Agarose Gel Matrix Research Articles

Establishment of 3D Cultures of Myometrium, Leiomyoma, and Leiomyosarcoma Cells: Advantages and Disadvantages of Two Different Models.

Uterine leiomyomas are the most common benign, monoclonal, gynaecological tumors in a woman's uterus, while leiomyosarcoma is a rare but aggressive condition caused by the malignant transformation of the myometrium. To overcome the common obstacles related to the methods usually used to study these pathologies, we aimed to devise three-dimensional models of myometrium, uterine leiomyoma and leiomyosarcoma cell lines, using two different types of biocompatible scaffolds. Specifically, we exploited the agarose gel matrix in common 6-well plates and the alginate matrix using Bioprinting INKREDIBLE + (CELLINK), a pneumatic extruded base equipped with a system with double printheads, and a UV printer LED curing system. Both methods allowed the development of 3D spheroids of all three cell types, that were also suitable for morphological investigations. We showed that all cell types embedded in both agarose and alginate formed spheroids in their growth medium. The spheroids successfully proliferated and self-organized into complex structures, developing a sustainable system that emulated the condition of the tissues through the accumulation of extracellular matrix. These models could be useful for a better understanding of pathophysiology, etiopathogenesis, and testing new methods or molecules from a preventive and therapeutic point of view.

Swellable Biopolymer Composite Microneedle Patch for Pain-Free Collection of Interstitial Fluid to Analyze Multiple Biomolecules.

Sampling of interstitial fluid (ISF) using microneedle (MN) patch offers a pain-free minimally invasive alternative to syringe needle-based blood sample collection. However, there is a challenge in the development of MN patch that provides swelling behavior with sufficient mechanical strength for skin penetration. Here, we report fabrication of MN patch made of biopolymer composite containing iota-carrageenan, gelatin, and polyethylene glycol. Calcium chloride was used as a crosslinker to improve mechanical strength. MN patch was characterized for integrity, swelling behavior, mechanical strength, aspiration of fluid from agarose gel, and the excised porcine ear skin. An array of 361 MNs was able to aspirate 36 ± 5 and 14 ± 1 μL fluid after application in agarose gel matrix and the ex vivo porcine skin model, respectively. MN patch applied in vivo rat model for 30 min resulted in the collection of ISF containing 267 ± 128 mg/dL, 24 ± 13 mg/dL, and 0.6 ± 0.4 mIU/mL of glucose, uric acid and thyroid stimulating hormone (TSH), respectively. The concentration of glucose, uric acid, and TSH in rat blood was found to be 199 ± 47 mg/dL, 8.4 ± 6 mg/dL, and 1.1 ± 0.6 mIU/mL at the same time. Furthermore, MN patch applied on the forearm of 10 healthy human volunteers for 30 min was able to aspirate 32 ± 14 μL of ISF. The concentration of glucose, uric acid, and TSH determined from ISF samples of human volunteers was 64 ± 25 mg/dL, 4.2 ± 4.1 mg/dL, and 0.16 ± 0.08 mIU/mL, respectively. The visual analogue scale (VAS) pain score after MN application was lower compared with hypodermic syringe needle insertion. Taken together, biopolymer composite-based swellable MN patch can be developed for collection of ISF for simultaneous determination of multiple biomolecules in a minimally invasive manner.

B-079 Characterization of an isoelectric focusing method for detection of IgG oligoclonal banding in paired cerebrospinal fluid and serum specimens

