Ancient DNA and multimethod dating confirm the late arrival of anatomically modern humans in southern China.

The expansion of anatomically modern humans (AMHs) from Africa around 65,000 to 45,000 y ago (ca. 65 to 45 ka) led to the establishment of present-day non-African populations. Some paleoanthropologists have argued that fossil discoveries from Huanglong, Zhiren, Luna, and Fuyan caves in southern China indicate one or more prior dispersals, perhaps as early as ca. 120 ka. We investigated the age of the human remains from three of these localities and two additional early AMH sites (Yangjiapo and Sanyou caves, Hubei) by combining ancient DNA (aDNA) analysis with a multimethod geological dating strategy. Although U-Th dating of capping flowstones suggested they lie within the range ca. 168 to 70 ka, analyses of aDNA and direct AMS 14C dating on human teeth from Fuyan and Yangjiapo caves showed they derive from the Holocene. OSL dating of sediments and AMS 14C analysis of mammal teeth and charcoal also demonstrated major discrepancies from the flowstone ages; the difference between them being an order of magnitude or more at most of these localities. Our work highlights the surprisingly complex depositional history recorded at these subtropical caves which involved one or more episodes of erosion and redeposition or intrusion as recently as the late Holocene. In light of our findings, the first appearance datum for AMHs in southern China should probably lie within the timeframe set by molecular data of ca. 50 to 45 ka.

Small Interfering RNA Targeting DMP1 Protects Mice Against Blood-Brain Barrier Disruption and Brain Injury After Intracerebral Hemorrhage.

Dentin matrix protein 1 (DMP1) is an extracellular matrix phosphoprotein that is known to facilitate mineralization of collagen in bone and promote osteoblast/odontoblast differentiation. Blood-brain barrier (BBB) disruption is the major pathogenesis in secondary brain injury after intracerebral hemorrhage (ICH). This study aimed to investigate the expression pattern of DMP1 in the mouse brain and explore the role of DMP1 in BBB disruption and brain injury in a mouse model of ICH. Mice were subjected to autologous blood injection-induced ICH. Immunofluorescence staining, western blot analysis, neurobehavioral tests, brain water content measurements, Evans blue permeability assay, and transmission electron microscopy were performed. Small interfering RNA targeting DMP1 (DMP1 siRNA) was administered at 72 h prior to ICH. Results showed that DMP1 is expressed extensively in the mouse brain, and is upregulated in the ICH model. Administration of DMP1 siRNA effectively ameliorated BBB disruption, attenuated brain edema, and improved neurological function after ICH. Moreover, the expression of zonula occludens-1 (ZO-1) and occludin were upregulated, and matrix metalloproteinase-9 (MMP-9) was downregulated in the ICH model. DMP1 siRNA administration reversed the expression of ZO-1, occludin, and MMP-9. These results demonstrated that DMP1 upregulation plays an essential role in inducing BBB disruption and brain injury after ICH. The inhibition of DMP1 could be a potential therapeutic strategy for ICH treatment.

Bone-targeting drug delivery system of biomineral-binding liposomes loaded with icariin enhances the treatment for osteoporosis.

BACKGROUND: Osteoporosis is a bone-incapacitating malady and it is characterized by obvious bone mass loss and bone microarchitecture deterioration. Current treatments for osteoporosis have many limitations, including the non-obvious therapeutic effect and long-term safety issues. Icariin is a pharmacologically active flavonoid glycoside, which shows potential application in treatment of osteoporosis. But its clinical application is limited by the inherent disadvantages such as poor water solubility, first pass effect after oral administration, and low bioavailability. Moreover, due to lack of targeting ability, icariin cannot accumulate at the local diseased region to provide early protection from fractures. To solve the application problems of icariin and enhance its therapeutic effects on osteoporosis, this work aimed to design a targeting drug delivery system of biomineral-binding liposomes (BBL) mediated by pyrophosphate ions. RESULTS: Biomineral-binding liposomes enhanced the binding ability of liposomes with hydroxyapatite particles. It increased the serum level of alkaline phosphatase and reduced that of tartrate-resistant acid phosphatase 5b. Meanwhile, BBL increased the mechanical strength of femoral midshaft, preserving the trabecular bone microarchitecture. Moreover, BBL could initiate bone turnover/remodeling of rats with osteoporosis. CONCLUSIONS: This drug targeting delivery system of BBL loading with icariin showed more therapeutic advantages than the free icariin for the treatment of osteoporosis, which may be a kind of valid candidate in future osteoporosis therapy.

