Biofilm Disruption Utilizing α/β Chimeric Polypeptide Molecular Brushes

Gram-negative bacteria can cause serious infections and are well known problems in biomedical practices. Biofilms of gramnegative bacteria are notorious for their frequently encountered resistance toward antibiotics. We demonstrate that α/β chimeric polypeptide molecular brush (α/β CPMB) exerts potent activities against antibiotic-resistant gram-negative bacteria. MTT viability assay, bacterial colony counting, and live/dead staining all indicate that α/β CPMB not only inhibits biofilm formation of gram-negative Pseudomonas aeruginosa and Acinetobacter baumannii, but also effectively disrupts mature biofllms that are highly resistant to one of the most active antibiotics-colistin. The superior antibacterial performance of the α/β CPMB implies its potential topical applications in treating biofilms.

Bioanalysis and Pharmacokinetics of Eight Active Components from Huanglian Jiedu Decoction in Rat Plasma by LC-ESI-MS/MS Method

Objective To develop a sensitive and rapid liquid chromatography-electrospray ionization-tandem mass spectrometry （LC-ESI-MS/MS） method for the simultaneous determination of wogonin, coptisine, berberine, palmatine, jatrorrhizine, phellodendrine, magnoflorine, and wogonoside in rat plasma and to evaluate the pharmacokinetic characteristics of Huanglian Jiedu Decoction （HJD）. Methods LC separation was performed on an Acquity HSS T3 column （100 mm × 2.1 mm, 1.8 μm） using gradient elution with the mobile phase consisting of acetonitrile and 0.1% formic acid water. The detection was accomplished by using positive electrospray ionization in multiple-reaction monitoring mode. Plasma samples were pretreated by protein precipitation. Results The method showed a good linearity over a wide concentration range （r^2 〉 0.99）. The lower limits of quantification were 0.20 ng/mL for coptisine and phellodendrine, 0.48 ng/mL for berberine, 0.10 ng/mL for jatrorrhizine, 0.32 ng/mL for magnoflorine, 0.30 ng/mL for palmatine, and 4.80 ng/mL for wogonin and wogonoside, respectively. The intra- and inter-day precision of the analytes was less than 12.11%, while the accuracy was between -14.46% and 4.86%. The mean recovery of all the analytes ranged from 93.10% to 110.91%. Conclusion This validated method offers thee advantages of high sensitivity. It is successfully applied to evaluating the pharmacokinetic properties of HJD.

Facile Synthesis of High Molecular Weight Polypeptides via Fast and Moisture Insensitive Polymerization of a-Amino Acid N-Carboxyanhydrides

Polypeptides have been widely utilized in the fields of biomaterials and biomedicine.Ever since N-carboxyanhydride(NCA)was reported by Hermann Leuchs in 1906,ring-opening polymerization of NCAS has been extensively used to prepare polypeptides.Despite continuous innovations,it is still challenging to synthesize polypeptides in high molecular weight fficiently.To address this challenge,we developed KHMDS/NaHMDS initiated fast NCA polymerization that is also moisture tolerant,open-flask amenable and terminal tunable.This NCA polymerization was able to proceed in most common solvents and meet the solubility requirement of variable NCA monomers and corresponding polypeptides.KHMDS can initiate r benzy-L glutamate-N carboxyanhydride(BLG NCA)polymerization in a reaction rate 92 times faster than does hexylamine and 80 times faster than does triethylamine.This NCA polymerization also demonstrated easy and fast synthesis of gram-scale long chain polypeptides in an open flask.

Antimicrobial Properties and Application of Polysaccharides and Their Derivatives

With the quick emergence of antibiotic resistance and multi-drug resistant microbes,more and more attention has been paid to the development of new antimicrobial agents that have potential to take the challenge.Polysaccharides,as one of the major classes of biopolymers,were explored for their antimicrobial properties and applications,owing to their easy accessibility,biocompatibility and easy modification.Polysaccharides and their derivatives have variable demonstrations and applications as antimicrobial agents and antimicrobial biomaterials.A variety of polysaccharides,such as chitosan,dextran,hyaluronic acid,cellulose,other plant/animal-derived polysaccharides and their derivatives have been explored for antimicrobial applications.We expect that this review can summarize the important progress of this field and inspire new concepts,which will contribute to the development of novel antimicrobial agents in combating antibiotic resistance and drug-resistant antimicrobial infections.

Application of Connectivity Map Database to Research on Chinese Materia Medica

The connectivity map（CMAP） database is established initially to connect biology, chemistry, and clinical conditions, which helps to discover the connection of disease-gene-drug. The CMAP approach has been applied in the field of drug discovery and development, which is widely recognized. In recently years, CMAP analysis has been applied in the research on Chinese materia medica（CMM）. The study of CMM is facing a wide range of challenges, such as complicated ingredients, multiple targets, multiple pathways of action and complex functioning mechanism. The idea of employing CMAP in the CMM research has brought a new perspective for researchers and provides a systematic method for elucidating the mechanism of CMM.The connectivity map （CMAP） database is established initially to connect biology, chemistry, and clinical conditions, which helps to discover the connection of disease-gene-drug. The CMAP approach has been applied in the field of drug discovery and development, which is widely recognized. In recently years, CMAP analysis has been applied in the research on Chinese materia medica （CMM）. The study of CMM is facing a wide range of challenges, such as complicated ingredients, multiple targets, multiple pathways of action and complex functioning mechanism. The idea of employing CMAP in the CMM research has brought a new perspective for researchers and provides a systematic method for elucidating the mechanism of CMM.