UTS site search

Dr Joshua Chou

Biography

Dr. Joshua Chou is a Chancellor’s Postdoctoral Fellow in the Department of Medical and Molecular Bioscience as well as a core member of the Centre of Health Technology at UTS. Joshua finished his Ph.D. here at UTS where his research was based on using biomimetic materials for bone tissue regeneration. Currently his research is based on developing drug delivery systems for stimulating and guiding bone regeneration with particular emphasis in developing bioinspired biomaterials and applying stem cell technologies for tissue engineering. Furthermore, Dr. Chou holds a Graduate Certificate in Project Management from The University of Sydney and is currently undertaking a Graduate Certificate in Higher Education.

While still an Early Career Researcher, Dr. Chou’s interdisciplinary research has during the past 2 years been published in high impact journals including Journal of Tissue Engineering and Regenerative Medicine, Advanced Functional Materials, Advanced Healthcare Materials, Journal of Australia Ceramic Society.

Dr. Chou was awarded the Endeavour Award in 2011 where he spent 6 months with our industry collaborator in Japan. This research was presented at the 2011 Asian Bioceramic Symposium where he was awarded “Best Presentation Award”.

Dr. Chou is an Editor for the Journal of Australia Ceramic Society and the Journal of Advances in Ceramic Science and Engineering. He also serves as a member of the editorial board for Journal of Tissue Engineering and Regenerative Medicine and International Journal of Biomaterials.

Dr. Chou’s research has had publicity in the national media: radio (ABC), newspaper (Sydney Morning Herald (2010) and magazines (Materials Australia, U:Magazine, Researcher in Focus). Dr. Chou will also be speaking at the 2012 Ultimo Science Festival and at UTS Teacher’s Open Day.

Professional

  • Tissue Engineering and Regenerative Medicine Society (TERMIS) (Since 2010)
  • Australian Ceramic Society (Since 2007)
  • Australasian Society for Biomaterials & Tissue Engineering (Since 2007)
  • Australia Institute of Project Management (Since 2006)

Image of Joshua Chou
Core Member, CHT - Centre for Health Technologies
Lecturer, School of Life Sciences
BSc in Nanotechnology, BSC in Honours, Grad Cert PM (USyd), Doctor of Philosophy
 
Phone
+61 2 9514 1729

Dr. Chou is highly interested in teaching students and currently co-supervise 1 PhD student but is actively involved with other teaching duties.

1) Cell Biology and Genetics (91161)
Guest Lecturer/Lab demonstrator (Since 2007)

2) Essentials of Pathophysiology (99636)
Lab demonstrator (2007-2010)

3) Intro. Pharmacology and Microbiology (91604)
Lab demonstrator (2010)

4) Medical Devices and Diagnostics (91705)
Lab demonstrator (2010)

5) Introduction to Materials (68070)
Tutor/Lab demonstrator (Since 2007)

6) Chemistry and Materials Science (60101)
Tutor/Lab demonstrator (Since 2007)

Chapters

Chou, J. & Hao, J. 2016, 'Marine biomaterials as drug delivery system for osteoporosis and bone tissue regeneration' in Handbook of Bioceramics and Biocomposites, Springer, Germany, pp. 1309-1332.
View/Download from: Publisher's site
© Springer International Publishing Switzerland 2016.There is currently an urgent need to develop sustainable and therapeutically relevant advanced drug delivery systems to treat the prevalence of ongoing human diseases and ailments. The effectiveness of such system will depend primarily on the properties and characteristics of the carrier material. In this chapter, marine materials are investigated as potential drug delivery carriers for bone tissue engineering and in the treatment of osteoporosis. This chapter will explore the unique structures of marine materials that set it apart from its synthetic counterparts and the conversion to biocompatible calcium phosphates combined with synthetic modifications, and case studies will demonstrate the potential clinical applications.
Ben-Nissan, B., Choi, A.H., Green, D.W., Latella, B.A., Chou, J. & Bendavid, A. 2011, 'Synthesis and Characterization of Hydroxyapatite Nanocoatings by Sol-Gel Method for Clinical Applications' in Sam Zhang (ed), Biological and Biomedical Coatings Handbook: Processing and Characterization, CRC Press, United States, pp. 37-79.
View/Download from: UTS OPUS
Nanostructured materials are associated with a diversity of uses within the medical field, for instance, in drug-delivery systems, regenerative medicine, formation of surgical tools, medical devices, and diagnostic systems. It has long been established that porous bulk hydroxyapatite (HAp) cannot be used for load-bearing applications due to its unfavorable mechanical properties. As a result, HAp has been used instead as a coating in orthopedic surgery on metallic alloys, metals giving the support required. Of the metallic alloys used, titanium-based and cobalt chromium alloys are the preferred materials for these HAp coatings for orthopedic and maxillofacial implants (Figure 2.1).

