Lipopeptide C17 Fengycin B Exhibits a Novel Antifungal Mechanism by Triggering Metacaspase-Dependent Apoptosis in Fusarium oxysporum.

Fusarium wilt is a worldwide soil-borne fungal disease caused by Fusarium oxysporum that causes serious damage to agricultural products. Therefore, preventing and treating fusarium wilt is of great significance. In this study, we purified ten single lipopeptide fengycin components from Bacillus subtilis FAJT-4 and found that C17 fengycin B inhibited the growth of F. oxysporum FJAT-31362. We observed early apoptosis hallmarks, including reactive oxygen species accumulation, mitochondrial dysfunction, and phosphatidylserine externalization in C17 fengycin B-treated F. oxysporum cells. Further data showed that C17 fengycin B induces cell apoptosis in a metacaspase-dependent manner. Importantly, we found that the expression of autophagy-related genes in the TOR signaling pathway was significantly upregulated; simultaneously, the accumulation of acidic autophagy vacuoles in F. oxysporum cell indicated that the autophagy pathway was activated during apoptosis induced by C17 fengycin B. Therefore, this study provides new insights into the antifungal mechanism of fengycin.

Antifungal activities of Bacillus velezensis FJAT-52631 and its lipopeptides against anthracnose pathogen Colletotrichum acutatum.

This study was aim at investigating antifungal activities of Bacillus velezensis FJAT-52631 and its lipopeptides against Colletotrichum acutatum ex situ and in situ. The results showed that the strain FJAT-52631 and its crude lipopeptides (10 mg/ml) exhibited strong inhibitory effects on growth of C. acutatum FJAT-30256 with an inhibition rate of 75.3% and an inhibition zone diameter of 17.66 mm, respectively. Both the viable bacterial cultures and lipopeptides of FJAT-52631 could delay the onset of loquat anthracnose by 1 day and lower the incidence of loquat anthracnose in situ. The whole cultures of B. velezensis FJAT-52631 displayed a 50% biocontrol efficacy on loquat anthracnose at the fourth day after inoculation, but the crude lipopeptides not. The average lesion diameter of the whole-culture treated group was 5.62 mm, which was smaller than that of control group (6.81 mm). All the three types of lipopeptides including iturin A, fengycin, and surfactin A secreted from the strain FJAT-52631 exhibited antifungal activities. Among them, surfactin A displayed higher antifungal activity at a concentration of 1.25 mg/mL than other two lipopeptides even if at a concentration of 60 mg/mL. Thus, the results indicated that surfactin A produced by FJAT-52631 played a major role in the biocontrol of the loquat anthracnose. Scanning electron microscopy (SEM) observation revealed the structural deformities in the mycelia of C. acutatum. The above results suggested that the antifungal lipopeptides from B. velezensis FJAT-52631 would be potential in biocontrol against anthracnose disease of loquat caused by C. acutatum.

Preparation of a liposomal delivery system and its in vitro release of rapamycin.

The aim of this study was to prepare a liposomal delivery system for rapamycin and study its in vitro release characteristics. The results may provide a foundation for the further development of a liposomal delivery system for rapamycin and the establishment of a new active treatment method targeted towards the cellular components of atherosclerotic plaques. The ethanol injection method was used to prepare rapamycin-containing liposomes. The formulation was optimized by orthogonal design, and the degree of rapamycin release by the liposomes was measured by the reverse dialysis method. Orthogonal testing showed that the optimum formulation had a phospholipid concentration of 4%, a phospholipid-cholesterol mass ratio of 8:1, a drug-lipid mass ratio of 1:20 and an aqueous phase pH of 7.4. Rapamycin-containing liposomes with an encapsulation efficiency of 82.11±2.13% were prepared, and the in vitro release of rapamycin from the liposomes complied with a first-order kinetic equation. In conclusion, the formulation was optimized, the prepared liposomes had a high rapamycin encapsulation rate and good reproducibility, and their in vitro release had a certain delayed-release effect.

Intrathecal injection of lentivirus-mediated glial cell line-derived neurotrophic factor RNA interference relieves bone cancer-induced pain in rats.

