A Label-Free and Ultrasensitive Prussian Blue-Based Dipstick Sensor for Bacterial and Biofilm Detection.

Water and food contamination has become the major contributor to infections and deaths. However, rapid and sensitive bacterial detection still remains an unmet demand that has attracted widespread attention. Often water and food samples are sent out for laboratory testing to detect the presence of contamination, which is time-consuming and laborious. Herein, we have developed a highly sensitive, tenable, affordable, and robust (STAR) paper-based colorimetric dipstick sensor based on the principle of Prussian blue (PB) synthesis as an indicator of bacterial contamination. In the presence of bacteria, it leads to the formation of PB, a dye that acts as a colorimetric indicator. The intensity of the PB is the direct measure of the degree of contamination. The fabrication of the STAR dipstick sensor involves a simple and cost-effective process. The STAR dipstick sensor is ultrasensitive and can detect up to 101 CFU/mL of bacteria within minutes of contact with the test sample. The STAR dipstick sensor is fabricated using biodegradable components, which is speculated to facilitate quick and environmentally friendly degradation after each use. The sensor has been validated for its properties and capabilities at different pH to detect both Gram-positive and Gram-negative bacterial strains in real-time samples. The stability and degradation were also monitored. Comprehensively, the proposed STAR dipstick sensor can serve as a point-of-care device to detect bacterial contamination in a swift and sensitive manner.

Cisplatin Encapsulated Plasmonic Blackbodies for NIR Light Activatable Chemo-Phototherapy and Reduction of 4-Nitrophenol.

Cisplatin (CDDP) is an FDA-approved chemotherapeutic drug used for treating various solid tumors. Despite of its effectiveness towards chemotherapy, it faces several challenges, such as multi-drug resistance (MDR) and significant damage to the normal tissues. To address these challenges, various nanoformulations were developed to improve the delivery and safety of CDDP. One of the limitation in these CDDP loaded nanoformulations is that the effective CDDP loading concentrations are very poor. Therefore, this leaves a grand challenge to develop an effective strategy to carry higher concentrations of CDDP molecules, and also simultaneously exhibit very unique properties. Herein, we have developed an one-pot synthesis of Cisplatin encapsulated Plasmonic blackbody (CiP), which offers a double play for near infrared (NIR) light activatable chemo-photothermal therapy in destructing cancer cells as well as mediate catalytic reduction of 4-nitrophenol (4-NP). The CiP nanoformulation exhibits superior light absorbing capabilities in the NIR region with an appreciable photothermal conversion efficiency of 41%. Further, NIR light activatable combinatorial therapeutic approach of CiP was demonstrated against ovarian cancer cells and as a catalyst for the reduction of model pollutant 4-nitrophenol. Our findings highlight the potential of CiP as a versatile platform for light-activated combinatorial cancer therapy and environmental pollutant remediation.

Facile Synthesis of Multifunctional Carbon Dots Derived from Camel Milk for Mn7+ Sensing and Antiamyloid and Anticancer Activities.

Carbon dots (CDs) are promising biocompatible fluorescent nanoparticles mainly used in bioimaging, drug delivery, sensing, therapeutics, and various other applications. The utilization of natural sources and green synthetic approaches is resulting in highly biocompatible and nontoxic nanoparticles. Herein, we report an unprecedented facile and green synthesis of highly luminescent carbon dots derived from camel milk (CM) for sensing manganese (Mn7+) ions and for identifying the anticancer potential and antiamyloid activity against α-synuclein amyloids. α-Synuclein amyloid formation due to protein misfolding (genetic and environmental factors) has gained significant attention due to its association with Parkinson's disease and other synucleinopathies. The as-synthesized CM-CDs possess an average hydrodynamic diameter ranging from 3 to 15 nm and also exhibit strong photoluminescence (PL) emission in the blue region. The CM-CDs possess good water dispersibility, stable fluorescence under different physical states, and outstanding photostability. Moreover, the CM-CDs are validated as an efficient sensor for the detection of Mn7+ ions in DI water and in metal ion-polluted tap water. In addition, the CM-CDs have demonstrated a very good quantum yield (QY) of 24.6% and a limit of detection (LOD) of 0.58 µM for Mn7+ ions with no incubation time. Consequently, the exceptional properties of CM-CDs make them highly suitable for a diverse array of biomedical applications.

Optical Characteristics of Indocyanine Green J-Aggregates Induced by Cisplatin for Phototheranostic Applications.

The development of an optical system for combinatorial theranostics is of significant interest. Clinical translation of such theranostic agents need to cross several barriers. Herein, we have developed a facile method for the preparation of J-aggregates using FDA approved agents, namely, NIR fluorophore indocyanine green (ICG) and a chemotherapeutic drug, cisplatin (CDDP), which induces ICG to form indocyanine green J-aggregates (IJAs). The formation of IJAs has been characterized by the formation of a new absorption peak centered at ∼896 nm. The existing methods to synthesize IJAs have used several harsh reaction conditions, such as elevated temperatures, for a prolonged time duration (∼60 days). To the best of our knowledge, for the first time, we have reported the formation of IJAs assisted by CDDP at 37 °C temperature within 12 h. The presence of CDDP in ICG favors IJA formation and thereby reduces the harshness of the reaction conditions in the conventionally followed protocols. Moreover, the presence of CDDP can facilitate photoactivated combinatorial therapy. The as synthesized IJA optical system has superior properties to those of free ICG, in terms of diagnostic and therapeutic capabilities (being activatable at ∼896 nm wavelength, which can achieve deeper tissue penetration) and excellent optical and storage stability. The facile synthesis proposed along with CDDP incorporation makes the optical system a clinically relevant one-component theranostic agent.

Recent Progress in Red Blood Cells-Derived Particles as Novel Bioinspired Drug Delivery Systems: Challenges and Strategies for Clinical Translation.

Red Blood Cells (RBCs)-derived particles are an emerging group of novel drug delivery systems. The natural attributes of RBCs make them potential candidates for use as a drug carrier or nanoparticle camouflaging material as they are innately biocompatible. RBCs have been studied for multiple decades in drug delivery applications but their evolution in the clinical arena are considerably slower. They have been garnering attention for the unique capability of conserving their membrane proteins post fabrication that help them to stay non-immunogenic in the biological environment prolonging their circulation time and improving therapeutic efficiency. In this review, we discuss about the synthesis, significance, and various biomedical applications of the above-mentioned classes of engineered RBCs. This article is focused on the current state of clinical translation and the analysis of the hindrances associated with the transition from lab to clinic applications.