Preparation of mesoporous silica nanoparticles with different sizes and study on the correlation between size and toxicity / 药学学报

To investigate the crucial role of particle size in the biological effects of nanoparticles, a series of mesoporous silica nanoparticles (MSNs) were prepared with particle size gradients (50, 100, 150, 200 nm) with the traditional Stober method and adjusting the type and ratio of the silica source. The correlation between toxicity and size-caused biological effects were then further examined both in vitro and in vivo. The results indicated that the prepared MSNs had a uniform size, good dispersal, and ordered mesoporous structure. Hemolytic toxicity was found to be independent of particle size. At the cellular level, MSNs with smaller particle sizes were more readily internalized by cells, which initiated to more intense oxidative stress, therefor inducing higher cytotoxicity, and apoptosis rate. In vivo studies demonstrated that MSNs primarily accumulated in the liver and kidneys of mice. Pharmacokinetic analysis revealed that larger MSNs were eliminated more efficiently by the urinary system than smaller MSNs. The mice's body weight monitoring, blood tests, and pathological sections of major organs indicated good biocompatibility for MSNs of different sizes. Animal welfare and the animal experimental protocols were strictly consistent with related ethics regulations of Zhejiang Chinese Medical University. Overall, this study prepared MSNs with a particle size gradient to investigate the correlation between toxicity and particle size using macrophages and endothelial cells. The study also examined the biosafety of MSNs with different particle sizes in vivo and in vitro, which could help to improve the safety design strategy of MSNs for drug delivery systems.

Preparation of mitochondrial targeted calcium arsenite/doxorubicin lipid nanoparticles and the in vitro study in reversing tumor drug resistance / 药学学报

This study aims at the critical role of P-glycoprotein (P-gp) in tumor drug resistance, taking advantage of the adenosine triphosphate (ATP) dependence of P-gp mediated drug transport and efflux across the cell membrane. Mitochondrial targeted calcium arsenite/doxorubicin (DOX) lipid nanoparticles were constructed via hydrothermal method and thin-film dispersion method for reversing tumor drug resistance. The results showed that the lipid nanoparticles were uniform in size and well dispersed with a mean particle size of (261 ± 7) nm, zeta potential of (-9.6 ± 1.3) mV. The DOX loading efficiency and encapsulation efficiency were 22.6% and 84.0%. The in vitro drug release profile was pH-dependent; the drug accumulation at mitochondria was significantly increased, which then caused overload of calcium and inhibition of P-gp and ATP, thereby reversing tumor drug resistance. The simultaneously released arsenite ion and DOX could synergistically kill the tumor cells. In summary, the lipid nanoparticles prepared in this study have uniform particle size, high drug loading efficiency and encapsulation efficiency, excellent colloidal stability, pH responsiveness, and impressive ability to reverse tumor drug resistance, which may hold great potential in further clinical applications.

Advance in research of biodegradable mesoporous silica nanoparticles / 药学学报

Mesoporous silica nanoparticles (MSNs) have been widely used as drug carriers in the diagnosis and treatment of diseases due to their specific characteristics, which include a large surface area, ordered mesoporous structures, easy surface modification and feasible sustained release action for encapsulated drugs. With the research development of MSNs, the biodegradability and removability of mesoporous silica nanomaterials have attracted considerable attention in the clinical application of the MSNs-based formulations. This paper was prepared to emphasize the preparation approaches of biodegradable mesoporous silica nanoparticles through the metal oxide doping method and the organic compound doping method. We discussed the biodegradable mechanism and process of such nanoparticles, and finally, provided an insightful and helpful review of the prospective application of the biodegradable mesoporous silica nanoparticles in medical field.

Preparation process of norcantharidin/tetrandrine dual loaded liposomes and their release characteristics / 中国中药杂志

