Artificial cells, blood substitutes, and immobilization biotechnology最新文献

After peripheral nerve injury, axons often project sprouts from the node of Ranvier proximal to the damage site. It is well known that one parent axon can sprout and maintain several regenerating axons. If enough endoneurial tubes in the distal stump are present for the regenerating axons to grow along, then the number of mature myelinated nerve fibers in the distal stump will be greater than the number in the proximal stump. "Multiple regeneration" is used to describe this phenomenon in the peripheral nerve. According to previous studies, a prominent nerve containing many axons can be repaired by the multiple regenerating axons sprouting from another nerve that contains fewer axons. Most peripheral nerves contain a mixture of myelinated motor and sensory axons as well as unmyelinated sensory and autonomic axons. In this study, a multiple regeneration animal model was developed by bridging the proximal common peroneal nerve with the distal common peroneal nerve and the tibial nerve. Differences in the multiple regeneration ratio of motor and sensory nerves were evaluated using histomorphometry one month after ablating the dorsal root ganglion (DRGs) and ventral roots, respectively. The results suggest that the motor nerves have a significantly larger multiple regeneration ratio than the sensory nerves at two different time points.

A biocompatible moist system was developed for effective and complete wound healing. Optimized PLGA microspheres of gentamicin (GM) and serratiopeptidase (STP) were incorporated into PVA-gelatin slurry and casted into films to prepare multiphase hydrogel. The prepared system was characterized by in vitro and in vivo studies. Results revealed the uniform dispersion of microspheres in three-dimensional matrix of the hydrogel. The in vitro release data showed a typical biphasic release pattern. All parameters such as wound contraction, tensile strength, histopathological and biochemical parameters were observed significant (p < 0.05) in comparison to the control group. Results suggested an accelerated re-epithelialization with minimum disturbance of wound bed.

In this study, a novel amperometric glucose biosensor was developed by immobilizing glucose oxidase (GOX) by cross-linking via glutaraldehyde on electrochemically polymerized polypyrrole-poly(vinyl sulphonate) (PPy-PVS) films on the surface of a platinum (Pt) electrode. Electropolymerization of pyrrole and poly(vinyl sulphonate) on the Pt surface was carried out with an electrochemical cell containing pyrrole and poly(vinyl sulphonate) by cyclic voltammetry between -1.0 and + 2.0 V (vs.Ag/AgCl) at a scan rate of 50 mV/s upon the Pt electrode. The amperometric determination was based on the electrochemical detection of H(2)O(2) generated in enzymatic reaction of glucose. Determination of glucose was carried out by the oxidation of enzymatically produced H(2)O(2) at 0.4 V vs. Ag/AgCl. The effects of pH and temperature were investigated and optimum parameters were found to be 7.5 and 65°C, respectively. The effect of working potential was investigated and optimum potential was determined to be 0.4 V. The operational stability of the enzyme electrode was also studied. The response of the PPy/PVS-GOX glucose biosensor exhibited good reproducibility with a relative standard deviation (RSD) of 2.48%. The glucose biosensor retained 63% of initial activity after 93 days when stored in 0.1 M phosphate buffer solution of pH 7.5 at 4°C. With the low operating potential, the biosensor demonstrated little interference from the possible interferants.

It is necessary to remove residual leukocytes to prevent the blood transfusion-related adverse reactions. This paper describes a facile approach for the surface modification of commercial PBT nonwoven fabrics (PBTNF), used for blood filtration, followed by immobilizing polyvinylpyrrolidone (PVP). The whole blood filtration results revealed that the five types of PBTNF-PVPs' leucocytes retention rates and erythrocyte recovery rates increased to 96% and 92% compared with the untreated PBTNF. The blood compatibilities results indicated that PVP modified PBTNFs have good blood compatibility, suggesting that PVP-modified PBTNF is a very promising blood filter for selective removal of leukocytes.

The simultaneous production production of superoxide (SOD) and catalase (CAT) from Rhodotorula glutinis was studied. The effects of temperature, initial medium pH, and carbon source on the enzyme activities were investigated. Temperature and carbon sources were found to have significant effects on the enzyme activities. 10°C provided the highest specific CAT and SOD activities as 22.6 U/mg protein and 170 U/mg protein, respectively. Glycerol was found to be the best carbon source for enzyme activities, providing 113 U/mg protein for CAT and 125 U/mg protein for SOD, which were also the highest activities obtained in the present study.

In this investigation, a new design based on a PANDA ring resonator as an optical trapping tool for tangle protein, molecular motor storage, and delivery is proposed. The optical vortices are generated and the trapping mechanism is controlled in the same way as the conventional optical tweezers. The trapping force is produced by a combination of the gradient field and scattering photons. The required molecular volume is trapped and moved dynamically within the molecular network. The tangle protein and molecular motor can be transported and delivered to the required destinations for Alzheimer's diagnosis by molecular buffer and bus network.

Optical vorticesare generated and controlled to form trapping tools in the same way as optical tweezers. By using the intense optical vortices generated within the PANDA ring resonator, the required atoms/molecules can be trapped and moved (transported) dynamically within the wavelength router or network. The advantage of the proposed system is that a transmitter and receiver can be formed within the same system, which is available for atoms/molecules storage and transportation based on methods that have been proposed to deliver drugs into cells for specific diagnosis.

During the process of peripheral nerve regeneration, a single neuron can regenerate and maintain more than one collateral in a regenerative distal stump. Furthermore, some of the new shoots can mature gradually through remyelination and grow into the remote target organ to play a physiological function. Our study found that when neonatal nerve fibers are subjected to a second injury, the regenerative distal stump can regenerate and maintain more than one collateral in the second regenerative distal stump. The neonatal nerve contributed to the functional recovery of the nerve, but the restoration of nerve function was not complete.

Paraoxonase was covalently immobilized onto a glutaraldehyde containing amino group functionalized chitosan surface by chemical immobilization at pH 8.0. The amount of covalently bound hPON1 was found to be 32 mg/10 chitosan beads. The properties of immobilized enzyme were investigated and compared to those of free enzyme. The effects of various parameters such as pH, temperature, heat, and storage stability on immobilized enzyme were investigated. Kinetic parameters of the immobilized enzyme were also evaluated. Thermal and storage stability experiments were carried out. It was observed that the immobilized enzyme had longer storage stability and retained 50 % of its initial activity during 26 days.

This study is related to the preparation of lysozyme-imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-(L)-tyroptophan methylester) [nano-MIP] nanoparticles for purification of lysozyme. Nano-MIP particles were found to be 261 nm in diameter with a surface area of 1648 m(2)/g. According to the elemental analysis results, the particles contained 0.85 μmol MATrp/g polymer. The maximum lysozyme adsorption capacity was 1182.8 mg/g. Adsorbed lysozyme was desorbed with 94% recovery. It was observed that after five adsorption-desorption cycles there was no significant loss in adsorption capacity. In order to show the selectivity of the Lys-MIP nanoparticles, adsorption of lysozyme, bovine serum albumin (BSA), and cytochrome c were investigated.