O2-Generation-Enhanced Responsive Starvation/Photothermal Synergistic Tumor Therapy Based on the AuNRs@MnO2@SiO2 Nanocarrier and Thermosensitive Biomimetic Camouflaging

Cancer starvation/photothermal combined tumor therapy (CST/PTT) has attracted great interest attributed to their mutual compensation and synergistically enhanced effect. However, the very low O2 supply in the tumor microenvironment (TME) greatly limits the CST efficiency of glucose oxidase (GOx). Additionally, the easy degradation in blood circulation and significant off-target effects are big challenges for clinical applications of the GOx-based CST. In this study, a drug delivery system (DDS) with specific tumor-targeted GOx delivery, near-infrared (NIR) light and TME responsive O2 generation, NIR-responsive glucose consumption, high GOx loading, and efficient NIR photothermia was developed. Positively charged AuNRs@MnO2@SiO2 nanoparticles (named AMS+ NPs) were synthesized. GOx was covalently loaded with a high loading ratio of 36.0%. Finally, a thermosensitive biomimetic hybrid membrane composed of a thermosensitive lipid (TSL) membrane, red blood cell membrane (RBCM), and 4T1 cancer cell membrane (CCM) was coated on the NPs through a double-layer strategy. The AMS+-G@TSL@[RBC-CC-TSL]M NPs consumed 32.7 times glucose at 50 °C as that at 37 °C and generated 4.9 times O2 upon NIR laser irradiation. The thermosensitive biomimetic NPs showed an efficient targeting capability to the homotypic 4T1 cancer cells/tumors accompanied by good biocompatibility, macrophage evading capability, high cancer cell cytotoxicity, and excellent antitumor efficacy. The tumor growth inhibition ratio with NIR laser irradiation reached 92.8%. The AMS+-GOx@TSL@[RBC-CC-TSL]M NPs provide a smart, efficient, safe, PTT/CST combined DDS for highly efficient tumor therapy.

pH-Sensitive Biomimetic Nanosystem Based on Large-Pore Mesoporous Silica Nanoparticles with High Hyaluronidase Loading for Tumor Deep Penetration

Loading hyaluronidase (Hyal) in a nanocarrier is a potent strategy to degrade the tumor extracellular matrix for tumor deep penetration and enhanced tumor therapy. Herein, a pH-sensitive biomimicking nanosystem with high Hyal loading, effective tumor targeting, and controllable release is constructed. Specifically, cationic mesoporous silica nanoparticles (CMSNs) with large pores 13.52 nm in diameter were synthesized in a one-pot manner by adding N-[3-trimethoxysilylpropyl]-N,N,N-trimethylammonium to a reversed microemulsion reaction system. The Hyal loading rate was as high as 19.47% owing to matched pore size and the cationic surface charge. Subsequently, a pH-sensitive biomimetic hybrid membrane (pHH) composed of pH-sensitive liposome (pHL), red blood cell membrane, and pancreatic cancer cell membrane was camouflaged on the pHL-coated and doxorubicin/Hyal-loaded CMSNs (shortened as DHCM). The DHCM@pHL@pHH is stable at neutral pH while it releases the payloads smoothly in the tumor acidic microenvironment. Consequently, it can escape from macrophage clearance, be specifically taken up by pancreatic cancer cells, and efficiently accumulate at the tumor site. More importantly, it can penetrate deeply in pancreatic tumors with a tumor growth inhibition ratio of 80.46%. The nanosystem is biocompatible and has potential for clinical transformation, and the nanocarrier is promisingly applicable as a platform for encapsulation of various macromolecules for smart and tumor-targeted delivery.

