Yinling Wang

1 Introduction The periosteum is a highly vascularized connective tissue that covers almost the entire bone surface. It acts as the “umbilical cord” of bone tissue and consists of an outer fibrous layer and an inner cambium layer [1]. The dense outer layer involves abundant capillaries and well-organized aligned collagenous fibers, providing structural support and over 70% blood supply for the underlying bone tissue [2].

Electrochemiluminescence (ECL) is a luminescence process in which energy is radiatively released from an excited state luminophore, which is produced by a ground-state luminophore that is first electrically stimulated and then chemically converted [1], [2].

Highlights Control of radical concentrations by oxygen initiation and storage Manipulation of radical structures by B-alkylcatecholborane Precise synthesis of ultra-high-molecular-weight (co)polymers Quantitative initiation efficiency by a radical catalytic cycle Summary Ultra-high-molecular-weight (UHMW) polymers can display outstanding properties; however, it is challenging to synthesize UHMW polymers by using external free radical initiators.