Journal Article

Xen5, Xen 5, Pseudomonas aeruginosa

The ability of brominated furanones and other furanone compounds with 2(3H) and 2(5H) cores to inhibit bacterial adhesion of surfaces as well deactivate (destroy) them has been previously reported. The furanone derivatives 4-(2-(2-aminoethoxy)-2,5-dimethyl-3(2H)-furanone and 5-(2-(2-aminoethoxy)-ethoxy)methyl)-2(5H)-furanone were synthesized in our laboratory. These furanone derivatives were then covalently immobilized onto poly(styrene-co-maleic anhydride) (SMA) and electrospun to fabricate nonwoven nanofibrous mats with antimicrobial and cell-adhesion inhibition properties. The electrospun nanofibrous mats were tested for their ability to inhibit cell attachment by strains of bacteria commonly found in water ( Klebsiella pneumoniae Xen 39, Staphylococcus aureus Xen 36, Escherichia coli Xen 14, Pseudomonas aeruginosa Xen 5, and Salmonella tymphimurium Xen 26). Proton nuclear magnetic resonance spectroscopy ((1)H NMR), electrospray mass spectroscopy (ES-MS), and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) were used to confirm the structures of the synthesized furanones as well as their successful immobilization on SMA. To ascertain that the immobilized furanone compounds do not leach into filtered water, samples of water, filtered through the nanofibrous mats were analyzed using gas chromatography coupled with mass spectroscopy (GC-MS). The morphology of the electrospun nanofibers was characterized using scanning electron microscopy (SEM).

Journal Article

B16-F10-luc2, Melanoma, B16F10-luc2, IVIS

In-transit metastasis (ITM) is a unique manifestation of intralymphatic tumor dissemination, characterized by the presence of melanoma cells between the primary lesion and the draining regional lymph node basin that is clinically associated with poor prognosis. In this study, we aimed to establish an experimental animal model of melanoma ITM, as research progress in this field has been hampered by a lack of suitable experimental models. We reproduced melanoma ITM in a mouse hind limb by transplanting melanoma cells into the footpad of a mouse with lymphedema (LE). The tumor cells at the ITM site were highly proliferative, and mice with ITMs were more likely than control mice to develop distant lymph node and lung metastases. Peritumoral lymphatic vessels and tumor-associated blood vessels were increased in the primary tumor site of the LE mice. Our established ITM melanoma mouse model enabled us to clarify the molecular determinants and pathophysiology of ITM. This ITM model is also comparable to the unfavorable clinical behavior of melanoma ITM in humans and, moreover, underlined the importance of lymphangiogenic factors in the tumor dissemination through the lymphatic system.Journal of Investigative Dermatology advance online publication, 6 September 2012; doi:10.1038/jid.2012.274.

Journal Article

AngioSense

Real-time imaging of moving organs and tissues at microscopic resolutions represents a major challenge in studying the complex biology of live animals. Here we present a technique based on a novel stabilizer setup combined with a gating acquisition algorithm for the imaging of a beating murine heart at the single-cell level. The method allows serial in vivo fluorescence imaging of the beating heart in live mice in both confocal and nonlinear modes over the course of several hours. We demonstrate the utility of this technique for in vivo optical sectioning and dual-channel time-lapse fluorescence imaging of cardiac ischaemia. The generic method could be adapted to other moving organs and thus broadly facilitate in vivo microscopic investigations.

Journal Article

Xen31, Xen 31, MRSA, S. aureus, IVIS, Bioluminescence

Biofilms that develop on indwelling devices are a major concern in clinical settings. While removal of colonized devices remains the most frequent strategy for avoiding device-related complications, antibiotic lock therapy constitutes an adjunct therapy for catheter-related infection. However, currently used antibiotic lock solutions are not fully effective against biofilms, thus warranting a search for new antibiotic locks. Metal-binding chelators have emerged as potential adjuvants due to their dual anticoagulant/antibiofilm activities, but studies investigating their efficiency were mainly in vitro or else focused on their effects in prevention of infection. To assess the ability of such chelators to eradicate mature biofilms, we used an in vivo model of a totally implantable venous access port inserted in rats and colonized by either Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, or Pseudomonas aeruginosa. We demonstrate that use of tetrasodium EDTA (30 mg/ml) as a supplement to the gentamicin (5 mg/ml) antibiotic lock solution associated with systemic antibiotics completely eradicated Gram-positive and Gram-negative bacterial biofilms developed in totally implantable venous access ports. Gentamicin-EDTA lock was able to eliminate biofilms with a single instillation, thus reducing length of treatment. Moreover, we show that this combination was effective for immunosuppressed rats. Lastly, we demonstrate that a gentamicin-EDTA lock is able to eradicate the biofilm formed by a gentamicin-resistant strain of methicillin-resistant S. aureus. This in vivo study demonstrates the potential of EDTA as an efficient antibiotic adjuvant to eradicate catheter-associated biofilms of major bacterial pathogens and thus provides a promising new lock solution.

Journal Article

MDA-MB-231-D3H1, MDA-MB-231-luc-D3H1, IVIS, Bioware, Breast Cancer

The present study was undertaken to determine the anticancer efficacy of zerumbone (ZER), a sesquiterpene from subtropical ginger, against human breast cancer cells in vitro and in vivo. ZER treatment caused a dose-dependent decrease in viability of MCF-7 and MDA-MB-231 human breast cancer cells in association with G(2)/M phase cell cycle arrest and apoptosis induction. ZER-mediated cell cycle arrest was associated with downregulation of cyclin B1, cyclin-dependent kinase 1, Cdc25C, and Cdc25B. Even though ZER treatment caused stabilization of p53 and induction of PUMA, these proteins were dispensable for ZER-induced cell cycle arrest and/or apoptosis. Exposure of MDA-MB-231 and MCF-7 cells to ZER resulted in downregulation of Bcl-2 but its ectopic expression failed to confer protection against ZER-induced apoptosis. On the other hand, the SV40 immortalized mouse embryonic fibroblasts derived from Bax and Bak double knockout mice were significantly more resistant to ZER-induced apoptosis. ZER-treated MDA-MB-231 and MCF-7 cells exhibited a robust activation of both Bax and Bak. In vivo growth of orthotopic MDA-MB-231 xenografts was significantly retarded by ZER administration in association with apoptosis induction and suppression of cell proliferation (Ki-67 expression). These results indicate that ZER causes G(2)/M phase cell cycle arrest and Bax/Bak-mediated apoptosis in human breast cancer cells, and retards growth of MDA-MB-231 xenografts in vivo.