An implantable perfusion device , comprising: - a tubular transmission line with an inlet end , an outlet end and a flow restriction element located therebetween, whereby an inlet section of the transmission line is defined between the inlet end and the flow restriction element and whereby an outlet section of the transmission line is defined between the flow restriction element and the outlet end, - a perfusion chamber comprising a fluid entrance , a fluid exit and a chamber volume formed therebetween; the perfusion chamber containing a load of biologically active cells; characterized in that the fluid entrance comprises at least one first microchannel platelet and the fluid exit comprises at least one second microchannel platelet , each one of the microchannel platelets comprising at least one array of microchannels defining a fluid passage between respective external and internal platelet faces, the microchannels having an opening of 0.2 to 10 μm; each one of the microchannel platelets is sealingly connected to a circumferentially surrounding wall section of the perfusion chamber; wherein - the fluid entrance of the perfusion chamber is in fluid communication with the inlet section of the transmission line; and wherein - the flow restriction element is configured to establish a predetermined pressure excess in the inlet section versus the outlet section . - a tubular transmission line with an inlet end , an outlet end and a flow restriction element located therebetween, whereby an inlet section of the transmission line is defined between the inlet end and the flow restriction element and whereby an outlet section of the transmission line is defined between the flow restriction element and the outlet end, - a perfusion chamber comprising a fluid entrance , a fluid exit and a chamber volume formed therebetween; the perfusion chamber containing a load of biologically active cells; characterized in that the fluid entrance comprises at least one first microchannel platelet and the fluid exit comprises at least one second microchannel platelet , each one of the microchannel platelets comprising at least one array of microchannels defining a fluid passage between respective external and internal platelet faces, the microchannels having an opening of 0.2 to 10 μm; each one of the microchannel platelets is sealingly connected to a circumferentially surrounding wall section of the perfusion chamber; wherein the perfusion chamber containing a load of biologically active cells; characterized in that the fluid entrance comprises at least one first microchannel platelet and the fluid exit comprises at least one second microchannel platelet , each one of the microchannel platelets comprising at least one array of microchannels defining a fluid passage between respective external and internal platelet faces, the microchannels having an opening of 0.2 to 10 μm; each one of the microchannel platelets is sealingly connected to a circumferentially surrounding wall section of the perfusion chamber; - the fluid entrance of the perfusion chamber is in fluid communication with the inlet section of the transmission line; and wherein - the flow restriction element is configured to establish a predetermined pressure excess in the inlet section versus the outlet section . <EOS>