Abstract Background Qualitative assessment of IgG-specific oligoclonal banding (OCB) in paired serum and cerebrospinal fluid (CSF) samples is useful for evaluating inflammatory conditions of the central nervous system such as multiple sclerosis. Here we characterized the performance of an IgG-specific method using isoelectric focusing on agarose gel matrix for the detection of OCB in paired serum and CSF samples. Methods Specimens of 20 paired, simultaneously collected CSF and serum patient samples were tested on Sebia (Hydrasys 2 System) provided by the National Institutes of Health (NIH) Diagnostic Laboratories. We tested these paired samples using the Helena IgG IFE-20 kit (SPIFE® Touch) method and the results were read by two independent individuals blinded to each other’s assessments. The results were compared to the NIH results for agreement. Positive Percent Agreement (PPA) and Negative Percent Agreement (NPA) were calculated. Analytical sensitivity of the Helena assay was assessed via serial dilutions of a CSF OCB positive sample (total IgG 4.5 mg/dL). Results Figure 1 shows serum and CSF pairs for the control (A), two example positive OCB patients (B & D) and a negative OCB patient (C). The Helena assay was concordant with Sebia for 11/12 positive OCB patients (PPA 91.6%) and 8/8 negative subjects (NPA 100%). 20-fold was the highest dilution that remained positive. Conclusions OCB detection using paired serum and CSF samples and isoelectric focusing electrophoresis is considered the preferred method. The Helena IgG IFE-20 assay is such a method and showed high PPA and NPA concordance with the Sebia System. Thus, the Helena OCB assay can be considered an accurate and analytically sensitive method for assessing OCB in serum and CSF.

Chemically fueled dynamic switching between assembly-encoded emissions.

Self-assembly provides access to non-covalently synthesized supramolecular materials with distinct properties from a single building block. However, dynamic switching between functional states still remains challenging, but holds enormous potential in material chemistry to design smart materials. Herein, we demonstrate a chemical fuel-mediated strategy to dynamically switch between two distinctly emissive aggregates, originating from the self-assembly of a naphthalimide-appended peptide building block. A molecularly dissolved building block shows very weak blue emission, whereas, in the assembled state (Agg-1), it shows cyan emission through π stacking-mediated excimer emission. The addition of a chemical fuel, ethyl-3-(3-(dimethylamino)propyl)carbodiimide (EDC), converts the terminal aspartic acid present in the building block to an intra-molecularly cyclized anhydride in situ forming a second aggregated state, Agg-2, by changing the molecular packing, thereby transforming the emission to strong blue. Interestingly, the anhydride gets hydrolyzed gradually to reform Agg-1 and the initial cyan emission is restored. The kinetic stability of the strong blue emissive aggregate, Agg-2, can be regulated by the added concentration of the chemical fuel. Moreover, we expand the scope of this system within an agarose gel matrix, which allows us to gain spatiotemporal control over the properties, thereby producing a self-erasable writing system where the chemical fuel acts as the ink.

Developing a medical device-grade T2 phantom optimized for myocardial T2 mapping by cardiovascular magnetic resonance

IntroductionA long T2 relaxation time can reflect oedema, and myocardial inflammation when combined with increased plasma troponin levels. Cardiovascular magnetic resonance (CMR) T2 mapping therefore has potential to provide a key diagnostic and prognostic biomarkers. However, T2 varies by scanner, software, and sequence, highlighting the need for standardization and for a quality assurance system for T2 mapping in CMR. AimTo fabricate and assess a phantom dedicated to the quality assurance of T2 mapping in CMR. MethodA T2 mapping phantom was manufactured to contain 9 T1 and T2 (T1|T2) tubes to mimic clinically relevant native and post-contrast T2 in myocardium across the health to inflammation spectrum (i.e., 43–74 ms) and across both field strengths (1.5 and 3 T). We evaluated the phantom's structural integrity, B0 and B1 uniformity using field maps, and temperature dependence. Baseline reference T1|T2 were measured using inversion recovery gradient echo and single-echo spin echo (SE) sequences respectively, both with long repetition times (10 s). Long-term reproducibility of T1|T2 was determined by repeated T1|T2 mapping of the phantom at baseline and at 12 months. ResultsThe phantom embodies 9 internal agarose-containing T1|T2 tubes doped with nickel di-chloride (NiCl2) as the paramagnetic relaxation modifier to cover the clinically relevant spectrum of myocardial T2. The tubes are surrounded by an agarose-gel matrix which is doped with NiCl2 and packed with high-density polyethylene (HDPE) beads. All tubes at both field strengths, showed measurement errors up to ≤ 7.2 ms [< 14.7%] for estimated T2 by balanced steady-state free precession T2 mapping compared to reference SE T2 with the exception of the post-contrast tube of ultra-low T1 where the deviance was up to 16 ms [40.0%]. At 12 months, the phantom remained free of air bubbles, susceptibility, and off-resonance artifacts. The inclusion of HDPE beads effectively flattened the B0 and B1 magnetic fields in the imaged slice. Independent temperature dependency experiments over the 13–38 °C range confirmed the greater stability of shorter vs longer T1|T2 tubes. Excellent long-term (12-month) reproducibility of measured T1|T2 was demonstrated across both field strengths (all coefficients of variation < 1.38%). ConclusionThe T2 mapping phantom demonstrates excellent structural integrity, B0 and B1 uniformity, and reproducibility of its internal tube T1|T2 out to 1 year. This device may now be mass-produced to support the quality assurance of T2 mapping in CMR.

