Nanowerk reports that researchers have fabricated a film exhibiting asymmetric wettability—in other words, a film with both a superhydrophobic and a hydrophilic layer. Potentially suitable for wound-care applications, the technology could serve as a medical dressing in which the superhydrophobic surface on top protects the wound from dust and bacteria while the hydrophilic surface at the bottom delivers drugs that can accelerate wound healing or help avoid infections, according to Jian Ji, a professor in the department of polymer science engineering at Zhejiang University (Hangzhou, China).
The superhydrophobic surface is self-cleaning, antiwetting, and capable of limiting bacterial adhesion, while the hydrophilic surface can deliver antibacterial silver ions, Nanowerk notes. In addition, the film can be transferred to another interface, such as skin.
Ji comments that that the antiadhesion capability of the top surface results from the film’s combination of micro-nano hierarchical structure and superhydrophobicity, characteristics that promote antibacterial adhesion. The microstructure on the film ranges in size from 2 to 5 µm, Ji adds, which is close to the size of E. coli.