Effect of nanoparticles of different stiffness combined with menthol/curcumol on mechanical properties of bEnd.3 cells / 中国中药杂志

This study aimed to investigate the effects of nanoparticles PLGA-NPs and mesoporous silicon nanoparticles(MSNs) of different stiffness before and after combination with menthol or curcumol on the mechanical properties of bEnd.3 cells. The particle size distributions of PLGA-NPs and MSNs were measured by Malvern particle size analyzer, and the stiffness of the two nanoparticles was quantified by atomic force microscopy(AFM). The bEnd.3 cells were cultured in vitro, and the cell surface morphology, roughness, and Young's modulus were examined to characterize the roughness and stiffness of the cell surface. The changes in the mechanical properties of the cells were observed by AFM, and the structure and expression of cytoskeletal F-actin were observed by a laser-scanning confocal microscope. The results showed that both nanoparticles had good dispersion. The particle size of PLGA-NPs was(98.77±2.04) nm, the PDI was(0.140±0.030), and Young's modulus value was(104.717±8.475) MPa. The particle size of MSNs was(97.47±3.92) nm, the PDI was(0.380±0.016), and Young's modulus value was(306.019±8.822) MPa. The stiffness of PLGA-NPs was significantly lower than that of MSNs. After bEnd.3 cells were treated by PLGA-NPs and MSNs separately, the cells showed fine pores on the cell surface, increased roughness, decreased Young's modulus, blurred and broken F-actin bands, and reduced mean gray value. Compared with PLGA-NPs alone, PLGA-NPs combined with menthol or curcumol could allow deepened and densely distributed surface pores of bEnd.3 cells, increase roughness, reduce Young's modulus, aggravate F-actin band breakage, and diminish mean gray value. Compared with MSNs alone, MSNs combined with menthol could allow deepened and densely distributed surface pores of bEnd.3 cells, increase roughness, reduce Young's modulus, aggravate F-actin band breakage, and diminish mean gray value, while no significant difference was observed in combination with curcumol. Therefore, it is inferred that the aromatic components can increase the intracellular uptake and transport of nanoparticles by altering the biomechanical properties of bEnd.3 cells.

Oral nano-formulation improves pancreatic islets dysfunction via lymphatic transport for antidiabetic treatment

Type 2 diabetes mellitus (T2DM) therapy is facing the challenges of long-term medication and gradual destruction of pancreatic islet β-cells. Therefore, it is timely to develop oral prolonged action formulations to improve compliance, while restoring β-cells survival and function. Herein, we designed a simple nanoparticle with enhanced oral absorption and pancreas accumulation property, which combined apical sodium-dependent bile acid transporter-mediated intestinal uptake and lymphatic transportation. In this system, taurocholic acid (TCA) modified poly(lactic-co-glycolic acid) (PLGA) was employed to achieve pancreas location, hydroxychloroquine (HCQ) was loaded to execute therapeutic efficacy, and 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) was introduced as stabilizer together with synergist (PLGA-TCA/DLPC/HCQ). In vitro and in vivo results have proven that PLGA-TCA/DLPC/HCQ reversed the pancreatic islets damage and dysfunction, thus impeding hyperglycemia progression and restoring systemic glucose homeostasis via only once administration every day. In terms of mechanism PLGA-TCA/DLPC/HCQ ameliorated oxidative stress, remodeled the inflammatory pancreas microenvironment, and activated PI3K/AKT signaling pathway without obvious toxicity. This strategy not only provides an oral delivery platform for increasing absorption and pancreas targetability but also opens a new avenue for thorough T2DM treatment.

TPGS/hyaluronic acid dual-functionalized PLGA nanoparticles delivered through dissolving microneedles for markedly improved chemo-photothermal combined therapy of superficial tumor

Nanoparticles (NPs) have shown potential in cancer therapy, while a single administration conferring a satisfactory outcome is still unavailable. To address this issue, the dissolving microneedles (DMNs) were developed to locally deliver functionalized NPs with combined chemotherapy and photothermal therapy (PTT).

