Abstract
Purpose :
Porcine decellularized conjunctiva (PDC) represents a promising alternative source for conjunctival reconstruction. Methods of its re-epithelialization in vitro with primary human conjunctival epithelial cells (HCEC) have already been established. However, a long-term storage method is required for a simplified clinical use of PDC. This study investigates the influence of several storage variants on the extracellular matrix of PDC.
Methods :
PDC were stored in (1) phosphate-buffered saline solution at 4 °C, (2) glycerol-containing epithelial cell medium at -80 °C or (3) dimethyl sulfoxide-containing epithelial cell medium at -196 °C in liquid nitrogen for six months. Fresh, non-stored decellularized PDC served as control. Histological structure, loosening of the extracellular matrix fibers and content of collagen and elastin were compared. Changes in biomechanical properties (elastic modulus, tensile strength, extensibility) were measured in uniaxial stress tests. To investigate the effect of the storage method on re-epithelialization, PDC were cultured with primary HCEC for 14 days following measurement of epithelialized PDC in histological sections (n = 4 - 10).
Results :
In all groups, PDC showed a well-preserved extracellular matrix without structural disruptions and with comparable fiber density (p ≥ .74). Collagen and elastin content were not significant different between the groups (p ≥ .18; p ≥ .13, respectively). With exception of significantly reduced tensile strength of PDC after storage at -196 °C (0.46 ± 0.21 MPa; p = .02), no significant differences were seen regarding elastic modulus, tensile strength and extensibility compared to control (0.87 ± 0.25 MPa, p ≥ .06). Mean values of re-epithelialized PDC surface ranged from 51.9 ± 8.8 % (-196 °C) to 78.3 ± 4.4 % (-80 °C) and did not differ significantly (p <.35).
Conclusions :
In conclusion, all examined storage methods were suitable for storing PDC for at least six months. All PDC were able to re-epithelialize, which rules out cytotoxic influences of the storage conditions and suggests preserved biocompatibility for in vivo application.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.