title: Development of Optimized, Inhalable, Gemcitabine-Loaded Gelatin Nanocarriers for Lung Cancer.
abstract: BACKGROUND
  Aerosol delivery of chemotherapeutic nanocarriers represents a promising alternative for lung cancer therapy. This study optimized gemcitabine (Gem)-loaded gelatin nanocarriers (GNCs) cross-linked with genipin (Gem-GNCs) to evaluate their potential for nebulized lung cancer treatment.
  
  
  METHODS
  Gem-GNCs were prepared by two-step desolvation and optimized through Taguchi design and characterized for physicochemical properties. Particle size and morphology were confirmed by scanning and transmission electron microscopy. In vitro release of Gem from Gem-GNCs performed in Dulbecco's phosphate-buffered saline and simulated lung fluid was evaluated to determine release mechanisms. Particle size stability was assessed under varying pH. Differential scanning calorimetry and powder X-ray diffraction were used to determine the presence and stability of Gem-GNC components and amorphization of Gem, respectively. Gem-GNC efficacy within A549 and H460 cells was evaluated using MTT assays. Mucus rheology upon treatment with Gem-GNCs, lactose, and normal saline control was measured. Andersen cascade impaction identified the aerodynamic particle size distribution of the nebulized formulation.
  
  
  RESULTS
  Gem-GNCs had particle size, zeta potential, entrapment efficiency, and loading efficiency of 178 ± 7.1 nm, -18.9 mV, 92.5%, and 9.1%, respectively. The Gem and formulation excipients where molecularly dispersed and configured amorphously. Gem-GNCs were stable at pH 5.4-7.4 for 72 hours. Gem release from Gem-GNCs was governed by non-Fickian controlled release due to diffusion/erosion from a matrix-based nanocarrier. Gem-GNCs elicited a 40% reduction of the complex viscosity η*(1 Hz) of human bronchial epithelial cell mucus containing 3 wt% solids to mimic mild airway disease. The nebulized Gem-GNCs had a mass median aerodynamic diameter (MMAD) of 2.0 ± 0.16 μm, geometric standard deviation (GSD) of 2.7 ± 0.16, and fine particle fraction (FPF) of 75.2% ± 2.4%. The Gem-GNC formulation did not outperform the Gem solution in A549 cells. However, in H460, Gem-GNCs outperformed the Gem IC50 reduction by ∼5-fold at 48 and 10-fold 72 hours.
  
  
  CONCLUSIONS
  Stable, effective, and sustained-release Gem-GNCs were developed. The nebulized Gem-GNCs had satisfactory MMAD, GSD, and FPF and the formulation reduced the dynamic complex viscosity of mucus consistent with increased mobility of nanoparticles.
authors.affiliation: 1 Translational Drug Delivery Research (TransDDR) Laboratory, Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawai'i at Hilo , Hilo, Hawai'i.
authors.forename: Susanne R
authors.initials: SR
authors.lastname: Youngren-Ortiz
authors.affiliation: 2 Department of Physics and Astronomy, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.|3 Marsico Lung Institute/CF Center, The University of North Carolina School of Medicine , Chapel Hill, North Carolina.
authors.forename: David B
authors.initials: DB
authors.lastname: Hill
authors.affiliation: 4 Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawai'i , Honolulu, Hawai'i.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Hoffmann
authors.affiliation: 1 Translational Drug Delivery Research (TransDDR) Laboratory, Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawai'i at Hilo , Hilo, Hawai'i.|5 The Lachman Institute for Pharmaceutical Analysis, Arnold & Marie Schwartz College of Pharmacy and Health Sciences, Long Island University-Brooklyn Campus , Brooklyn, New York.
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Morris
authors.affiliation: 6 Respiratory and Asthma Program, Lovelace Respiratory Research Institute , Albuquerque, New Mexico.
authors.forename: Edward G
authors.initials: EG
authors.lastname: Barrett
authors.affiliation: 7 Carolina Center for Interdisciplinary Applied Mathematics, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.
authors.forename: M Gregory
authors.initials: MG
authors.lastname: Forest
authors.affiliation: 1 Translational Drug Delivery Research (TransDDR) Laboratory, Department of Pharmaceutical Sciences, The Daniel K. Inouye College of Pharmacy, University of Hawai'i at Hilo , Hilo, Hawai'i.|8 Pii Center for Pharmaceutical Technology, Research Institute of Pharmaceutical Sciences, University of Mississippi , Oxford, Mississippi.|9 Translational Drug and Gene Delivery Research (TransDGDR) Laboratory, Department of Pharmaceutics and Drug Delivery, School of Pharmacy, University of Mississippi , Oxford, Mississippi.|10 Natural Products and Experimental Therapeutics Program, University of Hawai'i Cancer Center, University of Hawai'i , Honolulu, Hawai'i.
authors.forename: Mahavir B
authors.initials: MB
authors.lastname: Chougule
mesh_terms: D000072283:A549 Cells; D000280:Administration, Inhalation; D000336:Aerosols; D002152:Calorimetry, Differential Scanning; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D002626:Chemistry, Pharmaceutical / Q000379:methods; D003692:Delayed-Action Preparations; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D016503:Drug Delivery Systems; D065546:Drug Liberation; D005780:Gelatin; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000473:pathology; D053758:Nanoparticles; D010316:Particle Size; D014783:Viscosity; D014961:X-Ray Diffraction; D000093542:Gemcitabine
chemical_list: D000336:Aerosols; D003692:Delayed-Action Preparations; D003841:Deoxycytidine; D005780:Gelatin; D000093542:Gemcitabine
keywords: Taguchi factorial design; gelatin; gemcitabine; inhalation; lung cancer; nanoparticles