Is there research using peptides like igf to improve insulin sensitivity for type 2 diabetics?

Yes. Igf-1 is a potent glucose lowering agent, in fact the new Insulin analogs Humalog (insulin lispro) and NovoLog have alterations in one of the Insulin components that were derived from the observation that when igf-i was injected through the skin it lowered the sugar faster than regular insulin.