Nanoparticulate drug delivery systems for pseudomonas aeruginosa infected lungs in cytic fibrosis

Current pulmonary treatments against Pseudomonas aeruginosa infections in cystic fibrosis (CF) lung suffer from deactivation and immobilization of the drug in thick and viscous biofilm/mucus blend, along with the general antibiotic resistance. The present work suggests pulmonary antibiotic delivery with high load, capable of penetrating the tight mesh of biofilm/mucus as a solution to existing treatment bottlenecks. The potential use of nanoparticulate drug delivery systems to improve the treatment efficiency of lung infections in CF lungs is investigated. First chapter describes counter-ion complexes as a strategy to enhance drug load and demonstrates its applicability to different antibiotic classes, as well as counter-ions. The second chapter focuses on the drug delivery system development and its optimization via design-of-experiments approach. For the proof-of-concept studies, biodegradable and biocompatible poly (lactic-co-glycolic acid) was suggested and ciprofloxacin was used as model drug substance. MicroJet Reactor (MJR) technology, a precise preparation technique performed under controlled conditions, was employed. Effect of each process parameter was evaluated to ensure quality-by-design. Final chapter is dedicated to physico-chemical and in vitro characterization of the optimized nanoparticles.Overall, the new established approach offers counter-ion complex loaded PLGA NPs as promising pulmonary nano drug delivery system against P. aeruginosa infections in CF lung.Behandlungen von Pseudomonas aeruginosa Infektionen der Lunge von zystischer Fibrose (CF) Patienten, leiden unter Deaktivierung und Immobilisierung des Medikaments in dicken und viskosen Biofilm / Schleim Mischungen, zusammen mit der allgemeinen Antibiotika- Resistenz. Die vorliegende Arbeit schlägt eine pulmonale Antibiotika Verabreichung mittels Nanopartikeln mit hoher Wirkstoffbeladung vor, die in der Lage sind, das enge Maschenwerk von Biofilm / Schleim zu durchdringen, als eine Lösung für bestehende Behandlungsengpässe. Die potenzielle Verwendung von nanopartikulären Drug Delivery-Systemen, zur Verbesserung der Behandlungseffizienz von Lungeninfektionen bei Patienten mit CF, wird untersucht. Das erste Kapitel beschreibt Gegenion-Komplexe als Strategie zur Verbesserung der Wirkstoffbeladung und zeigt ihre Anwendbarkeit auf verschiedene Antibiotika-Klassen sowie Gegenionen. Das zweite Kapitel konzentriert sich auf die Entwicklung der Drug Delivery- Systeme sowie deren Optimierung durch einen Design-of-Experiments Ansatz. Für die Machbarkeitsstudien wurde das biologisch abbaubare und biokompatible Poly (lactid-coglycolid) eingesetzt und Ciprofloxacin als Modell-Wirksubstanz verwendet. Die Mikrojetreaktor (MJR) Technologie wurde dafür eingesetzt, da sie eine präzise Herstellung unter kontrollierten Bedingungen ermöglicht. Die Auswirkung jedes Prozessparameters wurde evaluiert, um quality-by-design sicherzustellen. Das abschließende Kapitel widmet sich der physikalischchemischen und in vitro-Charakterisierung der optimierten Nanopartikel. Insgesamt bietet der neu etablierte Ansatz, von Gegenion-Komplex beladenen PLGANanopartikeln, vielversprechende pulmonale Nano-Drug Delivery-Systeme gegen P. aeruginosa-Infektionen in Lungen von CF-Patienten.Bundesministerium für Bildung und Forschung (BMBF) - FiDel-Projek

Reliable release testing for nanoparticles with the NanoDis System, an innovative sample and separate technique

One of the critical quality attributes of nanoparticle formulations is drug release. Their release properties should therefore be well characterized with predictive and discriminative methods. However, there is presently still no standard method for the release testing of extended release nanoformulations. Dialysis techniques are widely used in the literature but suffer from severe drawbacks. Burst release of formulations can be masked by slow permeation kinetics of the free drug through the dialysis membrane, saturation in the membrane, and absence of agitation in the membrane. In this study, the release profile of poly(lactic co-glycolic) (PLGA) nanocapsules loaded with all-trans retinoic acid was characterized using an innovative sample and separate set-up, the NanoDis System, and compared to the release profile measured with a dialysis technique. The NanoDis System showed clear superiority over the dialysis method and was able to accurately characterize the burst release from the capsules and furthermore discriminate between different all-trans retinoic acid nanoparticle formulations

High-Throughput Method for the Simultaneous Determination of Doxorubicin Metabolites in Rat Urine after Treatment with Different Drug Nanoformulations

