Bare plasmonic metal nanoparticles: synthesis, characterisation and in vitro toxicity assessment on a liver carcinoma cell line.

Metal nanoparticles have generated great interest due to their excellent optical and chemical properties. The widely used chemical method for synthesising nanoparticles involves capping agents for colloidal stability. However, there are scarce reports on the application of metal nanoparticles synthesised without using capping agents. Hence, there is a need to develop pristine nanoparticles devoid of capping that can be used for translational research. Here, the authors developed a facile and rapid method for synthesising bare metal nanoparticles (platinum/silver/gold) that are chemically reactive and stable for a month upon storage. They synthesised bare metal nanoparticles of sub-15 nm and characterised using standard techniques (UV-VIS-NIR/DLS/zeta//TEM/XRD). They assessed the safety of the synthesised nanoparticles on the liver carcinoma cell line (HepG2). Bare gold and platinum nanoparticles were non-toxic in comparison to bare silver nanoparticles. Bare metal nanoparticles were also checked for metal detection wherein antimony, mercury and chromium were detected using bare gold and silver nanoparticles. The spectroscopic shifts of the nanoparticles when bound to metals resulted in blue and red shifting of the plasmon band, indicating the sensing of metals. These results show that bare metal nanoparticles have the potential to emerge as a promising candidate for biomedical and sensing applications.

Assessment of sublethal endpoints after chronic exposure of the nematode Caenorhabditis elegans to palladium, platinum and rhodium.

The aim of this study was to investigate chronic effects of the platinum-group elements (PGE) palladium (Pd), platinum (Pt) and rhodium (Rh) on the nematode Caenorhabditis elegans. Aquatic toxicity testing was carried out according to ISO 10872 by determining 96 h EC50 values for sublethal endpoints, including growth, fertility and reproduction. Single PGE standard solutions were used as metal source. Based on the EC50 values for Pt, reproduction (96 h EC50 = 497 µg/L) was the most sensitive endpoint followed by fertility (96 h EC50 = 726 µg/L) and growth (96 h EC50 = 808 µg/L). For Pd, no precise EC50 values could be calculated due to bell-shaped concentration response curves, but the 96 h EC50 for reproduction ranged between 10 and 100 µg/L. Pd and Pt had effects on all endpoints. With raising element concentrations reproduction was inhibited first. At a certain concentration, fertility was also affected, which in turn had an additional effect on reproduction. Growth inhibition can also lead to a loss of fertility if the worms do not reach an appropriate body size to become fertile. Rhodium showed no inhibition of any endpoint between concentrations of 100 to 10,000 µg Rh/L. The results of this study allow the following order of PGE with respect to decreasing toxicity to C. elegans: Pd > Pt ¼ Rh.

Cutting costs and standardizing care: Once-per-cycle complete blood count monitoring may be safe for patients undergoing platinum-based chemotherapy.

AIM: The aim of this study was to evaluate whether frequency of complete blood count (CBC) testing during chemotherapy for gynecologic cancer impacts hospital admissions or rates of neutropenic fever. METHODS: A retrospective cohort study was performed at a single academic institution. Patients undergoing platinum-based chemotherapy for endometrial or ovarian cancer from January 2010 to December 2014 were identified from a clinical database. Patients receiving dose-dense chemotherapy or on a clinical trial were excluded. Electronic chart review collected demographic and clinical characteristics. The primary outcome was the rate of febrile neutropenia or hospital admission. RESULTS: A total of 174 patients were identified, 63 (36%) with endometrial and 111 (64%) with ovarian cancer. Fifty-four percent of patients received multiple CBC per cycle compared with 46% who only had one CBC per cycle. The majority of patients were treated with a platinum-based doublet (85%). Dose reductions, addition of granulocyte colony stimulating factor, and rates of grade 3 or 4 anemia and neutropenia were significantly associated with more frequent testing. There was no difference in rates of neutropenic fever (5.3 vs 3.8%, P = 0.45) or hospital admission (22.3 vs 21.3%, P = 0.86) for multiple versus single CBC monitoring. CONCLUSION: More frequent laboratory testing detected more cases of grade 3 or 4 hematopoietic toxicities and was associated with more interventions. There were no differences in number of hospitalizations or cases of neutropenic fever by frequency of laboratory testing, suggesting that it may be appropriate to decrease routine laboratory tests for select patients.

In-vitro thrombogenicity assessment of polymer filament modified and native platinum embolic coils.

BACKGROUND: Embolic coils have been used to treat intracranial aneurysms using an endovascular approach for more than two decades. However, significant aneurysm recanalization rates have been reported specifically in large and giant aneurysms. Adding filaments to bare Platinum coils is considered a modification and has been proposed to achieve higher aneurysm occlusion rates as compared to bare Platinum coils. Quantitative information - in terms of thrombin generation potential of these modifications - is however lacking. OBJECTIVE: We report here in vitro thrombogenicity of Platinum coils containing Nylon (Axium™ MicroFx™ Nylon coil) and PGLA (Axium™ MicroFx™ PGLA coil) filaments and compare them with equivalent bare Platinum Axium™ coils. METHOD: We utilize a quantitative method that tracks the formation of thrombin upon exposure of the test samples to human platelet rich plasma using a slow binding fluorogenic substrate. RESULTS: We report a significant increase in the total thrombin turnover, the peak thrombin amount and the rate of thrombin generation for the Axium™ MicroFx™ coils and filaments compared to the Axium™ coils and Platinum wire. CONCLUSION: Nylon and PGLA filaments added to bare Platinum coils increase thrombogenicity of coils. This study offers a robust quantitative method to compare thrombus formation efficacy of embolic coils under static conditions.

Concerns for asthma at pre-placement assessment and health surveillance in platinum refining--a personal approach.

Platinum, a noble metal, is inert in the body and has an important use in medical applications. It is used in autocatalysts to control harmful vehicular emissions and the catalytic effects improve efficiencies of pharmaceutical and petrochemical processes. The refining process involves exposure to halogeno complex salts of platinum which are potent allergens. They induce symptoms typical of a type I allergy, the most significant of which is asthma. Platinum refining not only exposes employees to the risk of sensitization to these salts but also to respiratory irritants. Inhalation of these aggravates pre-existing asthma. The increasing incidence of asthma in the community requires that prospective employees for platinum refining be assessed carefully to establish their respiratory health status in relation to the risk of sensitization or aggravation of pre-existing asthma. Routine medical surveillance has been shown to reduce persistence of asthma in sensitized workers who cease exposure to the platinum salts upon diagnosis. Skin prick test using dilute platinum salt solutions can detect sensitization at an early stage and this has become the mainstay of surveillance programmes as it is objective and reproducible as well as predictive for the development of symptoms when exposure is allowed to continue. Symptoms are not sensitive or specific. Smoking is a significant risk factor.