Relationship between BNIP3L and mitochondrial dysfunction in hippocampus of mice with sepsis-associated encephalopathy / 中华麻醉学杂志

Objective:To evaluate the relationship between B-cell lymphoma/adenovirus E1B19 kDa-interacting protein 3-like protein (BNIP3L)/adenovirus E1B-interacting protein and mitochondrial dysfunction in the hippocampus of mice with sepsis-associated encephalopathy (SAE).Methods:One hundred and eighty C57BL/6J mice, aged 6-8 weeks, weighing 20-25 g, were divided into 4 groups ( n=45 each) using a random number table method: control group (C group), sham operation group (Sham group), SAE group, and SAE+ BNIP3L agonist carfilzomib group (SC group). The sepsis model was developed by cecal ligation and puncture (CLP) in anesthetized animals. In SC group, carfilzomib 2 mg/kg was intraperitoneally injected at 2 h after CLP. Twenty mice in each group were selected, and the survival at 7 days after operation was recorded. Eight surviving mice in each group were selected at 1 week after CLP for Morris water maze test. The remaining mice were sacrificed at 24 h after surgery, and the hippocampal tissues were harvested for determination of the expression of BNIP3L (by immunofluorescence) and BNIP3L in mitochondrial protein (by Western blot) and for microscopic examination of the morphological structure of mitochondria. The mitochondrial ATP content was measured by fluorescein-fluorescence enzyme luminescence method, and the mitochondrial membrane potential (MMP) was measured by fluorescence spectrophotometry. Results:Compared with C and Sham groups, the survival rate was significantly decreased, the escape latency was prolonged, the time of staying at the original platform quadrant was shortened, and the number of crossing the original platform region was decreased, the expression of BNIP3L in the hippocampal mitochondria was down-regulated, the MMP and content of mitochondrial ATP were decreased ( P<0.05), the intensity of fluorescence of BNIP3L in the hippocampus was decreased, and the damage to mitochondrial ultrastructure was marked in SAE group. Compared with SAE group, the survival rate was significantly increased, the escape latency was shortened, the time of staying at the original platform quadrant was prolonged, and the number of crossing the original platform region was increased, the expression of BNIP3L in the hippocampal mitochondria was up-regulated, the MMP and content of mitochondrial ATP were increased ( P<0.05), the intensity of fluorescence of BNIP3L in the hippocampus was decreased, and the damage to mitochondrial ultrastructure was attenuated in SC group. Conclusions:BNIP3L-mediated mitochondrial dysfunction may be involved in the mechanism of SAE developed in mice.

Mathematical models for bulk erosion type drug delivery systems / 中国组织工程研究

Bulk erosion type biodegradable materials play an important role in pharmaceutics.However,the instability of carriers affects drug delivery systems critically,and complicates their drug release kinetics.Among these problems,how degradation and erosion affect drug release patterns becomes a focus.Mathematical models facilitate to understand complex pharmaceutical drug release patterns,and are easily applied in structure design of drug delivery systems and to predict their drug release kinetics.This paper reviews the degradation and erosion patterns,drug release mechanisms,and the recent research of mathematical models.

Preparation and in-vitro degradation of polylactide and poly(L-lactide-co-glycolide) / 生物医学工程学杂志

In this paper, DL-lactide, L-lactide and glycolide were synthesized from DL-lactic acid, L-lactic acid and glycolic acid respectively. A set of homopolymerizations of lactide with stannous octoate as initiator and laurly alcohol as co-initiator was carried out; a series of copolymers of poly (L-lactide-co-glycolide) (PLGA) were prepared via ring-opening polymerization of DL-lactide or L-lactide and glycolide with stannous octoate in high vacuum. The structure and properties of homopolymers and copolymers were characterized by 1H-NMR spectroscopy, differential scanning calorimetry and gel permeation chromatography. The in vitro degradation behavior of polylactide (PLA) and PLGA films in Hank's solution was investigated. The hydrolytic degradation of the PLA and PLGA was monitored by measuring the changes of inherent viscosity and weight loss of the resulting samples. The degradation rate of PLGA could be adjusted by changing the composition of the copolymer and be enhanced with the glycolide content increasing. It is suggested that the PLGA copolymer is a potential material as drug elusion coating on coronary stents.