Conferences

Ekren, N., Gunduz, O., Celik, S., Ayata, B., Sahin, Y.M., Chou, J., Ben-Nissan, B., Salman, S., Gokce, H. & Oktar, F.N. 2016, 'Production of apatite from snail shells for biomedical engineering applications', Key Engineering Materials, pp. 51-56.
View/Download from: Publisher's site
© 2016 Trans Tech Publications, Switzerland.Bioceramics is very important application for dental and orthopedic procedures. Beside all these normal procedures traffic accidents are requiring increasing number of graft, prostheses and orthosis applications. Bioceramics can be produced from local and natural sources with various methods. Those can be produced from various bone structures through calcination (at high temperatures) or with diluted hydrochloric acid (HCl) application & freeze drying. Beside these methods calcite and aragonite structures like from sea shells and egg shells bioceramic production can be realized through mechanochemical processing via a simple hot-plate or ultrasonic equipment. A fresh water snail shell (Zebra Nerite Snail-Neritina natalensis) was prepared as bioceramic production source. The resulting hydroxyapatite (HA) powders were obtained without any impurities. At two varying temperature of 865 and 885 0C the snail shells was transformed to HA bioceramics. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential thermal analysis (TG/DTA) were evaluated.
Inan, A.T., Gunduz, O., Sahin, Y.M., Ekren, N., Salman, S., Chou, J., Ben-Nissan, B., Gokce, H. & Oktar, F.N. 2016, 'Novel Bioceramic production via mechanochemical conversion from plate limpet (Tectura scutum)-Shells', Key Engineering Materials, pp. 45-50.
View/Download from: Publisher's site
© 2016 Trans Tech Publications, Switzerland.Calcium phosphates are very important biomaterials for orthopaedic and dental applications. Hydroxyapatite (HA) is one of the important phases used for grafting. Those are produced from synthetic and natural sources with various methods. Especially nano-bioceramics can be produced through calcitic and aragonitic structures (i.e. mussel shells, sea snail shells, land snail shells and sea urchin shells). The plate limpet shells were used. The plate limpet is a gastropod, a soft-bodied invertebrate (an animal without a backbone) that is protected by a very hard, flattened conical shell. In this study the Plate Limpet (Tectura scutum) shells were obtained from a local gift store in Istanbul. The habitation of these limpets broadens from south Alaska down to California-Mexico. First the exact 97 % CaCO3 content was measured with thermal analysis (DTA/TGA). Here in this study agitation was preformed on a hot-plate. First the temperature was fixed at 80 °C for 15 min. Then equivalent amount to 1.92 mmol CaO H3PO4 was added dropwise for affecting HA phase formation and the reaction was set on a hotplate for 8 hours. The dried sediments HA part was divided into 2 groups. One group was sintered to 835 °C and second group to 855 °C. Here x-ray diffraction and scanning electron microscope (SEM) analyses were performed. From the study various HA phases and TCP phases were obtained. A previous study done with Atlantic Deer Cowrie encourages nanobioceramic production from natural sources. This study proposes that mechanochemical agitation with very simple way for producing nano-sized calcium phosphates for future bioengineering scaffold applications.
Green, D., Padula, M., Santos, J., Chou, J., Milthorpe, B.K. & Ben-Nissan, B. 2012, 'A new role for marine skeletal proteins in regenerative orthopaedics', Key Engineering Materials (Volumes 529 - 530) bioceramics 24, Bioceramics, Scientific.net, Fukuoka, Japan, pp. 654-659.
View/Download from: Publisher's site
Use of ready-made marine skeletons is one of the simplest possible remedies to major problems hindering the future development of regenerative orthopaedics- such as, providing a richness of framework designs and now a potentially rich, accessible source

