ABSTRACT
ObjectiveTo compare the effects on left ventricular remodeling of bone marrow mononuclear cells transplantation one week and three months after acute myocardial infarction.MethodsAcute myocardial infarction models were successfully established in 15 swine,which were randomly divided into three groups:placebo group,early transplantation group and late trasplantation group.One week after model had been established,early transplantation group underwent bone marrow mononuclear cells transplantation,and then so did the late trasplantation group three months after acute myocardial infarction.B-ultrasound and single photon emission computed tomography (SPECT) examinations were performed to assess the left ventricular end diastolic dimension( LVd),left ventricular end diastolic volume(EDV) and left ventricular ejection fraction(EF) before and one week,three months,six months after acute myocardial infarction.ResultsThe LVd of late transplantation group [ (54.20:t:3.70) mm] was lower than placebo group [ (63.20 ±5.63)mm],but higher than early transplantation group [ (47.40 ± 1.14)mm].The EDV of late transplantation group [ ( 163.00 ±6.96)ml] was lower than placebo group [ (209.40 ± 18.69)ml],but higher than early transplantation group [ ( 135.40 ± 4.93 ) ml ].The EF of late transplantation group (0.25 ±0.02) was higher than placebo group (0.19 ±0.02),but lower than early transplantation group (0.37 ±0.02).ConclusionsBone marrow mononuclear cells transplantation can alleviate progressing ventricular remodeling,even it is performed three month after acute myocardial infarction,but its therapeutic effects are inferior to early transplantation's.
ABSTRACT
BACKGROUND:Chitosan and gelatin have good biocompatibility and biodegradable properties.More and more attentions have been given to the application of the composite membrane of chitosan/hydroxyapatite(HA)and gelatin/HA as the tissue scaffolds.OBJECTIVE:To prepare a biocompatible composite membrane of chitosan/HA/gelatin having nanometer multilayer HA,and to investigate whether such a membrane might be a candidate of the tissue scaffolds for the bond repair and regeneration,DESIGN:Controlled observation.SETTING:College of Chemistry and Environmental Engineering,Jianghan UniversityMATERIALS:The experiments were performed at the Laboratory of Fine Chemistry,College of Chemistry and Environmental Engineering,Jianghan University from February to August 2007.Chitosan (Yuhnan Ocean Biochemistry Co.,Ltd,Zhengjiang,China,Mw 13.44×104,93% degree of deacetylation),and gelation(provided by Shanghai Chemical Reagent Co.,Shanghai,China)were used in the present study.METHODS:The mixture chitosan/CaCl2 solution was casted on a glass plate to give the membrane of chitosan/CaCl2.Then,the membrane was soaked in KH2PO4 solution,0.1 mol/L NaOH solution,and 3 wt% gelatin aqueous solution,respectively.The resulted membrane was washed and dried to obtain the chtiosan/HA/gelatin composite membrane.The morphological observation of the composite membrane and HA crystal were carded on a scanning electron microscope.The mechanical properties of the composite membrane were measured using the universal testing machine.The tensile strength(σb)and the elongation at break (ε)were calculated.The thermal stability of composite membrane was determined using a WCT-2C thermobalance.MAIN OUTCOME MEASURES:The morphologies,the mechanical properties,and the thermal stability of the composite membrane and HA crystal were observed.RESULTS:The multilayer HA crystal with 400 nm thickness in the composite membrane was observed.The tensile strength(σb)and the elongation at break(ε)of the composite membrane were 3.83-10.25 MPa and 3.97%-10.14%,respectively.The decomposition temperature of HA-treated membrane was 310℃,which was higher than that of chitosan/gelatin membrane(305℃).CONCLUSION:The composite chitosan/HA/gelatin membrane was prepared by using chitosan/CaCl2,KH2PO4 and gelatin solutions.Such a biocompatible composite membrane with multilayer HA might be a promising tissue scaffold.