The invention is directed to a tissue-adhesive polymer blend comprising a bioresorbable carrier polymer and a bioresorbable synthetic tissue-reactive polymer as well as to a tissue-adhesive device for sealing dura mater comprising said tissue-adhesive polymer blend. The carrier polymer may be a synthetic carrier polymer comprising polyesters, polyethers, polyhydroxyacids, polylactones, polyetheresters, polycarbonates, polydioxanes, polyanhydrides, polyurethanes, polyester(ether)urethanes, polyurethane urea, polyamides, polyesteramides, poly-orthoesters, polyaminoacids, polyphosphonates, polyphosphazenes and combinations thereof.