A New Water-Soluble Thermosensitive Star-Like Copolymer as a Promising Carrier of the Chemotherapeutic Drug Doxorubicin

A new water-soluble thermosensitive star-like copolymer, dextran-graft-poly-N-iso-propilacrylamide (D-g-PNIPAM), was created and characterized by various techniques (size-exclusion chromatography, differential scanning calorimetry, Fourier-transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) spectroscopy). The viability of cancer cell lines (human transformed cervix epithelial cells, HeLa) as a model for cancer cells was studied using MTT and Live/Dead assays after incubation with a D-g-PNIPAM copolymer as a carrier for the drug doxorubicin (Dox) as well as a D-g-PNIPAM + Dox mixture as a function of the concentration. FTIR spectroscopy clearly indicated the complex formation of Dox with the D-g-PNIPAM copolymer. The size distribution of particles in Hank’s solution was determined by the DLS technique at different temperatures. The in vitro uptake of the studied D-g-PNIPAM + Dox nanoparticles into cancer cells was demonstrated by confocal laser scanning microscopy. It was found that D-g-PNIPAM + Dox nanoparticles in contrast to Dox alone showed higher toxicity toward cancer cells. All of the aforementioned facts indicate a possibility of further preclinical studies of the water-soluble D-g-PNIPAM particles’ behavior in animal tumor models in vivo as promising carriers of anticancer agents.

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Effect of dissolution rate and subsequent ion release on cytocompatibility properties of borophosphate glasses

Biomedical glasses ◽

10.1515/bglass-2019-0008 ◽

2019 ◽

Vol 5 (1) ◽

pp. 85-97

Author(s):

Nusrat Sharmin ◽

Mohammad S. Hasan ◽

Md. Towhidul Islam ◽

Chengheng Pang ◽

Fu Gu ◽

...

Keyword(s):

Dissolution Rate ◽

Laser Scanning ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Ion Release ◽

Scanning Calorimetry ◽

Cell Culture Study ◽

Borophosphate Glasses ◽

Mg63 Cells

AbstractPresent work explores the relationship between the composition, dissolution rate, ion release and cytocompatibility of a series of borophosphate glasses. While, the base glass was selected to be 40mol%P2O5-16mol%CaO-24mol%MgO-20mol%Na2O, three B2O3 modified glass compositions were formulated by replacing Na2O with 1, 5 and 10 mol% B2O3. Ion release study was conducted using inductively coupled plasma atomic emission spectroscopy (ICP-AES). The thermal scans of the glasses as determined by differential scanning calorimetry (DSC) revealed an increment in the thermal properties with increasing B2O3 content in the glasses. On the other hand, the dissolution rate of the glasses decreased with increasing B2O3 content. To identify the effect of boron ion release on the cytocompatibility properties of the glasses, MG63 cells were cultured on the surface of the glass discs. The in vitro cell culture study suggested that glasses with 5 mol% B2O3 (P40B5) showed better cell proliferation and metabolic activity as compares to the glasses with 10 mol% (P40B10) or with no B2O3 (P40B0). The confocal laser scanning microscopy (CLSM) images of live/dead stained MG63 cells attached to the surface of the glasses also revealed that the number of dead cells attached to P40B5 glasses were significantly lower than both P40B0 and P40B10 glasses.

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Synthesis and in vitro biochemical evaluation of oxime bond-linked daunorubicin–GnRH-III conjugates developed for targeted drug delivery

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.14.64 ◽

2018 ◽

Vol 14 ◽

pp. 756-771 ◽

Cited By ~ 8

Author(s):

Sabine Schuster ◽

Beáta Biri-Kovács ◽

Bálint Szeder ◽

Viktor Farkas ◽

László Buday ◽

...

Keyword(s):

Antitumor Activity ◽

Cancer Cells ◽

Cellular Uptake ◽

Laser Scanning ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Dependent Manner ◽