Doxorubicin (DOX) is one of the most effective cytotoxic agents against malignant diseases. However, the clinical application of DOX is limited, due to dose-related toxicity. The development of DOX nanoformulations that significantly reduce its toxicity and affect the metabolic pathway of the drug requires improved methods for the quantitative determination of DOX metabolites with high specificity and sensitivity. This study aimed to develop a high-throughput method based on high-performance liquid chromatography with fluorescence detection (HPLC-FD) for the quantification of DOX and its metabolites in the urine of laboratory animals after treatment with different DOX nanoformulations. The developed method was validated by examining its specificity and selectivity, linearity, accuracy, precision, limit of detection, and limit of quantification. The DOX and its metabolites, doxorubicinol (DOXol) and doxorubicinone (DOXon), were successfully separated and quantified using idarubicin (IDA) as an internal standard (IS). The linearity was obtained over a concentration range of 0.05–1.6 μg/mL. The lowest limit of detection and limit of quantitation were obtained for DOXon at 5.0 ng/mL and 15.0 ng/mL, respectively. For each level of quality control (QC) samples, the inter- and intra-assay precision was less than 5%. The accuracy was in the range of 95.08–104.69%, indicating acceptable accuracy and precision of the developed method. The method was applied to the quantitative determination of DOX and its metabolites in the urine of rats treated by novel nanoformulated poly(lactic-co-glycolic acid) (DOX-PLGA), and compared with a commercially available DOX solution for injection (DOX-IN) and liposomal-DOX (DOX-MY)

A Straightforward Method to Produce Multi-Nanodrug Delivery Systems for Transdermal/Tympanic Patches Using Electrospinning and Electrospray

The delivery of drugs through the skin barrier at a predetermined rate is the aim of transdermal drug delivery systems (TDDSs). However, so far, TDDS has not fully attained its potential as an alternative to hypodermic injections and oral delivery. In this study, we presented a proof of concept of a dual drug-loaded patch made of nanoparticles (NPs) and ultrafine fibers fabricated by using one equipment, i.e., the electrospinning apparatus. Such NP/fiber systems can be useful to release drugs locally through the skin and the tympanic membrane. Briefly, dexamethasone (DEX)-loaded poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) fiber meshes were decorated with rhodamine (RHO)-loaded poly(lactic-co-glycolic acid) (PLGA) NPs, with RHO representing as a second drug model. By properly tuning the working parameters of electrospinning, DEX-loaded PHBHV fibers (i.e., by electrospinning mode) and RHO-loaded PLGA NPs (i.e., by electrospray mode) were successfully prepared and straightforwardly assembled to form a TDDS patch, which was characterized via Fourier transform infrared spectroscopy and dynamometry. The patch was then tested in vitro using human dermal fibroblasts (HDFs). The incorporation of DEX significantly reduced the fiber mesh stiffness. In vitro tests with showed that HDFs were viable for 8 days in contact with drug-loaded samples, and significant signs of cytotoxicity were not highlighted. Finally, thanks to a beaded structure of the fibers, a controlled release of DEX from the electrospun patch was obtained over 4 weeks, which may accomplish the therapeutic objective of a local, sustained and prolonged anti-inflammatory action of a TDDS, as is requested in chronic inflammatory conditions, and other pathological conditions, such as in sudden sensorineural hearing loss treatment

Screening of Surfactants for Improved Delivery of Antimicrobials and Poly-Lactic-co-Glycolic Acid Particles in Wound Tissue

Topical wound management is often a challenge due to the poor penetration of antimicrobials in wound tissue and across the biofilm matrix where bacteria are embedded. Surfactants have been used for decades to improve the stability of formulations, increase drug solubility, and enhance penetration. In this study, we screened different detergents with respect to their cytotoxicity and their ability to improve the penetration of poly-lactic-co-glycolic acid (PLGA) particles in wound tissue. Among the tested surfactants, Kolliphor SLS and Tween 80 increased the penetration of PLGA particles and had a limited cytotoxicity. Then, these surfactants were used to formulate PLGA particles loaded with the poorly water-soluble antibiotic ciprofloxacin. The antimicrobial efficacy of the formulations was tested in a wound infection model based on human ex vivo skin. We found that even though PLGA particles had the same antimicrobial efficiency than the particle-free drug formulation, thanks to their solubilizing and anti-biofilm properties, the surfactants remarkably improved the antimicrobial activity of ciprofloxacin with respect to the drug formulation in water. We conclude that the use of Tween 80 in antimicrobial formulations might be a safe and efficient option to improve the topical antimicrobial management of chronic wound infections