Abstract
Purpose :
The application of amniotic membrane to stimulate healing of corneal abrasions is coupled with difficulties in procuring, sterilizing, and storing the tissue. Luna is developing a unique biomaterial capable of mimicking the healing properties of amniotic membrane using a nanofiber reinforced hydrogel. Luna performed in vitro and ex vivo characterization of the biological, mechanical, and optical properties of these dressings to investigate applications in corneal wound healing.
Methods :
Nanofibers were created on the Elmarco NanoSpider, and the hydrogel component was incorporated using custom-designed dual collection or negative pressure fabrication processes. Nanofiber alignment was determined using the FibrilTool ImageJ plugin. Transparency was determined using UV-Vis spectroscopy at 550 nm, and an Abbe Refractometer was used to quantify refractive index. Physical handling capabilities were quantified under tension (20 mm/min). Human adipose derived mesenchymal stem cells (ADMSCs) were cultured in direct contact with the samples for investigation of cytocompatibility and stem cell delivery potential. Angiogenesis was studied using human umbilical vein endothelial cells and assessing samples for resultant tube formation. Photochemical tissue bonding (PTB) was applied using excised rabbit eyeballs and a custom-built light delivery device (Iridix OcuLight GL laser, 532 nm at 0.25 W) to suturelessly adhere dressings to the corneal surface with rose bengal.
Results :
Prototype bandages were constructed with transparencies of 60%-90% depending on production method and refractive indices of 1.34 to approximate the native cornea (1.37). Prototypes demonstrated elastic moduli of 6 MPa and stability in simulated tear solution for 1 week with controlled degradation over 4 weeks. Cytocompatibility testing with ADMSCs showed the dressings non-toxic as compared to cellular controls and capable of delivering cultured stem cells to the wound bed. Luna also confirmed the dressings will not induce neovascularization of the ocular surface. Dressings were suturelessly adhered to the surface of ex vivo eyeballs using PTB with successful demonstration of repressurization.
Conclusions :
Luna fabricated a nanofiber-reinforced hydrogel to stimulate corneal wound healing following severe surface injury. The dressing was found to have the optical, mechanical, and biological properties necessary for ocular applications. In vivo studies are being initiated.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.