A method for forming an antimicrobial coating on live tissue or a medical article, comprising: a) applying to a live tissue region or a surface of a medical article a non-metallic aqueous coating composition formed by combining: i) at least one silane of the formula R1Si(OR2)3 wherein R1 is a lower alkyl group, a phenyl group or a functional group including at least one of vinyl, acrylic, amino, m