The effect of the shape of nanocarriers on their transmembrane across Caco-2 cell monolayer / 药学学报

Cerasomes with different shapes were constructed to investigate the effect of the nanocarriers' shape on the cellular uptake and transmembrane capacity. Cerasome-forming lipid (CFL) was synthesized via halogenation, nucleophilic addition and acylation reaction and detected by mass spectrometry and nuclear magnetic resonance spectroscopy. CFL and short chain 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) were employed to prepare organic-inorganic hybrid bicelles in discal shapes (nanodisc) by the thin-film hydration method, and CFL was also used to prepare spherical cerasomes (nanosphere). The particle size and zeta potential of nanocarriers were measured by dynamic light scattering analysis, and the morphology was observed by transmission electron microscopy. With human colon cancer cell line Caco-2 as the model, the effect of the shape of nanocarriers on cellular uptake and transmembrane capacity was investigated qualitatively by confocal laser scanning microscope (CLSM), and the transmembrane capacity was analyzed quantitatively by high performance liquid chromatography (HPLC). The results showed that nanosphere and nanodisc had similar particle diameters around 110 nm and similar zeta potential around -25 mV, with regular morphology under transmission electron microscope. The cellular uptake rate of nanodisc was significantly higher than that of nanosphere in 20 minutes. Further research on Caco-2 cell monolayer demonstrated that nanodisc with faster uptake had less accumulation in the monolayer, which means it had a higher transmembrane rate on Caco-2 cell monolayer and the transmembrane capacity of the nanodisc was better than that of nanosphere within 2 h. These results suggest that rational design of the shape of nanocarriers is expected to regulate nano-bio interactions, promote the transmembrane transport of nanocarriers, and improve the drug absorption.

Safety and efficacy of polycaprolactone copolymer nanosphere hydrogel injected into the scalp dermal tissue of rats

BACKGROUND: Currently, dermal fillers need to be 25 µm or larger to reduce in vivo degradation by macrophages. However, the large size of fillers may cause side effects, including interruption of blood flow and nodule formation. Therefore, using rats, we tested a polycaprolactone copolymer hydrogel with nanoscale particles that could maintain a low in vivo degradation rate. METHODS: Thirty-six 6-week-old Sprague-Dawley rats were divided into group A (normal saline), group B (polycaprolactone microsphere filler), and group C (polycaprolactone copolymer nanosphere hydrogel). The corresponding materials were injected into the dermal layer of the scalp of the rats. At 4, 8, and 12 weeks after injection, blood biochemical and kidney and liver histological analyses were performed. Tissues were examined using hematoxylin-eosin staining to observe tissue infiltration of materials. Collagen formation in the dermal tissue of the scalp was observed with Masson trichrome staining and the collagen content was quantified using a soluble collagen assay kit. RESULTS: The histologic examination for organ infiltration showed no abnormal findings. All blood test results were within the normal ranges. The amount of collagen at 12 weeks increased by 1.22 mg/g in group C and by 0.6 mg/g in group B. CONCLUSIONS: The results reveal that the nanosphere complex near the injection site induced collagen formation. Regardless of the sphere size, aggregation of the copolymer prevented macrophage phagocytosis. The polycaprolactone copolymer nanosphere hydrogel was effective for more than 3 months when injected in the scalp dermal tissue of Sprague-Dawley rats and can be used safely.

The formulation and characterization of near infrared-mediated size reversible ultrasound contrast agent / 药学学报

The drug-loaded ultrasound (US) contrast nanoparticles, which can effectively accumulate in the tumor to penetrate into its deep section, were prepared. After being heated or under the near infrared (NIR) light irradiation, the size of nanoparticles would transform from nanometer-scale to micrometer-scale in vitro, which can vastly enhance the effect of US imaging. We evaluated the size changes of the nanoparticles in vitro, investigating their effect in ultrasound imaging and distribution in vivo. Liposomes containing hydrophobic modified hollow gold nanospheres (HAuNS), doxorubicin (DOX) and perfluorohexane (PFH), which were referred to DOX and HAuNS loaded PFH liposome (DHPL), were prepared by thin film evaporation and ultrasonic technique. The morphology and size of DHPL were measured by transmission electron microscopy and particle size analyzer with dynamic light scattering (DLS) method. The agar gel pore model was used to investigate the enhanced effect of nanoparticles in vitro US imaging under the NIR light irradiation. The biodistribution of DHPL in 4T1 tumor-bearing mice after intravenous injection was measured by the in vivo imaging system. The DHPL were spherical at a particle size of 302 ±5 nm and polydispersity index of 0.195 ±0.018. The HAuNS loaded on phospholipid membrane was observed in transmission electron microscope (TEM) image. Under the NIR light irradiation (1 or 2 W·cm-2), the temperature of the solution containing the DHPL (0.2, 0.04, 0.02 g·L-1 in terms of HAuNS) rose rapidly. And a certain amount of micrometer-sized particles could be detected by the particle size analyzer when the temperature of the analyzer was raised to 52℃. The abundant microbubbles, which would enhance the effect of US imaging, were detected by ultrasonic diagnostic apparatus when the nanoparticles were irradiated by NIR light in the in vitro US imaging experiment. The in vivo distribution experiment showed that the DHPL could effectively accumulate in the tumor due to the enhanced permeability and retention effect (EPR effect) of the tumor. In this study, we successfully made a nanometer-micrometer reversible nanoparticles that can accumulate inside the tumor to provide a feasible scheme for US imaging in the tumor site and the combinational photothermal-chemotheraphy simultaneously.

