In this project, we fabricated lipid-based nanocapsules made of synthetic (e.g. cetyl palmitate) and natural lipids (e.g. sphingomyelin, total brain lipid extract) able to encapsulate a combination of antioxidants, including nanoceria particles (ROS scavengers) and LNIL (a specific inhibitor of the nitric oxide synthesis). To facilitate the delivery of the nanocapsules into the brain, we attached to their surface specific targeting groups (e.g. T7 and angiopep-2 peptides) that could connect to the endothelial cells of the BBB and improve their crossing to the damaged tissue. The first developed system was comprised of cetyl palmitate nanocapsules encapsulating nanoceria (NC-NLCs). Our published data showed that the antioxidant properties of nanoceria were not affected by their encapsulation, suggesting that the system as a whole could act as an antioxidant therapeutic. Further studies showed that these nanocapsules were able to cross an in vitro model of BBB that we fabricated in the lab. In this study, it was also demonstrated that the nanocapsules could protect neuron-like cells undergoing oxidative stress (treatment with an excess of H2O2, which is the most abundant ROS) from dying. Additionally, it was shown that the treatment of these cells with the antioxidant nanocapsules led to an increased number and length of neurites suggesting neurogenic properties.
Based on these results and aiming at making our system more biomimetic, I proceeded in the fabrication of nanocapsules made from commercially available lipids extracted from a porcine brain. The brain lipids were used as a lipid-matrix able to encapsulate nanoceria and the aforementioned specific inhibitor LNIL (LNIL-Ce-BL). This time we attached on the surface of the fabricated LNIL-Ce-BL nanocapsules two different peptides, and we studied if they facilitate their uptake by the cells of the BBB and the neuronal cells. From the tested peptides, only the so-called T7 and angiopep-2 peptides showed to improve the internalization of the nanocapsules. The antioxidant ability was also tested, and it was found that BIONICS (LNIL-Ce-BL-T7) (Figure 1) act better than free nanoceria or LNIL acting by themselves. The in vitro preliminary data (experiments with cells) presented an enhanced therapeutic effect of BIONICS, compared to the control untreated cells or cells treated only with nanoceria or LNIL. It has to be noted that the therapeutic effect of BIONICS against oxidative stress, as well as the level of neuroprotection that BIONICS can offer, was assessed under a modified ischemia/reperfusion model reported in another study. The data showed that BIONICS could reduce oxidative stress derived from overproduced reactive oxygen and nitrogen species, and can protect both the endothelial cells of the BBB as well as the neuron-like cells from dying.
Although additional and more extensive studies are needed, the results derived from this project suggest the potential use of a lipid-based antioxidant treatment as adjuvant therapy for the amelioration of post-ischemia effects.
EXPLOITATION
During this project, a novel idea, on the development of a biomimetic delivery system acting as a versatile theranostic, was generated and is under review for its patentability.
DISSEMINATION
The results of the project were disseminated through a series of conferences (ESB 2019, Nanotoday 2019, EMRS 2018, ESB 2018) and publications (ACS Biom. Sci. & Eng., DOI: 10.1021/acsbiomaterials.8b01033 Adv. Funct. Mater., DOI: 10.1002/adfm.201906283 J. Mater. Chem. B., DOI: 10.1039/D0TB00260G.
Furthermore, a short video-animation in which the causes of ischemic stroke and how BIONICs can help, was created for the non-scientific audience. The video was uploaded in the BIONICs' webpage, as well as in Youtube (
https://www.youtube.com/watch?v=PmPU1On_hbs(s’ouvre dans une nouvelle fenêtre)) under the name 'Cell Wars-Ischemic Stroke: A New Hope (With Subtitles)'
