Optimization of freeze-dried nanoparticles of ginkgolide B by central composite design-response surface methodology and their in vitro release studies / 中草药

Objective: In order to solve the problem of ginkgolide B (GB) for preparing the intravenous injection dosage form, such as it’s low solubility, rapid elimination in vivo and poor stability in long-term storage, a novel biodegradable polysaccharide polymer was used as a carrier to encapsulate GB into nanoparticles with sustained-release profile, which then was freeze dried for keep its stability. Methods: GB nanoparticles (GB-NP) were prepared by coacervation method with hydrophilicity polymer. The Design-Expert 8.0 software was applied for experimental design. The formulation was finalized by investigating the concentration of GB, the mass ratio of GB to polymer, and the pH of the polymer solution with size and polydispersity indexas the evaluation parameters. The optimum formulation and technique were selected by response surface method. Then the nanoparticle suspension was further freeze dried and in vitro release behavior was tested in PBS containing 30% ethanol. Results: The optimum prescription conditions were as follows: the concentration of GB was 1.5 mg/mL, the ratio of GB mass to polymer mass was 0.1 and the polymer solution pH was set at 5.0. The entrapment efficiency was (99.64 ± 0.45)% with the drug loading ratio of (9.04 ± 0.04)%. Average particle size of GB-NP was (192.8 ± 2.8) nm with a preferable PDI of 0.18 ± 0.03. The freeze-drying conditions were described as follows: using 1% mannitol as freeze- drying supporting agent, the solution of GB-NP was pre-frozen for 12 h at −80 ℃ and dried for 24 h at −40 ℃. The release behavior of free GB was rapid with the cumulative release rate reaching (64.74 ± 3.95)% during the first hour, while the cumulative release rate of GB in nanoparticles was (36.90 ± 1.41)% during the first hour. Conclusion: The GB-NP using this special biodegradable polysaccharide polymer can improve GB’s dissolution behavior in water and make GB sustained release in vitro, which is beneficial for preparing GB’s intravenous injection dosage form.

Preparation of lipid membrane-wrapped nanoparticles loaded with metformin polymer and doxorubicin and evaluation of their therapeutic effect on breast cancer / 药学学报

In this study, the lipid membrane-wrapped nanoparticles loaded with metformin polymer (PolyMet) and doxorubicin (DOX) was prepared and then evaluated therapeutic effect on breast cancer. An anionic chain PGA-DOX based on γ-polyglutamic acid (PGA) with DOX was synthesized via amidation reaction and characterized by 1H NMR. The PGA-DOX and PolyMet were loaded via electrostatic attraction to prepare the co-delivery nanoparticles system (PolyMet-DOX-NPs). Then, PolyMet-DOX-NPs were coated with cationic liposome membrane to form the core-membrane structural system (PolyMet-DOX-lipid-nanoparticles, PolyMet-DOX-LNPs). The structure and morphology of PolyMet-DOX-LNPs were observed by transmission electron microscope. The particle size, zeta potential, encapsulation efficiency (EE), drug loading (DL), release behavior in vitro of PolyMet-DOX-LNPs were investigated. The MTT assay was used to examine the cytotoxicity of PolyMet combined with DOX on 4T-1 cells. The 4T1Fluc tumor-bearing mice model was used to evaluate the therapeutic efficacy of PolyMet-DOX-LNPs in vivo. All animal experiments were performed in line with ethical standards and approved by the Animal Experiments Ethical Committee of Zhejiang Chinese Medical University. 1H NMR spectrum showed that PGA-DOX was successfully synthesized with DOX grafting rate of (72.03 ± 1.29) %. The EE and DL of PolyMet-DOX-LNPs was (72.76 ± 1.92) % and (1.16 ± 0.12) %, respectively. PolyMet-DOX-LNPs exhibited a suitable size of (159.3 ± 7.4) nm and positive charge of (+36.3 ± 1.9) mV with good spheroidal morphology and dispersibility. The release profiles in vitro showed that PolyMet-DOX-LNPs exhibited a slowly and maintained release behavior at physiological pH value (pH 7.4) within 48 h. Further studies showed that PolyMet combined with DOX could synergistically enhance the cytotoxicity on 4T-1 cells. Bioluminescence imaging (BLI) result showed that the luminescence signal intensity of 4T-1Fluc cells was reduced after treatment with PolyMet-DOX-LNPs and the tumor volume growth was also inhibited. Additionally, the H&E staining and changes of body weight showed that PolyMet could reduce the toxicity of DOX. To sum up, PolyMet has a good synergistic effect with DOX in the treatment of breast cancer, which provide the foundation for this novel metformin polymer on the anti-tumor application.

