Surface modification of polystyrene particles for specific antibody adsorption

Polycyclic aromatic polymer nanoparticles show potent infectious particle adsorption capability

Nonspecific viral adsorption by polymer nanoparticles is more economical and superior in terms of operating cost and energy efficiency than viral adsorption using virus-specific antibodies and filtration techniques involving size exclusion in the order of tens of nanometres. In this study, we synthesised four types of polycyclic aromatic polymer (ArP) nanoparticles with different structures and evaluated their virus adsorption capability for infectious particles of the newly emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). ArP nanoparticles with a diameter of approximately 500 nm were prepared by one-pot precipitation polymerisation using structural isomers of bifunctional dihydroxynaphthalene (1,5-dihydroxynaphthalene and 2,6-dihydroxynaphthalene) as phenol monomers, as well as 3-hydroxybenzoic acid and 3-aminophenol as comonomers to introduce carboxylic acid and amino groups, respectively. This wide range of phenolic monomers offers a powerful molecular design capability, enabling the optimisation of surface properties for the adsorption of various infectious virus particles. The virus adsorption capacity of the ArP nanoparticles exceeded 20 000 plaque-forming units and was found to be correlated with the nitrogen (primary and secondary amines) and quinone contents on the ArP nanoparticle surface. Furthermore, a polyvinylidene difluoride membrane filter uniformly coated with the ArP nanoparticles could remove viruses by filtration in a flow system.

Fc-mediated transport of nanoparticles across airway epithelial cell layers

In a study directed towards non-invasive delivery of therapeutic biomacromolecules, we examined whether surface modification of sub-200 nm model nanoparticles with the Fc portion of IgG promotes their cell uptake and transport across the airway epithelial cells. The study initially confirms the expression of the relevant receptor, namely neonatal Fc receptor (FcRn), by Calu-3 cell layers simulating the airway epithelium and demonstrates FcRn-mediated cell association, internalization and transcellular transport of molecular IgG. Surface decoration of nanoparticles with the Fc portion of IgG enhanced both cell uptake and translocation of the particulate system across the cell layers, in a manner strongly suggesting FcRn involvement in these processes. The study further demonstrates the potential of Fc-modified nanoparticles to 'shuttle' a model therapeutic antibody fragment across the epithelial cell layers. Fc-modified nanoparticles are transported in the μg/h/cm(2) range, presenting a substantial increase in transport capacity in comparison to molecular IgG (ng/h/cm(2) range), therefore warranting consideration of the FcRn transcytotic pathway for further investigation as a means to achieve transmucosal delivery of nanoparticulate systems that could act as carriers of a range of biotherapeutics.

Radical graft polymerization of styrene sulfonate on poly(ethylene terephthalate) films for ACL applications: "grafting from" and chemical characterization

The purpose of this study is to develop a reliable method of functionalizing poly(ethylene terephthalate) with bioactive polymers to produce a "biointegrable" artificial anterior cruciate ligament. Radical graft polymerization of the sodium salt of styrene sulfonate (NaSS) onto poly(ethylene terephthalate) (PET) films was performed using the "grafting from" technique. Prior to the grafting, the surfaces of poly(ethylene terephthalate) films were activated by ozonation to generate peroxide and hydroperoxide reactive species on the PET film surfaces. The radical polymerization of NaSS was initiated by thermal decomposition of the hydroperoxides. The grafted PET surfaces were characterized by a toluidin blue colorimetric method, X-ray photoelectron spectroscopy, contact angle measurements, and atomic force microscopy. The influence of ozonation time, monomer concentration, and temperature on NaSS grafting ratios was examined. A total of 30 min of ozonation followed by grafting from a 15% NaSS solution at 70 degrees C for 90 min or more resulted in attachment of poly(NaSS) chains to the PET film surfaces.