Binding Studies ◽

Gnrh Receptors

Gonadotropin releasing hormone-III (GnRH-III), a native isoform of the human GnRH isolated from sea lamprey, specifically binds to GnRH receptors on cancer cells enabling its application as targeting moieties for anticancer drugs. Recently, we reported on the identification of a novel daunorubicin–GnRH-III conjugate (GnRH-III–[4Lys(Bu), 8Lys(Dau=Aoa)] with efficient in vitro and in vivo antitumor activity. To get a deeper insight into the mechanism of action of our lead compound, the cellular uptake was followed by confocal laser scanning microscopy. Hereby, the drug daunorubicin could be visualized in different subcellular compartments by following the localization of the drug in a time-dependent manner. Colocalization studies were carried out to prove the presence of the drug in lysosomes (early stage) and on its site of action (nuclei after 10 min). Additional flow cytometry studies demonstrated that the cellular uptake of the bioconjugate was inhibited in the presence of the competitive ligand triptorelin indicating a receptor-mediated pathway. For comparative purpose, six novel daunorubicin–GnRH-III bioconjugates have been synthesized and biochemically characterized in which 6Asp was replaced by D-Asp, D-Glu and D-Trp. In addition to the analysis of the in vitro cytostatic effect and cellular uptake, receptor binding studies with 125I-triptorelin as radiotracer and degradation of the GnRH-III conjugates in the presence of rat liver lysosomal homogenate have been performed. All derivatives showed high binding affinities to GnRH receptors and displayed in vitro cytostatic effects on HT-29 and MCF-7 cancer cells with IC50 values in a low micromolar range. Moreover, we found that the release of the active drug metabolite and the cellular uptake of the bioconjugates were strongly affected by the amino acid exchange which in turn had an impact on the antitumor activity of the bioconjugates.

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Effects of cigarette smoking on the growth of Streptococcus mutans biofilms: an in vitro study

10.21203/rs.3.rs-221658/v1 ◽

2021 ◽

Author(s):

Ye Han

Keyword(s):

Treatment Group ◽

Cigarette Smoking ◽

Streptococcus Mutans ◽

Laser Scanning ◽

Water Soluble ◽

Laser Scanning Microscopy ◽

Extracellular Polysaccharides ◽

Confocal Laser ◽

Control Group

Abstract This study aimed to investigate the differences in growth and virulence (EPSs and acidogenicity) of Streptococcus mutans biofilms (S. mutans) according to the different times of cigarette smoking (CS) treatment. S. mutans biofilms (74-hour-old) were formed on saliva-coated hydroxyapatite disks. The biofilms were treated with CS at different times per day (one time, three times, and six times/day). The control group did not receive CS treatment. Acidogenicity, dry weight, colony-forming units, water-soluble/insoluble extracellular polysaccharides, and intracellular polysaccharides were analyzed and confocal laser scanning microscopy images were obtained of the 74-h-old biofilms. The 74-h-old biofilms on sHA discs in the 6 times/day CS treatment group showed the lowest biofilm accumulation and extracellular polysaccharide amount compared with the control group and other CS treatment groups. In the CLSM study, the biofilms in the six times/day CS treatment group also showed the lowest bacterial count (live and dead cells) and EPS biovolume. CS has an obvious inhibition on the growth of S. mutans biofilms, the degree of inhibition is proportional to the number of CS treatments.

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A Novel Solid Nanocrystals Self-Stabilized Pickering Emulsion Prepared by Spray-Drying with Hydroxypropyl-β-cyclodextrin as Carriers

Molecules ◽

10.3390/molecules26061809 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1809

Author(s):

Jifen Zhang ◽

Yanhua Wang ◽

Jirui Wang ◽

Tao Yi

Keyword(s):

Spray Drying ◽

Laser Scanning ◽

Pickering Emulsion ◽

Water Soluble ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Poorly Soluble Drugs ◽

Significant Difference ◽

Poorly Soluble

A drug nanocrystals self-stabilized Pickering emulsion (NSSPE) with a unique composition and microstructure has been proven to significantly increase the bioavailability of poorly soluble drugs. This study aimed to develop a new solid NSSPE of puerarin preserving the original microstructure of NSSPE by spray-drying. A series of water-soluble solid carriers were compared and then Box-Behnken design was used to optimize the parameters of spray-drying. The drug release and stability of the optimized solid NSSPE in vitro were also investigated. The results showed that hydroxypropyl-β-cyclodextrin (HP-β-CD), rather than solid carriers commonly used in solidification of traditional Pickering emulsions, was suitable for the solid NSSPE to retain the original appearance and size of emulsion droplets after reconstitution. The amount of HP-β-CD had more influences on the solid NSSPE than the feed rate and the inlet air temperature. Fluorescence microscopy, confocal laser scanning microscopy and scanning electron microscopy showed that the reconstituted emulsion of the solid NSSPE prepared with HP-β-CD had the same core-shell structure with a core of oil and a shell of puerarin nanocrystals as the liquid NSSPE. The particle size of puerarin nanocrystal sand interfacial adsorption rate also did not change significantly. The cumulative amount of released puerarin from the solid NSSPE had no significant difference compared with the liquid NSSPE, which were both significantly higher than that of puerarin crude material. The solid NSSPE was stable for 3 months under the accelerated condition of 75% relative humidity and 40 °C. Thus, it is possible todevelop the solid NSSPE preserving the unique microstructure and the superior properties in vitro of the liquid NSSPE for poorly soluble drugs.

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Synthesis of Water-Soluble Iridium (III)-Containing Nanoparticles for Biological Applications

Journal of Chemistry ◽

10.1155/2015/475602 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7

Author(s):

Huanzhi Hou ◽

Pengfei Sun ◽

Quli Fan ◽

Xiaomei Lu ◽

Cheng Xue ◽

...