Bone cancer pain is a common symptom in cancer patients with bone metastases and the underlying mechanisms are largely unknown. The aim of this study is to explore the endogenous analgesic mechanisms to develop new therapeutic strategies for bone-cancer induced pain (BCIP) as a result of metastases. MRMT-1 tumor cells were injected into bilateral tibia of rats and X-rays showed that the area suffered from bone destruction, accompanied by an increase in osteoclast numbers. In addition, rats with bone cancer showed apparent mechanical and thermal hyperalgesia at day 28 after intratibial MRMT-1 inoculation. However, intrathecal injection of morphine or lentivirus-mediated glial cell line-derived neurotrophic factor RNAi (Lvs-siGDNF) significantly attenuated mechanical and thermal hyperalgesia, as shown by increases in paw withdrawal thresholds and tail-flick latencies, respectively. Furthermore, Lvs-siGDNF interference not only substantially downregulated GDNF protein levels, but also reduced substance P immunoreactivity and downregulated the ratio of pERK/ERK, where its activation is crucial for pain signaling, in the spinal dorsal horn of this model of bone-cancer induced pain. In this study, Lvs-siGDNF gene therapy appeared to be a beneficial method for the treatment of bone cancer pain. As the effect of Lvs-siGDNF to relieve pain was similar to morphine, but it is not a narcotic, the use of GDNF RNA interference may be considered as a new therapeutic strategy for the treatment of bone cancer pain in the future.

[Systematic reviews of mini-invasive surgery versus standard approaches for total knee arthroplasty].

OBJECTIVE: To conduct a systematic review to compare the early efficacies of minimally invasive surgery (MIS) versus conventional approaches in TKA (total knee arthroplasty). METHODS: Randomized controlled trials (RCTs) and clinical controlled trials (CCTs) were retrieved from the databases of MEDLINE (1996.6 - 2010.12), EMBASE (1996.6 - 2010.12), PubMed (1996 - 2010.12) and Cochrane Library (Issue 2, 2012). Journal of Orthopedics (from establishment to December 2010) and Orthopedic Journal of China (from establishment to December 2010) were manually searched. Both RCTs and CCTs were included. The data were extracted by two reviewers with designed extraction form RevMan 4.2.8 software for data analysis. The criteria were as follows: (1) operative duration and reduced blood loss; (2) VAS (visual analog scale) score; (3) faster recovery of ROM (range of movement); (4) quadriceps muscle strength; (5) component positioning malalignment; (6) tibiofemoral angle; (7) rate of complications. RESULTS: A total of 18 RCTs were included. Compared with the standard TKA procedure, the MIS group had a longer operative duration (WMD (weighted mean difference) 14.16, 95%CI (confidence interval) (12.61, 15.71)); reduced blood loss (WMD 8.31, 95%CI (6.16, 10.46)); lower VAS score at Days 3-5 post-operation (WMD 4.99, 95%CI (4.19, 5.78)); better Mean Knee Society scores at Week 6 post-operation (WMD 4.99, 95%CI (4.19, 5.78)), improvement in ROM occurred more rapidly at Month 3 post-TKA (WMD 14.59, 95%CI (8.39, 20.80)). Although the differences were not statistically significant, tibiofemoral angle was more precise in the standard group and the rate of component malalignment occurred more frequently in the MIS group (WMD 0.20, 95%CI (-0.12, 0.52)) (RR 1.57, 95%CI (0.88, 2.83)). CONCLUSION: MIS leads to a faster recovery than conventional surgery with a shorter operative duration, a reduced blood loss, a lower VAS score and a faster recovery of ROM and quadriceps muscle strength. However, the rates of component malalignment and complications occur more frequently in the MIS group. Potential benefits in long-term survival rate and functional improvement require further investigations.

Degradation kinetics of water-insoluble lauroyl-indapamide in aqueous solutions: prediction of the stabilities of the drug in liposomes.

The aim of this study was to explore the degradation kinetics of water-insoluble lauroyl-indapamide in solutions and predict the stabilities of lauroyl-indapamide encapsulated in liposomes. Buffer-acetone (9:1) was used as the reaction solution and the reaction temperature was maintained at 60 degrees C. The correlation of the apparent degradation constants (k(obs)) of lauroyl-indapamide in liposomes and in buffer-acetone solutions at different pH has been explored. The degradation of lauroyl-indapamide in solutions was found to follow pseudo-first-order kinetics and was significantly dependent on the pH values. Lauroyl-indapamide was the most stable at pH 6.8, increasing or decreasing the pH of the solutions would decrease its stabilities. Buffer concentration had some effects on the stabilities of lauroyl-indapamide. The degradation active energies Ea were 68.19 kJ x mol(-1), 131.75 kJ x mol(-1) and 107.72 kJ x mol(-1) at pH3.6, 6.8 and 12 respectively in acetone-free buffer solutions (0.05M) calculated according to the Arrhenius equation with the extrapolation method. The apparent degradation constants (kobs) of lauroyl-indapamide in liposome and in buffer-acetone (9:1) solutions showed a good correlation at different pH levels, which indicates that the stabilities of the drug that dissolved in acetone-buffer mixture solutions can be used to predict the stabilities of the drug in liposomes as well.

[Factors influencing the content of residual tert-butyl alcohol in cyclodextrin complex prepared by lyophilization cosolvent system].

