Dual (pH- and ROS-) Responsive Antibacterial MXene-Based Nanocarrier for Drug Delivery

Abstract

In this study, a novel MXene (Ti3C2Tx)-based nanocarrier was developed for drug delivery. MXene nanosheets were functionalized with 3, 3′-diselanediyldipropionic acid (DSeDPA), followed by grafting doxorubicin (DOX) as a model drug to the surface of functionalized MXene nanosheets (MXene-Se-DOX). The nanosheets were characterized using scanning electron microscopy, atomic force microscopy (AFM), transmission electron microscopy, energy-dispersive X-ray spectroscopy (EDX), nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and zeta potential techniques. The drug-loading capacity (17.95%) and encapsulation efficiency (41.66%) were determined using ultraviolet–visible spectroscopy. The lateral size and thickness of the MXene nanosheets measured using AFM were 200 nm and 1.5 nm, respectively. The drug release behavior of the MXene-Se-DOX nanosheets was evaluated under different medium conditions, and the nanosheets demonstrated outstanding dual (reactive oxygen species (ROS)- and pH-) responsive properties. Furthermore, the MXene-Se-DOX nanosheets exhibited excellent antibacterial activity against both Gram-negative E. coli and Gram-positive B. subtilis.

Potential Biosafety of Mxenes: Stability, Biodegradability, Toxicity and Biocompatibility

“…In addition, small-sized MXenes penetrate into the cytoplasm by endocytosis and damage the cells inside. [15,16,31,74,75] Pro-oxidant action and induction of oxidative stress, which may led to cell death, [76][77][78] is another possible mechanism of toxicity. MXenes produce superoxide anion radical (O 2*À ) and hydroxyl radical (HO * ), when interacting with O 2 and H 2 O, respectively.…”

“…[91] However, in many cases MXenes are equally toxic to both types of bacteria. [31,32,74,75,90] This may be due to additional mechanisms of action. In particular, MXenes can bind to lipopolysaccharides and prevent nutrient absorption.…”

“…[18][19][20][21] In part, the anti-inflammatory effect can be explained by the antioxidant properties, which are confirmed by some studies of MXenes as mimetics of antioxidant enzymes. [22][23][24][25] In addition, MXenes are effectively applied for photothermal, sonodynamic, and thermogaseous therapy of cancer, [26][27][28][29][30] construction of nanoplatforms that deliver/release drugs, [24,[30][31][32] and in tissue regeneration studies. [33][34][35][36] In addition, they have significant potential for use in bioimaging.…”

Recent advances using MXenes in biomedical applications

“…Zhang and co-workers developed an MXene nanocarrier with dual responsiveness (pH and reactive oxygen species, ROS) to control drug release behaviors. 24 First, the MXene surface was modified to an amine-rich interface and then doxorubicin was bound using 3,3′-diselenodiyldipropionic acid (DSeDPA) as a cross-linker. During the conjugation process, DSeDPA can first form an amide bond on the MXene surface, and then the remaining carboxylic acid groups on DSeDPA provide a site for conjugation with doxorubicin (DOX) molecules through an EDC/NHS reaction, resulting in the generation of MXene-Se-DOX.…”

Research Progress on Ti3C2Tx-Based Composite Materials in Antibacterial Field

“…By grafting doxorubicin (DOX) as a model drug onto functionalized Ti 3 C 2 T x nanosheets, a nanoparticle with exceptional drug loading and encapsulation efficiency, as well as outstanding dual (ROS- and pH-responsive) properties, is achieved. Moreover, Ti 3 C 2 T x -DOX nanosheets exhibit excellent antibacterial activity against both Gram-negative E. coli and Gram-positive B. subtilis [ 202 ]. Incorporating Ti 3 C 2 T x into a modified polyurethane enhances its physicochemical properties and biocompatibility.…”