Aptamer-based technology for gastric cancer theranostics

Gastric cancer is one of the most common causes of cancer death worldwide. This cancer exhibits high molecular and phenotype heterogeneity. The overall survival rate for gastric cancer is very low because it is always diagnosed in the advanced stages. Therefore, early detection and treatment are of great significance. Currently, biomedical studies have tapped the potential clinical applicability of aptamer-based technology for gastric cancer diagnosis and targeted therapy. Herein, we summarize the enrichment and evolution of relevant aptamers, followed by documentation of the recent developments in aptamer-based techniques for early diagnosis and precision therapy for gastric cancers.

Bright, small sizes and hydro-dispersive NIR persistent luminescence nanoparticles modified with Si and amino groups for enhanced bioimaging

Near-infrared (NIR) persistent luminescence nanoparticles (PLNPs) with high brightness, small sizes, good hydro-dispersivity, and intrinsic surface-functional groups are desirable in biological applications. In this work, Cr³⁺-doped zinc gallogermanates Zn_1+xGa_2-2xGe_xO₄:Cr (ZGGC) PLNPs were hydrothermally synthesized via 3-aminopropyltriethoxysilane (APTES) as an additive, or APTES and cetyltrimethylammonium bromide (CTAB) as two co-additives. Addition of APTES not only dramatically enhances the 696 nm NIR luminescence intensity, but also obviously decreases the particle size and introduces amino groups. In particular, thex= 0.1 series ZGGC (ZGGC_0.1) with the addition of n moles equivalent APTES (ZGGC_0.1-nA) had smaller particle sizes than thex= 0.2 counterpart (ZGGC_0.2-nA). The NIR afterglow intensities increased with the APTES introduction. The ZGGC_0.2-2.5A sample (also named as ZGGC, Si, -NH₂) exhibited maximum luminescence intensities both in solid and aqueous states. With APTES, Si atom is doped and -NH₂groups are modified, the trap depth and density become larger, and the afterglow intensities and decay time are significantly enhanced. More notably, co-addition of CTAB (ZGGC_0.2-2.5A-C) (also named as ZGGC, Si, -NH₂') further enhances hydro-dispersivity and luminescence intensity, decreases particle sizes, and results in more prominent amino groups. The trap density is drastically higher than that without CTAB (i.e. ZGGC_0.2-2.5A). Change of Cr³⁺microenvironment in the crystal and more defects introduction contribute to the enhanced brightness. As expected, the ZGGC,Si,-NH₂' PLNPs possess excellent biocompatibility, deep tissue penetration and distinguished bioimaging properties, and rechargeability with orange LED light. The ZGGC,Si,-NH₂' PLNPs should provide to be an excellent nanomaterial for various functionalization and bioimaging applications.

Thermosensitive Biomimetic Hybrid Membrane Camouflaged Hollow Gold Nanoparticles for NIR-Responsive Mild-Hyperthermia Chemo-/Photothermal Combined Tumor Therapy

As an appealing biomimetic strategy for various medical applications, cell membrane coating lacks sensitive on-demand breaking capability. Herein, we incorporated thermosensitive lipid (TSL) membrane into red blood cell (RBC) and MCF-7 cancer cell (MC) hybrid membrane ([RBC-MC]M) vesicles. The [RBC-MC-TSL]M was coated onto doxorubicin (Dox)-loaded hollow gold nanoparticles to enhance chemo-/photothermal combined tumor therapy at a mild hyperthermia temperature (≤49 °C). Double-layer coating with TSL and [RBC-MC-TSL]M as the inner and outer layer, respectively, presented better antileakage and higher NIR-responsivity than single-layer coating. The Dox release ratio upon NIR laser irradiation (≤49 °C) was 74.6%, much higher than that (33.5%) without NIR laser. The nanodrug can be efficiently and specifically taken up by MCF-7 cells. In addition, the nanodrug exhibited excellent tumor-targeting property, with 4.08- and 1.12-times Dox accumulation in MCF-7 tumors compared to free Dox and [RBC-MC]M-coated counterpart, respectively. Most importantly, TSL incorporation significantly enhanced NIR-responsive antitumor efficiency, with tumor growth inhibition ratio increased from 35.1% to 48.6% after a single dose administration. Besides, the nanodrug exhibited very good biocompatibility. Camouflaging nanoparticles with the thermosensitive biomimetic hybrid membrane provides a painless and promisingly clinical-applicable approach for effective chemo-/photothermal combined mild-hyperthermia tumor therapy.

