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To prepare RGD peptide modified perfluorohexane ( PFH ) polymer nanoparticles RGD‐PFH‐NPs and investigate its basic characteristics ,targeting ability and combine with low‐intensity focused ultrasound ( LIFU ) for ultrasonic imaging in vivo and vitro . Methods Targeted nanoparticles RGD‐PFH‐NPs were prepared by double emulsifying method and carbodiimide method . T heir morphology and distribution were observed . T he particle size ,zeta potential and connection probability were measured . T he phase‐changed properties and the LIFU‐induced imaging ability in contrast‐enhanced ultrasound mode of RGD‐PFH‐NPs were investigated in vivo and vitro . T he tagetability of nanoparticles to human gastric cancer cell line M GC803 and tumor‐bearing nude mouse were observed through targeting group and non‐targeting group . Results T he prepared sample was milky w hite suspension liquid . T he RGD‐PFH‐NPs were spherical uniform size ,good dispersion w hen observed through the optical microscope and transmission electron microscopy . T he particle size was ( 259 .3 ± 42 .6) nm and the Zeta potential was ( －17 .6+5 .4) mV . T he connection probability of RGD peptide was 89 .13% . With 70℃ water bath and LIFU stimulation RGD‐PFH‐NPs can remarkably change phase and show good imaging performance in both conventional ultrasound and contrast‐enhanced ultrasound mode in vivo and vitro . The connection probability to M GC803 cells in targeting group ( RGD‐PFH‐NPs ) and the non‐targeting group( PFH‐NPs) were 82 .59% and 2 .96% . T he accumulation of nanoparticles in the RGD‐PFH‐NPs group in tumor tissues was significantly higher than that in the non‐targeted PFH‐NPs group( P) . Conclusions The constructed nanoparticles RGD‐PFH‐NPs ,providing contrast‐enhanced ultrasonic imaging and excellent targeting ability to human gastric cancer cells M GC803 and gastric cancer tissue ,is expected to become a new type of gastric cancer targeted ultrasound contrast agent .
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This work reports on the synthesis, with the thermally induced phase separation (TIPS) technique, of poly (l-lactide) (PLLA) scaffolds containing Fe-doped hydroxyapatite (FeHA) particles for bone regeneration. Magnetization curves and X-ray diffraction indicate two magnetic particle phases: FeHA and magnetite Fe3O4. Magnetic nanoparticles (MNPs) are approximately 30 ± 5 nm in width and 125 ± 25 nm in length, and show typical ferromagnetic properties, including coercivity and rapid saturation magnetization. Scanning electron microscopy (SEM) images of the magnetic scaffolds reveal their complex morphology changes with MNP concentration. Similarly, at compositions of approximately 20% MNPs, the phase separation changes, passing from solidâ»liquid to liquidâ»liquid as revealed by the hill-like structures, with low peaks that give the walls in the SEM images a surface pattern of micro-ruggedness typical of nucleation mechanisms and growth. In vitro degradation experiments, carried out for more than 28 weeks, demonstrated that the MNPs delay the scaffold degradation process. Cytotoxicity is appreciated for FeHA content above 20%.
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The N1,N1'-(ethane-1,2-diyl)bis(N2-phenyloxalamide) (OXA) is a soluble-type nucleator with a dissolving temperature of 230 °C in poly(l-lactic acid) (PLLA) matrix. The effect of thermal history and shear flow on the crystallization behavior of the PLLA/OXA samples was investigated by rheometry, polarized optical microscopy (POM), differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), and scanning electron microscopy (SEM). The crystallization process of the PLLA/OXA-240 sample (i.e., pre-melted at 240 °C) was significantly promoted by applying a shear flow, e.g., the onset crystallization time (tonset) of the PLLA at 155 °C was reduced from 1600 to 200 s after shearing at 0.4 rad/s for even as short as 1.0 s, while the crystallinity (Xc) was increased to 40%. Moreover, the tonset of the PLLA/OXA-240 sample is 60%â»80% lower than that of the PLLA/OXA-200 sample (i.e., pre-melted at 200 °C) with a total shear angle of 2 rad, indicating a much higher crystallization rate of the PLLA/OXA-240 sample. A better organization and uniformity of OXA fibrils can be obtained due to a complete pre-dissolution in the PLLA matrix followed by shear and oscillation treatments. The well dispersed OXA fibrils and flow-induced chain orientation are mainly responsible for the fast crystallization of the PLLA/OXA-240 samples. In addition, the shear flow created some disordered α'-form crystals in the PLLA/OXA samples regardless of the thermal history (200 or 240 °C).
