Controlled release by novel lysostaphin-loaded hydroxyapatite/chitosan composites / 药学学报

Lysostaphin is highly effective on eliminating methicillin resistant Staphylococcus aureus (MRSA). In order to achieve controlled release of lysostaphin, a biocompatible drug carrier is needed. Hydroxyapatite/chitosan (HA/CS) composites were chosen to carry lysostaphin and sample composites with different weight ratios of HA to CS, including 80/20, 70/30, 60/40, and 40/60, were prepared. Multiple analyses were performed to determine the structural and physicochemical properties of the composites, including scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. We immersed HA/CS composites loaded with 1 wt% lysostaphin to test in vitro release activity and cultured MC3T3-E1 cells to carry out biocompatibility test. The result of the release behavior of the composites revealed that the controlled release of lysostaphin from 60/40 HA/CS composites was the highest release rate of (87.4 ± 2.8)%, which lasted for 120 hours. In biocompatibility testing, MC3T3-E1 cells were able to proliferate on the surface of these composites, and the extract liquid from the composites could increase the growth of the cells. These results demonstrate the controlled release of lysostaphin from HA/CS composites and their biocompatibility, suggesting the potential application of these composites to bone injury and infection applications.

The Design and Construction of K11: A Novel α-Helical Antimicrobial Peptide.

Amphipathic α-helical antimicrobial peptides comprise a class of broad-spectrum agents that are used against pathogens. We designed a series of antimicrobial peptides, CP-P (KWKSFIKKLTSKFLHLAKKF) and its derivatives, and determined their minimum inhibitory concentrations (MICs) against Pseudomonas aeruginosa, their minimum hemolytic concentrations (MHCs) for human erythrocytes, and the Therapeutic Index (MHC/MIC ratio). We selected the derivative peptide K11, which had the highest therapeutic index (320) among the tested peptides, to determine the MICs against Gram-positive and Gram-negative bacteria and 22 clinical isolates including Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus epidermidis, and Klebsiella pneumonia. K11 exhibited low MICs (less than 10 µg/mL) and broad-spectrum antimicrobial activity, especially against clinically isolated drug-resistant pathogens. Therefore, these results indicate that K11 is a promising candidate antimicrobial peptide for further studies.

Detection of recombinant lysostaphin using antibody sandwish enzyme-linked immunoadsorbent assay / 生物工程学报

The double-antibody-sandwich enzyme-linked immunoadsorbent assay (ELISA) for detection of rLysostaphin in humans had been developed and established through this study. rLysostaphin of high purity ( > 95 % ) produced in Shanghai Hi-Tech United Bio-Technological Research & Development Co., Ltd (SHUBRD) was used to produce a rabbit anti-rLysostaphin polyclonal antibody. The standard curve of rLysostaphin polyclonal antibody that was constructed showed that the lowest range of detection was found at 0. 98 ng of rLysostaphin/mL, and the curve exhibited linearity preferably from 0. 98 to 500 ng of rLysostaphin/mL. When three serum samples of the same batch were assayed for 6 replicates, and more 3 samples from different batches for 6 replicates, the average intra-assay and inter-assay coefficient variances ( CV) were 6. 4% and 6. 5%, respectively. The relative recovery rate was 98.6% when quantitative standard antigens were added to the serum. The present method for detection of rLysostaphin in serum is specific, highly sensitive, highly precise, and exhibited a low CV and will be helpful in the further study of rLysostaphin pharmacokinetics and holds promise in clinical applications.

Effect of Tripterygium wilfordii polyglycoside on serum IL-2 and TNF-alpha in patients with acute anterior U-veitis / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the effect of Tripterygium wilfordii polyglycoside (TWP) on level of serum interleukin 2 (IL-2), and tumor necrosis factor alpha (TNF-alpha) in patients of acute anterior uveitis (AAU).</p><p><b>METHODS</b>Patients of AAU were randomly divided into two groups. The treated group (n = 50) was mainly treated with TWP and the control group (n = 50) treated with bimolani. The level of IL-2 and TNF-alpha before and after treatment were determined and compared between the two groups and also compared between the treated group and normal group consisted of 50 healthy subjects.</p><p><b>RESULTS</b>Levels of IL-2 and TNF-alpha in the treated group before treatment were 1.31 +/- 0.27 micrograms/L and 1.20 +/- 0.65 micrograms/L, and after treatment 1.19 +/- 0.27 micrograms/L and 0.96 +/- 0.54 microgram/L, those in the control group were 1.31 +/- 0.26 micrograms/L and 1.22 +/- 0.66 micrograms/L before treatment and 1.20 +/- 0.27 micrograms/L and 0.98 +/- 0.51 microgram/L after treatment respectively. Comparisons of the two parameters before and after treatment in both groups showed significant difference (P < 0.05 in TWP group and P < 0.01 in bimolani group). The two parameters in both treated groups were all higher than those in the normal group before treatment (P < 0.05), but showed insignificant difference after treatment (P > 0.05).</p><p><b>CONCLUSION</b>Abnormal changes of IL-2 and TNF-alpha exist in AAU patients, TWP could suppress both parameters markedly therefore has a reliable effect in treatment of AAU.</p>