Progress in researches of biodegradable intravascular stents / 生物医学工程学杂志

Biodegradable intravascular stents (BIS) become degraded after the short-term need for a stent and thus avoid the potential long-term complications of metal stents. In this paper, the research progress of BIS was reviewed; the materials, fabrication, design, experimental and clinical tests of biodegradable polymeric intravascular stents (BPIS) are introduced.

Monte Carlo simulation of poly(lactic-glycolic acid) films degradated in simulated body fluid / 中国组织工程研究

BACKGROUND: Poly(lactic-co-glycolic acid) (PLGA) has been widely used as medical implants and drug vehicle. Due to various factors involved in the degradation process, it is rather difficult to simulate the mass loss properties of PLGA.OBJECTIVE: To investigate the mass loss properties of PLGA films, and observe the correlation between the stimulation and the factual measurement.DESIGN: Repeated measuring experiment. SETTING: School of Materials Science and Engineering, Dalian University of Technology.MATERIALS: PLGA 50:50, 70:30 and 75:25 with weight average molecular weight (Mw) of 63 000, 115 000 and 400 000 were purchased from Shandong Key Laboratory of Medical Polymer Materials, and 1,4-dioxane (analytically pure) was purchased from Tianjin No.1 Chemical Reagent Factory and used as solvent.METHODS: The experiments were carried out in the School of Materials Science and Engineering of Dalian University of Technology from April to July in 2006.①PLGA were dissolved in 1, 4-dioxane according to the mass ratio of 50:50, 70:30 and 75:25, and the solution were cast into 10 mm×10 mm×1 mm polymer films.②PLGA films were immersed in Hank's simulated body fluid (Ph 7.4) at 37 ℃, and then taken out every week (every 5 days for PLGA 50:50). The samples were washed and dried to measure the changes of number and Mw using gel permeation chromatography. Degradation velocity was also worked out. Meanwhile the mass loss properties of PLGA films were measured using electronic balance. Furthermore, an improved Monte Carlo method was applied to carry out the correlation analysis with experiment data. MAIN OUTCOME MEASURES: ①degradation rates of PLGA with different ratios of lactic acid and glycolic acid.②the correlation coefficient between simulation results and experiment data.RESULTS: ①The degradation rates for PLGA at 50:50, 70:30 and 75:25 were 0.058 5, 0.016 6 and 0.010 1 /d (based on Mn), or 0.061 0, 0.017 5 and 0.008 5 /d (based on Mw), respectively.②Correlation coefficients between simulation results and experiment data for PLGA 50:50, 70:30 and 75:25 were 0.973 6, 0.987 4 and 0.990 3 correspondingly. CONCLUSION:The numerical simulation results for the mass loss properties of PLGA fit the experiment data well.

Quality standards of Kangxian Pills / 中成药

AIM: To establish the methods of quality control of Kangxian Pills (Redix Astragali,Radix Angelicale Sinensis,Rhizoma Chuanxiong,Radix Scutellariae,Fructus Schisandrae Chinensis,etc.). METHODS: Radix Angelicae sinensis;Rhizoma Chuanxiong;Radix Astragali;Radix Scutellariae were identified with TLC and the content of deoxyschizandrin and schisandrin B in the Kangxian Pills were determined by HPLC The separation was performed on Diamonsil~(TM) C_(18)(4.6 mm?250 mm,5 ?m)analytical column with a mobile phase consisted of methanol and water(78(∶)22) at the flow rate of 1.0 mL/min.The UV detection wavelength was set at 254 nm first and was altered to 220 nm after 17 min. RESULTS: The same color spots in the TLC graphs of sample existed at the corresponding position compared with the reference solution.The linear range of deoxyschizandrin was within 0.39-(1.95) ?g(r=0.999 9).The average recovery was 98.8%,RSD was 1.7%.The linear range of schisandrin B was within 0.09-0.45 ?g(r=0.999 9).The average recorery was 99.1%,RSD was 1.7%. CONCLUSION: The methods are simple and have good reproducibility.