Graphitic nanomaterials such as graphene layers (G) and single-wall carbon nanotubes (SWCNT) are potential candidates in a large number of biomedical applications. However, little is known about the effects of these nanomaterials on biological systems. Here we show that the shape of these materials is directly related to their induced cellular toxicity. Both G and SWCNT induce cytotoxic effects, and these effects are concentration- and shape-dependent. Interestingly, at low concentrations, G induced stronger metabolic activity than SWCNT, a trend that reversed at higher concentrations. Lactate dehydrogenase levels were found to be significantly higher for SWCNT as compared to the G samples. Moreover, reactive oxygen species were generated in a concentration- and time-dependent manner after exposure to G, indicating an oxidative stress mechanism. Furthermore, time-dependent caspase 3 activation after exposure to G (10 microg/mL) shows evidence of apoptosis. Altogether these studies suggest different biological activities of the graphitic nanomaterials, with the shape playing a primary role.

Purpose To present pilot toxicity and survival outcomes for a prospective trial investigating adaptive radiotherapy (ART) for oropharyngeal squamous cell carcinoma. Methods Twenty-four patients enrolled onto an IRB-approved clinical trial. Twenty-two patients were analyzed. Daily CT-guided setup and deformable image registration permitted serial mapping of CTVs and avoidance structures for ART planning. Primary site was base of tongue in 15 patients, tonsil in 6, and glossopharyngeal sulcus in 1. Twenty (91%) patients had AJCC stage IV disease. T stage distribution was 2 T1, 12 T2, 3 T3, 5 T4 and N stage distribution was 1 N0, 2 N1, 5 N2a, 12 N2b, and 2 N2c. Twenty-one (95%) patients received systemic therapy. Results With 31 month median follow up (range: 13-45), there has been no primary site failure and 1 nodal relapse, yielding 100% local and 95% regional disease control at 2 years. Baseline tumor size correlated with absolute volumetric treatment response (p = 0.018). Parotid volumetric change correlated with duration of feeding tube placement (p = 0.025). Acute toxicity was comparable to conventional IMRT results. Chronic toxicity and functional outcomes beyond 1 year were tabulated. Discussion This is the first prospective evaluation of morbidity and survival outcomes in patients with locally advanced head and neck cancer treated with automated adaptive replanning. ART can provide dosimetric benefit with only 1 or 2 mid-treatment replanning events. Our preliminary clinical outcomes document functional recovery and preservation of disease control at one-year follow-up and beyond.

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Fluorescent probes, as noninvasive tools for visualizing the metabolism of biomolecules, hold great potential to explore their physiological and pathological processes. For cysteine (Cys), however, none of the reported fluorescent probes could image the metabolic processes in living cells. To achieve this goal, we developed a coumarin derivative based on rational design of the dual recognition sites for Cys and its metabolite, SO. The probe displayed distinct two channels with turn-on fluorescent emission toward Cys and SO, which were successfully applied for imaging both A549 cells and zebrafish. Further, with reversible fluorescent responses toward Cys, the probe could image the enzymatic conversion of Cys to SO in living A549 cells in a ratiometric manner. The present work reports the first probe to image the endogenous generated SO without incubation of the SO donors.

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