In order to optimize the prescription and preparation process of norcantharidin/tetrandrine dual loaded liposomes, the dual drug loaded liposomes were prepared by film dispersion-ultrasonic method using norcantharidin-mesoporous silica nanoparticles（MSN-NCTD）and tetrandrine（Tet）. With particle size and encapsulation efficiency as comprehensive indexes, the influences of phospholipid cholesterol amount, ultrasonic time and ultrasonic power on prescription process were investigated by orthogonal test; the release characteristics of liposomes were investigated by dialysis method. The results indicated that the best prescription process of prepared norcantharidin/tetrandrine dual loaded liposomes was as follows: phospholipid-cholesterol ratio 2.5:1, ultrasonic time 4 min, ultrasonic power 40%; the encapsulation efficiency was 86.62% and 79.19%respectively for NCTD and Tet;liposomes were well-shaped under the transmission microscope, with average particle size of （207.5±3.6） nm, Zeta potential of （1.345±0.173） mV; and the 48 h cumulative release rates of NCTD and Tet were 85.14% and 85.00% respectively. The experiment results proved that the dual drug loaded liposomes prepared by film dispersion-ultrasonic method had uniform particle size, high encapsulation efficiency and sustained release characteristics.

Preparation and evaluation of arsenic trioxide glioma targeting drug delivery system loaded by PAMAM dendrimers co-modified with RGDyC and PEG / 中国中药杂志

Arsenic trioxide (ATO) is an effective component of traditional Chinese medicine arsenic. The existing studies have shown its good inhibition and apoptosis ability on a variety of tumours. However, its toxicity and difficulties in the permeability into the blood brain barrier (BBB) has the limitation in the application of glioma treatment. Polyamide-amine dendrimer (PAMAM) is a synthetic polymer with many advantages, such as a good permeability, stability and biocompatibility. Additionally, the 5th generation of PAMAM is an ideal drug carrier due to its three-dimensional structure. In this study, the 5th generation of PAMAM co-modified with RGDyC and PEG, then confirmed by ¹H-NMR. The average particle size of nanoparticles was about 20 nm according to the nanoparticle size-potential analyser and transmission electron microscopy. release showed that the nanocarrier not only has the sustained release effect, but also some pH-sensitive properties. The cell results showed that PAMAM co-modified with RGDyC and PEGAM has a lower cytotoxicity than the non-modified group . Accordingly, the drug delivery system has a better anti-tumour effect across the blood brain barrier (BBB) , which further proves the tumour targeting of RGDyC.

Preparation and in vitro evaluation of borneol and folic acid co-modified doxorubicin loaded PAMAM drug delivery system / 药学学报

A novel targeting drug carrier (FA-BO-PAMAM) based on the PAMAM G5 dendrimer modified with borneol (BO) and folic acid (FA) molecules on the periphery and doxorubicin (DOX) loaded in the interior was designed and prepared to achieve the purposes of enhancing the blood-brain barrier (BBB) transportation and improving the drug accumulation in the glioma cells. 1H NMR was used to confirm the synthesis of FA-BO-PAMAM; its morphology and mean size were analyzed by dynamic light scattering (DLS) and transmission electron microscope (TEM). Based on the HBMEC and C6 cells, cytotoxicity assay, transport across the BBB, cellular uptake and anti-tumor activity in vitro were investigated to evaluate the properties of nanocarriers in vitro. The results showed that the nanocarrier of FA-BO-PAMAM was successfully synthesized, which was spherical in morphology with the average size of (22.28 ± 0.42) nm, and zeta potential of (7.6 ± 0.89) mV. Cytotoxicity and transport across the BBB assay showed that BO-modified conjugates decreased the cytotoxicity of PAMAM against both HBMEC and C6 cells and exhibited higher BBB transportation ability than BO-unmodified conjugates; moreover, modification with FA increased the total uptake of DOX by C6 cells and enhanced the cytotoxicity of DOX-polymer against C6 cells. Therefore, FA-BO-PAMAM is a promising nanodrug delivery system in employing PAMAM as a drug carrier and treatment for brain glioma.

Preparation of curcumin-loaded long-circulating liposomes and its pharmacokinetics in rats / 中国中药杂志