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The fourth generation poly( amidoamine) dendrimers ( G4. 0 PAMAM) functionalized multiwalled carbon nanotube ( G4 . 0-MWCNTs ) was prepared by amidation between carboxylated multiwalled carbon nanotube (MWCNTs) and G4. 0 PAMAM. Then a novel hydrogen peroxide (H2O2) sensor was fabricated by electrodepositing Pd nanoparticles (NPs) on a glassy carbon electrode (GCE) modified with G4. 0-MWCNTs composites. The modified electrode was characterized by field emission scanning electron microscopy ( FESEM) , cyclic voltammetry ( CV) and electrochemical impedance spectroscopy ( EIS) . A large amounts of highly dispersion PdNPs could be well loaded on the surface of the G4. 0-MWCNTs, and the modified electrode exhibited excellent electrocatalytic activity towards the reduction of H2 O2 . Under the optimized conditions, the reduction peak currents of H2 O2 were linear to their concentrations in the range from 1. 0 × 10-9 mol/L to 1. 0×10-3 mol/L and the limit of detection of 2. 3×10-8 mol/L was obtained. The recovery of standard addition for human serum samples was 96 . 7%-103 . 1%.
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Poly ( duenedumethylammonuum chlorude ) ( PDDA ) functuonaluzed sulver nanopartucles ( AgNPs ) prepared wuth PDDA as the protectuve and reductuve agents was combuned wuth graphene oxude ( GO ) to prepare PDDA functuonaluzed cubuc sulver nanopartucles ( C-AgNPs)/GO composute, whuch was then modufued on a glassy carbon electrode ( GCE) to form C-AgNPs-PDDA/GO/GCE. The surface morphologues of dufferent modufued electrodes were characteruzed by scannung electron mucroscope ( SEM ) , and theur correspondung cycluc voltammetruc ( CV) behavuors were unvestugated, unducatung that the composute of C-AgNPs-PDDA/GO exhubuted excellent electrocatalytuc oxudatuon actuvuty to DA and NO-2 . By usung dufferentual pulse voltammetry, the responses of C-AgNPs-PDDA/GO/GCE were lunear un the ranges of 0 . 030-0 . 300 μmol/L and 0 . 300-300 μmol/L wuth detectuon lumut of 9. 8 nmol/L (S/N=3) for DA, and 30. 0-2300 μmol/L wuth detectuon lumut of 12. 6 μmol/L (S/N=3) for NO-2, respectuvely. The modufued electrode dusplayed good selectuvuty, reproducubuluty and stabuluty, and could be used for the sumultaneous determunatuon of DA and NO-2 un human serum samples wuth recoverues of 97. 4%-104. 2% and 98. 0%-102. 8%, respectuvely. Compared wuth spectrophotometruc method, the determunatuon results were satusfactory, showung that the modufued electrode possessed a potentual applucatuon value.
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Poly ( aniline_luminol ) composite nanowires were synthesized by chemical oxidation using ammonium peroxydisulfate. In contrast to the maximum fluorescence emitting wavelength of luminol at 425 nm, the maximum fluorescence emitting wavelength of the polymeric luminol in the composite nanowires was red shifted to 465 nm obviously. The poly ( aniline_luminol) composite nanowires were modified on graphite electrode surface by drop coating, forming a stable poly ( aniline_luminol ) composite nanowires film. The composite nanowires film modified electrode presented favorable electrochemiluminescence ( ECL ) performances, and the ECL response could be enhanced by hydrogen peroxide. Under the optimized experimental conditions, the modified electrode provided a linear range of 5. 0×10-9-1. 0×10-5 mol/L for the detection of hydrogen peroxide with a detection limit of 2 ×10-9 mol/L.
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Abstract?AlM: To investigate the effect of zebularine ( Zeb ) loaded Poly ( ethylene glycol ) - block - poly ( ε -caprolactone) methyl ether ( MePEG-PCL) nanoparticles ( NPs) on the viability, attachment, and apoptosis of in vitro cultured lens epithelial cells ( LECs) .?METHODS: In vitro cultured infant human lens tissue HLE B-3 immortalized cells were distributed randomly divided into six groups. Each group was administered with free Zeb 50μmol/L ( ZebF1 group ) , 100μmol/L ( ZebF2 group) , Zeb -loaded MePEG-PCL NPs 50μmol/L ( ZebNP1 group) , Zeb -loaded MePEG-PCL NPs 100μmol/L ( ZebNP2 group) , MePEG-PCL empty NPs( NPs group) or blank medium (group C) respectively. A tetrazolium dye assay ( MTT) test and modified MTT test were performed to determine cell viability and cell attachment. DNA ladder was used to detect the cell apoptosis.?RESULTS: Determined by MTT colorimetric method:Cell proliferation rate of LECs were suppressed by all Zeb administration groups in a concentration-time dependent manner (P ZebNP1>ZebF2 (P<0. 05).?CONCLUSlON: Zeb loaded MePEG-PCL NPs had better effect on suppressing the viability and attachment of in vitro cultured LECs than the free Zeb groups , as well as enhancing the apoptosis.
