Prussian blue nanoparticles coated with tumor cell membranes for precise photothermal therapy and subsequent inflammation reduction.

The utilization of photothermal agents (PTAs) in photothermal therapy (PTT) is faced with challenges such as immune clearance and inadequate concentration, which consequently result in residual tumors and an increased risk of recurrence and metastasis. Conversely, excessive treatment can lead to heightened inflammation and inevitable harm to adjacent healthy tissues. To address these issues, we developed a nanosystem (M@PB) consisting of Prussian blue coated with tumor cell membrane for precise photothermal therapy (PTT) and subsequent reduction of inflammation. This system not only evades immune attack due to the homologous biological characteristics of the encapsulating cell membrane but also exhibits active targeting capabilities towards homologous tumors. Furthermore, it effectively reduces excessive phototoxicity by leveraging the distinctive photothermal and anti-inflammatory characteristics of PB nanoparticles. The resulting M@PB nanosystem demonstrates effective photothermal ablation under 808 nm laser irradiation while mitigating the inflammatory response through inhibiting of local production of inflammatory mediators. Our study provides valuable insights into achieving targeted PTT with high efficiency while minimizing post-treatment inflammatory responses.

The effect of gel pads on the measurement of breast superficial lesions by shear wave elastography.

OBJECTIVE: This study aimed to compare the repeatability and diagnostic efficiency of shear wave elastography (SWE) while using coupling gel and gel pads in the diagnosis of superficial breast lesions. METHODS: Two experienced sonographers, trained in SWE, used different methods to perform the maximum Young's modulus (Emax) measurement of the lesion while using coupling gel SWE and gel pad SWE at different time points. All 80 lesions were in the superficial layer of the breast. The interclass correlation coefficient (ICC) was calculated to evaluate the intraobserver and interobserver repeatability. Meanwhile, the receiver operating characteristic curve (ROC curve) was used to calculate the sensitivity, specificity and area under the curve of the two methods. RESULTS: In the 80 breast lesions, the intraobserver and interobserver reproducibility of SWE measurements using coupling gel were considered good, and the ICCs were 0.728 (95% CI: 0.509-0.813) and 0.702 (95% CI: 0.492-0.795), respectively. The intraobserver and interobserver reproducibility of the SWE measured by the gel pad were also considered good, and the ICCs were 0.745 (95% CI: 0.501-0.801) and 0.713 (95% CI: 0.498-0.802), respectively. The sensitivity, specificity and area under the curve were 0.711 and 0.737, 0.929 and 0.905, and 0.873 and 0.878, respectively. CONCLUSIONS: In the SWE measurement of superficial breast lesions, the use of a gel pad does not affect the repeatability and diagnostic efficiency of the measurement.

The use of gel pads does not affect repeatability and diagnostic efficiency but also improves the near-field resolution of images.The gel pad has certain advantages in the observation of superficial lesions.

[Effect of low-dose focused ultrasound pre-irradiation versus microbubbles for enhancing high-intensity focused ultrasound ablation of VX2 hepatic tumor in rabbits].

OBJECTIVE: To compare the effect of low-dose focused ultrasound pre-irradiation and microbubbles for enhancing the ablation effect of high intensity focused ultrasound (HIFU) on VX2 hepatic tumor in rabbits. METHODS: Fifty-five rabbits bearing VX2 hepatic tumor were randomly divided into low-dose pre-irradiation + HIFU ablation group, microbubbles+HIFU ablation group, and HIFU ablation group for corresponding treatments. The pathological changes in the tumors after low-dose irradiation, time for HIFU ablation, tumor volume with coagulative necrosis, energy efficiency factor (EEF), pathological changes in the ablated tumor, and sound channel of HIFU ablation were observed. RESULTS: Tumor cell edema, vacuolar changes in the cytoplasm and tumor interstitial vascular congestion were observed 24 h after low-dose pre-irradiation. The ablation time were significantly shorter, coagulative necrosis volume was larger, and EEF was lower in low-dose irradiation + HIFU ablation group and microbubbles+HIFU ablation group than in simple HIFU ablation group (P<0.05), but the differences between the former two groups were not significant. The effectiveness and stability of the synergistic effect of low-dose pre-irradiation were inferior to microbubbles, but the former ensured a better safety of the sound channel. CONCLUSION: Low-dose irradiation has comparable synergistic effect in HIFU with microbubbles with such advantages as non-invasiveness, high concentration and good safety, and can be a potentially new method to enhance the efficiency of HIFU.