Fig. 2: Overview of nanoparticle structural and functional characterization.

A FT-IR spectra of GO and increasing concentrations of cationic polymer functionalized GO^PEI1x, GO^PEI2x, GO^PEI3x. Conjugation of the carboxyl group of GO and the amino group of PEI was confirmed by FT-IR spectroscopy by measuring the characteristic peak of the amide bonds at 1630–1695 cm⁻¹. B TGA spectra of GO and GO^PEI was measured in the temperature range of 25-800 ˚C. The decomposition of components of the nanoformulation brought about by the mass loss at increasing temperatures was used to estimate the PEI content in GO^PEI. (C–E) DLS analyses of (C) hydrodynamic size, (D) ζ-potential, and (E) PDI of the nanoparticles GO, GO^PEI1x, GO^PEI2x, GO^PEI3x, and GO^PEI-mPEG. The particle sizes were 2354.6 ± 423, 318.7 ± 2.7, 206.0 ± 2.7, 274.8 ± 7.2, 347.4 ± 1.2, and 112 ± 1.2 nm, respectively. The ζ-potential were −40.4 ± 0.4, −48.1 ± 0.4, 55.2 ± 2.4, 50.1 ± 5.1, 57.3 ± 0.8, and 16.1 ± 0.6 mV, respectively. F In vitro evaluation of GO^PEI-siSCR aggregation at different ratios. A DLS study measuring the hydrodynamic size of GO^PEI-siSCR at different w/w ratios was carried out (n = 3) at the following ratios: 0.2:1, 0.5:1, 1:1, 2:1, 3:1, and 5:1. G Agarose gel retardation assay of the siSCR with GO and Cadmium quantum dots (CdQD) nanoparticles, respectively. GO and CdQD at various weight ratios of 2:1, 4:1, 6:1, 8:1, 10:1, 12:1, 14:1, 16:1, 18:1 and 20:1. Lipo²⁰⁰⁰, GO^PEI1x, GO^PEI2x, GO^PEI3x and GO^PEI-mPEG used w/w ratios of 0.25:1, 0.5:1, 0.75:1, 1:1, 1.25:1, 1.5:1, 1.75:1, 2:1, 2.25:1 and 2.5:1. Naked siSCR was used as negative control. The red frame represents the best complexation w/w proportion. All values are expressed as mean ± SD. ns- not significant and **p < 0.01 as analyzed using a two-tailed unpaired t-test.