A cadaveric breast cancer tissue phantom for phase-contrast X-ray imaging applications

Background:As mammography X-ray imaging technologies advance and provide elevated contrast in soft tissues,a need has developed for reliable imaging phantoms for use in system design and component calibration.In advanced imaging modalities such as refraction-based methods,it is critical that developed phantoms capture the biological details seen in clinical precancerous and cancerous cases while minimizing artifacts that may be caused due to phantom production.This work presents the fabrication of a breast tissue imaging phantom from cadaveric breast tissue suitable for use in both transmission and refraction-enhanced imaging systems.Methods:Human cancer cell tumors were grown orthotopically in nude athymic mice and implanted into the fixed tissue while maintaining the native tumor/adipose tissue interface.Results:The resulting human–murine tissue hybrid phantom was mounted on a clear acrylic housing for absorption and refraction X-ray imaging.Digital breast tomosynthesis was also performed.Conclusion:Both attenuation-based imaging and refraction-based imaging of the phantom are presented to confirm the suitability of this phantom's use in both imaging modalities.

Anti-tumor effects of polybutylcyanoacrylate nanoparticles of diallyl trisulfide on orthotopic transplantation tumor model of hepatocellular carcinoma in BALB/c nude mice

Background Hepatocellular carcinoma （HCC） ranked the second among the causes of cancer mortality in China since the 1990s. Up to now, medication still plays an important role in the treatment of HCC. The therapies based on the allicin as a potential chemopreventive analog although is in its infancy at the present time, may have a significant role in the future management of HCC. Diallyl trisulfide （DATS） is a natural compound derived from garlic. In this study, we investigated the inhibitory effects of hepatic targeted polybutylcyanoacrylate nanoparticles of diallyl trisulfide （DATS-PBCA-NP） on orthotopic transplanted HepG2 hepatocellular carcinoma in nude mice. Methods DATS-PBCA-NP were detected by transmission electron microscope （TEM） and high-performance liquid chromatography （HPLC）. The orthotopic transplantation HCC models were established by implanting HCC HepG2 xenograft bits under the envelope of the mice liver. Successful models （n=29） were divided into 4 groups： normal saline （NS）, empty nanoparticles （EN）, DATS and DATS-PBCA-NP were intravenously administered to the mice respectively for 2 weeks. In vivo antitumor efficacy was evaluated by the measurement of tumor volume. Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling （TUNEL） assay and protein levels of apoptosis and cell proliferation proteins by immunoblotting in tumor tissues were performed to elucidate the possible mechanism. Results DATS-PBCA-NP possessed smooth and round appearance, dispersed well, and released in vitro in accord with double phase kinetics model. DATS-PBCA-NP changed the tissue/organ distribution of DATS in vivo. The successful rate of tumor implantation was 100%. Intravenous administration of DATS-PBCA-NP significantly retarded the growth of orthotopically transplanted hepatoma in BALB/c nude mice （compared with the other three groups, all P〈0.05） without causing weight loss （P〉0.05）. TUNEL staining showed that the tumors from DATS-PBCA-NP treated mice exhibited a markedly higher apoptotic index compared with control tumors. Western blot analysis of tumor tissue revealed that the down-regulated expression of proliferation cell nuclear antigen （PCNA） and Bcl-2 proteins in DATS-PBCA-NP group, and there were no significant differences in the expression of Fas, FasL and Bax proteins among the four groups （P〉0.05）. Conclusions DATS-PBCA-NP has good prolonged release effect in vivo and hepatic-targeted activity, and significant anti,tumor effect on the orthotopic transplantation HCC model in mice in association with the suppression of proliferation and the induction of apoptosis of tumor cells. These advantages are probably due to their liver targeting characteristics and consequently bring a higher anti-tumor activity.