Fig. 3: Preparation and in vitro antimicrobial behavior of LGG@Ga-poly.

a Schematic illustration of the preparation of biohybrid LGG@Ga-poly. b Screening for different ions with antimicrobial properties evaluated on E. coli, S. aureus, B. subtilis, and LGG (n = 5 samples). c Number of E. coli colonies after treatment with Ga3+ or Ga3+ coordinated with different polyphenols (n = 3 samples). d Zeta potentials of different materials, including LGG, LGG coated with chitosan (LGG-poly), LGG-poly coated with Ga-EGCG (LGG@Ga), and LGG@Ga-poly (n = 3 samples). e TEM-assisted element mapping of LGG@Ga-poly (C element; O element; Ga element). The scale bars are 1 μm. Experiments were performed three times. f Growth curves of LGG, LGG@poly, and LGG@Ga-poly in MRS medium (n = 5 samples). g LGG viability in the simulated gastric fluid (SGF) treated with different materials, including LGG, LGG@poly, and LGG@Ga-poly (n = 3 samples). h Ga3+ release in simulated colonic fluid (SCF) of LGG@Ga and LGG@Ga-poly (n = 3 samples). i The growth of F. nucleatum after different treatments (n = 3 samples). j The growth of E. coli after treatment by LGG@Ga-poly or LGG@Ga-poly plus Fe3+ (n = 6 samples). k Penetration of FITC or LGG@FITC into PDAC 3D cell spheres. The cell spheres were pre-infected with Mcherry-expressing E. coli. Mcherry-field images, FITC-field images, and merged images are shown. The scale bars are 50 μm. Experiments were repeated three times. l Concentration of LPS in cell spheres treated with free Ga3+ or LGG@Ga-poly (n = 3 samples). Significance between two groups was calculated using two-tailed Student’s t-tests (h and l) or one-way ANOVA with Tukey post hoc test (b, c, g, i, and j). Data are means ± sem. n.s. means no significance. Source data are provided as a Source Data file.