Pellicular solid supports

The original pin support was poly(acrylic acid) grafted onto inert polyethylene, where the carboxylic acid moieties were capped with mono Boc-protected ethyl-enediamine [79]. PS and the extremely hydrophilic polyhydroxyethyl methacrylate and poly(methacrylic add/dimethylacrylamide) were also grafted on [81]. The last grafted support in the Multipin concept is the so-called Lanterns [80], where the actual solid support is PS, which can be functionalized in a similar way to PS gel-type supports. 

In conclusion, the concept of solid-supported chemistry has been extended from the preparation of peptides and other biomolecules to any organic molecule. PS-and PEG-based resins are the most widely used however, syntheses can be carried out in any solid support. The development of new solid supports and linkers/ handles is crucial to fulfill the new requirements of modem drag discovery programs. 

The work carried out in the laboratory of the authors was partially supported by CICYT (CTQ2006-03794/BQU), the Generalitat de Catalunya (2005SGR 00662), ISCIII (CIBER, nanomedicine 0074), the Institute for Research in Biomedicine, and the Barcelona Science Park. 

2 Letsinger, R.L. and Mahadevan, V. (1965) Journal of the American Chemical Society, 87, 3526-7. 

3 Merrifield, R.B. (1969) Advances in Enzymology and Related Areas of Molecular Biology, 32, 221-96. 

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Although numerous materials have been used for surface functionalization for solid-phase synthesis [15, 31, 32], the most common, which are commercially available, are membranes and pellicular solid supports, where a mobile polymer... 

An alternative method for achieving the effect of a small diameter is to coat a thin layer of porous solid on a solid core (such as glass). Such materials were widely used in the early days of LC and are usually called pellicular supports. Typically the porous layer is 1-2 pm thick, and the solid core has a diameter of about 40 pm. Pellicular solids are easier to pack than microporous solids, but they are less stable, have smaller capacities, and are more expensive. Since good packing methods are now known for the microporous solids, the pellicular solids have become much less popular. They are commonly used in guard columns (discussed later in this chapter). 

A third group of ion-exchange supports are pellicular, consisting of a solid inert core made of PSDVB agglomerated with 350 nm functionalized latex. The quaternary amine groups are closely and uniformly bound on the microbeads, improving flow and reducing nonspecific retention. These pellicular supports are primarily used for carbohydrate analysis [7]. 

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