Spatial distribution and vertical characteristics of microplastics in the urban river: The case of Qinhuai River in Nanjing, China.

Microplastics (MPs) are emerging as global environmental pollutants, significantly influencing the safety of city rivers. This study investigated six sampling sites in the Qinhuai River of Nanjing, which explored the distribution and characteristics of MPs and the microbial structure in 2023. The studied river contained various levels of MPs with average concentrations of 667.68 items/L, whose abundance firstly decreased midstream and then increased downstream. The MPs abundance upstream was higher in surface water column, microplastics midstream and downstream accumulated more in deep water column. Black and blue are prevalent in the color distribution, while the polymers of PC, PP and PS changed with increasing depth, with a proportion of 74 % âˆ¼ 97 % in the dominant shapes of granules. Furthermore, the water with higher MPs may stimulate the growth of MPs-related bacteria in sediments, including the genus of Pseudoxanthomonas and Dechloromonas. Our research will provide constructive support for enhancing urban river management strategies.

Investigation of microplastics in urban rivers of Eastern China in summer: abundance, characteristics and ecological risk assessment.

Microplastics (MPs) are increasingly becoming recognized as worldwide environmental contaminants, exerting a substantial impact on the safety of city rivers. This study explored the abundance and characteristics of MPs in summer 2023, including June and August, representing plum rain and typhoon rain seasons. The Qinhuai River exhibits more spatial fluctuations in six sampling sites with average concentrations of 470 ± 119.56 items per L, and the abundance increases with the water flows in the river. Downstream had the highest MP abundance of 484 ± 121.34 items per L, which were positive with the concentration of suspended solids (SS). Transparent and green MPs were more even in the sampling sites, and the shapes of fragments were predominant in the summer. Interestingly, the proportion of fiber and small-sized (38-75 µm) microplastics was predominant in the plum rain seasons, while the percentage of large-sized (270-5000 µm) and polymers of PE occurred in the typhoon rain seasons. The index of hazard scores of plastic polymers (H) revealed that the studied river had a severe pollution level (IV), which was highly influenced by PVC and PC. Besides, the pollution load index PLI value of different rain seasons was slightly polluted (I), while the PLI in autumn rain seasons was relatively higher than that in other seasons due to the higher variance of MPs. Therefore, the ecological risk of microplastics of PVC and PC in the Qinhuai River during varying seasons should be seriously considered. Our research is expected to provide valuable assistance in improving the management of urban rivers.

A multimode biosensor based on prussian blue nanoparticles loaded with gold nanoclusters for the detection of aflatoxin B1.

Herein, a novel fluorescent/colorimetric/photothermal biosensor is proposed for aflatoxin B1 (AFB1) detection in food based on Prussian blue nanoparticles (PBNPs) (∼50 nm), gold nanoclusters (AuNCs), and an aptamer (Apt) within three hours. Briefly, a multifunctional compound, namely PBNPs-PEI@AuNCs, was synthesized from PBNPs as the loading carrier, polyethyleneimine (PEI) as the cross-linking agent, and AuNCs directly combined on the surface of PBNPs. The AFB1 Apt was then modified on the PBNPs-PEI@AuNCs to form a PBNPs-PEI@AuNCs-Apt probe, whereby when AFB1 is present, AFB1 is specifically captured by the probe. Meanwhile, the MNPs@antibody was also introduced to capture AFB1, thereby forming a "sandwich" structure compound. After magnetic separation, high temperature was applied to this "sandwich" structure compound to induce the denaturation of the Apt. Then the fluorescent/colorimetric/photothermal signals were collected from the PBNPs-PEI@AuNCs@Apt to give information on its related condition. The detection limits of the biosensor were 0.64 × 10-14, 0.96 × 10-14, and 0.55 × 10-12 g mL-1 for the three signals, which were outputted independently and could be verified with each other to ensure the accuracy of the results. Moreover, the colorimetric and photothermal strategies with this probe do not require large-scale instruments, providing a promising choice for achieving the rapid field detection of AFB1.

