Many photosensitive substances suitable for photodynamic therapy (PDT) have limited applications due to their insufficient solubility in polar solvents. Our research overcomes this challenge by means of nanotechnology in order to transform hydrophobic compounds into stable aqueous solutions, enabling them to use their full potential and unique properties in cancer therapy. In this study, the novel nano-composite cGQDs-PEG-curcumin was developed to overcome the insolubility of curcumin in water and its extraordinary efficacy in PDT was evaluated. Complex characterization was performed using high-resolution transmission electron microscopy (HR-TEM), FTIR, and UV-Vis spectroscopy. Further analysis involved fluorescence lifetime imaging (FLIM), and its cellular localization was mapped with confocal microscopy. In order to evaluate PDT effectiveness, cells treated with cGQDs-PEG-curcumin were irradiated with 5 J/cm2 of 414 nm light. After irradiation, cell viability assay, scanning electron microscopy (SEM), reactive oxygen species (ROS) detection, comet assay, and γH2AX-based DNA double-strand breaks (DSBs) detection were assessed and revealed a remarkable ability of the nano-composite to induce DNA damage after irradiation without ROS production. Our findings highlight the potential of cGQDs-PEG-curcumin as a cutting-edge PDT agent, capable of disrupting cell membrane and nucleolar integrity and impairing ribosomal synthesis, which is crucial for proliferating tumour cells.
- MeSH
- Cell Nucleolus * drug effects metabolism MeSH
- DNA Breaks, Double-Stranded drug effects MeSH
- Photochemotherapy * methods MeSH
- Photosensitizing Agents * pharmacology MeSH
- Graphite * chemistry pharmacology MeSH
- Curcumin * pharmacology chemistry MeSH
- Quantum Dots * chemistry MeSH
- Humans MeSH
- Cell Line, Tumor MeSH
- Neoplasms * drug therapy MeSH
- Polyethylene Glycols * chemistry pharmacology MeSH
- DNA Damage * drug effects MeSH
- Reactive Oxygen Species metabolism MeSH
- Cell Survival drug effects MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
In recent years, multifunctional nanocarriers that provide simultaneous drug delivery and imaging have attracted enormous attention, especially in cancer treatment. In this research, a biocompatible fluorescent multifunctional nanocarrier is designed for the co-delivery of capsaicin (CPS) and nitrogen-doped graphene quantum dots (N-GQDs) using the pH sensitive amphiphilic block copolymer (poly(2-ethyl-2-oxazoline)-b-poly(ε-caprolactone), PEtOx-b-PCL). The effects of the critical formulation parameters (the amount of copolymer, the concentration of poly(vinyl alcohol) (PVA) as a stabilizing agent in the inner aqueous phase, and volume of the inner phase) are evaluated to achieve optimal nanoparticle (NP) properties using Central Composite Design. The optimized NPs demonstrated a desirable size distribution (167.8 ± 1.4 nm) with a negative surface charge (-19.9 ± 0.4) and a suitable loading capacity for CPS (70.80 ± 0.05%). The CPS & N-GQD NPs are found to have remarkable toxicity on human breast adenocarcinoma cell line (MCF-7). The solid fluorescent signal is acquired from cells containing multifunctional NPs, according to the confocal microscope imaging results, confirming the significant cellular uptake. This research illustrates the enormous potential for cellular imaging and enhanced cancer therapy offered by multifunctional nanocarriers that combine drug substances with the novel fluorescent agents.
