Braided Silk by Ella Drake
Rapunzel was made with technologically advanced hair. As a trained Mother agent, Zel can't escape the DNA that makes her a pawn in corporate espionage. Kidnapped and held in a tower on Gothel Island, she falls to the sexual allure of her captor's son, Langley, a man whose every tantalizing touch makes her forget she wasn't born human.
Langley Gothel protests the existence of creations such as Zel, but when faced with losing her, he sees the truth: Life is precious, whether born, modified, or shaped in a Petri dish. He does the one thing he's thought he'd never do. He has to give up Zel, or become a mod. But will that be enough to get them down from the floating islands and safely to ground?
This story has been revised and expanded. It was also previously available in the box set Once Upon a Fairytale.