[The inhibitive effects of 5-fluorouracil-loaded polylactic acid nanoparticles on human Tenon's capsule fibroblast in vitro].

OBJECTIVE: To investigate the inhibitive effects of 5-fluorouracil-loaded polylactic acid nanoparticles (5-FU-PLA-NPs) on human Tenon's capsule fibroblasts in vitro. METHODS: This paper was experimental study. MTT assay was performed to estimate the effects of 0.1 mg/L, 1.0 mg/L, 10.0 mg/L, 100.0 mg/L, 1000.0 mg/L unloaded polylactic acid nanoparticles (PLA-NPs) on fibroblasts proliferation on 48 h, 72 h. MTT assay was performed to estimate the effects of 0.1 mg/L, 1.0 mg/L, 10.0 mg/L, 100.0 mg/L, 1000.0 mg/L original 5-FU and 5-FU-PLA-NPs on fibroblasts' proliferation on 7 consecutive days respectively. The inhibitory rate of the two drugs against the fibroblasts was calculated. Cells were exposed to 100 mg/L original 5-FU and 5-FU-PLA-NPs respectively for 7 days. Semi-quantitative RT-PCR was used to observe the mRNA expression of type III procollagen at the 1st day, 5th day and 7th day. RESULTS: PLA-NPs had no cytotoxicity on the fibroblasts. Both 5-FU-PLA-NPs and original 5-FU could inhibit the proliferation of the fibroblasts and make the expression of type III procollagen mRNA lower in dose-dependent and time-dependent manner. The inhibitive effect of original 5-FU was more effective than 5-FU-PLA-NPs in the initial period, but the inhibitive effect of 5-FU-PLA-NPs was more effective than original 5-FU in long time. CONCLUSION: PLA has good biocompatibility and safety, and can be used as a carrier of ophthalmic drugs. 5-FU-PLA-NPs shows slow-releasing function. 5-FU-PLA-NPs can be proposed as a potential controlled and targeted ophthalmic delivery system for the treatment of antifibrosis after glaucoma filtering surgery.

Preparation, physicochemical characterization and cytotoxicity in vitro of gemcitabine-loaded PEG-PDLLA nanovesicles.

AIM: To investigate the preparation, physicochemical characterization and cytotoxicity in vitro of Gemcitabine-loaded poly(ethylene glycol)-block-poly(D,L-lactide) (PEG-PDLLA) nanovesicles. METHODS: The nanovesicle carriers were prepared from the amphiphilic block copolymer of PEG-PDLLA by a double emulsion technique, and gemcitabine was used as the model drug. The morphology of the nanovesicles was determined by scanning and transmission electron microscopy, and the drug content, drug entrapment and drug-release curve in vitro were detected by UV-Vis-NIR spectrophotometry. Cytotoxicity in the human pancreatic cancer cell line SW1990 was tested by 3-(4,5-dimethyl) ethiazole (MTT) assay. RESULTS: The gemcitabine-loaded nanovesicles were hollow nanospheres with a mean size of 200.6 nm, drug loading of 4.14% and drug embedding ratio of 20.54%. The nanovesicles showed excellent controlled release that was characterized by a fast initial release during the first 72 h, followed by a slower and continuous release. The MTT assay demonstrated that gemcitabine-loaded nanovesicles exhibited dose-dependent and time-delayed cytotoxicity in the human pancreatic cancer cell line SW1990. CONCLUSION: Gemcitabine-loaded PEG-PDLLA nanovesicles prepared by a double emulsion technique exhibited good performance for controlled drug release, and had similar cytotoxic activity to free gemcitabine.

[Preparation of As2O3 nanoparticles and its drug release characteristics in vitro].

OBJECTIVE: To prepare arsenic trioxide (As2O3)-loaded biodegradable polylactic-co-glycolic acid (PLGA) nanoparticles (NPS) and evaluate the glomeration ability, appearance, structure, surface and release characteristics of the NPs. METHODS: With PLGA as the carrier material, As2O3 NPs (As2O3-NPS) were prepared with the method of matrix and ultrasound emulsification. According to the criteria of the diameter of the NPs, drug loading (DL) and embedding ratio (ER), the process of NP preparation was optimized by scanning electron microscopy (SEM), ultraviolet spectroscopy (UV), and XPS. RESULTS: The As2O3-NPS prepared were uniformly spherical with an average diameter of 210-/+23 nm, DL of 29.6% and ER of 82.1%. The drug release assay in vitro showed a sustained drug-release capacity of the preparation. CONCLUSION: As2O3-NPS may serve as a carrier of As2O3 to change the pharmacokinetics of As2O3 in vivo, allow slow drug release, and prolong the drug circulation time after intravenous injection, thereby producing better antitumor effects.

[Biodistribution of (99m)Tc-labeled anti-VEGF mAb 5-FU loaded polylactic acid nanoparticles in human gastric carcinoma xenografts].

