Nanofibres in Drug Delivery

Abstract

for their feedback on drafts of the chapters. Professor Mohan Edirisinghe and Professor Kevin Taylor are also thanked for their insightful comments on the manuscript.This book was prepared while CJL was funded by the Engineering and Physical Sciences Council (grant number EP/ P022677/ 1), and we gratefully acknowledge their support of her work. We further thank University College London and King's College London for their support for this endeavour in terms of time, infrastructure and resources.GRW would like to express thanks to Professor Chris Branford-White, Professor Limin Zhu and Professor Deng-Guang Yu for introducing him to the joys of electrospinning way back in 2010.Finally, we thank the editorial team at UCL Press for their great efforts in making this book happen, with special thanks to Dr Chris Penfold for being so patient as the deadlines slipped by. Contents List of figures x List of abbreviations xxviiConTenTs viii vi i i 3.7 pH-controlled delivery 3.8 Pulsatile release 3.9 Multilayer materials 3.10 Thermoresponsive systems 3.11 Emulsion and suspension electrospinning 3.12 Tissue-engineering applications 3.13 Using fibres as sacrificial templates 3.14 Conclusions 3.15 References LisT of fiGuRes xiixi i the jet volume and V 2 is the space the jet is not occupying in the conical frustum. 2.4 The concept of entanglement. (a) Small molecules and low-molecular-weight polymers cannot effectively overlap and entangle. Instead, they flow easily past one another. This leads to low-viscosity solutions which suffer from Rayleigh instability. (b) High-molecular-weight polymers undergo effective entanglement, meaning the force of elongation outweighs the surface tension and permitting electrospinning to be performed. 2.5 A digital photograph depicting bending instabilities during an electrospinning experiment. (Modified with permission from Yu, D. G.; Yu, J. H.; Chen, L.; Williams, G. R.; Wang, X. 'Modified coaxial electrospinning for the preparation of high-quality ketoprofen-loaded cellulose acetate nanofibers.' Carbohydr. Polym. 90 (2012): 1016-1023, with permission from Elsevier. Copyright Elsevier 2012.) 2.6 Defects that may arise during fibre solidification, showing (a) smooth, cylindrical fibres resulting from a welloptimised process; (b) flattened fibres; (c) wrinkled fibres; and (d) merged fibres. (Images (a) and (b) are modified with permission from Yu, D. G.; Yu, J. H.; Chen, L.; Williams, G. R.; Wang, X. 'Modified coaxial electrospinning for the preparation of high-quality ketoprofen-loaded cellulose acetate nanofibers.' Carbohydr. Polym. 90 (2012): 1016-1023, with permission from Elsevier. Copyright Elsevier 2012. Images (c) and (d) are modified with permission from Jia, D.; Gao, Y.; Williams, G. R. 'Core/ shell poly(ethylene oxide)/ Eudragit fibers for sitespecific release.' Int. J. Pharm. 523 (2017): 376-385, with permission from Elsevier.Copyright Elsevier 2017.) 2.7 The effect of solution viscosity on the products from electrohydrodynamic processing. 2.8 Spinneret designs for different types of...

Engineering of Nanofibrous Amorphous and Crystalline Solid Dispersions for Oral Drug Delivery

“…Mono-axial electrospinning is the simplest and as a result of this the most common electrospinning experiment. The polymer (and API) in solution or suspension is dispensed through a single-bore blunt-end needle resulting in a monolithic product, with the API and polymer typically evenly and homogeneously blended throughout the fibers [58].…”

pH-Responsive nanocomposite fibres allowing MRI monitoring of drug release

“…20 It has been widely explored to produce materials for a variety of fields, including tissue engineering, biosensors, wound dressings, and drug delivery. [21][22][23] Only a few studies have probed the incorporation of SPIONs into electrospun fibres for biological applications, but there is clear promise: Huang et al reported polystyrene fibres with a high loading capacity of SPIONs, with the resultant formulation effective in killing cancer cells via magnetic hyperthermia. 24 In other work, Wang et al revealed that drug-loaded dehydroxypropyl methyl cellulose phthalate and cellulose acetate fibres encapsulating SPIONs demonstrated superparamagnetism at room temperature, indicating the feasibility of magnetic-field induced release.…”

Fabrication of Electrospun Levodopa-Carbidopa Fixed-Dose Combinations

“…Electrospinning first involves the preparation of a mixed solution of a polymer and drug in a volatile solvent, followed by ejection of this solution through a narrow-bore needle and the application of an electrical field to solidify the product. It is beneficial over other techniques such as spray drying and hot-melt extrusion because it does not require the application of heat, and thus thermally labile active ingredients can be processed [14]. Further, electrospinning allows multiple different fluids to be processed simultaneously, leading to fiber products with highly tunable properties [15,16].…”