A Dual signal On-Off Fluorescent Nanosensor for the Simultaneous Detection of Copper and Creatinine

We report the synthesis and design of a quantum dot based multi analyte sensor by tuning its optical properties such that it has two independent emission profiles, sensitive to two analytes. The sensing has been proven in cellular environment and blood serum. A strip based sensor was also designed which work based on a mobile app which is validated on human blood from 4 volunteers.</p

Doxorubicin-Polysorbate 80 Conjugates: Targeting Effective and Sustained Delivery to the Brain

Targeting therapeutic agents to the brain to treat the central nervous system (CNS) diseases is a major challenge due to the blood-brain-barrier (BBB). In this study, an attempt was made to deliver a model drug such as doxorubicin (DOX) to the brain in a mice model through DOX-Polysorbate 80 (DOX-PS80) conjugates. DOX was successfully conjugated with the non-ionic surfactant Polysorbate 80 (PS80) by carbamate linkage and the conjugate was characterized by different spectroscopic techniques such as FTIR, UV-Visible and NMR. The DOX conjugation efficacy was found to be 43.69 ± 4.72 %. The in vitro cumulative release of DOX from the conjugates was found to be 4.9 ± 0.8 % in PBS of pH 7.3 and 3.9 ± 0.6 % in simulated cerebrospinal fluid (CSF) of pH 7.3 at the end of 10 days. In vitro BBB permeability assay was carried out using bEnd.3 cells and DOX-PS80 conjugate showed a 3-fold increase in BBB permeability compared to controls. In vitro cytotoxicity assay using U251 human glioblastoma cells showed an IC50 value of 38.10 µg/mL for DOX-PS80. Cell uptake studies revealed that DOX-PS80 was effectively taken up (90%) by the bEnd.3 and U251 cells and localized in cytoplasm at the end of 24 h. Tumor spheroid assay and in vivo experiments in Swiss albino mice demonstrated the possibility of DOX-PS80 conjugate crossing the BBB and delivering the drug molecules to the target site for treating CNS disorders

Fluorescence Imaging Assisted Photodynamic Therapy Using Photosensitizer-Linked Gold Quantum Clusters

Fluorescence imaging assisted photodynamic therapy (PDT) is a viable two-in-one clinical tool for cancer treatment and follow-up. While the surface plasmon effect of gold nanorods and nanoparticles has been effective for cancer therapy, their emission properties when compared to gold nanoclusters are weak for fluorescence imaging guided PDT. In order to address the above issues, we have synthesized a near-infrared-emitting gold quantum cluster capped with lipoic acid (L-AuC with (Au)₁₈(L)₁₄) based nanoplatform with excellent tumor reduction property by incorporating a tumor-targeting agent (folic acid) and a photosensitizer (protoporphyrin IX), for selective PDT. The synthesized quantum cluster based photosensitizer PFL-AuC showed 80% triplet quantum yield when compared to that of the photosensitizer alone (63%). PFL-AuC having 60 μg (0.136 mM) of protoporphyrin IX was sufficient to kill 50% of the tumor cell population. Effective destruction of tumor cells was evident from the histopathology and fluorescence imaging, which confirm the <i>in vivo</i> PDT efficacy of PFL-AuC

Biosafety of citrate coated zerovalent iron nanoparticles for Magnetic Resonance Angiography

Though nanoparticles are being used for several biomedical applications, the safety of the same is still a concern. It is very routine procedure to check the preliminary safety aspects of the particles intended for in vivo applications. The major tests include how the material reacts to a normal cell, how it behaves with the blood cells and also whether any lysis take place in the presence of these materials. Here we present these test data of two novel nanomaterials designed for its use as contrast agent for magnetic resonance imaging and a multimodal contrast agent for targeted liver imaging. On proving the biosafety, the materials were tested for Magnetic Resonance Angiography using normal rats as model. The data of the same were clear identification of the prominent vascular structures and is included as the colour coded MRI image. Lateral and oblique view data are also presented for visualizing other major blood vessels

Engineering of Tripeptide-Stabilized Gold Nanoclusters with Inherent Photosensitizing Property for Bioimaging and Photodynamic Therapy

Gold nanoclusters have the characteristics of small size, unique optical properties, and eco-friendly synthesis that make them promising candidates for biomedical applications, especially for bioimaging. However, their inherent photochemical activity and therapeutic efficiency are largely unknown and remain unexplored. Here, we report a simple one-step green synthesis procedure for the preparation of two tripeptide-stabilized silver-doped gold nanoclusters (TPGNCs) and their photodynamic therapeutic effect on cancer cells and simultaneous imaging. The custom-designed tripeptides were used for the preparation of silver-doped gold nanoclusters with enhanced fluorescence emission. These TPGNCs exhibited strong red fluorescence with high quantum yield, large Stokes shift, good photostability, and excellent biocompatibility toward normal cells. TPGNCs imparted minimum dark toxicity toward breast cancer cells. These TPGNCs exhibited appreciable photosensitization to generate ROS within the cancer cells triggering loss of mitochondrial membrane potential, leading to apoptotic cell death. The photosensitizing ability of TPGNCs will be a new avenue in the area of photoinduced cancer therapy with negligible side effects

Near infrared-emitting multimodal nanosystem for in vitro magnetic hyperthermia of hepatocellular carcinoma and dual imaging of in vivo liver fibrosis

Abstract Prolonged usage of traditional nanomaterials in the biological field has posed several short- and long-term toxicity issues. Over the past few years, smart nanomaterials (SNs) with controlled physical, chemical, and biological features have been synthesized in an effort to allay these challenges. The current study seeks to develop theranostic SNs based on iron oxide to enable simultaneous magnetic hyperthermia and magnetic resonance imaging (MRI), for chronic liver damage like liver fibrosis which is a major risk factor for hepatocellular carcinoma. To accomplish this, superparamagnetic iron oxide nanoparticles (SPIONs) were prepared, coated with a biocompatible and naturally occurring polysaccharide, alginate. The resultant material, ASPIONs were evaluated in terms of physicochemical, magnetic and biological properties. A hydrodynamic diameter of 40 nm and a transverse proton relaxation rate of 117.84 mM−1 s−1 pronounces the use of ASPIONs as an efficient MRI contrast agent. In the presence of alternating current of 300 A, ASPIONs could elevate the temperature to 45 °C or more, with the possibility of hyperthermia based therapeutic approach. Magnetic therapeutic and imaging potential of ASPIONs were further evaluated respectively in vitro and in vivo in HepG2 carcinoma cells and animal models of liver fibrosis, respectively. Finally, to introduce dual imaging capability along with magnetic properties, ASPIONs were conjugated with near infrared (NIR) dye Atto 700 and evaluated its optical imaging efficiency in animal model of liver fibrosis. Histological analysis further confirmed the liver targeting efficacy of the developed SNs for Magnetic theranostics and optical imaging as well as proved its short-term safety, in vivo

Light induced damage and repair in nucleic acids and proteins: general discussion Faraday Discussions

International audienc

Bionanophotonics: general discussion Faraday Discussions

International audienc