Insulet Corp. (Nasdaq: PODD), a Bedford, Mass.-based maker of wireless glucose pumps for diabetics, has filed for a secondary public offering of around 4.77 million shares. It would raise just over $113 million, based on yesterday's closing stock price of $23.77 per share. Selling shareholders include Alta Partners, SV Life Sciences, Pequot Capital, Prism VentureWorks, TIAA-CREF, MedVentures and Silicon Valley Bank. Each of those firms, with the exception of MedVentures, will retain shares following the offering. www.insulet.com