orabase and Infections

Bioresponsive polymers (BRPs) allow the detection of potentially pathogenic microorganisms. Here, peptidoglycan and cellulose based hydrogels were constructed with potential for diagnosis of wound infection or, for example, Aspergillosis, respectively. These systems respond to extracellular enzymes from microbes or enzymes secreted from the human immune system in case of infection. Laccases as 'enhanzymes' were incorporated into these devices for signal and stability enhancement when compared to simple dye release based systems. To retain the enhanzymes within the BRPs, they were either PEGylated laccase (Laccase_PEG) to increase size or methacrylated laccase (Laccase_MA) to allow covalent attachment to the polysaccharide matrices. PEGylation of Trametes hirsuta laccase led to a fivefold increase in size to 270kDa according to size exclusion chromatography (SEC). Likewise, successful methacrylation of the laccase was demonstrated by using reversed phase chromatography while SEC analysis proved covalent attachment of the enzyme to the methacrylated polysaccharide matrix. Upon incubation of peptidoglycan based BRPs with fluid from infected wounds, the difference to controls was four times higher for Laccase_PEG based signalling when compared to simple dye release. Similarly, the control signals (i.e. leaching) were considerably reduced in case of Laccase_MA incorporated in crosslinked peptidoglycan (PG) and carboxymethylcellulose (CMC) hydrogels for signalling. In addition, Laccase_MA catalysed colour formation enhanced the signal dramatically with factors between 100- and 600-fold. Laccase_MA was demonstrated to oxidise silica gel immobilised ferulic acid incorporated into the BRP with clearly visible colour changes of 4.5 ΔE units according the CIELab concept upon incubation by trigger enzymes as well as infected wound fluids.

Topics: Biosensing Techniques; Carboxymethylcellulose Sodium; Coumaric Acids; Humans; Hydrogels; Infections; Laccase; Methacrylates; Peptidoglycan; Polyethylene Glycols; Polysaccharides; Substrate Specificity

Three weeks after a mild and presumably infectious illness, a 21-year-old man developed a CNS disorder characterized by involvement of the cerebellum, cerebrum, and brainstem. It progressed, sometimes stepwise, without remission, over five months to being bedfast with total spastic paraplegia, severe ataxia, and unintelligible dysarthric speech. The CSF showed increased levels of protein, IgG, and myelin basic protein, as well as five oligoclonal bands. Because of failure of the patient's condition to respond to prolonged prednisone therapy, poly ICLC was given intravenously weekly for 20 weeks (median dose, 100 microgram/kg). Improvement, evident after the first dose, progressed to the point of ambulation with some assistance. Even though the relation of the patient's marked recovery to poly ICLC therapy remains unproved, this experience provides reason for considering a possible therapeutic role of the drug in postinfectious demyelinating encephalomyelitis and perhaps in multiple sclerosis.

Topics: Adult; Carboxymethylcellulose Sodium; Demyelinating Diseases; Encephalomyelitis; Humans; Infections; Male; Methylcellulose; Peptides; Poly I-C; Polylysine