Citation Details

Journal Article

IntegriSense, Animals; Antigens, CD/*biosynthesis/*metabolism; Flow Cytometry/methods; Glioma/metabolism; Glycoproteins/*biosynthesis/*metabolism; Humans; Hybridomas/metabolism; Mice; Mice, Transgenic; Models, Biological; Neoplasm Metastasis; Neoplasm Transplantation; Neoplasms/*metabolism; Neoplastic Stem Cells; Peptides/*metabolism; Recurrence

BACKGROUND: Cancer stem cells are thought to play a pivotal role in tumor maintenance, metastasis, tumor therapy resistance and relapse. Hence, the development of methods for non-invasive in vivo detection of cancer stem cells is of great importance. METHODOLOGY/PRINCIPAL FINDINGS: Here, we describe successful in vivo detection of CD133/prominin, a cancer stem cell surface marker for a variety of tumor entities. The CD133-specific monoclonal antibody AC133.1 was used for quantitative fluorescence-based optical imaging of mouse xenograft models based on isogenic pairs of CD133 positive and negative cell lines. A first set consisted of wild-type U251 glioblastoma cells, which do not express CD133, and lentivirally transduced CD133-overexpressing U251 cells. A second set made use of HCT116 colon carcinoma cells, which uniformly express CD133 at levels comparable to primary glioblastoma stem cells, and a CD133-negative HCT116 derivative. Not surprisingly, visualization and quantification of CD133 in overexpressing U251 xenografts was successful; more importantly, however, significant differences were also found in matched HCT116 xenograft pairs, despite the lower CD133 expression levels. The binding of i.v.-injected AC133.1 antibodies to CD133 positive, but not negative, tumor cells isolated from xenografts was confirmed by flow cytometry. CONCLUSIONS/SIGNIFICANCE: Taken together, our results show that non-invasive antibody-based in vivo imaging of tumor-associated CD133 is feasible and that CD133 antibody-based tumor targeting is efficient. This should facilitate developing clinically applicable cancer stem cell imaging methods and CD133 antibody-based therapeutics.

Journal Article

Prosense, IVIS, Animals; Biocompatible Materials/*diagnostic use; Diagnostic Imaging/*methods; *Fluorescence; Macrophage Activation; Materials Testing/*methods; Mice; Models, Animal; Peptide Hydrolases/metabolism; Phagocytes

BACKGROUND: Many materials are unsuitable for medical use because of poor biocompatibility. Recently, advances in the high throughput synthesis of biomaterials has significantly increased the number of potential biomaterials, however current biocompatibility analysis methods are slow and require histological analysis. METHODOLOGY/PRINCIPAL FINDINGS: Here we develop rapid, non-invasive methods for in vivo quantification of the inflammatory response to implanted biomaterials. Materials were placed subcutaneously in an array format and monitored for host responses as per ISO 10993-6: 2001. Host cell activity in response to these materials was imaged kinetically, in vivo using fluorescent whole animal imaging. Data captured using whole animal imaging displayed similar temporal trends in cellular recruitment of phagocytes to the biomaterials compared to histological analysis. CONCLUSIONS/SIGNIFICANCE: Histological analysis similarity validates this technique as a novel, rapid approach for screening biocompatibility of implanted materials. Through this technique there exists the possibility to rapidly screen large libraries of polymers in vivo.

Journal Article

IVIS, Xen29, Xen 29, Staphylococcus aureus Xen29, Animals; Anti-Bacterial Agents/*therapeutic use; Arthroplasty/*adverse effects; Disease Models, Animal; Humans; Joint Diseases/drug therapy/*microbiology/surgery; Joints/microbiology/surgery; Male; Mice; Mice, Inbred C57BL; Minocycline/therapeutic use; Postoperative Complications/drug therapy/microbiology/*prevention &; control; Prostheses and Implants; Rifampin/therapeutic use; Staphylococcal Infections/drug therapy/microbiology/*prevention &; control/surgery; Staphylococcus aureus/drug effects/genetics/*physiology

