SD 1: Evolution of the gels’ opacity measured at 600nm over-time during incubation with ammonium

sulfate solution.

SD 2: Macroscopic observation of the opacity of the different gels (a) and determination of gels’ weight

depending on the concentration of GS in the incubation solutions (b). Agarose was used as negative

control.

SD 3: Weight evolution of High-M alginate gels following o/n incubation in different conditions (TS:

tobramycin sulfate at 0.5 w:v %) normalized against pre-incubated gels. $ denotes significance

compared to CaCl2 condition. Both gentamycin sulfate (GS) and tobramycin sulfate (TS) are

responsible for similar gels shrinking as no significance was observed between those two groups (a).

Macroscopic appearance the gels and values of their diameters (in mm) after o/n incubation in the

difference conditions (b).