3.Recombinant human bone morphogenetic protein 2/poIy(Iactic-co-gIycoIic acid) copoIymer microspheres with different particIe sizes:preparation and reIease performance in vivo and in vitro
Yu-Cheng BAO ; Yong WANG ; Wen-Long ZHANG ; Yi XIE ; Mei-Li YU
Chinese Journal of Tissue Engineering Research 2018;22(2):210-215
BACKGROUND: The technology of biodegradable materials covering growth factors can be used to make sustained-release microspheres, which provides the feasibility for the efficient utilization of growth factors. OBJECTIVE: To prepare nano/micron-sized spheres using recombinant human bone morphogenetic protein 2/poly(lactic-co-glycolic acid) (rhBMP-2/PLGA)copolymer and to compare their release behaviors by in vivo and in vitro release experiments. METHODS: The rhBMP-2/PLGA nano/micron-sized spheres were prepared by emulsion solvent evaporation method to control the rate of pulp mixing.(1)In vitro release experiment:Prepared nano/micron-sized spheres were dissolved in PBS for 70 days,and then ELISA method was used to detect the rhBMP-2 concentration in the supernatant at different time.(2)In vivo release experiment:Forty-four New Zealand rabbits were divided into two groups, and rhBMP-2/PLGA nano/micron-sized spheres were respectively implanted into trochanteric defects. The concentration of rhBMP-2 in the defect site was detected by ELISA within 70 days after implantation. RESULTS AND CONCLUSION:In vitro sustained release experiment:There was a sudden release of nanospheres in the former 3 days,and the cumulative release nearly reached 41%, followed by a steady and slow release, and then the cumulative release was up to approximately 83% at 70 days. The initial release of micron-sized spheres was less than that of nanospheres, and the cumulative release was about 20% within the former 3 days and reached to 70% at 70 days.In vivo sustained release test:There was a sudden release of the nanospheres,the cumulative release was nearly 35%, followed by a steady and slow release, and then the cumulative release was up to approximately 72% at 70 days. The initial release of micron-sized spheres was less than that of nanospheres, and the cumulative release was about 21% in the former 3 days and increased to about 63% at 70 days.In both in vivo and in vitro release experiments,the release duration of micron-sized spheres was longer than that of nanospheres in the former 3 days. To conclude, the release time of rhBMP-2/PLGA micron-sized spheres fulfills the need of bone growth cycle, therefore, rhBMP-2/PLGA micron-sized spheres are more favorable than rhBMP-2/PLGA nanospheres for bone defect repair in clinical practice.
4.Observation on the effect of vitamin C in alleviating peroxidative damage in gut of dogs during enteral fluid resuscitation of severe burn shock.
Sen HU ; Jin-wei CHE ; Ying DU ; Cheng-mei BAO
Chinese Journal of Burns 2009;25(6):451-453
OBJECTIVETo investigate the effect of vitamin C (VC) on alleviating peroxidative damage in gut of dogs during enteral fluid resuscitation of severe burn shock.
METHODSEighteen male Beagle dogs were subjected to 50% total body surface area (TBSA) full-thickness burn 24 hours after duodenostomy and cannulation of cervical artery and vein. The dogs were divided into no resuscitation (NR) group (no treatment after burn), enteral resuscitation (ER) group, and ER+VC group according to the random number table, with 6 dogs in each group. Dogs in ER and ER+VC groups were respectively infused with glucose-electrolyte solution (GES) and GES containing 250 mg/kg VC through duodenostomy tube 30 minutes after burn. The infusion rate and volume of GES were in accordance with Parkland formula. Venous blood of dogs was drawn before (0) and at 2, 4, 6, and 8 post burn hours (PBH) to determine the activity of diamine oxidase (DAO) in plasma. Dogs were sacrificed at PBH 8 to collect specimens of jejunum tissue for determining the content of malondialdehyde (MDA), and activity of myeloperoxidase (MPO), xanthine oxidase (XOD) and superoxide dismutase (SOD), and assessment of the water ratio of intestinal tissue by dry-wet weight method.
