We present a DNA-containing polymeric nanocontainer using the self-assembled superstructure of amphiphilic block copolymers in aqueous solutions. To demonstrate that DNA translocation is possible across a completely synthetic block copolymer membrane, we have used a phage transfection strategy as a DNA-transfer model system. For this purpose the bacterial channel forming protein LamB was reconstituted in ABA-triblock copolymer vesicles. The outer membrane protein LamB is a specific transporter for maltodextrins but also serves as a receptor for lambda phage to trigger the ejection of lambda phage DNA. We demonstrate that the functionality of the LamB protein is fully preserved despite the artificial surrounding. This leads to a type of polymeric vehicle for DNA that could be useful for gene therapy.