Species-Specific Plant-Derived Nanoparticle Characteristics.

Medicinal and agricultural plants contain numerous phytochemical compounds with pronounced biological effects on human health. They are known to encapsulate most of their characteristic bioactive compounds within membranous elements of intercellular communication known as exosomes. These nanovesicles serve as capsules protecting their biological activity and improving their penetration into the tissue. Therefore, the application of plant exosome preparations holds considerable potential for cosmetics and pharmacy, but the quality and consistency of plant material for exosome isolation is of critical importance. Therefore, in this study, we aimed to evaluate yield, size distribution patterns, and antioxidant properties between nanovesicle preparations of the following portfolio of medicinal plants: Kalanchoe daigremontiana, Artemisia absinthium, Hypericum perforatum, Silybum marianum, Chelidonium majus, and Scutellaria baicalensis. Results showed that nanoparticle yield, size distribution, and antioxidant activities were specific to plant species. Compared to other plants, nanoparticle preparations from Artemisia absinthium were distinguished by remarkably higher yield and concentration, while the highest antioxidant activity of plant-derived nanoparticle preparations per weight and per particle was determined to occur in Chelidonium majus and Hypericum perforatum samples. Results showed no significant correlation in DPPH (2-diphenyl-1-picrylhydrazyl) free radical scavenging activity and FRAP (ferric reducing antioxidant power) between plant material and nanoparticle preparations. More detailed biochemical analysis of exosome preparations is necessary to validate their biological activity and its relation to source plant cells.

Investigation of Cancer Cell Migration and Proliferation on Synthetic Extracellular Matrix Peptide Hydrogels.

Chemical and mechanical properties of a tumor microenvironment are essential players in cancer progression, and it is important to precisely control the extracellular conditions while designing cancer in vitro models. The study investigates synthetic hydrogel matrices from multi-arm polyethylene glycol (PEG) functionalized with collagen-like peptide (CLP) CG(PKG)4(POG)4(DOG)4 alone and conjugated with either cell adhesion peptide RGD (mimicking fibronectin) or IKVAV (mimicking laminin). Human glioblastoma HROG36, rat C6 glioma cells, and A375 human melanoma cells were grown on the hydrogels and monitored for migration, proliferation, projected cell area, cell shape index, size and number, distribution of focal contacts in individual cells, and focal adhesion number. PEG-CLP-RGD induced migration of both glioma cell lines and also stimulated proliferation (assessed as metabolic activity) of HROG36 cells. Migration of C6 cells were also stimulated by PEG-CLP-IKVAV. These responses strongly correlated with the changes in adhesion and morphology parameters of individual cells - projected cell area, cell shape index, and focal contact number. Melanoma A375 cell proliferation was increased by PEG-CLP-RGD, and this was accompanied by a decrease in cell shape index. However, neither RGD nor IKVAV conjugated to PEG-CLP stimulated migratory capacity of A375 cells. Taken together, the study presents synthetic scaffolds with extracellular matrix (ECM)-mimicking peptides that allow for the exploration of the effect of ECM signaling to cancer cells.