The theory that smaller is better--as it is has been in the computer industry--is now driving enthusiasm for nanotechnology, a term that refers to the process of manipulating materials at atomic scale. New players are crowding under this hot rubric, including many working at not nearly so small a scale. Drug discovery methods are among the most compelling near-term nano-applications, but start-ups face challenges like those met by micro-scale pioneers Affymetrix and Caliper. Firms must show they can physically create systems they describe, and that teeny discovery methods actually matter for bench scientists. Business models in this emerging sector reflect the difficulties of harnessing novel science in ways that will satisfy drugmakers who've become extra-tough customers under pressure to deliver commercial results in a shifting, financially depressed market. Some start-ups are working on a fee-for-service basis, on specific projects that address customers' immediate needs. Others are deliberately doing development work on their own, gathering data to attract partnerships that may prove all the more rewarding because of their measured starts.

A preview of the emerging health care companies profiled in the current issue of Start-Up. This month's profile group, G-Protein Coupled Receptors, features profiles of Aptus Genomics Inc., Axovan Ltd., Norak Biosciences Inc. and 7TM Pharma. Plus these Selected Start-Ups across Health Care: ALung Technologies Inc., CancerVax Corp., MedExact Inc. and nanotype GMBH.

Nanotype GMBH has developed an assay system based on molecular force comparison, which measures the forces required to disrupt intermolecular bonds. The basic technology has potential applications in many industries, but the company will initially focus on health care, including drug discovery, genomics, proteomics and pharmacogenomics.