Lactoferrin Isolation Using Monolithic Column Coupled with Spectrometric or Micro-Amperometric Detector

Changes in the Lactoferrin Concentration in the Bovine Colostrum During Postpartum Period

The health condition of the mammary gland is highly crucial for obtaining good quality colostrum. The lactoferrin (LF), as an iron-binding protein, plays a key role in the defense mechanisms of the mammary gland due to its’ bacteriostatic properties. The study aimed to investigate the factors affecting the LF concentration in the bovine colostrum milk during the postpartum period, and the effect of somatic cell count (SCC) on the LF concentration and milk composition. The cows were randomly selected at a dairy farm in Pelagonia region. Colostrum samples from 12 cows were collected. Samples were taken at different time intervals after parturition, 1, 6, 12, 24, 48, 72, 96, and 120 h after parturition. Cows in their second parity were found to have higher levels of LF compared to cows in the third and higher parity (p>0.05). Time had a significant effect on the LF concentration (p<0.01), with the highest value recorded 1 h after parturition remaining stable for one hour. LF concentration and SCC in the colostrum showed a weak positive correlation (r=0.40; p<0.01). The highest LF concentration was noticed when SCC was above 800,000 cells/mL. In conclusion, the colostrum LF concentration was significantly affected by the interactions of the two factors, i.e., time after parturition and SCC (p<0.05). Milk composition was affected by elevated SCC. Parity showed no association with LF. The SCC can be used as a reliable means of assessing colostrum quality.

ZIF-8 nano confined protein-titanocene complex core-shell MOFs for efficient therapy of Neuroblastoma: Optimization, molecular dynamics and toxicity studies

In the present study, we have developed the core-shell metal organic framework (MOF) of zinc, wherein titanocene dichloride (TC) loaded lactoferrin (Lf) functioned as a core. The complexation of TC to Lf was studies using molecular dynamics study, Quantum mechanical model and spectroscopic investigations. Plackett-Burman design was used to screen and select the critical factors affecting the responses (size, zeta potential and PDI) while the effect of those parameter on the quality attributes (size and yield) was studied by means of a Box-Behnken design. The optimised Lf-TC nanoparticles were loaded inside the ZIF-8 framework along with an anticancer agent 5 Fluorouracil and characterized using techniques like FTIR, PXRD, Raman spectroscopy, EDX and UV-NIR spectroscopy and morphological techniques like SEM, TEM, AFM. The compatibility of the loaded ZIF-8 framework was examined by haemocompatibility studies. The potential of developed nanoplatform against Neuroblastoma was assessed using a cell line studies along with in vivo toxicity studies to ascertain its safety for after in-vivo administration in Wistar rats. Therefore, we can conclude that by employing the approach of DOE we were able to optimize the size and yield of Lf-TC NPs and further by loading inside ZIF-8 framework along with an anticancer drug like 5 fluorouracil we were able to develop a potential nanoplatform for the multimodal therapy of Neuroblastoma.

Characterisation of Lactoferrin Isolated from Acid Whey Using Pilot-Scale Monolithic Ion-Exchange Chromatography

The aim of this study was to characterize the properties of lactoferrin (LF) obtained in a process developed for its isolation from acid whey derived from the production of fresh curd cheese, using a unique technology of ion-exchange chromatography on CIM® monolithic columns. The freeze-dried lactoferrin samples produced on the pilot plant (capacity 1 m3) were examined for the purity, iron-binding capacity, antibacterial activity, and pH- and temperature-stability. Apo-LF inhibited several tested strains (enterobacteria, Staphylococcus, Streptococcus salivarius) except clostridia, lactic acid bacteria, and bifidobacteria. Sample of LF intentionally saturated with Fe3+ lost its antibacterial activity, indicating the involvement of mechanisms based on depriving bacteria of an iron source. All samples, regardless of the iron-saturation level, exhibited stability in pH range 4.0 to 11.0. LF with higher iron content (A-value = 41.9%) showed better thermal stability. Heat treatment up to 72 °C/3 s did not reduce antimicrobial activity against E. coli O157: H7 tox-. Higher purity (above 91%), higher iron-binding capacity and higher inhibitory activity against E. coli O157: H7 tox- compared to some similar products from the market was observed. These results demonstrate a high potential of monolithic ion-exchange chromatography for industrial processing of acid whey as a source of LF that can be used in new products with high-added value. The upscaling of the process is ongoing on a demonstration plant (10–30 m3/day capacity).

Electrochemical microsensors for the detection of cadmium(II) and lead(II) ions in plants

Routine determination of trace metals in complex media is still a difficult task for many analytical instruments. The aim of this work was to compare three electro-chemical instruments [a standard potentiostat (Autolab), a commercially available miniaturized potentiostat (PalmSens) and a homemade micropotentiostat] for easy-to-use and sensitive determination of cadmium(II) and lead(II) ions. The lowest detection limits (hundreds of pM) for both metals was achieved by using of the standard potentiostat, followed by the miniaturized potentiostat (tens of nM) and the homemade instrument (hundreds of nM). Nevertheless, all potentiostats were sensitive enough to evaluate contamination of the environment, because the environmental limits for both metals are higher than detection limits of the instruments. Further, we tested all used potentiostats and working electrodes on analysis of environmental samples (rainwater, flour and plant extract) with artificially added cadmium(II) and lead(II). Based on the similar results obtained for all potentiostats we choose a homemade instrument with a carbon tip working electrode for our subsequent environmental experiments, in which we analyzed maize and sunflower seedlings and rainwater obtained from various sites in the Czech Republic.