A DNAzyme-catalyzed label-free aptasensor based on multifunctional dendrimer-like DNA assembly for sensitive detection of carcinoembryonic antigen

Carcinoembryonic antigen (CEA) is an important malign tumor marker. In this study, a simple, label-free and antibody-free aptasensor was fabricated based on a multifunctional dendrimer-like DNA nanoassembly. The DNA nanoassembly was embedded with multiple G-quadruplex DNAzyme motifs and a hanging CEA aptamer motif. It was prepared from short DNA sequences by autonomous-assembly. The aptasensor was prepared simply by self-assembly of a capture DNA (cpDNA) on a gold electrode, followed by hybridization with a CEA aptamer (AptGAC-P). CEA as a model target was detected through competitive binding of CEA with AptGAC-P, exposing cpDNA to bind with the DNA nanoassembly. The detection process only contains 2 incubation steps. The high load of G-quadruplex DNAzyme motifs and their catalytic activity resulted in an amplified and label-free differential pulse voltammetry (DPV) electrochemical signal. The peak current correlated linearly with the CEA concentration, with a linear range of 2-45 ng mL^-1, and an LOD value of 0.24 ng mL^-1. The aptasensor showed high specificity and reproducibility, and retained 96.5% of detection signal intensities after 31 days of storage. The recovery rates for spiked CEA in human serum were within 100 ± 5%, and the coincidence rates for clinical human serum samples with ELISA kits were 80.7-111%. Conceivably, possessing simplicity, sensitivity, reproducibility, storage stability, and accuracy, the aptasensor should be a very prominent and applicable tool for clinical CEA detection and cancer diagnosis, and is promisingly applicable as a platform for detecting other targets of interests.

Red fluorescent nanoprobe based on Ag@Au nanoparticles and graphene quantum dots for H2O2 determination and living cell imaging

A sensitive and turn-on fluorescence nanoprobe based on core-shell Ag@Au nanoparticles (Ag@AuNPs) as a fluorescence receptor and red emissive graphene quantum dots (GQDs) as a donor was fabricated. They were conjugated together through π-π stacking between the GQDs and single-strand DNA modified at the Ag@AuNPs surface. The absorption spectrum of the receptor significantly overlapped with the donor emission spectrum, leading to a strong Förster resonance energy transfer (FRET) and thus a dramatic quenching. The sensing mechanism relies on fluorescence recovery following DNA cleavage by •OH produced from Fenton-like reaction between the peroxidase-like Ag nanocore and H₂O₂. The red emissive feature (Ex/Em, 520 nm/560 nm) provides low background in physiological samples. The •OH production, great spectrum overlapping, and red emission together contributes to good sensitivity and living cell imaging capability. The fluorescence assay (intensity at 560 nm) achieves a low detection limit of 0.49 μM H₂O₂ and a wide linear range from 5 to 200 μM, superior to most of the reported fluorescent probes. The RSD value for 100 μM H₂O₂ was 1.4%. The nanoprobe exhibits excellent anti-interferences and shows low cytotoxicity. The recovery of 100 μM standard H₂O₂ in a cancer cell lysate was 85.8%. Most satisfactorily, it can realize monitoring and imaging H₂O₂ in living cells. This study not only presents a sensitive H₂O₂ probe but also provides a platform for detecting other types of reactive oxygen species.

