Preparation of Hematoporphyrin-Poly(Lactic Acid) Nanoparticles Encapsulated Perfluoropentane/Salicylic Acid for Enhanced US/CEST MR Bimodal Imaging.

Background: Medical imaging modalities, such as magnetic resonance imaging (MRI), ultrasound, and fluorescence imaging, have gained widespread acceptance in clinical practice for tumor diagnosis. Each imaging modality has its own unique principles, advantages, and limitations, thus necessitating a multimodal approach for a comprehensive disease understanding of the disease process. To enhance diagnostic precision, physicians frequently integrate data from multiple imaging modalities, driving research advancements in multimodal imaging technology research. Methods: In this study, hematoporphyrin-poly (lactic acid) (HP-PLLA) polymer was prepared via ring-opening polymerization and thoroughly characterized using FT-IR, 1H-NMR, XRD, and TGA. HP-PLLA based nanoparticles encapsulating perfluoropentane (PFP) and salicylic acid were prepared via emulsion-solvent evaporation. Zeta potential and mean diameter were assessed using DLS and TEM. Biocompatibility was evaluated via cell migration, hemolysis, and cytotoxicity assays. Ultrasonic imaging was performed with a dedicated apparatus, while CEST MRI was conducted using a 7.0 T animal scanner. Results: We designed and prepared a novel dual-mode nanoimaging probe SA/PFP@HP-PLLA NPs. PFP enhanced US imaging, while salicylic acid bolstered CEST imaging. With an average size of 74.43 ± 1.12 nm, a polydispersity index of 0.175 ± 0.015, and a surface zeta potential of -64.1 ± 2.11 mV. These NPs exhibit excellent biocompatibility and stability. Both in vitro and in vivo experiments confirmed the SA/PFP@HP-PLLA NP's ability to improve tumor characterization and diagnostic precision. Conclusion: The SA/PFP@HP-PLLA NPs demonstrate promising dual-modality imaging capabilities, indicating their potential for preclinical and clinical use as a contrast agent.

The Effect and Mechanism of Curcumin Combined with Carboplatin Chemotherapy Promoting on Apoptosis of Lung Cancer HCC827 Cells.

Objective: To investigate the effect and mechanism of curcumin (CUR) killing lung cancer HCC827 cell spheres. Method: HCC827 cell spheres were cultured in serum-free medium, and the protein expression of CD133, SOX2, EpCAM, and ABCG2 was detected by western blot. MTT was used to evaluate the cell viability of HCC827 cell spheres and HCC827 cell after they were treated by 1, 2, 5, 10, and 20 mg/mL carboplatin (CBP) for 48 h. The inhibitory effects of 10 µM, 50 µM, 100 µM, and 200 µM CUR on GST (glutathione S-transferase) activity in HCC827 cell spheres were determined by colorimetry. The flow cytometry (FCM), western blot, qPCR, luciferase assay, and microscopy were used to detect the ROS levels, cell pelletization ability, ß-catenin, SOX2, and ABCG2 mRNA and the promoter activity of ß-catenin upon of HCC827 cell spheres treated with 200 µM CUR for 48 h. The HCC827 cell spheres were infected with ß-catenin adenovirus, and then cells were treated with 200 µM CUR (and/or no 5 mg/mL CBP) for 24 h. The mRNA and protein expression of ß-catenin, SOX2, and ABCG2 was detected by qPCR and western blot, and cell growth inhibition of HCC827 cell spheres was evaluated by MTT. Result: The expression of stem cells marker CD133, SOX2, EpCAM, and drug resistance-related gene ABCG2 mRNA is higher in HCC827 cell spheres, and HCC827 cell spheres resisted the killing effect of difference doses of CBP. The activity of GST of HCC827 cell spheres was inhibited by 10 µM, 50 µM, 100 µM, and 200 µM CUR. It was a dose-dependent manner. After 200 µM CUR had treated HCC827 cell spheres for 48 h, the level of ROS was significantly increased (P < 0.05), and the mRNA and protein expression of ß-catenin, SOX2, and ABCG2 and promoter activity of ß-catenin were notably decreased (P < 0.05), compared to the control group. Furthermore, the formed-sphere ability of HCC827 sphere was inhibited after cells were treated with 200 µM CUR. 200 µM CUR could suppress the proliferation of HCC827 cell spheres and induced cell apoptosis. The proliferation of HCC827 cell spheres was significantly inhibited, and cell apoptosis rate was increased by 200 µM CUR combined with 5 mg/mL CBP than by 200 µM CUR alone. Upregulation of ß-catenin by adenovirus partly reversed the effect of CUR inhibition of the expression of ß-catenin, SOX2, and ABCG2, compared to empty vector adenovirus group. Additionally, overexpression of ß-catenin significantly remitted the inhibitory effect of 200 µM CUR combined with 5 mg/mL CBP on the proliferation of HCC827 cell spheres. Conclusion: CUR inhibited the cell proliferation and stem cell trait and induced apoptosis in HCC827 cell spheres by the inhibition of GST activity and ß-catenin expression. CUR is expected to become a treatment for lung cancer and lung cancer stem cells.

