The invention in the various aspects provides nanogel compositions that are safe for topical, local, and/or systemic delivery, and which can be targeted to select tissues or cells, including pathogens. In some embodiments, conjugation of antibiotics to the nanogel surface, and in particular antibiotics that disrupt outer membranes of Gram negative bacteria or antibiotics that inhibit cell wall synthesis, provide for highly effective targeting and killing of bacterial pathogens, including drug-resistant bacteria.