Abstract
Hydroxyapatite (HA) or calcium carbonate (CaCO3) formed on an organic polymer of agarose gel is a biomaterial that can be used for bone tissue regeneration. However, in critical bone defects, the regeneration capability of these materials is limited. Mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into bone forming osteoblasts. In this study, we loaded MSCs on HA- or CaCO3-formed agarose gel and cultured them with dexamethasone, which triggers the osteogenic differentiation of MSCs. High alkaline phosphatase activity was detected on both the HA- and CaCO3-formed agarose gels; however, basal activity was only detected on bare agarose gel. Bone-specific osteocalcin content was detected on CaCO3-formed agarose gel on Day 14 of culture, and levels subsequently increased over time. Similar osteocalcin content was detected on HA-formed agarose on Day 21 and levels increased on Day 28. In contrast, only small amounts of osteocalcin were found on bare agarose gel. Consequently, osteogenic capability of MSCs was enhanced on CaCO3-formed agarose at an early stage, and both HA- and CaCO3-formed agarose gels well supported the capability at a later stage. Therefore, MSCs loaded on either HA- or CaCO3-formed agarose could potentially be employed for the repair of critical bone defects.
Highlights
We have established methods for hydroxyapatite (HA) formation on or in organic polymer hydrogel matrices [1,2,3,4], which involve alternate soaking of the polymer in calcium chloride and disodium hydrogenphosphate aqueous solutions
Bone tissue regeneration was not observed in defects implanted with mineralized agarose lacking Mesenchymal stem cells (MSCs). These findings demonstrated that loading MSCs onto the mineralized gels strengthens their osteogenic capability; MSC-loading has potential for applications in bone tissue regeneration
Morphological data showed that raw agarose gel did not support the adhesion/attachment of MSCs, resulting in low levels of cell proliferation on the gel
Summary
We have established methods for hydroxyapatite (HA) formation on or in organic polymer hydrogel matrices [1,2,3,4], which involve alternate soaking of the polymer in calcium chloride and disodium hydrogenphosphate aqueous solutions. We investigated the potential of calcium carbonate formed on/in agarose gel (CaCO3/agarose) as a biomaterial for bone tissue regeneration. HA/agarose and CaCO3/agarose appear to be excellent biomaterials for regeneration of bone defects in our previous studies, the sites of the periodontal defects [9], tooth extraction sockets [10], and femoral bone defects [4] were surrounded by abundant pre-existing host bone; they could be considered partial bone defects with the potential for some spontaneous bone healing. When combined with mesenchymal stem cells (MSCs), various materials have osteogenic functions and are capable of forming new bone following in vivo implantation [13,14,15,16,17] Based on these findings, in our previous work, we loaded MSCs onto HA/agarose (MSCs/HA/agarose) and CaCO3/agarose (MSCs/CaCO3/agarose) and implanted them into critical cranial bone defects [12]. In the present paper, we used in vitro tissue culture methods to investigate the role of MSC-loading in the osteogenic differentiation capability of MSC/HA/agarose and MSC/CaCO3/agarose
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
