Glaucoma is a chronic optic neuropathy that affects an estimated 70 million
people worldwide of which 7 million are blind. The only proven modifiable risk
factor is raised intra-ocular pressure (IOP) and treatment to reduce IOP can
be in the form of eye drops, laser or surgery. Scarring and the development of
fibrous encapsulation at the surgical site complicate glaucoma surgery.
Development of a drug delivery platform to modulate the wound healing
response may improve surgical outcomes. Potential materials include
hydrogels, three-dimensional cross-linked networks of water-soluble
polymers, as well as 3D printed resins that are an increasingly popular
approach for rapid prototyping and manufacture.
The aim of this thesis was to assess the in vitro biocompatibility of 3D
printed and phosphorylcholine (PC) based materials compared to materials
used in current ophthalmic devices including polytetrafluoroethylene (PTFE),
polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), silicone,
2-hydroxyethyl methacrylate (HEMA). Sterility testing was performed using
ethanol and autoclaving processes. Adhesion of monocytes, macrophages
and fibroblasts to material surfaces was assessed using various assays and
fluorescent microscopy. Adsorption of albumin and fibrinogen was assessed
using SDS Page gel electrophoresis, UV photospectrometry, fluorescein
isothiocyanate labelled bovine serum albumin (FITC-BSA) and micro
bicinchoninic acid (BCA) techniques.
It was observed that PC based materials demonstrated less cellular and
protein adhesion than materials used in current ophthalmic devices but more
than a contact lens of similar composition suggesting that the manufacturing
process may play a role in the biocompatibility response. Similar levels of cell
adhesion and protein adsorption were observed between 3D printed materials
and materials used in current ophthalmic devices, but cytotoxicity is a
potential concern and further testing is warranted.
Our results demonstrate that PC hydrogels and 3D printed materials can
potentially be used in drug delivery devices to treat ophthalmic conditions.
Future work will focus on optimising the device design, hydrogel formulation
and ultimately assessing biocompatibility response in an in vivo setting