Polylysine polymers with antimicrobial and/or anticancer activity

A method, comprising:

• inhibiting a pathogen by contacting a cell of the pathogen with an antimicrobial polymer, wherein the antimicrobial polymer comprises a polylysine structure functionalized with a pendent guanidinium functional group, and wherein the polymer exhibits antimicrobial activity against a pathogen, and wherein the polymer comprises 70% or greater functionalization with the pendent guanidium functional group.

An anticancer chemical composition, comprising:

• a polymer comprising a molecular backbone covalently bonded to a pendent guanidinium functional group, wherein the molecular backbone comprises a polylysine structure, wherein the polymer exhibits anticancer activity, and wherein the polymer comprises 70% or greater functionalization with the pendent guanidium functional group.