Ethanol

Polyester of natural origin—poly-3-hydroxybutyrate (PHB) was used in the work [49 (link),53 (link)]. PHB was used in the form of a finely dispersed powder (16F series, BIOMER, Schwalbach am Taunus, Germany), characterized by 59% of crystalline phase, 206 kDa of molecular weight, 1.248 g/cm³ of density (Figure 1a). A tetrapyrrole complex of natural origin—hemin (Hmi) was used in the work (Figure 1b) [54 (link)]. Hmi was obtained by the extraction method from the bovine blood (production by Aldrich Sigma, Saint Louis, MO, USA). Phosphate buffered saline (PBS) (Biolot, St. Petersburg, Russia); 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrasolium bromide (MTT) and Mowiol (Sigma-Aldrich, St. Louis, MO, USA); 96% ethanol (Chimmed, Moscow, Russia); Dulbecco’s modified Eagle’s medium (DMEM) (Gibco, Waltham, MA, USA); fetal bovine serum (FBS) (Gibco, Waltham, MA, USA); 0.9% saline (PanEco, Moscow, Russia); dimethyl sulfoxide (DMSO) (Amreso, Solon, OH, USA); 0.02% EDTA; 0.05% trypsin solutions (Gibco, Waltham, MA, USA); and gentamycin (PanEco, Moscow, Russia) were used for the experiments with cell cultures.

Total protein was assayed after Bradford with modifications^{24 (link),25 (link)} using a 96-well plate (Corning, United States) and a UV/VIS Infinite M200 PRO microplate reader (Tecan, Switzerland). The dye solution contained 0.03% Coomassie G-250 (LOBA Feinchemie, Austria), 5% ethanol, and 10% phosphoric acid (Chimmed, Russia). Bovine IgG (Reanal, Hungary) was used for the calibration curve.

Ruthenium (III) acetylacetonate (Acros Organics (Geel, Belgium), 97%), sulfuric acid (Σtec (Moscow, Russia), 95–98%), and benzyl ether (Sigma-Aldrich (St. Louis, MO, USA), 98%) were used as received. Levulinic acid (≥98%) was purchased from Merck KGaA, Darmstadt, Germany. Gamma-valerolactone (ReagentPlus^® (Moscow, Russia), 99%) was purchased from Sigma-Aldrich and used as received. Acetone (99.5%) and chloroform (99.8%) were purchased from Component-reactive (Moscow, Russia) and used without purification. Ethanol (96%) was purchased from Chimmed (Moscow, Russia) and used as received. PPP were synthesized as described elsewhere [37 (link)]. According to size exclusion chromatography (SEC), average molecular weight of the polymer was 62,704 g/mol with the polydispersity coefficient 2.9.