Particle Size of Hydroxyapatite Granules Calcified from Red Algae Affects the Osteogenic Potential of Human Mesenchymal Stem Cells in vitro

Abstract

Hydroxyapatite (HA) microparticles as a carrier in an injectable tissue-engineered bone filler are considered promising candidates for the treatment of small bone defects in the craniomaxillofacial region. HA granules calcified from red algae, varying in size, were evaluated in vitro for their suitability to be used as a carrier for human mesenchymal stem cells (hMSCs). Three groups of granules were produced in grain sizes of 10–100, 200–500 and 600–1,000 µm. After seeding and culturing hMSCs under osteogenic differentiation conditions onto HA particles for 3, 6 and 9 days, cellular proliferation (tetrazolium salt, XTT), alkaline phosphatase (ALP)-specific activity and total protein synthesis were investigated. The osteoblastic phenotype of the cells was evaluated by assaying the bone-specific genes osteocalcin, osteopontin and collagen type I. XTT assay revealed significantly higher (p < 0.01) proliferation of cells grown on the smallest grain size after 9 days of culture. Regarding ALP-specific activity, significantly higher levels of activity were detected in cells grown on the smallest grain size. Different grain sizes had no significant effects on the secretion of osteocalcin and osteopontin. Collagen type I production was significantly higher (p < 0.05) in cells grown on the biggest grain size in comparison with the two other grain sizes. These results show that the particle size of HA microparticles affects the osteogenic potential of cultured hMSCs and lead to the conclusion that particle size has differential effects on ALP-specific activity and collagen type I production.

An in vitro Study to Assess the Potential of a Unique Micro porous Algal Derived Cap Bone Void Filler in Comparison with Clinically-Used Bone Void Fillers

“…At day 7, no significant difference was found between Bone Save ® and Pro-Osteon TM at day 7, despite having a similar chemical composition (Table 2). This indicates that particle size has a significant influence on cell behaviour in vitro and supports work by Weiβ enböck et al, who found that particle size and substrate geometry significantly influenced cell signaling [30].…”

“…The main benefit of coral-derived bone void fillers over synthetic alternatives is their bioresorption capacity [25,26]. Recently, other sustainable calcified marine structures and organisms, such as mussels [27, cuttlefish bone [28] and algae [26,29,30] have been investigated for bone void filler applications.…”

Small-sized granules of biphasic bone substitutes support fast implant bed vascularization

“…8 A variety of in vitro and in vivo studies have been conducted to quantify the impact of this factor on the progress and outcome of bone regeneration, but no definitive conclusions have thus far been reached. [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] Following previous studies conducted by our group analyzing tissue reactions to bone substitute materials with a special focus on their chemical composition and physical characteristics, the present study investigates the influence of granule size of a biphasic bone substitute material. In this investigation 2 granule sizes of BoneCeramic Ò (500-1000 mm and 400-700 mm) were tested with respect to the tissue reaction in a subcutaneous implantation model in Wistar rats over a 60 day period.…”

Adipose derived mesenchymal stem cells – Their osteogenicity and osteoblast in vitro mineralization on titanium granule carriers

“…We chose to culture the cells on the inserts with the subsequent risk of escape of cells through the net of the inserts instead of culturing directly on the wells, as performed in similar other published experiments (Hosseinkhani et al, 2005;Turhani et al, 2005;Shih et al, 2006;Weissenböeck et al, 2006;Zhou et al, 2007;Bjerre et al, 2008;Heo et al, 2009;Huang et al, 2009;Shi et al, 2009;Stiehler et al, 2009). This makes change of the medium Fig.…”