Preparation and characterization of baicalin PEG-PLGA nanomicelles and tissue distribution in rats with acute myocardial ischemia / 中草药

ABSTRACT

Objective To prepare baicalin-polyethylene glycol-poly (lactic-co-glycolic acid) copolymer (PEG-PLGA)-loaded nanomicelles, and study its in vitro drug release properties and tissue distributed in rats with acute myocardial ischemia. Methods The preparation process of baicalin PEG-PLGA nanomicelles was optimized by orthogonal test. The optimized baicalin PEG-PLGA nanomicelles were characterized by particle size, Zeta potential, and TEM electron microscopy. The in vitro release assay and tissue distribution of the acute myocardial ischemia rat model were used to evaluate this drug delivery system. Results The preferred preparation conditions for baicalin PEG-PLGA nanomicelles were a mass ratio of baicalin to PEG-PLGA at 110 with a rotary evaporator rotation rate of 80 r/min and a hydration temperature of 40 ℃. The optimized baicalin PEG-PLGA nanomicelle particle size was (18.5 ± 0.5) nm, the zeta potential was (-10.9 ± 0.7) mV, the drug loading was (7.9 ± 0.3)%, and the encapsulation efficiency was (86.2 ± 2.5)%. The critical micelle concentration of PEG-PLGA nanomicelles was 3.8 μg/mL by oxime assay. TEM showed that baicalin PEG-PLGA nanomicelles presented a spherical shape with uniform particle size, In vitro release test showed that baicalin PEG-PLGA nanomicelles had obvious sustained release characteristics; Tissue distribution test showed that the order of distribution of baicalin PEG-PLGA nanomicelles in normal rat organs was liver > spleen > heart > kidney > lung > brain, while the distribution of baicalin PEG-PLGA nanomicelles in acute myocardial ischemia model was liver > heart > spleen > kidney > brain. Compared with normal rats, the drug concentration in the heart of rats with acute myocardial ischemia showed a significant increase trend in all time periods, and the highest drug concentration at 120 min could reach (2 897 ± 135) ng/mL, the highest drug concentration of the heart in the normal rats was (2 411 ± 89) ng/mL, which indicated that the baicalin PEG-PLGA nanomicelles had good targeting in the acute myocardial ischemia zone. Conclusion Baicalin PEG-PLGA nanomicelles have good drug-loading properties, slow release in vitro, and can accumulate drugs in the ischemic myocardium, which has good cardiac targeting.