Sodium alginate from

Chitosan chips derived from shrimp shell was purchased from Sigma Aldrich, average molecular weight, deacetylation degree, DD = 75–85%, and dynamic viscosity 200–800 cPoise (1% in aqueous solution 1% acetic acid, V/V) was used without further purification. Medium viscosity (viscosity of 2% solution 3500 cps at 25 1C) sodium alginate from the brown algae was obtained from Sigma Chemical. Medical grade ethanol was locally obtained and was distilled before it was used. The other reagents used were analytical grade namely, acetic acid, sodium lauryl sulfate, phenolphthalein, gallic acid hydrate, CaCO₃, and Folin-Ciocalteu reagent. Elastic adhesive bandage was obtained from Johnson & Johnson Ltd. Healing Ointment for lesion, acute and chronic wounds 30g, Cicasol ointment was bought from the pharmacy in Morocco.

Formulation of optimized bioink was 2.5% w/v alginate, 3.3% w/v mannitol, and 0.19% w/v calcium chloride in water. Sodium alginate from brown algae (W201502), calcium chloride (CaCl₂) (C8106) and D-mannitol (M4125) were purchased from Sigma Aldrich (St. Louis, MO, USA). Aqueous 0.67% w/v calcium chloride solution was prepared by dissolving CaCl₂ powder in distilled water and then sterilized with an autoclave. Alginate hydrogel was prepared by dissolving 3.5 % w/v of sodium alginate powder and 4.6% w/v of mannitol powder in distilled water and stirred for 5 h at room temperature (RT). Specific weight/volume values are determinants, as the density of bioprinted matrices is known to strongly influence the bioprinting process and the hydration state of the molecular components of the matrix, e.g., sugars or proteins [24 (link),49 (link),50 (link)]. The solution was sterilized in an autoclave for 20 min at 120 °C; just after temperature equilibration at RT, pre-crosslinking with calcium chloride solution in a ratio 25:10 = vol (Alginate):vol (calcium chloride) was performed [51 (link)].

Potato soluble starch (S-2360), α-amylase from porcine pancreas (A-3176, 5 MU), acarbose (A-8980), rat intestinal acetone powders (I-1360), 4-nitrophenyl-α-D-glucopyranoside (N-1377), Folin–Ciocalteu reagent (F-9252), sodium carbonate (Na₂CO₃) (S-2127), phloroglucinol (P-3502), gallic acid (G-7384), 2,2-diphenyl-1-picrylhydrazyl (DPPH) (D-9132), 3,5-dinitro-2-hydroxybenzoic acid (DNS) (D-0550), HEPES (4-(2-hydroxyethyl)-1-piperazine ethanesulphonic acid) buffer solution (H3375), fucoidan from F. vesiculosus (F8190), laminarin from L. digitate (L9634), sodium alginate from brown algae (w201502), fluorescein (F6377), and 2,2′-azobis (2-methylpropionamidine) dihydrochloride (AAPH, 4409914) were purchased from Sigma Aldrich Co. (St. Louis, MO, USA). Ethanol (absolute) was obtained from Desarrollo de Especialidades Químicas SA de CV (Monterrey, NL, Mexico). Distilled water was purchased from Garvy SA de CV (Monterrey, NL, Mexico); HPLC-grade water (4218-03) was obtained from J. T. Baker Co. (Center Valley, PA, USA). Formic acid 88% (A11-8P) and HPLC-grade methanol (A452-4) were purchased from Fisher Scientific Co. (Pittsburgh, PA, USA). EDTA (502-092) was purchased from LECO Co. (St. Joseph, MI, USA).