Wet-stable PLGA-PCL electrospun membranes as synthetic scaffolds for corneal applications

Corneal impairment is the fourth leading cause of blindness worldwide. Current therapies often use biodegradable amniotic membranes (AMs) to assist in transferring limbal stem cells or explants to the cornea. Surgeons have extensive experience with these, but they are human biological tissue and must be sourced and used under tissue bank conditions to reduce the risk of disease transmission. Thus, accessibility and safety remain concerns in their use. Accordingly, the development of synthetic scaffolds to support limbal tissue outgrowth is an attractive, reproducible and accessible alternative. This group has made good progress towards this membrane design using a Polylactide-co-Glycolide (PLGA) electrospun membrane but has identified problems with handling and integrity of the membrane once wet. Our aim, therefore, is to improve the integrity and pliability of these cell delivery membranes in wet environments without compromising their ability to act as cell carriers for corneal regeneration. Electrospun scaffolds with different mechanical properties were manufactured by blending different concentrations of PLGA and Polycaprolactone (PCL). All the manufactured membranes supported cell outgrowth when tested with porcine and human limbal explants. Scaffolds were characterised under dry and wet conditions using scanning electron microscopy and uniaxial tensile testing. Blends with a relatively high proportion of PCL (30%) were able to maintain their mechanical properties under both dry and wet conditions and were flexible in handling. This study demonstrates that PLGA-PCL electrospun membranes with 30% PCL content retain good mechanical properties in a wet environment, making them easy to handle while retaining the ability to support limbal tissue attachment and cell outgrowth. This makes them a viable synthetic alternative to the AM.