Comparision Between Sonodynamic Effects with Protoporphyrin IX and Hematoporphyrin on the Cytoskeleton of Ehrlich Ascites Carcinoma Cells

Multifunctional Theranostic Nanoparticles for Enhanced Tumor Targeted Imaging and Synergistic FUS/Chemotherapy on Murine 4T1 Breast Cancer Cell

Purpose

Triple negative breast cancer (TNBC) is challenging for effective remission due to its very aggressive, extremely metastatic and resistant to conventional chemotherapy. Herein, a multifunctional theranostic nanoparticle was fabricated to enhance tumor targeted imaging and promote focused ultrasound (FUS) ablation and chemotherapy and sonodynamic therapy (SDT). A multi-modal synergistic therapy can improve the therapeutic efficacy and prognosis of TNBC.

Methods

AS1411 aptamer modified PEG@PLGA nanoparticles encapsulated with perfluorohexane (PFH) and anti-cancer drug doxorubicin (DOX) were constructed (AS1411-DOX/PFH-PEG@PLGA) to enhance tumor targeted imaging to guide ablation and synergistic effect of FUS/chemotherapy. FUS was utilized to trigger the co-release of doxorubicin and simultaneously PFH phase transition and activate DOX for SDT effect. The physicochemical, phase-changeable imaging capability, biosafety of nanoparticles and multi-mode synergistic effects on growth of TNBC were thoroughly evaluated in vivo and in vitro.

Results

The synthesized AS1411-DOX/PFH-PEG@PLGA (A-DPPs) nanoparticles are uniformly round with an average diameter of 306.03 ± 5.35 nm and the zeta potential of −4.05 ± 0.13 mV, displaying high biosafety and FUS-responsive drug release in vitro and in vivo. AS1411 modified NPs specifically bind to 4T1 cells and elevate the ultrasound contrast agent (UCA) image contrast intensity via PFH phase-transition after FUS exposure. Moreover, the combined treatment of A-DPPs nanoparticles with FUS exhibited significantly higher apoptosis rate, stronger inhibitory effect on 4T1 cell invasion in vitro, induced more reactive oxygen species (ROS), and enhanced anti-tumor effect compared to a single therapy (p < 0.05). Additionally, the joint strategy resulted in more intense cavitation effect and larger ablated areas and reduced energy efficiency factor (EEF) both in vitro and in vivo.

Conclusion

The multifunctional AS1411-DOX/PFH-PEG@PLGA nanoparticles can perform as a marvelous synergistic agent for enhanced FUS/chemotherapy, promote real-time contrast enhanced US imaging and improve the therapeutic efficacy and prognosis of TNBC.

Sonodynamic effect of an anti-inflammatory agent--emodin on macrophages

Emodin has been used as an anti-inflammatory agent and inflammation is a crucial feature of atherosclerosis. Here, we investigated the sonodynamic effect of emodin on macrophages, the pivotal inflammatory cells in atherosclerotic plaque. THP-1 derived macrophages were cultured with emodin and exposed to ultrasound. Six hours later, unlike the cells treated for 5 and 10 min, the viability of cells treated for 15 min decreased significantly and the cells showed typical apoptotic chromatin fragmentation. The percentage of apoptotic and necrotic cells in the sonodynamic therapy (SDT) group was higher than that in the ultrasound group. Two hours after treatment for 15 min, the cytoskeleton lost its original features as the filaments dispersed and the cytoskeletal proteins aggregated. The percentage of cells with disturbed cytoskeletal filaments in the SDT group was higher than that in the ultrasound group. These results suggest emodin has a sonodynamic effect on macrophages and might be used as a novel sonosensitizer for SDT for atherosclerosis.

Cancer treatment using an optically inert Rose Bengal derivative combined with pulsed focused ultrasound

Pulsed high intensity focused ultrasound (HIFU) has been combined with a photo-insensitive Rose Bengal derivative (RB2) to provide a synergistic cytotoxicity requiring the presence of both ultrasonic cavitation and drug. In vitro tests have shown that a short treatment (less than 30 s) of pulsed HIFU with peak negative pressure >7 MPa (~27 W acoustic power at 1.4 MHz) destroys >95% of breast cancer cells MDA-MB-231 in suspension with >10 μM of the compound. Neither the pulsed HIFU nor the RB2 compound was found to have any significant impact on the viability of the cells when used alone. Introducing an antioxidant (N-acetylcysteine) reduced the effectiveness of the treatment. In vivo tests using these same cells growing as a xenograft in nu/nu mice were also done. An ultrasound contrast agent (Optison) and lower frequency (1.0 MHz) was used to help initiate cavitation at the tumor site. We were able to demonstrate tumor regression with cavitation alone, however, addition of RB2 compound injected i.v. yielded a substantial synergistic improvement.