BACKGROUND: Post-arthroplasty infections represent a devastating complication of total joint replacement surgery, resulting in multiple reoperations, prolonged antibiotic use, extended disability and worse clinical outcomes. As the number of arthroplasties in the U.S. will exceed 3.8 million surgeries per year by 2030, the number of post-arthroplasty infections is projected to increase to over 266,000 infections annually. The treatment of these infections will exhaust healthcare resources and dramatically increase medical costs. METHODOLOGY/PRINCIPAL FINDINGS: To evaluate novel preventative therapeutic strategies against post-arthroplasty infections, a mouse model was developed in which a bioluminescent Staphylococcus aureus strain was inoculated into a knee joint containing an orthopaedic implant and advanced in vivo imaging was used to measure the bacterial burden in real-time. Mice inoculated with 5x10(3) and 5x10(4) CFUs developed increased bacterial counts with marked swelling of the affected leg, consistent with an acute joint infection. In contrast, mice inoculated with 5x10(2) CFUs developed a low-grade infection, resembling a more chronic infection. Ex vivo bacterial counts highly correlated with in vivo bioluminescence signals and EGFP-neutrophil fluorescence of LysEGFP mice was used to measure the infection-induced inflammation. Furthermore, biofilm formation on the implants was visualized at 7 and 14 postoperative days by variable-pressure scanning electron microscopy (VP-SEM). Using this model, a minocycline/rifampin-impregnated bioresorbable polymer implant coating was effective in reducing the infection, decreasing inflammation and preventing biofilm formation. CONCLUSIONS/SIGNIFICANCE: Taken together, this mouse model may represent an alternative pre-clinical screening tool to evaluate novel in vivo therapeutic strategies before studies in larger animals and in human subjects. Furthermore, the antibiotic-polymer implant coating evaluated in this study was clinically effective, suggesting the potential for this strategy as a therapeutic intervention to combat post-arthroplasty infections.

Journal Article

Xen44, Xen 44, Proteus mirabilis, bioluminescence imaging, Animals; Fullerenes/*chemistry; Male; Mice; Mice, Inbred BALB C; Photochemotherapy/*methods; Photosensitizing Agents/*chemistry; Pseudomonas Infections/*drug therapy; Pseudomonas aeruginosa/drug effects; Wound Infection/*drug therapy

AIMS: Fullerenes are under intensive study for potential biomedical applications. We have previously reported that a C60 fullerene functionalized with three dimethylpyrrolidinium groups (BF6) is a highly active broad-spectrum antimicrobial photosensitizer in vitro when combined with white-light illumination. We asked whether this high degree of in vitro activity would translate into an in vivo therapeutic effect in two potentially lethal mouse models of infected wounds. MATERIALS & METHODS: We used stable bioluminescent bacteria and a low light imaging system to follow the progress of the infection noninvasively in real time. An excisional wound on the mouse back was contaminated with one of two bioluminescent Gram-negative species, Proteus mirabilis (2.5 x 10(7) cells) and Pseudomonas aeruginosa (5 x 10(6) cells). A solution of BF6 was placed into the wound followed by delivery of up to 180 J/cm(2) of broadband white light (400-700 nm). RESULTS: In both cases there was a light-dose-dependent reduction of bioluminescence from the wound not observed in control groups (light alone or BF6 alone). Fullerene-mediated photodynamic therapy of mice infected with P. mirabilis led to 82% survival compared with 8% survival without treatment (p < 0.001). Photodynamic therapy of mice infected with highly virulent P. aeruginosa did not lead to survival, but when photodynamic therapy was combined with a suboptimal dose of the antibiotic tobramycin (6 mg/kg for 1 day) there was a synergistic therapeutic effect with a survival of 60% compared with a survival of 20% with tobramycin alone (p < 0.01). CONCLUSION: These data suggest that cationic fullerenes have clinical potential as an antimicrobial photosensitizer for superficial infections where red light is not needed to penetrate tissue.

Journal Article

ProSense; FMT; fluorescence; tomography; proteases; lung; inflammation; in vivo imaging

Biomedical imaging has become an important tool in the study of “-omics” fields by allowing the noninvasive visualization of functional and molecular events using in vivo staining and reporter gene approaches. This capacity can go beyond the understanding of the genetic basis and phenotype of such respiratory conditions as acute bronchitis, adult respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), and asthma and investigate the development of disease and of therapeutic events longitudinally and in unperturbed environments. Herein, we show how the application of novel quantitative optical imaging methods, using transillumination and fluorescence molecular tomography (FMT), can allow visualization of pulmonary inflammation in small animals in vivo. The results confirm prior observations using a protease-sensitive probe. We discuss how this approach enables in vivo insights at the system level as to the dynamic role of proteases in respiratory pathophysiology and their potential as therapeutic targets. Overall, the proposed imaging method can be used with a significantly wider range of possible targets and applications in lung imaging.