In this paper, size-controlled and surface-functionalized RhB-labeled and Cyclosporin A (CsA)-loaded polystyrene (PS) nanospheres were successfully synthesized via miniemulsion polymerization. The biophysical properties of PEG functionalized PS nanospheres from protein adsorption, blood compatibility, cell compatibility and cell penetrability showed the nanoparticles with high biocompatibility. These results indicated that PEG modified PS nanospheres showed outstanding properties as low size distribution (0.164), high encapsulation efficiency (98.3%), long re-calcification time (50% than positive control), low hemolysis ratio (3.19%) and high cell viability (95.3%). This work could be used as a good drug delivery system for CsA.

The amphiphilic and biocompatible behaviors of Poly (acetate-methylacrylic acid) Poly(EA-MAA) were investigated in this study. The aggregation behavior of Poly(EA-MAA) in aqueous media was investigated by steady-state fluorescence spectroscopy and surface tensiometry. The critical aggregation concentration (cac) of Poly(EA-MAA) was determined to be ∼0.03 mg/mL. Ultraviolet spectrum (UV) and fluorescence spectrum results indicated that there are interactions form between Poly(EA-MAA) and bovine serum albumin (BSA). And β-sheet can be changed into α-helix of BSA in Poly(EA-MAA) solution effectively revealed by Circular dichroism (CD), which is driven by the H-bond and hydrophobic interactions. The good cell-compatibility of Poly(EA-MAA) makes it great potential in the biomedical fields. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Poly (styrene-n-butyl acrylate-methyl methacrylate) (PSBM)/silica nanocomposite was prepared by emulsion polymerization in the presence of oleic acid surface modified nanosilica. The structure, morphology, size, and size distribution were characterized by Fourier transform infrared (FTIR), transmission electron microscopy (TEM), and dynamics laser scattering. The chemical bond was formed between PSBM and nanosilica revealed by FTIR and TEM studies. The composite particles with an averaged diameter ranging from 30 to 80 nm have the core-shell structure. The effect of silica content on the glass transition temperature T_g, pyrolyze temperature, and rheological behavior of PSBM composites was systematically investigated. The results indicated that the addition of nanosilica could effectively inhibit chain movement, and improved the pyrolyze temperature of PSBM. The steady viscosity and dynamic modulus were strongly dependent on the content and distribution of nanosilica in PSBM nanocomposites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

In this study, various polypropylene (PP) nanocomposites were prepared by melt blending method. The effects of different spherical nanofillers, such as 50 nm CaCO₃ and 20 nm SiO₂, on the linear viscoelastic property, crystallization behavior, morphology and mechanical property of the resulting PP nanocomposites were examined. Rheological study indicated that coincorporation of nano-SiO₂ and nano-CaCO₃ favored the uniform dispersion of nanoparticles in the PP matrix. Differential scanning calorimeter (DSC) and polarizing optical microscopy (POM) studies revealed that the coincorporation of SiO₂ and CaCO₃ nanoparticles could effectively improve PP crystallizability, which gave rise to a lower supercooling temperature (ΔT), a shorter crystallization half-life (t_1/2) and a smaller spherulite size in comparison with those nanocomposites incorporating only one type of CaCO₃ or SiO₂ nanoparticles. The mechanical analysis results also showed that addition of two types of nanoparticles into PP matrix gave rise to enhanced performance than the nanocomposites containing CaCO₃ or SiO₂ individually. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Hydrophobically modified nanosilica was prepared from tetraethoxysilane (TEOS) and γ-methacryloxypropyltrimethoxysilane (MPS) by a two step sol-gel process. The polystyrene-grafted-modified nanosilica (PS-g-mSiO₂) hybrid particles were prepared by grafting polystyrene onto the resulting hydrophobically modified nanosilica by dispersion polymerization. The hybrid nanoparticles were subsequently used as the filler to fabricate polypropyrene (PP) nanocomposites. The crystallization kinetics, crystal morphology and crystallization phase component of PS-g-mSiO₂/PP nanocomposite were studied using a differential scanning calorimeter (DSC), polarizing optical microscopy (POM) and X-ray diffraction (XRD). Crystallization half life (t_1/2) decreased, while the Arami exponent (n) of PS-g-mSiO₂/PP nanocomposite increased compared with that of virgin PP. A rheological study allowed the unambiguous characterization of the dispersibility of nanosilicas in PS-g-mSiO₂/PP nanocomposite. The storage modulus, melt viscosity and the elongation to break of the PS-g-mSiO₂/PP nanocomposite were found to be strongly dependent on the grafting of PS on nanosilicas. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers

