Growing attention has been given to the potential of pulmonary route as an alternative for non-invasive systemic delivery of therapeutic agents. In this study, novel nebulizer-compatible solid lipid nanoparticles (SLNs) for pulmonary drug delivery of insulin were developed by reverse micelle-double emulsion method. The influences of the amount of sodium cholate (SC) and soybean phosphatidylcholine (SPC) on the deposition properties of the nanoparticles were investigated. Under optimal conditions, the entrapment delivery (ED), respirable fraction (RF) and nebulization efficiency (NE) of SLNs could reach 96.53, 82.11 and 63.28%, respectively, and Ins–SLNs remained stable during nebulization. Fasting plasma glucose level was reduced to 39.41% and insulin level was increased to approximately 170IU/ml 4 h after pulmonary administration of 20 IU/kg Ins–SLNs. A pharmacological bioavailability of 24.33% and a relative bioavailability of 22.33% were obtained using subcutaneous injection as a reference. Incorporating fluorescent-labelled insulin into SLNs, we found that the SLNs were effectively and homogeneously distributed in the lung alveoli. These findings suggested that SLNs could be used as a potential carrier for pulmonary delivery of insulin by improving both in vitro and in vivo stability as well as prolonging hypoglycemic effect, which inevitably resulted in enhanced bioavailability.

Growing attention has been given to the potential of pulmonary route as an alternative for non-invasive systemic delivery of therapeutic agents. In this study, novel nebulizer-compatible solid lipid nanoparticles (SLNs) for pulmonary drug delivery of insulin were developed by reverse micelle-double emulsion method. The influences of the amount of sodium cholate (SC) and soybean phosphatidylcholine (SPC) on the deposition properties of the nanoparticles were investigated. Under optimal conditions, the entrapment delivery (ED), respirable fraction (RF) and nebulization efficiency (NE) of SLNs could reach 96.53, 82.11 and 63.28%, respectively, and Ins-SLNs remained stable during nebulization. Fasting plasma glucose level was reduced to 39.41% and insulin level was increased to approximately 170IU/ml 4 h after pulmonary administration of 20IU/kg Ins-SLNs. A pharmacological bioavailability of 24.33% and a relative bioavailability of 22.33% were obtained using subcutaneous injection as a reference. Incorporating fluorescent-labelled insulin into SLNs, we found that the SLNs were effectively and homogeneously distributed in the lung alveoli. These findings suggested that SLNs could be used as a potential carrier for pulmonary delivery of insulin by improving both in vitro and in vivo stability as well as prolonging hypoglycemic effect, which inevitably resulted in enhanced bioavailability.

We have synthesized a renal-specific drug carrier, 14-succinyl triptolide-lysozyme (TPS-LZM) conjugate for targeted delivery of TP to the PTECs. TPS-LZM could be taken up by HK-2 cells, free TP would be degraded and released, mainly from basolateral side of the cells. Compared with TP, the overall targeting efficiency (TE) of TPS-LZM was significantly enhanced from 11.74% to 95.54% and its MRT was moderately prolonged from 3.08 h to 4.10 h. At very low concentration, TPS-LZM could significantly reverse the disease progression in renal ischemia-reperfusion (I/R) injury animal models, while the mixture of free TP and LZM was ineffective. Further, TPS-LZM conjugate presented much lower hepatotoxicity (0.78 folds lower than TP) and no adverse effect on the immune (1.13 folds higher than TP) and genital system. Thus, TPS-LZM represents a very effective drug candidate for specific treatment of immunological renal diseases with low adverse side effect.

Purpose: To prepare EGFP-TK (enhanced green fl uorescent protein-thymidine kinase) gene nanoparticles and investigate the expression in hepatocarcinoma cells. Methods: Biodegradable and biocompatible polymer PLGA was used to prepare nanoparticles by the doubleemulsion evaporation technique and the characteristics of the nanoparticles were investigated, including morphology, and entrapment effi ciency. The expression of EGFP in human hepatocarcinoma SMMC-7221 cells and human normal parenchymal Chang liver cells was assessed by fl ow cytometric analysis and confocal laser scanning microscopy. The expression of TK gene was investigated by the Trypan blue cell counting method which was able to determine the cells dying after the addition of the drug gancyclovir (GCV). Results: The resulting nanoparticles had a regular spherical surface and a narrow particle size with a mean diameter of 72 nm. The average entrapment effi ciency was 91.25%. The EGFP and TK gene expression of DNA-PLGA-nanoparticles was much higher than that of naked DNA. It was able to protect plasmid while prolonging its release. Conclusions: The enhanced transfection effi ciency and greater ability to prolong the release of plasmid DNA are due to the nanoparticle encapsulation.

Biodegradable monomethoxy (polyethyleneglycol)-poly (lactide-co-glycolide)-monomethoxy (poly-ethyleneglycol) (PELGE) copolymers were synthesized by ring-opening polymerization to formulate plasmid DNA loaded nanoparticles. A double emusion method with polyvinyl alcohol as the emulsifier in the external aqueous phase was employed to prepare nanoparticles. The effects of monomethoxypoly (ethyleneglycol) (mPEG) segments in the polymer on particle size, zeta potential, encapsulation efficiency and in vitro release were investigated. It was found that the introduction of a certain amount of hydrophilic mPEG segments in the copolymer chains could improve the affinity of copolymer with plasmid DNA and enhance the emulsification ability of the copolymer. Thus DNA loaded nanoparticles with smaller particle sizes and higher encapsulation efficiencies were obtained by using PELGE copolymer as the matrix.

