[Analysis on preparation and characterization of asiaticoside-loaded flexible nanoliposomes].

Asiaticoside is a compound extracted from traditional Chinese medicine Centella asiatica, and mainly used in wound healing and scar repair in clinical, with notable efficacy. However, its poor transdermal absorption and short action time restrict its wide application. In this experiment, the reserve-phase-extrusion-lyophilization method was conducted to prepare the lyophilized asiaticoside-loaded flexible nanoliposomes (LAFL). Its characteristics including electron microscope structure, particle size, Zeta potential, entrapment rate, drug-loading rate, stability and drug release were determined with the intelligent transdermal absorption instrument. LAFL were white spheroids, with pH, particle size and zeta potential of 7. 03, 70. 14 nm and - 36. 5 mV, respectively. The average entrapment rate of the 3 batch samples were 31. 43% , and the average asiaticoside content in 1 mg lyophilized simple was 0. 134 mg. The results indicated that LAFL have good physicochemical properties and pharmaceutical characteristics, with an improved transdermal performance.

Nano-hydroxyapatite/ß-tricalcium phosphate ceramics scaffolds loaded with cationic liposomal ceftazidime: preparation, release characteristics in vitro and inhibition to Staphylococcus aureus biofilms.

In the current study, nano-hydroxyapatite/ß-tricalcium phosphate (HA/ß-TCP) ceramics scaffolds loaded with cationic liposomal ceftazidime (CLCs) prepared by modified reverse phase evaporation method, the investigations of their release characteristics were performed by the dissolution tests, in vitro anti-biofilm activity of the scaffolds was studied by the determination of bacterial susceptibility with ELISA. The mean particle size, zeta potential, pH and entrapment efficiency of the CLCs studied were 161.5 ± 5.37 nm, 60.60 ± 5.24 mV, 6.90 ± 0.07 and 16.57 ± 0.13%, respectively. Electron microscopic images of the samples indicated that the liposomes were well preserved in the scaffolds and that it was the CLCs rather than free ceftazidime releasing from the scaffolds. The minimal inhibitory concentrations (MICs) to Staphylococcus aureus of free ceftazidime and its liposomal formulation were 6.00 µg/mL and the release behaviors of both CLCs and free ceftazidime from scaffolds were based on the dissolution/diffusion processes, Fick's law. These results demonstrated that CLCs could inhibit remarkably the formation of S. aureus biofilm more effectively than free ceftazidime (P < 0.05). The study demonstrated that the HA/ß-TCP ceramic scaffolds was such a material that could sustain release CLCs and maintain the adequate amounts of CLCs to absorb to biofilm. It provided an ideal way to inhibit bacterial biofilms for clinical practices.

Nano-hydroxyapatite/chitosan/konjac glucomannan scaffolds loaded with cationic liposomal vancomycin: preparation, in vitro release and activity against Staphylococcus aureus biofilms.

The objective of this study was to design a novel artificial bone scaffold for the therapy and prevention of refractory bacterial infections. Porous nano-hydroxyapatite/chitosan/konjac glucomannan (n-HA/CS/KGM) scaffolds were loaded with cationic liposomal vancomycin (CLV) to form a novel complex drug carrier (LLS). The kinetics of CLV release from LLS and the effects of the amount of konjac glucomannan (KGM) and CLV in LLS were examined in vitro. The anti-biofilm activity of LLS was also studied. Electron microscopy indicated that the liposomes were well preserved in the scaffold, and that CLV rather than free vancomycin is released from the scaffold. The weight percentage of KGM or CLV greatly influenced the release behavior of the scaffolds. LLS could provide sustained CLV release and inhibited the formation of Staphylococcus aureus biofilms better than scaffolds without CLV loaded. LLS may be a novel, effective drug-delivery system for the antibiotic treatment of osteomyelitis caused by biofilm infections.