br Fig Transmission electron microscopy
Fig. 2. Transmission electron microscopy (TEM) images (A, B), field emission scanning electron microscopy (FESEM) images (C) and selected-area electron dif-fraction (SAED) patterns (D) of CuO NPs.
Fig. 3. Energy-dispersive X-ray spectroscopy (EDS) spectrum of biosynthesized CuO NPs.
aptamer-conjugated siGLO-FAM-loaded NP after 60 min. Later, PBS was used to wash the cells, followed by detachment by trypsinization and centrifugation for 5 min at 1000 rpm. The obtained pellet was dissolved in PBS. The ABT263 were filtered using a 0.75 μm cell strainer before flow cytometry analysis to avoid cell aggregation, which creates tube lines that block the instrument.
The surface morphology and size of the CuO NPs was studied using
a JEOL JEM 2100 high-resolution transmission electron microscopy (HR-TEM) instrument (JEOL, Tokyo, Japan). About 100 μL of the pre-pared NP colloid was added to 1 mL of distilled water and kept in an ultrasonicator for 10 min. A drop of sonicated colloidal solution was dropped onto the copper grid surface and dried under vacuum, and was later visualized under a microscope. Simultaneous EDS analysis was conducted using the same instrument. X-ray diﬀraction (XRD) patterns for the prepared CuO NPs were obtained using a Bruker D8 Advance diﬀractometer (Bruker, Billerica, MA, USA), which was scanned at a rate of 4°/min, with Cu Kα radiation of λ = 1.54A° and a step size of
Fig. 4. (A) Dynamic light scattering (DLS) and (B) zeta potential of CuO NPs prepared using Coleus aromaticus extract.
Fig. 5. Fourier transform infrared spectroscopy (FT-IR) spectrum of biosynthesized CuO NPs.
Fig. 6. (A) SEM image of miRNA-conjugated CuO NPs. (B) Fluorescence micrograph of fluorescein isothiocyanate-mucin 1 (FITC-MUC1) aptamer-conjugated CuO NPs. (C) Fluorescent micrograph of CuO NPs not conjugated with MUC1 aptamer.
0.02°. Before analysis, the XRD instrument was calibrated using lan-thanum hexaboride (LaB6). Additionally, the mean particle size and surface charge of the synthesized CuO NPs were obtained using a na-noparticle analyzer (SZ-100; Horiba Scientific Nanoparticci, Edison, NJ, USA). A sample of CuO NPs dispersed in double distilled water was used for dynamic light scattering (DLS) analysis. The surface aping groups present on the CuO NPs were obtained using Fourier transform-infrared spectroscopy (FT-IR) analysis. Dried CuO NPs powder was studied using a JASCO FT-IR instrument (JASCO, Tokyo, Japan). A Leica DMI 6000B fluorescence microscope (Leica, Wetzlar, Germany) was used to obtain fluorescence micrograph images.
2.10. Statistical analysis
All the data in the manuscript was represented as mean ± Standard deviation. A Student's t-test test was performed for statistical sig-nificance and the obtained P-values less than 0.05 were considered as statistically significant.
3. Results and discussion
A water extract of Coleus aromaticus leaf was used as a reducing agent for the biosynthesis of CuO NPs. CuO NP formation was visually
Fig. 7. Cell viability of A549 cell lines induced by CuO NPs.
Fig. 8. In-vitro release profile showing the that optimum pH for mRNA release is pH 5 and only a limited amount of microRNA-29b was released at pH values 6.6 and 7.4.
observed after 20 min according to a color change of the reaction so-lution from dirty yellow to brown. A similar experiment was performed without adding the plant extract and the reaction solution was found to be unchanged after 3 days, indicating a role of Coleus aromaticus extract Materials Science & Engineering C 97 (2019) 827–832
in the synthesis of CuO NPs.
The HR-TEM and field emission scanning electron microscopy (FESEM) results, shown in Fig. 2, indicated the morphology and size of the prepared CuO NPs. The HR-TEM image confirmed that the obtained CuO NPs were spherical in shape with particle sizes ranging from 17 to 40 nm. The presence of bioconstituents from the Coleus aromaticus ex-tracts was also observed in the HR-TEM images (Fig. 2A,B). These biomolecules bound to the NP surfaces may a play key role in the sta-bility of the CuO nanocolloid [11,12]. FESEM microscopic images (Fig. 2C) showed spherical CuO NPs with sizes ranging from 21 to 48 nm, in agreement with the HR-TEM images. Similarly, the selected-area electron diﬀraction (SAED) pattern of the CuO NPs (Fig. 2D), showed the formation of polydispersed and crystalline NPs.
The elemental composition of the prepared CuO NPs was analyzed using EDS and the results are shown in Fig. 3. Strong signals corre-sponding to both copper and oxygen were observed at approximately 1 keV and 0.2 keV, respectively; no extra peaks related to impurities were observed, indicating the purity of the prepared CuO NPs. How-ever, there were some additional peaks present that may be ascribed to the presence of biomolecules in the CuO colloidal solution. Similar results have been observed for CuO NPs prepared using sublimated precursors [22,23].