Exploring the possible targeting strategies of liposomes against methicillin-resistant Staphylococcus aureus (MRSA).

Multi antibiotic-resistant bacterial infections are on the rise due to the overuse of antibiotics. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the pathogens listed under the category of serious threats where vancomycin remains the mainstay treatment despite the availability of various antibacterial agents. Recently, decreased susceptibility to vancomycin from clinical isolates of MRSA has been reported and has drawn worldwide attention as it is often difficult to overcome and leads to increased medical costs, mortality, and longer hospital stays. Development of antibiotic delivery systems is often necessary to improve bioavailability and biodistribution, in order to reduce antibiotic resistance and increase the lifespan of antibiotics. Liposome entrapment has been used as a method to allow higher drug dosing apart from reducing toxicity associated with drugs. The surface of the liposomes can also be designed and enhanced with drug-release properties, active targeting, and stealth effects to prevent recognition by the mononuclear phagocyte system, thus enhancing its circulation time. The present review aimed to highlight the possible targeting strategies of liposomes against MRSA bacteremia systemically while investigating the magnitude of this effect on the minimum inhibitory concentration level.

[Apoptosis of hepatocellular induced by active ingredients of Zanthoxyli Radix by Raman spectroscopy].

The apoptosis of mono-hepatocellular induced by the active ingredients of the Zanthoxyli Radix was investigated using laser Raman spectroscopy. Hepatoma cells (BEL-7404) were treated with 10 mg•L⁻¹ nitidine chloride and 3 g•L⁻¹ the extracts of Zanthoxyli Radix, respectively, then were divided into two parts, one for fluorescence staining, the other for determination of Raman spectroscopy. The acquired spectra were then processed by background elimination, smoothing, and normalization. Fluorescence staining results showed that the nucleuses from untreated group were uniformly stained, while those from the group treated for 48 hours were densely stained and broken. The spectra results revealed that the intensity of peaks associated with nucleic acid and protein decreased after the cells were incubated with the extracts of Zanthoxyli Radix for 12, 24, 36 and 48 hours. The intensity of peaks at 785,1 002,1 175,1 660 cm⁻¹ was decreased with the time of the cells were incubated by the extracts of Zanthoxyli Radix. The results indicated that the extracts of Zanthoxyli Radix could induce the apoptosis of hepatoma cells and reduce the amount of nucleic acid and protein in the cells. There is a certain relevance between the drug treatment time and the efficacy. The above results suggest that Raman spectra can provide abundant information about the changes in biological macromolecules within the cells after incubated by the extracts of Zanthoxyli Radix and serve as an effective method for the real time measurement of apoptosis.