You imply that the insiders have BOUGHT 2% of the float. That is incorrect. No insider has EVER bough a single actc share. They are given them free, in additional to their outrageous salaries. Hence the dilution (well, the many lawsuit judgements/payments, and the insider freebies).
When Langer buys his first share of ACTC, that will be you signal to "invest". Until then actc is a trading vehicle, which is best shorted, second best swing traded.