Qing Shan Liu

Alpha-Glucosidase Immobilization Based on PMMA/Chitosan Core-Shell Microparticles

Objective To obtain immobilized alpha-glucosidase with good biological activity and improve the utilization rate of alpha-glucosidase. Methods Prepare the core-shell microparticles consisting of poly (methyl methacrylate) (PMMA) cores surrounded by various of chitosan shells, induced by tert-butylhydroperoxide (TBHP). Then fixed the alpha-glucosides N-terminal onto the carriers and studied the optimum immobilization conditions and the property of alpha-glucosidase immobilized.Result Immobilized α-glucosidase enzyme pH stability was higher than the free. In particular, the relative enzyme activity were maintained at 80% in the range of pH4.5 ~ 6.5. Immobilized α-glucosidase optimum temperature is 60 °C, the optimum temperature of the free enzyme is 50 °C. Conclution These Alpha-glucosidase Immobilization can be used as biopolymer and biomaterials in the pharmaceutical and medical application fields.

A Novel Method for Preparing the Surface Molecularly Imprinted Polymers to Target Isolate Ginsenoside Rg1 and its Analogues

To establish a novel method for preparing molecularly imprinted polymers for ginsenoside Rg1 with better character contrast to previous studies, we have prepared novel surface molecular imprinted polymers (S-MIPs) using ginsenoside Rg1 as the template molecule, Acrylamide (AM) as the functional monomer, and silica gel as the carrier. The morphology of S-MIPs was characterized by scanning electron microscope (SEM) and its static adsorption capacity was measured by the Scatchard equation.

The Characterization of Chitosan Nanoparticles by Raman Spectroscopy

To study the performance of chitosan nanoparticles systematically, we characterized MMA, chitosan and synthesized chitosan nanoparticles by Raman spectroscopy. Through analyzing the characteristic peaks of each substance, we found MMA grafted chitosan by opening its carbon-carbon double bond. So Raman spectroscopy is a very effective way in terms of the characterization of nanomaterials .

Preparation and Properties of Ginsenoside Rg1 Molecularly Imprinted Polymers

Molecularly imprinted polymers (MIPs) were prepared by precipitation polymerization with ginsenoside Rg1 as the template molecule. The morphology of MIPs was characterized by scanning electronmicroscope (SEM) and its static adsorption capacity was measured by the Scatchard equation. Scatchard analysis revealed that the homogeneous binding sites were formed in the polymers. The application of MIPs with high affinity toward the template molecule might offer a novel method for the enrichment and determination of active compounds in the traditional herbal medicine.

Preparation and Application of Picroside II Molecularly Imprinted Ploymer for TCM Researching

PicrosideⅡ, one of the most effective components extracted from picrorhiza, has been reported with neuronal protective activity. To isolate the picroside Ⅱ and similar structure moleculars from picrorhiza effectively, molecularly imprinted polymer (MIP) was prepared by precipitation polymerization with Picroside Ⅱ as template molecule and TRIM as cross-linkers. The MIP was with high affinity and excellent stereo-selectivity toward Picroside Ⅱ and similar structure molecular. The purity of picroside is 70% of target sample. This research might offer a novel method for the enrichment and determination of target compounds from the Traditional Chinese Medicine. A model of middle cerebral artery occlusion and reperfusion (MCAO/R) in rats was used to determine the protective effects of Picroside II sample of this experiment on cerebral ischaemia/reperfusion in vivo. Results indicate the picroside II sample can protect neurons against acute ischemic stroke injury, and the neurological deficit scores of dosage group is lower than that of model group.

Molecularly Imprinted Solid-Phase Extraction: Extraction of Traditional Chinese Medicine Active Ingredients

Molecular imprinting technology (MIT) is a developing technique with high recognition which is just like the recognition between enzymes and antibodies in the organism. Molecularly imprinted polymers (MIPs), synthetic materials obtained using the imprinting technology, have played a huge advantage and been used in many fields. Especially, MIPs have been applied to the extraction and separation of analytes as the selective adsorbent of solid-phase extraction (SPE), which is known as molecularly imprinted polymer solid-phase extraction (MISPE) in recent years. In the present review, the methodology of MIPs preparation and evaluation are explained. Moreover, recent great developments of SPE and MISPE are discussed, and the potential application of MISPE in extraction of traditional Chinese medicine (TCM) active ingredients are also presented briefly.

