Production of polymeric magnetic micro and nano-particles is a rapidly emerging area in pharmaceutical and biomedical science. In this thesis, the capability of the electrohydrodynamic atomization (EHDA) process for preparing biodegradable polymeric magnetic particles with different sizes was explored. The EHDA processing method offers several advantages over conventional coprecipitation and emulsification techniques for the preparation of magnetic particles. Most significant are the process efficiency and preservation of the iron oxide nanoparticles and/or therapeutic agents functionality, as complex multistep processing involving harsh solvents, additives and elevated temperatures or pressure are avoided. The first part of the thesis describes a detailed investigation of how the size, morphology and shape of the particles generated can be controlled through the operating parameters; specifically the flow rate and applied voltage. The particle diameter was greatly influenced by flow rate and applied voltage. The mean size of the particles changed from1.6µ m to 17.8µm as the flow rate increased from 100µl/min-1 to 400µl/min-1. The research also focuses on the effects of these parameters on the jetting modes of the E H DA process, in particular the con-jet mode operation. Magnetic nanospheres were also produced using single needle processing with mean size of 56nm with a corresponding polydispersivity index of 16%. Nanospheres exhibited a high saturation magnetization at room temperature (67emu/g). Chlorotoxin, a scorpion venom was chosen as the therapeutic agent model because it is non-toxic, non-immunogenic along with other favourable characteristics such as small size high stability and most importantly only binds to tumour cells and not healthy cells. Scorpion venom loaded magnetic microspheres were produced using single needle processing, with a particle size of 2µm. This work demonstrates a powerful method of generating micro and nano magnetic polymeric particles, with control over the size of particles prepared.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:647322 |
| Date | January 2015 |
| Creators | Gun, S. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1468713/ |
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