasound imaging could be an ideal method to evaluate the degradation and neovascularization of biomaterial implants in vivo for surgical applications.

Improved Left Ventricular Aneurysm Repair with Cell- and Cytokine-Seeded Collagen Patches.

BACKGROUND: Engineered heart tissues (EHTs) present a promising alternative to current materials for surgical ventricular restoration (SVR); however, the clinical application remains limited by inadequate vascularization postimplantation. Moreover, a suitable and economic animal model for primary screening is another important issue. METHODS: Recently, we used 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride chemistry (EDC) to initiate a strengthened, cytokine-conjugated collagenous platform with a controlled degradation speed. In vitro, the biomaterial exhibited an enhanced mechanical strength maintaining a porous ultrastructure, and the constant release of cytokines promoted the proliferation of seeded human mesenchymal stem cells (hMSCs). In vivo, with the hMSC-seeded, cytokine-immobilized patch (MSCs + GF patch), we performed modified SVR for rats with left ventricular aneurysm postmyocardial infarction (MI). Overall, the rats that underwent modified SVR lost less blood and had lower mortality. After 4 weeks, the rats repaired with this cell-seeded, cytokine-immobilized patch presented preserved cardiac function, beneficial morphology, enhanced cell infiltration, and functional vessel formation compared with the cytokine-free (MSC patch), cell-free (GF patch), or blank controls (EDC patch). Furthermore, the degradable period of the collagen patch in vivo extended up to 3 months after EDC treatment. CONCLUSIONS: EDC may substantially modify collagen scaffold and provide a promising and practical biomaterial for SVR.

In situ ultrasound imaging of silk hydrogel degradation and neovascularization.

Ultrasound (US) is a useful technique to monitor morphological and functional changes of biomaterial implants without sacrificing the animal. Contrast-enhanced ultrasound (CEUS) along with two-dimensional (2D) US were used to characterize the biodegradation and neovascularization of silk protein (8 wt%) hydrogel implants in rats. Cylinder-shaped silk hydrogel plugs were implanted into the space between the hind limb thigh muscles in Wistar rats (n = 6). The increase of echogenicity in 2D US revealed tissue-ingrowth-accompanied gel degradation over 18 weeks. The shape and size of the implanted gels remained qualitatively unchanged until week 15, as confirmed by Bland and Altman analysis and visualization of retrieved samples. Using CEUS, neovascularization was monitored by the presence of microbubbles in the gel area, and the dynamic vascularization process was indicated by the contrast enhancement values, which showed a relatively low level (< 5 dB) during weeks 1-8 and significantly increased levels (around 20 dB at week 15 and > 35 dB at week 18), suggesting that major vascularization had occurred in the gel implants by this time point. Histological and scanning electron microscopic analysis of explants revealed time-dependent increases in the pore size of the gel matrix, the presence of endothelial and red blood cells and the number of blood vessels in the gel implants, indicating that degradation and vascularization did occur in silk gel implants during the time period. The present study demonstrates the use of US imaging for monitoring of in vivo degradation and vascularization of silk implants in a non-destructive way. Copyright © 2015 John Wiley & Sons, Ltd.

Novel cell-penetrating peptide-loaded nanobubbles synergized with ultrasound irradiation enhance EGFR siRNA delivery for triple negative Breast cancer therapy.

The lack of safe and effective gene delivery strategies remains a bottleneck for cancer gene therapy. Here, we describe the synthesis, characterization, and application of cell-penetrating peptide (CPP)-loaded nanobubbles (NBs), which are characterized by their safety, strong penetrating power and high gene loading capability for gene delivery. An epidermal growth factor receptor (EGFR)-targeted small interfering RNA (siEGFR) was transfected into triple negative breast cancer (TNBC) cells via prepared CPP-NBs synergized with ultrasound-targeted microbubble destruction (UTMD) technology. Fluorescence microscopy showed that siEGFR and CPP were loaded on the shells of the NBs. The transfection efficiency and cell proliferation levels were evaluated by FACS and MTT assays, respectively. In addition, in vivo experiments showed that the expression of EGFR mRNA and protein could be efficiently downregulated and that the growth of a xenograft tumor derived from TNBC cells could be inhibited. Our results indicate that CPP-NBs carrying siEGFR could potentially be used as a promising non-viral gene vector that can be synergized with UTMD technology for efficient TNBC therapy.

Cadaveric cardiosphere-derived cells can maintain regenerative capacity and improve the heart function of cardiomyopathy.