- MeSH
- Nitrogen * chemistry MeSH
- Fluorescent Dyes chemistry MeSH
- Graphite * chemistry MeSH
- Capsaicin * chemistry pharmacology MeSH
- Quantum Dots * chemistry therapeutic use MeSH
- Humans MeSH
- MCF-7 Cells MeSH
- Nanoparticles * chemistry MeSH
- Drug Carriers chemistry MeSH
- Polymers chemistry MeSH
- Antineoplastic Agents * pharmacology chemistry MeSH
- Theranostic Nanomedicine * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- MeSH
- Cerium analysis MeSH
- Electromagnetic Radiation MeSH
- Physical Phenomena MeSH
- Hyperthermia, Induced methods MeSH
- Quantum Dots MeSH
- Magnetic Phenomena * MeSH
- Magnetics MeSH
- Neoplasms therapy MeSH
- Nanoparticles * chemistry therapeutic use ultrastructure MeSH
- Nanotechnology methods trends MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
NMDA receptors (NMDARs) are ionotropic glutamate receptors that play a key role in excitatory neurotransmission. The number and subtype of surface NMDARs are regulated at several levels, including their externalization, internalization, and lateral diffusion between the synaptic and extrasynaptic regions. Here, we used novel anti-GFP (green fluorescent protein) nanobodies conjugated to either the smallest commercially available quantum dot 525 (QD525) or the several nanometer larger (and thus brighter) QD605 (referred to as nanoGFP-QD525 and nanoGFP-QD605, respectively). Targeting the yellow fluorescent protein-tagged GluN1 subunit in rat hippocampal neurons, we compared these two probes to a previously established larger probe, a rabbit anti-GFP IgG together with a secondary IgG conjugated to QD605 (referred to as antiGFP-QD605). The nanoGFP-based probes allowed faster lateral diffusion of the NMDARs, with several-fold increased median values of the diffusion coefficient (D). Using thresholded tdTomato-Homer1c signals to mark synaptic regions, we found that the nanoprobe-based D values sharply increased at distances over 100 nm from the synaptic edge, while D values for antiGFP-QD605 probe remained unchanged up to a 400 nm distance. Using the nanoGFP-QD605 probe in hippocampal neurons expressing the GFP-GluN2A, GFP-GluN2B, or GFP-GluN3A subunits, we detected subunit-dependent differences in the synaptic localization of NMDARs, D value, synaptic residence time, and synaptic-extrasynaptic exchange rate. Finally, we confirmed the applicability of the nanoGFP-QD605 probe to study differences in the distribution of synaptic NMDARs by comparing to data obtained with nanoGFPs conjugated to organic fluorophores, using universal point accumulation imaging in nanoscale topography and direct stochastic optical reconstruction microscopy.SIGNIFICANCE STATEMENT Our study systematically compared the localization and mobility of surface NMDARs containing GFP-GluN2A, GFP-GluN2B, or GFP-GluN3A subunits expressed in rodent hippocampal neurons, using anti-green fluorescent protein (GFP) nanobodies conjugated to the quantum dot 605 (nanoGFP-QD605), as well as nanoGFP probes conjugated with small organic fluorophores. Our comprehensive analysis showed that the method used to delineate the synaptic region plays an important role in the study of synaptic and extrasynaptic pools of NMDARs. In addition, we showed that the nanoGFP-QD605 probe has optimal parameters for studying the mobility of NMDARs because of its high localization accuracy comparable to direct stochastic optical reconstruction microscopy and longer scan time compared with universal point accumulation imaging in nanoscale topography. The developed approaches are readily applicable to the study of any GFP-labeled membrane receptors expressed in mammalian neurons.
- MeSH
- Hippocampus metabolism MeSH
- Immunoglobulin G metabolism MeSH
- Single-Domain Antibodies * metabolism MeSH
- Rabbits MeSH
- Rats MeSH
- Neurons metabolism MeSH
- Receptors, N-Methyl-D-Aspartate * metabolism MeSH
- Mammals MeSH
- Synapses physiology MeSH
- Animals MeSH
- Check Tag
- Rabbits MeSH
- Rats MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
With the goal to investigate biological phenomena at a single-cell level, we designed, synthesized and tested a molecular probe based on Förster resonance energy transfer (FRET) between a highly luminescent quantum dot (QD) as a donor and a fluorophore or fluorescence quencher as an acceptor linked by a specific peptide. In principle, QD luminescence, effectively dissipated in the probe, is switched on after the cleavage of the peptide by a protease and the release of the quencher. We proposed a novel synthesis strategy of a probe. A two-step synthesis consists of: (i) Conjugation of CdTe QDs functionalized by -COOH groups of succinic acid on the nanoparticle surface with the designed specific peptide (GTADVEDTSC) using a ligand-exchange approach; (ii) A fast, high-yield reaction of amine-reactive succinimidyl group on the BHQ-2 quencher with N-terminal of the peptide. This way, any crosslinking between individual nanoparticles and any nonspecific conjugation bonds are excluded. The analysis of the product after the first step proved a high reaction yield and nearly no occurrence of unreacted QDs, a prerequisite of the specificity of our luminescent probe. Its parameters evaluated as Michaelis-Menten description of enzymatic kinetics are similar to products published by other groups. Our research is focused on the fluorescence microscopy analyses of biologically active molecules, such as proteolytic active caspases, playing important roles in cell signaling regulations in normal and diseased states. Consequently, they are attractive targets for clinical diagnosis and medical therapy. The ultimate goal of our work was to synthesize a new QD luminescent probe for a long-time quantitative monitoring of active caspase-3/7 distribution in apoptotic osteoblastic MC3T3-E1 cells treated with camptothecin. As a result of comparison, our synthetized luminescent probe provides longer imaging times of caspases than commercial products. The probe proved the stability of the luminescence signal inside cells for more than 14 days.
