Electrospun Solid Formulation of Anaerobic Gut Microbiome Bacteria
A model anaerobic bacterium strain from the gut microbiome (Clostridium butyricum) producing anti-inflammatory molecules was incorporated into polymer-free fibers of a water-soluble cyclodextrin matrix (HP-β-CD) using a promising scaled-up nanotechnology, high-speed electrospinning. A long-term stability study was also carried out on the bacteria in the fibers. Effect of storage conditions (temperature, presence of oxygen) and growth conditions on the bacterial viability in the fibers was investigated. The viability of the sporulated anaerobic bacteria in the fibers was maintained during 12 months of room temperature storage in the presence of oxygen. Direct compression was used to prepare tablets from the produced bacteria-containing fibers after milling (using an oscillating mill) and mixing with tableting excipients, making easy oral administration of the bacteria possible. No significant decrease was observed in bacterial viability following the processing of the fibers (milling and tableting). Access the full publication here
Conclusion
The present work demonstrated that high-speed electrospinning is capable of gently and continuously producing processable fibers that incorporate anaerobic bacteria from the gut microbiome. Bacteria-containing fibers with a water-soluble cyclodextrin matrix (HP-β-CD) were prepared with 300 mL/h feeding rate, corresponding to ~ 150-g solid product per hour. The viability of the electrospun sporulated anaerobic bacteria was preserved after 1 year of aerobic storage at ambient temperature, which makes a flexible drug storage possible. The bacteria-containing fibers were grindable by an oscillating mill, and the milled fibrous powder could be tableted by direct compression after mixing with tableting excipients. None of the processing steps (drying, milling, and tableting) caused significant reduction in bacterial viability. The developed oral dosage form of the anaerobic gut bacteria strain, Clostridium butyricum, shows that electrospinning is a promising formulation technology for potential microbiome therapeutics.Access the full publication here
Materials
Hydroxypropyl-beta-cyclodextrin (HP-β-CD) (Kleptose® HPB, MS = 0.62) was obtained from Roquette Pharma (Lestrem, France). Clostridium butyricum Prazmowski 1880 was obtained from the National Collection of Agricultural and Industrial Microorganisms (Budapest, Hungary). Clostridial nutrient medium (CNM), tryptic soy broth (TSB), and tryptic soy agar (TSA) were purchased from Merck KGaA (Darmstadt, Germany). Columbia blood agar plates were obtained from Biolab Zrt. (Budapest, Hungary). AnaeroGen™ 2.5 L Sachets (anaerobic gas generating sachets) were purchased from Diagon Ltd. (Budapest, Hungary). Microcrystalline cellulose (MCC) (Vivapur 200) was purchased from JRS Pharma (Rosenberg, Germany). Croscarmellose sodium (Ac-Di-Sol) was obtained from DuPont (Midland, MI, USA). Silicon dioxide (Aerosil 200) was acquired from Evonik Industries (Essen, Germany). Mannitol (Pearlitol 400 DC) was a kind gift from Roquette Pharma (Lestrem, France). Magnesium stearate was provided by Hungaropharma Ltd. (Budapest, Hungary). The water used in the experiments was from a Millipore Milli-Q ultrapure water system.