Carboxymethyl-hexanoyl Chitosan Nanodroplets for Ultrasonic Imaging and Drug Delivery to Tumor.

INTRODUCTION: Although a great many strategies have been proposed for tumor-targeted chemotherapy, current delivery methods of anticancer drugs present limited success with inevitable systemic toxicity. The aim of this study was to develop a new kind of theranostic carrier for targeted tumor therapy. METHODS: Prior to prepare CHC-PFP-DOX, carboxymethyl-hexanoyl chitosan (CHC) was synthesized by acylation of carboxymethyl chitosan. To develop CHC-PFP, perfluoropentane (PFP), an ultrasound gas precursor, was simultaneously encapsulated into the hydrophobic inner cores of pre-formulated CHC micelle in aqueous phase via using the oil in water (O/W) emulsion method. The size distribution and surface charges of these nanodroplets were measured and the morphology was observed by transmission electron microscopy (TEM). For ultrasound imaging application, in vitro model was established to evaluate the imaging of CHC-PFP-DOX under different concentration and mechanical index. After that, the anti-tumor effect of ultrasound combined with CHC-PFPDOX on ovarian cancer cells was investigated. RESULTS: The resulting CHC-PFP-DOX had a nano-sized particle structure, with hydrophobic anticancer DOX/PFP inner cores and a hydrophilic carboxymethyl chitosan polymer outer shell. The favorable nano-scaled size offers the potential to extravagate from veins and accumulate in tumor tissues via enhanced permeation and retention (EPR) effect. Additionally, CHC-PFP-DOX showed the ability to serve as ultrasound imaging agent at body temperature. Notably, it exhibited an ultrasound-triggered drug release profile through the external ultrasound irradiation. Further study demonstrated that ultrasound combined with CHC-PFP-DOX can improve the killing effect of chemotherapy for tumor. CONCLUSION: CHC-PFP-DOX holds great promise in simultaneous cancer-targeting ultrasound imaging and ultrasound- mediated delivery for cancer chemotherapy.

Diagnostic efficacy of lung ultrasound and X-ray for neonatal respiratory distress syndrome and transient tachypnea / 中国医学影像技术

Objective To compare the efficacy of lung ultrasound and chest X-ray for diagnosis of neonatal transient respiration syndrome (TTN) and respiratory distress syndrome (RDS).Methods Totally 120 infants with respiratory distress underwent lung ultrasound and chest X-ray within 6 h after birth.Taking clinical diagnosis as the standard,the sensitivity,specificity and accuracy of lung ultrasound and X-ray for diagnosis of TTN and RDS were calculated.Results According to clinical diagnosis,there were 75 infants of TTN and 34 of RDS.The sensitivity,specificity and accuracy of lung ultrasound in diagnosis of TTN was 96.00％ (72/75),88.89％ (40/45) and 93.33％ (112/120),respectively,higher than those of chest X-ray (85.33％ [64/75],84.44％ [38/45] and 85.00％ [102/120]).Lung ultrasound showed 85.29％ (29/34) of sensitivity,95.35％ (82/86) of specificity and 92.50％ (111/120) of accuracy for diagnosis of RDS,whereas chest X-ray showed 88.23％ (30/34) of sensitivity,89.53％ (77/86) of specificity and 89.17％ (107/120) of accuracy.Conclusion Lung ultrasound is accurate for the diagnosis of TTN and RDS.

Inhibitory effect of ultrasound-mediated drug loaded carboxymethyl hexanoyl chitosan nanodroplet on ovarian cancer cells / 中国医学影像技术

Objective To evaluate the inhibitory effect of phase change doxorubicin loaded carboxymethyl hexanoyl chitosan nanodroplet on ovarian cancer cells,and the effect of its ultrasound image in vitro.Methods The carboxymethyl hexanoyl chitosan synthesized through the acylationreaction with carboxymethyl chitosan and hexanoic anhydride.The drug loaded carboxymethyl hexanoyl chitosan nanodroplets were prepared by ultrasonic emulsification.The surface morphology,particle diameter and electric potential were characterized.Ultrasound imaging of the nanodroplet was evaluated in vitro.The encapsulation efficiency was determined by ultraviolet spectrophotometry.The survival rate of ovarian cancer cell was detected using CCK-8 reagent.The statistical analysis was performed.Results The drug loaded carboxymethyl hexanoyl chitosan nanodroplet was successfully prepared which showed regular morphology in microscope,the mean diameter of (458.33± 43.50)nm.The encapsulation efficiency was (52.06 ± 10.14)％.The nanodroplet could enhance ultrasonic imaging.The survival rate of ultrasound combined with drug loaded nanodroplet group ([62.54± 3.60]％) was lower than those of the free drug group ([75.55±7.21]％) and drug loaded nanodroplet group ([76.18±4.94]％),ultrasound group ([89.90±0.83]％;P＜0.05).Conclusion Ultrasound-mediated drug loaded nanodroplet can inhibit ovarian cancer cells,and has the potential for application in the clinical diagnosis and treatment.

Protective effects of sodium ferulate in vascular endothelial function during cardiopulmonary bypass / 中华胸心血管外科杂志

ObjectiveCardiopulmonary bypass (CPB) and its related ischemia reperfusion injury may cause endothelial cell injury.To study the protective effects of sodium ferulate in vascular endothelial function during CPB by testing the changes of vascular endothelial cell( CEC),nitric oxide( NO) and endothelin-1 ( ET-1 ) in children with congenital heart disease.MethodsSixty patients with congenital heart disease,including 28 males and 32 females were studied.The mean age was (19.7 ±10.4) months and body weight (10.5 ±6.1) kg.There were 37 VSD,8 ASD,7 TOF,5 TAPVC and 3 CAVC,among them 26 patients had pulmonary hypertension.They were randomly divided in to two groups:sodium ferulate group ( group S,n = 30),and control group ( group C,n =30) .Sodium ferulate (8 mg/kg) was given intravenously before CPB.Blood samples were taken from the arterial line at following time points:before CPB (TO),bypass 30 min(Tl ),the termination of CPB (T2 ),2h after operation ( T3 ) and 6h after operation ( T4 ),respectively for determination the concentration of vascular endothelial cell (CEC) in the blood,the concentration of nitric oxide (NO) and endothelin-1 ( ET-1) in the plasma.ResultsThere were no significant difference for the two groups regarding above parameters at TO ( P > 0.05).The level of CEC was significantly elevated after CPB in both groups ( P < 0.05 ) .CEC were lower at T2 in group S than in group C ( P < 0.05 ) .NO was decreased in both groups,but was higher in group S at T2,T3 and T4 ( P < 0.05 ) .The concentration of plasma ET-1 was not significantly different before CPB,but there was a slight decrease at T1,and then it was significantly increased in both groups (P<0.05).But it was lower in group S than in group C at T1,T2,T3 and T4(P<0.05 orP<0.01).ConclusionThere was severe endothelial cell damage during CPB.Sodium Ferulate can effectively antagonize the secretion of ET-1 to promote the formation of NO.Therefore,it reduces CPB-induced endothelial cell damage and protects vascular endothelial function during CPB.