The present invention generally relates to implantable devices for producing insulin in diabetic animals and to methods of making same. Some embodiments include amphiphilic biomembranes for use in biological applications (e.g., as an alternative and/or supplemental insulin source). Some embodiments also include live insulin-producing cells contained within one or more amphiphilic membranes so as to prevent or diminish an immuno-response and/or rejection by the host.