Effects of macrophytes on micro - And nanoplastic retention and cycling in constructed wetlands.

Macrophytes play the important roles in purifying pollutants of constructed wetlands (CWs), while their effects on CWs exposed to micro/nano plastics are not clear. Therefore, planted and unplanted CWs were established to reveal the impacts of macrophytes (Iris pseudacorus) on the overall performance of CWs under polystyrene micro/nano plastics (PS MPs/NPs) exposure. Results showed that macrophytes effectively enhanced the interception capacities of CWs to PS NPs, and significantly promoted the removal of nitrogen and phosphorus after exposed to PS MPs/NPs. Meanwhile, macrophytes improved the activities of dehydrogenase, urease, and phosphatase. Sequencing analysis showed that macrophytes optimized the composition of microbial communities in CWs and stimulated the growth of functional bacteria involved in nitrogen and phosphorus transformation. Moreover, macrophytes further altered the absolute abundance of nitrogen transformation functional genes (amoA, nxrA, narG and nirS). Functional annotation analysis revealed that macrophytes promoted metabolic functions such as Xenobiotics, Amino acids, Lipids metabolism and Signal transduction, ensuring the metabolic balance and homeostasis of microbes under PS MPs/NPs stress. These results exhibited profound implications for the comprehensive evaluation on the roles of macrophytes in CWs for treating wastewater containing PS MPs/NPs.

Synthesis of cationic polymer decorated with halogen for highly efficient trapping 99TcO4-/ReO4.

The elimination of anion is of great importance from radioactive nuclear waste containing 99TcO4- by rationally designing anion-scavenging materials with high density of charge and more accessible adsorption sites. Herein, a tailor-made cationic organic polymer with donor-acceptor (D-A) structure, namely TrDCPN, was successfully synthesized by rationally modifying the benzimidazole unit for efficient trapping the perrhenate (ReO4-) as a 99Tc surrogate. Systematic control of the skeleton affect enables the material to integrate a variety of features, surmounting the long-term challenge of 99TcO4-/ReO4- remediation under extreme conditions of high acid/base and high ionic strength. Furthermore, the TrDCPN shows excellent affinity toward ReO4- in the existence of large excess of competitive anions (SO42-, NO3- and PO43-etc.) as well as promising reusability for trapping ReO4-. The excellent stability and separation were derived from the introduction of large conjugated modules, triazine core and hydrophobic. More importantly, the synthetic cationic organic polymer with D-A feature was first proved that the introduction of halogen can effectively enhance the backbone charge, and increase the adsorption capacity by synergy of ion exchange, electrostatic interaction and δ hole-anion interaction. The adsorption capacity of TrDCPN can be up to 420.3 mg/g and reach equilibrium within 20 min. It is noteworthy that TrDCPN successfully immobilizes ReO4- from simulated Hanford waste with a high separation efficiency of 93 %, providing a new paradigm for material design to dispose of the problem of radioactive pollutants in the environment.

Comprehensive metagenomic and enzyme activity analysis reveals the negatively influential and potentially toxic mechanism of polystyrene nanoparticles on nitrogen transformation in constructed wetlands.

