Pe conjugated sca 1

All work involving primary cell extraction was conducted under approved animal welfare protocols (Institutional Animal Care and Use Committee, University of Illinois at Urbana-Champaign). Murine hematopoietic stem and progenitor cells (HSPCs) and mesenchymal stromal progenitor cells (MSPCs) were cultured in methacrylamide-functionalized gelatin (GelMA) following the isolation and culture protocols outlined previously [46 (link)]. In brief, HSPCs were isolated from the crushed tibiae and femora of C57BL/6 female mice, age 4–8 weeks (The Jackson Laboratory). Initial hematopoietic lineage negative enrichment was performed with EasySep™ Mouse Hematopoietic Progenitor Cell Isolation Kit (#19856, Stemcell Technologies, CA), followed by collection of the Lin⁻ Sca-1⁺ c-kit⁺ (LSK) fraction using a BD FACS Aria II flow cytometer. LSK antibodies were supplied by eBioscience (San Diego, CA) and are as follows: APC-efluor780-conjugated c-kit (1:160, #47–1172–81), PE-conjugated Sca-1 (0.3:100, #12–5981–83) and Lin: FITC-conjugated CD5, B220, CD8a, CD11b (1:100, #11–0051–82, #11–0452–82, #11–0081–82, #11–0112–82), Gr-1 (1:400, #11–5931–82) and Ter-119 (1:200, #11–5921–82) [1 (link), 47 (link), 48 (link)]. MSPCs were isolated from the crushed bone following a commercially available protocol and cultured for 10 days prior to collection and use (#05513, Stemcell Technologies).