Fig 1.
Quantification of efficiency of aminoglycosides in alginate polymerization.
(a) TLC of commercial SA and Wakame extract show oligosaccharide profiles; the black arrow shows the flow direction of the mobile phase. (b) Optical density of commercial SA solution for different aminoglycosides; GS, KS, NS, SS, KDS, and TS. (c) Image of wells in a microtiter plate for commercial SA solution and different aminoglycosides; white turbidity led to higher optical density values. (d) Optical density of Wakame extract after addition of different aminoglycosides. (e) Image of wells in a microtiter plate for Wakame extract solution and different aminoglycosides. (f) Malleability and form fitting alginate biopolymer using KDS. Malleability and form fitting alginate biopolymer using KDS after kneading; twisted strands (left) and fingerprint capture (right). (g) Biopolymer made from Wakame extract using KDS.
Fig 2.
Melting of antimicrobial alginate polymer.
(a) Absorption spectra of the centrifugation supernatant after incubation of polymer in 1 M NaOH solution for 30 min at different temperatures. The peaks due to alginate and kanamycin disulfate are indicated by the solid and dotted black arrows respectively. (b) Integrated absorption (open black circle) as a function of temperature fits well to a sigmoidal function (red line) with a melting temperature of 34.7±2.5°C.
Fig 3.
Addition of aminoglycoside to sodium alginate and algae extract resulted in more thread-like polymers for neomycin sulfate and kanamycin disulfate, whereas other aminoglycosides showed more granular polymers.
Fig 4.
Scanning electron microscope (SEM) imaging of polymer.
(a) Images of wet polymer immediately after formation at low resolution (left panel) and high resolution (right panel) show threads and porous structures. (b) Images of dry polymer at low resolution (left panel) and high resolution (right panel) show a lack of porous structures observed in wet polymer.
Table 1.
Quantitative parameters of alginate polymer texture.
Fig 5.
Quantification of polymer formation for different aminoglycosides and prion protein-like growth model.
Different concentrations of aminoglycoside were added to (a) sodium alginate and (b) Wakame extract. The solution was centrifuged and dried to measure the weight of polymer.
Table 2.
Fit parameters for prion protein-like growth model of alginate polymer and dry weight, w (mg) of polymer per mg antibiotic.
Fig 6.
Antimicrobial activity of biopolymers against E. coli DH5α.
Circular zones of growth inhibition after antibiotics and polymers were placed in wells at the centers of LB plates.
Table 3.
Diameter (cm) of antimicrobial zone of inhibition by biopolymer against E.coli DH5α.
Fig 7.
Biocompatibility of alginate polymer.
Unstained (top panels) Fluorescent images (8 bit grayscale) of cell culture plates with biopolymer only (top left panel), COS-1 cells only (top middle panel), and COS-1 cells on biopolymer (top right panel). Staining with methylene blue increases the contrast (bottom panels). Methylene blue preferentially stains cell nuclei and provides more contrast. COS-1 cells grows on and attach to alginate polymer indicating biocompatibility.
Fig 8.
Chemical structures of aminoglycosides and mechanism of aminoglycoside-based alginate polymer.