三羟甲基丙烷三丙烯酸酯-苯乙烯沉淀聚合高产率制备高交联单分散聚合物微球

以三羟甲基丙烷三丙烯酸酯(TMPTA)-苯乙烯(St)为单体,偶氮二异丁腈(AIBN)为自由基引发剂,通过在乙醇中的沉淀聚合可制得高交联单分散P(TMPTA-St)聚合物微球.对单体转化率,微球以及可溶性低聚物的产率进行了测试.结果表明,使用10 wt%至60 wt%的交联剂TMPTA进行聚合可获得单分散微球,产率在50%左右.增加TMPTA用量可提高微球产率和单体转化率.增加引发剂AIBN用量对提高微球产率也有促进作用,但同时可溶性低聚物产率也增加.向乙醇中加入水作为反应介质结合适当增加AIBN用量可使单体转化率达到98%,微球产率高于90%.对实验结果进行了解释,对聚合机理进行了讨论.     

Crystal growth,spectral characterization and structural studies of a luminescent coordination polymer of calcium(II) complex of benzilic acid

Single crystals of a new calcium(II) complex of benzilic acid, [Ca(C₁₄H₁₁O₃)₂(C₁₄H₁₂O₃)₂] have been successfully grown by gel diffusion technique at room temperature. Single crystal X-ray diffraction study reveals that the compound belongs to orthorhombic system with space group Fddd. The adjacent CaO₈ units are linked via O–H–O interaction to form one dimensional polymeric chains. The extensive hydrogen bonding interactions lead to a supramolecular structure. The grown crystals were further characterized by elemental analysis, FT-IR, UV–Visible, thermogravimetric, powder X-ray diffraction and solid state photoluminescence studies.     

Fungal keratitis infected eye treatment with antibiotic-loaded zinc ions tagged polyvinyl acetate phthalate-g-polypyrrole drug carrier

Currently, the treatment of fungal keratitis (FK) infection remains a major clinical challenge, and current investigations, development in the field have widened approaches. The present work was aimed to synthesis a dual role novel carrier system consisting of Ofloxacin (OFL) and Nepafenac (NF) hydrophobic drugs incorporated in Zinc ions (Zn²⁺) tagged Polyvinyl acetate phthalate (PVAP) grafted Polypyrrole (PPy) carrier (OFL&NF-Zn²⁺/PVAP-g-PPy) to treat FK infection. The FT-IR, SEM, and dynamic light scattering revealed the carrier chemical structure, spherical shape, and the average particle size of 691.3 ± 1 nm. The carrier’s entrapment of OFL and NF drugs has been observed at 78.23% and 60.03%. The carrier exhibited significant antifungal activity at the concentration of 58 mg mL⁻¹ against Candida albicans which was lower than that of the free ofloxacin. The cell viability results suggested up to 70 μg/mL concentration of OFL&NF-Zn²⁺/PVAP-g-PPy did not induce any cytotoxicity on cultured ADSC cells at 48 h treatment time. It confirms the fact that the OFL&NF-Zn²⁺/PVAP-g-PPy carrier showed good biocompatibility and good anti-fungal activity. Thus the carriers provide a significant potential to improve the bioavailability of topically applied drugs to treat fungal eye infection.     

LHRH/TAT dual peptides-conjugated polymeric vesicles for PTT enhanced chemotherapy to overcome hepatocellular carcinoma

Combination therapy such as photothermal therapy (PTT) enhanced chemotherapy is regarded as a promising strategy for cancer treatment. Herein, we developed redox-responsive polymeric vesicles based on the amphiphilic triblock copolymer PCL-ss-PEG-ss-PCL. To avoid the limited therapeutic effect of chemotherapeutic drugs caused by systemic exposures and drug resistance, the redox-sensitive polymeric vesicles were cargoed with two chemotherapeutics: doxorubicin (DOX) and paclitaxel (PTX). Besides, indocyanine green (ICG) was encapsulated, and cell-penetrating peptides and LHRH targeting molecule were modified on the surface of polymeric vesicles. The results indicated that the polymeric vesicles can load different kinds of drugs with high drug loading content, trigger drug release in responsive to the reductive environment, realize high cellular uptake via dual peptides and laser irradiation, and achieve higher cytotoxicity via chemo-photothermal combination therapy. Hence, the redox-responsive LHRH/TAT dual peptides-conjugated PTX/DOX/ICG co-loaded polymeric micelles exhibited great potential in tumor-targeting and chemo-photothermal therapy.     