[Endogenous Pollution and Release Characteristics of Bottom Sediments of Hengshan Reservoir in Yixing City]

To clarify the endogenous pollution and release characteristics of the bottom sediment of Hengshan Reservoir in Yixing City, a typical section of the reservoir was sampled and analyzed. The research results show that the average concentrations of total nitrogen, total phosphorus, and organic matter in the surface sediments of Hengshan Reservoir are 2778 mg·kg^-1, 899 mg·kg^-1, and 3.1%, respectively. The endogenous pollution is serious, and the downstream sediments are highly polluted upstream of the reservoir. Phosphorus spectroscopic analysis results show that iron-bound phosphorus (Fe-P) and aluminum-bound phosphorus (Al-P) are the main bound phosphorus forms in the sediment, accounting for 28% and 39% of the total phosphorus, respectively. The average concentration of activated phosphorus in the sediment (combination of weakly adsorbed phosphorus, organic phosphorus, and iron phosphorus) is 255 mg·kg^-1, accounting for 38% of the total phosphorus. The average release rates of nitrogen and phosphorus in sediments were 18.0 mg·(m²·d)^-1 and 0.60 mg·(m²·d)^-1. The correlation analysis results show that the organic matter content of the sediment is significantly correlated with the diffusion flux of phosphate, ammonia nitrogen, and ferrous iron (P<0.05), indicating that the mineralization of organic matter in the sediment may be the main release source of nitrogen and phosphorus in the sediment influencing factors.

An enzyme-free electrochemical sandwich DNA assay based on the use of hybridization chain reaction and gold nanoparticles: application to the determination of the DNA of Helicobacter pylori

An ultrasensitive enzyme-free electrochemical sandwich DNA biosensor is described for the detection of ssDNA oligonucleotides. A DNA sequence derived from the genom of Helicobacter pylori was selected as a model target DNA. The DNA assay was realized through catching target DNA on capture DNA immobilized gold electrode; then labeling the target DNA with reporter DNA (rpDNA) and initiator DNA (iDNA) co-modified gold nanoparticles (AuNPs). The high density of iDNAs serves as one of the amplification strategies. The iDNA triggers hybridization chain reaction (HCR) between two hairpins. This leads to the formation of a long dsDNA concatamer strand and represents one amplification strategy. The electrochemical probe [Ru(NH₃)₅L]²⁺, where L stands for 3-(2-phenanthren-9-ylvinyl)pyridine, intercalated into dsDNA chain. Multiple probe molecules intercalate into one dsDNA chain, serving as one amplification strategy. The electrode was subjected to differential pulse voltammetry for signal acquisition, and the oxidation peak current at -0.28 V was recorded. On each AuNP, 240 iDNA and 25 rpDNA molecules were immobilized. Successful execution of HCR at the DNA-modified AuNPs was confirmed by gel electrophoresis and hydrodynamic diameter measurements. Introduction of HCR significantly enhances the DNA detection signal intensity. The assay has two linear ranges of different slopes, one from 0.01 fM to 0.5 fM; and one from 1 fM to 100 fM. The detection limit is as low as 0.68 aM. Single mismatch DNA can be differentiated from the fully complementary DNA. Conceivably, this highly sensitive and selective assay provides a general method for detection of various kinds of DNA. Graphical abstractSchematic representation of the detection and the amplification principles of the electrochemical sandwich DNA assay. Purple curl: Captured DNA; Green curl: Reporter DNA; Orange curl: HCR initiator DNA; Yellow solid-circle: Gold nanoparticle; H1 and H2: Two hairpin DNA; [Ru(NH₃)₅L]²⁺: Signal probe.

In silicopost-SELEX screening and experimental characterizations for acquisition of high affinity DNA aptamers against carcinoembryonic antigen

High affinity DNA aptamers against carcinoembryonic antigen were selected and verified by using anin silicoapproach and experimental characterizations.

Detection of Helicobacter pylori in dental plaque using a DNA biosensor for noninvasive diagnosis

H. pylori in dental plaque was detected with a DNA biosensor with results correlating well with the ¹³C urea breath test.