In order to minimize the residual tert-butyl alcohol (TBA) level in cyclodextrin complex prepared by freeze drying TBA/water cosolvent system, the formulation and lyophilization procedure that may influence the residual TBA was studied. Residual TBA in freeze dried cyclodextrin complex was determined by gas chromatography. The significant formulation and processing factors that influence residual TBA were identified by adjusting the initial TBA concentration in cosolvent, selecting cyclodextrin type (beta-cyclodextrin or hydroxypropyl beta-cyclodextrin), changing sample volume in flasket, altering freezing mode (fast freezing or slow freezing) and modifying the duration of secondary drying. The results show that the amorphous cyclodextrin material (hydroxypropyl beta-cyclodextrin), initial low TBA concentration in cosolvent and fast freezing would lead to high TBA residue in cyclodextrin complex, annealing was effective in reducing the residual TBA. The duration of secondary drying had no distinct effect on residual TBA. It is concluded that in order to reduce residual TBA in cyclodextrin complex prepared by lyophilization monophase solution, the initial TBA concentration in cosolvent should be higher than the crystal formation concentration, the appropriate cyclodextrin type and freeze drying processing should be choosen.

[Determination of liposome/water partition coefficients of salmeterol and budesonide and study on their influencing factors].

AIM: The liposome/water partition coefficients of salmeterol and budesonide between aqueous phase and liposomes were determined and the factors that influence their partition coefficients were studied, the mechanism of interaction between the two drugs and phospholipid bilayer was elucidated. METHODS: The liposome/water partition coefficients of the two drugs were determined by equilibrium dialysis technique. The change of the partition coefficients of the two drugs along with liposome composition and medium was also studied. RESULTS: The partition coefficients of the two drugs decreased with the increase of cholesterol content and saturation of phospholipid used. The liposome/water partition coefficient of salmeterol increased with the increase of liposome surface negative charge, medium pH and ionic strength, while the liposome surface charge, medium pH and ionic strength had no distinct effect on the liposome/water partition coefficient of budesonide. CONCLUSION: The liposome/water partition coefficient of drug was affected by the type, saturation of phospholipid used in liposome preparation, the cholesterol content and surface charge of liposome, as well as the pH and ionic strength of medium also have effect on the liposome/water partition coefficient of drug. Accordingly, in order to reflect the actual partition of drug in biological membrane, the determination condition including liposome composition and medium should be similar to the biological membrane.

[Study on pharmacokinetics of PVP coated beta-elemene liposome in rats].

OBJECTIVE: To study the pharmacokinetics of PVP costed beta-elemente liposmes in rats. METHODS: Gas chromatography was established to determine the concentration of beta-elemene in plasma of rats after administered through i.g. RESULTS: The pharmacokinetics parameters was: T(1/2) = 95.07 +/- 20.46 min, AUC = 348.72 +/- 32.49 microg x min/ml, Cmax = 4.39 +/- 0.33 microg/ml, Tmax = 60 min. CONCLUSION: The bioavailability of PVP coated beta-elemene liposomes is 140.2 +/- 7.5% compared with conventional liposomes.

In-vitro cytotoxicity, in-vivo biodistribution and anti-tumour effect of PEGylated liposomal topotecan.

In attempt to increase the accumulation of topotecan in tumours and improve its anti-cancer activity, PEGylated liposome (H-PEG) containing topotecan was prepared. The in-vitro cytotoxicity, in-vivo biodistribution pattern and anti-tumour effect of H-PEG were studied systemically. Compared with free topotecan or conventional liposome (H-Lip), H-PEG improved the cytotoxic effect of topotecan against human ovarian carcinoma A2780 and human colon carcinoma HCT-8 cells. The IC50 value (concentration leading to 50% cell-killing) of H-PEG decreased 5 fold (P<0.01) and 9 fold (P<0.01) against A2780 and HCT-8 cells compared with H-Lip, respectively. The results of biodistribution studies in sarcoma S(180) tumour-bearing mice showed that liposomal encapsulation increased the concentration of total topotecan and the ratio of lactone form in plasma. H-PEG resulted in a 70-fold and 3.7-fold increase in AUC(0-->24 h) compared with free topotecan and H-Lip, respectively. Moreover, H-PEG increased the accumulation of topotecan in tumours and the relative tumour uptake ratio compared with free topotecan was 5.2, and higher than that of H-Lip. The anti-cancer effect studies in murine heptocarcinoma H(22) tumour-bearing mice showed that H-PEG improved the therapeutic efficiency of topotecan and decreased the toxicity of topotecan to a certain extent compared with H-Lip. These results indicated that PEG-modified liposome might be an efficient carrier of topotecan.

