scholarly journals Fabrication of polyethylene terephthalate (PET) nanoparticles with fluorescent tracers for studies in mammalian cells

2021 ◽  
Author(s):  
Leah M. Johnson ◽  
Jeffrey B. Mecham ◽  
Sai Archana Krovi ◽  
Maria M. Moreno Caffaro ◽  
Shyam Aravamudhan ◽  
...  
Keyword(s):  
Polyethylene Terephthalate ◽  
Mammalian Cells ◽  
Hydrodynamic Diameter ◽  
Fluorescent Nanoparticles ◽  
Fluorescent Tracers ◽  
Bottom Up

Fluorescent nanoparticles (NPs) comprising polyethylene terephthalate (PET) with a hydrodynamic diameter of 158 ± 2 nm were synthesized in a bottom-up approach.

scholarly journals Liposomes Composed by Membrane Lipid Extracts from Macrophage Cell Line as a Delivery of the Trypanocidal N,N’-Squaramide 17 towards Trypanosoma cruzi

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5505
Author(s):  
Christian Rafael Quijia ◽  
Cínthia Caetano Bonatto ◽  
Luciano Paulino Silva ◽  
Milene Aparecida Andrade ◽  
Clenia Santos Azevedo ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Mammalian Cells ◽  
Entrapment Efficiency ◽  
Membrane Lipid ◽  
Raw 264.7 Cells ◽  
Hydrodynamic Diameter ◽  
Raw 264.7 ◽  
Low Cytotoxicity

Chagas is a neglected tropical disease caused by Trypanosoma cruzi, and affects about 25 million people worldwide. N, N’-Squaramide 17 (S) is a trypanocidal compound with relevant in vivo effectiveness. Here, we produced, characterized, and evaluated cytotoxic and trypanocidal effects of macrophage-mimetic liposomes from lipids extracted of RAW 264.7 cells to release S. As results, the average hydrodynamic diameter and Zeta potential of mimetic lipid membranes containing S (MLS) was 196.5 ± 11 nm and −61.43 ± 2.3 mV, respectively. Drug entrapment efficiency was 73.35% ± 2.05%. After a 72 h treatment, MLS was observed to be active against epimastigotes in vitro (IC50 = 15.85 ± 4.82 μM) and intracellular amastigotes (IC50 = 24.92 ± 4.80 μM). Also, it induced low cytotoxicity with CC50 of 1199.50 ± 1.22 μM towards VERO cells and of 1973.97 ± 5.98 μM in RAW 264.7. MLS also induced fissures in parasite membrane with a diameter of approximately 200 nm in epimastigotes. MLS showed low cytotoxicity in mammalian cells and high trypanocidal activity revealing this nanostructure a promising candidate for the development of Chagas disease treatment.

Miniaturized sample preparation on a digital microfluidics device for sensitive bottom-up microproteomics of mammalian cells using magnetic beads and mass spectrometry-compatible surfactants

Lab on a Chip ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 3490-3498 ◽  
Author(s):  
Jan Leipert ◽  
Andreas Tholey
Keyword(s):  
Mass Spectrometry ◽  
Sample Preparation ◽  
Mammalian Cells ◽  
Magnetic Beads ◽  
Digital Microfluidics ◽  
Bottom Up ◽  
Polymer Surfactants

The combination of digital microfluidics and magnetic beads for removal of polymer surfactants enables sensitive LC-MS-based microproteomics analyses down to 100 mammalian cells.

scholarly journals Polyfluorene-Based Multicolor Fluorescent Nanoparticles Activated by Temperature for Bioimaging and Drug Delivery

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1485 ◽  
Author(s):  
Marta Rubio-Camacho ◽  
Yolanda Alacid ◽  
Ricardo Mallavia ◽  
María José Martínez-Tomé ◽  
C. Reyes Mateo
Keyword(s):  
Mammalian Cells ◽  
Photophysical Properties ◽  
Drug Carriers ◽  
Fluorescent Nanoparticles ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Hydrophilic Drug ◽  
Thermosensitive Liposomes ◽  
Size And Morphology ◽  
The Stability

