Phosphate-buffered Saline Buffer Research Articles

Human Dose Assessment of 68Ga-NODAGA-RGD-BBN Heterodimer Peptide based on Animal Data.

Calculation of the absorbed dose in human organs is one of the first steps for developing new radiopharmaceuticals. The aim of this study is to estimate the human absorbed dose of a newly developed 68Ga-NODAGA-RGD-BBN radiolabeled compound. 68Ga-NODAGA-RGD-BBN was prepared by varying different parameters at optimized conditions. The stability of the radiolabeled peptide in phosphate-buffered saline (PBS) and in human serum was evaluated for 120 min. Afterward, the biodistribution of the complex was assessed in normal and tumor-bearing mice, at least for 120 min postinjection. Finally, the human absorbed dose of 68Ga-NODAGA-RGD-BBN was estimated based on mice data using Radiation Dose Assessment Resource and Spark method. 68Ga-NODAGA-RGD-BBN was produced with radiochemical purity of more than 98% (high-performance liquid chromatography/ radio thin layer chromatography (RTLC)) with high stability in PBS buffer and in human serum at least for 2 h. The complex demonstrated high uptake in gastrin-releasing peptide receptor-expressing tumors compared to other nontarget organs. Furthermore, the dose assessment for the complex showed that the kidneys receive the highest absorbed dose in comparison with other organs. The result of this study showed that 68Ga-NODAGA-RGD-BBN is an effective and radiolabeled ligand for tumor detection, however more studies are still needed.

Enhancing Intersystem Crossing by Intermolecular Dimer-Stacking of Cyanine as Photosensitizer for Cancer Therapy

Enhancing Intersystem Crossing by Intermolecular Dimer-Stacking of Cyanine as Photosensitizer for Cancer Therapy

Supramolecular Polymerization Powered by Escherichia coli : Fabricating a Near-Infrared Photothermal Antibacterial Agent in Situ

Supramolecular Polymerization Powered by <i>Escherichia coli</i> : Fabricating a Near-Infrared Photothermal Antibacterial Agent in Situ

Folic Acid-Modified miR-491-5p-Loaded ZIF-8 Nanoparticles Inhibit Castration-Resistant Prostate Cancer by Regulating the Expression of EPHX1.

Epoxide hydrolase 1 (EPHX1) has been reported to be related to the development of several tumors. However, the regulation of castration-resistant prostate cancer (CRPC) development by EPHX1 has not been reported. We used proteomic technology and found that the EPHX1 protein was highly expressed in CRPC tissues and the CRPC cell line C4-2. We performed screening and found that EPHX1 is a direct target of miR-491-5p. High miR-491-5p expression significantly reduced the EPHX1 level in C4-2 cells and inhibited C4-2 cell proliferation and migration. Zeolite imidazolate framework-8 (ZIF-8) has good thermal stability, a simple synthesis method, tumor site stability, and specific acid responsiveness. We synthesized ZIF-8 nanodrug vectors to deliver miR-491-5p into C4-2 cells. After loading miR-491-5p into ZIF-8, we modified the ZIF-8 surface with folic acid (FA) as the target group (FA@ZIF-8). Our synthesized nanodrug carrier showed less cytotoxicity to C4-2 cells even at 200 μg/ml. Modified FA could increase the efficiency of nanomaterial entry into C4-2 cells. FA@miR-491-5p@ZIF-8 could stably release miR-491-5p for a long period in both phosphate-buffered saline (pH 7.4) and acetate buffer (pH 4.8), and miR-491-5p was released faster at the beginning of the experiment in acetate buffer (pH 4.8). FA@miR-491-5p@ZIF-8 significantly reduced C4-2 cell proliferation and migration, and FA@miR-491-5p@ZIF-8 had a better effect than miR-491-5p alone. In vivo, FA@miR-491-5p@ZIF-8 significantly inhibited CRPC growth in nude mice. Overall, we verified that miR-491-4p regulated CRPC development by targeting EPHX1. The drug nanocarrier FA@miR-491-5p@ZIF-8 not only significantly reduced C4-2 CRPC cell proliferation and migration but also significantly inhibited CRPC growth. Our research provides a theoretical basis for treatment and treatment strategies for CRPC.

