In Vivo Degradation and Biocompatibility Disclosure Register

PROBLEM: The review is candid about what is not solved: mechanistic clarification, biocompatibility optimization, and controlled in vivo degradation. A hafnium particle that stays in the body indefinitely is a different safety story from one that clears on a known schedule, and the engineering literature adds scalable fabrication and long-term biosafety to the same list. These are the questions regulators will ask first — and right now the answers live scattered across papers, with no standing register of what is known, what is assumed, and what is still untested for each formulation.

SOLUTION: An in vivo degradation and biocompatibility disclosure register: every Hf formulation logged with its degradation behavior, its clearance route, its long-term biosafety data, and the gaps still open — so the safety questions are on the record before a regulator has to ask them.

EVIDENCE BASIS: DOCUMENTED — challenges remain in mechanistic clarification, biocompatibility optimization, and controlled in vivo degradation (Chen et al., Biomaterials 2026, abstract); scalable fabrication and long-term biosafety remain open (Gao et al., Adv Healthc Mater 2026). Sources: PubMed 41418721; PubMed 41588825.