Abstract
Abstract: :
Purpose: To evaluate the feasibility of human amniotic membrane (HAM) and acellular dermis (AD) grafts as substrates for cultured human conjunctival cells by monitoring their ability to attach to the substrates and grow. Conjunctival cellular grafts containing goblet and epithelial cells would be useful for ocular and inner palpebral surface reconstruction. Methods: Normal human conjunctival tissue was removed during routine periocular surgery. Explant cultures were established on glass coverslips or cells inserts and grown in RPMI medium supplemented with 10% FBS for 2 weeks. Prior to seeding on HAM and AD, conjunctival cells were labeled using either red (PKH26) or green (PKH67) fluorescent linkers as a means of identification. In each experiment, cells were seeded onto both surfaces of the grafts (HAM–Epithelium/Stroma ; AD–Basement membrane/Dermis). Cells were also seeded onto glass coverslips as controls. Cultures were fixed with 4% paraformaldehyde after 7 days. Cells were counted and subjected to immunohistochemical evaluation of Helix pomatia agglutinin ; HPA (goblet cells) and Banderia lectins (stratified squamous epithelial cells). Results: Cell attachment per surface was determined by counting the number of cells present in five identical areas (0.55x0.84mm) at 20x magnification. On average, 33 cells were present on the epithelial side of HAM and 57 cells on the stromal side. In contrast, 14 cells were counted on the basement membrane side of AD compared to 8 cells on the dermal side. With immunohistochemistry, the cell population on the epithelial side of HAM was found to be equally distributed among goblet cells (HPA) and stratified squamous epithelial cells (Banderia lectins). On the stromal side of HAM, the population of goblet cells (HPA) was twice the amount of stratified squamous epithelial cells (Banderia lectins). No cells on both sides of AD was positive for HPA or Banderia lectins. Conclusions: The stromal surface of HAM provides the best substrate for proliferation of normal human conjunctival cells. Future studies needed to optimize mechanical elements of grafts for broad clinical applications.