Saline-polyethylene glycol blends preserve in vitro annulus fibrosus hydration and mechanics: An experimental and finite-element analysis

Precise control of tissue water content is essential for ensuring accurate, repeatable, and physiologically relevant measurements of tissue mechanics and biochemical composition. While previous studies have found that saline and polyethylene glycol (PEG) blends were effective at controlling tendon and ligament hydration levels, this work has yet to be extended to the annulus fibrosus (AF). Thus, the first objective of this study was to determine and validate an optimal buffer solution for targeting and maintaining hydration levels of tissue-level AF specimens in vitro. This was accomplished by measuring the transient swelling behavior of bovine AF specimens in phosphate-buffered saline (PBS) and PEG buffers across a wide range of concentrations. Sub-failure, failure, and post-failure mechanics were measured to determine the relationship between changes in tissue hydration and tensile mechanical response. The effect of each buffer solution on tissue composition was also assessed. The second objective of this study was to assess the feasibility and effectiveness of using multi-phasic finite element models to investigate tissue swelling and mechanical responses in different external buffer solutions.A solution containing 6.25%w/v PBS and 6.25%w/v PEG effectively maintained tissue-level AF specimen hydration at fresh-frozen levels after 18 h in solution. Modulus, failure stress, failure strain, and post-failure toughness of specimens soaked in this solution for 18 h closely matched those of fresh-frozen specimens. In contrast, specimens soaked in 0.9%w/v PBS swelled over 100% after 18 h and exhibited significantly diminished sub-failure and failure properties compared to fresh-frozen controls. The increased cross-sectional area with swelling contributed to but was not sufficient to explain the diminished mechanics of PBS-soaked specimens, suggesting additional sub-tissue scale mechanisms. Computational simulations of these specimens generally agreed with experimental results, highlighting the feasibility and importance of including a fluid-phase description when models aim to provide accurate predictions of biological tissue responses. As numerous previous studies suggest that tissue hydration plays a central role in maintaining proper mechanical and biological function, robust methods for controlling hydration levels are essential as the field advances in probing the relationship between tissue hydration, aging, injury, and disease.

Co-amorphous solids of dasatinib and olanzapine by saccharin with promising physicochemical properties

Two co-amorphous compounds of poorly water-soluble drugs dasatinib (DAS) and olanzapine (OLA) were formed, dasatinib-saccharin (DAS-SAC), and olanzapine-saccharin (OLA-SAC) with saccharin (SAC) as the co-former through liquid assisted grinding method, and at large scale, by rapidly evaporating the solvent (ethanol) from a rota-vapor at 60 °C under vacuum. The co-amorphous solids showed improved dissolution rates in phosphate-buffered saline (PBS, pH 7.2) and glycine-HCl buffer (pH 3.6) at 37 °C compared to the freeform. For example, the dissolution rate of DAS-SAC in PBS in first 10 min was 0.12 mg/mL (30-times faster than DAS) compared to 0.004 mg/mL of DAS. The dissolution rate of OLA-SAC in PBS in 10 min was 1.72 mg/mL and more than OLA (~21 times faster) as opposed to 0.08 mg/mL of OLA. Thermal analysis of the DAS-SAC and OLA-SAC showed single glass transition temperature (Tg) with the onsets of 132.8 °C and 161.7 °C, respectively indicating the amorphous nature of solids. The co-amorphous forms were stable at various temperatures (6 °C, 25 °C and 40 °C) and relative humidity (11%, 75% and dry condition) for up to eight weeks. Importantly, no amorphous forms were able to produce with DAS and OLA through grinding or quick evaporation without the use of SAC.

A Magnetocatalytic Propelled Cobalt–Platinum@Graphene Navigator for Enhanced Tumor Penetration and Theranostics

A Magnetocatalytic Propelled Cobalt–Platinum@Graphene Navigator for Enhanced Tumor Penetration and Theranostics

A Highly Stable Two-Photon Ratiometric Fluorescence Probe for Real-Time Biosensing and Imaging of Nitric Oxide in Brain Tissues and Larval Zebrafish

A Highly Stable Two-Photon Ratiometric Fluorescence Probe for Real-Time Biosensing and Imaging of Nitric Oxide in Brain Tissues and Larval Zebrafish