Keyword(s):

Self Assembly ◽

Laser Scanning ◽

Morphological Characterization ◽

Fluorescent Imaging ◽

Water Soluble ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Biological Applications

Water-soluble nanoparticles (Ir/PGlc-NP, Ir/β-1,3-glucan-NP) based on water-soluble glycopolymers (PGlc),β-1,3-glucan polysaccharide, and conjugated phosphorescent Ir (III) complexes were successfully synthesized by self-assembly. The obtained nanoparticles have good spherical morphological characterization with a mean diameter of 50 nm measured by TEM. Ir/PGlc-NP and Ir/β-1,3-glucan-NP showed the same emission maxima at 565 nm in aqueous solution and both caused effective apoptosis and death of HepG2 and Hela cells after being irradiated at 445 nm for 30 min in vitro. Fluorescence cellular imaging was conducted by confocal laser scanning microscopy (CLSM) using HepG2 cells as the model cell in which the nanoparticles had successfully entered into the cytoplasm with high brightness. Furthermore, after injecting the nanoparticles into live mice in vivo, the real-time fluorescence imaging as well as the nanoparticles distribution in organs at 24 hours after administration indicated that these nanoparticles can serve as fluorescent imaging contrast for further biological applications.

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Vacuoles Induced in Mammalian Cells by Helicobacter Cytotoxin are Acidic Organelles

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158388 ◽

1990 ◽

Vol 48 (3) ◽

pp. 168-169

Author(s):

M. H. Chestnut ◽

C. E. Catrenich

Keyword(s):

Acridine Orange ◽

Mammalian Cells ◽

Laser Scanning ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Ulcer Disease ◽

Gastroduodenal Disease ◽

H Pylori

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.

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Cephalosporin nitric oxide-donor prodrug DEA-C3D disperses biofilms formed by clinical cystic fibrosis isolates of Pseudomonas aeruginosa

Journal of Antimicrobial Chemotherapy ◽

10.1093/jac/dkz378 ◽

2019 ◽

Vol 75 (1) ◽

pp. 117-125 ◽

Cited By ~ 8

Author(s):

Odel Soren ◽

Ardeshir Rineh ◽

Diogo G Silva ◽

Yuming Cai ◽

Robert P Howlin ◽

...

Keyword(s):

Nitric Oxide ◽

Cystic Fibrosis ◽

Pseudomonas Aeruginosa ◽

Laser Scanning ◽

Laser Scanning Microscopy ◽

Clinical Isolates ◽

Nitric Oxide Donor ◽

Confocal Laser ◽

Broth Microdilution Method

Abstract Objectives The cephalosporin nitric oxide (NO)-donor prodrug DEA-C3D (‘DiEthylAmin-Cephalosporin-3′-Diazeniumdiolate’) has been shown to initiate the dispersal of biofilms formed by the Pseudomonas aeruginosa laboratory strain PAO1. In this study, we investigated whether DEA-C3D disperses biofilms formed by clinical cystic fibrosis (CF) isolates of P. aeruginosa and its effect in combination with two antipseudomonal antibiotics, tobramycin and colistin, in vitro. Methods β-Lactamase-triggered release of NO from DEA-C3D was confirmed using a gas-phase chemiluminescence detector. MICs for P. aeruginosa clinical isolates were determined using the broth microdilution method. A crystal violet staining technique and confocal laser scanning microscopy were used to evaluate the effects of DEA-C3D on P. aeruginosa biofilms alone and in combination with tobramycin and colistin. Results DEA-C3D was confirmed to selectively release NO in response to contact with bacterial β-lactamase. Despite lacking direct, cephalosporin/β-lactam-based antibacterial activity, DEA-C3D was able to disperse biofilms formed by three P. aeruginosa clinical isolates. Confocal microscopy revealed that DEA-C3D in combination with tobramycin produces similar reductions in biofilm to DEA-C3D alone, whereas the combination with colistin causes near complete eradication of P. aeruginosa biofilms in vitro. Conclusions DEA-C3D is effective in dispersing biofilms formed by multiple clinical isolates of P. aeruginosa and could hold promise as a new adjunctive therapy to patients with CF.

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Use of electromagnetic stimulation on an Enterococcus faecalis biofilm on root canal treated teeth in vitro

Scientific Reports ◽

10.1038/s41598-021-87922-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Beatriz H. D. Panariello ◽

Justin K. Kindler ◽

Kenneth J. Spolnik ◽

Ygal Ehrlich ◽

George J. Eckert ◽

...

