Bioartificial organs

Steps 7-10 involved the selection of animal models, islet isolation and the testing of the polymer microcapsules as bioartificial organs. This has been discussed elsewhere [61,62]. 

Maki T, Monaco AP, Million CJP, Solomon BA (1997) In Prokop A, Hunkeler D, Cher-rington A (eds) Bioartificial organs. New York Academy of Sciences, New York, NY... 

Ng, S.Y., Vandamme, T., Taylor, M.S., and Heller, J. (1997). Controlled drug release from self-catalyzed poly(ortho esters). Bioartificial Organs, 168-178. 

Membrane separation in the medical field has been included in a chapter focused on medical extracorporeal devices, which illustrates the use of membranes for separation of biological fluids and for preparation of bioartificial organs able to accomplish ex vivo biological transformation (Part headed Transformation ). 

Medical applications are among the most important in the membrane market, with hemodialysis, blood oxygenators, plasma separation and fractionation being the traditional areas of applications, while artificial and bioartificial organs and regenerative medicine represent emerging areas in the field. 

Membrane, with appropriate permeability characteristics, as well as, physicochemical properties, is used in bioartificial organs as selective barriers to compartmentalize isolated cells while allowing the transport of nutrients and metabolites to cells and the transport of catabohtes and specific metabolic products to blood. Moreover, the membrane avoids the contact between immune system components with xenogenic cells to prevent immunological response and rejection of xenograft. 

CytocompatibUity is a key issue for membrane in bioartificial organs. In this respect, the development of new materials with physicochemical properties that provide improved blood/cell compatibility is strictly related to the progress in this promising... 

Hunkier, D. Rehor, A. Canaple, L. Bernard, P. Renken, A. Rindisbacher, L. Angelova, N. Objectively assessing bioartificial organs. In Bioartificial Organs Tissue Sourcing Immunoisolation and Clinical Trials Hunkeler, D., Cherrington, A., Prokop, A., Rajotte, R., Eds. New York Academy of Sciences, November, 2001. 

In industrial (e.g. recombinant protein) and medical (e.g. bioartificial organ) fields 3D cultures can be used to improve the surface area/volume ratio compared with 2D cultures, which is a useful feature where cells are used as the machinery for biological production. Such approaches promote high cell yield and increased production of cellular or recombinant proteins. 

Prokop, A. (2001) Bioartificial Organs in the Twenty-First Century—Nanobiological Devices. Bioartificial Organs III Tissue Sourcing, Immunoisolation, and Clinical Trials. Ann. New York Acad. Sci., 944, 472-490. 

Perfusion MBRs have been introduced for the production of monoclonal antibodies. The mammalian cells that synthesize them are grown in the extracapillary space between the fibers in the module. Nutrients are supplied through the fibers, which also extract the metabolites continuously. The high cell concentrations between the fibers initiate high antibody harvests. These MBRs are also being investigated as an alternative concept for bioartificial organs such as liver and pancreas. 

Hunkeler D, Prokop A, Cherrington A, Rajotte R, Sefton M. Bioartificial Organs II. Technology, Medicine and Materials. Annals of the New York Academy of Sciences 1999 875. 

MBR and perfusion MBR are also looked upon as an attractive concept in the development of bioartificial organs (liver, pancreas). There is an urgent need today for the development of such bioartificial organs, as there is critical shortage of organ donors. One of... 

Figure 4.6. The two MBR types for bioartificial organs, a separate plasma and cells configuration. 1 plasma or culture medium feed, 2 oxygen feed, 3 oxygen exit, 4 plasma or culture medium exit, 5 living cells and medium, b perfusion MBR, 6 hollow fibers for oxygen feed, 7 external shell, 8 spirally wound polyester film, 9 anchored cells in a 3D matrix. Adapted from Legallais et al. [4.41].

Whole-cell, hollow-fiber MBR are still under development. Despite their significant potential they have, so far, found only limited application for biochemicals production. One of the reasons is that cleaning of the hollow-fiber membranes is difficult, especially when whole-cell biocatalysts are immobilized in the small fibers. The mass transfer between the nutrients and cells has also to be taken into consideration and enhanced. Immobilizing the biocatalysts in porous beads, instead of directly on the membrane, may tend to avoid some of these problems, and to simplify membrane cleaning. The concept of using MBR as bioartificial organs is technically very attractive the various MBR under development, however, must still be validated with clinical results. One can expect, however, that their development will follow the success of artificial kidneys, which are currently employed worldwide. 