RESULTS50% TBSA burn injury resulted in significant elevation of DAO in every group. The activity of DAO in ER group was obviously higher than that in NR group at PBH 6 and 8 (P < 0.05), but DAO activity in ER+VC group was significantly lower than those in the other two groups after PBH 2 (P < 0.05 or P < 0.01). MDA content, MPO and XOD activity and the water ratio of intestinal tissue [(5.74 +/- 0.51) nmol/mg, (2.08 +/- 0.46) U/g, (58.4 +/- 3.8) U/mg, (81.5 +/- 1.8)%] in ER group at PBH 8 was respectively significantly higher than that in NR group [(5.43 +/- 0.25) nmol/mg, (1.55 +/- 0.21) U/g, (50.1 +/- 2.8) U/mg, (78.3 +/- 1.5)%, P < 0.05 or P < 0.01]. While the activity of SOD in ER group (72 +/- 12) U/mg was lower than that in NR group (97 +/- 20) U/mg. MDA content, MPO and XOD activity and water ratio of intestinal tissue in ER+VC group was respectively lower than that in ER group, with activity of SOD in the former group higher than that in the latter group (P < 0.01).
CONCLUSIONSVitamin C can alleviate peroxidative damage and tissue edema in gut induced by ischemia and reperfusion, and intestinal complications during oral rehydration during burn shock can be reduced.
Animals ; Ascorbic Acid ; therapeutic use ; Burns ; therapy ; Dogs ; Fluid Therapy ; adverse effects ; Intestine, Small ; metabolism ; Male ; Oxidative Stress ; Reactive Oxygen Species ; metabolism ; Reperfusion Injury ; etiology ; prevention & control ; Shock ; therapy
5.Distribution of systemic vascular resistance disorders and its related factors in Hebei province.
Xiao-mei ZHOU ; Bao-shen QI ; Cheng-li XU ; Shao-mei HAN ; Guang-jin ZHU
Acta Academiae Medicinae Sinicae 2006;28(2):249-252
OBJECTIVETo analyze the distribution features of systemic vascular resistance (SVR) disorder in healthy subjects in Hebei province.
METHODSSVR and systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), pulse pressure (PP), heart rate (HR), cardiac output (CO), cardiac index (CI), stroke volume (SV), stroke index (SI), left ventricular ejection time (LVET), left cardiac work (LCW) and cardiovascular function were determined with Bioz. com Cardio Dynamics. Total cholesterol (TC), triglyceride (TG) and influencing factor were tested by automated hematology analyzer in 999 healthy subjects living in Hebei province.
RESULTSSVR disorder gradually increased with the ageing in healthy subjects and the prevalences of SVR disorders was higher among females than among males (P < 0.001). SVR was positively correlated with SBP, DBP, MAP, PP, LVET, body mass index (BMI), TC, and TG, and was inversely associated with HR, CO, CI, SV, SI, LCW, and arterial compliance (AC). CO and MAP were independent influencing factors with SVR.
CONCLUSIONSVR disorder is associated with age, sex, and blood pressure in populations in Hebei province and may be a marker of vascular injury.
Adolescent ; Adult ; Age Factors ; Aged ; Blood Pressure ; Body Mass Index ; Cardiac Output ; Female ; Hemodynamics ; physiology ; Humans ; Male ; Middle Aged ; Risk Factors ; Sex Factors ; Vascular Capacitance ; Vascular Diseases ; physiopathology ; Vascular Resistance
6.Study on urine biomarkers in 1,3-butadiene exposed workers.
Xue-mei CHENG ; Yan-ni JIAO ; Jin-dong CHEN ; Bao-de SHAN ; Zhao-lin XIA
Chinese Journal of Industrial Hygiene and Occupational Diseases 2012;30(9):661-666
OBJECTIVETo discuss the urine biomarkers in 1,3-butadiene exposed workers, and to provide basement for establishing biological limit value.
METHODS44 BD exposed workers as exposure group and 25 BD non-exposed people as control group including 12 workers in boiler workshop in the same factory and 13 people in one public institute, we collected their in-end-of shift urine, then detected urine BD-derived mercapturic metabolites [3,4-dihydroxybutyl mercapturic acid (DHBMA),1- and 2-monohydroxy-3-butenyl mercapturic acid (MHBMA)] concentrations using UPLC-MS/MS method. Meanwhile, we detected air BD concentration with GC-FID in the workplace, and compared their relationship.