Influence of a Polyneurotransmitter on DNA-Mediated Förster-Based Resonance Energy Transfer: A Path Leading to White Light Generation.

The physiologically important biomolecule, dopamine (DA), shows strong self-oxidation and aggregation behaviors, which have been controlled and modulated to result in fluorescent polydopamine (F-PDA) nanoparticles. On the other hand, the simultaneous binding of two diverse deoxyribonucleic acid (DNA) binding probes, 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) and ethidium bromide (EtBr), has been elaborately established to follow the Förster-based resonance energy transfer (FRET) pathway. The comparative understanding of this DNA-mediated FRET in three media, phosphate buffer saline (PBS) of pH 7.4, DA, and F-PDA, has concluded that the FRET efficiency in the three media follows the order: PBS > DA > F-PDA. This controlled FRET in the fluorescent F-PDA matrix serves a pivotal role for efficient white light (WL) generation with excellent Commission Internationale de l'Eclairage (CIE) parameters that match well with that of pure WL emission. The obtained WL emission has been shown to be very specific with respect to concentrations of different participating components and the excitation wavelength of the illuminating source. Furthermore, the optical properties of the WL emitting solution have been observed to be retained excellently inside the well-known agarose gel matrix. Finally, the mechanistic pathway behind such a FRET-based WL generation has been established in detail, and to the best of our knowledge, the current study offers the first and only report that discloses the influence of a fluorescent polyneurotransmitter matrix for successful generation of WL emission.

Single step immobilization of CMCase within agarose gel matrix: Kinetics and thermodynamic studies

In the current study, CMCase from Bacillus licheniformis KIBGE-IB2 was immobilized within the matrix of agarose gel through entrapment technique. Maximum immobilization yield (%) of the enzyme was obtained when 2.0 % agarose was used. The activation energy (Ea) of the enzyme increased from 16.38 to 44.08 kJ mol−1 after immobilization. Thermodynamic parameters such as activation energy of deactivation (ΔGd), enthalpy (ΔHd) and entropy (ΔSd) of deactivation, deactivation rate constant (Kd), half-life (t1/2), D-value and z-value were calculated for native/free and immobilized CMCase. The maximum reaction rate (Vmax) of the native enzyme was found to be 8319.47 U ml−1 min−1, which reduced to 7218.1 U ml−1 min−1after immobilization process. However, the Michaelis-Menten constant (Km) value of the enzyme increased from 1.236 to 2.769 mg ml−1 min−1 after immobilization. Immobilized enzyme within agarose gel matrix support can be reuse up to eight reaction cycles. Broad stability profile and improved catalytic properties of the immobilized CMCase indicated that this enzyme can be a plausible candidate to be used in various industrial processes.

Honeywell introduces next- generation catalyst to address ‘smell in cabin’ events

In the current study, CMCase from Bacillus licheniformis KIBGE-IB2 was immobilized within the matrix of agarose gel through entrapment technique. Maximum immobilization yield (%) of the enzyme was obtained when 2.0 % agarose was used. The activation energy (Ea) of the enzyme increased from 16.38 to 44.08 kJ mol−1 after immobilization. Thermodynamic parameters such as activation energy of deactivation (ΔGd), enthalpy (ΔHd) and entropy (ΔSd) of deactivation, deactivation rate constant (Kd), half-life (t1/2), D-value and z-value were calculated for native/free and immobilized CMCase. The maximum reaction rate (Vmax) of the native enzyme was found to be 8319.47 U ml−1 min−1, which reduced to 7218.1 U ml−1 min−1after immobilization process. However, the Michaelis-Menten constant (Km) value of the enzyme increased from 1.236 to 2.769 mg ml−1 min−1 after immobilization. Immobilized enzyme within agarose gel matrix support can be reuse up to eight reaction cycles. Broad stability profile and improved catalytic properties of the immobilized CMCase indicated that this enzyme can be a plausible candidate to be used in various industrial processes.

