Therapeutic applications of polymeric artificial cells

Key Points The concept of using 'artificial cells' — ultrathin polymer membrane microcapsules — to encapsulate materials such as transplanted cells, enzymes and absorbents was first put forward 40 years ago. Encapsulation was proposed to protect the enclosed materials from the external environment, thereby helping to prevent rejection by the immune system. The permeability, composition and configuration of the membrane can be varied using different types of materials, which allows for extensive variations in the properties and functions of the artificial cells. The artificial cells can also range in size from macro-dimensions of up to 2-mm diameter, through micron- and nano-dimensions to molecular dimensions. This review considers potential therapeutic applications of artificial cells, from cell encapsulation to treat disorders such as diabetes and neurological disorders, to enzyme replacement therapies and red-blood-cell substitutes. The key challenges for the future clinical development of such approaches are discussed. Polymeric artificial cells have the potential to be used for a wide variety of therapeutic applications, such as the encapsulation of transplanted islet cells to treat diabetic patients. Recent advances in biotechnology, molecular biology, nanotechnology and polymer chemistry are now opening up further exciting possibilities in this field. However, it is also recognized that there are several key obstacles to overcome in bringing such approaches into routine clinical use. This review describes the historical development and principles behind polymeric artificial cells, the present state of the art in their therapeutic application, and the promises and challenges for the future.