Recombinant Human Ciliary Neurotrophic Factor Protects MCAO/R Rat Brain against Neuronal Degeneration and Apoptosis by Regulating NOS Expression

To research the effects and mechanisms of recombinant human ciliary neurotrophic factor (rhCNTF) on ischemia/reperfusion in vivo and in vitro, rhCNTF was biosynthesized, and ischemia/reperfusion-like models were used. Protection by rhCNTF was studied at the in vivo level using a model of middle cerebral artery occlusion and reperfusion (MCAO/R) in rats. RhCNTF was administrated just before reperfusion. RhCNTF markedly increased animal viability, decreased infarct volumes and neurological deficit scores. Primary cortical neuronal cultures were subjected to oxygen-glucose deprivation/reoxygenation, and treated with rhCNTF prophylactically. Results indicated that neuronal survival rates were increased, LDH release was decreased and lose of neurite length were alleviated in rhCNTF group, and this protection was associated with nerotrophic effect, nitric oxide and neuronal nitric oxide synthase (nNOS) and inducible NOS (iNOS). The data suggest that rhCNTF may be a good therapeutic reagent to reduce cerebral ischemia/reperfusion injury, and may act by NOS regulation.

Preparation and Characterization of Graft Copolymerization of Methyl Methacrylate onto Chitosan

To prepare and optimize core-shell nanoparticles consisting of poly (methyl methacrylate) (PMMA) with tert-butylhydroperoxide (TBHP) as an initiator. Methods The core-shell nanoparticles consisting of poly (methyl methacrylate) (PMMA) cores surrounded by various of chitosan shells, induced by tert-butylhydroperoxide (TBHP) solution. The average particle diameter and zeta potential of chitosan nanoparticles were determined by Zetasizer nanoanalyzer.Atomic force microscope was used to analyse core-shell nanoparticles morphology . Results The concentrations of chitosan and initiator tert-butylhydroperoxide (TBHP) and amounts of monomer methyl methacrylate (MMA),reaction time were effects on the nanoparticle size and grafting efficiency. The optimal conditions as follows: 0.25g in 47mL 1% acetic acid solution, tert-butylhydroperoxide (TBHP) 0.3mL, methyl methacrylate (MMA) 1g, reaction time 1.5 h and reaction temperature was at 80°C. Conclusion CS-g-PMMA nanoparticles could be successfully prepared by polymerizing MMA onto CS using tert-butylhydroperoxide as an initiator.

A Novel Method for Prepairing Higher Performance Picroside I Surface Molecularly Imprinted Polymers for TCM Research

To establish a novel method for preparing molecularly imprinted polymers for Picroside I with better performance on TCM research contrast to previous studies, we have prepared novel surface molecular imprinted polymers (S-MIPs) using Picroside I as the template molecule, Acrylamide (AM) as the functional monomer, and silica gel as the carrier. The morphology of S-MIPs was characterized by scanning electron microscope (SEM) and its static adsorption capacity was measured by the Scatchard equation.

Preparation of Chitosan/TPP Nanoparticles Used as Carrier in Enzyme Immobilization

This work investigated the preparation of chitosan nanoparticles used as carriers for immobilized enzyme. Methods The nanoparticles were prepared by ionotropic gelation method. Response surface methodology was used in the preparation of nanoparticles. The morphologic characterization of chitosan nanoparticles was evaluated by scanning electron microscope and atomic force microscope. Results Using an appropriate experimental design, we have studied the significant influence factors (pH of the solution, concentrations of the chitosan , ratios of components) in the preparation of chitosan/triphosphate (TPP) nanoparticles.