title: A scalable approach to obtain mesenchymal stem cells with osteogenic potency on apatite microcarriers.
abstract: Bone tissue engineering, which relies on the interactions between stem cells and suitable scaffold materials, represents a highly desirable alternative to currently used allograft or autograft strategies for the treatment of bone defects caused by injury or disease, with one of the major challenges being to generate sufficient quantities of stem cells to bring about the intended therapeutic effect. However, conventional cell culture to achieve sufficient cell numbers faces limitations of low efficiency and diminished efficacy of stem cells due to repeated passaging. Furthermore, current microcarriers available may not be suitable for therapeutic implantation. Here, the authors featured an apatite-based microcarrier intended for bone tissue engineering applications. These apatite microcarriers have a diameter of ∼230 µm, and exhibited porous and rough surface morphology. Peaks obtained from X-ray diffractometry (XRD) corresponded to hydroxyapatite (HA) with high crystallinity. Fourier transform infrared spectrophotometry (FTIR) showed that no residues of alginate remained, and all bands observed belong to phosphate and hydroxyl groups of HA. To evaluate the cytocompatibility of these microcarriers, in vitro proliferation studies were conducted and compared with conventional monolayer as well as Cytodex 3. The authors found that human foetal mesenchymal stem cells (hfMSCs) cultured on apatite microcarriers exhibited comparable growth characteristics, achieving 1.4-fold higher live cells than Cytodex 3 over a 9-day culture period. As these microcarriers were hypothesised to offer enhanced osteogenic potency over conventional monolayer culture, alkaline phosphatase (ALP), type I collagen and osteocalcin expression of hfMSCs cultured on the apatite microcarriers were evaluated over a 12-day period. ALP expression for hfMSCs seeded on apatite microcarriers was 2.7-fold higher than that of adherent monolayer culture (p < 0.001). Additionally, type I collagen and osteocalcin expression were 1.8- and 1.5-fold higher than that of adherent monolayer culture on day 12, respectively (p < 0.001).
authors: Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, Singapore, Singapore.
authors: Jason
authors: J
authors: Feng
authors: Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore.
authors: Mark
authors: M
authors: Chong
authors: Department of Reproductive Medicine, Division of Obstetrics & Gynaecology, KK Women's and Children's Hospital, Singapore, Singapore Department of Obstetrics & Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
authors: Jerry
authors: J
authors: Chan
authors: Department of Plastic and Reconstructive Surgery, Shanghai 9 People's Hospital, Shanghai Jiao Tong University, Xuhui, Shanghai, China.
authors: Zhiyong
authors: Z
authors: Zhang
authors: Division of Bioengineering, School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore.
authors: Swee Hin
authors: SH
authors: Teoh
authors: Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, Singapore, Singapore mpetes@nus.edu.sg.
authors: Eng San
authors: ES
authors: Thian
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D001031:Apatites / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D024042:Collagen Type I / Q000378:metabolism; D053686:Fetal Stem Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008422:Materials Testing; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000378:metabolism; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis; D023822:Tissue Engineering; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001031:Apatites; D001672:Biocompatible Materials; D024042:Collagen Type I; D015675:Osteocalcin; D000469:Alkaline Phosphatase
keywords: Apatite; microcarriers; osteogenesis; scalable; stem cell