Multifunctional nanoparticles have been attracting growing attention in recent years because of their capability to integrate materials with different features in one entity, which leads them to be considered as the next generation of nanomedicine. In this work, we have taken advantage of the interesting properties of conjugated polyelectrolytes to develop multicolor fluorescent nanoparticles with integrating imaging and therapeutic functionalities. With this end, thermosensitive liposomes were coated with three recently synthesized polyfluorenes: copoly-((9,9-bis(6′-N,N,N-trimethylammonium)hexyl)-2,7-(fluorene)-alt-1,4-(phenylene)) bromide (HTMA-PFP), copoly-((9,9-bis(6′-N,N,N-trimethylammonium)hexyl)-2,7-(fluorene)-alt-4,7-(2- (phenyl)benzo(d) (1,2,3) triazole)) bromide (HTMA-PFBT) and copoly-((9,9-bis(6′-N,N,N- trimethylammonium)hexyl)-2,7-(fluorene)-alt-1,4-(naphtho(2,3c)-1,2,5-thiadiazole)) bromide (HTMA-PFNT), in order to obtain blue, green and red fluorescent drug carriers, respectively. The stability, size and morphology of the nanoparticles, as well as their thermotropic behavior and photophysical properties, have been characterized by Dynamic Light Scattering (DLS), Zeta Potential, transmission electron microscope (TEM) analysis and fluorescence spectroscopy. In addition, the suitability of the nanostructures to carry and release their contents when triggered by hyperthermia has been explored by using carboxyfluorescein as a hydrophilic drug model. Finally, preliminary experiments with mammalian cells demonstrate the capability of the nanoparticles to mark and visualize cells with different colors, evidencing their potential use for imaging and therapeutic applications.

Preparation of Highly Monodisperse Polymeric Particles Incorporating Polymerizable Perylene-Bisimide Fluorophore

2010 ◽  
Vol 93-94 ◽  
pp. 521-524
Author(s):  
Phimwipha Piyakulawat ◽  
Duangporn Polpanich ◽  
Raweewan Thiramanas ◽  
Udom Asawapirom
Keyword(s):  
Acrylic Acid ◽  
Condensation Reaction ◽  
Miniemulsion Polymerization ◽  
Hydrodynamic Diameter ◽  
Fluorescent Nanoparticles ◽  
Tetracarboxylic Acid ◽  
Perylene Bisimide ◽  
Polymeric Particles ◽  
Ft Ir ◽  
Allyl Amine

In this work, the yellow emitted perylene-bisimide dye with polymerizable functional groups was synthesized by condensation reaction of perylene tetracarboxylic acid dianhydride and allyl amine. The resulting polymerizable fluorophore was characterized in terms of structure with NMR and FT-IR, the absorption and emission properties by using UV-Vis and fluorescence spectroscopy, respectively. Afterwards, the reactive polymerizable fluorophore was incorporated into the polymer nanoparticle by copolymerization with styrene and acrylic acid monomers via miniemulsion polymerization. The obtained fluorescent nanoparticles was stable and showed a highly monodisperse size distribution with hydrodynamic diameter of 91.8±0.4 nm.

scholarly journals Water soluble, red emitting, carbon nanoparticles stimulate 3D cell invasion via clathrin-mediated endocytic uptake

2021 ◽  
Author(s):  
Udisha Singh ◽  
Aditya Guduru ◽  
Shanka Walia ◽  
Payal Vaswani ◽  
Sameer V Dalvi ◽  
...  
Keyword(s):  
Cell Invasion ◽  
Mammalian Cells ◽  
Diphenyl Ether ◽  
Water Soluble ◽  
Fluorescent Nanoparticles ◽  
Organic Substrates ◽  
Cellular Processes ◽  
New Class ◽  
Intracellular Drug Delivery ◽  
Average Size

Bright, fluorescent nanoparticles with excitation and emission towards the red end of the spectrum are highly desirable in the field of bioimaging. We present here a new class of organic carbon-based nanoparticles (CNPs) with robust quantum yield and fluorescence towards the red region of the spectrum. Using organic substrates like para-phenylenediamine (PPDA) dispersed in diphenyl ether and reflux conditions, we achieved scalable amounts of CNPs of the average size of 25 nm. These CNPs were readily uptaken by different mammalian cells, and we show that they prefer clathrin-mediated endocytosis for their cellular entry route. Not only can these CNPs be specifically uptaken in cells, but they also stimulate cellular processes like cell invasion from 3D spheroid models. These new class of CNPs, which have sizes similar to proteinaceous ligands, hold immense potential for their surface functionalization, whereby they could be explored as promising bioimaging agents for biomedical imaging and intracellular drug delivery.