OBJECTIVE: To prepare (99m)Tc-labeled Anti-VEGF mAb 5-FU loaded polylactic acid nanoparticles ((99m)Tc-Ab-5-FU-NPs) and investigate its biodistribution in human gastric carcinoma xenografts. METHODS: (99m)Tc-Ab-5-FU-NPs were prepared by labeling Ab-5-FU-NPs with (99m)Tc using improved Schwarz method. After isolation of (99m)Tc-Ab-5-FU-NPs using SephadexG250 column, the labeling ratio and radiochemical purity were determined using chromatography. The immunocompetence of (99m)Tc- Ab-5-FU-NPs was detected by ELISA and immunohistochemistry. (99m)Tc-Ab-5-FU-NPs were then injected via the tail vein into SCID mice bearing human gastric carcinoma, and (99m)Tc labeled mice-derived monoclonal IgG loaded polylactic acid nanoparticles were used as the control, followed by radioimmunoscintigraphic imaging at 2 and 6 h. The radioactive count and radioactive ratio of the tumor and non-tumor tissue (T/NT) in the animal models were calculated using ROI technique. After imaging at 24 h, SCID mice were sacrificed and the radioactive distribution, the %ID/g, as well as the T/NT radioactive ratio were examined, respectively. The concentrations of 5-FU in the tumor and blood were also detected using HPLC method. RESULTS: The labeling ratio of (99m)Tc-Ab-5-FU-NPs was 90%-95%. (99m)Tc-Ab-5-FU-NPs were detected in the tumor tissues by radioimmunoimaging 2 h after the injection. ID%/g in the tumor tissues at 2 and 6 h were both significantly higher than that of the control group. Both the ID%/g in tumor tissues and radioactive ratio of tumor and blood at 6 h were higher than those at 2 h, and the concentration of 5-FU in experimental group increased continuously with time and was significantly higher than that in control group. CONCLUSIONS: (99m)Tc-Ab-5-FU-NPs prepared in this study can meet the demands of radioimmunoimaging, and the anti-VEGF monoclonal antibody possesses reliable immune targeting ability. Six hours after injection, (99m)Tc-Ab-5-FU-NPs can specifically accumulate in the tumor tissues in human gastric carcinoma xenografts at high concentration.

[Study of the anti-tumor effect of anti-vascular endothelial growth factor McAb 5-fluorouracil loaded polylactic acid nanoparticles].

OBJECTIVE: To explore the anti-tumor efficacy of anti- vascular endothelial growth factor (VEGF) McAb 5-fluorouracil (5-FU) loaded polylactic acid (PLA) nanoparticles (NPS) in human gastric carcinoma xenografts of nude mice. METHODS: Anti-VEGF McAb 5-FU loaded PLA NPS were made by ultrasound emulsification. Nude mice model of human gastric carcinoma xenografts was established. Therapeutic effects of drugs on human gastric carcinoma xenografts and side effects concerned were observed. RESULTS: The tumor inhibition rates of control group, nanosphere without 5-FU group, 5-FU (20 mg/kg) group, anti-VEGF McAb nanosphere without 5-FU group, anti-VEGF McAb group, nanosphere with 5-FU group, 5-FU (20 mg/kg) combined with anti-VEGF McAb group, anti-VEGF McAb 5-FU loaded nanosphere group was 0, 6.61%, 24.26%, 27.94%, 35.29%, 37.50%, 39.71% and 52.21% respectively, and there were no significant differences between anti-VEGF McAb 5-FU loaded nanosphere group and nanosphere group without 5-FU in WBC count, serum alanine transferase level or creatinine level. Compared with control group and anti-VEGF McAb 5-FU loaded nanosphere group, the 5-FU group decreased by 34.43% and 37.38% respectively in WBC count (P< 0.05), and increased by 93.17% and 66.56% respectively in alanine transferase. There were significant differences between experimental groups and control group in apoptosis index, especially between anti-VEGF McAb 5-FU loaded nanosphere group and control group (P< 0.05). The microvessel density (MVD) of experimental groups containing anti-VEGF McAb was significantly lower than that of control group or groups containing 5-FU (P< 0.05). CONCLUSION: Anti-VEGF McAb 5-FU loaded nanosphere can increase the tumor inhibitory rate of 5-FU, induce apoptosis by inhibiting tumor angiogenesis with less side effect, and then enhance therapeutic effect, which indicate its potential as a novel, safe nano-tumor-targeting drug.

[Preparation and release efficiency of polylactic acid nanoparticle].

BACKGROUND & OBJECTIVE: As a new drug delivery carrier, medical nanoparticle (NP) appears to be very promising and are widely studied. Compare with microparticle, nanoparticle possesses several advantages, such as ultramicroscopic size, could be ingested by the cells after crossing the tissue matrix, and can penetrate the arterial wall and cross the blood-brain barrier. This study was to prepare polylactic acid (PLA) nanoparticle, and observe its morphology, diameter, structure, surface elements, and ability of in vitro drug release. METHODS: The biodegradable PLA was used as the carrier, and 5-fluorouracil (5-FU) was used as the model drug. 5-FU-PLA nanoparticle (5-FU-PLA-NP) was prepared by matrix and ultrasound emulsification. Morphology of 5-FU-PLA-NP was observed under scanning electron microscope; its surface elements were detected by X ray photoelectron spectroscopyû its drug loading (DL), embedding ratio (ER), and ability of in vitro drug release were assessed by ultraviolet spectroscopy. RESULTS: The nanoparticle was uniformly spherical with average diameter of (191+/-17) nm, DL of 15.2%, and ER of 45.6%. The nanoparticle showed sustained release character in the experiment of in vitro drug release: the cumulative drug release rate in analog body fluid was 94.3% at the 10th day. CONCLUSION: PLA-NP may serve as a carrier of 5-FU, and can change the pharmacokinetics of 5-FU, slower down drug release; 5-FU-PLA-NP can be prepared as intravenous injection, and may prolong the in vivo circulation time of 5-FU, so as to play more efficient antitumor effects.