Sodium alginate

The edible films were prepared by cold-casting using micromolding. In addition, a flat mold was used as control (without microstructure). The preparation of the films was made using non-mammalian components as described by Acevedo et al. [2 (link)] with minimal modifications. This formulation was based on a composite preparation by combining four components with well-defined properties related to bioactivity (salmon gelatin), crosslinking (calcium alginate), gelling (agarose), and plasticizing (glycerol). Salmon gelatin is a functional protein containing RGD-sequences allowing cell adhesion and proliferation [12 (link),13 (link),14 (link)]. Briefly, a solution composed by salmon gelatin 1.2% (obtained as described by Díaz et al. [23 (link)]), sodium alginate 1.2% w/v (Loba Chemie Pvt. Ltd., Mumbai, India), agarose 0.2% w/v (Loba Chemie Pvt. Ltd., Mumbai, India), and glycerol 1.0% (Merck, Darmstadt, Germany) was prepared at 50 °C with gentle agitation for 4 h. The solution was poured into the mold, regulating the volume in order to obtain 4 mm of height. The solutions were kept for 3 days at 10 °C to allow water evaporation, obtaining low moisture content films.
Prior to cell seeding, the films were soaked in CaCl₂ solution (70 mM) for 1 h to crosslink the alginate fraction and obtain a non-water-soluble material [8 (link),24 (link)].

The assay was carried out with aqueous solutions of cadmium. This solution was placed together with the alginate beads in Florence flasks. Every 10 minutes a sample of the aqueous solution was taken (10 mL approximately) with a glass pipette, and each sample was placed in a test tube. The concentration of metal was measured by aspiration atomic absorption spectrophotometer.
To make the control beads, the procedure described in a previous work was followed
⁷ . Briefly, 2 grams of sodium alginate (Loba Chemie, high density) were dissolved in 200 mL of ultra-pure water to obtain a homogeneous mixture, adjusting the pH between 7.8–8.0. pH was adjusted by addition of 0.1 molar sodium hydroxide or 0.1 molar hydrochloric acid, in sodium alginate paste (homogeneous mixture). One drop at a time was slowly poured into a 1% w/v calcium chloride solution with constant stirring.
For the immobilization of
Chlorella sp. in alginate beads, liquid cultures were used. The volume of culture to be used was established to reach a concentration of 25 X 10
⁶ cells mL per each mL of alginate. For the preparation of the beads, 2 g of sodium alginate were dissolved in microalgae culture, as above.

Tomato fruits (Solanum lycopersicum) were purchased from an outlet selling Egyptian Ministry of Agriculture products in Giza Governorate, Egypt. In this study, tomatoes grown in Egyptian Ministry of Agriculture farms and harvested in October 2022 were used to be identical in cultivation. Probiotics, Lactobacillus acidophilus (LA-5) and Bifidobacterium bifidum (Bb-12), were obtained from Chr. Hansen`s Laboratory, Copenhagen, Denmark. Sodium alginate (medium viscosity) was purchased from Loba Chemie, Pvt Ltd—Mumbai, India. 2,2-Dipheny l-1-picryl hydrazyl (DPPH) and Trolox were purchased from Sigma-Aldrich Chemical Co., (St. Louis, USA). All of the solvents, chemicals, and culture media used in this study are of analytical grade.

Captopril was supplied by EIPICO Pharmaceutical Industries Co., Cairo, Egypt. Capoten^® tablets (batch no. 74427C) were purchased from GlaxoSmithKline (GSK) Beecham, Cairo, Egypt. Gelatin powder Type A was purchased from Alpha Chemika, Mumbai, India. Sodium alginate was purchased from Loba Chemie LTD., Mumbai, India. Glycerin, Tween 80, propranolol (IS), and fluorenylmethoxycarbonyl chloride (FMOC-Cl) were from Sigma-Aldrich (St. Louis, MO, USA). Moreover, polyvinyl alcohol was supplied by BDH Chemicals, Poole, England. Sucralose was provided by Asin Co., Mirkow, Poland.

Sodium selenite (Na₂SeO₃), as a precursor of Selenium nanorods (Se-NRs), was purchased from Sigma Aldrich (USA). Green fresh leaves of Aloe vera with similar color, shapes, and out of the physical destruction were obtained from a local market (Giza, Egypt). Sodium alginate and guar gum were obtained from Loba Chemie, Pvt Ltd—Mumbai, India. Fresh milk was provided by the Faculty of Agriculture, Cairo University, Egypt.

Vardenafil HCl trihydrate (Batch number UT2210202) was given by El-Obour Modern Pharmaceutical Industries Co., Kaliobeya, Egypt. Sodium alginate (low viscosity grade) and glycerol were supplied by Loba Chemie Ltd., Mumbai, India. Polyvinyl pyrrolidone K30 and methylcellulose were purchased from Sigma Aldrich (St. Louis, MO, USA). Polyvinyl alcohol (molecular weight: 14,000) was purchased from BDH Chemicals Ltd., Poole, England. Sorbitol was supplied by Modernist Pantry, Eliot, ME, USA; acesulfame potassium was obtained from Sanofi Ingredients, Shanghai, China; sucralose was supplied by Asin Co., Mirkow, Poland.