Xanthan

In previous work, a xanthan-degrading strain named Microbacterium sp. XT11 (China Center for Type Culture Collection CCTCC AB2016011) was isolated in the author’s laboratory [14 ]. In this work, the gene encoding the endotype xanthanase MiXen, and the gene fragment encoding its catalytic domain (MiXen-CD), were cloned from genomic DNA of Microbacterium sp. XT11. Escherichia coli DH10B and E. coli BL21 (DE3) were used in gene cloning experiments and for the expression of recombinant enzymes, respectively.
Microbacterium sp. XT11 was cultivated at 30 °C in xanthan medium (0.5 g/L glucose, 3 g/L yeast extract, 3 g/L xanthan (purchased from sigma), 0.8 g/L NaCl, 0.05 g/L K₂HPO₄, 0.70 g/L KNO₃ and 0.025 g/L MgSO₄·7H₂O, pH 7.0). E. coli strains were grown at 37 °C in Luria–Bertani (LB) medium (5.0 g/L yeast extract, 10 g/L sodium chloride and 10 g/L tryptone, pH 7.0) [14 ].

Docetaxel powder (DTX) and lidocaine hydrochloride (LDC) were donated by Cristália Prod. Quim. Farm. Ltd.a (Itapira, SP, Brazil). Docetaxel trihydrate 20 mg mL⁻¹ (DTX_T-HYD) was kindly provided by Blau Pharmaceutica S.A. (Cotia, SP, Brazil). 18F-fluorodeoxyglucose (¹⁸F-[FDG]) was a gift from Cyclobras Ind. Com. Lab. Services Ltda (São Paulo, SP, Brazil). Pluronic F-68 (P68), Myristyl myristate (MM), Miglyol 812^® (MG), chitosan (CHT), xanthan (XAN), DMEM medium, fetal bovine serum and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) were supplied by Sigma-Aldrich (St. Louis, MO, USA). Deionized water (18 MΩ) was obtained from an Elga USF Maxima ultra-pure water purifier. Phosphate-buffered saline (PBS), dimethyl sulfoxide and ultrapure water are from Laborclin (Pinhais, PR, Brazil), Vetec (São Paulo, SP, Brazil) and Barnstead™, Thermo Scientific (Thermo Scientific, Waltham, MA, USA), respectively. Murine fibroblasts (NIH-3T3) and murine melanoma (B16-F10) cells were purchased from American type culture collection (ATCC, Manassas, VA, USA). Human melanoma (SK-MEL-103) and human keratinocytes (HaCaT) cell line were purchased from Memorial Sloan Kettering cancer center (New York, NY, USA and CLS cell lines Service GmbH (Heidelberg, Germany), respectively. All other reagents were of analytical grade.

Gelatin (porcine, type A) was generously provided by Medana Pharma (Sieradz, Poland), Aquacoat CPD^® (FMC Biopolymer, Philadelphia, PA, USA), a 30% aqueous pseudolatex dispersion of cellulose acetate phthalate (CAP) and cellulose acetate propionate (CAP 482-0.5), cellulose acetate butyrate (CAB 381-0.5) (Eastman Chemical, Kingsport, TN, USA), hypromellose phthalate (HPMCP(HP-55), hypromellose acetate succinate (HPMCAS) (Aqoat AS-MF and AS-HF, Shin-Etsu, Tokyo, Japan) were gifts from IMCD Polska (Warsaw, Poland). Eudragit L30 D-55, Eudragit L100, and Acryl Eze II (Evonik, Essen, Germany) were obtained from Evonik. Opadry Enteric (Colorcon, Budapest, Hungary) was provided by Colorcon. Aquarius Control ENA (Ashland, Covington, KY, USA) was received from Ashland. Glycerol (99.5%) was purchased from Chempur (Piekary Śląskie, Poland), polyethylene glycol (PEG-400), sorbitol, ί-carrageenan, gellan, and xanthan were purchased from Sigma Aldrich (Saint Louis, MO, USA). The compositions of certain complex products are specified further in Table 1.