Curcumin powder from curcuma longa

Hyaluronic acid (HA) sodium salt from Streptococcus equi (cosmetic grade, high molecular HA-T grade, MW 1290 kDa, HA 94.9%, glucuronic acid 45.9%, and protein 0.027%) was purchased from Bloomage Freda Biopharm Corporation Limited (Jinan, China). Dimethyl sulfoxide (DMSO, 99.5% ACS, MW = 78.13 g/mol) was obtained from JSC EKOS-1 (Moscow, Russia). Curcumin powder from Curcuma longa (Turmeric) (MW = 368.38 g/mol, assay percentage 95.0%), phosphate-buffered saline (PBS, pH 7.4), and ethanol were obtained from Sigma-Aldrich (St. Louis, MO, USA). All chemicals were used without additional purification. Distilled water was obtained using distilling apparatus.
Hyaluronic acid (HA) sodium salt was chosen as a polymer basis for nonwoven nanofibrous materials obtained by the electrospinning technique. DMSO was used as a co-solvent. Curcumin of natural origin was used as the biologically active agent due to its reported unique set of antibacterial, antiviral, and anti-inflammatory properties. Spunlace (viscose:polyether 1:1) was obtained from LLC “Elegreen” (St. Petersburg, Russia) and used as the subsurface for nanofibers.

Dunino halloysite (HDU) extracted from the Polish mine in Dunino near Legnica (Poland), was used as raw material, after a purification process carried out by PTH Intermark, Gliwice (Poland). Unmodified Dunino halloysite was the reference material, also constituting the base for obtaining materials modified and intercalated with the drug. The following reagents were used to modify the surface of halloysite nanotubes: hydrogen peroxide approx. 30% p.a. by POCH Gliwice (Poland), potassium persulfate p.a. by POCH Gliwice (Poland), sodium hydroxide p.a. by STANLAB—Chemical Center, Lublin (Poland), sulfuric acid 98% p.a. by CHEMPUR, Piekary Śląskie (Poland), orthophosphoric acid 85% p. by CHEMPUR, Piekary Śląskie (Poland), and curcumin powder (from Curcuma longa, ≥65% (HPLC)) by Sigma-Aldrich (Poland). After the modification of the halloysite surface, the materials thus obtained were subjected to the intercalation process with the aminoglycoside antibiotic, i.e., gentamicin, in the form of a water-soluble sulphate powder from Pharma Cosmetic, Kraków (Poland).