OBJECTIVE: Cardiosphere-derived cells (CDCs) improve cardiac function and attenuate remodeling in ischemic and non-ischemic cardiomyopathy, and are currently obtained through myocardial biopsy. However, there is not any study on whether functional CDCs may be obtained through cadaveric autopsy with similar benefits in non-ischemic cardiomyopathy. METHODS: Cardiac tissues from human or mouse cadavers were harvested, plated at 4°C, and removed at varying time points to culture human CDCs (CLH-EDCs) and mouse CDCs (CM-CDCs). The differentiation and paracrine effects of CDCs were also assessed. Furthermore, intramyocardial injection of cadaveric CM-CDCs was performed in an induced dilated cardiomyopathy (DCM) model. RESULTS: With the extension of post mortem hours, the number of CLH-EDCs and CM-CDCs harvested from autopsy specimens decreased. The expressions of von Willebrand factor (VWF) and smooth muscle actin (SMA) on CDCs were gradually reduced, however, cardiac troponin I (TNI) expression increased in the 24 h group compared to the 0 h group. CLH-EDCs were also found to have similar paracrine function in the 24 h group compared to 0 h group. 8 weeks after CM-CDCs transplantion to the injured heart, mean left ventricular ejection fraction increased in both 0 h (64.99 ± 3.4%) and 24 h (62.99 ± 2.8%) CM-CDCs-treated groups as compared to the PBS treated group (53.64 ± 5.6 cm), with a decrease in left ventricular internal diastolic diameter (0.29 ± 0.08 cm and 0.32 ± 0.04 cm in 0 h and 24 h groups, vs. 0.41 ± 0.05 cm in PBS group). CONCLUSION: CDCs from cadaveric autopsy are highly proliferative and differentiative, and may be used as a source for allograft transplantation, in order to decrease myocardial fibrosis, attenuate left ventricular remodeling, and improve heart function in doxorubicin-induced non-ischemic cardiomyopathy.

Evaluation of Left Ventricular Regional Systolic Function Using Tissue Doppler Echocardiography After Mesenchymal Stem Cell Transplantation in Rabbits With Myocardial Infarction.

OBJECTIVES: The aim of this work was to assess left ventricular (LV) regional systolic function in rabbits with myocardial infarction after allogeneic mesenchymal stem cell (MSC) transplantation using quantitative tissue velocity imaging. METHODS: Thirty New Zealand White rabbits were assigned into 3 groups randomly: a sham-operated group (n = 10), a myocardial infarction (MI) group (n = 10), and a MSC transplantation group (n = 10). Mesenchymal stem cells (1 × 10(7) in total) were delivered into 5 spots around the left anterior descending artery (LAD) blood supply area via direct intramyocardial injections 1 hour after LAD ligation in the MSC group, whereas the MI group received the same amount of phosphate-buffered saline injections. Echocardiography was performed before LAD ligation and 1 day and 2 weeks after MSC transplantation, respectively. The peak systolic velocity (Vs) of each LV wall segment was measured. The myocardial slices were harvested for histologic staining after the last echocardiographic examination. RESULTS: The velocity curves for the LV myocardium before LAD ligation had a trend showing that the Vs value decreased gradually from basal to apical segments. The Vs values for the LV segments around the infarcted area in the MSC group decreased significantly compared with the sham group (P < .05) 1 day after MSC transplantation, whereas they increased significantly 2 weeks after MSC transplantation compared with 1 day after LAD ligation (P < .05). CONCLUSIONS: This study demonstrates that quantitative tissue velocity imaging may provide a promising approach to quantitatively assessing LV regional systolic function before and after MSC transplantation.

Three-dimensional transesophageal echocardiographic study of aortic-mitral valve coupling after coronary artery bypass grafting.

AIMS: To observe the geometric changes in aortic-mitral valve coupling (AMC) on three-dimensional transesophageal echocardiography and the factors leading to decreased mitral regurgitation (MR) after coronary artery bypass grafting (CABG). METHODS AND RESULTS: This study included 23 patients undergoing CABG for coronary artery disease. Fifteen patients with moderate to severe MR were separately analyzed to determine whether the severity of MR influences the geometric change in AMC. Echocardiographic examinations were performed pre- and post-CABG, and the studied parameters were obtained using Siemens Auto Valve Analysis software. The effective mitral regurgitant orifice area, left ventricular ejection fraction (LVEF), end-diastolic volume (EDV), and end-systolic volume (ESV) were measured pre- and post-CABG using Philips QLAB software. Ischemic MR, EDV, and ESV significantly decreased (all P < 0.05) and LVEF significantly improved (P < 0.05) after CABG. There were no significant differences between the pre- and post-CABG mitral valve (MV) parameters, aortic valve parameters, aortic-mitral annular angle, or centroid distance (all P > 0.05). Patients with moderate to severe MR exhibited the same results. CONCLUSION: The results of this study show that CABG does not cause an acute change in the geometry of AMC. Improved left ventricular function might increase the closing force of the MV, leading to decreased MR after CABG alone. MR significantly improved after CABG alone without MV treatment in the present study. This result may help to guide surgeons in choosing the optimal surgical methods for individual patients.