title: Antimicrobial efficacy of tobramycin polymeric nanoparticles for Pseudomonas aeruginosa infections in cystic fibrosis: formulation, characterisation and functionalisation with dornase alfa (DNase).
abstract: Inhaled antibiotics, such as tobramycin, for the treatment of Pseudomonas aeruginosa pulmonary infections are associated with the increase in life expectancy seen in cystic fibrosis (CF) patients over recent years. However, the effectiveness of this aminoglycoside is still limited by its inability to penetrate the thick DNA-rich mucus in the lungs of these patients, leading to low antibiotic exposure to resident bacteria. In this study, we created novel polymeric nanoparticle (NP) delivery vehicles for tobramycin. Using isothermal titration calorimetry, we showed that tobramycin binds with alginate polymer and, by exploiting this interaction, optimised the production of tobramycin alginate/chitosan NPs. It was established that NP antimicrobial activity against P. aeruginosa PA01 was equivalent to unencapsulated tobramycin (minimum inhibitory concentration 0.625mg/L). Galleria mellonella was employed as an in vivo model for P. aeruginosa infection. Survival rates of 90% were observed following injection of NPs, inferring low NP toxicity. After infection with P. aeruginosa, we showed that a lethal inoculum was effectively cleared by tobramycin NPs in a dose dependent manner. Crucially, a treatment with NPs prior to infection provided a longer window of antibiotic protection, doubling survival rates from 40% with free tobramycin to 80% with NP treatment. Tobramycin NPs were then functionalised with dornase alfa (recombinant human deoxyribonuclease I, DNase), demonstrating DNA degradation and improved NP penetration of CF sputum. Following incubation with CF sputum, tobramycin NPs both with and without DNase functionalisation, exhibited anti-pseudomonal effects. Overall, this work demonstrates the production of effective antimicrobial NPs, which may have clinical utility as mucus-penetrating tobramycin delivery vehicles, combining two widely used CF therapeutics into a single NP formulation. This nano-antibiotic represents a strategy to overcome the mucus barrier, increase local drug concentrations, avoid systemic adverse effects and improve outcomes for pulmonary infections in CF.
authors.affiliation: Centre for Infection and Immunity, Health Sciences Building, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7AE, Northern Ireland, UK; School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK.
authors.forename: Jill
authors.initials: J
authors.lastname: Deacon
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK.
authors.forename: Sharif M
authors.initials: SM
authors.lastname: Abdelghany
authors.affiliation: Centre for Infection and Immunity, Health Sciences Building, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7AE, Northern Ireland, UK.
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Quinn
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK.
authors.forename: Daniela
authors.initials: D
authors.lastname: Schmid
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK.
authors.forename: Julianne
authors.initials: J
authors.lastname: Megaw
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK.
authors.forename: Ryan F
authors.initials: RF
authors.lastname: Donnelly
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK.
authors.forename: David S
authors.initials: DS
authors.lastname: Jones
authors.affiliation: Centre for Infection and Immunity, Health Sciences Building, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7AE, Northern Ireland, UK.
authors.forename: Adrien
authors.initials: A
authors.lastname: Kissenpfennig
authors.affiliation: Centre for Infection and Immunity, Health Sciences Building, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7AE, Northern Ireland, UK.
authors.forename: J Stuart
authors.initials: JS
authors.lastname: Elborn
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK.
authors.forename: Brendan F
authors.initials: BF
authors.lastname: Gilmore
authors.affiliation: Centre for Infection and Immunity, Health Sciences Building, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7AE, Northern Ireland, UK.
authors.forename: Clifford C
authors.initials: CC
authors.lastname: Taggart
authors.affiliation: School of Pharmacy, Queen's University Belfast, 97 Lisburn Road, Belfast BT9 7BL, Northern Ireland, UK. Electronic address: c.scott@qub.ac.uk.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Scott
mesh_terms: D000328:Adult; D000464:Alginates / Q000737:chemistry; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D002626:Chemistry, Pharmaceutical; D048271:Chitosan / Q000737:chemistry; D003550:Cystic Fibrosis / Q000188:drug therapy; D004247:DNA / Q000378:metabolism; D003850:Deoxyribonuclease I / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006801:Humans; D008826:Microbial Sensitivity Tests; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry / Q000627:therapeutic use; D011552:Pseudomonas Infections / Q000188:drug therapy; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000254:growth & development; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D013183:Sputum / Q000378:metabolism; D014031:Tobramycin / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D000464:Alginates; D000900:Anti-Bacterial Agents; D006603:Hexuronic Acids; D011994:Recombinant Proteins; D020723:Glucuronic Acid; D004247:DNA; D048271:Chitosan; D003850:Deoxyribonuclease I; C568813:dornase alfa; D014031:Tobramycin
keywords: Alginate; Cystic fibrosis sputum; DNase; Nanoparticle; Pseudomonas aeruginosa; Tobramycin