Chun Mao

Improvement of hemocompatibility of polycaprolactone film surfaces with zwitterionic polymer brushes.

Polycaprolactone (PCL) has been widely adopted as a scaffold biomaterial, but further improvement of the hemocompatibility of a PCL film surface is still needed for wide biomedical applications. In this work, the PCL film surface was functionalized with zwitterionic poly(3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate) (P(DMAPS)) brushes via surface-initiated atom transfer radical polymerization (ATRP) for enhancing hemocompatibility. Kinetics study revealed an approximately linear increase in graft yield of the functional P(DMAPS) brushes with polymerization time. The blood compatibilities of the modified PCL film surfaces were studied by platelet adhesion tests of platelet-rich plasma and human whole blood, hemolysis assay, and plasma recalcification time (PRT) assay. The improvement of hemocompatibility is dependent on the coverage of the grafted P(DMAPS) brushes on the PCL film. Lower or no platelet and blood cell adhesion was observed on the P(DMAPS)-grafted film surfaces. The P(DMAPS) grafting can further decrease hemolysis and enhance the PRT of the PCL surface. With the versatility of surface-initiated ATRP and the excellent hemocompatibility of zwitterionic polymer brushes, PCL films with desirable blood properties can be readily tailored to cater to various biomedical applications.

Preparation of lotus-leaf-like polystyrene micro- and nanostructure films and its blood compatibility

The lotus-leaf-like polystyrene (PS) micro- and nanostructure film was prepared and characterised. This film reveals superhydrophobicity and good blood compatibility. The realization of this hierarchical PS nanostructure film could be important for further understanding non-wettability of biological surfaces with micro- and nanostructure and application in biomedical devices.

Preparation and evaluation of well-defined hemocompatible layered double hydroxide-poly(sulfobetaine) nanohybrids

The ability to manipulate and control the surface properties of layered double hydroxide (LDH) nanoparticles is of crucial importance in the designing of LDH-based carriers of therapeutic agents. In this work, surface-initiated atom transfer radical polymerization (ATRP) of zwitterionic 3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate (DMAPS) is first employed to tailor the functionality of LDH surfaces in a well-controlled manner and produce a series of well-defined hemocompatible hybrids (termed as LDHPS). The blood compatibilities of the modified LDH nanoparticles were investigated using coagulation tests, complement activation, platelet activation, hemolysis assay, morphological changes of red blood cells, and cytotoxicity assay. The results confirmed that the P(DMAPS) grafting can substantially enhance the hemocompatibility of the LDH particles, and the LDHPS hybrids can be used as biomaterials without causing any hemolysis. With the versatility of surface-initiated ATRP and the excellent hemocompatibility of zwitterionic polymer chains, the LDH nanoparticles with desirable blood properties can be readily tailored to cater to various biomedical applications.

Electrochemical immunosensor based on hyperbranched structure for carcinoembryonic antigen detection

Sensitive determination of carcinoembryonic antigen (CEA) is very important in clinical research and diagnosis. Herein we report the design and synthesis of a new kind of immunosensor based on the benefits of hyperbranched structure. The hyperbranched polyester was grafted to the surface of indium tin oxides glass (ITO) electrode, and the grafting processes were characterized by attentuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). After CEA and horse radish peroxidase (HRP)-labeled antibody-conjugated AuNPs (HRP-Ab2-AuNPs) bioconjugates were immobilized on the surface of the hyperbranched structure-modified electrode, the optimized conditions of the above electrode were investigated. Moreover, the analytical performance of the proposed immunosensor showed a high sensitivity, a linear range from 0.01 to 80ng/mL with a low detection limit of 2.36pg/mL, and good selectivity for CEA. The designed immunoassay system holds great potential for ultrasensitive electrochemical biosensing of other analytes.

Biocompatibility of CS–PPy nanocomposites and their application to glucose biosensor

The intrinsic properties and application potential of nanocolloids are mainly determined by size, shape, composition, and structure. In this case, a novel glucose biosensor was developed by using the chitosan-polypyrrole (CS-PPy) nanocomposites as special modified materials that coating onto the surface of glassy carbon electrode (GCE). The CS-PPy nanocomposites were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. Moreover, the interaction of CS-PPy nanocomposites with glucose oxidase (GOD) was also investigated by the combined studies with Fourier transform infrared spectroscopy (FTIR) and circular dichroism spectroscopy (CD). Due to the conductivity of polypyrrole (PPy), good biocompatibility of CS, and advantages of nanoparticles, CS-PPy nanocomposites were chosen and designed to modify the GCE for the retention of GODs biological activity and the vantage of electron transfer between GOD and electrodes. The GOD biosensor exhibited a fast amperometric response (5s) to glucose, a good linear current-time relation over a wide range of glucose concentrations from 5.00×10(-4) to 1.47×10(-1)M, and a low detection limit of 1.55×10(-5)M. The GOD biosensor modified with CS-PPy nanocomposites will have essential meaning and practical application in future that attributed to the simple method of fabrication and good performance.

