Dextran-Assisted Biomimetic Fabrication of CdSe:Eu QDs With Enhanced Biocompatibility and Stability

A dextran templated biomimetic synthetic approach was applied for the preparation of Cadmium Selinium:Europium Quantum Dots (CdSe:Eu QDs). The present work examines synthetic variables including the effect of increasing Europium concentration during QDs' synthesis and the use of different coating agents (citrate versus APTES) to improve the QDs' colloidal stability and ameliorate their cytotoxic behavior. All samples were subjected to structural and morphological characterizations via Fourier Transform infrared (FT-IR) spectroscopy, UV-Visible (UV-Vis) spectrophotometry, Transmission Electron Microscopy (TEM), and Dynamic Light Scattering (DLS). Subsequently, biological evaluation of all the synthesized samples of bare and APTES coated CdSe:Eu QDs was conducted on epithelial HaCaT and breast cancer MCF-7. Wound healing assays were conducted to assess cytotoxicity and cell migration under QD treatment. Results showed that both coated and uncoated QDs influenced wound closure rates in a concentration- and time-dependent manner. Finally, fluorescence microscopy revealed significant green luminescence of CdSe:Eu quantum dots (QDs) in both HaCaT and MCF-7 cell lines, indicating efficient cellular uptake. The internalization of QDs was influenced by their surface properties and charge, suggesting an endocytic uptake pathway.