HPLC assay and pharmacokinetics and tissue distribution study of glycyrrhetinic acid liposomes modified with galactosylated lipid

Dynamic monitoring of bacteriostatic process by SERS analysis based on a simple but effective detection strategy

Investigating antibacterial process at a molecular level is helpful to fully understand the mechanism of bacteriostasis and develop new antimicrobial agents. Herein, a simple but effective sensor strategy of antibacterial nanocomposite combined with surface-enhanced Raman scattering (SERS) substrate was applied for the robust detection of bacteriostatic process. The synergistic SERS effect of nanocomposite and Ag nanoparticles (NPs) substrate was confirmed by finite difference time domain (FDTD) solutions. A curcumin liposome@Au NPs nanocomposite was designed and prepared as a kind of bacteriostatic agent and SERS material as well. By means of electrostatic attraction between the nanocomposite and bacteria (methicillin resistant staphylococcus aureus, MRSA), specific detection of MRSA and monitoring of the molecular structure changes after bacteriostaticeffect were realized by SERS. Important intermediates produced in the bacteriostatic process were also measured at the same time. The relationship between the relative peak intensities and the structure of MRSA were thus established. The results were verified by high performance liquid chromatography-mass spectrometry (HPLC-MS), reactive oxygen species (ROS) kit, and flow cytometry. The detection strategy we proposed could not only be used for real-time detection of bacteriostatic processes with a high efficiency, but also a powerful tool for analyzing the mechanism in biochemical processes.

Nano-Traditional Chinese Medicine: a promising strategy and its recent advances

Traditional Chinese medicine(TCM) has been applied to the prevention and treatment of numerous diseases and has an irreplaceable role of rehabilitation and health care. However, the application of TCM is...

Antibody-modified liposomes for tumor-targeting delivery of timosaponin AIII

Introduction

Timosaponin AIII (TAIII), as a steroid saponin in Anemarrhena asphodeloides, has favorable potential as an antitumor candidate. However, its hydrophobicity and low bioavailability severely limit its in vivo antitumor efficacy.

Methods

To overcome this drawback, TAIII-loaded liposomes (LP) were prepared to improve TAIII solubility and extend its circulation time. Furthermore, anti-CD44 antibody-modified LP (CD44-LP) was prepared to enhance the therapeutic index of TAIII. The LP and CD44-LP were also characterized through their biological activity, target selective binding and uptake, and in vivo pharmacokinetics.

Results

Compared with free TAIII, both LP and CD44-LP possessed a desirable sustained-release profile in vitro, with ~14.2- and 10.7-fold longer TAIII half-life, respectively, and 1.7- and 1.9-fold larger area under the curve, respectively. LP and CD44-LP enhanced TAIII antitumor activity against HepG2 cells and in a xenograft mouse model without detectable toxicity. In particular, CD44-LP exhibited notably higher cytotoxicity than did LP, with a lower half-maximal inhibitory concentration (48 h). CD44-LP exhibited stronger tumor inhibition, and the tumor inhibitory effect was 1.3-fold that of LP. Furthermore, confocal laser scanning microscopy and in vivo near-infrared imaging of a xenograft mouse model revealed that compared with LP, CD44-LP could effectively enhance tumor accumulation.

Conclusion

Taken together, the results indicate that both CD44-LP and LP can considerably extend TAIII circulation time, increase tumor-targeted accumulation, and enhance antitumor activity. Thus, the anti-CD44 antibody-modified liposome is a promising candidate for treating CD44-positive cancer with considerable antitumor effects.

Modifying glycyrrhetinic acid liposomes with liver-targeting ligand of galactosylated derivative: preparation and evaluations

In this study, novel glycyrrhetinic acid (GA) liposomes modified with a liver-targeting galactosylated derivative ligand (Gal) were prepared using a film-dispersion method. To characterize the samples, particle size, zeta potential, drug loading, and encapsulation efficiency were performed. Moreover, plasma and tissues were pre-treated by liquid-liquid extraction and analyzed by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results showed that the mean residence times (MRTs) and the area under the curve (AUC) of GA liposomes with Gal (Gal-GA-LP), and GA liposomes (GA-LP) were higher than the GA solution (GA-S) in plasma. The tissue (liver) distribution of Gal-GA-LP was significantly different in contrast to GA-LP. The relative intake rate (Re) of Gal-GA-LP and GA-LP in the liver was 4.752 and 2.196, respectively. The peak concentration ratio (Ce) of Gal-GA-LP and GA-LP in the liver was 2.796 and 1.083, respectively. The targeting efficiency (Te) of Gal-GA-LP and GA-LP in the liver was 48.193% and 34.718%, respectively. Taken together, the results indicate that Gal-GA-LP is an ideal complex for liver-targeting, and has great potential application in the clinical treatment of hepatic diseases. Drug loading and releasing experiments also indicated that most liposomes are spherical structures and have good dispersity under physiologic conditions, which could prolong GA release efficiency in vitro.

Nanocarriers for the delivery of active ingredients and fractions extracted from natural products used in traditional Chinese medicine (TCM)

Traditional Chinese medicine (TCM) has been practiced for thousands of years with a recent increase in popularity. Despite promising biological activities of active ingredients and fractions from TCM, their poor solubility, poor stability, short biological half-life, ease of metabolism and rapid elimination hinder their clinical application. Therefore, overcoming these problems to improve the therapeutic efficacy of TCM preparations is a major focus of pharmaceutical sciences. Recently, nanocarriers have drawn increasing attention for their excellent and efficient delivery of active TCM ingredients or fractions. This review discusses problems in the delivery of active TCM ingredients or fractions; focuses on recent advances in nanocarriers that represent potential solutions to these problems, including lipid-based nanoparticles and polymeric, inorganic, and hybrid nanocarriers; and discusses unanswered questions in the field and criteria for the development of better nanocarriers for the delivery of active TCM ingredients or fractions to be focused on in future studies.