Gold nanoclusters (GNC) exhibit interesting potential as biocompatible tools for nanomedical applications in both imaging diagnosis and therapies due to their fluorescent properties, stability, and low toxicity. In the absence of radiation, BSA-capped gold nanoclusters do not cause toxicity in vitro. Also, their toxic effect on an in vivo model as Zebrafish was determined. Danio rerio is a versatile intermediate model, useful for toxicity evaluation of nanomaterials in general.
Methods
Toxicity in Zebrafish. Larvae were placed on 96-well plate at 1 day post fecundation (dpf), three individuals per well, and maintained at 28 ± 1°C with a cycle of 14/10 h of light/dark in E3 medium (NaCl 0.29 g/l, KCl 0.012 g/l, CaCl2 0.036 g/l and MgSO4 0.039 g/l and 50ppb methylene blue in deionized water). At 5 dpf BSA-capped GNC were added. The spontaneous movement was measured during 15 min, at 1, 24, and 48 h post-incubation (hpi) with a WMicrotracker device at room temperature. Results were relativized to the untreated control and reported as the percent of swimming activity.
Results
Zebrafish larvae did not die after the experiments at the tested doses. The spontaneous movement was significantly diminished when incubated with BSA-capped GNC at a concentration of 60μM, for all incubation times (Fig. 11). At the highest tested concentration -120μM, no significant alterations in swimming respect to the control were observed, probably due to aggregation of the clusters. Another reason for the apparent recovery of the swimming activity at the highest concentration tested could be related to the protective effect addressed to BSA mentioned in the cytotoxicity determinations.
Mater Sci Eng C Mater Biol Appl. 2020 Jul;112:110891. doi: 0.1016/j.msec.2020.110891.
Lilloa CR, Caliennib MN, Aiellod BR, Prietob MJ, Sartorid DR, Tuninettid J, Toledoc P, Alonso S, Moyae S, Gonzalezd MC, Montanarib J, Soler-Illiaa G.