Construction of novel amphiphilic chitosan-polylactide graft copolymer nanodroplets for contrast enhanced ultrasound tumor imaging.

In this experiment, a new amphiphilic chitosan-poly(lactide) graft copolymer was synthesized and characterized by IR, 1H-NMR, XRD, TGA. The obtained chitosan-poly (lactide) graft copolymer was used as the matrix material to prepare nanodroplets (NDs) encapsulating with liquid PFP by double-emulsion and solvent evaporation method. The resulting NDs were characterized by photon correlation spectroscopy and transmission electron microscopy (TEM). The biocompatibility was explored by cytotoxicity assay, cell migration assay and blood biochemistry analysis. The experiments of ultrasonic imaging in vitro and in vivo were carried out with a B-mode clinical ultrasound imaging system. The results of FI-IR and 1H-NMR confirmed the successful grafting reaction of polylactic acid(PLLA) to chitosan with a graft rate of 365%. The average size of the NDs was 101.1 ± 2.7 nm, with the polydispersity index (PDI) of 0.127 ± 0.020, and the zeta potential was -31.8 ± 1.5 mV. From the TEM results, NDs were highly dispersed and had a spherical shape with a distinct capsule structure. The NDs exhibited good stability during storage at 4°C. The NDs solution with different concentrations did not affect cell growth and showed good biocompatibility in cytotoxicity, cell migration and blood biochemistry studies. Under the irradiation of ultrasonic waves, the NDs formed an ultrasonic high signal, which could significantly enhance the ultrasound imaging of tumor tissue in vivo. Taken together, the NDs hold great potential for ultrasound imaging as a nanosized contrast agent.

MiR-223 promotes the doxorubicin resistance of colorectal cancer cells via regulating epithelial-mesenchymal transition by targeting FBXW7.

Although doxorubicin has become a key drug in cancer treatment, the resistance of colorectal carcinoma to doxorubicin is a major problem in clinical practice. F-box and WD repeat domain-containing 7 (FBXW7) plays important roles in human cancers and is one of the major causes of drug resistance. The miR-223/FBXW7 pathway has been reported to be a crucial clue to the mechanism of chemoresistance in many human cancers, such as gastric cancer, breast cancer, and non-small cell lung cancer. However, it is unclear whether similar mechanisms of doxorubicin resistance are involved in colorectal cancer (CRC). The aim of the current study was to evaluate the role of miR-223/FBXW7 pathway in chemosensitivity in different CRC cell lines and to investigate the relevant underlying mechanisms. We found that high levels of FBXW7 expression were associated with increased doxorubicin sensitivity in different CRC cell lines, and FBXW7 was regulated by miR-223. Overexpression of miR-223 decreased FBXW7 expression and the sensitivity of CRC cells to doxorubicin, while suppression of miR-223 had the opposite effect. Moreover, epithelial-mesenchymal transition (EMT) was proved to be regulated by miR-223/FBXW7 pathway and involved in the drug resistance. In conclusion, miR-223/FBXW7 axis regulates doxorubicin sensitivity through EMT in CRC, which may lead to the development of individualized treatment in clinical practice.