Tracking Osteoarthritis Progress through Cationic Nanoprobe-Enhanced Photoacoustic Imaging of Cartilage.

A major obstacle in osteoarthritis (OA) theranostics is the lack of a timely and accurate monitoring method. It is hypothesized that the loss of anionic glycosaminoglycans (GAGs) in articular cartilage reflects the progression of OA. Thus, this study investigated the feasibility of photoacoustic imaging (PAI) applied for monitoring the in vivo course of OA progression via GAG-targeted cationic nanoprobes. The nanoprobes were synthesized through electrostatic attraction between poly-l-Lysine and melanin (PLL-MNPs). Cartilage explants with different concentrations of GAGs incubated with PLL-MNPs to test the relationship between GAGs content and PA signal intensity. GAG activity was then evaluated in vivo in destabilization of the medial meniscus (DMM) surgically-induced mouse model. To track OA progression over time, mice were imaged consistently for 10 weeks after OA-inducing surgery. X-ray was used to verify the superiority of PAI in detecting OA. The correlation between PAI data and histologic results was also analyzed. In vitro study demonstrated the ability of PLL-MNPs in sensitively detecting different GAGs concentrations. In vivo PAI exhibited significantly lower signal intensity from OA knees compared to normal knees. More importantly, PA signal intensity showed serial reduction over the course of OA, while X-ray showed visible joint destruction until 6 weeks. A decrease in GAGs content was confirmed by histologic examinations; moreover, histologic findings were well correlated with PAI results. Therefore, using cationic nanoprobe-enhanced PAI to detect the changes in GAG contents provides sensitive and consistent visualization of OA development. This approach will further facilitate OA theranostics and clinical translation. STATEMENT OF SIGNIFICANCE: The study of in vivo monitoring osteoarthritis (OA) is of high significance to tracking the trajectory of OA development and therapeutic monitoring. Here, we developed a cartilage-targeted cationic nanoprobe, poly-l-Lysine-melanin nanoparticles (PLL-MNPs), enhancing photoacoustic imaging (PAI) to monitor the progression of OA. The in vitro study demonstrated the ability of PLL-MNPs to detect different concentrations of GAGs with high sensitivity. We found that the contents of GAGs in vivo steadily decreased from the development of OA initial-stage to the end-point of our investigation via PAI; it reflected the course of OA in living subjects with high sensitivity. These results allow for further development in various aspects of OA research. It has potential for clinical translation and has a great impact on personalized medicine.

Enhancement Effect of Microbubble-Enhanced Ultrasound in Microwave Ablation in Rabbit VX2 Liver Tumors.

OBJECTIVES: One reason for the high recurrence and metastatic rates of tumors such as hepatocellular carcinoma (HCC) treated by microwave ablation (MWA) is the presence of residual foci in the tumor due to heat sink effect. Microbubble-enhanced ultrasound (MEUS) can noninvasively disrupt and block the tumor blood perfusion and has the potential to overcome the heat sink effect and enhance the therapeutic effect of MWA. The study aimed at evaluating the potential additional benefit of microbubble-enhanced ultrasound (MEUS) in hepatocellular carcinoma (HCC) treated by microwave ablation (MWA). METHODS: In this study, a new strategy of combining MWA with MEUS for treating HCC was proposed. Twenty-four rabbits with VX2 tumors in livers were randomly divided into MEUS + MWA, MEUS alone, MWA alone, and blank control groups, respectively (n = 6). In the MEUS group, the tumors were directly exposed to therapeutic ultrasound for 5 min with a concurrent intravenous injection of microbubbles (0.1 ml/kg diluted into 5 ml saline). In the MWA group, the tumors were treated by MWA for 1 min. In the MEUS + MWA group, tumors were ablated by MWA for 1 min after ultrasound cavitation enhanced by microbubbles as in the MEUS group. In the blank control group, the tumors received probe sham and intravenous saline. Contrast-enhanced ultrasound (CEUS) was performed before treatment and immediately after treatment to display the size, shape, and contour of the tumors. Throughout the treatment process, the local temperature of the treatment area was detected by a temperature needle punctured into the tumor. The blood samples of animals were obtained after treatment for evaluating the liver function. Tumor cell necrosis and apoptotic rates were observed after treatment by histological examination. RESULTS: CEUS showed that although perfusion defects appeared in all the treatment groups, especially in the MEUS + MWA group, there was no significant difference between the two groups on the volumes of perfusion defects, which were 1.78 ± 0.31 (cm3) in the MWA group and 1.84 ± 0.20 (cm3) in the combined group (P < 0.01). The time to reach the peak temperature of the treatment area was 21.7 ± 5.0 (s) in the MWA group and 10.3 ± 5.0 (s) in the MEUS + MWA group (P < 0.01). The time to reach the peak temperature of the treatment area was 21.7 ± 5.0 (s) in the MWA group and 10.3 ± 5.0 (s) in the MEUS + MWA group (P < 0.01). The time to reach the peak temperature of the treatment area was 21.7 ± 5.0 (s) in the MWA group and 10.3 ± 5.0 (s) in the MEUS + MWA group (. CONCLUSIONS: These results suggested MEUS treatment alone may significantly reduce tumor blood perfusion and led to a sharp rise in the local temperature of the treatment area to a higher PT using MEUS + MWA with higher rates of necrosis and apoptosis of cancer cells without severe liver function damage, which might be a safe strategy for treating HCC.

