title: Slow-release nanoparticle-encapsulated delivery system for laryngeal injection.
abstract: OBJECTIVE
  There is a need for a slow-release system for local delivery of therapeutics to the larynx. Most therapeutic substances, such as steroids or chemotherapeutic agents that are injected into the larynx are cleared rapidly. Repeated laryngeal injection of these substances at short intervals is impractical. Injectable encapsulated poly(lactide-co-glycolide) (PLGA) nanoparticles offer a potential slow-release delivery system for biologically active substances in the larynx.
  
  
  METHODS
  Controlled animal study.
  
  
  METHODS
  PLGA nanoparticles were fabricated using a double emulsion method and were loaded with Texas Red-dextran (NPTR), hepatocyte growth factor (NPHGF), and bovine serum albumin (NPBSA). In vitro release of NPTR, NPBSA, and NPHGF was determined over approximately 2 weeks to assess potential duration of PLGA nanoparticle delivery. In vivo release of NPTR was assessed in a murine vocal fold injection model. The transcriptional effect of NPHGF on procollagen was measured in vitro to assess whether released growth factor retained functionality.
  
  
  RESULTS
  In vitro release kinetics demonstrated slow release of NPTR, NPBSA, and NPHGF over 12 to 14 days. In vitro NPTR release correlated with in vivo results. In vivo presence of NPTR occurred up to 7 days compared to 1 day for Texas Red control. In addition, NPHGF ameliorated transforming growth factor-beta induced procollagen in vitro in 3T3 fibroblast cells.
  
  
  CONCLUSIONS
  The results demonstrate the potential utility of nanoparticle encapsulation as an effective method for long-term delivery of specific drugs and biologically active substances to the larynx.
authors.affiliation: Emory Voice Center, Department of Otolaryngology-Head and Neck Surgery, Emory University School of Medicine, Atlanta, Georgia, USA.
authors.forename: Vasantha L
authors.initials: VL
authors.lastname: Kolachala
authors.forename: Oswaldo A
authors.initials: OA
authors.lastname: Henriquez
authors.forename: Samantha
authors.initials: S
authors.lastname: Shams
authors.forename: Justin S
authors.initials: JS
authors.lastname: Golub
authors.forename: Young-tae
authors.initials: YT
authors.lastname: Kim
authors.forename: Hamed
authors.initials: H
authors.lastname: Laroui
authors.forename: Edilson
authors.initials: E
authors.lastname: Torres-Gonzalez
authors.forename: Kenneth L
authors.initials: KL
authors.lastname: Brigham
authors.forename: Mauricio
authors.initials: M
authors.lastname: Rojas
authors.forename: Ravi V
authors.initials: RV
authors.lastname: Bellamkonda
authors.forename: Michael M
authors.initials: MM
authors.lastname: Johns
mesh_terms: D016475:3T3 Cells; D000818:Animals; D003692:Delayed-Action Preparations / Q000008:administration & dosage*; D004655:Emulsions; D005347:Fibroblasts / Q000187:drug effects; D017228:Hepatocyte Growth Factor / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000494:pharmacology; D007830:Larynx / Q000187:drug effects*; D008657:Metabolic Clearance Rate / Q000502:physiology; D051379:Mice; D053769:Nanocapsules; D011098:Polyglactin 910; D011347:Procollagen / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D003692:Delayed-Action Preparations; D004655:Emulsions; D053769:Nanocapsules; D011347:Procollagen; D011098:Polyglactin 910; D017228:Hepatocyte Growth Factor