Therapeutic Angiogenesis for Ovarian Transplantation through Ultrasound-Targeted Microbubble Destruction

Platform-based BST-2-targeted microbubbles enhance HIFU therapy and effectively inhibit prostate cancer residual growth

OBJECTIVE

This study aims to evaluate the potential of BST2-targeted microbubble-facilitated HIFU therapy for prostate cancer (PCa), and to elucidate the mechanisms of synergistic tumor suppression in residual lesions.

METHODS

The specificity of BST-2 expression in PCa tumor endothelial cells was established using a cellular co-culture method. The targeting efficacy of Anti-BST-2 antibody-conjugated microbubbles (BST-2-MB) was evaluated both in vitro and in vivo. The therapeutic outcomes of BST-2-MB-augmented HIFU (High-Intensity Focused Ultrasound) for PCa in Balb/c mice were compared with those of non-targeted microbubbles and HIFU alone. Changes in the immunological microenvironment and modulation of BST-2-related oncogenic pathways in residual tumors were analyzed using Western Blot, immunofluorescence, flow cytometry, and ELISA.

RESULTS

BST-2 is highly expressed in PCa vascular endothelial cells, and BST-2-MBs show strong targeting efficacy. HIFU combined with BST-2-MB achieved larger ablation volumes and potent inhibition of residual tumor growth. This treatment induced more immunogenic cell death (ICD), DC maturation, and CD8+ T cell infiltration, and significantly downregulated the expression of BST-2, EGFR, pSTAT3, and pErk1/2 compared to other treatments.

CONCLUSION

BST-2-MB combined with HIFU therapy demonstrates a superior synergistic antitumor effect in PCa, effectively inhibiting residual tumors, which offers a novel strategy to enhance HIFU efficacy.

Allogeneic ovarian transplantation promotes the recovery of ovarian function in a rat model of cisplatin-induced premature ovarian failure

In this study, ovarian transplantation at different sites was performed on the rat model of premature ovarian failure, to explore the effect on the recovery of ovarian function, and to evaluate the application value in the treatment of ovarian function decline caused by the application of chemotherapy drugs. Thirty 2-month-old female SD rats of SPF grade were randomly divided into five groups, and both ovaries in the model group were treated with cisplatin (11 mg/kg) for modelling. After successful modelling, another 18 rats were taken as donor rats: group A was the control group, group B was the model group and group CDE was the experimental group. Ovary transplantation was performed using muscle, subcutaneous and renal peritoneum, respectively, and the rats were monitored for their general condition, estrous cycle and serum hormone levels after surgery. At the end of the observation period, the rats were executed and follicular development was observed.We confirm that all methods are carried out in accordance with the relevant guidelines and regulations.After 14 days of xenotransplantation, the general condition of the rats in the experimental group was better than that of the model group. Serum E2 and AMH levels were significantly higher than those in the model group (P = 0.000), and FSH levels were significantly lower than those in the control group (P = 0.000). Cisplatin can be used to successfully establish the rat POF model; the three transplantation sites (muscle, subcutaneous and renal peritoneum) selected in this experiment can make the transplanted ovarian tissue survive and successfully restore the endocrine function of the body, and the effect of which showed no significant difference.

Color Doppler Ultrasonographic Examination of Ovarian Grafts in Goats

The aim of this study was to evaluate the effectiveness of color Doppler ultrasonography for examination of the blood flow areas in superficial grafts after 7 or 15 days of heterotopic allotransplantation, comparing an in-ear subcutaneous area (IE) with an in-neck cervical intramuscular area (IN) in goats. To monitor the local blood flow in the graft areas, color Doppler signals were assessed daily until days seven and fifteen, when the left and right implants, respectively, were removed. The areas of blood flow around the transplanted ovarian fragments were significantly larger (p < 0.05) in the IE area compared to the IN area after 7 (IE: 4.70 ± 0.33A vs. IN: 3.67 ± 0.33B) and 15 (IE: 5.27 ± 0.21A vs. IN: 4.66 ± 0.22B) days of transplantation. A positive and significant correlation was observed between the area of blood flow and the day of assessment after 7 (IE: r = 0.43; p < 0.05) and 15 (IE: r = 0.52; p = 0.001; IN: r = 0.42; p = 0.001) days of transplantation. In conclusion, color Doppler ultrasonography can be used for real-time assessment of local blood perfusion in ovarian grafts, making it possible to identify alterations in the blood flow area in the period following a transplant procedure.