The widespread use of nanoplastics inevitably leads to their increasing emission into constructed wetlands (CWs). However, little is known about the impacts of nanoplastics on nitrogen transformation in CWs. In this study, the influence of polystyrene nanoparticles (PS NPs), one of the most widely used plastics, on the nitrogen transformation in CWs was comprehensively investigated, and the influential and toxic mechanism was evaluated through metagenomic analysis (DNA level) and key enzyme activities (protein level) related to N-transformation metabolism and antioxidant systems. The results showed that over 97% of PS NPs were retained in CWs, and the biofilm of sand was the main sink of PS NPs. Exposure to 1 and 10 mg/L PS NPs suppressed the nitrogen transformation, causing a certain degree of inhibition in TN removal, especially in the relatively short term of the exposure experiment (p < 0.05). At the protein level, 1 and 10 mg/L PS NPs negatively affect enzyme activities involved in denitrification (nitrate reductase and nitrite reductase) and electron transport system activity (ETSA). In contrast, 10 mg/L of PS NPs significantly suppressed the activities of nitrifying enzymes (ammonia monooxygenase, hydroxylamine dehydrogenase and nitrite oxidoreductase), whereas 1 mg/L PS NPs showed no impacts on nitrifying enzymes. Metagenomic analysis further certified that PS NPs restrained the relative abundances of genes involved in nitrogen transformation including nitrification and denitrification biochemical metabolisms (the electron production, electron transport and electron consumption processes). It also indicated that PS NPs could affect nitrogen transformation by reducing the abundance of genes for electron donor and ATP production involved in carbon metabolism (glycolysis and tricarboxylic acid cycle metabolism). In our study, the potential toxic mechanisms of PS NPs attributed to over production of reactive oxygen species and variations of antioxidant systems in macrophytes and microorganisms. These results provided valuable information for evaluating the impacts of PS NPs on CWs and arouse more attention to their impacts on the global geochemical nitrogen and carbon cycles.

Simultaneous saccharification and ethanol fermentation at high corn stover solids loading in a helical stirring bioreactor.

The higher ethanol titer inevitably requires higher solids loading during the simultaneous enzymatic saccharification and fermentation (SSF) using lignocellulose as the feedstock. The mixing between the solid lignocellulose and the liquid enzyme is crucially important. In this study, a bioreactor with a novel helical impeller was designed and applied to the SSF operation of the steam explosion pretreated corn stover under different solids loadings and different enzyme dosages. The performances using the helical impeller and the common Rushton impeller were compared and analyzed by measuring rheological properties and the mixing energy consumption. The results showed that the new designed stirring system had better performances in the saccharification yield, ethanol titer, and energy cost than those of the Rushton impeller stirring. The mixing energy consumption under different solids loadings and enzyme dosages during SSF operation were analyzed and compared to the thermal energy in the ethanol produced. A balance for achieving the optimal energy cost between the increased mixing energy cost and the reduced distillation energy cost at the high solids loading should be made. The potentials of the new bioreactor were tested under various SSF conditions for obtaining optimal ethanol yield and titer.

Responses of Low-Quality Soil Microbial Community Structure and Activities to Application of a Mixed Material of Humic Acid, Biochar, and Super Absorbent Polymer.

Low-quality soil for land reuse is a crucial problem in vegetation quality and especially to waste disposal sites in mining areas. It is necessary to find suitable materials to improve the soil quality and especially to increase soil microbial diversity and activity. In this study, pot experiments were conducted to investigate the effect of a mixed material of humic acid, super absorbent polymer and biochar on low-quality soil indexes and the microbial community response. The indexes included soil physicochemical properties and the corresponding plant growth. The results showed that the mixed material could improve chemical properties and physical structure of soil by increasing the bulk density, porosity, macro aggregate, and promote the mineralization of nutrient elements in soil. The best performance was achieved by adding 3 g·kg-1 super absorbent polymer, 3 g·kg-1 humic acid, and 10 g·kg-1 biochar to soil with plant total nitrogen, dry weight and height increased by 85.18%, 266.41% and 74.06%, respectively. Physicochemical properties caused changes in soil microbial diversity. Acidobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Firmicutes, Nitrospirae, Planctomycetes, and Proteobacteria were significantly positively correlated with most of the physical, chemical and plant indicators. Actinobacteria and Armatimonadetes were significantly negatively correlated with most measurement factors. Therefore, this study can contribute to improving the understanding of low-quality soil and how it affects soil microbial functions and sustainability.