Comparison of human blood serum DSC profiles in aqueous and PBS buffer solutions

The results of studies of physiological fluids by differential scanning calorimetry (DSC) for the purpose of diagnosis and monitoring of diseases are promising. Before the DSC method is accepted in medical diagnostics, it is worth experimenting with various environmental conditions at the research stage. Among other things, it is important to choose an appropriate solvent to dilute the tested biological fluids. In this work, human blood sera DSC profiles in aqueous and PBS (phosphate-buffered saline) solutions have been compared. Visibility of haptoglobin in the DSC profile of human blood serum is much better in water solution. In addition, contributions from albumin and haptoglobin are well separated in contrast to the PBS serum solutions. The peak or shoulder at about 83 °C which represents contributions from the CH3 domain of immunoglobulin IgG1 and/or transferrin is more clearly visible in PBS solution. The results show that the type of solvent is essential when interpreting the serum DSC profile.

Biomimetic Recognition-Based Bioorthogonal Host–Guest Pairs for Cell Targeting and Tissue Imaging in Living Animals

Biomimetic Recognition-Based Bioorthogonal Host–Guest Pairs for Cell Targeting and Tissue Imaging in Living Animals

Protective Effects of Amino Acids on Plasmid DNA Damage Induced by Therapeutic Carbon Ions.

Radioprotectors with few side effects are useful for carbon-ion therapy, which directly induces clustering damage in DNA. With the aim of finding the most effective radioprotector, we investigated the effects of selected amino acids which might have chemical DNA-repair functions against therapeutic carbon ions. In the current study, we employed five amino acids: tryptophan (Trp), cysteine (Cys), methionine (Met), valine (Val) and alanine (Ala). Samples of supercoiled pBR322 plasmid DNA with a 17 mM amino acid were prepared in TE buffer (10 mM Tris, 1 mM ethylenediaminetetraacetic acid, pH 7.5). Phosphate buffered saline (PBS) was also used in assays of the 0.17 mM amino acid. The samples were irradiated with carbon-ion beams (290 MeV/u) on 6 cm spread-out Bragg peak at the National Institute of Radiological Sciences and Heavy Ion Medical Accelerator in Chiba, Japan. Breaks in the DNA were detected as changes in the plasmids and quantified by subsequent electrophoresis on agarose gels. DNA damage yields and protection factors for each amino acid were calculated as ratios relative to reagent-free controls. Trp and Cys showed radioprotective effects against plasmid DNA damage induced by carbon-ion beam, both in PBS and TE buffer, comparable to those of Met. The double-strand break (DSB) yields and protective effects of Trp were comparable to those of Cys. The yields of both single-strand breaks and DSBs correlated with the scavenging capacity of hydroxyl radicals (rate constant for scavenging hydroxyl radicals multiplied by the amino acid concentration) in bulk solution. These data indicate that the radioprotective effects of amino acids against plasmid DNA damage induced by carbon ions could be explained primarily by the scavenging capacity of hydroxyl radicals. These findings suggest that some amino acids, such as Trp, Cys and Met, have good potential as radioprotectors for preventing DNA damage in normal tissues in carbon-ion therapy.

Loading and Release of Charged and Neutral Fluorescent Dyes into and from Mesoporous Materials: A Key Role for Sensing Applications.

The aim of this study is to determine the efficiency of loading and release of several zwitterionic, neutral, anionic and cationic dyes into/from mesoporous nanoparticles to find the optimum loading and release conditions for their application in detection protocols. The loading is carried out for MCM-41 type silica supports suspended in phosphate-buffered saline (PBS) buffer (pH 7.4) or in acetonitrile, involving the dyes (rhodamine B chloride, rhodamine 101 chloride, rhodamine 101 perchlorate, rhodamine 101 inner salt, meso-(4-hydroxyphenyl)-boron–dipyrromethene (BODIPY), sulforhodamine B sodium salt and fluorescein 27). As a general trend, rhodamine-based dyes are loaded with higher efficiency, when compared with BODIPY and fluorescein dyes. Between the rhodamine-based dyes, their charge and the solvent in which the loading process is carried out play important roles for the amount of cargo that can be loaded into the materials. The delivery experiments carried out in PBS buffer at pH 7.4 reveal for all the materials that anionic dyes are more efficiently released compared to their neutral or cationic counterparts. The overall best performance is achieved with the negatively charged sulforhodamine B dye in acetonitrile. This material also shows a high delivery degree in PBS buffer.

