One aspect of the invention, pro-electronically polyoxazoline (electrophilically activated polyoxazoline, EL-POX) nucleophilic cross the activated-binding agent (nucleophilic cross-linking agent) and a biocompatible obtained by reacting, cross-covalently - relates to the combination, the polymer, and the activation to the pro-POX electronically includes m number of the electrophilic group (electrophilic groups); And the nucleophilic cross-binding agent and includes n nucleophilic groups (nucleophilic groups), Here, the m of the electrophilic group is capable of reacting with the n nucleophilic groups to form a covalent bond; Here, m = 2, n = 2 and m + n = 5, and; Here, at least one pendant electrophilic group (pendant electrophilic group) of the m electrophilic groups, and / or where, m = 3 and; And here, the EL-POX is the nucleophilic cross-includes an excess of the electrophilic group to the amount of the nucleophilic groups contained in the binder. The invention additionally, this cross-relates to a biocompatible medical article comprising the polymer, combined POX-. Biocompatible, cross-binds the POX- kit for the production of the polymer are also provided. The invention further provides a EL-POX tissue adhesive medical products comprising at least 1% of the dry matter of, and the EL-POX is, containing at least one pendant electrophilic groups, at least two electrophilic group It includes. The polymer according to the present invention, has superior implant (implant) and / or the sealing property (sealing characteristics).