Electrospun Zwitterionic Poly(Sulfobetaine Methacrylate) for Nonadherent, Superabsorbent, and Antimicrobial Wound Dressing Applications

Zwitterionic poly(sulfobetaine methacrylate) (PSBMA) has been well studied for its superhydrophilic and ultralow biofouling properties, making it a promising material for superabsorbent and nonadherent wound dressings. Electrospinning provides multiple desirable features for wound dressings, including high absorptivity due to high surface-area-to-volume ratio, high gas permeation, and conformability to contour of the wound bed. The goal of this work is to develop a fibrous membrane of PSBMA via electrospinning and evaluate its properties related to wound dressing applications. Being superhydrophilic, PSBMA fibers fabricated by a conventional electrospinning method would readily dissolve in water, whereas if cross-linker is added, the formation of hydrogel would prevent electrospinning. A three-step polymerization-electrospinning-photo-cross-linking process was developed in this work to fabricate the cross-linked electrospun PSBMA fibrous membrane. Such electrospun membrane was stable in water and exhibited high water absorption of 353% (w/w), whereas the PSBMA hydrogel only absorbed 81% water. The electrospun membrane showed strong resistance to protein adsorption and cell attachment. Bacterial adhesion studies using Gram negative P. aeruginosa and Gram positive S. epidermidis showed that the PSBMA electrospun membrane was also highly resistant to bacterial adhesion. The Ag+-impregnated electrospun PSBMA membrane was shown microbicidal, against both S. epidermidis and P. aeruginosa. Such electrospun PSBMA membrane is ideal for a novel type of nonadherent, superabsorbent, and antimicrobial wound dressing. The superior water absorption aids in fluid removal from highly exudating wounds while keeping the wound hydrated to support healing. Because of the resistance to protein, cell, and bacterial adhesion, the dressing removal will neither cause patients' pain nor disturb the newly formed tissues. The dressing also prevents the attachment of environmental bacteria and offers broad-spectrum antimicrobial activity. It is the first work to develop the water-stable electrospun PSBMA membrane, which has great potential for wound dressing and other applications.