Keyword(s):

Enterococcus Faecalis ◽

Root Canal ◽

Laser Scanning ◽

Confocal Imaging ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Microscopy Imaging ◽

Electromagnetic Stimulation ◽

Root Canal Disinfection

AbstractRoot canal disinfection is of utmost importance in the success of the treatment, thus, a novel method for achieving root canal disinfection by electromagnetic waves, creating a synergistic reaction via electric and thermal energy, was created. To study electromagnetic stimulation (EMS) for the disinfection of root canal in vitro, single rooted teeth were instrumented with a 45.05 Wave One Gold reciprocating file. Specimens were sterilized and inoculated with Enterococcus faecalis ATCC 29,212, which grew for 15 days to form an established biofilm. Samples were treated with 6% sodium hypochlorite (NaOCl), 1.5% NaOCl 1.5% NaOCl with EMS, 0.9% saline with EMS or 0.9% saline. After treatments, the colony forming units (CFU) was determined. Data was analyzed by Wilcoxon Rank Sums Test (α = 0.05). One sample per group was scored and split for confocal laser scanning microscopy imaging. There was a significant effect with the use of NaOCl with or without EMS versus 0.9% saline with or without EMS (p = 0.012 and 0.003, respectively). CFUs were lower when using 0.9% saline with EMS versus 0.9% saline alone (p = 0.002). Confocal imaging confirmed CFU findings. EMS with saline has an antibiofilm effect against E. faecalis and can potentially be applied for endodontic disinfection.

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Cocktail of carbohydrases from Aspergillus niger: an economical and eco-friendly option for biofilm clearance from biopolymer surfaces

AMB Express ◽

10.1186/s13568-021-01183-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Arashdeep Kaur ◽

Sanjeev Kumar Soni ◽

Shania Vij ◽

Praveen Rishi

Keyword(s):

Aspergillus Niger ◽

Laser Scanning ◽

Statistical Modelling ◽

Laser Scanning Microscopy ◽

Enzyme Treatment ◽

Confocal Laser ◽

Abiotic Surfaces ◽

Enzyme Cocktail ◽

Natural Variant

AbstractBiofilm formation on both biotic and abiotic surfaces accounts for a major factor in spread of antimicrobial resistance. Due to their ubiquitous nature, biofilms are of great concern for environment as well as human health. In the present study, an integrated process for the co-production of a cocktail of carbohydrases from a natural variant of Aspergillus niger was designed. The enzyme cocktail was found to have a noteworthy potential to eradicate/disperse the biofilms of selected pathogens. For application of enzymes as an antibiofilm agent, the enzyme productivities were enhanced by statistical modelling using response surface methodology (RSM). The antibiofilm potential of the enzyme cocktail was studied in terms of (i) in vitro cell dispersal assay (ii) release of reducing sugars from the biofilm polysaccharides (iii) the effect of enzyme treatment on biofilm cells and architecture by confocal laser scanning microscopy (CLSM). Potential of the enzyme cocktail to disrupt/disperse the biofilm of selected pathogens from biopolymer surfaces was also assessed by field emission scanning electron microscopy (FESEM) analysis. Further, their usage in conjunction with antibiotics was assessed and it was inferred from the results that the use of enzyme cocktail augmented the efficacy of the antibiotics. The study thus provides promising insights into the prospect of using multiple carbohydrases for management of heterogeneous biofilms formed in natural and clinical settings.

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Influence of Salt Support Structures on Material Jetted Aluminum Parts

Materials ◽

10.3390/ma14154072 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4072

Author(s):

Benedikt Kirchebner ◽

Maximilian Ploetz ◽

Christoph Rehekampff ◽

Philipp Lechner ◽

Wolfram Volk

Keyword(s):

Molten Salts ◽

Laser Scanning ◽

Water Soluble ◽

Laser Scanning Microscopy ◽

Confocal Laser ◽

Support Structures ◽

Micro Hardness ◽

X Ray ◽

Melting Temperatures ◽

Economic Support

Like most additive manufacturing processes for metals, material jetting processes require support structures in order to attain full 3D capability. The support structures have to be removed in subsequent operations, which increases costs and slows down the manufacturing process. One approach to this issue is the use of water-soluble support structures made from salts that allow a fast and economic support removal. In this paper, we analyze the influence of salt support structures on material jetted aluminum parts. The salt is applied in its molten state, and because molten salts are typically corrosive substances, it is important to investigate the interaction between support and build material. Other characteristic properties of salts are high melting temperatures and low thermal conductivity, which could potentially lead to remelting of already printed structures and might influence the microstructure of aluminum that is printed on top of the salt due to low cooling rates. Three different sample geometries have been examined using optical microscopy, confocal laser scanning microscopy, energy-dispersive X-ray spectroscopy and micro-hardness testing. The results indicate that there is no distinct influence on the process with respect to remelting, micro-hardness and chemical reactions. However, a larger dendrite arm spacing is observed in aluminum that is printed on salt.

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