Application of a combined model with seasonal autoregressive integrated moving average and support vector regression in forecasting hand-foot-mouth disease incidence in Wuhan, China.

Hand-foot-mouth disease (HFMD) is a serious public health problem with increasing cases and substantial financial burden in China, especially in Wuhan city. Hence, there is an urgent need to construct a model to predict the incidence of HFMD that could make the prevention and control of this disease more effective.The incidence data of HFMD of Wuhan city from January 2009 to December 2016 were used to fit a combined model with seasonal autoregressive integrated moving average (SARIMA) model and support vector regression (SVR) model. Then, the SARIMA-SVR hybrid model was constructed. Subsequently, the fitted SARIMA-SVR hybrid model was applied to obtain the fitted HFMD incidence from 2009 to 2016. Finally, the fitted SARIMA-SVR hybrid model was used to forecast the incidence of HFMD of the year 2017. To assess the validity of the model, the mean square error (MSE) and mean absolute percentage error (MAPE) between the actual values and predicted values of HFMD incidence (2017) were calculated.From 2009 to 2017, a total of 107636 HFMD cases were reported in Wuhan City, Hubei Province, and the male-to-female ratio is 1.60:1. The age group of 0 to 5 years old accounts for 95.06% of all reported cases and scattered children made up the large proportion (accounted for 56.65%). There were 2 epidemic peaks, from April to July and September to December, respectively, with an emphasis on the former. High-prevalence areas mainly emerge in Dongxihu District, Jiangxia District, and Hongshan District. SARIMA (1,0,1)(0,0,2)[12] is the optimal model given with a minimum Akaike information criterion (AIC) (700.71), then SVR model was constructed by using the optimum parameter (C = 100000, =0.00001, =0.01). The forecasted incidences of single SARIMA model and SARIMA-SVR hybrid model from January to December 2017 match the actual data well. The single SARIMA model shows poor performance with large MSE and MAPE values in comparison to SARIMA-SVR hybrid model.The SARIMA-SVR hybrid model in this study showed that accurate forecasting of the HFMD incidence is possible. It is a potential decision supportive tool for controlling HFMD in Wuhan, China.

Graphene enhanced transformation of lignin in laccase-ABTS system by accelerating electron transfer.

The degradation of lignin has attracted much attention since it represents approximately 30% of all non-fossil carbon sources and constitutes a sustainable bio-resource for fuels and aromatic derivatives. Here we investigated the degradation of lignin by laccase-catalysed reactions using 2,2'-Azino-bis(3-ethybenzothiazoline-6-sulfonic acid) (ABTS) as a mediator coupled with the carbon material graphene. Results indicated that there was a significant, two-fold, increase in the catalytic activity of lignin degradation in laccase-ABTS systems in the presence of graphene. Analysis suggested that the enhancement of lignin degradation could be attributed to graphene acting as an electron transfer conductor, thereby accelerating electron transfer, which facilitated the formation of intermediate oxidation states of ABTS and rendered the reactions between lignin and ABTS intermediates more efficient. This study could promote the development of novel enzymatic lignin degradation systems coupled with the carbon-based material graphene.

Adult Stem Cells and Hydrogels for Cartilage Regeneration.

Cartilage tissue engineering is emerging as a therapeutic approach for the repair and regeneration of cartilage tissue defects resulting from trauma and disease. It is still essential to explore approaches that employ combinations of ideal seed cells, biomaterials, and growth factors to repair defect areas because cartilage lacks spontaneous regenerative capabilities and traditional treatments do not fully satisfy clinical requirements. The purpose of this review is to summarize key advances in this area with an emphasis on adult stem cells because these cells possess a self-renewal ability and the potential for multi-directional differentiation when cultured under appropriate conditions, such as chondrocyte differentiation to synthesize cartilage-specific matrix proteins. Additionally, hydrogels and their synergistic action with growth factors to co-regulate cell behaviors and cartilage regeneration will be addressed. Hydrogels are three-dimensional water-swollen networks that provide a unique microenvironment to promote the chondrogenic phenotype by encapsulating cells as a functional cartilage substitute in a defect area. Ultimately, this review presents the prospect of combining adult stem cells, hydrogels, and growth factors using interdisciplinary approaches that may lead to significant breakthroughs in cartilage regeneration in the future.

