Publications

@article{Owen2024-ih,

title = {β-glycerophosphate, not low magnitude fluid shear stress,  increases osteocytogenesis in the osteoblast-to-osteocyte cell  line IDG-SW3},

author = {Robert Owen and Claudia Wittkowske and Damien Lacroix and Cecile M Perrault and Gwendolen C Reilly},

doi = {10.1080/03008207.2024.2375065},

year  = {2024},

date = {2024-07-01},

urldate = {2024-07-01},

journal = {Connect. Tissue Res.},

volume = {65},

number = {4},

pages = {313\textendash329},

publisher = {Informa UK Limited},

abstract = {AIM: As osteoblasts deposit a mineralized collagen network, a 

 subpopulation of these cells differentiates into osteocytes. 

 Biochemical and mechanical stimuli, particularly fluid shear 

 stress (FSS), are thought to regulate this, but their relative 

 influence remains unclear. Here, we assess both biochemical and 

 mechanical stimuli on long-term bone formation and 

 osteocytogenesis using the osteoblast-osteocyte cell line 

 IDG-SW3. METHODS: Due to the relative novelty and uncommon 

 culture conditions of IDG-SW3 versus other osteoblast-lineage 

 cell lines, effects of temperature and media formulation on 

 matrix deposition and osteocytogenesis were initially 

 characterized. Subsequently, the relative influence of 

 biochemical (β-glycerophosphate (βGP) and ascorbic 

 acid 2-phosphate (AA2P)) and mechanical stimulation on 

 osteocytogenesis was compared, with intermittent application of 

 low magnitude FSS generated by see-saw rocker. RESULTS: 

 βGP and AA2P supplementation were required for 

 mineralization and osteocytogenesis, with 33°C cultures 

 retaining a more osteoblastic phenotype and 37°C cultures 

 undergoing significantly higher osteocytogenesis. βGP 

 concentration positively correlated with calcium deposition, 

 whilst AA2P stimulated alkaline phosphatase (ALP) activity and 

 collagen deposition. We demonstrate that increasing βGP 

 concentration also significantly enhances osteocytogenesis as 

 quantified by the expression of green fluorescent protein linked 

 to Dmp1. Intermittent FSS (~0.06 Pa) rocker had no effect on 

 osteocytogenesis and matrix deposition. CONCLUSIONS: This work 

 demonstrates the suitability and ease with which IDG-SW3 can be 

 utilized in osteocytogenesis studies. IDG-SW3 mineralization was 

 only mediated through biochemical stimuli with no detectable 

 effect of low magnitude FSS. Osteocytogenesis of IDG-SW3 

 primarily occurred in mineralized areas, further demonstrating 

 the role mineralization of the bone extracellular matrix has in 

 osteocyte differentiation.},

keywords = {biomechanics, bone tissue engineering, extracellular matrix, Matrix mineralization, mechanobiology},

pubstate = {published},

tppubtype = {article}

}

@article{Owen2020-lk,

title = {Combined porogen leaching and emulsion templating to produce 

 bone tissue engineering scaffolds},

author = {Robert Owen and Colin Sherborne and Richard Evans and Gwendolen C Reilly and Frederik Claeyssens},

year  = {2020},

date = {2020-04-01},

journal = {Int. J. Bioprinting},

volume = {6},

number = {2},

pages = {265},

publisher = {AccScience Publishing},

abstract = {Bone has a hierarchy of porosity that is often overlooked when 

 creating tissue engineering scaffolds where pore sizes are 

 typically confined to a single order of magnitude. High internal 

 phase emulsion (HIPE) templating produces polymerized HIPEs 

 (polyHIPEs): highly interconnected porous polymers which have 

 two length scales of porosity covering the 1-100 μm range. 

 However, additional larger scales of porosity cannot be 

 introduced in the standard emulsion formulation. Researchers 

 have previously overcome this by additively manufacturing 

 emulsions; fabricating highly microporous struts into complex 

 macroporous geometries. This is time consuming and expensive; 

 therefore, here we assessed the feasibility of combining porogen 

 leaching with emulsion templating to introduce additional 

 macroporosity. Alginate beads between 275 and 780 μm were 

 incorporated into the emulsion at 0, 50, and 100 wt%. Once 

 polymerized, alginate was dissolved leaving highly porous 

 polyHIPE scaffolds with added macroporosity. The compressive 

 modulus of the scaffolds decreased as alginate porogen content 

 increased. Cellular performance was assessed using MLO-A5 

 post-osteoblasts. Seeding efficiency was significantly higher 

 and mineralized matrix deposition was more uniformly deposited 

 throughout porogen leached scaffolds compared to plain 

 polyHIPEs. Deep cell infiltration only occurred in porogen 

 leached scaffolds as detected by histology and lightsheet 

 microscopy. This study reveals a quick, low cost and simple 

 method of producing multiscale porosity scaffolds for tissue 

 engineering.},

keywords = {Alginate, bone tissue engineering, Emulsion templating, Multiscale porosity, Polymerized high internal phase emulsions},

pubstate = {published},

tppubtype = {article}

}

@article{Owen2020-gt,

title = {Comparison of the anabolic effects of reported osteogenic 

 compounds on human mesenchymal progenitor-derived osteoblasts},

author = {Robert Owen and Hossein Bahmaee and Frederik Claeyssens and Gwendolen C Reilly},

year  = {2020},

date = {2020-01-01},

journal = {Bioengineering (Basel)},

volume = {7},

number = {1},

pages = {12},

publisher = {MDPI AG},

abstract = {There is variability in the reported effects of compounds on 

 osteoblasts arising from differences in experimental design and 

 choice of cell type/origin. This makes it difficult to discern a 

 compound's action outside its original study and compare 

 efficacy between compounds. Here, we investigated five compounds 

 frequently reported as anabolic for osteoblasts 

 (17β-estradiol (oestrogen), icariin, lactoferrin, lithium 

 chloride, and menaquinone-4 (MK-4)) on human mesenchymal 

 progenitors to assess their potential for bone tissue 

 engineering with the aim of identifying a potential alternative 

 to expensive recombinant growth factors such as bone 

 morphogenetic protein 2 (BMP-2). Experiments were performed 

 using the same culture conditions to allow direct comparison. 

 The concentrations of compounds spanned two orders of magnitude 

 to encompass the reported efficacious range and were applied 

 continuously for 22 days. The effects on the proliferation 

 (resazurin reduction and DNA quantification), osteogenic 

 differentiation (alkaline phosphatase (ALP) activity), and 

 mineralised matrix deposition (calcium and collagen 

 quantification) were assessed. Of these compounds, only 10 µM 

 MK-4 stimulated a significant anabolic response with 50% 

 greater calcium deposition. Oestrogen and icariin had no 

 significant effects, with the exception of 1 µM icariin, which 

 increased the metabolic activity on days 8 and 22. 1000 µg/mL of 

 lactoferrin and 10 mM lithium chloride both significantly 

 reduced the mineralised matrix deposition in comparison to the 

 vehicle control, despite the ALP activity being higher in 

 lithium chloride-treated cells at day 15. This demonstrates that 

 MK-4 is the most powerful stimulant of bone formation in hES-MPs 

 of the compounds investigated, highlighting its potential in 

 bone tissue engineering as a method of promoting bone formation, 

 as well as its prospective use as an osteoporosis treatment.},

keywords = {bone formation, bone tissue engineering, matrix mineralisation, menaquinone-4, mesenchymal stem cells, osteoblasts, osteoporosis, vitamin K},

pubstate = {published},

tppubtype = {article}

}