Preparation, characterization, and in vitro release study of vincristine sulfate-loaded chitosan–polyethylene glycol–oleic acid composites

Vincristine sulfate (VCS) was used in combination with other chemotherapeutic agents for the treatment of a variety of cancers, including acute lymphoblastic leukemia, cervical cancer, and breast cancer. However, rapid release of the drug at the site of specific action was still a challenge for antitumor treatment. Recently, hybrid carriers bearing the versatile properties of each component were promising materials in order to improve the effects of therapeutic drugs. This work aimed to prepare and characterize chitosan (CHS)–polyethylene glycol (PEG)–oleic acid (OA) composites as a carrier for VCS delivery. The structure, thermal stability, and surface morphology of CHS/PEG/OA composites were characterized by using Fourier transform infrared spectroscopy, thermal gravimetric analysis, differential thermal analysis, differential scanning calorimeter, scanning electron microscopy, and atomic force microscopy. Additionally, swelling degree, water uptake capacity, gas permeability, water contact angle, and in vitro hydrolytic degradation properties of the composites were examined in detail. The VCS-loaded CHS/PEG/OA composites were prepared and drug-loading efficiency was evaluated. CPO-2 sample with a loading efficiency of 64.1 ± 0.6% was selected for in vitro release. due to the highest drug loading efficiency. In vitro release behavior was performed in phosphate-buffered saline buffer (pH 7.4). The release of VCS was completed in almost 24 h and the release data were best fitted to Korsmeyer–Peppas model. The release results revealed that CHS/PEG/OA composites with slow-release behavior could be a promising drug carrier for therapeutic drugs such as VCS.

Effect of Temperature and Flow Rate on the Cell-Free Area in the Microfluidic Channel.

Blood cell manipulation in microdevices is an interesting task for the separation of particles, by their size, density, or to remove them from the buffer, in which they are suspended, for further analysis, and more. This study highlights the cell-free area (CFA) widening based on experimental results of red blood cell (RBC) flow, suspended in a microfluidic device, while temperature and flow rate incrementally modify RBC response within the microflow. Studies of human red blood cell flow, at a concentration of 20%, suspended in its autologous plasma and phosphate-buffered saline (PBS) buffer, were carried out at a wide flow rate, varying between 10 and 230 μL/min and a temperature range of 23 °C to 50 °C. The plotted measures show an increment in a CFA near the channel wall due to cell flow inertia after a constricted channel, which becomes more significant as temperature and flow rate increase. The temperature increment widened the CFA up to three times. In comparison, flow rate increment increased the CFA up to 20 times in PBS and 11 times in plasma.

Fabrication and Biodegradability of Starch Cell-Plastics as Recyclable Resources

Recently, cell-plastics, which are composed of unicellular green algal cells and biodegradable compounds as ingredients and fillers, have been suggested as carbon-recyclable materials instead of petroleum-based plastics. In this study, cell-plastics, fabricated with Chlamydomonas reinhardtii as an ingredient and a mixture of two types of starches (raw and oxidized starches) as a filler, were successfully stabilized as independent structures despite the quantity of algal cells being nine times more than that of starch. All starch cell-plastics were water repellent, possibly due to their bumpy surface structures. The starch cell-plastic, composed of 50% cells and 50% starch (1.5:1 of oxidized starch versus raw starch), showed 327 ± 52 MPa as Young’s modulus and 6.45 ± 1.20 MPa as tensile strength, indicating the possibility to be a suitable replacement for petroleum-based plastics. Additionally, all starch cell-plastics showed water-repellency and maintained those structures dipped in phosphate-buffered saline buffer as a water environment for 24 h, meaning that all starch cell-plastics had evaluable water resistance. On the other hand, by adding α-amylase, all starch cell-plastics were collapsed and lost the weight efficiently, indicated their biodegradability. This is the first paper to describe starch cell-plastics from their fabrication to biodegradation.

Life-Inspired Endogenous Dynamic Behavior of Lipid Droplet-like Microcompartments in Artificial Adipocyte-like Structures

Chemical systems that can replicate cellular behaviors are gaining increasing attention and are being used to study various biological processes. Here, a protein- or amylose-based assembly at an oi...