Curcumin has a wide spectrum of pharmaceutical properties such as antitumor, antioxidant, antiamyloid, and anti-inflammatory activity. However, poor aqueous solubility and low bioavailability of curcumin are major challenge in its development as a useful drug. To overcome many of these problems, curcumin-loaded long-circulating liposomes (Cur-LCL) were prepared by the ethanol injection method. Morphology of Cur-LCL was observed by transmission electron microscope, mean particle size and Zeta potential were detected by laser particle size analyzer, entrapment efficiency and drug loading were evaluated by ultracentrifugation. The drug release behavior in vitro and pharmacokinetic behavior in rats of Cur-LCL were investigated with curcumin (Cur) and curcumin liposomes (Cur-Lips) as control. The results showed that the mean diameter of Cur-LCL was 110 nm, the Zeta potential was -5.8 mV. The entrapment efficiency and drug loading of Cur-LCL was 80.25%, 2.06%, respectively. The release behavior in vitro studied by dialysis in PBS buffer showed significant sustained release profile that 48.95% Cur were released from Cur-LCL in 7 h, 88.92% in 24 h. The pharmacokinetic parameters showed that compared with Cur and Cur-Lips, the t(1/2beta) of Cur-LCL was extended to 13 and 1.8-fold, respectively. Besides, the AUC values was significantly increased (P < 0.01), and the clearance was evidently decreased (P < 0.01). These results from in vitro and in vivo indicated that Cur-LCL were able to realize controlled drug release and increase circulation time.

Study on chitosan-modified tripterygium glycoside nanoparticles and its renal targeting property / 中国中药杂志

<p><b>OBJECTIVE</b>To prepare chitosan-modified tripterygium glycoside nanoparticles (LMWC-TG-PLA-NPs), and assess its renal targeting property in rats.</p><p><b>METHOD</b>Chitosan-modified tripterygium glycoside nanoparticles (LMWC-TG-PLA-NPs) were prepared by modified spontaneous emulsification solvent evaporation method, and modified with 50% deacetylated low molecular weight chitosan (LMWC). The shape of nanoparticles was observed under a transmission electron microscope. The mean diameter of nanoparticles was measured by particle size analyzer. The drug encapsulation efficiency and drug loading were measured by centrifuge method. The in vitro release behavior was studied with dialysis bags. Renal microdialysis technique and renal artery administration technique were combined to study the renal targeting property of nanopartcles. LMWC-TG-PLA-NPs were administrated in rats by tail vein injection (TVI) and renal artery administration (RAA), respectively, with TG-PLA-NPs as the control group. Renal dialysis fluid was regularly collected to determine the drug concentration in the dialysis fluid, map drug concentration-time curves, and calculate AUC ratio in kidneys through the two injection approaches as the renal targeting parameter (RTP), in order to assess the renal targeting property of LMWC-TG-PLA-NPs.</p><p><b>RESULTS</b>The prepared LMWC-TG-PLA-NPs looked smooth and round. Their average diameter, polydispersity index, encapsulation efficiency and drug loading were (207.6 +/- 3.4) nm, (0.078 +/- 0.009)%, (61.83 +/- 2.43)%, and (10.70 +/- 0.37)%, respectively. The pH 7.4 PBS buffer solution containing 20% ethanol showed obvious sustained release behavior. LMWC-TG-PLA-NPs showed a RTP of 71.97%, which was 3.6 times of TG-PLA-NPs of the control group.</p><p><b>CONCLUSION</b>The prepared LMWC-TG-PLA-NPs showed high drug encapsulation efficiency and drug loading, with obvious sustained release characteristics and renal targeting property. LMWC-TG-PLA-NPs are expected to become a new type vector for reducing toxic and side effects of tripterygium glycoside. Meanwhile, a new method is established for assessing renal targeting property with AUC ratio in kidneys after administrated through caudal veins and renal arteries as the renal targeting parameter.</p>

Studies on absorption kinetics characteristics of diterpenoid alkaloids in rats after oral administration of Sini Tang powder / 中国中药杂志

The purpose of this study was to investigate the absorption kinetics of aconitine, mesaconitine and hypaconitine in rats after oral administration of Sini Tang powder. With cannulate portal and jugular veins cannulated (double-cannulate), conscious moving rats were orally administered Sini Tang. Then samples of portal and systemic blood were collected at the designated periods of time and analyzed for aconitine, mesaconitine and hypaconitine by HPLC. Apparent absorption coefficient of aconitine, mesaconitine and hypaconitine was caculated respectively. The results indicated that the apparent absorption coefficient of aconitine, mesaconitine and hypaconitine come from Sini Tang were 0. 336, 0. 090, 0. 176, respectively, which had some differences among them. It was also suggested that double-cannulated rat was useful for estimating the absorption kinetics of aconitine, mesaconitine and hypaconitine after orally administered Sini Tang by determining the AUC values for drugs in portal and systemic blood samples. The three alkaloids could all be detected in blood, but the absorption differences were existed among the three alkaloids.

