Abstract
Purpose :
Human adipose stem cells (hASCs) are an appealing cell source for corneal stromal repair and regeneration due to their capacity to differentiate towards corneal keratocytes and good availability from healthy adult donors. Limbal epithelial stem cells differentiated from human pluripotent stem cells (hPSC-LESCs) have potential to regenerate the corneal epithelium. We fabricated a tissue adhesive hyaluronan (HA)-based hydrogel, in which these two cell types can be implanted into corneal defects for simultaneous therapeutic effect of both the stroma and the epithelium.
Methods :
hASCs were obtained from Tampere University Hospital (Tampere, Finland) under patients’ informed consent and approval of the ethical committee. LESCs were differentiated from hPSCs using previously established methods. For the fabrication of HA-based hydrogels, native HA was functionalized with aldehyde derivatives (HA-Ald) and hydrazide derivatives by conjugating carbodihydrazide and tissue adhesive dopamine units (HA-DA-CDH). The hASCs were first encapsulated within the HA-hydrogels, and the hydrogel surface was then conjugated with adhesion peptides for the attachment of hPSC-LESCs. Cell survival within and on the surface of the hydrogels was studied using live/dead staining and cell proliferation assays. Materials were characterized for their chemical and physical properties and their degradation kinetics. Functionality of the hASC and hPSC-LESC-containing HA-hydrogels were studied in a porcine corneal organ culture model.
Results :
The HA-hydrogels gelated rapidly and the hydrogels remained stable for two weeks of in vitro culture. The hASCs remained viable inside the hydrogels for the entire culture period. Covalent grafting of the cell adhesion peptides to the hydrogel surface increased the amount of attached hPSC-LESCs. The implantation of the HA-hydrogels into stromal defects in the corneal organ culture model was successful, and the preformed gels were tissue adhesive, requiring no other means of immobilization to the cornea.
Conclusions :
The post-gelation surface modification of hydrogels enabled simultaneously culture of both hASCs inside the hydrogel and hPSC-LESC on the surface for regeneration of the corneal stroma and epithelium, respectively. The tissue adhesive dopamine group in the hydrogel facilitated the implantation of the tissue engineered constructs to corneal defects in the corneal organ culture.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.