In recent decades, research scientists, molecular biologists, and pharmacologists have placed a strong emphasis on cutting-edge nanostructured materials technologies to increase medicine delivery to the central nervous system (CNS). The application of nanoscience for the treatment of neurodegenerative diseases (NDs) such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), Huntington's disease (HD), brain cancer, and hemorrhage has the potential to transform care. Multiple studies have indicated that nanomaterials can be used to successfully treat CNS disorders in the case of neurodegeneration. Nanomedicine development for the cure of degenerative and inflammatory diseases of the nervous system is critical. Nanoparticles may act as a drug transporter that can precisely target sick brain sub-regions, boosting therapy success. It is important to develop strategies that can penetrate the blood-brain barrier (BBB) and improve the effectiveness of medications. One of the probable tactics is the use of different nanoscale materials. These nano-based pharmaceuticals offer low toxicity, tailored delivery, high stability, and drug loading capacity. They may also increase therapeutic effectiveness. A few examples of the many different kinds and forms of nanomaterials that have been widely employed to treat neurological diseases include quantum dots, dendrimers, metallic nanoparticles, polymeric nanoparticles, carbon nanotubes, liposomes, and micelles. These unique qualities, including sensitivity, selectivity, and ability to traverse the BBB when employed in nano-sized particles, make these nanoparticles useful for imaging studies and treatment of NDs. Multifunctional nanoparticles carrying pharmacological medications serve two purposes: they improve medication distribution while also enabling cell dynamics imaging and pharmacokinetic study. However, because of the potential for wide-ranging clinical implications, safety concerns persist, limiting any potential for translation. The evidence for using nanotechnology to create drug delivery systems that could pass across the BBB and deliver therapeutic chemicals to CNS was examined in this study.
- Publication type
- Journal Article MeSH
- Review MeSH
This study illustrates the synthesis of functionalized carbon quantum dots (CQDs) by the one-pot pyrolysis method. The functionalization agent used in CQD synthesis was poly l- lysine (PLL). Various physicochemical techniques were employed to confirm the successful formation of PLLCQD including High resolution transmission electron microscopy (HR-TEM), UV-Vis spectroscopy, fluorescence spectroscopy; Atomic force microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS) and X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The size of PLLCQD was confirmed by HRTEM and AFM. The synthesized PLLCQD shows bright blue fluorescence and has a quantum yield of 19.35%. The highest emission band was observed at 471nm when excited to 370nm. The prepared PLLCQD exhibited excellent antibacterial activity against Escherichia coli and Staphylococcus aureus with inhibition zone 7-20 mm. The concentrations of 0.9 to 0.1gmL-1 were studied to determine minimum inhibitory concentration (MIC) by the agar well diffusion assay method. MIC of 0.2gml -1 concentration of PLLCQD is achieved. The anti-angiogenic activity of PLLCQD was determined using (Chick Chorioallantoic Membrane) CAM assay. CAM assay is a reliable in -vivo model to study angiogenesis also; many stimulators and inhibitors have been examined by this method. This study proves higher antibacterial efficiency of PLLCQD over non functionalized CQD. PLLCQD was successfully employed in bio-imaging of the bacterial cell through fluorescence microscopy. Further, PLLCQD displayed cytotoxic effect on endothelial cells and inhibited blood vessel formation in the CAM model.
The application of quantum dots (QDs) for detecting and treating various types of coronaviruses is very promising, as their low toxicity and high surface performance make them superior among other nanomaterials; in conjugation with fluorescent probes they are promising semiconductor nanomaterials for the detection of various cellular processes and viral infections. In view of the successful results for inhibiting SARS-CoV-2, functional QDs could serve eminent role in the growth of safe nanotherapy for the cure of viral infections in the near future; their large surface areas help bind numerous molecules post-synthetically. Functionalized QDs with high functionality, targeted selectivity, stability and less cytotoxicity can be employed for highly sensitive co-delivery and imaging/diagnosis. Besides, due to the importance of safety and toxicity issues, QDs prepared from plant sources (e.g. curcumin) are much more attractive, as they provide good biocompatibility and low toxicity. In this review, the recent developments pertaining to the diagnostic and inhibitory potentials of QDs against SARS-CoV-2 are deliberated including important challenges and future outlooks. © 2022 Society of Chemical Industry (SCI).
- Publication type
- Journal Article MeSH
- Review MeSH
