Anales RANF

Juan Aparicio Blanco, Ignacio A. Romero, Jean P Benoit, Ana I. Torres Suárez @Real Academia Nacional de Farmacia. Spain 210 The results from cell viability experiments are shown in Figure 9. Noticeably, none of the formulations of blank LNCs utilized as controls showed significant cytotoxicity against the U373MG cell line within the evaluated concentration range according to ISO 10993-5 (Biological evaluation of medical devices, Part 5: Tests for in vitro cytotoxicity). Therefore, all changes in the percentage of cell viability following treatment with CBD-loaded LNCs can be attributed to the extent of CBD released from the LNCs at each time point. Figure 9: Cytotoxicity of blank LNCs and CBD-loaded LNCs in different sizes against the human glioblastoma U373MG cell line. (a) Cytotoxicity of 20 nm-sized blank LNCs after 48 (orange) and 96 hours (red). (b) Cytotoxicity of 40 nm-sized blank LNCs after 48 (orange) and 96 hours (red). (c) Cytotoxicity of 20 nm-sized CBD-loaded LNCs after 48 (pistachio) and 96 hours (dark green). (d) Cytotoxicity of 40 nm-sized blank LNCs after 48 (pistachio) and 96 hours (dark green). Free CBD showed a clear antiproliferative effect against the glioblastoma cells (IC 50 = 29.1 µM, Figure S3). The encapsulation of CBD considerably increased this IC 50 value, as free CBD is readily available, whereas encapsulated CBD must be first released from the oily core of LNCs to exert its cytotoxic effect on glioma cells. Similar trends have been described for other drug-loaded carriers (56, 62, 63). The size of LNCs played a key role in the extent of CBD release and subsequent cytotoxicity: the smaller- sized CBD-loaded LNCs reduced by 3.0-fold the IC 50 value achieved with the bigger-sized CBD-loaded LNCs both after 48 (202.6 µM versus 615.4 µM) and 96 hours (129.1 µM versus 375.4 µM). Moreover, as deduced from the reduction in the IC 50 values from 48 to 96 hours, LNCs continued to release CBD. Accordingly, CBD-loaded LNCs act as efficient extended-release carriers with great potential for glioma therapy. 4. CONCLUSIONS The results presented herein serve to envision LNCs, prepared by the PIT method and loaded with CBD in their oily core and functionalized with CBD on their surface, as promising dually-targeted candidates for intravenous treatment of glioma. We have introduced, on the one hand, a pioneering functionalization strategy for brain tumor targeting of LNCs with this non-immunogenic and non- psychotropic cannabinoid (with better targeting properties than some other targeting strategies that have already reached the clinical trials stage) and, on the other hand, nanocapsules as extended-release carriers of CBD at high drug loading to overcome the formulation issues usually associated with cannabinoids that have heretofore constrained their therapeutic potential. Moreover, to contribute to the rational design of nanocapsules, we have demonstrated that both the BBB and glioma targeting ability and the drug release rate can be tailored by varying