Trastuzumab is a FDA-approved drug that has shown clinical efficacy against HER2+ breast cancers and is commonly used in combination with other chemotherapeutics. However, many patients are innately resistant to trastuzumab, or will develop resistance during treatment. Alternative treatments are needed for trastuzumab-resistant patients. Here, we investigate gold nanoparticle-mediated photothermal therapies as a potential alternative treatment for chemotherapy-resistant cancers. Gold nanoshell photothermal therapy destroys the tumor cells using heat, a physical mechanism, which is able to overcome the cellular adaptations that bestow trastuzumab resistance. By adding anti-HER2 to the gold surface of the nanoshells as a targeting modality, we increase the specificity of the nanoshells for HER2+ breast cancer. Silica-gold nanoshells conjugated with anti-HER2 were incubated with both trastuzumab-sensitive and trastuzumab-resistant breast cancer cells. Nanoshell binding was confirmed using two-photon laser scanning microscopy, and the cells were then ablated using a near-infrared laser. We demonstrate the successful targeting and ablation of trastuzumab-resistant cells using anti-HER2-conjugated silica-gold nanoshells and a near-infrared laser. This study suggests potential for applying gold nanoshell-mediated therapy to trastuzumab-resistant breast cancers in vivo.

Phosgene (CG) is a highly irritant gas widely used industrially as a chemical intermediate for the production of dyes, pesticides, and plastics, and can cause life-threatening pulmonar y edema within 24 hours of exposure. This study was designed to investigate acute changes in lung tissue histopathology and selected bronchoalveola r lavage uid (BALF) factors over time to determine early diagnostic indicators of exposure. Three groups of 40 male mice each were exposed to 32 mg/m 3 (8 ppm) CG for 20 minutes, and 3 groups of 40 control male mice were exposed to ltered room air for 20 minutes, both exposures were followed by room air washout for 5 minutes. At 1,4,8,12,24, 48, and 72 hours after exposure each group of mice was euthanized and processed for histopatholog y, bronchoalveola r lavage or gravimetric measurements , respectively. Over time, the histopathologica l lesions were characterized by acute changes consisting of alveolar and interstitial edema, brin and hemorrhage , followed by signi cant alveolar and interstitial ooding with in ammatory cell in ltrates and scattered bronchiolar and terminal airway epithelial degeneratio n and necrosis. From 48 to 72 hours, there was partial resolution of the edema and degenerative changes, followed by epithelial and broblastic regeneration centered on the terminal bronchiolar areas. Bronchoalveola r lavage was processed for cell differential counts, LDH, and protein determination. Comparative analysis revealed signi cant increases in both postexposur e lung wet/dry weight ratios, and early elevations of BALF LDH and protein, and later elevations in leukocytes. This article describes the use of histopathology to chronicle the temporal pulmonary changes subsequent to whole body exposure to phosgene , and correlate these changes with BALF ingredients and postexposur e lung wet weights in an effort to characterize toxic gas-induced acute lung injury and identify early markers of phosgene exposure.

Detection of acute lung injury is important if therapeutic medical countermeasures are to be used to reduce toxicity in a timely manner. Indicators of injury may aid in the eventual treatment course and enhance the odds of a positive outcome following a toxic exposure. This study was designed to investigate the effects of a toxic exposure to the industrial irritant gas phosgene on the electrolyte levels in arterial blood and bronchoalveolar lavage fluid (BALF). Phosgene is a well-known chemical intermediate capable of producing life-threatening pulmonary edema within hours after exposure. Four groups of 40 Crl:CD-1(ICR)BR male mice were exposed whole-body to either air or phosgene at a concentration x time (c x t) amount of 32-42 mg/m(3) (8-11 ppm) phosgene for 20 min (640-840 mg x min/m(3)). BALF from air- or phosgene-exposed mice was taken at 1, 4, 8, 12, 24, 48, or 72 h postexposure. After euthanasia, the trachea was excised, and 800 microl saline was instilled into the lungs. The lungs were washed 5x. Eighty microliters of BALF was placed in a cartridge and inserted into a clinical i-STAT analyzer. Na(+), Cl(-), K(+), and ionized Ca(2+) were analyzed. Arterial blood electrolyte levels were also analyzed in four additional groups of air- or phosgene-exposed mice. The left lung was removed to determine wet weight (WW), an indicator of pulmonary edema. Na(+) was significantly higher in air than in phosgene-exposed mice at 4, 8, and 12 h postexposure. Temporal changes in BALF Cl(-) in phosgene mice were not statistically different from those in the air mice. Both Ca(2+) and K(+) were significantly higher than in the air-exposed mice over 72 h, p < or = 0.03 and p < or = 0.001 (two-way analysis of variance, ANOVA), respectively. Significant changes in BALF K(+) and Ca(2+) occurred as early as 4 h postexposure in phosgene, p < or = 0.005, versus air-exposed mice. Over time, there were no significant changes in arterial blood levels of Na(+), Cl(-), or Ca(2+) for animals exposed to air versus phosgene. However, arterial K(+) concentrations were significantly higher, p < or = 0.05, than in air-exposed mice across all time points, with the highest K(+) levels of 7 mmol/L occurring at 8 h and 24 h after exposure. Phosgene caused a time-dependent significant increase in WW from 4 to 12 h, p < or = 0.025, compared with air-exposed mice. These data demonstrate that measuring blood K(+) levels 1 h after exposure along with BALF Na(+), K(+), and Ca(2+) may serve as an alternate indicators of lung injury since both K(+) and Ca(2+) follow temporal increases in air-blood barrier permeability as measured by wet weight.