Cell Microencapsulation

The advancement of science is ever more contingent upon the interaction of experts vast amount of scientific information being gathered every day that exceeds the ability of any one scientist to acquire. As an illustration of the frantic pace of scientific disc- more acute in the case of scientific fields at the interface of different and seemingly distant areas of study. Amidst these, the field of cell encapsulation brings together an array of diverse disciplines such as molecular biology and biopolymers, gene therapy and inorganic membranes, stem cell biology and physicochemistry, immunology and nanotechnology. Clearly, such range of topics is too broad for any individual scientist the state-of-the-art in the field of cell encapsulation. At the core of this technology, there is an interaction of physicochemical and biological elements forming three distinct layers of complexity. First, the chemistry of the biopolymer dictates the degree of protein adsorption, vascularization, tox- ity and biocompatibility of the microcapsules. Advances in biopolymer science are providing solutions to overcome existing challenges and to improve microcapsules as delivery vehicles. Second, the choice of cells, and more precisely the plethora of in determining the immune response elicited by the host to implanted microcapsules.

This volume provides a unique forum to review cell microencapsulation in a broad sense by exploring various cell types that have been encapsulated for different purposes, different approaches and devices used for microencapsulation, the biomaterials used in cell microencapsulation, the challenges to the technology, and the current status of its application in different clinical situations. This book is divided in five sections: Section I is an introductory part that discusses historical developments of the technology and its current challenges, as well as the various applications of cell microencapsulation; Section II discusses the main approaches and devices currently used in cell microencapsulation; Section III presents an overview of the various polymeric materials currently in use for cell microencapsulation and the enabling technologies to either monitor or enhance encapsulated cell function; Section IV gives specific examples of the methods used to encapsulate various cell types; and Section V provides an overview of the different clinical situations in which cell microencapsulation has been applied. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Thorough and practical, Cell Microencapsulation: Methods and Protocols is a valuable reference for researchers, engineers, clinicians, and other healthcare professionals, as well as food technologists who will find detailed descriptions of methods for the microencapsulation of specific cell types and their current of potential clinical and industrial applications. This volume also includes detailed information about the design and manufacture of different devices including large-scale production devices for use in cell microencapsulation.

This volume provides a unique forum to review cell microencapsulation in a broad sense by exploring various cell types that have been encapsulated for different purposes, different approaches and devices used for microencapsulation, the biomaterials used in cell microencapsulation, the challenges to the technology, and the current status of its application in different clinical situations. This book is divided in five sections: Section I is an introductory part that discusses historical developments of the technology and its current challenges, as well as the various applications of cell microencapsulation; Section II discusses the main approaches and devices currently used in cell microencapsulation; Section III presents an overview of the various polymeric materials currently in use for cell microencapsulation and the enabling technologies to either monitor or enhance encapsulated cell function; Section IV gives specific examples of the methods used to encapsulate various cell types; and Section V provides an overview of the different clinical situations in which cell microencapsulation has been applied. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Thorough and practical, Cell Microencapsulation: Methods and Protocols is a valuable reference for researchers, engineers, clinicians, and other healthcare professionals, as well as food technologists who will find detailed descriptions of methods for the microencapsulation of specific cell types and their current of potential clinical and industrial applications. This volume also includes detailed information about the design and manufacture of different devices including large-scale production devices for use in cell microencapsulation.

The concept of using encapsulation for the immunoprotection of transplanted cells was introduced for the first time in the 1960s. "[Microencapsulated cells] might be protected from destruction and from partici pation in immunological processes, while the enclosing membrane would be permeable to small molecules of specific cellular product which could then enter the general extracellular compartment of the recipient. For instance, encapsulated endocrine cells might survive and maintain an effective supply of hormone." (Chang, Ph. D. Thesis, McGill University, 1965; Chang et aI., Can J Physiol PharmacoI44:115-128, 1966). We asked Connaught Laboratories, Ltd., in Toronto to put this concept into practice. In 1980, Lim and Sun from Connaught Laboratories reported on the successful implantation of poly-I-Iysine-alginate encapsu lated rat islets into a foreign host. [Lim and Sun, Science 210:908-909, 1980]. Now many groups around the world are making tremendous progress in the encapsulation of a multitude of cell types. Kiihtreiber, Lanza, and Chick have invited many cell encapsulation groups from around the world to contribute to this book. The result is a very useful reference book in this rapidly growing area. With so many excellent au thors describing in detail the different areas of cell encapsulation, my role here will be to briefly discuss a few points.

of McGill University of Montreal, Canada, who talks about artifi cial cells prepared from semipermeable microcapsules. Also illustrative of this method is a contribution on microencapsulated pesticides by C. B. Desavigny and E. E. Ivy of Pennwalt Corporation. Another method of polymerization in situ is micro encapsulation by vapor deposition, the subject of W. M. Jayne of Union Carbide Corporation. The more mechanical methods of microencapsulation are represented by two techniques, one involving a fluidized bed the other involving mainly a centrifugal method. The fluidized bed method is covered in a paper by H. Hall and T. M. Hinkes of the Wisconsin Alumini Research Foundation. The centrifugal and other related methods are treated by Mr. J. E. Goodwin and Mr. Sommerville of the Southwest Research Institute of San Antoni~ Texas. Dr. G. Baxter of Moore Business Forms, studied capsules made by mechanical methods as well as by chemical methods. Mr. Russell G. Arnold of the Bureau of Veteranary Medicine of the Food and Drug Administration draws our attention to the procedures to be used for securing approval of a new animal drug application for the marketing of microencapsulated products. And last but not least, we have a contribution by Mr. G. O. Fanger on "Micro encapsulation a Brief History and Introduction, whose title speaks for itself.

Bioencapsulation (or microencapsulation) of cells and their implantation into a body of immunoprotected cells allows researchers to revive a missing or defective function in the cells. Microencapsulated cells have reached the clinic where they have been shown to be safe and efficacious in numerous clinical trials. Cell types that have been encapsulated for therapeutic purposes include hybridomas, islet cells, "platform" cell lines e.g. HEK293 and CHO cells as well as an increasing focus on the encapsulation of stem cells. This e-book explains the different methods used for achieving cell bioencapsulation based on different polymers e.g. alginate, cellulose sulphate and agarose. Other chapters in this book subsequently describe the use of cell encapsulation in cancer therapy to improve on existing chemotherapies by reducing doses and thus side effects while increasing efficacy for long term in vivo production of (i) tumoricidal or virus neutralising antibodies, (ii) insulin to achieve a self regulating treatment for diabetes and (iii) neuron nurturing factors to treat CNS diseases such as epilepsy, disorders like Parkinson's disease, Alzheimer, Amyotrophic lateral sclerosis, Huntington's disease and pathologies caused by trauma and/or ischemic processes. The book also includes a chapter reviewing the genetic engineering of cells to allow controlled production of biotherapeutics from encapsulated cells. This is a unique and timely book which brings together contributions from some of the leading researchers in the field of cell encapsulation. Interested readers are provided an overview of the exciting developments and clinical experiences of researchers with cell bioencapsulation.