The preparation, characterization, and preliminary biomedical application of various nitric oxide (NO)-releasing fumed silica particles (0.2-0.3 microm) are reported. The tiny NO-releasing particles are synthesized by first tethering alkylamines onto the surface of the silica using amine-containing silylation reagents. These amine groups are then converted to corresponding N-diazeniumdiolate groups via reaction with NO(g) at high pressure in the presence of methoxide bases (e.g., NaOMe). N-Diazeniumdiolate groups were found to form more readily with secondary amino nitrogens than primary amino nitrogens tethered to the silica. Different alkali metal cations of the methoxide bases, however, have little effect on the degree of N-diazeniumdiolate formation. The N-diazeniumdiolate moieties attached on the silica surface undergo a primarily proton-driven dissociation to NO under physiological conditions, with an "apparent" reaction order somewhat greater than 1 owing to local increases in pH at the surface of the particles as free amine groups are generated. The rates of N-diazeniumdiolate dissociation are further related to the parent amine structures and the pH of the soaking buffer. The N-diazeniumdiolate groups also undergo slow thermal dissociation to NO, with zero-order dissociation observed at both -15 and 23 degrees C. It is further shown that the resulting NO-releasing fumed silica particles can be embedded into polymer films to create coatings that are thromboresistant, via the release of NO at fluxes that mimic healthy endothelial cells (EC). For example a polyurethane coating containing 20 wt % of NO-releasing particles prepared with pendant hexane diamine structure (i.e., Sil-2N[6]-N(2)O(2)Na) is shown to exhibit improved surface thromboresistivity (compared to controls) when used to coat the inner walls of extracorporeal circuits (ECC) employed in a rabbit model for extracorporeal blood circulation.

Background and Objective Basal cell carcinomas (BCCs) have supporting vasculature that serves as a target for vascular selective lasers. The objective of this study was to determine the effect of repeated treatment with a combined 585 nm pulsed dye laser (PDL) and 1,064 nm Neodymium Yttrium Aluminum Garnet (Nd:YAG) laser on BCCs of superficial and nodular subtypes of varying diameters. Study Design/Materials and Methods Ten subjects with 13 biopsy‐proven BCCs received four combined PDL and Nd:YAG at treatments 2–4 week intervals. None of the BCCs met the criteria for Mohs micrographic surgery. The tumor and 4 mm of peripheral skin were treated using standardized parameters delivered with a 7 mm spot with 10% overlap. The treated area was excised and evaluated histologically for residual tumor. The primary study endpoint was histologic clearance of tumor. The secondary study endpoint was blinded investigator assessment of clinical endpoint and adverse effects. Results Approximately half of all tumors showed a complete response to four combined PDL and Nd:YAG treatments (n = 7/12, 58%). When stratified by size, 75% of all tumors <1 cm in diameter (n = 6/8) showed complete response. Tumor histologic types among the complete responders included superficial and nodular BCCs. All subjects with incompletely responding BCCs were on various forms of anticoagulation, which we hypothesize, may inhibit laser‐mediated thrombosis necessary for the clinical effect. Blinded investigator assessment suggests that biopsy related erythema improves with subsequent laser treatments. Conclusions Combined PDL and Nd:YAG laser is an effective means of reducing tumor burden in patients with BCC and may be a promising, emerging alternative therapy. Factors influencing treatment response includes the concomitant use of anticoagulation. Further studies are needed to investigate and optimize the utility of this treatment protocol. Lasers Surg. Med. 46:1–7, 2014. © 2013 Wiley Periodicals, Inc.

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Solar lentigines are considered one of the earliest signs of photoaging and are an extremely common cosmetic complaint. Successful removal of these lesions can be achieved with laser and non-laser light sources, and is one of the most frequently performed cosmetic procedures in laser centers. Distinguishing a benign lentigo from other pigmented lesions can sometimes be challenging, even for a trained dermatologist. We report a series of three patients who presented to our laser center within 2 months of one another for cosmetic removal of pigmented lesions that were found to be melanoma. One patient was referred by another dermatologist, one by a physician family member, and the other presented on his own. These cases highlight the need for careful evaluation of pigmented lesions prior to laser treatment, regardless of the source of the referral. In this article, we will review the diagnostic and treatment differences between lentigines and their malignant counterparts, and examine the role of laser in both.

sample of patients treated by the senior authors (C.H.M. and G.M.) because photographs are not consistently obtained at the 72-hour to 96-hour follow-up appointment. In addition, 2 of the patients in the RFMN-alone treatment group were on medications that impair coagulation. The results were still statistically significant after excluding these 2 patients from the data analysis. Figure 1 (left) demonstrates the typical bruising pattern for an unlayered, nonmedicated perioral RFMN treatment. The authors suspect dermal microcirculation tamponade as a possible mechanism for bruising reduction in this layered treatment approach, a hypothesis that could be confirmed histologically in future studies.

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