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Please use this identifier to cite or link to this item: https://dspace.lboro.ac.uk/2134/19339

Title: Structured biodegradable polymeric microparticles for drug delivery produced using flow focusing glass microfluidic devices
Authors: Ekanem, Ekanem E.
Nabavi, Seyed Ali
Vladisavljevic, Goran T.
Gu, Sai
Keywords: Microfluidic flow focusing
Biodegradable microspheres
Drug delivery systems
Poly(lactic acid)
Poly(lactic-co-glycolic acid)
Janus particle
Hemispherical particle
Issue Date: 2015
Publisher: © American Chemical Society
Citation: EKANEM, E.E. ...et al., 2015. Structured biodegradable polymeric microparticles for drug delivery produced using flow focusing glass microfluidic devices. ACS Applied Materials & Interfaces, 7(41), pp 23132–23143.
Abstract: Biodegradable poly(DL-lactic acid) (PLA) and poly(lactic-co-glycolic acid) (PLGA) microparticles with tunable size, shape, internal structure and surface morphology were produced by counter-current flow focusing in axisymmetric (3D) glass capillary devices. The dispersed phase was composed of 0.5-2 wt% polymer solution in a volatile 2 organic solvent (ethyl acetate or dichloromethane) and the continuous phase was 5 wt% aqueous poly(vinyl alcohol) solution. The droplets with a coefficient of variation in dripping regime below 2.5 % were evaporated to form polymeric particles with uniform sizes ranging between 4-30 μm. The particle microstructure and surface roughness were modified by adding nanofiller (montmorillonite nanoclay) or porogen (2-methylpentane) in the dispersed phase to form less porous polymer matrix or porous particles with golf-ball-like dimpled surface, respectively. The presence of 2-4 wt% nanoclay in the host polymer significantly reduced the release rate of paracetamol and prevented the early burst release, as a result of reduced polymer porosity and tortuous path for the diffusing drug molecules. Numerical modelling results using the volume of fluid-continuum surface force model agreed well with experimental behaviour and revealed trapping of nanoclay particles in the dispersed phase upstream of the orifice at low dispersed phase flow rates and for 4 wt% nanoclay content, due to vortex formation. Janus PLA/PCL (polycaprolactone) particles were produced by solvent evaporation-induced phase separation within organic phase droplets containing 3 % (v/v) PLA/PCL (30/70 or 70/30) mixture in dichloromethane. A strong preferential adsorption of Rhodamine 6G dye onto PLA was utilized to identify PLA portions of the Janus particles by Confocal Laser Scanning Microscopy (CLSM). Uniform hemispherical PCL particles were produced by dissolution of PLA domes with acetone.
Description: This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials & Interfaces, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acsami.5b06943
Version: Accepted for publication
DOI: 10.1021/acsami.5b06943
URI: https://dspace.lboro.ac.uk/2134/19339
Publisher Link: http://dx.doi.org/10.1021/acsami.5b06943
ISSN: 1944-8244
Appears in Collections:Published Articles (Chemical Engineering)

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