Dendrimers in Gene Transfection D. G. Shcharbin 1 *, B. Klajnert 2 , and M. Bryszewska 2 1 Institute of Biophysics and Cell Engineering, National Academy of Sciences of Belarus, ul. Akademicheskaya 27, 220072 Minsk, Belarus; E-mail: d.shcharbin@mail.ru 2 Department of General Biophysics, University of Lodz, Banacha 12/16, Lodz 90-237, Poland; E-mail: marbrys@biol.uni.lodz.pl * To whom correspondence should be addressed. Abstract—Dendrimers are a new class of nanocomposite materials. They are branching polymers whose structure is formed by monomeric subunit branches diverging to all sides from a central nucleus. The type of nucleus, attached monomers, and functional groups can be chosen during synthesis, which produces dendrimers of definite size, shape, density, polarity, branch mobility, and solubility. This review deals with problems of dendrimer molecular structures and capability of in vitro, in vivo, ex vivo, and in situ transfection of genetic material. Advantages and shortcomings of different types of dendrimers in this respect are discussed. DOI: 10.1134/S000629790910002? Key words: dendrimer, complex, transfection, gene, DNA, RNA Chemistry and technology of polymers traditionally focused on linear polymers. However, at the end of 1980s a new type of polymeric materials called dendrimers (from Greek “dendron” – tree and “meros” – branch) was obtained in groups of Tomalia, Newkome, and Vogtle [1-5]. Dendrimers are globular in shape with topological structure formed by monomeric subunit branches diverging to all sides from the central nucleus (Fig. 1) [6]. Properties of synthesized macromolecules can be precisely assigned in advance by choosing appropriate monomers and functional groups [2-8]. The following features can be distinguished in dendrimers: (i) multivalent surface containing numerous potentially active sites, (ii) envelopes surrounding the nucleus, and (iii) the nucleus with attached dendrons. Fig. 1. Dendrimer structure. 1) Nucleus 2) Internal cavities 3) Surface groups