An organogel library for solution NMR analysis of nanoparticle suspensions in non-aqueous samples

Surface contrast solution NMR methods (scNMR) are emerging as powerful tools to investigate the adsorption of small molecule ligands to the surface of nanoparticles (NP), returning fundamental insight into the kinetics and thermodynamics of sorption, as well as structural information on the adsorbed species. A prerequisite for the acquisition of high quality solution NMR data is the preparation of homogeneous and stable samples that return consistent NMR spectra and allow extensive signal averaging. Unfortunately, this condition does not apply to NMR samples containing NPs that often show a tendency to sediment and accumulate at the bottom of the NMR tube over the course of the experiment. We have recently shown that preparing NMR samples in an agarose gel matrix inhibits sedimentation and allows the characterization of small molecule-NP interactions by scNMR. Unfortunately, as the agarose gel only forms in aqueous solution, this sample preparation method cannot be used to stabilize NP suspensions in a non-aqueous environment. Here, we introduce a library of 48 organogels, based on low molecular-mass organic gelators (LMOGs), to prepare NMR samples of small molecule/NP systems in a wide range of organic solvents. In addition, we present a simple method that takes advantage of 1H transverse relaxation (1H-R2) measurements to screen the library and identify the best gelator to characterize the small molecule-NP interaction of interest in the solvent of choice. We expect the results of this study will enable the preparation of homogeneous and stable samples of NPs in non-aqueous environments, therefore dramatically increasing the applicability of scNMR to the characterization of heterogeneous interactions and to the investigation of the role played by solvent molecules in regulating the kinetics and thermodynamics of sorption.

Development and Evaluation of a Versatile Receptor-Ligand Binding Assay Using Cell Membrane Preparations Embedded in an Agarose Gel Matrix and Evaluation with the Human Adenosine A1Receptor

Guanosine-5'-triphosphate (GTP)-binding protein-coupled receptors are the target of up to 40% of prescribed medications worldwide. To evaluate the suitability of novel receptor ligands, frequently elaborate, time-consuming, and expensive receptor-ligand interaction studies have to be carried out. This work describes the development and proof of principle of a rapid, sensitive, and reliable receptor-ligand binding assay. CHO cells were stably transfected with a construct encoding the human A1 adenosine receptor (hA1AR). For ligand binding assays, membranes from these cells were prepared and embedded in low melting point agarose. These "immobilized" samples were incubated with tritiated 8-cyclopentyl-1,3-dipropylxanthine ([3H]DPCPX), a well-established receptor antagonist. The KD and Bmax values as well as kinetic parameters (kon and koff) of receptor-ligand interaction were determined. Unspecific binding of various radiotracers to either the carrier material or the agarose gel matrix was negligible. The dissociation constant (KD) for [3H]DPCPX at the hA1AR was determined by saturation, competition binding, and kinetic experiments. These studies resulted in KD values of ∼3 nM, which is in good accordance with previously published data obtained from conventional receptor-ligand binding assays. The procedure described in this study simplifies classical binding studies to a kit-like assay. The receptors retained their binding properties even when preparations were dried completely. Transport and delivery of the material are conceivable without loss of biological activity. Therefore, other laboratories can perform binding studies without special equipment or the necessity to run a cell culture laboratory and/or to dissect tissue on their own.

Plasmonic gel nanocomposites for detection of high energy electrons.

