Preparation and characterization of hydroxycamptothecin-loaded Poly(D,L-lactic acid) nanoparticles with high drug loading capacity

Conference Name:2nd International Conference on Material Engineering, Chemistry, Bioinformatics (MECB 2012). Conference Address: Xian, PEOPLES R CHINA. Time:JUL 14-15, 2012.Hydroxycamptothecin (HCPT) loaded PLA nanoparticles were prepared by a facile dialysis method. Three main influential factors, PLA concentration, ratio of HCPT to PLA (wt/wt), dialysis bags with different molecule weight cutoff, were evaluated using an orthogonal design, gave the nanoparticles with an average diameter of approximately 226.8 nm and fine drug loading content (5.16%, w/w). The in vitro drug release studies exhibited a slow and prolonged release profile over 30 days. It is concluded that the new method to prepare HCPT-PLA nanoparticles resulted in improved formulation characteristics including small size, high drug loading capacity, and long sustained drug release

Phytosomes Loaded with Mitomycin C-Soybean Phosphatidylcholine Complex Developed for Drug Delivery

A novel formulation system of phytosomes loaded with mitomycin C soybean phosphatidylcholine (MMC-SPC) complex (MMC-loaded phytosomes) was prepared by a solvent evaporation method combined with a nanoprecipitation technique for the purpose of development of an MMC drug delivery system. The MMC-loaded phytosomes were evaluated by average particle size, zeta-potential, and residual drug-loading content as well as an in vitro drug release profile. Furthermore, in vitro stability tests and in vitro/vivo biological evaluations of the MMC-loaded phytosomes were performed. DSC, FTIR, and XRD demonstrated that MMC interacted physically with SPC within the phytosomes. DLS and ELS described a dispersion with an average particle size of 210.87 nm, a narrow size distribution (PDI 0.251), and a zeta-potential of -33.38 mV. SEM, TEM, and AFM images showed that the MMC-loaded phytosomes were spherical and intact vesicles. In vitro stability tests demonstrated that the average particle size and residual drug-loading content of the MMC-loaded phytosomes had no evident change at different storage conditions. In vitro drug release profiles indicated biphasic behavior with an initial burst release, followed by a subsequent prolonged sustained release. In vitro cytotoxicity assays with H-22 cells showed that the MMC-loaded phytosomes had remarkable cytotoxicity. In vivo antitumor effect of the MMC-loaded phytosomes also revealed a dose-dependent and superior curative inhibitory effect on tumor growth without loss of body weight compared to free MMC. Histopathological analysis of specimens taken from tumor tissues indicated that MMC-loaded phytosomes had lethal effect to hepatoma cell. These findings suggested that the MMC-loaded phytosomes can serve as a promising and effective formulation for drug delivery and cancer therapy

Synthesis of dumbbell-like ZnO microcrystals via a simple solution route

National Natural Science Foundation of China [81000660]; National Nature Science Foundation of China [90923042]; Xiamen Science and Technology project [3502Z20123001]Uniform dumbbell-like ZnO microcrystals had been successfully fabricated on a large scale via a facile solution technique under mild conditions. Obtained ZnO, with length of 1.2 to 1.6 mu m and diameters of 350 to 600 nm, exhibited well-defined dumbbell-like morphology and hexagonal wurtzite structure and grew along the [001] direction. Effects of the reactant concentration on the sizes and morphologies of the ZnO products had been investigated, indicating that the reactant concentration played a crucial role in determining final sizes and shapes of the samples. In addition, the growth process of the dumbbell-like ZnO microcrystals was studied, and a possible formation mechanism was proposed. Furthermore, the optical properties of ZnO samples obtained at various reaction times were also investigated by photoluminescence (PL) spectroscopy. The PL spectra of the as-prepared dumbbell-like ZnO microcrystals showed a strong UV emission peak

Development of multifunctional folate-poly(ethylene glycol)-chitosan-coated Fe3O4 nanoparticles for biomedical applications

The efficacy of magnetic nanoparticles (MNPs) for biomedical applications depends on the specic targeting capacity, blood circulation time and magnetic susceptibility. Functionalized chitosan-coated Fe3O4 nanoparticles (CS-coated Fe3O4 NPs) were synthesized by a non-solvent-aided coacervation procedure followed by a chemical crosslinking procedure. The surfaces of CS-coated Fe3O4 NPs were successfully functionalized with folate-poly(ethylene glycol)-COOH (FA-PEG) to obtain novel FA-PEG-CS-coated Fe3O4 NPs endowed with long blood circulation and specic targeting capacity. The as-synthesized NPs were characterized by dynamic light scattering, transmission electron microscope, X-ray diffraction, thermal gravimetric analysis, vibration sample magnetometer, Fourier transform infrared spectroscopy, and confocal laser scanning microscopy. As a result, the novel FA-PEG-CS-coated Fe3O4 NPs showed excellent biocompatibility, magnetic properties, good dispersibility, and proper hydrodynamic sizes in an aqueous medium. The specific targeting capacity of the as-synthesized NPs to cancer cells was also investigated. It was observed that the uptake of the FA-PEG-CS-coated Fe3O4 NPs by HeLa cells was significantly enhanced compared to the CS-coated Fe3O 4 NPs and mPEG-CS-coated Fe3O4 NPs. These results clearly indicate that our novel FA-PEG-CS-coated Fe3O 4 NPs with remarkable specific targeting capacity, long blood circulation, and superparamagnetism hold great promise for biomedical applications, including targeted drug delivery and hyperthermia therapy. [Figure not available: see fulltext.] ? 2014 The Polymer Society of Korea and Springer Sciene+Business Media Dordrecht

A comparative in vitro evaluation of self-assembled PTX-PLA and PTX-MPEG-PLA nanoparticles

National Natural Science Foundation of China [81000660, 31271071]; Xiamen Science and Technology Project [3502Z20123001, 3502Z20114007]We present a dialysis technique to direct the self-assembly of paclitaxel (PTX)-loaded nanoparticles (NPs) using methoxypolyethylene glycol-poly(d,l-lactide) (MPEG-PLA) and PLA, respectively. The composition, morphology, particle size and zeta potential, drug loading content, and drug encapsulation efficiency of both PTX-PLA NPs and PTX-MPEG-PLA NPs were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, dynamic light scattering, electrophoretic light scattering, and high-performance liquid chromatography. The passive targeting effect and in vitro cell viability of the PTX-MPEG-PLA NPs on HeLa cells were demonstrated by comparative cellular uptake and MTT assay of the PTX-PLA NPs. The results showed that the PTX-MPEG-PLA NPs and PTX-PLA NPs presented a hydrodynamic particle size of 179.5 and 441.9 nm, with a polydispersity index of 0.172 and 0.189, a zeta potential of -24.3 and -42.0 mV, drug encapsulation efficiency of 18.3% and 20.0%, and drug-loaded content of 1.83% and 2.00%, respectively. The PTX-MPEG-PLA NPs presented faster release rate with minor initial burst compared to the PTX-PLA NPs. The PTX-MPEG-PLA NPs presented superior cell cytotoxicity and excellent cellular uptake compared to the PTX-PLA NPs. These results suggested that the PTX-MPEG-PLA NPs presented more desirable characteristics for sustained drug delivery compared to PTX-PLA NPs