Glycopolymer Decorated pH-Dependent Ratiometric Fluorescent Probe Based on Förster Resonance Energy Transfer for the Detection of Cancer Cells.

Development of fluorescent imaging probes is an important topic of research for the early diagnosis of cancer. Based on the difference between the cellular environment of tumor cells and normal cells, several "smart" fluorescent probes have been developed. In this work, a glycopolymer functionalized Förster resonance energy transfer (FRET) based fluorescent sensor is developed, which can monitor the pH change in cellular system. One-pot sequential reversible addition-fragmentation chain transfer (RAFT)polymerization technique is employed to synthesize fluorescent active triblock glycopolymer that can undergo FRET change on the variation of pH. A FRET pair, fluorescein o-acrylate (FA) and 7-amino-4-methylcoumarin (AMC) is linked via a pH-responsive polymer poly [2-(diisopropylamino)ethyl methacrylate] (PDPAEMA), which can undergo reversible swelling/deswelling under acidic/neutral condition. The presence of glycopolymer segment provides stability, water solubility, and specificity toward cancer cells. The cellular FRET experiments on cancer cells (MDA MB 231) and normal cells (3T3 fibroblast cells) demonstrate that the material is capable of distinguishing cells as a function of pH change.

Hydrothermal synthesis of gelatin quantum dots for high-performance biological imaging applications.

In the present study, we are reporting a one-pot synthesis of gelatin quantum dots (GeQDs) by the hydrothermal process. The synthesized GeQDs were characterized by fourier transform infrared spectroscopy, nuclear magnetic resonance, ultraviolet-visible and photoluminescence spectroscopic techniques, and also by using high-resolution transmission electron microscopy. The GeQDs showed a high level of photoluminescence quantum yield (PLQY) with significantly higher stability for up to 6 months and presented similar fluorescent intensity as the initial PLQY without any precipitation and aggregation at ambient condition. The cell imaging ability of synthesized GeQDs was examined using cells belonging to diverse clinical backgrounds like bacterial cells including Escherichia coli and Staphylococcus aureus, yeast cells including Candida albicans, C. krusei, C. parapsilosis, and C. tropicalis, mycelial fungi including Aspergillus flavus and A. fumigatus cells, cancer cell lines A549, HEK293 and L929. The results demonstrated that the GeQDs illuminates the cells and can be utilized as potential cell labeling non-toxic biomarkers. In conclusion, it can be said that the gelatin stabilized QDs are a promising candidate for stable and long-term fluorescent imaging of different types of cells.

REDOX Responsive Fluorescence Active Glycopolymer Based Nanogel: A Potential Material for Targeted Anticancer Drug Delivery.

A well-defined glycopolymer based fluorescence active nanogel has been prepared via the combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and Diels-Alder (DA) "click" chemistry. To prepare the nanogel, initially, a functional AB block copolymer (BCP) poly(pentafluorophenyl acrylate)-b-poly(furfuryl methacrylate) (PPFPA-b-PFMA), having activated pentafluorophenyl ester group, was synthesized via RAFT polymerization. The activated pentafluorophenyl functionality was replaced by the amine functionality of glucosamine to introduce the amphiphilic BCP poly[2-(acrylamido) glucopyranose]-b-poly(furfuryl methacrylate) (PAG-b-PFMA). Furthermore, the terminal acid (-COOH) functionality of the RAFT agent was modified by gelatin QDs (GQDs) to generate fluorescence active glycopolymer. An anticancer drug, Doxorubicin, was loaded in the micelle via the successive addition of the drug molecule and cross-linking using dithio-bismaleimidoethane (DTME), a REDOX responsive cross-linker. The anticancer activity of the drug loaded nanogel was observed over MBA-MD-231, human breast cancer cell line, and monitored via fluorescence spectroscopy and flow cytometric analyses (FACS). The cytotoxicity of the prepared glycopolymer based nanogel over the MBA-MD-231 cell line was assessed via MTT assay test, and it was observed that the synthesized nanogel was noncytotoxic in nature.