biostudies-literatureUnknown13Le K<h4>Introduction</h4>Monoosteophils, derived from LL-37-treated monocytes, are a novel type of calcifying/bone forming cells. We have shown that monoosteophils can form bone-like nodules <i>in vitro</i> and accelerate bone repair in a drilled femur defect model. Here, we explored the bone repair function of monoosteophils in a mouse model of critical-sized calvarial defect and the mechanism of bone nodule formation of monoosteophils <i>in vitro</i>.<h4>Methods</h4>Human monocytes were isolated from peripheral blood and differentiated into monoosteophils. Critical-sized (5 mm-diameter) calvarial defects in the parietal bone of adult male NOD/SCID mice were implanted with either 1-day untreated human monocytes, 1-day LL-37 treated human monocytes (monoosteophils), 1-day human monocytes plus Frontiers in bioengineering and biotechnology1583496https://www.ebi.ac.uk/biostudies/studies/S-EPMC12301765biostudies-literatureA pilot study of healing critical-sized calvarial defects by LL-37-generated monoosteophils.PMC12301765Le KLiu HShively JEOlafsen TLi ZZhang ZFong YZhang CfalseA pilot study of healing critical-sized calvarial defects by LL-37-generated monoosteophils.<h4>Introduction</h4>Monoosteophils, derived from LL-37-treated monocytes, are a novel type of calcifying/bone forming cells. We have shown that monoosteophils can form bone-like nodules <i>in vitro</i> and accelerate bone repair in a drilled femur defect model. Here, we explored the bone repair function of monoosteophils in a mouse model of critical-sized calvarial defect and the mechanism of bone nodule formation of monoosteophils <i>in vitro</i>.<h4>Methods</h4>Human monocytes were isolated from peripheral blood and differentiated into monoosteophils. Critical-sized (5 mm-diameter) calvarial defects in the parietal bone of adult male NOD/SCID mice were implanted with either 1-day untreated human monocytes, 1-day LL-37 treated human monocytes (monoosteophils), 1-day human monocytes plus 2025-01-01T00:00:00Z20252025-08-24T03:04:20.619Z2025-08-21T09:52:57.25ZS-EPMC123017654072764710.3389/fbioe.2025.1583496