Therapeutic options and drug delivery strategies for the prevention of intrauterine adhesions.

Intrauterine adhesions (IUAs) are bands of fibrous tissue that form in the endometrial cavity and associated with the increased risk of abnormal menstruation, recurrent pregnancy loss, secondary infertility, and pregnancy complications. Physical barriers, including intrauterine device and hydrogel, were clinical available to prevent the post-operational IUAs. But physically separation of the injured endometrium relies on the own limited healing power and often ends with recurrence. In recent years, the mechanisms driving IUAs treatment has validated the application of hormones, and further stem cell therapy has also led to the development of novel therapeutic agents with promising efficacy in pre-clinical and initial clinical studies. Still, it is challenging to delivery the therpaeutic factors to the injured uterus. Herein, in this review, we discuss the traditional intervention methods for the prevention of IUAs, as well as novel therapeutics and delivery strategies that will most likely change the treatment paradigms for better clinical outcomes. The combination strategy that using physical barriers as the delivery carriers for therapeutics might provide new alternatives for the prevention of IUAs.

Effect of Ultrasound Combined With Microbubble Therapy on Interstitial Fluid Pressure and VX2 Tumor Structure in Rabbit.

Interstitial fluid pressure (IFP) in tumor tissue is significantly higher than that in normal tissue, which reduces the effectiveness of therapeutic drugs. There are several methods to decrease the IFP, such as normalizing blood vessel, decreasing hyaluronic acid and collagen fiber content in the extracellular matrix (ECM), and recovering lymphatic function. Reducing tumor IFP might be developed as a novel approach in cancer therapy. In this study, we aimed to elucidate the relationship between ultrasound combined with microbubble therapy and IFP, and the associated mechanism. VX2 tumor in rabbit was treated with ultrasound combined with microbubbles at different intensities. The IFP was measured using the wick-in-needle (WIN) method. The collagen and reticular fibers were stained by Masson and Gordon-Sweets, respectively. The results showed that low-frequency non-focus ultrasound combined with microbubbles therapy influences the IFP in tumor tissues; low-frequency non-focus ultrasound with low pressure increased the IFP, whereas middle-high pressure decreased the IFP. The results showed that the structure and content of collagen and reticular fibers in tumor tissue were rarely influenced by the treatment. Our study provides a novel approach of reduced IFP antitumor therapy.

Ambidextrous Approach To Disrupt Redox Balance in Tumor Cells with Increased ROS Production and Decreased GSH Synthesis for Cancer Therapy.

