ABSTRACT
Various studies have investigated the interactions of polymeric materials with living cells, focusing on gene (or plasmid DNA) transfer, drug delivery systems (DDS), cell fusion, and cell immobilization onto biomaterials. For example, cationic poly(ethyleneimine) (PEI) and poly-l-lysine have been used to carry plasmid DNA into cells (Boussif et al. 1995, Chanana et al. 2005), and poly(ethylene glycol) (PEG) has been used to induce cell fusion in the preparation of hybridomas for the production of monoclonal antibodies (Honda et al. 1981). Recently, cell surface modication has attracted much attention in the biomedical elds. One example is the transplantation of islets of Langerhans, an insulin-releasing tissue isolated from the pancreas, to treat type 1 diabetes (Shapiro et al. 2000, Ryan et al. 2001). The islet surface is modied to increase blood compatibility or reduce their antigenic properties in order to enhance the clinical outcome (Miura et al. 2006, Cabric et al. 2007, Stabler et al. 2007, Teramura et al. 2007, 2008, 2010a,b, Teramura and Iwata 2008, 2009a,b, 2010a,b, Totani et al. 2008, Inui et al. 2010). Cell transplantation has attracted much attention as a promising method of treating serious diseases because various kinds of pluripotent stem cells, such as embryonic stem (ES) cells, induced pluripotent stem (iPS) cells, and mesenchymal stem cells, have been developed or identied, and their differentiation to functional cells has been extensively studied. The modication of the surface of these cells is expected to play an important role in their transplantation and reducing unfavorable recipient reactions, such as graft rejection and recurrence of an autoimmune reaction. In addition, modication of the surfaces of living cells with polymeric
10.1 Introduction .......................................................................................................................... 273 10.2 Cell Surface Modication with Synthetic Polymers ............................................................ 274
10.2.1 Covalent Bonding ..................................................................................................... 274 10.2.2 Hydrophobic Interaction ........................................................................................... 276 10.2.3 Electrostatic Interaction ............................................................................................ 276
10.3 Immobilization of Bioactive Substances on the Cell Surface .............................................. 277 10.3.1 Covalently Conjugated Polymers .............................................................................. 277 10.3.2 Amphiphilic Polymers .............................................................................................. 277
10.4 Biomedical Application of Cell Surface Modications ........................................................ 279 10.4.1 Islet Transplantation ................................................................................................. 279
10.4.1.1 Inhibition of Instant Blood-Mediated Inammatory Reactions ................ 279 10.4.1.2 Coverage of an Islet with Living Cells....................................................... 281
10.4.2 Cell Printing ............................................................................................................. 282 10.5 Summary .............................................................................................................................. 283 References ...................................................................................................................................... 283
materials allows for new opportunities in biomedical engineering and science because a variety of functional groups and bioactive substances can be introduced onto the cell surface, adding new functionality to the cell. These modications can be applied in various biomedical studies, such as development, regenerative medicine, and the immune system, some of which will be discussed in some detail.