Preparation and adsorption property of novel inverse-opal hierarchical porous N-doped carbon microspheres

The design of pore structure is the key factor for the performance of porous carbon spheres.In this wo rk,novel micron-sized colloidal crystal microspheres consisting of fibrous silica(F-SiO_2) nanoparticles are firstly prepared by water-evapo ration-induced self-assembly of F-SiO_2 nanoparticles in the droplets of an inverse emulsion system to be used as sacrificial templates.Acrylonitrile(AN) was infiltrated in the voids of the F-SiO_2 colloidal crystal microspheres,and in-situ induced by ~(60)Co y-ray to polymerize into polyacrylonitrile(PAN).After the PAN-infiltrated F-SiO_2 colloidal crystal microspheres were carbonized and etched with HF solution,novel micron-sized inverse-opal N-doped carbon(IO-NC) microspheres consisting of hollow carbon nanoparticles with a hierarchical macro/meso-porous inner surface were obtained.The IO-NC microspheres have a specific surface area as high as 266.4 m~2/g and a molar ratio of C/N of 5.They have a good dispersibility in water,and show a high adsorption capacity towards rhodamine B(RhB) up to 137.28 mg/(g microsphe re).This work offers a way to obtain novel micron-sized hierarchical macro/meso-porous N-doped carbon microspheres,which opens a new idea to prepare high-performance hierarchical porous carbon materials.     

Preparation and Characterization of Vanillin Cross-Linked Chitosan Microspheres of Pterostilbene

A vanillin cross-linked chitosan microsphere delivery system was established for stabilization and controlled release of pterostilbene. The prepared microspheres were characterized by SEM images, FT-IR spectra, thermogravimetry, and X-ray diffraction. FT-IR spectra results indicated that chitosan was cross-linked by vanillin successfully. Thermal analysis showed that pterostilbene had been totally incorporated into the microspheres and the encapsulation of pterostilbene decreases the rate of degradation and increases the stability. XRD analysis was conducted to confirm the results of DSC analysis. The release rate of pterostilbene from microspheres in pH 3.6 buffer solution could be up to 58.1 % within 48 h.     

A New Cells‐Compatible Microfluidic Device for Single Channel Recordings

We report the fabrication of a microfluidic apparatus and the realization of a sensors based on PEDOT : PSS, a biocompatible semiconductor polymer used in substitution of standard electrodes for electrophysiological studies and for detection of nanopores in membrane. This gives the possibility to study the mechanisms of ions balance and molecular transport though cell membranes. In particular the apparatus is based on two chambers connected through an aperture in a PTFE sheet where lipid bilayer are formed using Montal‐Mueller method, and the pore‐forming proteins activity is detected by polymeric electrodes. This methodology could be applied to examine different membrane proteins for the purpose of biosensing, drug screening and nanopore technologies.     

Preparation of P(MBA‐co‐MAA)/Zr(OH)4/P(EGDMA‐co‐MAA)/TiO2 Tetra‐layer Hybrid Microspheres and the Corresponding ZrO2/TiO2 Double‐shelled Hollow Microspheres

Double‐shelled zirconia/titania (ZrO₂/TiO₂) hollow microspheres were prepared by the selective removal of the polymer components via the calcination of the corresponding tetra‐layer poly(N,N′‐methylenebisacryl amide‐co‐methacrylic acid) (P(MBA‐co‐MAA))/Zr(OH)₄/poly(ethyleneglycol dimethacrylate‐co‐methacrylic acid) (P(EGDMA‐co‐MAA))/TiO₂ hybrid microspheres. These tetra‐layer microspheres were synthesized by the combination of the distillation copolymerization of N,N(‐methylenebisacryl amide‐co‐methacrylic acid (MBA) or ethyleneglycol dimethacrylate (EGDMA) crosslinker and methacrylic acid (MAA) for the preparation of polymer core and third‐layer as well as the controlled sol‐gel hydrolysis of inorganic precursors for the construction of zirconium hydroxide (Zr(OH)₄) and titania (TiO₂) layers. The thicknesses of zirconia and titania shell‐layers were conveniently controlled via varying the feed of zirconium n‐butoxide (Zr(OBu)₄) and titanium tetrabutoxide (TBOT) during the sol‐gel hydrolysis, while the sizes of polymer layers were tuned through a multi‐stage distillation precipitation copolymerization. The structure and morphology of the resultant microspheres were characterized by transmission electron microscopy (TEM), X‐ray diffractometer (XRD), X‐ray photoelectronic spectroscopy (XPS), and thermogrametric analysis (TGA).     

3-氨基丙醇调控合成超顺磁四氧化三铁微球

采用乙二醇为溶剂,无水FeCl3为铁源,聚丙烯酸为稳定剂,通过改变3-氨基丙醇的用量,合成了一系列不同微球直径和晶粒大小的超顺磁Fe3O4微球。高分辨率透射电镜和X-射线衍射分析证实所得产物为Fe3O4,红外光谱和热重分析表明,微球表面成功包覆聚丙烯酸。微球的大小和组成微球的颗粒粒径分别用透射电镜和X-射线衍射分析,结果表明,所得微球的直径随着3-氨基丙醇的用量增加而减小,组成微球的颗粒粒径随着3-氨基丙醇的用量增加而增大。磁性测试表明所制备微球室温下具有良好的超顺磁性。该制备方法步骤简单,可望用于其他无机氧化物纳米微球或颗粒的制备。