Cytotoxicity and Cellular Localization of PEGylated and Peptide-Modified Carbon Quantum Dots (CQDs)
E-MRS 2026 Fall Meeting, Warszawa, Polonya, 14 - 17 Eylül 2026, (Yayınlanmadı)
- Yayın Türü: Bildiri / Yayınlanmadı
- Basıldığı Şehir: Warszawa
- Basıldığı Ülke: Polonya
- Acıbadem Mehmet Ali Aydınlar Üniversitesi Adresli: Evet
Özet
Carbon quantum dots (CQDs) are 0D nanocarbons with high chemical and photostability, small size (< 10 nm), tunable excitation and emission, and easy surface functionalization, making them preferred as bioimaging agents, biosensors, and in drug delivery systems. Although the modification of the CQDs with various peptides and PEGylation of them are widely used, their combined effects on cell viability, cellular localization and apoptosis remain insufficiently explored. Therefore, this study aimed to investigate the effects of PEGylation and peptide adsorption of CQDs on HEK293 and MCF-7 cells’ viability, localization, and apoptosis. CQDs were synthesized with a bottom-up hot bubble synthesis (HBBBS) method, developed by our group. The synthesized CQD were PEGylated with 0.001M PEG-10 dissolved in acetone in a non-covalent manner. The amphipathic cell penetrating peptide, Pep-1, was physically adsorbed onto bare or PEGylated CQDs (CQD-PEG) via non-covalent interactions. CQDs, CQD-PEG, CQD-Pep-1 and CQD-PEG-Pep-1 complexes all exhibited spherical morphology, showed an absorbance peak below 250 nm corresponding to π–π transitions of the CQDs, gave fluorescent signals when excited with 385 nm, had -41.37 mV, -28.87 mV, -1.70 mV, and -2.89 mV surface charge, and had 7 nm, 154.0 nm, 284.8 nm, and 263.8 nm hydrodynamic diameter, respectively. Additionally, CQD-Pep-1 and CQD-PEG-Pep-1 complexes showed an absorbance peak at 280 nm, and showed peaks at 1262 cm-1 and 1672 cm-1 corresponding to amide III and amide I bonds confirming the peptide adsorption. Cytotoxicity of the materials on HEK293 and MCF-7 cells was evaluated for 24h and 48h via CCK-8 kit. CQD-Pep-1 and CQD-PEG-Pep-1 complexes were found to be not cytotoxic at the highest concentration (10 µM) in 48h despite inducing ~30% viability loss in HEK293 cells. PEGylated CQDs exhibited lower IC50 values than bare CQDs for both cell lines and incubation times regarding the peptide presence which could result from the better internalization of the PEGylated complexes in cells compared to non-PEGylated materials. CQD and CQD-PEG began to internalize at 4h and 6h incubation time for HEK293 and MCF-7 cells, respectively, but PEGylated CQDs were internalized more compared to bare CQDs for both cell lines supporting the cell viability results. For both CQD and CQD-PEG, full cellular internalization was achieved within 24h in HEK293 cells whereas MCF-7 cells reached full internalization at 48h. The effect of the materials on apoptosis in 48h is currently being investigated at the protein level via checking specific protein levels (total and cleaved caspase-3, BCL-2 and Bax). In conclusion, this study demonstrates that PEGylation and Pep-1 adsorption can modulate the cellular uptake, cell viability, and potentially the apoptotic responses to CQDs, highlighting their potential as theranostic agents.
Keywords: Carbon quantum dots, Surface functionalization, Cytotoxicity, Cellular localization