INHIBITORY EFFECTS OF TIMOLOL MALEATE AND ITS PRESERVATIVE BENZALKONIUM CHLORIDE ON CORNEAL EPITHELIAL MIGRATION IN A RABBIT ORGAN CULTURE SYSTEM

Purpose: Timolol maleate, the ophthalmic solutions, is frequently prescribed for glaucoma, although the use of this drop is likely to interfere with wound healing in corneal surgeries. A possible factor that may influence rates of corneal wound healing is how the solutions are preserved. The purpose of this study to evaluate the effect of commercially prepared topical timolol maleate and its preservative benzalkonium chloride (BAC-) 0.0004% and 0.001% or its preservative free effect on the rate of corneal epithelial wound healing. Methods: In this study, New Zealand white rabbits corneas (n= 80) were removed and 7mm epithelia were abraded mechanically. The abraded corneal epithelia were incubated in modified supplemental hormonal epithelial media (SHEM) containing a) timolol maleate drop 0.005% and 0.05% supplied with BAC+ (0.001%) and b) BAC- (preservative free) timolol maleate (purified form) 0.005% and 0.05% and c) along with BAC+ 0.001% and 0.0004% concentration, d) only BAC with 0.001% and 0.0004% concentration. The media containing timolol maleate and BAC was replaced every 24 hours. Photographic documentation of Richardson stained, non-healed areas, was performed at time points 0, 24, 48, 72, 96 and 120 hours of post wounding. Results: The timolol maleate (0.05%) BAC accelerated wound healing and wound closure significantly (p Conclusion: Corneal organ culture model has confirmed that topically applied timolol maleate inhibited corneal wound healing with its preservative BAC, although the appropriate randomized clinical assessment are essential to certify these reports

Changes in albumin precursor and heat shock protein 70 expression and their potential role in response to corneal epithelial wound repair

Many proteins displayed differential expression (either up- or down-regulation) when proteome of migrating and non-migrating epithelium was assessed using 2-DE and ESI-Q-TOF MS/MS. From the up-regulated set, we have identified for the first time a 69-kDa albumin precursor protein with four peptides sequences and 70-kDa heat shock protein (hsp70) with one peptide in the active phase of cell migration (48 h) during the healing process. Western blot analysis was used to further characterize these proteins at different phases (24, 48 and 72 h) of healing. An increase in the mRNA expression (measured using RT-PCR) in the active migration phase (48 h) for albumin precursor and hsp70 was also observed. Furthermore, co-immunoprecipitation studies with anti-albumin precursor and anti-hsp70 antibodies, followed by immunoblotting with antifibronectin antibody demonstrated a novel and biologically relevant interaction between albumin precursor protein and fibronectin in corneal epithelial wound healing but not with hsp70. The increased gene and protein expression of albumin and hsp70 during the active phase of cell migration (48 h) in the corneal epithelium suggests their possible role in corneal wound healing. These findings may have broader implications for developing therapeutic strategies for treating wound healing disorders

Building bridges through science

WOS: 000415310800007PubMed ID: 29144972Science is ideally suited to connect people from different cultures and thereby foster mutual understanding. To promote international life science collaboration, we have launched "The Science Bridge'' initiative. Our current project focuses on partnership between Western and Middle Eastern neuroscience communities.Medical Research Council [MC_UP_1202/5