Inhibitory effects of Qushuanling Capsule () on thrombus formation and platelet aggregation in rats / 中国结合医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of Qushuanling Capsule ( QSLC) on thrombus formation and platelet aggregation in rats.</p><p><b>METHODS</b>Arteriovenous bypass, venous thrombosis, and middle cerebral artery thrombosis models were used in rats to investigate the anti-thrombotic effects of QSLC, a compound of nine Chinese herbs. The platelet aggregation induced by adenosine diphosphate (ADP), thrombin or arachidonic acid (AA), as well as the contents of thromboxane B(2) (TXB(2)) and 6-keto-prostaglandin F1α (6-keto-PGF1α) in rat plasma and aortic walls, were determined to investigate the possible mechanisms of the anti-thrombotic effects of QSLC.</p><p><b>RESULTS</b>After oral administration with QSLC for 7 days, arteriovenous bypass thrombosis was obviously suppressed compared with the model group, venous thrombosis was also obviously suppressed, rat behaviors were obviously improved, and brain infarct size as well as water content were also reduced. The platelet aggregation induced by ADP or thrombin was inhibited by QSLC, but the drug had no effect on AA-induced platelet aggregation and content of TXB(2) and 6-keto-PGF1α in plasma and the aortic wall.</p><p><b>CONCLUSION</b>These results suggest that QSLC can be used in the prevention and treatment of thrombotic diseases, and that its mechanism of action may be related to inhibition of platelet aggregation.</p>

Therapeutic potential of Naja naja atra venom in a rat model of diabetic nephropathy / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the protective effects of naja naja atra venom (NNAV) in a rat model of diabetic nephropathy (DN).</p><p><b>METHODS</b>The rat diabetes model was induced by intraperitoneal injection of streptozotocin (STZ). Thirty-two model rats were randomly divided into one DN group (n=8) and three treatment groups (n=8 each) that received NNAV at doses of 30, 90, or 270 μg/(kg·day) via oral gavage, another eight rats as normal controls. After 12 weeks, all rats were sacrificed and the changes in serum and urine biological index levels were determined by colorimetric assay. Microalbumin (mALB), N-acetyl-β- glucosaminidase (NAG) and cystatin C (CysC) concentrations were measured by ELISA. Renal tissues were sliced for pathological and immunohistochemical observations.</p><p><b>RESULTS</b>Comparied with the DN group, serum glucose was decreased by 31.04%, total cholesterol 21.96%, triglyceride 23.78%, serum creatinine 19.83%, blood urea nitrogen 31.28%, urinary protein excretion 45.42%, mALB 10.42%, NAG 20.65%, CysC 19.57%, whereas albumin increased by 5.55%, high-density lipoprotein-cholesterol 59.09%, creatinine clearance 19.05% in the treatment group by NNAV administration at dose of 90 μg/(kg·day). NNAV also reduced the levels of malondialdehyde in serum (22.56%) and kidney tissue (9.79%), and increased superoxide dismutase concentration in serum (15%) and decreased it in renal tissue (8.85%). In addition, under light microscopy kidney structure was improved and glomerular hypertrophy decreased by 8.29%. As shown by immunohistochemistry, NNAV inhibited transforming growth factor-β1 by 6.70% and nuclear actor-κB by 5.15%.</p><p><b>CONCLUSION</b>NNAV improves biological indexes in DN, and it may exert renoprotective effects in rats with STZ-induced diabetes.</p>