Electrospun controlled release anti-quorum sensing filter for biofouling prevention in MCE membranes

Abstract

The formation of biofilm on the surface of water filtration membranes results in decreased flux through the filter and output of contaminated water despite filtration. The reduction in clean water output due to biofilm diminishes filtration efficiencies and feasibility of filtration in regions where alternatives do not exist. In this work, we sought to lower biofouling concerns through examination of anti-quorum sensing (anti-QS) molecules in P. aeruginosa (PAO1). QS plays a critical initial role in biofilm formation. Therefore, we hypothesized that disruption of this communication mechanism at the filtration surface would result in lower biofilm growth and higher water outputs. An electrospun filter coating was developed to prevent biofilm formation on the surface of filtration membranes. The filter coating was deposited by electrospinning (ES) fibers that contained a polymer blend made up of one hydrophobic (polycaprolactone, PCL) and one hydrophilic (polyethylene glycol, PEG) polymer to provide controlled release of anti-quorum sensing molecules (Urolithin A) to prevent biofilm formation for an extended filtration test. Results showed that a 3:1 PCL to PEG polymer blend coating containing Urolithin A (200 µg/mL) provided significant physical disruption as well as molecular interruption of biofilm formation as compared to the pristine membrane (83.48 % reduction). While fibers exhibited smooth morphologies prior to nanofiltration tests, the fibers became porous after 4 hr tests in areas where PEG had dissolved and released Urolithin A. The controlled release of anti-QS molecules by electrospun fibers provided a significantly improved anti-biofilm methodology, improving biovolume reduction by 26.05 % and increasing flux by 52.78 % as compared to similar technologies reported. In addition to these findings, this work demonstrated Urolithin A disruption of PAO1 motility on agar (65.29 % reduction @ 100 µg/mL) and reduction in biofilm thickness (84.15 % reduction @ 200 µg/mL) by dissolution from electrospun fibers in liquid culture.