The complexes of adenovirus and anionic liposomes: preparation and in vitro characterization / 药学学报

This study is to report the preparation of complexes of Ad5 and anionic liposomes (AL-Ad5), the amplification of adenoviruses with enhanced green fluorescent protein (eGFP) reporter gene performed by HEK 293 cells, the adenoviral vectors purified by cesium chloride gradient centrifugation, and the titer of adenovirus determined by cytopathic effect (CPE) method, hexon capsid immunoassay and quantitative-PCR (Q-PCR), separately. The prescription and experiment conditions were optimized by central composite design (CCD). The complexes of Ad5 and AL-Ad5 were formulated by the calcium-induced phase change method. The morpholopy, particle size and zeta potential were detected by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. Additionally, the bicolourable fluoresce-labeled complexes (F(labeled)-AL-Ad5) were prepared and their intracellular location in MDCK cells was detected by confocal laser scanning microscopy (CLSM). The results indicate that the complexes of AL-Ad5 exhibited a uniform distribution with a particle size of 211 +/- 10 nm and a zeta potential of -41.2 +/- 2.2 mV. The result of CLSM demonstrates that the intracellular location of red fluoresce-labeled adenovirus was consistent with that of green fluoresce-labeled liposomes suggesting that the naked adenovirus was well encapsulated by the anionic liposomes in complexes of AL-Ad5.

Quantitative determination of adenovirus and carmustine in anionic liposomes-mediated co-delivery system / 中国药学杂志

OBJECTIVE: To establish effective and reliable methods for the determination of adenovirus and carmustine in anionic liposomes-mediated co-delivery system. METHODS: The complexes of co-delivery system were prepared by calcium-induced phase changing method. For carrying out the quantitative-PCR (Q-PCR) detection, the sequences of primer and probe were designed accoding to the hexon gene sequences of Ad5, and then the reaction system of Q-PCR was optimized to detect the loading rate of Ad5. The HPLC condition was also optimized to determine the drug loading of carmustine in the co-delivery system. RESULTS: In the co-delivery system, the loading rate of adenovirus detected by Q-PCR method was (23.2±1.8)% and that of carmustine was (55±2.8)%. CONCLUSION Both of Q-PCR and HPLC methods have been successfully used for the quantification of adenovirus and carmustine in anionic liposomes-mediated co-delivery system. These methods are simple, reliable and accurate, which can be used in other similar experiments.

Preparation and gene expression of transferrin modified gene loaded procationic liposomes / 药学学报

A novel transferrin modified non-viral gene delivery system Tf-PLPD was developed and the related characteristics was investigated. Blank procationic liposomes were prepared by film dispersion-filteration method. PLPD was prepared as follows by first mixing the plasmid DNA and protamine together, then the resulted polyplexes were incubated for 10 min at room temperature, followed by addition of preformed blank procationic liposomes. Transferrin was adsorbed at the surface of PLPD via electrostatic interactions to form Tf-PLPD. Central composite design (CCD) was employed to optimize the formulation. The HepG2 cells were transfected using lacZ as reporter gene and characteristics such as the morphology, the mean particle size, the zeta potential and the transfection efficiency in HepG2 cells were further investigated by different methods. The resulting PLPD had a regular spherical surface with an average size of (228. 9 +/- 8. 0) nm (polydispersity index, PDI = 0. 122 +/- 0. 02, n = 3) , a zeta potential of ( - 25. 08 +/-2. 50) mV (n = 3) and a transfection efficiency of (12. 18 +/- 3. 80) mU x mg(-1) (protein). The Tf-PLPD had an average size of (240 +/- 12) nm (polydispersity index, PDI = 0. 150 +/- 0. 03, n = 3), a zeta potential of ( - 24. 10 +/- 2. 50) mV ( n = 3) and a transfection efficiency of (24. 26 +/- 2. 60) mU x mg(-1) (protein) , 20 times greater than that of the naked plasmid DNA. The presence of serum didn' t affect the tansfection activity of PLPD or Tf-PLPD. Compared to one kind of cationic liposomes (liposome-protamine-DNA, LPD), the PLPD and Tf-PLPD had much less cytotoxicity to three hepatic cell lines (including HepG2, SMMC7721 and Chang' s normal hepatocyte). The results indicated that the Tf-PLPD is a perspective non-viral vector for gene delivery systems.