Nanoparticulate self-assembling

Self-assembled nanoparticulates comprise various kinds of polymeric, peptide-based, and lipoidal systems. The rationale for their pharmaceutical use is to incorporate the drug into the system and thereby modify its solubility or delivery. 

There are a large number of methods (Table 2) to prepare nanoparticulate systems. These depend to a large extent on the material (polymer, protein, metal, ceramic) that will form the basis of the carrier. One can, in essence, consider three approaches to their production (0 by comminution (in the case of solids, milling, and in the case of liquids, high pressure emulsification) (ii) molecular self-assembly, such as that occurs with polymeric surfactants to form polymeric micelles or with dendrons to form dendrimeric aggregates and (iii) precipitation from a good solvent as shown in Figure 6. 

Yoshida, T., Miyamoto, K., Hibi, N., Sugiura, T., Minoura, H., Schlettwein, D., Oekermann, T., Schneider, G., and Wbhrle, D. (1998) Self assembled growth of nanoparticulate porous ZnO thin film modified by 2,9,16,23-tetras ulfophthalocyanatozinc(II) by one-step electrodeposition. Chem. Lett., 7, 599-600. 

Surfactant adsorption at the surface As discussed in an earlier section, the adsorption of ionic surfactants can lead to charge development on the surface, and hence lead to stabilization of particulate dispersions. It has been shown recently by Adler et al. (10), that self-assembled surfactant layers at the particle surface can impart stability to nanoparticulate suspensions in extreme environments. It was proposed that the resistance to elastic deformation of the surface surfactant structures was the primary stabilization mechanism. 

D. I. Gittins, A. S. Susha, B. Sehoeler and F. Caruso, Dense Nanoparticulate Thin Films via Gold Nanoparticle Self-Assembly, Adv. Mater., 2002,14, 508-512. 

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