Immobilization of Escherichia coli cells using porous support particles coated with cationic polymers.

The technique of cell immobilization using porous biomass support particles (BSPs), which is attractive from the point of view of simplicity and convenience, relies on the inherent ability of adhesive cells, as a consequence of their growth, to form films around the support material or the ability of flocculent cells to create flocs within the porous structure. In the present study, the immobilization of Escherichia coli cells using BSPs was investigated in shake-flask culture. The density of the cells immobilized within the BSPs was evaluated by measuring their intracellular lactate dehydrogenase (LDH) activity. Since E. coli K12 cells were not successfully retained within reticulated polyvinyl formal (PVF) resin BSPs with matrices of relatively small pores (pore diameter 60 microm), coating the surface of the BSPs with various polymers was examined as a way of promoting cell attachment. When positively charged polyamino acids such as poly-L-lysine, poly-L-arginine, poly-L-histidine, and poly-L-ornithine were adsorbed onto the particle surface, they were found to increase the immobilized cell density, while neutral and negatively charged polyamino acids including poly-L-asparagine and poly-L-glutamic acid were not effective. These results indicate that E. coli cells can be efficiently immobilized in PVF resin BSPs by electrostatic interaction between the negatively charged ions of the cell surface and the positively charged polymers adsorbed onto the BSP surface. A significantly high immobilized cell density was also achieved by coating the surface of the BSPs with the synthetic polymeric amine polyethyleneimine.

Selective Removal of Hemoglobin from Blood Using Hierarchical Copper Shells Anchored to Magnetic Nanoparticles.

Hierarchical copper shells anchored on magnetic nanoparticles were designed and fabricated to selectively deplete hemoglobin from human blood by immobilized metal affinity chromatography. Briefly, CoFe2O4 nanoparticles coated with polyacrylic acid were first synthesized by a one-pot solvothermal method. Hierarchical copper shells were then deposited by immobilizing Cu2+ on nanoparticles and subsequently by reducing between the solid CoFe2O4@COOH and copper solution with NaBH4. The resulting nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, and vibrating sample magnetometry. The particles were also tested against purified bovine hemoglobin over a range of pH, contact time, and initial protein concentration. Hemoglobin adsorption followed pseudo-second-order kinetics and reached equilibrium in 90 min. Isothermal data also fit the Langmuir model well, with calculated maximum adsorption capacity 666 mg g-1. Due to the high density of Cu2+ on the shell, the nanoparticles efficiently and selectively deplete hemoglobin from human blood. Taken together, the results demonstrate that the particles with hierarchical copper shells effectively remove abundant, histidine-rich proteins, such as hemoglobin from human blood, and thereby minimize interference in diagnostic and other assays.

Effect of a controlled-release drug delivery system made of oleanolic acid formulated into multivesicular liposomes on hepatocellular carcinoma in vitro and in vivo.

The aim of the present study was to develop a novel dosage form of multivesicular liposomes for oleanolic acid (OA) to overcome its poor solubility, prolong therapeutic drug levels in the blood, and enhance the antitumor effect on hepatocellular carcinoma. OA-encapsulated multivesicular liposomes (OA-MVLs) were prepared by a double-emulsion method, and the formulation was optimized by the central composite design. The morphology, particle size, and drug-loading efficiency of OA-MVLs were investigated. Furthermore, OA-MVLs were also characterized both in vitro and in vivo. The results showed that OA-MVLs were spherical particles with an average particle size of 11.57 µm and an encapsulation efficiency of 82.3%±0.61%. OA-MVLs exhibited a sustained-release pattern in vitro, which was fitted to Ritger-Peppas equation. OA-MVLs inhibited the growth of human HepG2 cells which was confirmed by the MTT assay and fluorescence microscopy detection. The in vivo release of OA from OA-MVLs exhibited a sustained manner, indicating a longer circulation time compared to OA solution. The in vivo toxicity study indicated that medium-dose OA-MVLs exerted no toxic effect on the hosts. Importantly, OA-MVLs suppressed the growth of murine H22 hepatoma and prolonged the survival of tumor-bearing mice. In conclusion, the poorly soluble OA could be encapsulated into MVLs to form a novel controlled-release drug delivery system. The present study may hold promise for OA-MVLs as a new dosage form for sustained-release drug delivery in cancer therapy.