Matrix stiffness regulates cell uptake of nanoparticles in 2D and 3D cultures of breast cancer cells / 药学学报

Fluorescent polystyrene nanospheres (PS) were used to explore the impact of substrate stiffness on cell uptake of nanoparticles in the breast cancer cells. Polyacrylamide (PAA) gels with varying stiffness were prepared by photopolymerization, and type I rat tail collagen was covalently conjugated on the surface of PAA gels to facilitate cell adhesion. Type I rat tail collagen was also used to fabricate collagen gels for 3D cell culture. Cells of human breast cancer cell line MCF-7 were incubated in the 2D culture on PAA gels and 3D culture within collagen gels. Next, nanospheres of 20 nm and 50 nm polystyrene were applied to MCF-7 cells in the 2D or 3D cultures. Cell morphology and uptake efficiency were observed with confocal microscopy. Our study demonstrates that substrate stiffness differentially regulated the cell morphology as well as the cell uptake behavior of polystyrene nanospheres in MCF-7 cells under 2D or 3D culture conditions.

Preparation and evaluation of new cyanoacrylate nanosphere with alcoxyle side group for gene delivery / 国际药学研究杂志

Objective To prepare a new(alcoxyle cyanoacrylate)-based nanosphere for brain targeting gene delivery and evaluate its physicochemical properties,capability of delivery of transforming growth factor beta 2(TGF-β2)antisense oligonucle?otides(ASON),and its potential use on tumor cell suppression in vitro.Methods The cationic nanospheres(NS)were prepared by emulsion polymerization method with DEAE-dextran as cationic stabilizer.The ASON were adsorbed by charge interaction,and poly?sorbate-80 was used as brain-targeting modification.The morphology was observed by transmission electron microscopy(TEM).The average particle size and Zeta potential were determined by dynamic light scattering(DLS). The ultraviolet spectrophotometry was used to determine the entrapment efficiency and drug loading.Agarose gel electrophoresis was used to analyze the optimal loading ratio of ASON-NS,and also the protection of ASON in DNaseⅠand serum containing environment.The release rate of ASON was deter?mined by dialysis.The cytotoxicity on L929 cells and the anti-tumor activity on A172 cells were evaluated by MTS.Results The TEM showed a typical round nanospheres morphology,and no adhesion was detected.The particle size was(79.04±4.33)nm,the disper?sion coefficient was 0.04 ± 0.03,the Zeta potential was(33.60 ± 0.60)mV. The encapsulation efficiency of ASON-NS was(83.14 ± 1.90)%,and the drug loading of ASON-NS was(11.59±0.56)%.The NS provided ASON protection against the Dnase I and serum containing environment. The NS-ASON could effectively deliver ASON into A172 cells and show anti-tumor activity. Besides,little L929 cytotoxicity was detected.Conclusion A new cyanoacrylate nanosphere with alcoxyle side group for brain targeting gene deliv?ery was prepared successfully. It had good ASON loading and delivery capability,providing new carrier materials for nucleic acid drugs.

Preparation and anti-carcinoma effect of magnetic polybutylcyanoacrylate nanosphere loaded with aclacinomycin A / 中华消化杂志

Objective To prepare magnetic polybutylcyanoacrylate (PBCA) nanosphere loaded with aclacinomycin A (ACM) and investigate its anti carcinoma effect and toxicity. Methods Magnetic PBCA nanospheres loaded with ACM were prepared by interfacial polymerization method. Female BABL/c nude mice were injected with MKN 45 gastric carcinoma cell line mass subcutaneously near right forefoot to establish human gastric carcinoma model. The mice were divided into 5 groups with 6 mice in each group: ACM (8 mg/kg), nanosphere with low dosage of ACM(1.6 mg/kg), nanosphere with high dosage of ACM (8 mg/kg ), magnetic nanosphere without ACM and normal saline (NS). Magnets (2500 Gs) were embedded in the tumor mass of all the mice one day before the date of therapy. The agents were administered again the same as the first time after 5 days. Tumor weight was measured and assay of colony forming unit granulocyte and macrophage (CFU GM) was performed on semi solid culture. Results The drug content of the agent was 12.0% and the mean particle size was 210 nm. The tumor inhibition rates of ACM, nanosphere with low dosage of ACM, nanosphere with high dosage of ACM and carrier without ACM on human gastric carcinoma in nude mice were 22.63%, 30.66%, 52.55% and 10.22% respectively. The average tumor weight of targeted nanospheres group was much lower than that of the same dosage of non targeted ACM group( P

Studies on cetyl-chitosan nanosphere as carriers for paclitaxel / 中草药

Object To prepare and study a suitable carrier for paclitaxel in water. Methods Cetyl chitosan (CTCS), prepared by reacting chitosan (CS) with chlorocetane under alkaline condition, was soluble and spontaneously formed nanosphere about 100 nm in diameter. And the release in vitro from paclitaxel loaded CTCS nanosphere was measured in phosphate buffer solution (PBS, pH=7 4). Results The balanced release concentration of paclitaxel was deceased and half release time (t 1/2 ) was delayed with the increase of substitution degree of alkyl. Conclusion This kind of nanosphere is an excellent carrier for paclitaxel in water.