Collagen-grafted temperature-responsive nonwoven fabric for wound dressing

Polypropylene (PP) nonwoven fabric (NWF) was modified by direct current pulsed plasma followed by grafting with acrylic acid (AAc) to improve its surface hydrophilicity and to introduce carboxylic acid group on the surface for further conjugation with bioactive collagen biomolecule. To endow temperature-responsive property, PP-g-collagen NWF was further modified with poly(N-isopropylacrylamide) (PNIPAAm). Experimental results demonstrated that the amount of AAc and collagen grafted were 43.4 nmole/cm2, and 35.9 μg/cm2, respectively. The amount of PNIPAAm immobilized was 213 μg/cm2. The physical properties, surface chemical composition, and microstructure of the NWFs were characterized. From animal study, modified NWFs were found to promote wound healing with bigraft PP-g-collagen-g-PNIPAAm NWF showing the best performance.