Radiation therapy is a common treatment modality employed in the treatment of cancer. High energy photons are the primary source of radiation but when administered, they leave an exit dose resulting in radiation damage to the adjacent healthy tissues. To overcome this, high energy electrons are employed in cases of skin cancer to minimize radiation induced toxicity. Despite these advances, measurement of delivered radiation remains a challenge due to limitations with existing dosimeters including labor intensive fabrication, complex read-out techniques and post-irradiation instability. To overcome these limitations, we have developed a novel colorimetric plasmonic gel nanocomposite for the detection of therapeutic levels of radiation delivered in electron beam therapy. The plasmonic nanocomposite consists of an agarose gel matrix encapsulating precursor gold ions, which are reduced to gold nanoparticles as a result of exposure to high energy electrons. The formation of gold nanoparticles renders a change in color to the agarose matrix, resulting in the formation of plasmonic gel nanocomposites. The intensity of the color formed exhibits a linear relation with the delivered electron dose, which can be quantified using absorbance spectroscopy. The plasmonic gel nanocomposites were able to detect doses employed in fractionated electron therapy, including in an anthropomorphic phantom used for planning radiation treatments in the clinic. Furthermore, the use of glutathione as a quenching agent facilitated qualitative and quantitative spatial mapping of the delivered dose. Our results indicate that the ease of fabrication, simplicity of detection and quantification using absorbance spectroscopy, determination of spatial dose profiles, and relatively low cost make the plasmonic gel nanocomposite technology attractive for detecting electron doses in the clinic.

MR Imaging Enables Real-Time Monitoring ofInVitro Electrolytic Ablation of Hepatocellular Carcinoma.

To evaluate the capability of T2-weighted magnetic resonance (MR) imaging to monitor electrolytic ablation-induced cell death in real time. Agarose phantoms arranged as an electrolytic cell were exposed to varying quantities of electric charge under constant current to create a pH series. The pH phantoms were subjected to T2-weighted imaging with region of interest quantitation of the acquired signal intensity. Subsequently, hepatocellular carcinoma (HCC) cells encapsulated in an agarose gel matrix were subjected to 10 V of electrolytic ablation for variable lengths of time with and without concurrent T2-weighted MR imaging. Cellular death was confirmed by a fluorescent reporter. Finally, to confirm that real-time MR images corresponded to ablation zones, 10 V electrolytic ablations were performed followed by the addition of pH-neutralizing 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer. Analysis of MR imaging from agarose gel pH phantoms demonstrated a relationship between signal intensity and pH at the anodes and cathodes. The steep negative phase of the anode model (pH < 3.55) and global minimum of the cathode model (pH ≈ 11.62) closely approximated established cytotoxic pH levels. T2-weighted MR imaging demonstrated a strong correlation of ablation zones with regions of HCC cell death (r= 0.986; R2= 0.916; P < .0001). The addition of HEPES buffer to the hydrogel resulted in complete obliteration of MR imaging-observed ablation zones, confirming that change in pH directly caused the observed signal intensity attenuation of the ablation zone. T2-weighted MR imaging enabled the real-time detection of electrolytic ablation zones, demonstrating a strong correlation with histologic cell death.

Quantifying Replication Fork Progression at CTG Repeats by 2D Gel Electrophoresis.

Physical separation of branched DNA from linear molecules is based on the difference of mobility of linear versus branched DNA during two-dimensional agarose gel electrophoresis. Structured DNA migrates as slower species when compared to linear DNA of similar molecular weight. Metabolic processes such as S phase replication or double strand-break repair may generate branched DNA molecules. Trinucleotide repeats are naturally prone to form secondary structures that can modify their migration through an agarose gel matrix. These structures may also interfere in vivo with replication, by slowing down replication-fork progression, transiently stalling forks, possibly leading to secondary structure such as Holliday junctions or hemicatenanes. Alternatively, reversed replication forks may occur following fork stalling, disrupting replication dynamics and modifying DNA migration on agarose gel. So although two-dimensional agarose gel electrophoresis theoretically allows to resolve a mixture of structured DNA molecules and quantify them by radioactive hybridization, its practical application to trinucleotide repeats faces some serious technical challenges.

High Sensitivity Measurement of Transcription Factor-DNA Binding Affinities by Competitive Titration Using Fluorescence Microscopy.