[Preparation of cardiomyocyte-targeting liposomes and their targeting ability in vitro].

AIM: To prepare the cardiomyocyte-targeting liposomes and investigate their cardiomyocyte targetability in vitro. METHODS: Liposomes modified with compound PAC were prepared (PAC-L); The uptake of PAC-L by cardiomyocytes was studied by incubating fluorescence labeled liposomes with cardiomyocytes in vitro and measuring the association of liposomes by a fluorescence spectrophotometer. RESULTS: A high affinity of PAC-L to the cardiomyocytes was observed, the amount of cell uptake of PAC-L by cardiomyocytes was higher than that by nonmyocyte (P < 0.001); The amount of cardiomyocyte uptake of PAC-L on the normoxia condition 2 h was 2.9-fold higher than that of plain-L, and the increase was 5.2-fold when hypoxia occured; The form of liposome uptake changed, the amount of cardiomyocyte uptake of Plain-L by internalization was only 11%, while that of PAC-L was 56%. CONCLUSION: It is indicated that PAC-L was a potential drug carrier for targeting to ischemic myocardium.

Liposomal encapsulation of lauroyl-indapamide in the presence of divalent or trivalent cations.

Divalent or trivalent cations such as Ca2+, Ba2+, Mg2+, Zn2+, Fe2+, Al3+ and Fe3+ can cause a significant increase in the entrapment efficiency of lauroyl-indapamide in liposomes, from about 5% to more than 90%, which suggests that the presence of these ions plays an important role in the encapsulation of lauroyl-indapamide.

In vitro and in vivo studies of different liposomes containing topotecan.

Liposome as a carrier of topotecan (TPT), a promising anticancer drug, has been reported in attempt to improve the stability and antitumor activity of TPT. However, the biodistribution pattern of TPT liposome in vivo and PEG-modified liposome containing TPT have not been studied systemically. In this paper, the in vitro stability and in vivo biodistribution behavior of several liposomes containing TPT with different lipid compositions and PEG-modification were studied. Compared with the 'fluid' liposome (S-Lip) composed of soybean phosphatidylcholine (SPC), the 'solid' liposome (H-Lip) composed of hydrogenated soybean phosphatidylcholine HSPC decreased the leaking efficiency of TPT from liposome and enhanced the stability of liposome in fetal bovine serum (FBS) or human blood plasma (HBP). The results of biodistribution studies in S180 tumor-bearing mice showed that liposomal encapsulation increased the concentrations of total TPT and the ratio of lactone form in plasma. Compared with free TPT, S-Lip and H-Lip resulted in 5- and 19-fold increase in the area under the curve (AUC(0-->infinity)), respectively. PEG-modified H-Lip (H-PEG) showed 3.7-fold increase in AUC(0-->infinity) compared with H-Lip, but there was no significant increase in t(1/2) and AUC(0-->infinity) for PEG-modified S-Lip (S-PEG) compared with S-Lip. Moreover, the liposomal encapsulation changed the biodistribution behavior, and H-Lip and H-PEG dramatically increased the accumulation of TPT in tumor, and the relative tumor uptake ratios were 3.4 and 4.3 compared with free drug, respectively. There was also a marked increase in the distribution of TPT in lung when the drug was encapsulated into H-Lip and H-PEG. Moreover, H-PEG decreased the accumulation of TPT in bone marrow compared with unmodified H-Lip. All these results indicated that the membrane fluidity of liposome has an important effect on in vitro stability and in vivo biodistribution pattern of liposomes containing TPT, and PEG-modified 'solid' liposome may be an efficient carrier of TPT.

Oil-based formulations for oral delivery of insulin.

Several oil-based solution formulations of insulin were prepared, in which insulin was solubilized in the form of anhydrous reverse micelles. The preparation process involved micellar dissolution of insulin followed by freeze drying, then reconstitution of lyophilized product with an oil phase. These formulations were stable at room temperature for up to 12 months. No significant changes in the appearance were observed and no degradation products of insulin were detected during the course of the stability study. The efficacy of these formulations was evaluated in-vivo using diabetic Wistar rat as an animal model and then a specific formulation was chosen for further study in non-diabetic New Zealand rabbits. It was found that the efficacy of insulin oil solution was dose dependent and insulin oil solution had the same efficacy as insulin emulsion with the same formulation composition. If ethylene-diaminetetraacetic acid (EDTA) was pre-delivered 40 min before the delivery of insulin oil solution, the hypoglycaemic effect of insulin oil solution was greatly enhanced, with an AUC (% glucose reduced) value increase from 28.5 +/- 14.7 to 167.1 +/- 72.3. The improvement of oral absorption induced by predelivery of EDTA might be attributed to enzyme inhibition, reduced gut mobility and the opening of paracellular routes.