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.