RESULTSlgDHBMA and lg (MHBMA + DHBMA) levels in exposed group (lgDHBMA: 2.51 ± 0.44) µg/L, lg [MHBMA + DHBMA: (2.68 ± 0.27) µg/L] were higher than which in control group (lgDHBMA: (2.20 ± 0.25) µg/L, lg(MHBMA + DHBMA: (2.49 ± 0.34) µg/L), and the differences were significant (P < 0.01). Urine DHBMA was obviously influenced by air BD concentrations (r = 0.539, P = 0.001). The equation of Multiple Regression Analysis was y = 2.417 + 0.520x (x represents air BD dose, and represents urinary DHBMA level). Adjusted R(2) of this model was 0.262. Urinary MHBMA was not affected by smoking, alcohol and years of works.
CONCLUSIONUrine metabolite DHBMA in BD-exposed workers might be major biological exposure indice.
Adult ; Biomarkers ; urine ; Butadienes ; Female ; Humans ; Male ; Middle Aged ; Occupational Exposure ; adverse effects ; Surveys and Questionnaires
7.Study on the Expression, Purification and Activity of Arginine Deiminase
Xi-Dong ZHANG ; Jie-Lei LI ; Hong-Yi ZHANG ; Hongyi ZHANG ; Xiao-Jun HE ; Xin-Bao XU ; Mei XIAO ; Cheng-Li LIU ; Hui ZHANG ; Gang ZHAO ;
China Biotechnology 2006;0(06):-
Objective: To develop a high efficient expression, purification system of recombinant arginine deiminase(ADI).Methods: cDNA fragment encoding for mycoplasma ADI was obtained by artificial synthesis and was cloned into prokaryotic expression vector(pBV220). The recombinant ADI was generated by the transformation of the recombinant vector into the host strain DH5?. Anion exchange and gel filtration chromatography was carried out for purification of the recombinant ADI. The biological activity of final product was detected by the assay of agrinine degradation in vitro. Results: A prokaryotic expression plasmid pBV220-ADI was generated successfully, and was identified by DNA sequencing; the recombinant protein was highly expressed in DH5?, the proportion of the recombinant protein is exceeded 35% of the whole protein. The inclusion bodies were solubilized with 6mol/L guanidine hydrochloride under reducing conditions in order to avoid incorrect disulfide-bond formation of the recombinant ADI molecules. Dilution and dialysis at lower degrees temperature were the optimum renaturation methods. After gel filtration, the purity and specific activity of rADI reached 95% and 80 IU/mg respectively. Conclusions: A set of protocols for high efficient rADI expression and purification has been established, which is simple, efficient and applicable.
8.Poly(lactic-co-glycolic acid)-cycloserine microsphere preparation and in vitro release properties
Yu-Cheng BAO ; Wen-Long ZHANG ; Yong WANG ; Mei-Li YU ; Xue-Chun YANG ; Jing SHEN
Chinese Journal of Tissue Engineering Research 2018;22(6):871-876
BACKGROUND:Cycloserine with low hepatotoxicity exhibits no cross-resistance with the existing anti-tuberculosis drugs,and has been commonly used for the treatment of drug-resistant tuberculosis.However,its oral administration or injection leads to a certain degree of neurotoxicity.OBJECTIVE:To prepare poly(lactic-co-glycolic acid) (PLGA)-cycloserine sustained-release microspheres which are expected to reduce the neurotoxicity and adverse reactions,and maintain the drug concentration in the bone tuberculosis region for a long time,and to observe the in vitro drug release of the microspheresMETHODS:Double emulsion solvent evaporation method was used to prepare PLGA-cycloserine microspheres that were bonded into sponge implant by Bletilla striata polysaccharide extract.Then,morphology,particle size,encapsulation efficiency and in vitro performance of the microspheres were observed.The drug loading,burst release,appearance and dispersion of the microspheres were observed at 0,1,2 months after the microspheres were placed in room temperature (25 ℃),high temperature (60 ℃) and high humidity (93%),respectively.RESULTS AND CONCLUSION:The PLGA-cycloserine microspheres that were round and spherical presented with the mean particle size of (143±38) μm,the drug loading of 38.38% and the encapsulation efficiency of 67.54%.No burst release occurred,and the cumulative release of drug within 50 days was 65.62% After being stored at room temperature,high temperature and high humidity for 1 and 2 months,the microspheres were intact in the appearance and morphology,and showed insignificant changes in drug loading and burst release.To conclude,the time of degradation and the release of drug accord with the biological requirements of bone restoration.
9.Effects of electroacupuncture on hepatic blood flow and lipid peroxidation in septic rats.
