A Low Protein Binding Electrospun Membrane Filter for Efficient Biological Media Sterilization

This study exploited the water repelling hydrophobic nature of polycaprolactone (PCL) fibers for efficient filtration of water-based fluids toward development of an affordable sterile membrane filter by the process of electrospinning. Electrospun (ES) nanosized fibrous membranes of different thicknesses presented high force at break and minimal elongation supported syringe filtration. The membrane hydrophobicity facilitated easy filtration of small volumes of biological fluids (∼1 mL) without any wetting media loss. Compared to commercial filters, the developed electrospun PCL membrane filter (EPF) device exhibited excellent bacterial filtration without compromising the media quality. Electron microscopy analysis revealed bacterial entrapment onto PCL nanofibers that are in direct contact with the contaminated media. Mechanistically, an EPF with ∼0.8 mm thickness and high porosity created sinusoidal channels of different diameters that could effectively retard bacterial movement for the efficient filtration of up to 50 mL of contaminated biological media. Despite being hydrophobic, the PCL nanofiber filter had low protein binding, and its filtration quality was similar to commercial controls, assessed by cell viability assays. Thus, the EPF device can be an alternate filter sterilization platform for medical applications without compromising the filtrate's quality.