title: Controlling microencapsulation and release of micronized proteins using poly(ethylene glycol) and electrospraying.
abstract: The fabrication of tailored microparticles for delivery of therapeutics is a challenge relying upon a complex interplay between processing parameters and materials properties. The emerging use of electrospraying allows better tailoring of particle morphologies and sizes than current techniques, critical to reproducible release profiles. While dry encapsulation of proteins is essential for the release of active therapeutics from microparticles, it is currently uncharacterized in electrospraying. To this end, poly(ethylene glycol) (PEG) was assessed as a micronizing and solubilizing agent for dry protein encapsulation and release from electrosprayed particles made from polycaprolactone (PCL). The physical effect of PEG in protein-loaded poly(lactic-co-glycolic acid) (PLGA) particles was also studied, for comparison. The addition of 5-15 wt% PEG 6 kDa or 35 kDa resulted in reduced PCL particle sizes and broadened distributions, which could be improved by tailoring the electrospraying processing parameters, namely by reducing polymer concentration and increasing flow rate. Upon micronization, protein particle size was reduced to the micrometer domain, resulting in homogenous encapsulation in electrosprayed PCL microparticles. Microparticle size distributions were shown to be the most determinant factor for protein release by diffusion and allowed specific control of release patterns.
authors.affiliation: Tissue Repair and Regeneration Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Australia; Biomaterials and Tissue Morphology Group, Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Australia; Regenerative Medicine Group, Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Australia. Electronic address: n.bock@qut.edu.au.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Bock
authors.affiliation: Tissue Repair and Regeneration Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Australia.
authors.forename: Tim R
authors.initials: TR
authors.lastname: Dargaville
authors.affiliation: Biomaterials and Tissue Morphology Group, Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Australia.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Woodruff
mesh_terms: D000336:Aerosols; D002626:Chemistry, Pharmaceutical; D003692:Delayed-Action Preparations; D004058:Diffusion; D004337:Drug Carriers; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives / Q000737:chemistry; D005612:Freeze Drying; D007700:Kinetics; D019344:Lactic Acid / Q000737:chemistry; D008970:Molecular Weight; D010316:Particle Size; D011091:Polyesters / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry*; D011100:Polyglycolic Acid / Q000737:chemistry; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D012709:Serum Albumin / Q000737:chemistry*; D012995:Solubility; D013678:Technology, Pharmaceutical / Q000379:methods*
chemical_list: D000336:Aerosols; D003692:Delayed-Action Preparations; D004337:Drug Carriers; C518288:FITC-albumin; D011091:Polyesters; D012709:Serum Albumin; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; C016240:polycaprolactone; D011100:Polyglycolic Acid; D019344:Lactic Acid; D011092:Polyethylene Glycols; D016650:Fluorescein-5-isothiocyanate
keywords: Drug delivery; Electrospraying; Encapsulation; In vitro release; Micronization; Microparticles; Poly(ethylene glycol); Polycaprolactone; Protein