Calcein Binding to Assess Mineralization in Hydrogel Microspheres

• Published in: Polymers Vol. 13; no. 14; p. 2274
• Main Authors: White, Kristopher, Chalaby, Rabab, Lowe, Gina, Berlin, Jacob, Glackin, Carlotta, Olabisi, Ronke
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 11.07.2021; MDPI
• Subjects: Alizarin; Biomedical materials; Bone marrow; calcein; Calcium; Calcium phosphates; Cell culture; Colorimetry; Communication; Fluorescence; hydrogel; Hydrogels; Hydroxyapatite; Microscopy; microsphere; Microspheres; Mineral deposits; Mineral oils; Mineralization; osteogenesis; Phosphatase; polymer; Stains & staining; United States > US; polymer; microsphere; mineralization; calcein; osteogenesis; hydrogel
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym13142274

We describe a method to assess mineralization by osteoblasts within microspheres using calcein. Fluorescence imaging of calcein bound to the calcium in hydroxyapatite permits assessment of the mineralized portion of the extracellular matrix. Colorimetric imaging of Alizarin Red S complexed with calcium also gives measures of mineralization, and in tissue cultures calcein and Alizarin Red S have been shown to bind to the same regions of mineral deposits. We show that when the mineralization takes place within hydrogel microspheres, Alizarin Red S does not stain mineral deposits as consistently as calcein. As tissue engineers increasingly encapsulate osteoprogenitors within hydrogel scaffolds, calcein staining may prove a more reliable method to assess this mineralization.