Study On Iayer-by-layer Polyelectrolyte Thin Film/Capsule For Drug Delivery

Since Decher made breakthrough of layer-by-layer (LbL) assembly technique,this simplicity, low cost, mildness technique had been greatly developed in twentyyears. LbL is a powerful tool to coat substrates of any size or shape, and canincorporate many different active compounds. Nowadays more and more attentionhad been paid to this drug delivery system.In this study, Layer by Layer (LbL) technique was used for sequential adsorptionof oppositely charged polymer poly (allylamine hydrochloride)(PAH), positivecharged polyurethane (PU), negative charged polyurethane (PU) through electrostaticinteraction. Methylene orange (MO), methylene blue (MB) and other dye were usedas model drugs to evaluate the potential ability of those multilayer film used in drugdelivery system. The main results were listed below.(1) Preparaed the poly (allylamine hydrochloride)(PAH)/polyrethane (PU)multilayer film, and investigate its drug loading and release capacity. Experimentalresults showed the ability of loading and release of MO from the film wassignificantly influenced by pH, salt concentration and the number of assemble layer.(2) Preparaed the polyurethane (PU)/hyaluronate (HA) Multilayer film, andinvestigate its drug loading and release capacity. Experimental results not only showthe ability of loading and release of MB from the film was significantly influenced bypH, salt concentration and the number of assemble layer, but also the solution’s chargecan be ruin the multilayer film. So this multilayer (PU/HA) film could be a promisingdrug delivery system with multi-sensitive because of its biocompatibility,biodegradation and above properties.(3) Preparaed Polyurethane (PU)/hyaluronate (HA) capsule by layer-by-layertechnique. TEM, SEM, Fluorescent were used to minitor the exist of (PU/HA)4capsule. Experimental results showed this capsule have very fine pH sensitive, thecapsule has better loading and released rate when it placed in imitate gastric juice.