Determination of lactoferrin and immunoglobulin g in animal milks by new immunosensors

Two different immunosensors, recently developed for the determination of antibacterial proteins (lactoferrin and immunoglobulin G) in buffalo milk and in other commercial animal milks samples, were used in the present study. The aim was to propose these immunosensor methods for routine control of important diet products, such as cow and goat milks, and in particular buffalo milk. To this end we employed two different kinds of immunosensors: one for the analysis of immunoglobulin G (IgG), the other was a new amperometric immunosensor for lactoferrin analysis. Lactoferrin and IgG immunosensors were also used for the determination of lactoferrin and immunoglobulin G in buffalo milk on different days of lactation.

Determination of Vitamin C (Ascorbic Acid) Using High Performance Liquid Chromatography Coupled with Electrochemical Detection

Vitamin C (ascorbic acid, ascorbate, AA) is a water soluble organic compound that participates in many biological processes. The main aim of this paper was to utilize two electrochemical detectors (amperometric - Coulouchem III and coulometric - CoulArray) coupled with flow injection analysis for the detection of ascorbic acid. Primarily, we optimized the experimental conditions. The optimized conditions were as follows: detector potential 100 mV, temperature 25 °C, mobile phase 0.09% TFA:ACN, 3:97 (v/v) and flow rate 0.13 mL·min-1. The tangents of the calibration curves were 0.3788 for the coulometric method and 0.0136 for the amperometric one. The tangent of the calibration curve measured by the coulometric detector was almost 30 times higher than the tangent measured by the amperometric detector. Consequently, we coupled a CoulArray electrochemical detector with high performance liquid chromatography and estimated the detection limit for AA as 90 nM (450 fmol per 5 μL injection). The method was used for the determination of vitamin C in a pharmaceutical preparations (98 ± 2 mg per tablet), in oranges (Citrus aurantium) (varied from 30 to 56 mg/100 g fresh weight), in apples (Malus sp.) (varied from 11 to 19 mg/100 g fresh weight), and in human blood serum (varied from 38 to 78 μM). The recoveries were also determined.

Utilization of Electrochemical Sensors and Biosensors in Biochemistry and Molecular Biology

A special issue of Sensors entitled “Utilization of Electrochemical Sensors and Biosensors in Biochemistry and Molecular Biology” has been prepared over a period of three years. In this Editorial Note we would like to highlight one of the possible directions for electrochemical sensor and biosensor research resulting from the ideas of Czechoslovakian Nobel Prize winner Jaroslav Heyrovsky and his colleague Rudolf Brdicka.

Amperometric Sensor for Detection of Chloride Ions

Chloride ion sensing is important in many fields such as clinical diagnosis, environmental monitoring and industrial applications. We have measured chloride ions at a carbon paste electrode (CPE) and at a CPE modified with solid AgNO₃, a solution of AgNO₃ and/or solid silver particles. Detection limits (3 S/N) for chloride ions were 100 μM, 100 μM and 10 μM for solid AgNO₃, solution of AgNO₃ and/or solid silver particles, respectively. The CPE modified with silver particles is the most sensitive to the presence chloride ions. After that we approached to the miniaturization of the whole electrochemical instrument. Measurements were carried out on miniaturized instrument consisting of a potentiostat with dimensions 35 × 166 × 125 mm, screen printed electrodes, a peristaltic pump and a PC with control software. Under the most suitable experimental conditions (Britton-Robinson buffer, pH 1.8 and working electrode potential 550 mV) we estimated the limit of detection (3 S/N) as 500 nM.

An Electrochemical Detection of Metallothioneins at the Zeptomole Level in Nanolitre Volumes

An Electrochemical Detection of Metallothioneins at the Zeptomole Level in Nanolitre VolumesWe report on improvement of the adsorptive transfer stripping technique (AdTS) coupled with the differential pulse voltammetry Brdicka reaction to determine a thiol-protein. The current technique has been unable to generate reproducible results when analyzing very low sample volumes (nanolitres). This obstacle can be overcome technically by modifying the current transfer technique including cooling step of the adsorbed analyte. We tested the technique on determination of a promising tumour disease marker protein called metallothionein (MT). The detection limit (3 S/N) of MT was evaluated as 500 zeptomoles per 500 nL (1 pM) and the quantification limit (10 S/N) as 1,500 zeptomoles per 500 nL (3 pM). Further, the improved AdTS technique was utilized to analyze blood serum samples from patients with breast cancer. Based on the results obtained it can be concluded that the improved technique can be used to detect a thiolprotein in very low sample volumes and can also prevent interferences during the washing and transferring step.