Cellulase immobilization on superparamagnetic nanoparticles for reuse in cellulosic biomass conversion

Current cellulosic biomass hydrolysis is based on the one-time use of cellulases. Cellulases immobilized on magnetic nanocarriers offer the advantages of magnetic separation and repeated use for continuous hydrolysis. Most immobilization methods focus on only one type of cellulase. Here, we report co-immobilization of two types of cellulases, β-glucosidase A (BglA) and cellobiohydrolase D (CelD), on sub-20 nm superparamagnetic nanoparticles. The nanoparticles demonstrated 100% immobilization efficiency for both BglA and CelD. The total enzyme activities of immobilized BglA and CelD were up to 67.1% and 41.5% of that of the free cellulases, respectively. The immobilized BglA and CelD each retained about 85% and 43% of the initial immobilized enzyme activities after being recycled 3 and 10 times, respectively. The effects of pH and temperature on the immobilized cellulases were also investigated. Co-immobilization of BglA and CelD on MNPs is a promising strategy to promote synergistic action of cellulases while lowering enzyme consumption

Change in blood glucose level in rats after immobilization

Experiments were carried out on male white rats divided into four groups. In group one the blood glucose level was determined immediately after immobilization. In the other three groups, two hours following immobilization, the blood glucose level was determined every 20 minutes for 3 hours 40 minutes by the glucose oxidase method. Preliminary immobilization for 2 hours removed the increase in the blood glucose caused by the stress reaction. By the 2nd hour of immobilization in the presence of continuing stress, the blood glucose level stabilized and varied within 42 + or - 5.5 and 47 + or - 8.1 mg %. Within 2 hours after the immobilization, the differences in the blood glucose level of the rats from the control groups were statistically insignificant

Evaluation of 3D Printed Immobilisation Shells for Head and Neck IMRT

This paper presents the preclinical evaluation of a novel immobilization system for patients undergoing external beam radiation treatment of head and neck tumors. An immobilization mask is manufactured directly from a 3-D model, built using the CT data routinely acquired for treatment planning so there is no need to take plaster of Paris moulds. Research suggests that many patients find the mould room visit distressing and so rapid prototyping could potentially improve the overall patient experience. Evaluation of a computer model of the immobilization system using an anthropomorphic phantom shows that >99% of vertices are within a tolerance of ±0.2 mm. Hausdorff distance was used to analyze CT slices obtained by rescanning the phantom with a printed mask in position. These results show that for >80% of the slices the median “worse-case” tolerance is approximately 4 mm. These measurements suggest that printed masks can achieve similar levels of immobilization to those of systems currently in clinical use

Spine immobilization apparatus

The apparatus makes use of a normally flat, flexible bladder filled with beads or micro-balloons that form a rigid mass when the pressure within the bladder is decreased below ambient through the use of a suction pump so that the bladder can be conformed to the torso of the victim and provide the desired restraint. The bladder is strapped to the victim prior to being rigidified by an arrangement of straps which avoid the stomach area. The bladder is adapted to be secured to a rigid support, i.e., a rescue chair, so as to enable removal of a victim after the bladder has been made rigid. A double sealing connector is used to connect the bladder to the suction pump and a control valve is employed to vary the pressure within the bladder so as to soften and harden the bladder as desired

Effects of immobilization on spermiogenesis

The influence of immobilization stress on spermiogenesis in rats was investigated. After 96 hour immobilization, histological changes began to manifest themselves in the form of practically complete disappearance of cell population of the wall of seminiferous tubule as well as a markedly increased number of cells with pathologic mitoses. Enzymological investigations showed various changes of activity (of acid and alkaline phosphatase and nonspecific esterase) in the 24, 48, and 96 hour immobilization groups

Cancer biomarkers detection using microstructured protein chip: implementation of customized multiplex immunoassay

Protein chips have demonstrated to be a sensitive and low cost solution to identify and detect tumor markers. However, efficient multiparametric analysis remains a challenge due to protein variability. Crucial parameters are the design of stable and reproducible surfaces which maintain biological activity of immobilized proteins, and immobilization conditions (buffer, pH, concentration). We have developed and characterized various surface chemistries for the immobilization of anti-tumor antigen antibodies onto microstructured glass slides. The effect of surface properties and antibody immobilization conditions was evaluated on the detection of tumor antigens involved in colorectal cancer. Experimental results demonstrated that each antibody displays variable biological activities depending on the surface chemistry and on the immobilization procedure. Under optimized conditions, we can reach a limit of detection in tumor antigen as low as 10 pM. Our microstructured chip offers the possibility to implement a customized multiplex immunoassay combining optimal immobilization condition for each antibody on the same chip

