Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0519030 (Klebsiella)
 21,988 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

PCL-based shape memory polyurethane ionomers with quaternarized pyridine moieties incorporated through molecular extension were synthesized. These polyurethanes were specifically designed as low-temperature thermoplastic anti-bacterial orthotic materials. A commercialized orthotic material was employed for comparison. The influence of ionic groups on the properties of orthotic materials was studied. The anti-bacterial properties and cytotoxicity of the polyurethane ionomer were tested. It was found that, different from other researchers' conclusions, the Coulombic force among cationic groups and the increased cohesion among hard segments after ionization could lead to polyurethane with better phase separation, soft segment phase crystallability and hard segment phase stability. The results of this work indicated that, although the ionic group had the function of improving phase separation, the asymmetric extender had a negative effect on the hard segment phase stability. Several of the main physical properties of the synthesized polyurethane as orthortic materials were studied. The materials mechanical properties at using temperature (ambient temperature 22 degrees C) were improved so it may be used in circumstances where high mechanical strength is required. The fixity ratio was increased; as a result the material may fix shape more precisely according to patient affected parts. At last, a prototype wrist orthotic device was fabricated by hands. The orthotic device percent reductions against Klebsiella pneumoniae and Staphylococcus aureus were 96.2% and 100%, respectively. The anti-bacterial activity rating of this device was acceptable and significant according to ASTM E 2149. Cytotoxicity tests indicated that the wrist orthotic material was not cytotoxic.
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PMID:A low-temperature thermoplastic anti-bacterial medical orthotic material made of shape memory polyurethane ionomer: influence of ionic group. 1915 70

Biofilms of multidrug-resistant bacteria in chronic wounds pose a great challenge in wound care. Herein, we report the topical delivery of molecularly engineered antimicrobial peptides using electrospun nanofiber dressings as a carrier for the treatment of biofilms of multidrug-resistant bacteria in diabetic wounds. Molecularly engineered human cathelicidin peptide 17BIPHE2 was successfully encapsulated in the core of pluronic F127/17BIPHE2-PCL core-shell nanofibers. The in vitro release profiles of 17BIPHE2 showed an in initial burst followed by a sustained release over 4 weeks. The peptide nanofiber formulations effectively killed methicillin-resistant Staphylococcus aureus (MRSA) USA300. Similarly, the 17BIPHE2 peptide containing nanofibers could also effectively kill other bacteria including Klebsiella pneumoniae (104 to 106 CFU) and Acinetobacter baumannii (104 to 107 CFU) clinical strains in vitro without showing evident cytotoxicity to skin cells and monocytes. Importantly, 17BIPHE2-containing nanofiber dressings without debridement caused five-magnitude decreases of the MRSA USA300 CFU in a biofilm-containing chronic wound model based on type II diabetic mice. In combination with debridement, 17BIPHE2-containing nanofiber dressings could completely eliminate the biofilms, providing one possible solution to chronic wound treatment. Taken together, the biodegradable nanofiber-based wound dressings developed in this study can be utilized to effectively deliver molecularly engineered peptides to treat biofilm-containing chronic wounds.
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PMID:Nanofiber Dressings Topically Delivering Molecularly Engineered Human Cathelicidin Peptides for the Treatment of Biofilms in Chronic Wounds. 3091 73