Multifunctional carbon dot anchored halloysite nanotube: Nanovehicle for cisplatin drug release, cytotoxicity on breast cancer cells and DNA binding studies

Abstract

Halloysite nanotube (HNT) is a clay material paving much attention in the field of biological studies. In the present work multifunctional carbon dot (CD) has been synthesized and functionalized with HNT that resulted in HNT-CD nanocomposite. Fabricated HNT-CD nanocomposite has been subjected to analytical and morphological characterization using XRD, FTIR, SEM and EDX techniques and indicates proper functionalization of CD with HNT. Cisplatin has been evaluated for drug loading efficiency for HNT and HNT-CD nanocomposite and found encapsulation efficiency and loading capacity is high for the nanocomposite. Cisplatin release studies with HNT and HNT-CD have been conducted at different pH. Cisplatin loaded with HNT and HNT- CD was further evaluated for in-vitro cytotoxicity test against MCF-7 cells. Cisplatin-loaded HNT- CD nanocomposite showed greater toxicity against MCF-7 cell lines compared to HNT alone. HNT-CD nanocomposite was further evaluated for its capacity to interact with Ct-DNA using UV–visible, Fluorescence spectrophotometry and circular dichroism using spectropolarimeter. The ∆G value for the HNT-CD was found to be 27.91 KJ mol −1 indicates a spontaneous binding process with Ct-DNA. The obtained n value close to 1, suggests the existence of a single binding site between the HNT-CD hybrid and Ct-DNA. The circular dichroism results are in good agreement with findings of the absorption and emission studies and indicate association with intercalative binding mode of HNT-CD hybrid with Ct-DNA.