Coordination Polymers Integrating Metalloimmunology with Immune Modulation to Elicit Robust Cancer Chemoimmunotherapy

Nanoscale coordination polymers (NCPs) constructed by metal ions and organic ligands via metalligand bonds have attracted great attention for their biomedical application. Herein, a new type of NCP...

Development and validation of Loop-Mediated Isothermal Amplification (LAMP) detection limit using blood matrix spike for Candida glabrata detection

Background: Rapid and accurate identification of yeast responsible for invasive candidiasis (IC) allows for focused and early initiation of therapy for good clinical outcome. Candida glabrata is increasingly important, and the diagnostic sensitivity of microbial culture method “gold standard” is low and could miss up to 50% of the IC patients. To develop and validate LAMP technique detection limit in comparison to microbial culture and PCR techniques using blood matrix spike for C. glabrata detection. Methods and materials: Blood spiking experiment was conducted using healthy blood sample. Candida glabrata ATCC 2001 reference strain colonies were re-suspended in phosphate-buffered saline (PBS) buffer to 0.5 McFarland standard. Ten-fold serial dilutions of yeast suspensions in 1x PBS was made from 106 to 101 cfu/mL concentrations. A 100 μL from each dilution was plated onto SDA and the resulting number of colonies was established. A 25 μL of each dilution was spiked in 225 μL of blood sample (1:10 dilution). The C. glabrata DNA was extracted from spiked blood using Qiagen yeast DNA extraction kit. The developed LAMP assay detects C. glabrata using a primer set (three pairs) (FIP/BIP, F3/B3 and LF/LB) that recognized eight distinct regions on the target internal transcribed spacer (ITS) gene, while, ITS1/4 universal primers were used in PCR analysis. The cfu/mL detection limit of the LAMP was compared to culture and PCR techniques. Results: The LAMP assay analysis of DNA from spiked blood, indicates detection limit of 101 cfu/mL (4.03 x 101 cells/25 μL) using gel electrophoresis analysis. The PCR detection limit was 105 cfu/mL (4.03 x 104 cells/25 μL) and the culture detection limit was 104 cfu/mL (1.61 x 106 cells/mL). Conclusion: The LAMP assay indicates high sensitivity of C. glabrata ITS detection from spiked blood compared to PCR and therefore, a good diagnostic tool for molecular analysis.

Double-Stranded DNA Matrix for Photosensitization Switching

Photosensitization, originated from the activation of triplet states, is the basis of many photodynamic applications, but often competes with a series of nonradiative processes. Herein, we communic...

Oxygenation state of hemoglobin defines dynamics of water molecules in its vicinity.

This study focuses on assessing the possible impact of changes in hemoglobin (Hb) oxygenation on the state of water in its hydration shell as it contributes to red blood cell deformability. Microwave Dielectric Spectroscopy (MDS) was used to monitor the changes in interactions between water molecules and Hb, the number of water molecules in the protein hydration shell, and the dynamics of pre-protein water in response to the transition of Hb from the tense (T) to the relaxed (R) state, and vice versa. Measurements were performed for Hb solutions of different concentrations (5 g/dl-30 g/dl) in phosphate-buffered saline buffer. Cole-Cole parameters of the main water relaxation peak in terms of interactions of water molecules (dipole-dipole/ionic dipole) during the oxygenation-deoxygenation cycle were used to analyze the obtained data. The water mobility-represented by α as a function of ln τ-differed dramatically between the R (oxygenated) state and the T (deoxygenated) state of Hb at physiologically relevant concentrations (30 g/dl-35 g/dl or 4.5 mM-5.5 mM). At these concentrations, oxygenated hemoglobin was characterized by substantially lower mobility of water in the hydration shell, measured as an increase in relaxation time, compared to deoxyhemoglobin. This change indicated an increase in red blood cell cytosolic viscosity when cells were oxygenated and a decrease in viscosity upon deoxygenation. Information provided by MDS on the intraerythrocytic water state of intact red blood cells reflects its interaction with all of the cytosolic components, making these measurements powerful predictors of the changes in the rheological properties of red blood cells, regardless of the cause.