In vitro study of GOD/Fe3O4 loaded PLGA nanoparticles in the treatment of retinoblastoma / 解放军医学杂志

Objective To evaluate the therapeutic potential of a novel type of Poly (lactic-co-glycolic acid) (PLGA) nanoparticles loaded with glucose oxidase (GOD)/superparamagnetic iron oxide nanoparticles (Fe3O4Nps) on retinoblastoma (RB) cells in vitro. Methods PLGA nanoparticles loaded with GOD/Fe3O4 (PFG) were prepared by double emulsification. Their particle size, potential, external morphology, and internal structure were examined. Particles that made of PLGA (control), PLGA loaded with GOD (PG), and PLGA loaded with Fe3O4 (PF) are served as control. Y79 cells that were incubated with different particles are termed control group, PF group, PG group, and PFG group. After co-incubation with nanoparticles, cell viability, and reactive oxygen species production were detected. Results PLGA nanoparticles loaded with GOD/Fe3O4 were successfully prepared. The form of PLGA nanoparticles was uniform and showed a round shape with a diameter of 299.3 nm. The nanoparticles were engulfed by Y79 cells after co-incubation with Y79 cells, producing a large number of reactive oxygen species. Cytotoxicity test results showed that the cell viability of Y79 cells in PLGA nanoparticle group coated with GOD/Fe3O4 [(53.648±2.565)%] was significantly lower than that in control group [(100.028±4.491)%], PF group [(97.782±17.520)%] or PG group [(87.438±3.537)%](F=21.226, P<0.01); The cell viability of Y79 cells in 0.25 μg/ml PFG nanoparticle group [(51.770±1.529)%] was significantly lower than that in control group [(100.000±5.021)%], 0.0625 μg/ml group [(85.723±6.903)%] and 0.125 μg/ml group [(74.535±8.282)%] (F=34.593, P<0.05). Massive cell death was detected in the PFG group under laser confocal microscope. Conclusions The novel type of PLGA nanoparticles loaded with GOD/Fe3O4 toxic to Y79 tumor cells with a good reactive oxygen generation ability. It provides a potential treatment for RB.

Construction of eukaryotic expression vector of hypoxic inducible VEGF and its in vitro delivery application and functional identification / 解放军医学杂志

Objective To construct the eukaryotic expression vector of hypoxia inducible vascular endothelial growth factor (VEGF), and establish its in vitro delivery method. Methods Erythropoietin (EPO) enhancer was inserted into eukaryotic expression vector pGL4.73 [hRluc/SV40] (pSV) promoter by gene recombination technique to construct hypoxia inducible expression system (pEPO-SV). Renilla luciferase (Rluc) was used as downstream reporter gene. Then the VEGF165 gene was inserted into the pEPO-SV plasmid instead of Rluc, and the pEPO-SV-VEGF and pSV-VEGF expression vectors were obtained by inserting the pEPO-SV-VEGF gene into pSV as control. The pSV plasmid expressing Rluc or VEGF165 and pEPO-SV plasmid were transfected in vitro into human embryonic kidney 293T cells. The expression of Rluc or VEGF165 was used to identify the hypoxia induction function of the constructed vector after being treated under normal and hypoxic conditions for 24h and 48h. The intracellular delivery method of plasmids was then established based on poly (lactic acid-glycolic acid) copolymer (PLGA) nanoparticles as carrier, and the efficiency of the eukaryotic expression plasmids induced by hypoxia was evaluated under the in vitro hypoxia model. Results In the construction of plasmid, the successful insertion and correctness of EPO enhancer and VEGF165 gene were confirmed by restriction endonuclease digestion, PCR amplification and DNA sequencing. The plasmid expressing Rluc or VEGF165 was transfected into 293T cells respectively. There was no significant difference in the expression of reporter gene Rluc (one, plasmid pSV and pEPO-SV fluorescence expression values were 2448.24±158.51 and 3173.97±379.92, the second, plasmid pSV and pEPO-SV fluorescence expression values were 55 500.00±3237.05 and 51 193.18±866.32, respectively) or target gene VEGF165 in normal culture (P>0.05). But the expression of Rluc (In the cobalt chloride of hypoxia, the fluorescence expression values of pSV and pEPO-SV were 4857.70±1223.28 and 16 432.64±1618.73, respectively. In the hypoxia incubator, the fluorescence expression values of pSV and pEPO-SV were 2504.45±213.20 and 17 274.35±685.60, respectively) or VEGF165 in hypoxia was significantly higher than that in control group (P<0.01). The results showed that the constructed pEPO-SV and pEPO-SV-VEGF plasmids had typical hypoxia inducible expression activity. PLGA nanoparticles were used to in vitro deliver pEPO-SV and pSV in 293T cells. The results of detecting the reporter gene Rluc in normal culture and hypoxic conditions were consistent with those mentioned above, that is, under normal conditions, the 24h and 48h fluorescence expression values of plasmids pSV and pEPO-SV were 149.44±4.01 and 127.09±15.05, 1074.91±114.78 and 1064.56±137.48, respectively; under hypoxic conditions, the 24h and 48h fluorescence expression values of pSV and pEPO-SV were 3265.34±440.00 and 8828.87±637.03, 3202.06±33.43 and 9114.75±292.06, respectively. Conclusion A typical hypoxia inducible VEGF eukaryotic expression system has been successfully established, and an in vitro effective delivery method is also established, which may have an important application prospect in ischemia, hypoxia and other tissue injury diseases.

