I think only polyphenylene is not suitable for biomedical applications due to very poor dispersity in aqueous media. You have to choose monomers with suitable functional moieties that can provide well defined polymer particles via conventional polymerization methods, are able to ensure tunable surface properties, acceptable dispersity in physiological conditions, biocompatibility, anchoring ability to any biomarkers or bioactive agents (drugs, proteins, carbohydrates etc).
How about poly(3,4-ethylenedioxythiophene) (PEDOT)? It is biocompatible and PEDOT:PSS (polystyrenesulfonate) dispersions in water are readily available commercially?