ABSTRACT
Objective To optimize the preparation technology of transcription activator (TAT) and polyethylene glycols (PEG) co-modified tilianin-loaded composite phospholipid liposome (TAT & PEG tilianin CPL, T&PTCPL) and investigate its protective effect on cardiomyocytes. Methods The composite phospholipid liposome was prepared by thin film-ultrasonic method. A three- factor, three-level Box-Behnken experimental design was employed. The weight ratio of total phospholipid to tilianin (X1), the concentration of DSPE-PEG2000-TAT (X2), and hydration volume (X3) were observed. The encapsulation efficiency (Y1), particle size (Y2), and polydispersion coefficient (Y3) were evaluated to optimize optimal formula. In addition, hypoxia/reoxygenation model was established with Na2S2O4 in H9C2 cells. Superoxide dismutase (SOD) activity, malonaldehyde (MDA) level and release of lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) were assessed to evaluate the effect of T&PTCPL, meanwhile, the in vitro release rate (dynamic dialysis method) and absorption rate of tilianin and T&PTCPL in Caco-2 cell were examined. Results The optimal formula was as following: X1 = 20, X2 = 1.7%, and X3 = 3.2 mL; The encapsulation efficiency was (86.62 ± 2.51)%, particle size was (149.7 ± 8.2) nm and PDI was 0.15 ± 0.05. Compared with model group, T&PTCPL and tilianin groups increased SOD activity, inhibited level of MDA, LDH and CK-MB leakage (P < 0.05), and the effect of T&PTCPL group was better than tilianin group, meanwhile, T&PTCPL was completely released at 48 h, with a cumulative release of 88.65%, and Caco-2 cells had better absorption of T&PTCPL. Conclusion The Box-Behnken design is suitable for optimizing the formulation of T&PTCPL, and the observed responses are in close agreement with the predicted values of the mathematic models; Moreover, T&PTCPL shows a better sustained release effect in vitro release, which promots the absorption of tilianin in Caco-2 cells and suggests that T&PTCPL may have protective effect on myocardial ischemia reperfusion injury.
ABSTRACT
Objective: To optimize the preparation of Saussureae Involucratae Herba extract (SIHE)-composite phospholipid liposome (CPL) by the central composite design-response surface methodology (CCD-RSM) and to investigate the in vitro release of drugs. Methods: The method of ammonium sulfate transmembrane gradients was adopted to prepare SIHE-CPL. The single factor experiments were used for the key experimental factors and their test ranges. Based on the single factor experiments, with the size of SIHE-CPL, polymey disperse index (PDI), encapsulation efficiency (EE), and Zeta potential as dependent variables, central composite design was adopted to optimize the preparation technology by taking the content of phospholipid and the content of cholesterol as independent variables, test results were fitted by multiple linear and binomial nonlinear equations, and optimum formulation was selected by RSM, then the in vitro release behavior of the drug was studied by method of dynamic dialysis. Infrared (IR) spectroscopy and X-ray diffraction (XRD) pattern were used to analyze the spectroscopic properties of SIHE-CPL. Results: The second-order polynomial equation was superior to the linear one, the observed values agreed well with model predicted values. The optimal process conditions were as follows: Size of SIHE-CPL was (102.7 ± 5.1) nm, PDI was 0.154 ± 0.017, EE of chologenic acid and rutin was (87.68 ± 2.57)% and (84.18 ± 2.97)%, Zeta potential was (-28.4 ± 2.2) mV, SIHE-CPL and solution of SIHE were both accorded with the first order model, and IR analysis and XRD proved the formation of SIHE-CPL. Conclusion: The size and PDI of SIHE-CPL are low, the EE and Zeta potential of SIHE-CPL are high. CCD-RSM could be successfully used to optimize the prescription of SIHE-CPL.