Open Collections

Engineering design of nanofibre wound dressings

University of British Columbia

This research aimed to develop a nanofibrous carrier design process for hydrophilic, small-molecule drugs for controlled wound healing. Kynurenine was used as representative example, as it presented challenges with its size and structure necessitating significant optimization to reach release target. The objective of the design is thus to facilitate controlled healing via addressing hypotheses on carrier material compatibility, release control through process or material modification, and fabrication of continuous structures. The design process began with material selection, which identified poly(vinyl alcohol) (PVA) as the candidate carrier. Experimental verification via drug-polymer interaction characterization suggested that kynurenine formed a solution with PVA, and was encapsulated within PVA nanofibres, implying drug release is diffusion-controlled. The characterization process provided more insightful understanding of drug release mechanism compared to data fitting to empirical models performed in existing literatures. Release assays showed complete kynurenine release from PVA within five hours. In subsequent optimization studies, three methods to control release from nanofibres were proposed. First, material parameters such as molecular weight, electrospinning concentration and drug dosage were shown to be a suitable fine-control mechanism. The second method was matrix modification via heat treatment, which changed the burst release behavior, although drug entrapment was observed. The third method was a composite approach in which the drug-polymer system was encased in the more hydrophobic poly(lactic-co-glycolic acid) (PLGA), which significantly reduced burst release, and extended the release period to over 120 hours. Applicability of the PVA kynurenine carrier, planar dressings and braided sutures were explored, which could become useful for a variety of wounds. For planar dressings, the proposed design showed tensile properties within the range of various commercial dressing products and thus was considered robust for handling and application to open acute and chronic wounds. For sutures, process modification in 3D braiding was introduced to significantly increase tensile strength, which could help create robust wound closure devices for patients prone to scarring. The outcomes of this study demonstrated customization of drug release and structural properties of wound dressing materials to suit various open wounds, to provide a platform for supporting the expanding therapeutic functionalities in next generation wound dressings.

Text

2014-12-17

Attribution-NonCommercial-NoDerivs 2.5 Canada

http://hdl.handle.net/2429/51553

Materials Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/2.5/ca/