Periodic Reporting for period 1 - HyHeat (Profiling gene expression in Hydra vulgaris following Gold Nanoparticle-mediated hyperthermia)
Reporting period: 2015-09-01 to 2017-08-31
While significant efforts have been made to develop suitable NPs with appropriate heating capabilities, to date, the molecular mechanisms underlying the in vivo cellular responses to heat stress remain unclear.
Therefore, the overall aim of the HyHeat project is to use an invertebrate model (Hydra vulgaris) to screen the heating capabilities of different AuNPs in vivo, with the grand aim of understanding the cellular responses to heat stress and therefore taking the first steps towards improving nanoparticle mediated HT efficacy for therapeutic purposes. A simple invertebrate organism have been used, in line with European strategies aimed to reduce vertebrate experimentation. During the project, we have synthesized different types of AuNPs and fully characterized them. The toxicity in the animals have been assessed using different techniques, before proceeding to laser irradiation. Lastly, gene expression profiling after laser irradiation in Hydra has been performed. It has been possible to characterize the heating capabilities of the AuNPs in vivo and select deregulated genes upon irradiation.
Both types of AuNPs have been incubated with Hydra to test the toxicity in adult animals, using different assays, namely alterations in the morphology of the animals, in the regeneration rates or the reproduction processes. To study the biodistribution of the nanoparticles, fluorescence microscopy, TEM and ICP have been used.
Laser irradiation conditions were tuned to obtain a mild and sublethal hyperthermia treatment. For measuring the modulation of the genes upon laser irradiation, qRT-PCR was performed. Cell necrosis and viability were also evaluated using DAPI and propidium iodide staining. After the molecular analysis we have been able to classify the AuNP heating capabilities in vivo and to identify the genes that are deregulated upon laser irradiation. In mice, it has been shown that AuNPs are not toxic either at short or long term, which is a good point for the design of future PTT experiments.
The main results of the project have been disseminated using different channels depending on the target audience. In a scientific context, one manuscript have been published, and three are being prepared or under review. The results have been presented in four scientific conferences and invited talks at different Research Institutes. Outreach activities for general public have been performed for elementary and secondary schools, as well as publishing an article in a non-scientific journal.