Selection, identification, and characterization of aptamers for pro-gastrin-releasing peptide (31–98), a tumor marker for small cell lung cancer

Pro-gastrin-releasing peptide (31–98) (ProGRP_31–98) is a highly reliable, sensitive, and specific tumor marker for small cell lung cancer (SCLC).

Self-assembly of a thin highly reduced graphene oxide film and its high electrocatalytic activity

A thin highly reduced graphene oxide (rGO) film was self-assembled at the dimethyl formamide (DMF)-air interface through evaporation-induced water-assisted thin film formation at the pentane-DMF interface, followed by complete evaporation of pentane. The thin film was transferred onto various solid substrates for film characterization and electrochemical sensing. UV-visible spectrometry, scanning electron microscopy (SEM), atomic force microscopy (AFM) and electrochemistry techniques were used to characterize the film. An rGO film showing 82.8% of the transmittance at 550 nm corresponds to a few layers of rGO nanosheets. The rGO nanosheets cross-stack with each other, lying approximately in the plane of the film. An rGO film collected on a glassy carbon (GC) electrode exhibited improved electrical conductivity compared to GC, with the electrode charge-transfer resistance (Rct) reduced from 31 Ω to 22 Ω. The as-formed rGO/GC electrode was mechanically very stable, exhibiting significantly enhanced electrocatalytic activity to H(2)O(2) and dopamine. Multiple layers of the rGO films on the GC electrode showed even stronger electrocatalytic activity to dopamine than that of the single rGO film layer. The controllable formation of a stable rGO film on various solid substrates has potential applications for nanoelectronics and sensors/biosensors.

Immobilization of glucose oxidase into a nanoporous TiO₂ film layered on metallophthalocyanine modified vertically-aligned carbon nanotubes for efficient direct electron transfer

Glucose oxidase (GOD) was adsorbed into a nanoporous TiO₂ film layered on the surface of an iron phthalocyanine (FePc) vertically-aligned carbon nanotube (CNT) modified electrode. A Nafion film was then dropcast on the electrode's surface to improve operational and storage stabilities of the GOD-based electrode. Scanning electron microscopy (SEM) micrographs revealed the formation of FePc and nanoporous TiO₂ nanoparticles along the sidewall and the tip of CNTs. Cyclic voltammograms of the GOD electrode in neutral PBS exhibited a pair of well-defined redox peaks, attesting the direct electron transfer of GOD (FAD/FADH₂) with the underlying electrode. The potential of glucose electro-oxidation under nitrogen was ∼+0.12 V with an oxidation current density of 65.3 μA cm(-2) at +0.77 V. Voltammetric and amperometric responses were virtually unaffected by oxygen, illustrating an efficient and fast direct electron transfer. The modification of the CNT surface with FePc resulted in a biosensor with remarkable detection sensitivity with an oxygen-independent bioelectrocatalysis. In deaerated PBS, the biosensor displayed average response time of 12 s, linearity from 50 μM to 4 mM, and a detection limit of 30 μM (S/N=3) for glucose.

Rapid discrimination of pork in Halal and non-Halal Chinese ham sausages by Fourier transform infrared (FTIR) spectroscopy and chemometrics

Rapid discrimination of pork in Halal and non-Halal Chinese ham sausages was developed by Fourier transform infrared (FTIR) spectrometry combined with chemometrics. Transmittance spectra ranging from 400 to 4000 cm⁻¹ of 73 Halal and 78 non-Halal Chinese ham sausages were measured. Sample preparation involved finely grinding of samples and formation of KBr disks (under 10 MPa for 5 min). The influence of data preprocessing methods including smoothing, taking derivatives and standard normal variate (SNV) on partial least squares discriminant analysis (PLSDA) and least squares support vector machine (LS-SVM) was investigated. The results indicate removal of spectral background and baseline plays an important role in discrimination. Taking derivatives, SNV can improve classification accuracy and reduce the complexity of PLSDA. Possibly due to the loss of detailed high-frequency spectral information, smoothing degrades the model performance. For the best models, the sensitivity and specificity was 0.913 and 0.929 for PLSDA with SNV spectra, 0.957 and 0.929 for LS-SVM with second derivative spectra, respectively.