Study on Cellular Uptake Mechanism of HepG2.2.15 Cells to Nanoparticles Co-loaded with Syringopicroside and Hydroxytyrosol / 中国中医药信息杂志

Objective To investigate the uptake mechanism of HepG2.2.15 cells to the nanoparticles co-loaded with syringopicroside and hydroxytyrosol (SH-NPs). Methods The nanoparticles were prepared by using a nanoprecipitation method with mPEG-PLGA as nano-carrier co-loaded with syringopicroside and hydroxytyrosol. The uptake mechanism of HepG2.2.15 cells to SH-NPs was studied by fluorescence microscopy and flow cytometry using fluoresceineisothiocyanate (FITC) as a fluorescent marker. Results With colchicine as the inhibitor, the incubation time ranged from 0.5 to 24 h, the percentage of positive cells increased from 1.9% to 56.4%; When the drug concentration was 125, 250 μg/mL and 500 μg/mL, the positive cell percentages were 4.9%, 3.4% and 3.9%. With chloroquine as the inhibitor; the incubation time ranged from 0.5 to 24 h, the percentage of positive cells increased from 7.4% to 55.4%; When the drug concentration was 125, 250 and 500 μg/mL, the percentage of positive cells was 19.5%, 22.5% and 27.6%. Conclusion Colchicine and chloroquine have an inhibitory effect on HepG2.2.15 cells uptake, and the uptake of SH-NPs in HepG2.2.15 cells was positively correlated with drug concentration and incubation time. It can be concluded that the uptake mechanism of HepG2.2.15 cells to SH-NPs was nonspecific adsorption endocytosis.

In Vitro Release and Inhibiting Effects on the Proliferation of SKOV-3 of Paclitaxel PLGA Nanoparticles Modified with Folic Acid Conjugated Chitosan Oligosaccharide / 中国药师

Objective:To prepare PLGA nanoparticles modified with folic acid conjugated chitosan oligosaccharide containing pa-clitaxel (F-CS-PLGA-NPs) and study the inhibitory effect on SKOV-3. Methods:F-CS-PLGA-NPs were prepared by an interface dep-osition method, 30% ethanol was used as the release medium for the in vitro release profiles of nanoparticles, and MTT was adopted to evaluate the inhibitory effect of paclitaxel with different formulations and concentrations on SKOV-3. Results:The particle size and zeta potential of F-CS-PLGA-NPs was (321 ± 0. 76) nm and (22. 6 ± 0. 26) mV, respectively, the drug loading was (5. 1 ± 0. 25)%, and the encapsulation efficiency was (41. 96 ± 1. 96)%. F-CS-PLGA-NPs had a similar in vitro release profiles with the ordinary nanoparti-cles ( PLGA-NPs) . About 35% of paclitaxel was released from the nanoparticles in the initial 24 h, and then a near zero order release at a relative slow rate was shown, and the cumulative release rate in 144 h was about 75%. The results of cell experiments suggested that at the same paclitaxel concentration, the inhibition effect of F-CS-PLGA-NPs group was stronger than that of the PLGA-NPs group and the solution group. The inhibition effect of F-CS-PLGA-NPs could be reduced by free folic acid. Conclusion:PLGA nanoparticles modified with folic acid conjugated chitosan oligosaccharide can increase the targeting efficiency in SKOVS-3 tumor cells.

