A fiber in fiber (FIF) bioreactor was designed and developed for cell culture to become a bioartificial liver device. The design consists of a conventional hollow fiber cartridge as a cell culture system with the addition of a second set of hollow fibers places within the lumens of the primary set. This arrangement provides three discrete spaces (compartments). A 3D CAD model of the device was developed and used to provide the suitable arrangement of these compartments. Internal and external diameters of the commercially available hollow fibers were studied and chosen. Two configurations of the device were developed and tested. Based on a 3D CAD model, two modules of the device were constructed and studied. Experimental evaluation of small scale FIF improved device prototype were constructed and results from studied quality assurance are also presented. The results showed that the developed bioartificial liver device has an excellent oxygen transfer rate which can improve the achievement of high density cell culture.