Interfacing carbon nanotubes with living mammalian cells and cytotoxicity issues

The unique structures and properties of carbon nanotubes (CNTs) have attracted extensive investigations for many applications, such as those in the field of biomedical materials and devices, biosensors, drug delivery, and tissue engineering. Anticipated large-scale productions for numerous diversified applications of CNTs might adversely affect the environment and human health. For successful applications in the biomedical field, the issue of interfacing between CNTs and mammalian cells in vitro needs to be addressed before in vivo studies can be carried out systematically. We review the important studies pertaining to the internalization of CNTs into the cells and the culturing of cells on the CNT-based scaffold or support materials. The review will focus on the description of a variety of factors affecting CNT cytotoxicity: type of CNTs, impurities, lengths of CNTs, aspect ratios, dispersion, chemical modification, and assaying methods of cytotoxicity.

Enhancement of dopamine sensing by layer-by-layer assembly of PVI-dmeOs and Nafion on carbon nanotubes

In this study, carbon nanotubes (CNTs) were modified to further improve their performance in electrochemical sensing of dopamine (DA) levels. After a redox polymer, poly(vinylimidazole) complexed with Os(4, 4'-dimethyl- 2, 2-bipyridine)(2)Cl (termed PVI-dmeOs) was electrodeposited on multi-wall CNTs (MWCNTs), Nafion and PVI-dmeOs films were successfully layer-by-layer (LBL) assembled on the hydrophilic surface of the as-prepared PVI-dmeOs/CNTs nanocomposites through electrostatic interactions. The LBL assembly was proved by scanning electron microscopy (SEM), electrochemistry and UV-vis spectroscopy measurements. LBL assembly of Nafion/PVI-dmeOs films on CNTs significantly enhanced their linear sweep voltammetry (LSV) response sensitivity to DA, with a maximum enhancement for three Nafion/PVI-dmeOs film-modified MWCNTs. The LSV peak current density of (Nafion/PV I-dmeOs)(3)/CNT electrodes in response to 10 and 50 microM DA solutions was about 7.3 and 3.9 times those for bare CNTs. At the (Nafion/PV I-dmeOs)(3)/CNT electrodes, the limit of detection (LOD) (signal-to-noise ratio: 3) was 0.05 microM DA, the linear range was 0.1-10 microM DA (with a linear regression coefficient of 0.97) and the DA-sensing sensitivity was 8.15 microA cm( - 2) microM( - 1). The newly fabricated (Nafion/PV I-dmeOs)(3)/CNT electrodes may be developed as an ideal biosensor for direct and in situ measurement of DA levels.

Selective and sensitive electrochemical detection of glucose in neutral solution using platinum–lead alloy nanoparticle/carbon nanotube nanocomposites