Sonodynamic effect based on vancomycin-loaded microbubbles or meropenem-loaded microbubbles enhances elimination of different biofilms and bactericidal efficacy

Aims

This study investigated vancomycin-microbubbles (Vm-MBs) and meropenem (Mp)-MBs with ultrasound-targeted microbubble destruction (UTMD) to disrupt biofilms and improve bactericidal efficiency, providing a new and promising strategy for the treatment of device-related infections (DRIs).

Methods

A film hydration method was used to prepare Vm-MBs and Mp-MBs and examine their characterization. Biofilms of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli were treated with different groups. Biofilm biomass differences were determined by staining. Thickness and bacterial viability were observed with confocal laser scanning microscope (CLSM). Colony counts were determined by plate-counting. Scanning electron microscopy (SEM) observed bacterial morphology.

Results

The Vm-MBs and Mp-MBs met the experimental requirements. The biofilm biomass in the Vm, Vm-MBs, UTMD, and Vm-MBs + UTMD groups was significantly lower than in the control group. MRSA and E. coli biofilms were most notably damaged in the Vm-MBs + UTMD group and Mp-MBs + UTMD group, respectively, with mean 21.55% (SD 0.08) and 19.73% (SD 1.25) remaining in the biofilm biomass. Vm-MBs + UTMD significantly reduced biofilm thickness and bacterial viability (p = 0.005 and p < 0.0001, respectively). Mp-MBs + UTMD could significantly decrease biofilm thickness and bacterial viability (allp < 0.001). Plate-counting method showed that the numbers of MRSA and E. coli bacterial colonies were significantly lower in the Vm-MBs + UTMD group and the Mp, Mp-MBs, UTMD, Mp-MBs + UTMD groups compared to the control group (p = 0.031). SEM showed that the morphology and structure of MRSA and E. coli were significantly damaged in the Vm-MBs + UTMD and Mp-MBs + UTMD groups.

Conclusion

Vm-MBs or Mp-MBs combined with UTMD can effectively disrupt biofilms and protectively release antibiotics under ultrasound mediation, significantly reducing bacterial viability and improving the bactericidal effect of antibiotics.

Comparison of angiogenic potential in vitrified vs. slow frozen human ovarian tissue

Vitrification of ovarian tissue is a promising alternative approach to the traditional slow freezing method. Few empirical investigations have been conducted to determine the angiogenic profiles of these two freezing methods. In this study we aimed to answer the question whether one of the cryopreservation methods should be preferred based on the secretion of angiogenic factors. Tissue culture with reduced oxygen (5%) was conducted for 48 h with samples of fresh, slow frozen/thawed and vitrified/rapid warmed ovarian cortex tissue from 20 patients. From each patient, tissue was used in all three treatment groups. Tissue culture supernatants were determined regarding cytokine expression profiles of angiogenin, angiopoietin-2, epidermal growth factor, basic fibroblast growth factor, heparin binding epidermal growth factor, hepatocyte growth factor, Leptin, Platelet-derived growth factor B, placental growth factor and vascular endothelial growth factor A via fluoroimmunoassay. Apoptotic changes were assessed by TUNEL staining of cryosections and supplemented by hematoxylin and eosin and proliferating cell nuclear antigen staining. Comparing the angiogenic expression profiles of vitrified/rapid warmed tissue with slow frozen/thawed tissue samples, no significant differences were observed. Detection of apoptotic DNA fragmentation via TUNEL indicated minor apoptotic profiles that were not significantly different comparing both cryopreservation methods. Vitrification of ovarian cortical tissue does not appear to impact negatively on the expression profile of angiogenic factors and may be regarded as an effective alternative approach to the traditional slow freezing method.

