title: Controlling solid lipid nanoparticle adhesion by polyelectrolyte multilayer surface modifications.
abstract: This study addresses the tunability of polyelectrolyte multilayers (PEM) toward adsorption of solid lipid nanoparticles (SLN). In SLN production for pharmaceutical applications, repellence from production equipment is desired while targeted adsorption is necessary for the functionalization of surfaces. SLN containing triglyceride/phospholipid or wax matrices were exposed to different PEM (consisting of poly(allylamine hydrochloride) (PAH), poly(diallyldimethylammonium chloride), and poly(acrylic acid)). PEM varied regarding layer architecture and surface properties by means of deposition pH, top layer variation, PEGylation with poly(acrylic acid)-graft-poly(ethylene glycol) copolymer, and thermal crosslinking. FTIR-ATR and SEM revealed SLN adhesion depending on PEM composition. Particle adsorption was tunable toward attraction as well as repellence: PEGylated PEM displayed lowest adsorption while PEM capped with PAH provided the strongest attraction of particles. Examinations at elevated temperatures resembled production conditions of SLN where these are processed as emulsions. Crystalline triglyceride SLN displayed high anisometry and, consequently, a large specific surface area. These platelets were more adherend than spherical droplets from the same formulation as an emulsion. Wax-based nanoparticles showed spherical shape, both in crystalline and molten state. However, adsorption was fostered as the fluidity of the disperse phase increased upon melting. Additionally, coalescence of adsorbed droplets took place, further increasing adsorption.
authors.affiliation: Institut für Pharmazeutische Technologie, TU Braunschweig, Braunschweig, Germany.
authors.forename: Jan Henrik
authors.initials: JH
authors.lastname: Finke
authors.forename: Hannah
authors.initials: H
authors.lastname: Schmolke
authors.forename: C-P
authors.initials: CP
authors.lastname: Klages
authors.forename: Christel C
authors.initials: CC
authors.lastname: Müller-Goymann
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000268:Adhesiveness; D000327:Adsorption; D003460:Crystallization; D016503:Drug Delivery Systems; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles; D010743:Phospholipids / Q000737:chemistry; D011073:Polyamines / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D011095:Polyethylenes / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013696:Temperature; D014280:Triglycerides / Q000737:chemistry; D014885:Waxes / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D010743:Phospholipids; D011073:Polyamines; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; D014280:Triglycerides; D014885:Waxes; C041004:poly-N,N-dimethyl-N,N-diallylammonium chloride; C063994:polyallylamine; D011092:Polyethylene Glycols; C006903:carbopol 940