Poly(lactic acid) (PLA)/SiO₂ nanocomposites were prepared via melt mixing with a Haake mixing method. To improve the dispersion of nanoparticles and endow compatibility between the polymer matrix and nanosilica, SiO₂ was surface-modified with oleic acid (OA). The interfacial adhesion of the PLA nanocomposites was characterized by field-emission scanning electron microscopy. The storage modulus and glass-transition temperature values of the prepared nanocomposites were measured by dynamic mechanical thermal analysis. The linear and nonlinear dynamic rheological properties of the PLA nanocomposites were measured with a parallel-plate rheometer. The effects of the filling content on the dispersability of the OA–SiO₂ nanoparticles in the PLA matrix, the interface adhesion, the thermomechanical properties, the rheological properties, and the mechanical properties were investigated. Moreover, the proper representation of the oscillatory viscometry results provided an alternative sensitive method to detect whether aggregation formed in the polymeric nanocomposites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Specifying the chemical environment of cells is a well-established method of controlling cellular behaviors. In this study, poly(ethylene terephthalate) (PET) film was selected as a typical biomaterial to detect the effects of chemical modifications on material surface in controlling cell behaviors. Natural biopolymer chitosan and its biocompatible derivative, O-carboxymethylchitosan (OCMCS) were surface immobilized on PET, respectively, via argon plasma followed by graft copolymerization with acrylic acid (AAc), which was exploited to covalently couple PET with chitosan (CS) and OCMCS molecules. Smooth muscle cells (SMCs) displayed a surface-dependent cell spreading and cytoskeletal organization. The cells spread with a more pronounced elongated spindle shape, smaller cell area, and lower cell shape index (CSI) on OCMCS-modified PET surface than on PET, or the PAA and chitosan-immobilized PET surfaces after 24 h of culture. Cell-culture viability after 5 days showed that all the modified materials possessed good cell proliferation. Our results suggest that cell adhesion, morphology, and growth can be mediated not only by varying the functional groups, electric charge, and wettability of PET surface but also by the specific biological recognition elicited from the biomaterials. These findings strongly support the concept that the microenvironment significantly influences cell behavior, highlighting the importance of environmental material biochemistry in cell-based tissue engineering schemes. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008

Poly(vinyl chloride) (PVC)/SiO₂ nanocomposites were prepared via melt mixture using a twin-screw mixing method. To improve the dispersion degree of the nanoparticles and endow the compatibility between polymeric matrix and nanosilica, SiO₂ surface was grafted with polymethyl methacrylate (PMMA). The interfacial adhesion was enhanced with filling the resulting PMMA-grafted-SiO₂ hybrid nanoparticles characterized by scanning electron microscopy. Both storage modulus and glass transition temperature of prepared nanocomposites measured by dynamic mechanical thermal analysis were increased compared with untreated nanosilica-treated PVC composite. A much more efficient transfer of stresses was permitted from the polymer matrix to the hybrid silica nanoparticles. The filling of the hybrid nanoparticles caused the improved mechanical properties (tensile strength, notched impact strength, and rigidity) when the filler content was not more than 3 wt %. Permeability rates of O₂ and H₂O through films of PMMA-grafted-SiO₂/PVC were also measured. Lower rates were observed when compared with that of neat PVC. This was attributed to the more tortuous path which must be covered by the gas molecules, since SiO₂ nanoparticles are considered impenetrable by gas molecules. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

We prepared a novel copolymeric latex of vinyl acetate and n-butyl acrylate (V-B) using a semibatch emulsion polymerization process. The glass-transition temperature (T_g), steady viscosity, flow activation energy (E_f), dynamic moduli, and amphiphilic properties of the V-B latex in the presence of colophony were systematically investigated. The experimental results demonstrate that excellent adhesive behaviors were achieved for the V-B latex blended with 20 wt % colophony, whereas good adhesive performance was related to the moderate T_g, viscosity, E_f, storage modulus, and low contact angle on the adherent. The debonding mechanisms for V-B and its colophony-modified latexes were analyzed. A possible mechanism for the V-B latex blended with colophony emulsion was determined. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Biocompatible and polymerizable natural macromolecules have been found to provide great advantages in the preparation of hydrogels, which have wide applications in the fields of tissue engineering and polymeric drug delivery systems. To develop a new biocompatible polymerizable chitosan derivative, N-maleic acyl-chitosan (NMCS) was synthesized in this study. This novel biomaterial was designed from the N-acylation of chitosan with maleic anhydride introducing functional carboxyl and vinylated (CC) groups. The structure of NMCS was characterized by FTIR, ¹H NMR, element analysis, and X-ray diffraction (XRD). NMCS can be dissolved into water because of its decreased crystallinity compared with chitosan. The NMCS's multiporous and microgel morphology was revealed by transmission electron microscope (TEM). Crosslinked hydrogel films can be successfully obtain through the macromolecular polymerization of NMCS. Subsequently, 3T3 fibroblasts were cultured onto the surface of the polymerized NMCS (P-NMCS) films to examine the capability of cell attachment and proliferation. Results from the cell culture demonstrate that P-NMCS films provide significant improvement in cell attachment and proliferation over unmodified chitosan. The improved P-NMCS cytocompatibility is expected to provide substantial contributions to tissue engineering in the future. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008