Subject(s)
Conjunctiva/metabolism , Drug Delivery Systems/methods , Drug Implants/administration & dosage , Hydrogels/administration & dosage , Animals , Atropine/administration & dosage , Atropine/adverse effects , Atropine/pharmacokinetics , Dogs , Drug Delivery Systems/adverse effects , Drug Delivery Systems/instrumentation , Drug Implants/adverse effects , Drug Implants/pharmacokinetics , Fluoroquinolones/administration & dosage , Fluoroquinolones/adverse effects , Fluoroquinolones/pharmacokinetics , Humans , Hydrogels/chemistry , Methacrylates/administration & dosage , Methacrylates/adverse effects , Methacrylates/chemistry , Ophthalmic Solutions/administration & dosage , Ophthalmic Solutions/adverse effects , Ophthalmic Solutions/pharmacokinetics , Pyrrolidinones/administration & dosage , Pyrrolidinones/adverse effects , Pyrrolidinones/chemistry , Tears/metabolismABSTRACT
A new procedure was developed for the controlled application of adherent hydrophilic and biocompatible coatings onto the surface of "endless" metallic wires. Use of copolymers of 1-vinyl-2-pyrrolidinone and alkylmethacrylates provided coatings with excellent adherence and lubricity, and markedly low thrombogenicity. Coated wires could be spiralized without damaging the coating; the resulting coils are potentially useful as lubricious guidewires for use in, for example, interventional cardiology or urology. This study demonstrates that the lubricity of the coating is dependent on the composition (hydrophilicity) of the coating biomaterial, as well as on the thickness of the coating. Furthermore, the results imply that the adherence of the hydrophilic coating is essentially due to entanglement of the binder polymer chains and the hydrophilic copolymer chains. Moreover, the idea to use the hydrophilic coating on the wire as a temporary depot for controlled local drug delivery was explored. The coating was loaded with the dye rhodamine, and release of the dye upon immersion of the coated wire in water was studied. This work revealed that release of the drug is dependent on the composition of the coating. The potential utility of such wires with a drug-charged coating for controlled local drug delivery is discussed briefly.
Subject(s)
Coated Materials, Biocompatible/toxicity , Metals/toxicity , Polymers/toxicity , Blood/drug effects , Delayed-Action Preparations , Fluorescent Dyes , Humans , Lubrication , Magnetic Resonance Spectroscopy , Metals/blood , Rhodamines , Thrombosis/chemically inducedABSTRACT
The rotavirus genome codes for two glycoproteins: an outer capsid structural glycoprotein (VP7, apparent molecular weight 38,000 (38K)) and a nonstructural glycoprotein (NS28K). The synthesis of these glycoproteins was analyzed in infected cells and in a cell-free system derived from rabbit reticulocyte lysates supplemented with dog pancreatic microsomes. The data showed a 37K product synthesized in the cell-free system is the precursor to the 38K glycoprotein and that the 37K polypeptide contains a cleavable signal sequence (apparent molecular weight 1.5K). The 37K polypeptide was glycosylated in vitro in the presence of microsomal membranes to a polypeptide of 38K that was immunoprecipitated by monospecific antiserum to VP7. Endo H digestion of the 38K polypeptides from either infected cells or the cell-free system produced polypeptides of identical molecular weight, 35.5K (the glycoprotein precursor lacking the signal sequence). These results were confirmed by comparative studies with a variant of SA11 that is defective in glycosylation of VP7. Similar experiments with the 20K precursor to the 29K nonstructural glycoprotein showed the 20K polypeptide contains a noncleavable signal sequence. Both glycoproteins were inserted into microsomal membranes and were processed via oligosaccharide trimming.