Preparation and in vitro evaluation of DMAB-modified PLGA nanoparticles loading tetrandrine / 中草药

Objective: The study aims at preparing the didodecyldimethylammonium bromide (DMAB)-modified PLGA nanoparticles (NPs) loading tetrandrine (Tet) (DMAB-Tet-PLGA-NPs) and investigating the preparation process, physicochemical characterization, in vitro cytotoxicity, and particle cellular uptake. Methods: DMAB-Tet-PLGA-NPs were prepared by the emulsion solvent diffusion method and the preparation process was optimized with the uniform design experiment. The drug loading, entrapment efficiency (EE), and in vitro drug release were studied to evaluate the drug-loading property. The in vitro cytotoxicity against human lung cancer cell A549 was measured by the standard MTT assay. The particles cellular uptake in A549 was evaluated by qualitative and quantitative methods. Results: DMAB-Tet-PLGA-NPs in the mean size of (205.40±2.66) nm with spherical shape and showed positive surface charge. Drug loading and EE were (2.130±0.035)% and (50.780±3.253)%, respectively. DMAB-Tet-PLGA-NPs could retard drug release in pH 7.4 release media and the cumulative release was up to 64.56% over 48 h. And DMAB-Tet-PLGA-NPs showed the significant dose-and time-dependent cytotoxicity of Tet in vitro and well cellular uptake by A549. Conclusion: DMAB-Tet-PLGA-NPs shows the good EE, uniform particle size, and could retard drug release in vitro. And DMAB-Tet-PLGA-NPs shows the significant cytotoxicity in vitro and well cellular uptake by A549.

Interaction of PLGA nanoparticles with HL60 cells by fluorescence tracking / 国际生物医学工程杂志

Objective Nanoparticles are widely investigated and applied in clinical diagnosis and treatment as drug carrier,and their transmembrane process is related to their biological effects.The aim of this study was to investigate the interaction of fluorescein-labeled PLGA nanoparticles and HL60 cells via fluorescence tracking.Methods The transmembrane process of nanoparticles was quantitatively analyzed by laser scanning confocal microscopy.Results The analyzing results showed that the interaction of fluorescein-labeled PLGA nanoparticles and HL60 cells was strongly temperature-dependent.The receptor-mediated endocytosis mechanism played an important role in the transmembrane process for cellular uptake of nanopaticles.Conclusions This study provides a theoretical basis for design and application of nano-medicines.

Ultrasound enhances PLGA nanoparticle-mediated gene delivery in vivo / 中华超声影像学杂志

Objective To investigate the feasibility and the efficacy of ultrasound in promoting PLGA nanoparticle-mediated gene transfection in vivo.Methods Prostate cancer cell line PC-3 was used to generate xenografts in nude mice for gene transfection experiment in vivo.GFP plasmid was encapsulated in PLGA-based nanoparticles.Nanoparticles were injected into tumors locally.Two hours later,xenografts were exposed to ultrasound.Xenograft tissues were harvested in different time points to assess the efficiency of gene expression with regard to different parameters of ultrasound. Results PLGA nanoparticle-encapsulated GFP plasmids were readily transfected to PC-3 cells in vivo.A large number of GFP expressing cells were observed after exposed to ultrasound with 1.0 MHz 50% duty factor continuous wave.In comparison,ultrasound exposure with 40% duty factor pulse wave in vivo had low efficacy in terms of GFP expression.No animal death was noticed due to ultrasound exposure.Conclusions Ultrasound exposure can enhance the release of plasmid DNA content delivered by PLGA nanoparticles in vivo,local exposure to ultrasound wave would be used in conjunction with PLGA nanoparticle-mediated targeted delivery to the tissue or organ of interest.