Preparation, blood compatibility and anticoagulant effect of heparin-loaded polyurethane microspheres

Recent advances in micro- and nanotechnology have provided a variety of particles with highly controlled shapes, sizes, chemical composition, and interesting properties. In this work, a novel kind of heparin-functionalized polyurethane microsphere (Hep-PU MS) was synthesized by a single-step phase separation method. The blood compatibility and anticoagulant effect of the Hep-PU MSs were investigated using coagulation tests, hemolysis assay, complement and platelet activation detection, cytotoxicity analysis, and drug loading and release study. The results confirmed that the heparin can substantially enhance the anticoagulant properties of PU MSs, and the Hep-PU MSs have the potential to be used as a mild anticoagulant compared to heparin. With the simplicity of the functionalized method, the excellent hemocompatibility and the slow-release of heparin, the Hep-PU MSs with desirable bioproperties can be readily tailored to cater to various biomedical applications.

Preparation of water-soluble hyperbranched polyester nanoparticles with sulfonic acid functional groups and their micelles behavior, anticoagulant effect and cytotoxicity.

Biocompatibility of nanoparticles has been attracting great interest in the development of nanoscience and nanotechnology. Herein, the aliphatic water-soluble hyperbranched polyester nanoparticles with sulfonic acid functional groups (HBPE-SO3 NPs) were synthesized and characterized. They are amphiphilic polymeric nanoparticles with hydrophobic hyperbranched polyester (HBPE) core and hydrophilic sulfonic acid terminal groups. Based on our observations, we believe there are two forms of HBPE-SO3 NPs in water under different conditions: unimolecular micelles and large multimolecular micelles. The biocompatibility and anticoagulant effect of the HBPE-SO3 NPs were investigated using coagulation tests, hemolysis assay, morphological changes of red blood cells (RBCs), complement and platelet activation detection, and cytotoxicity (MTT). The results confirmed that the sulfonic acid terminal groups can substantially enhance the anticoagulant property of HBPE, and the HBPE-SO3 NPs have the potential to be used in nanomedicine due to their good bioproperties.

Hemocompatible and antibiofouling PU-F127 nanospheres platform for application to glucose detection in whole blood

Analysts are always enthusiastic about finding new materials with good biocompatibility to improve the behavior of biosensors. In this case, a novel electrochemical biosensor, which can be conveniently applied to veraciously evaluate the level of blood glucose with the help of antibiofouling technology, was prepared and investigated. More details of the preparation of polyurethane-Pluronic F127 (PU-F127) nanospheres and immobilizing glucose oxidase (GOx) on (PU-F127)-glass carbon electrode (GCE) were presented. The electrochemical behavior of the biosensor in whole blood was studied. The cyclic voltammetric results indicated that GOx immobilized on the PU-F127 nanospheres exhibited direct electron transfer reaction, which led to stable amperometric biosensing for glucose with a detection limit of 1.14 × 10-5 M (S/N = 3) in whole blood. The PU-F127 nanospheres modified GCE also offered good anti-interference ability to ascorbic acid (AA) and uric acid (UA), especially when a detection potential of -0.49 V was employed. The good stability and repeatability of this biosensor were also proved. The integration of the technologies, which include anticoagulants, sensors and nanoscience, will have significant input to high-performance biosensors relevant to diagnostics and therapies of interest for human health.

Fabrication of glucose biosensor for whole blood based on Au/hyperbranched polyester nanoparticles multilayers by antibiofouling and self-assembly technique.

Acknowledging the benefits of hyperbranched polymers and their nanoparticles, herein we report the design and synthesis of sulfonic acid group functionalized hydroxyl-terminated hyperbranched polyester (H30-SO3H) nanoparticles and their biomedical application. The H30-SO3H nanoparticles were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and proton nuclear magnetic resonance spectroscopy ((1)H NMR). The good hemocompatibility of H30-SO3H nanoparticles was also investigated by coagulation tests, complement activation and platelet activation. The novel glucose biosensor was fabricated by immobilizing the positively charged Au nanoparticles, H30-SO3H nanoparticles and glucose oxidase (GOx) onto the surface of glassy carbon electrode (GCE). It can be applied in whole blood directly, which was based on the good hemocompatibility and antibiofouling property of H30-SO3H nanoparticles. The biosensor had good electrocatalytic activity toward glucose with a wide linear range (0.2-20 mM), a low detection limit 1.2×10(-5) M in whole blood and good anti-interference property. The development of materials science will offer a novel platform for application to substance detection in whole blood.

Manganese Phosphate Self-assembled Nanoparticle Surface and Its application for Superoxide Anion Detection.

Quantitative analysis of superoxide anion (O2·−) has increasing importance considering its potential damages to organism. Herein, a novel Mn-superoxide dismutase (MnSOD) mimics, silica-manganous phosphate (SiO2-Mn3(PO4)2) nanoparticles, were designed and synthesized by surface self-assembly processes that occur on the surface of silica-phytic acid (SiO2-PA) nanoparticles. The composite nanoparticles were characterized by fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electronic microscopy (SEM), electron diffraction pattern, energy dispersive spectroscopy (EDS) and elemental mapping. Then the electrochemical measurements of O2·− based on the incorporation of SiO2-Mn3(PO4)2 onto the surface of electrodes were performed, and some satisfactory results were obtained. This is the first report that manganous phosphate (Mn3(PO4)2) nanoparticles with shape-controlled, but not multilayer sheets, were utilized for O2·− detection. The surface self-assembly technology we proposed will offer the ideal material to construct more types biosensor and catalytic system for its nanosized effect.