Role of immobilization of irradiated rats in the protective effect of bone marrow shielding

Rats were exposed to X-radiation to study the influence of immobilization and shielding of part of bone marrow during exposure on survival. It is concluded that (1) the beneficial effect of the stress factor (created by the immobilization of rats during exposure) can aggregate with the effect of bone marrow shielding and, under certain conditions, imitate the latter; and (2) the probability of the protective effect of immobilization should be taken into account when assessing the influence of bone marrow shielding

Immobilization of lactase to Perloza cellulose resins : a thesis was presented in partial fulfilment of the requirements for the degree of Master of Science in Chemistry at Massey University

A bead cellulose matrix, Perloza, was chemically modified by two attachment chemistries to prepare inexpensive resins for immobilization of lactase. A commercial product, the base-activated matrix Eupergit C was studied for comparison. Three types of Perloza (Perloza 100 MT, Perloza 200 MT, Perloza 500 TM) were activated by epichlorohydrin (ECH) to achieve different activation levels. The best result for lactase immobilization was gained at low activation level (activated at 2% NaOH) for two attachment chemistries. The first attachment chemistry studied was that lactase immobilized directly to ECH activated Perloza. The second chemistry again used ECH activation and followed by attachment of the 6-amino caproic acid (ACA) spacer arm and then the lactase. In the first chemistry, Perloza 100-ECH-Lactase obtained the highest activity 11.4 NLU/g (wet resin) over Perloza 200-ECH-Lactase and Perloza 500-ECH-Lactase (40 hours immobilization). In the second chemistry, Perloza 200-ECH-ACA-Lactase retained the highest activity 30.9 NLU/L (wet resin) over Perloza 100-ECH-ACA-Lactase and Perloza 500-ECH-ACA-Lactase. Overall the best results were obtained for the ECH-ACA resins. This best of these results showed about 3 times better immobilization than without ACA spacer arm. The activity of immobilized lactase on Eupergit C obtained was 124~131.3 NLU/g (wet resin) for 24 hours immobilization. Although this result is about four times greater than Perloza, Perloza is a much cheaper matrix. In the storage stability studies, both Perloza and Eupergit C immobilized lactase showed a sharp drop in activity initially within 1 day, then activity loss leveled out. Perloza 200-ECH-ACA-Lactase retained 82% of its original activity after 9 days storage. However, Eupergit-Lactase only retained 39% of its original activity after the same storage period. This result indicated that Perloza 200-ECH-ACA-Lactase may possess much better storage stability than that of Eupergit-Lactase. Studies on the inter-relationships between pH. temperature and Perloza immobilized lactase using the substrate (ONPG) indicated that maximum hydrolysis was attained at pH 6.5-7.2 and over a temperature range of 30-42°C. No shift in the pH and temperature optima in comparison to free enzyme was observed as a result of the process of immobilization of lactase on Perloza for both attachment chemistries. The pH-activity curve of Eupergit-Lactase shifted towards more acidic pH values in the pH optimum in comparison to free lactase. The temperature optimum of Eupergit-Lactase shifted towards higher temperature compared to free lactase. This study showed that Perloza has potential for the large scale use as a matrix of lactase immobilization

Histological and compositional responses of bone to immobilization and other experimental conditions

Histological techniques were utilized for evaluating progressive changes in tibial compact bone in adult male monkeys during chronic studies of immobilization-associated osteopenia. The animals were restrained in a semirecumbent position which reduces normally occurring stresses in the lower extremities and results in bone mass loss. The longest immobilization studies were of seven months duration. Losses of haversian bone tended to occur predominatly in the proximal tibia and were characterized by increased activation with excessive depth of penetration of osteoclastic activity. There was no apparent regulation of the size and orientation of resorption cavities. Rapid bone loss seen during 10 weeks of immobilization appeared to be due to unrestrained osteoclastic activity without controls and regulation which are characteristic of adaptive systems. The general pattern of loss persisted throughout 7 months of immobilization. Clear cut evidence of a formation phase in haversian bone was seen only after two months of reambulation