The present invention provides a polymer product and a method for preparing the polymer product comprising electrospinning from a dope solution comprising at least one polymer and at least one cross-linking agent to prepare and/or fabricate the polymer product. In certain embodiments, the cross-linking agent comprises at least one catecholamine or at least one polyphenol, wherein the method comprises (i) electrospinning the biocompatible polymer product using a dope solution comprising a polymer and at least one catecholamine or at least one polyphenol and (ii) exposing the polymer product to at least one gaseous alkaline reagent. The dope solutions and polymer products of the invention can further include antimicrobial agents, metal ions, and other substances.