Propylene carbonate

Sodium alginate powder (lot number: 71238) was purchased from Sigma Aldrich (Steinheim, Germany). Fine calcium carbonate powder (Ph. Eur. grade) was acquired from Magnesia GmbH (Lüneburg, Germany). CO₂ was supplied by AGA Gas GmbH (Hamburg, Germany). Ethanol, IPA, DMF, acetonitrile and propylene carbonate purchased from Carl Roth GmbH (Karlsruhe, Germany); glycerol from Merck (Darmstadt, Germany); acetone, MEK, DEK from Bernd Kraft (Duisburg, Germany); and 1-butanol, DMSO, furfuryl alcohol, ethylene glycol, propylene glycol and 1,4-dioxane were purchased from Sigma Aldrich (Steinheim, Germany). The water used throughout the study was deionized (pH 6.5–7.0).

NFC was purchased from University of Maine (Orono, ME, USA) as an aqueous fibril suspension with a solid content of about 3 wt %. Chemical modification of NFC was performed with acetic anhydride (AA, ≥99% purity, Carl Roth, Karlsruhe, Germany) and (2-dodecen-1-yl)succinic anhydride (DDSA, 95% purity, Sigma-Aldrich, St. Louis, MO, USA) with pyridine (anhydrous, 99.8% purity, Sigma-Aldrich, St. Louis, MO, USA) and 4-(dimethylamino)pyridine (4-DMAP, ≥99% purity, Carl Roth, Karlsruhe, Germany) as catalysts. Solvents used were acetone (≥99.5% purity), propylene carbonate (≥99.7% purity), ethanol (≥99.8% purity, denatured), and n-hexane (≥99% purity), all purchased from Carl Roth (Karlsruhe, Germany). For sedimentation tests and wood coating, a commercial linseed oil varnish (Tiger Leinölfirnis, Tiger Coatings GmbH and Co. KG., Wels, Austria) was used along with the thinner Terptin Extra from the same manufacturer. The thinner used is a mixture of solvents, mainly hydrotreated heavy naphtha (petroleum) and 2-methylpropan-1-ol.

CorA was produced by the CRO Acies Bio (Ljubljana, Slovenia) using the natural producer strain Corallococcus coralloides B035 [28 (link),38 (link)], or the Helmholtz Centre for Infection Research, Department of Microbial Drugs using the heterologous producer strain Myxococcus xanthus carrying the CorA biosynthesis gene cluster [39 (link)]. The CorA batches always exceeded a purity of 92%-96% as determined via ¹H-NMR (S1 Fig). CorA was formulated in a 1:1 solution of polyethylene glycol 400 (PEG400; Carl Roth GmbH + Co. KG, Karlsruhe, Germany) and phosphate buffered saline, pH 7.4 (PBS; Gibco, ThermoFisher Scientific GmbH, Dreieich, Germany) for intraperitoneal (IP) administration. For oral (PO) administration, a formulation comprising CorA (20% weight), propylene carbonate (30% weight, ≥ 99.7%, Carl Roth GmbH + Co. KG), and Syloid XDP 3050 (50% weight, Grace GmbH, Worms, Germany) suspended in PBS was administered.