Carlo Montemagno

Biomolecular motors such as F 1 –adenosine triphosphate synthase (F 1 -ATPase) and myosin are similar in size, and they generate forces compatible with currently producible nanoengineered structures. We have engineered individual biomolecular motors and nanoscale inorganic systems, and we describe their integration in a hybrid nanomechanical device powered by a biomolecular motor. The device consisted of three components: an engineered substrate, an F 1 -ATPase biomolecular motor, and fabricated nanopropellers. Rotation of the nanopropeller was initiated with 2 mM adenosine triphosphate and inhibited by sodium azide.

BACKGROUND: Since morbidity and mortality rates due to oral cavity and oropharyngeal squamous cell carcinoma (OSCC) have improved little in the past 30 years, early detection or prevention of this disease is likely to be most effective. Using laser-capture microdissection, we have identified the expression of 2 cellular genes that are uniquely associated with OSCC: interleukin (IL) 6 and IL-8. These cytokines may contribute to the pathogenesis of this disease, and have been linked with increased tumor growth and metastasis. OBJECTIVES: To investigate whether IL-6 and/or IL-8 could serve as informative biomarkers for OSCC in saliva and/or serum and to determine if there is a role for saliva as a diagnostic medium for OSCC. PATIENTS AND METHODS: Patients with newly diagnosed T1 or T2 oral cavity or oropharyngeal histologically confirmed squamous cell carcinoma were recruited for the study. Age and sex-matched disease-free subjects were used as controls. Using quantitative real-time polymerase chain reaction analysis and enzyme-linked immunosorbent assay, we respectively assessed the expression of IL-6 and IL-8 in serum (controls, n = 32; patients with OSCC, n = 19) and saliva (controls, n = 32; patients with OSCC, n = 32) at the messenger RNA (mRNA) and protein levels. MAIN OUTCOME MEASURES: Specificity and sensitivity of these biomarkers for OSCC and their predictive value. RESULTS: Interleukin 8 was detected at higher concentrations in saliva (P<.01) and IL-6 was detected at higher concentrations in serum of patients with OSCC (P<.01). We confirmed these results at both the mRNA and the protein levels, and the results were concordant. The concentration of IL-8 in saliva and IL-6 in serum did not appear to be associated with sex, age, or alcohol or tobacco use (P>.75). Using statistical analysis, we were able to determine the threshold value, sensitivity, and specificity of each biomarker, as well as a combination of biomarkers, for detecting OSCC. CONCLUSIONS: Our findings indicate that IL-8 in saliva and IL-6 in serum hold promise as biomarkers for OSCC. A saliva-based test could be a cost-effective adjunctive tool in the diagnosis and follow-up of patients with OSCC.

A complex cellular process was reconstructed using a multiprotein polymersome system. ATP has been produced by coupled reactions between bacteriorhodopsin, a light-driven transmembrane proton pump, and F(0)F(1)-ATP synthase motor protein, reconstituted in polymersomes. This indicates that ATP synthase maintained its ATP synthesis and therefore its motor activity in the artificial membranes. This hybrid proteopolymersome will have wide application in a number of fields ranging from the in vitro investigation of cellular metabolism to the synthesis of functional "smart" materials.

A confluence in scientific advancements associated with molecular biology and nanofabrication technology now offers the potential of engineering functional hybrid organic/inorganic nanomechanical systems. Our objectives were to: (i) establish a system for producing a recombinant biomolecular motor; (ii) precisely position and orient biological molecules on nanofabricated substrates; and (iii) acquire baseline performance data on a biomolecular motor in a hybrid system. A recombinant expression system was established for the large-scale production of a thermostable biomolecular motor, F1-ATPase, modified to contain chemically active `handles.' His tags were used to specifically attach, as well as precisely position and orient, biological molecules on nickel, copper and gold substrates created using electron beam lithography. Further, these substrates were used to attach F1-ATPase and acquire baseline performance data on motor rotation through the attachment of fluorescent microspheres to the tip of the γ subunit. Counterclockwise rotation of the γ subunit was measured at approximately 10 Hz (3-4 rev s-1) using a differential interferometer. These data have established several prerequisite technologies that are essential to the integration of biomolecular motors in nano-electro-mechanical systems. The evolution of these technologies will open the door to the seamless integration of the motive power of life with engineered nanofabricated devices.