SERIAL ENTREPRENEUR AND MASSACHUSETTS Institute of Technology professor Robert Langer is a biotechnology legend whose half dozen Boston-area start-up companies don’t lack for investors. So Langer surprised the high-tech world late last year when he announced his newest partner: the Russian government. 

Not the Kremlin, exactly. Rusnano, a state-backed investment firm, put up half of a financing round that poured $94.5 million into two shops where Langer is a core investor: Selecta Biosciences, which is developing a genetically engineered drug to block the addictive effects of nicotine, and BIND Biosciences, working on a potentially blockbuster cancer drug. Rusnano also agreed to invest $26 million in a joint venture with Cleveland BioLabs, another U.S. start-up that is looking to engineer oncological treatments.

The U.S. investments were a first for Rusnano, founded in 2007 to seed tech companies....