R. Dutour1, A.T. Nguyen2, I. Jabin3, I. Demeestere2 and G. Bruylants1
1 Engineering of Molecular Nanosystems (EMNS), Université Libre de Bruxelles (ULB)
2 Laboratory of Human Reproduction, ULB
3 Laboratoire de Chimie Organique, ULB
Contact : Raphael.Dutour@ulb.be
Cancer treatments, such as cyclophosphamide, are known to cause several side effects, like follicle apoptosis, and thus increase the risk of infertility. A previous study has identified the miRNA let-7A to be strongly downregulated in mouse ovaries following chemotherapy, and this latter seems to play a key role towards apoptosis1. Our objective is to develop an ovarian selective Delivery System based on gold nanoparticles (AuNPs) for this miRNA with the aim to restore a normal activity level of let-7a. Nucleic acids are usually attached to AuNPs using thiol chemistry (AuNPs-S-NA); however, this strategy presents some limitations such as the robustness of the organic layer and the lack of control over the nucleic acid loading. We worked on the development of AuNPs functionalized with calixarenes, macrocyclic molecules that allows the formation of a robust layer on the NPs through multiple carbon-gold bonds, and different possibilities of subsequent bioconjugation2,3. To date, we have notably developed AuNPs functionalized with calixarenes bearing PEG chains to promote biocompatibility, but also functional groups allowing the covalent attachment of DNA-RNA strands with a controlled density. Some promising results were obtained with this new bioconjugation nanoplatform. Using mixtures of calixarenes bearing different functional groups, orthogonal bioconjugation of two different biological molecules can be envisaged, opening the possibility to add a targeting ligand as an antibody4. Some interesting preliminary results about the location of the AuNPs-RNA in cells were obtained, using particles loaded with a fluorescent RNA strand. The comparison of the efficiency of AuNPs-calixarenes-miRNAs to that of AuNPs-S-miRNAs for nucleic acids delivery is currently under investigation. Cellular uptake of AuNPs and miRNA delivery were observed with both systems, and we are confident that the AuNPs-calixarenes-miRNAs could constitute an efficient and controllable system for nucleic acids delivery, and thus could be applied to several therapeutic strategies.
References
1. Alexandri, C., Stamatopoulos, B., Rothé, F., Bareche, Y., Devos, M., Demeestere, I., Scientific Reports 2019, 9, 9636-9646.
2. Valkenier, H., Malytskyi, V., Blond, P., Retout, M., Mattiuzzi, A., Goole, J., Raussens, V., Jabin, I., Bruylants, G., Langmuir 2017, 33, 8253-8259.
3. Retout, M., Blond, P., Jabin, I., Bruylants, G., Bioconjugate Chemistry 2021, 32, 290-300.
4. Retout, M., Cornelio, B., Bruylants, G., Jabin, I., Langmuir 2022, 38, 9301-9309.