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Nanoparticles for biomedical applications. Jana Drbohlavova

Nanoparticles for biomedical applications Jana Drbohlavova Ref. NAZARENUS, M. et al. Beilstein Journal of Nanotechnology, 2014, vol. 5, pp Nanoparticles Fullerenes Carbon nanotubes Silver Gold
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Nanoparticles for biomedical applications Jana Drbohlavova Ref. NAZARENUS, M. et al. Beilstein Journal of Nanotechnology, 2014, vol. 5, pp Nanoparticles Fullerenes Carbon nanotubes Silver Gold Titania Cell membrane Fe 3 O 4 What new? Advance in chemical colloidal synthesis - bottom-up approach Hybrid structures combining at least two properties: magnetic, fluorescence or plazmonic Safety? Regulations, standards, and guidance for nanomaterials NANO.GOV. Standards for Nanotechnology. RTI-INTERNATIONAL. STANDARDS AND GUIDANCE. ce.aspx BIGALL, N. C. et al. Nano Today, 2012, vol. 7, no. 4, pp ISSN LU, Y. J. et al. Acs Applied Materials & Interfaces, 2015, vol. 7, no. 9, pp ISSN LEE, M. et al. Rsc Advances, 2015, vol. 5, no. 27, pp ISSN Medical application Quantum dots Nucles Specific protein Microtubules Mitochondria Actin filament Quantum dots Nanocrystals or atom clusters general size of 2 20 nm Quantum confinement effect Metals: Ni, Co, Pt, Au Semiconductors II-VI (CdTe, CdSe, CdS, ZnSe, ZnS, PbS, PbSe, PbTe, SnTe), Semiconductors III-V (InP, GaAs, ) Intensive luminescence The key properties Highly fluorescence probes for detection of biologically active compounds Higher sensitivity, longer stability, good biocompatibility, minimally invasive Long life-time: ns Absorption at lower wavelength Broad absorption spectrum Core/shell Higher quantum yield and stability: Hinder non-specific interaction with macromolecules aggregation and change of fluorescence Size and chemical composition: CdS = blue emmision CdSe = VIS emmision CdTe = red up to NIR PbS, PbSe = NIR Ref. In vivo application Characterization of biomolecules and biological system in organism Vascular imaging Imaging of tumours Biodistribution and tracking of QDs Future: monitoring of tranplanted cells! MRI is not able to distinguish between original and transplanted cells? How to monitor the movement of cells and their differentiation in real time? phagocytosis or connec on with cell surface via interac on of an bodyreceptor Cell is transplanted into animal or bacteria bacterial screening Organic fluorofor and chemiluminescence probes are limited with wavelenght of emission ( 650 nm) QDs: tunable emission (size, composition) Biologic imaging: In vivo imaging ( nm) low absorption by tissues and minimal scaterring NIR emission: CdTe, CdTeSe, InPAs, PbS, PbSe Direct transport of QDs: intravenous or subcutaneously into blood interaction with plasma, blood cell and vascular endotelium How to get inside? Nonspecific pinocytosis, microinjection, peptide induced transport, In vivo imaging (a) fibroblast cells (b) QDs with antibody: live cell of breast cancer (c) QDs with Tat peptide: delivery in live mammalian cells (d) frozen tissue Vascular imaging Fluorescence Intravenous delivered QDs can monitor: morphologic abnormalities biodistribution of nanoparticles for drug delivery Dynamic of blood flow Subcutaneously delivered QDs can: Mapping of lymphatic drainage area and sentinel lymph nodes? transport mechanism related to diseases (e.g. tumour metastasis) Clinical practice: improvement of diagnosis, more effective and less invasive removal of tumour and lymphatic nodes Vascular imaging We do not need to: monitor extravasation, organ selectivity, uptake by cell, nonspecific binging to target,.. Useful in cardiovascular and lymphatic angiography We need to ensure long circulation, higher stability under physiologic conditions Synthesis of QDs with biodegradable coating which protect the core hinder QDs filtra on by kidney or uptake by reticuloendothelial system (RES) Solu on: polymer coa ng (PEG, methoxy-peg), phospholipid micelles FRET FRET Fluorescence resonance energy transfer from donor to acceptor if the distance between them is lower than critical radius = Increase of emission intensity of acceptor Monitoring of conformal change of proteins Monitoring of protein interaction Study of enzymatic activity FRET Green fluorescent dye Cyanine 3 Red fluorescent dye Alexafluor 647 Self-ordered CdSe/ZnS QDs Quantum confinement effect Radius of nanoparticle is below: Bohr radius of electron a e Bohr radius of hole a h Bohr radius of exciton a exc e.g. InAs: 36 nm, CuCl: 0.7 nm Band gap energy determines the emission wavelength ( nm) Bigger QDs: smaller E bg red light Smaller QDs: higher E bg blue light Fluorescence Photon absorption transfer from S 0 to S 1 Fast vibrational relaxation S 1 ( s) Fluorescent transfer to S 0 Vibrational relaxation S 0 Ref. of water soluble QDS Good reproducibility, low toxicity, low-cost preparation Quantum yield below 30 % of insoluble QDs followed by QDs synthesis Quantum yield % precursors: Chalkogenides of metals (sulphides, selenides, tellurides) Organometals (dimethyl cadmium, diethyl zinc) Metal oxides (CdO) Metal salts (stearates, acetates, nitrates) Chalcogenes (S, Se, Te) Better efficiency, lower toxicity, higher reproducibility Better stability in aqueous environment, better biocompatibility Water solluble QDs Long reaction (hours, days) Salts of heavy metals (Zn, Cd, ) Chalcogenes comercial (Na 2 TeO 3 ) = reaction in air atmosphere; or freshly prepared = reaction in inert atmosphere Surface modificatin with thiol ligands: reduced glutathione, thioglycolic acid, mercaptoacetic acid, Synthesis in Much faster reaction in reverse micelles Simple, cheap, reproducible Control of size and shape Insoluble QDs Reactants Coordinationg organic solvent Trioctylfosfin oxide (TOPO) Trioctylfosfine (TOP) Hexadecylamine (HDA) 300 C Insoluble QDs Ligand exchange Amphiphilic diblock and triblock copolymers and phospholipids Polymer layer of SiO 2 Coordination ligands hinder the crystal growth and aggregation due to Ostwald ripening Functionalization The crucial step! Minimal toxicity (Cd, Pb)! Hinder the creation of ROS =reactive oxygen species: OH, O 2 - a 1 O 2 irreversible damage of NK, cells, tissues Biocompatibility (-NH 2, -COOH, ) e.g.. glutathione QDs toxicity High suface area, high activity Size, concentration, charge Bioactivity of functional layer Oxidative, photolytic and mechanical stability Bioconjugation with proteins, nucleic acids, peptides, biomolecules,... Strategy: highly specific interation e.g. biotin-avidin (streptavidin, neutravidin) NF-CZ07-ICP : Formation of research surrounding for young researchers in the field of advanced materials for catalysis and bioapplications Thanks for your attention Many thanks to JIC which provided us this room for free And many thanks to Hanka Coufalová for administrative work and management
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