title: Nano-stereocomplexation of polylactide (PLA) spheres by spray droplet atomization.
abstract: A direct, efficient, and scalable method to prepare stereocomplexed polylactide (PLA)-based nanoparticles (NPs) is achieved. By an appropriate combination of fabrication parameters, NPs with controlled shape and crystalline morphology are obtained and even pure PLA stereocomplexes (PLASC) are successfully prepared using the spray-drying technology. The formed particles of varying D- and L-LA content have an average size of ≈400 nm, where the smallest size is obtained for PLA50, which has an equimolar composition of PLLA and PDLA in solution. Raman spectra of the particles show the typical shifts for PLASC in PLA50, and thermal analysis indicates the presence of pure stereocomplexation, with only one melting peak at 226 °C. Topographic images of the particles exhibit a single phase with different surface roughness in correlation with the thermal analysis. A high yield of spherically shaped particles is obtained. The results clearly provide a proficient method for achieving PLASC NPs that are expected to function as renewable materials in PLA-based nanocomposites and potentially as more stable drug delivery carriers.
authors.affiliation: Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-100 44, Stockholm, Sweden.
authors.forename: Veluska
authors.initials: V
authors.lastname: Arias
authors.forename: Karin
authors.initials: K
authors.lastname: Odelius
authors.forename: Ann-Christine
authors.initials: AC
authors.lastname: Albertsson
mesh_terms: D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry*; D013237:Stereoisomerism; D013499:Surface Properties
chemical_list: D011091:Polyesters; C033616:poly(lactide)
keywords: biodegradable; nanoparticles; polylactides; spray-drying; stereocomplexes