Use of sodium hyaluronate in combination with a blood derivative in the re-epithelialization of rabbit corneas

Purpose To analyze if using a bioadhesive (sodium hyaluronate or HaNa) in combination with a blood derivative (s-PRGF) improves the healing rate and quality of corneal epithelial ulcers. Methods Rabbit corneas removed 7 and 30 days after an in vivo re-epithelialization assay were include in paraffin and processed for haematoxylin–eosin staining or cryopreserved for immunofluorescent staining. In vitro proliferation and wound healing experiments were performed using the human corneal epithelial HCE cell line and rabbit primary corneal epithelial cultures. We studied the following treatments: 1) 90% s-PRGF 2) 0.22% NaHa 3) s-PRGF + NaHa 4) PBS as control treatment for the in vivo assay. All components in treatments 1, 2 and 3 were half the concentration for the in vitro assays, being 1% BSA the control treatment (4). To manufacture s-PRGF whole blood was collected by venipuncture from healthy volunteers or New Zealand rabbits, respectively. Results Healing rate was higher in cultures and in eyes under s-PRGF treatment than in those treated with HaNa or the combination of both. H-E sections at 30 days showed more cells in the anterior stroma in eyes under HaNa treatments. In agreement with it, Ki67 staining as well as in vitro proliferation assays demonstrated that HaNa stimulated cell proliferation. All treatments produced stratified and mature epithelia (CK3 positiveness) with barrier function (ZO-1 staining) and activation of limbal stem cells (CK15 staining), although the HaNa treated epithelia were the less organized. Moreover, eyes treated with only s-PRGF showed the best integrin β4 staining. Conclusions HaNa bioadhesive promotes epithelial and stromal cell proliferation, but does not improve the corneal healing capacity of s-PRGF. s-PRGF shows a better healing quality in terms of epithelial-stromal adhesion.