Accurate quantification of transcription factor (TF)-DNA interactions is essential for understanding the regulation of gene expression. Since existing approaches suffer from significant limitations, we have developed a new method for determining TF-DNA binding affinities with high sensitivity on a large scale. The assay relies on the established fluorescence anisotropy (FA) principle but introduces important technical improvements. First, we measure a full FA competitive titration curve in a single well by incorporating TF and a fluorescently labeled reference DNA in a porous agarose gel matrix. Unlabeled DNA oligomer is loaded on the top as a competitor and, through diffusion, forms a spatio-temporal gradient. The resulting FA gradient is then read out using a customized epifluorescence microscope setup. This improved setup greatly increases the sensitivity of FA signal detection, allowing both weak and strong binding to be reliably quantified, even for molecules of similar molecular weights. In this fashion, we can measure one titration curve per well of a multi-well plate, and through a fitting procedure, we can extract both the absolute dissociation constant (KD) and active protein concentration. By testing all single-point mutation variants of a given consensus binding sequence, we can survey the entire binding specificity landscape of a TF, typically on a single plate. The resulting position weight matrices (PWMs) outperform those derived from other methods in predicting in vivo TF occupancy. Here, we present a detailed guide for implementing HiP-FA on a conventional automated fluorescent microscope and the data analysis pipeline.

English

Soil salinity is a major abiotic stress that affects rice production. It can reduce yield drastically and result in total crop failure. The objectives of this study are to determine the genetic diversity within thirty-six rice accessions and to identify genotypes that are tolerant to salinity. Thirty-six rice accessions including three check varieties were sown in experimental pots and their leaves harvested for DNA extraction. Screening was done with 31 simple sequence repeats (SSRs) primers, of which 14 were markers for salt tolerance, 2 primers did not produce any results. 28 out of the 31 primers were polymorphic. The polymerase chain reaction (PCR) products were run and visualized on a 3% agarose gel matrix stained with ethidium bromide. Amplified bands were scored and analyzed with PowerMarker v3.25 and DARwin v5 software. The genetic diversity among the accessions assembled was high (He=0.6, I=0.516, PIC=0.471). Saltol primers RM10711 and RM10793 were the only primers able to completely discriminate tolerant genotypes from susceptible ones, hence they can be used in selections involving the genotypes. Accessions SR1, IR72, Sebota 337-1, Perfume (Short) type, Anyofula, Local Red, GR18Red, GH1580, GH1528, GH1575, NericaL23, NericaL24 and NericaL27 performed well under salinity stress in this study and were identified to be superior among the accessions used. These accessions should be incorporated into major breeding programs to improve the salt tolerance of existing commercial lines or for the production of new commercial lines. Key words: Rice, abiotic stress, agarose gel, genetic diversity, polymerase chain reaction (PCR), simple sequence repeats (SSRs) markers, salinity. &nbsp

Carbon quantum dots functionalized agarose gel matrix for in solution detection of nonylphenol

ABSTRACTNonylphenol, an endocrine disrupter, is widely released to the aquatic environment, which is accumulative and extremely toxic to aquatic organisms. Here, we report a simple and cost-effective large-scale green synthesis of water-soluble highly fluorescent carbon quantum dots (CQDs) from marine biowaste (offshore washed algae) which gets quenched strongly in the presence of nonylphenol. These CQDs were around 20–40 nm in size and exhibit fluorescence constantly at 360 nm. The XRD profile depicted the interlayer spacing in the particle as 0.284 nm with a humped peak around 14 degrees showing the amorphous nature of the CQDs. FTIR spectra showed the stretching vibration of the hydroxyl groups (OH), asymmetric and symmetric stretching vibrations of the carboxylate anions (COO–). The fluorescence quantum yield of the CQDs is up to 68% and nonyl phenol detection limit is less than 0.1 µM. Furthermore, the CQDs were found to be stable at a wide pH range which makes it a suitable nonylphenol sensor for a variety of environmental samples. We functionalized these CQDs on an agarose gel matrix to develop a convenient sensor for the rapid detection of nonylphenol.

Assessing the synergy effect of additive and matrix on single-crystal growth: Morphological revolution resulted from gel-mediated enhancement on CIT-calcite interaction

