## 4 Conclusions  
Our findings revealed that LaDEO and CnEO were the most active among eight different EOs against both lung cancer (A549) and colon cancer (HCT-116) cells. Encapsulation of LaDEO and CnEO into SLN improved the anticancer effects of free EO in both cell lines. SLN/CnEO in A549 cells resulted in the most effective system. A deeper characterization of SLN/CnEO revealed a high EE of CnEO and an interesting pH dependency of CnEO release from SLN, favoring CnEO release in acidic conditions, which mimicked the endolysosomal compartment. SLN/CnEO seemed to be highly biocompatible since no toxic effects on red blood cells or normal lung fibroblasts were observed at concentrations at which A549 cancer cells were completely killed. In contrast to free CnEO, SLN/CnEO induced significant A549 cell death that seemed to be independent of the mitochondrial depolarization pathway and substantially enhanced the inhibition of A549 cell migration mediated by free CnEO. The obtained formulations could be considered green anticancer tools in adjuvant and/or complementary therapies. However, additional investigations focusing on molecular mechanisms and in vivo studies are recommended. This information may be useful for the development of innovative treatment modalities, including the incorporation of conventional lipophilic chemotherapeutics into SLN/EO. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/pharmaceuticals15082045/s1](https://www.mdpi.com/article/10.3390/pharmaceuticals15082045/s1)]([https://www.mdpi.com/article/10.3390/pharmaceuticals15082045/s1](https://www.mdpi.com/article/10.3390/pharmaceuticals15082045/s1)), Figure S1: (A) UV-Vis scanning of CnEO (230-270 nm). A stable and intense peak at 258 nm was observed. (B-C) Calibration curve of CnEO (0.01-0.1 \(\upmu\)L/L) in (B) 20% EtOH in PBS 10 mM (pH 7.4) or (C) 20% EtOH Ac-AcH 10 mM (pH 5.0); Figure S2: Encapsulation of CnEO increases A549 cell death. Table S1: IC50 values of eight different essential oils on A549 and HCT-116 cells. Table S1. IC50 values of eight different essential oils on A549 and HCT-116 cells. Figure 6: Encapsulation of CnEO increases the inhibition of A549 cell migration. Cell migration was analyzed by the wound healing assay. Cells were exposed to 0.1% ethanol (control), empty SLN, free CnEO, or SLN/CnEO (50 and 100 \(\upmu\)L/L) for 48 h. (**A**) Representative images were obtained at 0 and 48 h (40\(\times\)). (**B**) Quantitative analysis of wound healing closure. Data are presented as the mean \(\pm\) SD (n = 4). (a) \(p<\) 0.05 vs. Control; (b) \(p<\) 0.05 vs. equivalent concentration of free CnEO. **Author Contributions:** Conceptualization, B.R.-K., S.G., G.R.C., C.Y.C. and G.A.I. ; methodology, B.R.-K., M.A.C., R.C.G., J.G., J.S.C., C.Y.C. and G.A.I. ; validation, B.R.-K.; formal analysis, B.R.-K., M.A.C., R.C.G. and J.G. ; investigation, B.R.-K., M.A.C., R.C.G., J.G., J.S.C., G.P. and G.A.I. ; resources, S.V. ; data curation, M.A.C., R.C.G. and J.G. ; writing--review and editing, B.R.-K., C.Y.C. and G.A.I. ; visualization, S.V., R.C., G.R.C. and S.G.; project administration, B.R.-K.; funding acquisition, B.R.-K., G.P., G.R.C. and G.A.I. All authors have read and agreed to the published version of the manuscript. This work was partially supported by UNLP (X815), CONICET (PIBAA 0072, PIBAA 1078, PIP 0034, PIP 0671, PUE 0010), and ANPCyT (PICT2019-00199). The blood was obtained from the Institute of Hemotherapy, La Plata, Buenos Aires, Argentina, as part of a formal agreement between the IGEVET and this institution. Also, this assay protocol was approved by the National University of La Plata Ethics Committee, and it was developed in accordance with the principles proclaimed in the Universal Declaration of Human Rights of 1948, the ethical norms established by the Nuremberg Code of 1947, and the Declaration of Helsinki of 1964 and its successive amendments and clarifications.