Efficient reduction and pH co-triggered DOX-loaded magnetic nanogel carrier using disulfide crosslinking.

To reduce leakage on the drug-delivery pathway to minimize side effect of reduction or pH sensitive drug delivery systems, we designed a glutathione (GSH)/pH co-triggered magnetic nanogel drug delivery system for doxorubicin (DOX) based on the GSH concentration and pH difference between intracellular and extracellular environments. The introduction of superparamagnetic iron oxide nanoparticles (SPION) was intended for magnetic targeting. The magnetic DOX-loaded nanogel was then prepared by the oxidation of thiolated alginate with thiolated SPION in the presence of DOX. The nanogel size can be readily regulated in a range of 120-320 nm upon preparation conditions, with a negative surface charge of around -40 mV. Saturation magnetization was estimated at 27.4 emu/g Fe by VSM. In vitro release was conducted in simulated cancerous environment conditions such as a high GSH concentration and mild acidity. As a result, the nanogel expressed, upon dual stimuli of pH 5/10 mM GSH, significantly higher accumulative release than upon single stimulus of pH 5 without GSH or pH 7.4/10 mM GSH. In vitro cytotoxicity against HeLa cells clearly illustrated that the nanogel could effectively inhibit cell growth, and the IC50 was figured out to be 2.3 µg/mL of the nanogel, while the nanogel exclusive of DOX was nontoxic. Confocal laser scanning microscopy observation, combined with the result of Prussian blue staining, indicated that DOX was efficiently internalized into HeLa cells through endocytosis, released into the cytoplasm, and then principally entered the nuclei. The quantitative examination of the iron content revealed an exponential increase in the cellular uptake and an exponential decrease in the uptake efficiency with the fed nanogel. This drug-loaded nanogel could be a promising drug carrier for effective tumor-targeted chemotherapy.

A novel antibody immobilization and its application in immunoaffinity chromatography.

A novel antibody immobilization and its application in immunoaffinity chromatography (IAC) were presented. Using acrylamide (AM) as monomer, ethylene glycoldimethacrylate (EGDMA) as cross-linker and bulk polymerization as synthetic method, we prepared a polymer in which the Cu(II) was embedded. The Cu(II)-embedded polymer was tested for its binding with protein. It was found that Cu(II)-embedded polymer displayed a strong binding with bovine serum albumin (BSA). At 80% of methanol, no BSA was released from Cu(II)-embedded polymer. The Cu(II)-embedded polymer was then used as a novel solid support for antibody immobilization. IAC column was prepared by immobilizing polyclonal antibody (pAb) against clenbuterol (CL) on Cu(II)-embedded polymer and packing the Cu(II)-embedded polymer-pAb into a common solid phase extraction (SPE) cartridge. Under optimal extraction conditions, the IAC column was characterized in terms of maximum binding capacity for target analyte, extraction efficiency and reusability. It was revealed that, for IAC column packed with 0.1 g of solid support immobilized with antibody, the maximum capacity for CL was 616 ng; the extraction recoveries of the column for CL from three spiked food samples were 84.4-95.2% with relative standard deviation (RSD) of 9.3-15.5%; after more than 30 times repeated usage, there was not significant loss of specific recognition. The results demonstrated the feasibility of the prepared IAC column for CL extraction. The proposed antibody immobilization method exhibiting the properties of simplicity, low cost, strong binding for target analyte, no leaching of antibody, etc., would be a very useful tool applied in the field of IAC.