It is well known that in biomineralization, the inorganic solids crystallized in the presence of organic phases, which are generally recognized as additives and matrix, leading to the crystal morphology modification. However, the synergy effects of both soluble additive and insoluble matrix on regulating the morphology of synthetic single-crystals are less studied. Here, we examine the morphological revolution of calcite single crystals induced by the additive, citrate (CIT), or/and the matrix, agarose gel network. The agarose gel matrix is inert to the crystal morphology in the sense that the agarose gel-grown calcite crystals maintain in characteristic rhombohedra. In contrast, CIT additives are active in crystal morphology modification and crystals begin to exhibit curved rough surfaces when grown in solution with the concentration of CIT coated Au nanoparticles ([CIT-Au NPs]) of more than 2.25mg/mL. Interestingly, once agarose gel and CIT-Au NPs are simultaneously introduced, the curved morphological feature emerges at a much lower [CIT-Au NPs] of around 0.2mg/mL. Increasing the gel concentrations further reduce the [CIT-Au NPs] needed to trigger calcite morphological modification, suggesting that the gel networks reduce the CIT diffusion and thereby enhance the kinetic effects of CIT on crystallization. As such, this work may have implications for understanding the mechanism of hierarchical biominerals construction and provide rational strategy to control single-crystal morphologies.

Dynamics of a camphoric acid boat at the air–water interface

We report experiments on an agarose gel tablet loaded with camphoric acid (c-boat) spontaneously set into motion by surface tension gradients on the water surface. We observe three distinct modes of c-boat motion: harmonic mode where the c-boat speed oscillates sinusoidally in time, a steady mode where the c-boat maintains constant speed, and an intermittent mode where the c-boat maintains near-zero speed between sudden jumps in speed. Whereas all three modes have been separately reported before in different systems, controlled release of Camphoric Acid (CA) from the agarose gel matrix allowed the observation of all the three modes in the same system. These three modes are a result of a competition between the driving (surface tension gradients) and drag forces acting on the c-boat. Moreover we suggest that there exist two time scales corresponding to spreading of CA and boat motion and the mismatch of these two time scales give rise to the three modes in boat motion. We reproduced all the modes of motion by varying the air–water interfacial tension using Sodium Dodecyl Sulfate (SDS).

In vitro and in vivo anticancer activity of posterior salivary gland toxin from the cuttlefish Sepia pharaonis, Ehrenberg (1831)

Posterior salivary gland (PSG) toxins are high molecular weight toxins secreted by cephalopods and gastropods which possess immense potentials in biomedical applications. In the present study, the biomedical potentials of the PSG toxin from the cuttlefish, S. pharaonis was determined in vitro and in vivo. The cytostatic potentials of the PSG toxin was determined by the lymphocyte migration inhibition assay. The PSG toxin (50 μg/ml) effectively inhibited the migration of lymphocytes across the agarose gel matrix under the presence of lipopolysaccharide mitogen. The cytotoxicity of the PSG toxin against cancer cell lines was determined using the MTT assay. The PSG toxin exhibited highest cytotoxicity against the MCF-7 breast cancer cells (IC50-10.64 μM) followed by KB, HeLa and A549 cells. The PSG toxin also exhibited proportional release of LDH leakage by mitochondrial damage with an IC50-13.85 μM against MCF-7 breast cancer cells. Flow cytometry analysis revealed that the PSG toxin induced apoptosis in MCF-7 cells by cell cycle arrest at G0/G1 phase. The PSG toxin (80 mg/kg b.w.) exhibited pronounced reduction (29%) in tumor growth in experimentally induced breast carcinoma in female Balb/C mice, in vivo. Hematological analysis illustrated the restoration of blood and biochemical parameters by the PSG toxin in mice induced with tumor. Histopathology studies also revealed the restitution of morphological features in the mammary tumor and vital organs in mice treated with the PSG toxin without any observed toxicity and adverse effects. The PSG toxin further exhibited commendable potentials in the prevention of tumor metastasis into immediate organs viz lungs, thus functioning as an anti-metastatic agent. The results of the present study showed that the PSG toxin exhibited immense promise as a potential peptide based anticancer agent, in future.

Characteristics of modified radiochomic gel Turnbull-Blue

This work presents a dosimetric characterization of the modified radiochromic gel Turnbull-Blue (TB). Formaldehyde a cross-link agent was added to the composition. This modification raised the melting point of agarose gel to 55°C, 22°C above the agarose gel matrix. For this new gel formulation the energy, dose-rate dependence and Diffusion coefficient were verified. The modified TB gel showed higher sensitivity in the 6 MV than 15 MV beam. Dose rate dependence was evaluated from 100 to 500 cGy/min using a 15MV linear accelerator. The results show variations in sensitivity for dose rate dependence. The addition of formaldehyde does not affects the diffusion coefficient for the modified Turnbull-Blue.