Development of SLA 3D printed drug eluting medical implants for local cancer treatment

The current dogma of drug formulation technology places heavy focus upon the use of systemic oral or intravenous routes, for the delivery of a medicine to a target tissue. An inherent problem with this approach is the requirement of a high dosing regimen to ensure that the drug reaches the site of interest for optimal therapeutic effect. However, this can lead to the prevalence of ‘off-target’ effects and poor compliance. In the case of cancer, the ‘off-target’ effects of cytotoxic chemotherapeutics can cause greater harm than benefit to the patient. The aim of this project is to develop a medical implant that obviates the requirement of systemic dosing by providing a method of local drug release to the target area. Through utilisation of SLA 3D printing, we aim to develop and produce a drug eluting device that provides unidirectional release of patient-specific payloads at pre-determined pharmacokinetic rates. However, before a specific focus could be placed on cancer, three major problems associated with SLA 3D printing pharmaceutics had to be solved. Firstly, SLA 3D printed materials have unsuitable physical properties for medical device applications. Secondly, photopolymer systems based on (meth)acrylate photopolymer systems are associate with toxicity and hence have limited use as pharmaceutics. Finally, commercial SLA 3D printers do not support the use of custom photopolymer systems. Solving each of these problems would provide solid groundwork for the development of SLA 3D printed drug eluting implants for local chemotherapy. To solve the issue of poor mechanical properties, a range of current and novel photopolymers were synthesised, characterised and compared against one another and reference materials. To solve the issue of material toxicity, different post-processing procedures were explored and utilised in attempt to render SLA 3D printed materials as biocompatible. Finally, an RT-FTIR spectroscopy tool was developed to bridge the gap between unprintable and printable photopolymer systems. Furthermore, extensive drug release studies were conducted with aim to characterise effect of different SLA 3D printed materials on drug release kinetics