Xian SHI ; Li-Jian ZHANG ; Hui-Ying BAI ; Cheng-Mei BAO ; Sen HU ; Ling GUAN
Chinese Acupuncture & Moxibustion 2010;30(5):397-400
OBJECTIVETo investigate the protection effects of electroacupuncture on injury of lipid peroxidation induced by liver ischemia in septic rats.
METHODSForty-eight male SD rats were subjected to sepsis induced by cecal ligation and puncture (CLP), and were randomly divided into a Sham operation group (group A), a CLP model group (group B), a CLP model plus electroacupuncture at "Zusanli" (ST 36) group (group C), a CLP model plus electroacupuncture at the shame acupoint (group D), a vagotomy plus CLP model group (group E) and CLP model plus electroacupuncture group after vagotomy (group F), 8 rats in each group. CLP was performed in group E and group F after the abdominal vagotomy. Bilateral "Zusanli"(ST 36) points and the shame acupoint were electroacupunctured (2 mA, 2/100 Hz) for 1 hour in group C, group F and group D, respectively. The hepatic blood flow (HBF) was detected by a laser-Doppler flowmetry at 6 h after CLP. The plasma activity of alanine aminotransferase (ALT) was also determined and specimens of liver were harvested for evaluation of malondialdehyde (MDA), xanthine oxidase (XOD) and assessment of the rate of water content.
RESULTSThe blood flow of the liver was (56.97 +/- 11.95) U in group C which was significantly lower than (80.12 +/- 19.57) U in group A but higher than (42.61 +/- 10.97) U in group B, (44.53 +/- 9.23) U in group D, (30.05 +/- 4.46) U in group E and (30.46 +/- 6.38) U in group F (all P < 0.05) 6 h after CLP. Meanwhile, the levels of MDA, XOD, ALT and the rates of water content in liver in group C were all significantly higher than those in group A, but lower than those in the other four groups (all P < 0.05). The levels of MDA, XOD, ALT and the rates of water content in liver in group E and group F were all significantly higher than those in group D (all P < 0.05), while the blood flow of the liver lower than that in group D (P < 0.05), and with no significant differences in all above measurements between group E and group F (all P > 0. 05).
CONCLUSIONElectroacupuncture at "Zusanli" (ST 36) can promote hepatic blood flow, inhibit lipid peroxidation and alleviate hepatic edema and dysfunction in septic rats, which might be related with the completeness of cranial nerve.
Alanine Transaminase ; blood ; Animals ; Electroacupuncture ; Lipid Peroxidation ; Liver Circulation ; Male ; Rats ; Rats, Sprague-Dawley ; Sepsis ; physiopathology ; therapy ; Xanthine Oxidase ; metabolism
10.Detection of SEN virus (subtype D/H) infection in Shenzhen.
Ling OUYANG ; Cheng-hui HUANG ; Ru-guan CHEN ; Yong-mei LIU ; Jian-guo HUANG
Chinese Journal of Epidemiology 2003;24(9):806-809
OBJECTIVETo investigate the prevalence of newly identified single-chain DNA virus (SENV) infection in Shenzhen.
METHODSNested polymerase chain reaction (nPCR) was established using primers from ORF1 region of SENV genome. Six hundred and one sera samples from different populations were detected for SENV DNA (D and H subtype) by nPCR. Products of PCR were cloned into T-vector and sequenced.
RESULTSThe positive rates of SENV DNA in different populations were as followed: 27.8% in patients with hepatitis B, 22.2% in patients with hepatitis C, 26.9% in hemodialysis patients and 39.3% in IDUs. Among blood donors, the positive rates of SENV DNA were 28.1% in unqualified blood donors, 31.3% in blood donors with an elevated ALT levels and 15.1% in qualified blood donors. The infection rates of SENV in unqualified blood donors and blood donors with an elevated ALT levels were obviously higher than in qualified blood donors (chi(2) = 8.29, P < 0.01 and chi(2) = 6.03, P < 0.01). There was a 6.8% difference of nucleotide between SENV-D standard subtype and 6 isolates with 13.5% difference of nucleotide between SENV-H standard subtype and 4 isolates from Shenzhen.
CONCLUSIONResults suggested that SENV infection was common in high-risk groups in Shenzhen.
Base Sequence ; China ; epidemiology ; DNA Virus Infections ; diagnosis ; epidemiology ; DNA Viruses ; classification ; isolation & purification ; DNA, Viral ; analysis ; Humans ; Molecular Sequence Data ; Polymerase Chain Reaction ; Prevalence