Formulation strategies to provide oxygen-release to contrast local hypoxia for transplanted islets

Islet transplantation refers to the transfusion of healthy islet cells into the diabetic recipients and reconstruction of their endogenous insulin secretion to achieve insulin independence. It is a minimally invasive surgery that holds renewed prospect as a therapeutic method for type 1 diabetes mellitus. However, poor oxygenation in the early post-transplantation period is considered as one of the major causes of islet loss and dysfunction. Due to the metabolism chacteristics, islets required a high supply of oxygen for cell survival while a hypoxia environment would lead to severe islet loss and graft failure. Emerging strategies have been proposed, including providing external oxygen and speeding up revascularization. From the perspective of formulation science, it is feasible and practical to protect transplanted islets by oxygen-release before revascularization as opposed to local hypoxia. In this study, we review the potential formulation strategies that could provide oxygen-release by either delivering external oxygen or triggering localized oxygen generation for transplanted islets.

The Significance of PAX8-PPARγ Expression in Thyroid Cancer and the Application of a PAX8-PPARγ-Targeted Ultrasound Contrast Agent in the Early Diagnosis of Thyroid Cancer

Objective. To investigate the significance of PAX8-PPARγ expression in thyroid cancer and the application of a PAX8-PPARγ-targeted ultrasound contrast agent in the early diagnosis of thyroid cancer. Methods. In this study, the expression of PAX8-PPARγ in thyroid cancer tissues, paracancer groups, and normal thyroid tissues was detected by western and immunohistochemical techniques; the effects of PAX8-PPARγ expression inhibition on thyroid cancer cell growth, clonogenic ability, and antiapoptosis were examined. The terminal carboxylactic acid/hydroxyacetic acid copolymer (PLGA-COOH) nanoparticles were prepared by the double emulsification solvent volatilization method. The in vitro cytotoxicity of the targeted contrast agent was detected by MTS and other methods; LD50 was used to evaluate its short-term in vivo toxicity after intraperitoneal injection in mice. Results. PAX8-PPARγ expression was significantly increased in thyroid cancer tissues, and the expression level of PAX8-PPARγ was closely correlated with TNM staging and lymph node metastasis ( $P$  < 0.05). In addition, PAX8-PPARγ was also expressed at high levels in thyroid cancer cell lines relative to normal thyroid cells. MTS experiments showed that the PAX8-PPARγ-targeted ultrasound nanocontrast agent had no significant toxic side effects on thyroid cells; countess observed that the contrast agent had no effect on cell survival and mortality; the LD50 assay showed that the targeted contrast agent had a wide safety range. Western blot showed the expression of caspase-3, BAX, and Bcl-2 in thyroid cancer cells, indicating that the nanocontrast agent has a good biosafety. In vitro targeting experiments showed that there were more nanospheres aggregated around the cells in the targeted contrast group. In vivo targeting imaging of nude mice revealed that the ultrasound signal was significantly enhanced in the targeted group compared with the nontargeted group after 20 min of LIFU irradiation. Conclusion. PAX8-PPARγ overexpression in thyroid cancer cell lines and thyroid cancer tissues promoted the proliferation and antiapoptotic ability of thyroid cancer cells and promoted the tumorigenic ability in nude mice in vivo. We successfully prepared a PAX8-PPARγ-targeted ultrasound nanocontrast agent, which has regular morphology, uniform size, and high stability, and its liquid-gas phase change can be promoted at lower temperature. Therefore, this contrast agent can achieve US-targeted imaging and temperature phase transition function, and may have enhanced ultrasound imaging potential.