An effective steady-state redox balance is maintained in cancer cells, allowing for protection against oxidative stress and thereby enhancing cell proliferation and tumor growth. Disruption of this redox balance would increase the cellular content of reactive oxygen species (ROS) and potentiate oxidative stress-induced cell death in tumor cells, thus representing an effective strategy for cancer treatment. Glutathione (GSH) is a major reducing agent, and its cellular levels are determined at least partly by the availability of cysteine via xCT (SLC7A11)-mediated entry of cystine into cells. We developed a nanoplatform using ZnO nanoparticles (NPs) as a carrier, loaded with salicylazosulfapyridine (SASP), and stabilized with DSPE-PEG, to form ultra-small NPs (SASP/ZnO NPs). The goal of this NP strategy is to disrupt the redox balance in cells by two mechanisms: increased generation of ROS and decreased synthesis of GSH. Such an approach would be effective in killing tumor cells. As expected, the SASP/ZnO NPs enhanced ROS production because of ZnO and impaired GSH synthesis because of SASP-induced inhibition of xCT (SLC7A11) transport function. As a consequence, treatment of tumor cells with SASP/ZnO NPs in vitro and in vivo resulted in a synergistic disruptive effect on redox balance in tumor cells and induced cell death and decreased tumor growth. This ambidextrous approach has potential in cancer therapy by combining two complementary pathways to disrupt the redox balance in tumor cells.

Penetration of different molecule sizes upon ultrasound combined with microbubbles in a superficial tumour model.

Ultrasound combined with microbubbles (USMB) has been extensively applied to enhance drug and gene targeting delivery. However, the accumulation and distribution of particle size in the range of 5-30 nm (nano drug) to the tumour and the effects of intratumoral vascular density on permeability have been rarely reported. This study investigated Evans blue (EB) and fluorescein isothiocyanate-labelled dextran (FITC-dextran) distribution in tumour tissue upon USMB with various molecular sizes (3.7 nm and 30.6 nm). USMB increased the penetration of molecules with sizes of 5-20 nm in the whole tumour tissue, especially on the rim. For a molecule with sizes of 30.6 nm, USMB only increased penetration around the rim of the tumour with minimal improvement in the central of tumour. USMB enhanced the permeability of tumour tissue and increased tumour cells dose exposure without affecting tumour blood perfusion or microvessel density. The current study served as the foundation of parameter preference for therapeutic USMB drug delivery.

Correlation of virtual touch tissue quantification and liver biopsy in a rat liver fibrosis model.

Liver fibrosis assessment is very important to the treatment of chronic liver disease. In the present study, Virtual Touch Tissue Quantification (VTQ) and eSie Touch™ elasticity imaging techniques were used to examine the rat liver fibrosis model. Rat liver fibrosis was induced with thioacetamide and the degree of liver fibrosis was determined using pathological diagnosis as a gold standard. The right lobe of the liver was also examined with the VTQ and eSie Touch™ techniques. The VTQ and serological results were correlated and analyzed. The results were compared with those obtained from liver biopsies to investigate the accuracy and diagnostic value of eSie Touch™ and VTQ on the classification of liver fibrosis in rats. A total of 30 successful modeling cases were obtained, with a success rate of 86%. The mean acoustic radiation force impulse (ARFI) elastography­VTQ values were 1.08, 1.51, 1.88 and 2.50 m/sec for the normal and F1/F2, F3 and F4 fibrosis groups, respectively. A significant correlation (r = 0.969) was identified between the ARFI measurements and the degree of fibrosis assessed by pathological examination (P<0.001). The histological staging results correlated with those of the eSie Touch™ elasticity imaging of the biopsy site (r = 0.913, P<0.001). The predictive values of ARFI for various stages of fibrosis were as follows: F≥1 and 2 ­ cut­off >1.250 m/sec (when Vs >1.250 m/sec, the pathological grading was ≥F1/F2) [Area under receiver operating characteristic (AUROC) = 1.00], F≥3 ­ cut­off >1.685 m/sec (when Vs >1.685 m/sec, the pathological grading was ≥F3; AUROC = 1.00) and F≥4 ­ cut­off >2.166 m/sec (when Vs >2.166 m/sec, the pathological grading is cirrhosis; AUROC = 1.00). In conclusion, the eSie Touch™ elasticity imaging and VTQ techniques may be successfully adopted to assess the extent of liver stiffness. These techniques are expected to replace liver biopsy.