scholarly journals A Comparative Study of Top-Down and Bottom-Up Carbon Nanodots and Their Interaction with Mercury Ions

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1265
Author(s):  
Federico Bruno ◽  
Alice Sciortino ◽  
Gianpiero Buscarino ◽  
Maria Laura Soriano ◽  
Ángel Ríos ◽  
...  
Keyword(s):  
Optical Properties ◽  
Carbon Dots ◽  
Carbon Nanodots ◽  
Fluorescent Nanoparticles ◽  
Mercury Ions ◽  
Top Down ◽  
Structural And Optical Properties ◽  
Bottom Up ◽  
Interaction Sites ◽  
Sensing Applications

We report a study of carbon dots produced via bottom-up and top-down routes, carried out through a multi-technique approach based on steady-state fluorescence and absorption, time-resolved fluorescence spectroscopy, Raman spectroscopy, infrared spectroscopy, and atomic force microscopy. Our study focuses on a side-to-side comparison of the fundamental structural and optical properties of the two families of fluorescent nanoparticles, and on their interaction pathways with mercury ions, which we use as a probe of surface emissive chromophores. Comparison between the two families of carbon dots, and between carbon dots subjected to different functionalization procedures, readily identifies a few key structural and optical properties apparently common to all types of carbon dots, but also highlights some critical differences in the optical response and in the microscopic mechanism responsible of the fluorescence. The results also provide suggestions on the most likely interaction sites of mercury ions at the surface of carbon dots and reveal details on mercury-induced fluorescence quenching that can be practically exploited to optimize sensing applications of carbon dots.

scholarly journals A bottom-up approach for the de novo design of functional proteins

2020 ◽  
Author(s):  
Che Yang ◽  
Fabian Sesterhenn ◽  
Jaume Bonet ◽  
Eva van Aalen ◽  
Leo Scheller ◽  
...  
Keyword(s):  
Protein Design ◽  
Mammalian Cells ◽  
De Novo ◽  
Protein Structures ◽  
Functional Protein ◽  
Regular Secondary Structure ◽  
Bottom Up ◽  
Binding Motifs ◽  
Wide Range ◽  
Novel Protein

AbstractDe novo protein design has enabled the creation of novel protein structures. To design novel functional proteins, state-of-the-art approaches use natural proteins or first design protein scaffolds that subsequently serve as templates for the transplantation of functional motifs. In these approaches, the templates are function-agnostic and motifs have been limited to those with regular secondary structure. Here, we present a bottom-up approach to build de novo proteins tailored to structurally complex functional motifs. We applied a bottom-up strategy to design scaffolds for four different binding motifs, including one bi-functionalized protein with two motifs. The de novo proteins were functional as biosensors to quantify epitope-specific antibody responses and as orthogonal ligands to activate a signaling pathway in engineered mammalian cells. Altogether, we present a versatile strategy for the bottom-up design of functional proteins, applicable to a wide range of functional protein design challenges.

scholarly journals Fluorescent Phthalocyanine-Encapsulated Bovine Serum Albumin Nanoparticles: Their Deployment as Therapeutic Agents in the NIR Region

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4679
Author(s):  
Raluca Borlan ◽  
Daria Stoia ◽  
Luiza Gaina ◽  
Andreea Campu ◽  
Gabriel Marc ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Biomedical Applications ◽  
Therapeutic Agents ◽  
Hydrodynamic Diameter ◽  
Fluorescent Nanoparticles ◽  
Docking Simulations ◽  
Viability Assay ◽  
Conversion Performance

