Hi!I'm still at the beginning of bioprinting but i can try to give you few answers.1. Do you mean to literally print the bone or printing a bioink mixture of hydrogels and bone cells? I don't think you can actually do former (as far as i know), while you can find few works on the latter ( Bose 2013 -> review on the matter)2. In order to remove a particular scaffold you have to exploit some of its properies. An example would be printing low viscosity alginate scaffolds, keeping it crosslinked through a small concentration of Ca++ ions (using CaCl2 for example). Once you want to remove the hydrogel you reduce Ca++ concentration so that the alginate returns to liquid form and you can remove it. (look for Colosi 2016 paper on the matter)3. I don't understand what you mean. You can't just scrap cells and seed them. You should think carefully to the cell population to seed into a scaffold. Moreover in order to create a tissue you usually need more than a single cell population. There's a lot to be said/read on the matter, and obviously it also depends on what you want to achieve.