Abstract
Purpose :
Corneal injuries account for 3% of all emergency visits, with improper wound healing resulting in corneal scarring. Current methods to treat corneal wounds involve frequent doses of antibiotic and anti-inflammatory eye drops. The low bioavailability of these drugs requires frequent dosing. Patients wear bandage contact lenses in conjunction with this regimen to minimise the discomfort from blinking and protect the cornea during the healing process, though they have limited therapeutic capabilities. Utilizing 3D digital light processing (DLP), a drug-loaded methacrylated Vitamin E (VEMA) ring was directly printed into a multi-material therapeutic contact lens.
Methods :
The ring-embedded lenses were designed using a CAD software. The lens formulations consist of a 2-hydroxyethyl methacrylate (HEMA) and poly(ethylene glycol) diacrylate (PEGDA) blend, with lithium phenyl-2,4,6-trimethylbenzoylphosphinate as the photoinitiator. Modified formulations with VEMA and 3-[Tris(trimethylsiloxy)silyl]propyl methacrylate (TRIS) + VEMA were produced to examine their printability to be used for the drug-loaded ring. The multi-material lens was printed layer-by-layer, with the PEGDA/HEMA formulation being substituted for the VEMA formulation in the ring layers. FTIR and TEM imaging to was done to examine the morphology and composition of the printed lenses. Sessile drop contact angle testing was performed to observe the hydrophobicity of the single-material prints.
Results :
FTIR confirmed VEMA and VEMA+TRIS content in the prints. TEM images showed uniformity of the PEGDA/HEMA prints whereas the modified formulations show distinct regions of separation due to poor miscibility between the hydrophilic and hydrophobic components. The images show the addition of TRIS improved the miscibility of VEMA with the PEGDA/HEMA phase. Contact angle showed a decrease in wettability from PEGDA/HEMA to VEMA prints, with a further decrease in VEMA+TRIS prints.
Conclusions :
We can produce single and multi-material lenses through 3D printing and directly print a drug-loaded ring within a lens. Further development may entail a multi-drug system capable of sustained release based on both hydrophilic and hydrophobic drugs.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.