Analysis on the metabolites of mesaconitine in the rat urine by liquid chromatography and electrospray ionization mass spectrometry / 药学学报

The mesaconitine and its major metabolites in the rat urine were identified by liquid chromatography and electrospray ionization tandem mass spectrometry. The rat urine was collected for consecutive 24 hours from the rat following intragastric infusion of mesaconitine, subsequently which were enriched and purified using solid phase extraction. The metabolites of mesaconitine in the rat urine were analyzed by the liquid chromatography and electrospray ionization tandem mass spectrometry. It is shown that the parent drug mesaconitine and its metabolites were found in the rat urine, such as hypo-mesaconitine glucuronic acid conjugate, 10-hydroxy-mesaconitine, 1-O-demethyl mesaconitine, deoxy-mesaconitine and hypo-mesaconitine. Among the five of metabolites, the hypo-mesaconitine glucuronic acid conjugate (m/z 766) was first discovered as the aconitine in rats phase II metabolites, which revealed a new way of mesaconitine metabolism in rats.

Polysorbate-80 modified neurotoxin nanoparticle with its transport and cytotoxicity against blood-brain barrier / 药学学报

This study was aimed at the transport across blood-brain barrier (BBB) of polysorbate-80 modified neurotoxin loaded polybutylcyanoacrylate nanoparticle (P-80-NT-NP) and its cytotoxicity. An in vitro model of BBB using rat brain microvascular endothelial cells (rBMECs) was established. The cytotoxicity of P-80-NT-NP was measured by the MTT assays, where neurotoxin (NT), nanoparticle (NP), neurotoxin nanoparticle (NT-NP) as control, and the permeability of P-80-NT-NP was determined by using of Millicell insert coculture with rBMECs and fluorescence spectrophotometry. MTT results showed that NT, NP, NT-NP and P-80-NT-NP were avirulent to rBMECs when the concentration of NT was lower than 200 ng x mL(-1). But the cytotoxicity of NP, NT-NP and P-80-NT-NP would be augmented accordingly as concentration increased (P < 0.01), causing obvious reductions of cell survival rate, with no significant difference between them (P > 0.05). When the concentration of NT was 150 ng x mL(-1), the permeability on rBMECs of P-80-NT-NP and NT-NP were both significantly higher than that of NT (P < 0.01), and the permeability of P-80-NT-NP was greater than that of NT-NP (P < 0.05). In conclusion, polysorbate-80 modified neurotoxin nanoparticles can transport across the BBB, while concentration of NT is greater than 200 ng x mL(-1), P-80-NT-NP has a little cytotoxicity against rBMECs.

Brain delivery of neurotoxin-I-loaded nanoparticles through intranasal administration / 药学学报

The purpose of this paper is to encapsulate neurotoxin-I (NT-I), a kind of analgesic peptide, into polylactic acid (PLA) nanoparticles (NPs) and to evaluate their transport into the brain after intranasal administration (in) by use of microdialysis sampling technique developed in our laboratory recently. NT-I-NPs (NT-Iradiolabeled with sodium 125I-Iodide) were prepared by a double emulsification solvent evaporation method, and were characterized in terms of surface morphology, particle size distribution, zeta potential and entrapment efficiency. Then, NT-I-NPs were administered intranasally or intravenously to rats and the radioactivities in periaqueductal gray (PAG) were monitored up to 240 min utilizing the microdialysis sampling technique. Nanoparticles prepared were spherical with homogenous size distribution. Their mean particle size and zeta potential measured were (65.3 +/- 10.8) nm and (-28.6 +/- 2.3) mV, respectively. The entrapment efficiency of NT-Iencapsulated into nanoparticles was (35.5 +/- 2.8)%. The brain transport results showed that the time to peak level (Tmax) of NT-I-NPs (in) was (65 +/- 10) min approximately, apparently shorter compared with NT-I-NPs [iv, (95 +/- 10) min] or NT-I [iv, (145 +/- 10) min]. The concentration to peak level (Cmax) and the area under the curves from zero to 4 h (AUC0-4h) of each group followed this order: NT-I-NPs (in) > NT-I-NPs (iv) > NT-I (iv). With nanoparticles as carriers and administered intranasally could be a potential way for centrally active peptides to improve their brain transport. Microdialysis is quite a good technique for the study of drug delivery to the brain.