Electrodeposition of Pt-Pb nanoparticles (PtPbNPs) to multi-walled carbon nanotubes (MWCNTs) resulted in a stable PtPbNP/MWCNT nanocomposite with high electrocatalytic activity to glucose oxidation in either neutral or alkaline medium. More importantly, the nanocomposite electrode with a slight modification exhibited high sensitivity, high selectivity, and low detection limit in amperometric glucose sensing at physiological neutral pH (poised at a negative potential). At +0.30 V in neutral solution, the nanocomposite electrode exhibited linearity up to 11 mM of glucose with a sensitivity of 17.8 microA cm(-2) mM(-1) and a detection limit of 1.8 microM (S/N=3). Electroactive ascorbic acid (0.1 mM), uric acid (0.1 mM) and fructose (0.3 mM) invoked only 23%, 14% and 9%, respectively, of the current response obtained for 3 mM glucose. At -0.15 V in neutral solution, the electrode responded linearly to glucose up to 5 mM with a detection limit of 0.16 mM (S/N=3) and detection sensitivity of approximately 18 microA cm(-2) mM(-1). At this negative potential, ascorbic acid, uric acid, and fructose were not electroactive, therefore, not interfering with glucose sensing. Modification of the nanocomposite electrode with Nafion coating followed by electrodeposition of a second layer of PtPbNPs on the Nafion coated PtPbNP/MWCNT nanocomposite produced a glucose sensor (poised at -0.15 V) with a lower detection limit (7.0 microM at S/N=3) and comparable sensitivity, selectivity and linearity compared to the PtPbNP/MWCNT nanocomposite. The Nafion coating lowered the detection limit by reducing the background noise, while the second layer of PtPbNPs restored the sensitivity to the level before Nafion coating.

Microelectrode array biochip: tool for in vitro drug screening based on the detection of a drug effect on dopamine release from PC12 cells

Novel, yet simple detection techniques of drug effect, including the effect of a vesicular monoamine transporter inhibitor (reserpine), a dopamine precursor (L-dopa), and a dopamine transporter inhibitor (nomifensine), on dopamine release from dopaminergic PC12 cells were developed based on a microelectrode array (MEA) biochip. Upon multi-injections of KCl solution into the culture of PC12 cells attached on a MEA biochip, the K+-stimulated dopamine release was temporally and amperometrically recorded by biochip microelectrodes. Two parameters in the recorded amperometric spectra were defined in this study: the peak current of the first KCl injection (Max1), and the steady current after the fourth KCl injection (St4). Statistically significant effects of L-dopa and reserpine were demonstrated by comparing both Max1 and St4 of the second detections in drugs with those of the control without drug treatment. The values of both Max1 and St4 in the first detections were normalized as 1. In contrast, the statistically significant effect of nomifensine was detected by comparing the ratios of St4 to Max1 in the first detections in drug with those of the control. The reason for using different analytical methods for measurements between L-dopa/reserpine and nomifensine lies in the different mechanisms of action on PC12 cells among these drugs. The novel analytical methods developed use the same detection setup and parameters, and the data analysis for the effect of drugs becomes simple. The methods hence may provide a high-throughput in vitro drug screening approach for dopamine-related psychiatric disorders.

[Protective mechanism of tianmacuzhi granules in brain]

OBJECTIVE

To provide pharmacological evidence for the protective effects of Tianmacuzhi Granules (TMC) in mouse brain in a ischemia--reperfusion model.

METHOD

Receptor binding test of NMDA receptor and M receptor in brain, GPx activity determination in brain and liver effected by different dose of TMC were performed.

RESULT

TMC could reduce the NMDA receptor activity, increase the M receptor activity and GPx activity of cerebral cortex and hippocampus tissues significantly.

CONCLUSION

TMC might antagonize ischemia-reperfusion injury of brain by reducing the glutamate neurotoxicity and increasing the function of cholinergic nerve and effects of anti-peroxidization in brain.

[Protective effect of xinxin capsule on learning and memory impairment in mice]

OBJECTIVE

To investigate the effect of Xinxin Capsule on the scopolamine or ethanol induced impairment of learning and memory retention in mice.

METHOD

Step-through and Morris Water-maze methods, wer used to the protective effect of Xinxin Capsule(0.4, 0.8, 1.6 g.kg-1, ig, 16 d) on the scopolamine or ethanol induced impairment of learning and memory retention in mice.

RESULT

The Capsule(0.8, 1.6 g.kg-1, ig,) can turn over the Scope so as to induce the impairment of learning, and the Capsule((0.4, 0.8, 1.6 g.kg-1, ig) can improve the ethanol induced impairment of memory retention in mice.

CONCLUSION

Xinxin Capsule helps regain as well as impair the learning and memory retention in mice.