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A poly( GMA-EGDMA) coated SPME fiber was prepared using an in-situ polymerization by direct bonding to the surface of a polydopamine-modified stainless steel wire. Then the fiber was modified by sulfuric acid. A novel solid phase microextraction coating coupled to high performance liquid chromatography ( HPLC) method based on the as-prepared fiber was developed for the determination of four pharmaceuticals and personal care products ( PPCPs) in water samples. The influences of extraction parameters, including pH, extraction time, extraction temperature and salt addition were investigated. 3 mL water sample was extracted by the as-prepared fiber for 60 min at 30 ℃, and then desorbed with mobile phase for 30 min, respectively. Desorption solution was analyzed by HPLC-DAD ( diode array detection ) . The results indicated that the extraction yield of the fiber was good for four PPCPs. The linear correlation coefficients were>0. 997 with the linear range of 2-200 μg/L. The limits of detection (S/N=3) were 0. 5-5 μg/L with RSD (n=5) of 4. 1%-11. 9%. The recoveries of four PPCPs at spiked level of 20, 50, 100 μg/L were within the range of 70. 6%-105. 5%. The results showed that this method was easy, green, accurate and precise, and could be used to assay the four PPCPs in real water samples.
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Background The tissue-engineered cornea is becoming the hot spot in the ophthalmologic field,while the research of corneal substitute is in the ascendant,because it is more similar to the corneal morpha and easy to survive in vivo.Objective This study was to investigate the biocompatibility of recombinant human type-Ⅲ collagen/poly9 ( 3-( methacryloylamino ) propyl dimethyl ( 3-sulfopropyl ) ammonium hydroxide ) ( PMPDSAH ) interpenetrating polymer network (IPN) (RHC-Ⅲ/PMPDSAH IPN) hydrogel as a tissue-engineered cornea in rabbit eye and its feasibility as the corneal substitute.Methods One hundred and eight rabbits were randomly divided into experimental group( 90 rabbits) and normal control group ( 3 rabbits),and 15 rabbits ( 30 eyes ) used as the donor corneas.RHC-Ⅲ/PMPDSAH IPN,NGF PMPDSAH IPN and corneal grafts were lamellarly transplanted into the right eyes in RHC-Ⅲ/PMPDSAH IPN group,NGF PMPDSAH IPN group and allograft group respectively.The corneal transparency and neovascularization were examined and scored under the slim lamp and compared among three groups using Kraskal-Wallis H test.The corneal epithelization time was observed and compared among these three groups using one way analysis of variance and LSD-t test.The histological examination of corneas was performed at the 3rd day,1st and 2nd week,1 st,3rd and 6th month after the surgery.The immunohistochemistry was used to detect the expression of K3 in cornea at the 6th month.Results The grafts were well attached in RHC-Ⅲ/PMPDSAH IPN group,NGF PMPDSAH IPN group and allograft group,and no rejection reaction was found throughout 6-month following up.Compared with normal control group,no significant differences were found in the scores of corneal opacification and neovescularization in these three groups (x2 =4.34,P =0.23 ;x2 =2.60,P =0.46 ) at the 6th month.NGF PMPDSAH IPN group achieved reepithelialization in (4.97±0.63) days and was obviously shorted than that in RHC-Ⅲ/PMPDSAH IPN group and allograft group ( t =11.97,P =0.00; t =5.80,P =0.00).The re-epithelialization time in RHC-Ⅲ/PMPDSAH IPN was (6.86±0.71) days,and that of allograft group was (5.87±0.43 ) days,showing a significant difference ( t =6.32,P =0.00).Hematoxylin-eosin staining results demonstrated that implanted materials integrated into the host corneal tissue well and support corneal epithelialization.Part of the material degraded at the 2nd week and degraded completely 1 month later.Regular alignment and distribution of collagen fibers were seen in the regenerated cornea and were similar to those of the normal stroma in 6 months.Immunohistochemistry showed the positive expression of keratin-3 in corneal epithelial cells.Conclusions RHC-Ⅲ/PMPDSAH IPN has a good biocompatibility without toxicity to corneal tissue.Furthermore,NGF can promote the corneal wound-healing and re-epithelialization.The material can be used as safe and reliable corneal substitute after improving the mechanical strength.
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In recent years, tumor is a refractory disease occurring frequently which is the main cause of death. Surgery, radiotherapy and chemotherapy are the usual therapeutic tools. However,radiotherapy and chemotherapy have serious side-effects and surgery can not be used effectively when metastasis happened. Therefore, tumor-targeted therapy has developed as a better way to cure tumor. Development of research on the use of PEG-PLGA nanoparticles as drug carriers are reviewed in this article, furthermore, problems about that are analysed.