目的:对载自杀基因聚丙交酯乙交酯纳米粒的制备工艺进行考察,并评价其体外质量。方法:以聚丙交酯乙交酯为载体材料,采用复乳溶媒蒸发法制备载pEGFP-TKAFB重组质粒纳米粒,并对其形态、包封率、体外释放、抗核酸酶抗超声的能力等进行研究。结果:纳米粒形态圆整、大小均匀,平均粒径为72nm,平均包封率为91.5%,体外释药速度依赖于载体材料的分子量,质粒制成纳米粒后对抗超声剪切及核酸酶降解的能力增强。结论:本纳米粒制备工艺简单,质量可控。

Nanoparticles formulated from polylactic-coglycolic acid (PLGA) polymer loading a new recombinant plasmid pEGFP-TKAFB (TK-PLGA-NPs) were prepared by a double-emulsion evaporation technique. Both in vitro and in vivo release behaviors of TK-PLGA-NPs (with particle diameter ranged from 50 to 100 nm) were investigated, using ethidium bromide (EB) staining and gamma scintigraphy, respectively. The results indicated that the in vitro release rate of DNA (pEGFP-TKAFB plasmid) in TK-PLGA-NPs showed good fit into the Higuichi Equation and dependence in the molecular weight of PLGA polymer. 0.5 h after injection of nanoparticles containing 32P labeled pEGFP-TKAFB plasmid (32P-TK-PLGA-NP) via caudal vein of the mice, the ratio of radioactivity intensity in the liver to total intensity was above 70%, which showed a 1.4-fold increase over that by injection of 32P labeled Pegfptkafb plasmid (32pEGFP-TKAFB plasmid, 32P-TK). Similarly, 2 h after hypodermic injection of 32P-TKPLGA-NPs in mice, the ratio of radioactivity in the liver against total radioactivity was more than 70%, which was 1.6-fold compared with naked 32P-TK. All these data showed that the TK-PLGA-NPs has the potential for livertargeting and delayed drug release.

AIM To prepare valaciclovir polybutylcyanoacrylate nanopa rticles (VACV-PBCA-NP) with liver targeting and hepatocyte permeable characte ristics. METHODS Emulsion polymerization method was employed to prepare VACV-PBCA-NP. The formula and preparation conditions were optimized by using the uniform design. The organ distribution of the intravenously injected VACV-PBCA-NP and VACV in animal was determined using HPLC. The hepatocytes permeability of VACV-PBCA-NP was demonstrated by cell uptake experiment in vitro. RESULTS The drug loading and the drug embedding ratio of VACV-PBCA-NP were 11.20% and 84.85% respectively, with an average diameter of 10 4.77nm±11.78nm. The releasing characteristics in vitro fitted the two-phase kinetics. 74.49% of the drug was found to localize in the liver 15min after the administration of VACV-PBCA-NP in the mice. Compared with VACV, VACV-PBCA-NP showed distinct characteristic of sustained-release in vivo and the drug entering hepatocytes were also greatly increased. CONCLUSION VACV-PBCA-NP has the characteristic of liver targeting and can increase the permeability of VACV to hepatocytes.

AIM: To prepare thymidine kinase gene (TK gene) nanoparticles and to investigate the expression of TK gene. METHODS: Poly (D,L-lactic-co-glycolic acid) (PLGA), a biodegradable and biocompatible polymer, was used to prepare recombinant plasmid PEGFP-AFP nanoparticles by a double-emulsion evaporation technique. Characteristics of the nanoparticles were investigated in this study, including morphology, entrapment efficiency, and tissue distribution. The expression of TK gene was also investigated by MTT assay, by which the viable cells were determined after the addition of ganciclovir (GCV). The enhanced green fluorescent protein (EGFP) expression in human hepatocellular carcinoma SMMC-7721 cells and normal parenchymal Chang liver cells were assessed by flow cytometry. RESULTS: The prepared plasmid-nanoparticles had regular spherical surface and narrow particle size span with a mean diameter of 72±12 nm. The mean entrapment efficiency was 91.25%. A total of 80.14% DNA was found to be localized in the livers after 1-h injection with 32P-DNA-PLGA nanoparticles in mouse caudal vein. The expression of DNA encapsulated in nanoparticles was much higher than that in naked DNA, and human hepatocellular carcinoma SMMC-7721 cells were more sensitive to GCV than human normal parenchymal Chang liver cells.

Purpose: To prepare EGFP-TK (enhanced green fl uorescent protein-thymidine kinase) gene nanoparticles and investigate the expression in hepatocarcinoma cells. Methods: Biodegradable and biocompatible polymer PLGA was used to prepare nanoparticles by the doubleemulsion evaporation technique and the characteristics of the nanoparticles were investigated, including morphology, and entrapment effi ciency. The expression of EGFP in human hepatocarcinoma SMMC-7221 cells and human normal parenchymal Chang liver cells was assessed by fl ow cytometric analysis and confocal laser scanning microscopy. The expression of TK gene was investigated by the Trypan blue cell counting method which was able to determine the cells dying after the addition of the drug gancyclovir (GCV). Results: The resulting nanoparticles had a regular spherical surface and a narrow particle size with a mean diameter of 72 nm. The average entrapment effi ciency was 91.25%. The EGFP and TK gene expression of DNA-PLGA-nanoparticles was much higher than that of naked DNA. It was able to protect plasmid while prolonging its release. Conclusions: The enhanced transfection effi ciency and greater ability to prolong the release of plasmid DNA are due to the nanoparticle encapsulation.