Carbon dots incorporated polymeric hydrogels as multifunctional platform for imaging and induction of apoptosis in lung cancer cells.
Multifunctional hydrogels offer a seemingly efficient system for delivery of drugs and bioimaging modalities. The present study deals with the facile development of chitosan based hydrogel formulation composed of highly fluorescent carbon dots (CDs) and loaded with a model anticancer drug, 5 Fluorouracil (5 FU) Herein, CDs were embedded firmly within the hydrogel matrices (CD HY) via non covalent interactions during the ionic cross linking reaction. Furthermore, these hydrogels could effectively encapsulate 5 FU through hydrophobic interactions to form 5 FU@CD HY. In this way, it was possible to combine the merits of both CDs and 5 FU on a common platform for monitoring the cellular uptake as well as therapeutic effects. Field emission scanning electron microscopy (FE SEM) transmission electron microscopy (TEM) Fourier transform infrared spectroscopy (FTIR) thermogravimetric analysis (TGA) illustrated the porous nature and formation of 5 FU@CD HY. Besides, functional characteristics of 5 FU@CD HY such as surface area, mechanical strength, swelling behavior and drug release were investigated. In vitro studies revealed the multifunctional aspects of 5 FU@CD HY in monitoring the cellular uptake and inflicting apoptosis in A549 cells. Green fluorescence of CDs in 5 FU@CD HY aided the qualitative and quantitative assessment of cellular uptake. In addition to this, the fluorescence of CDs could be used to detect apoptosis instigated by 5 FU, eliminating the need for multiplex dyes. Induction of apoptosis in 5 FU@CD HY treated cells was evidenced by changes in cell cycle distributions and visualization of characteristic apoptotic bodies through FE SEM. Apoptotic gene expression studies further elucidate the molecular mechanism involved in eliciting apoptosis. Thus, hydrogels mediated integration of fluorescent CDs with chemotherapeutic agents provides a new dimension for the potential use of hydrogels in cancer theranostics.
Colloids and surfaces. B, Biointerfaces