Evaluation of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer-coated dressing on surgical wounds

The ideal dressing material is bio-inert and keeps the wound site moist. It is equally important that no regenerative tissue is peeled off on the removal of the dressing. 2-Methacryloyloxyethyl phosphorylcholine (MPC) has a phospholipid polar group that mimics a biomembrane. We prepared poly [MPC-co-n-dodecyl methacrylate (DMA)] (PMD), using conventional radical polymerization with 2,2'-azobisisobutyronitrile as an initiator, and coated it on polyurethane (PU; Tecoflex ^® 60 Thermedics Inc.) membrane. Full-thickness surgical wounds were made on the dorsal skin of rats and wound healing was compared under the following three conditions: air-exposed control (no dressing), PU dressing, and PMD dressing. At 3, 4 and 7 days after the operation, the wound sizes of the PMD dressings were smaller than the non-dressed wound, and at 6 and 7 days after the operation, the wound sizes of PU dressing were smaller than that of the air-exposed group. But there were no significant difference between the PMD dressing group and PU dressing group. Histologically, scab formation was not observed on the PU or PMD-dressed wounds. However, in the air-exposed control, a scab was formed and re-epithelialization of the wound site was prevented. Additionally, no damage was observed in the histological section of PMD dressed wound after the wound was cured. These results indicate that PMD dressing (PMD-coated PU membrane) has the potential to provide an inert environment for wound healing as well as PU.