One of the reasons gene therapy has faltered so far is that it's hard to get the right genes into cell nuclei safely. Genetically modified viruses are a common but less-than-ideal vehicle for the genes because the viruses can cause a fatal immune response. Looking for a way to deliver the genetic goods harmlessly and efficiently, cancer researcher Gayle Woloschak of Northwestern University Medical School and researchers at Argonne National Laboratory are turning to nanocrystals-particles a few billionths of a meter in diameter.

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