RESUMO
Photo-sensitive reactive oxygen species (ROS) responsive liposomes loaded with 1,4,8,11,15, 18,22,25-octabutoxypalladium phthalocyanine[PdPC(OBu)8] and doxorubicin hydrochloride (DOX) (LPD) were prepared by (NH4)2SO4-gradient method. LPD was characterized with transmission electron microscopy (TEM), dynamic light scattering particle size, zeta potentials, photo-sensitive ROS-responsive DOX release behaviors and the serum stability in vitro. LPD cytotoxicity, DOX uptake and singlet oxygen production in MCF-7 cells were evaluated. The results showed that the particle size of LPD was (169.3 ±1.2) nm, PDI of LPD was 0.198 ±0.003 and zeta potentials of LPD was (-39.8 ±0.8) mV. The accumulated release of DOX reached 95.5% in 5 min under 730 nm laser irradiation (300 mW·cm-2). The DOX uptake of liposome was increased and 1O2 was generated. The half inhibition concentration (IC50) of DOX in LPD with irradiation group was decreased by 85.7% and no irradiation group was decreased by 67.9% compared with free DOX group in MCF-7 cells. Therefore, photo-sensitive ROS-responsive liposomes would be a promising drug delivery system for tumor therapy.
RESUMO
Excessive reactive oxygen species (ROS) is associated with an array of pathological conditions, including cancer, diabetes, cardiovascular diseases, and neurodegenerative diseases. However, ROS-responsive materials have drawn attention in the development of drug delivery systems. There are many types of ROS-responsive materials explored in drug delivery applications, including sulfur-based responsive polymers, selenium-based responsive polymers, tellurium-based responsive polymers, oxalate ester-containing polymers, phenylboronic ester-containing polymers and unsaturated lipids. When integrated with ROS-responsive drug delivery systems, a photosensitizer is used as a light-sensitive element to generate ROS, mainly singlet oxygen (1O2), which in turn activates the ROS-triggered drug delivery.
RESUMO
<p><b>OBJECTIVE</b>To study eleven organophosphorus insecticides residuals in four kinds of Chinese crude drugs.</p><p><b>METHOD</b>The organophosphorus insecticides were extracted with dichloromethane and cleaned-up with a mixture of Celite 545-activated carbon. The extracts were analyzed by gas chromatography equipped with a flame photometric detector (FPD).</p><p><b>RESULT</b>Analysis of fortified Chinese crude drug showed that the average recoveries ranged from 77.5% -112.3% at three different levels, the RSDs were below 10% (n = 4). Trace organophosphorous pesticide residues were found in samples of Rhizoma Atractylodis Macrocephalae and Flos Chrysanthemi.</p><p><b>CONCLUSION</b>A method was established for determination multi-residues in Rhizma Atractylodis Macrocephalae, Radix Curcumae, Bulbus Fritillariae Thunbergii and Flos Chrysanthemi. It provides a method for the risk assessment of organophosphorous pesticide in Chinese crude drugs.</p>