Devil fruits have always been the focus ONE PIECE: Thanks to them, many characters have received special powers and have been able to pursue a career at sea, sometimes for justice and sometimes for their own ends. However, there are many mysteries about devil fruit that remain to be revealed.
With the start of the Egghead saga and the presentation of Vegapunk, Eiichiro Oda immediately wanted to make it clear that readers would be exposed to several high-profile revelations during this period. And indeed, others have arrived Details about artificial devil fruit and how to make it. In fact, in ONE PIECE 1070, the scientist focuses on explaining how to reproduce them.
First, there is one Statement on Zoo Zoo fruits: Inspired by animals, these are the easiest to create. With the manpower, money and time available, virtually every zoo devil fruit will be recreated, and with better results than Caesar Clown's SMILE, which had so many side effects. However, it is not said that these fruits produced in this way can have the Devil Fruit awakening, as happens for the natural ones instead.
Then it's on to the Paramishas, but they work in a completely different way. Because they are not bonded to a sentient animal, they require an "ancestry factor" from the previous carrier, likely a holdover in the DNA that causes the body to change and then harness the powers. This factor must then be synthesized and inserted into the new body for the transmission of powers, with Vegapunk having created a liquid called "green blood" containing this factor.
And the Rogias? Powered by an elemental force in nature, these devil fruits have proven too difficult to synthesize, and as such Vegapunk seems to have thrown in the towel in trying to recreate them. It is no coincidence that these are also the most special, rarest and hardest to find fruits. Did you expect these explanations in ONE PIECE?