Domish M, Kaplan D, Skaugrud O (2001) Bioartificial organs III tissue sourcing, immu-noisolation, and clinical trials. Ann NY Acad Sci 944 388... 

Our screening and testing of multicomponent capsules/beads is incomplete. However, it offers a novel approach for the material selection for immobilization devices, which permits the simultaneous control of permeability, mechanical stability, and compatibility. The alternative multicomponent systems presented herein offer new possibilities for biomaterials, particularly those employed in bioartificial organs. 

Examples of medical textiles used in extracorporeal medical devices include the use of hollow fibres and membranes (made om polyester, polypropylene, silicone, viscose) for production of bioartificial organs, such as the kidneys, liver and lungs. 

Zhou D., Kintsourashvili E., Mamujee S., Vacek 1., Sun A.M., Bioartificial pancreas Altemative supply of insulin-secreting cells, in Bioartificial organs II. Technology, medicine materials, Eds. Hunkeler D., Prokop A., Cherington A.D., Rajotte R. V., and Sefton M., Annals of the New York Academy of Sciences, New York Arm. NY. Acad. Sci. 875, 1999, pp. 208-218. 

Popat KC, Mor G, Grimes CA, Desai TA (2004) Surface modification of nanoporous alumina surfaces with poly(ethylene glycol). Langmuir 20(19) 8035-8041 Pope EA, Braun K, Peterson C (1997) Bioartificial organs I silica gel encapsulated pancreatic islets for the treatment of diabetes mellitus. J Sol-Gel Sci Tech 8(l-3) 635-639 Sakai S, Ono T, Ijima H, Kawakami K (2003) Proliferation and insulin secretion function of mouse insulinoma cells encapsulated in alginate/sol-gel synthesized aminopropyl-silicate/alginate microcapsule. J Sol-Gel Sci Tech 28(2) 267-272... 

Hundreds of bioengineers are working around the world, and they have created a wide variety of applications using cell and tissue engineering research. Among the most promising applications are cell matrices and bioartificial organ assistance devices. 

Bioartificial Organs. One of the major areas of research in tissue engineering is the creation of machines that assist organs damaged by disease or injury. Made from a combination of synthetic and organic materials, these machines are sometimes called bioartificial devices. 

The inertness of polymers could prove very beneficial if they possessed certain bulk properties such as electrical or magnetic susceptibility that one could exploit. We believe that the electroactive polymers, namely electronically and ionically conducting polymers, piezoelectrics, and electrets, by virtue of their susceptibility to either mechanical or electromagnetic or thermal or optical phenomena, could be utilized to interface between the external world and the physiological environment and could prove quite beneficial in eliciting the desired cellular response. These polymers represents a new modality in the development of interactive scaffolds for tissue stimulation, tissue regeneration, and the development of bioartificial organs. 

Pope E.J.A., Braun K., Petersen C.M. Bioartificial organs. I Sihca gel encapsulated pancreatic islets for the treatment of diabetes meUitus. J. Sol-Gel Sci. Technol. 1997 8 635-639 Reetz M.T., Zonta A., Simpelkamp J., Rufinska A., Tesche B. Characterization of hydrophobic sol-gel materials containing entrapped lipase. J. Sol-Gel Sci. Technol. 1996 7 35-43 Reisfeld R. Spectroscopy and application of molecules in glasses. J. Non-Cryst. Sol. 1990 121 254-266... 

Sakai S., Ono T., Ijima H., Kawakami K. Aminopropyl-silicate membrane for microcapsule-shaped bioartificial organs control of molecular permeability. J. Membr. Sd. 2002 202 73-80 Sakai S., Ono T., Ijima H., Kawakami K. Permeability of alginate/sol-gel s)mthesized aminopropyl-silicate/alginate membrane templated by calcium-alginate gel. J. Membr. Sci. 2002 205 183-189... 

This chapter will review recent advances in cell encapsulation from material science, technological and tissue-related perspectives. Cell coating, microencapsulation devices and bioartificial organs will be discussed with the artificial pancreas and treatment of diabetes used as a case study denominator throughout the review. 

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