In recent times, researchers have aimed for new strategies to combat cancer by the implementation of nanotechnologies in biomedical applications. This work focuses on developing protein-based nanoparticles loaded with a newly synthesized NIR emitting and absorbing phthalocyanine dye, with photodynamic and photothermal properties. More precisely, we synthesized highly reproducible bovine serum albumin-based nanoparticles (75% particle yield) through a two-step protocol and successfully encapsulated the NIR active photosensitizer agent, achieving a good loading efficiency of 91%. Making use of molecular docking simulations, we confirm that the NIR photosensitizer is well protected within the nanoparticles, docked in site I of the albumin molecule. Encouraging results were obtained for our nanoparticles towards biomedical use, thanks to their negatively charged surface (−13.6 ± 0.5 mV) and hydrodynamic diameter (25.06 ± 0.62 nm), favorable for benefitting from the enhanced permeability and retention effect; moreover, the MTT viability assay upholds the good biocompatibility of our NIR active nanoparticles. Finally, upon irradiation with an NIR 785 nm laser, the dual phototherapeutic effect of our NIR fluorescent nanoparticles was highlighted by their excellent light-to-heat conversion performance (photothermal conversion efficiency 20%) and good photothermal and size stability, supporting their further implementation as fluorescent therapeutic agents in biomedical applications.

Ultrastructural Alterations in Hela Cells Induced by Spider Venom

1967 ◽  
Vol 25 ◽  
pp. 20-21
Author(s):  
Dale E. McClendon ◽  
Paul N. Morgan ◽  
Bernard L. Soloff
Keyword(s):  
Growth Medium ◽  
Mammalian Cells ◽  
Carcinoma Cells ◽  
Venom Protein ◽  
Sterile Saline ◽  
Carbon Coated ◽  
Available Information ◽  
Loxosceles Reclusa ◽  
Essential Growth ◽  
Solution Cultures

It has been observed that minute amounts of venom from the brown recluse spider, Loxosceles reclusa, are capable of producing cytotoxic changes in cultures of certain mammalian cells (Morgan and Felton, 1965). Since there is little available information concerning the effect of venoms on susceptible cells, we have attempted to characterize, at the electron microscope level, the cytotoxic changes produced by the venom of this spider.Cultures of human epithelial carcinoma cells, strain HeLa, were initiated on sterile, carbon coated coverslips contained in Leighton tubes. Each culture was seeded with approximately 1x105 cells contained in 1.5 ml of a modified Eagle's minimum essential growth medium prepared in Hank's balanced salt solution. Cultures were incubated at 36° C. for three days prior to the addition of venom. The venom was collected from female brown recluse spiders and diluted in sterile saline. Protein determinations on the venom-were made according to the spectrophotometric method of Waddell (1956). Approximately 10 μg venom protein per ml of fresh medium was added to each culture after discarding the old growth medium. Control cultures were treated similarly, except that no venom was added. All cultures were reincubated at 36° C.

Use of Uranium-Labeled Antibodies for Electron Microscopic Localization of Various Antigens in Mammalian Cells

1967 ◽  
Vol 25 ◽  
pp. 136-137
Author(s):  
J. P. Petrali ◽  
E. J. Donati ◽  
L. A. Sternberger
Keyword(s):  
Endoplasmic Reticulum ◽  
Hela Cells ◽  
Mammalian Cells ◽  
Specific Antiserum ◽  
Electron Microscopic ◽  
E Coli ◽  
Cytoplasmic Membranes ◽  
Viral Progeny ◽  
Ultrathin Sections ◽  
Electron Microscopic Localization

Specific contrast is conferred to subcellular antigen by applying purified antibodies, exhaustively labeled with uranium under immunospecific protection, to ultrathin sections. Use of Seligman’s principle of bridging osmium to metal via thiocarbohydrazide (TCH) intensifies specific contrast. Ultrathin sections of osmium-fixed materials were stained on the grid by application of 1) thiosemicarbazide (TSC), 2) unlabeled specific antiserum, 3) uranium-labeled anti-antibody and 4) TCH followed by reosmication. Antigens to be localized consisted of vaccinia antigen in infected HeLa cells, lysozyme in monocytes of patients with monocytic or monomyelocytic leukemia, and fibrinogen in the platelets of these leukemic patients. Control sections were stained with non-specific antiserum (E. coli).In the vaccinia-HeLa system, antigen was localized from 1 to 3 hours following infection, and was confined to degrading virus, the inner walls of numerous organelles, and other structures in cytoplasmic foci. Surrounding architecture and cellular mitochondria were unstained. 8 to 14 hours after infection, antigen was localized on the outer walls of the viral progeny, on cytoplasmic membranes, and free in the cytoplasm. Staining of endoplasmic reticulum was intense and focal early, and weak and diffuse late in infection.

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