A range of fine bioactive glass (BC) fibers with different hydrolysis degree were synthesized via a sol-gel and electrospinning approach. Due to the increased water/TEOS ratio (X ratio) from 2 to 8, the Si-O-Si network integrity of BG fibers was dramatically enhanced. With a designed protein loading method using simulated body fluid (SBF)/bovine serum albumin (BSA) mixture solution, the tunable protein releasing was successfully achieved. The varied hydrolysis degree of BC fibers was found to induce distinctive releasing behavior. The protein release kinetics intends to present a more controlled and sustained manner with the decreased X ratio from 8 to 2, and such phenomenon is mainly attributed to the 'anchoring' effect of the crystalline apatite mineral layers formed at the fiber surface. This study has therefore offered another way of thinking in the investigation of feasible multifunctionalization strategies for bioactive glasses, and thus provided an impetus to the current research for future advanced BC scaffold materials. (C) 2014 Elsevier B.V. All rights reserved.