Journal articles

Chou, J., Ito, T., Otsuka, M., Ben-Nissan, B. & Milthorpe, B. 2016, 'The effectiveness of the controlled release of simvastatin from -TCP macrosphere in the treatment of OVX mice.', Journal of tissue engineering and regenerative medicine, vol. 10, no. 3, pp. E195-E203.
Simvastatin, a cholesterol treatment drug, has been shown to stimulate bone regeneration. As such, there has been an increase interest in the development of suitable materials and systems for the delivery of simvastatin. Without the appropriate dosage of simvastatin, the therapeutic effects on bone growth will be significantly reduced. Furthermore, similar to many pharmaceutical compounds, at high concentration simvastatin can cause various adverse side-effects. Given the associated side-effects with the usage of simvastatin, the development of suitable controlled drug release system is pertinent. Calcium phosphate in particularly beta-tricalcium phosphate (-TCP) has been extensively studied and used as a carrier material for drug delivery system. In this study, Foraminifera exoskeletons were used as calcium carbonate precursor materials, which were hydrothermally converted to -TCP as a carrier material for simvastatin. Natural marine exoskeletons posses interconnected and uniformly porous network capable of improving drug loading and release rate. To prolong the release of simvastatin, an apatite coating was made around the -TCP sample and in vitro release studies in simulated body fluid (SBF) showed a significant decrease in release rate. Osteoporotic mice were used to examine the compare therapeutic effectiveness of -TCP, -TCP with simvastatin, apatite-coated -TCP with simvastatin and direct injection of simvastatin near the right femur of the mice. Localized and systemic effect were compared with the femur of the non-implanted side (left) and showed that -TCP with or without simvastatin was able to induce significant bone formation over 6weeks. Mechanical analysis showed that apatite-coated -TCP with simvastatin produced significantly stronger bones compared with other experimental groups. This study shows that natural exoskeletons with the appropriate structure can be successfully used as a drug delivery system for simvastatin and can its release ca...
Chou, J., Komuro, M., Hao, J., Kuroda, S., Hattori, Y., Ben-Nissan, B., Milthorpe, B. & Otsuka, M. 2016, 'Bioresorbable zinc hydroxyapatite guided bone regeneration membrane for bone regeneration', Clinical Oral Implants Research, vol. 27, no. 3, pp. 354-360.
View/Download from: Publisher's site
Hattori, Y., Mori, H., Chou, J. & Otsuka, M. 2016, 'Mechanochemical synthesis of zinc-apatitic calcium phosphate and the controlled zinc release for bone tissue engineering.', Drug development and industrial pharmacy, vol. 42, no. 4, pp. 595-601.
In this study, in order to control zinc (Zn)-release from calcium phosphate (CaP), the crystalline forms of CaP-containing Zn were modified by wet ball milling and/or heat treatment. The CaP (CaO:CaHPO4:ZnO = 7:20:3, molar ratio) was ground in a ball mill with the addition of purified water, and the ground products were heated to 400 °C and 800 °C. The physicochemical properties of these ground products were measured by powder X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy and energy-dispersive X-ray spectroscopy. Zn release characteristics from the samples were evaluated using a dissolution tester. The results of XRD and IR suggested that the structures of the starting materials were destroyed after 2.5 h of grinding, and new apatite-like amorphous solid containing Zn was generated. The Zn-release from the ground products was markedly suppressed after 2.5 h of grinding.
Nguyen Vo, T.N., Hao, J., Chou, J., Oshima, M., Aoki, K., Kuroda, S., Kaboosaya, B. & Kasugai, S. 2016, 'Ligature induced peri-implantitis: tissue destruction and inflammatory progression in a murine model.', Clinical oral implants research.
The aim of this study was to investigate tissue destruction and inflammatory progression of ligature-induced peri-implantitis in mice and to establish an alternative murine model of peri-implantitis.Sixty male C57BL/6NCrSlc mice (4-week-old) were used and the maxillary right first molars were extracted. Eight weeks after extraction, custom-made pure titanium machined screw type implants (0.8&nbsp;&nbsp;1.5&nbsp;mm) were placed, one implant per animal. Four weeks later, 5-0 silk ligatures were applied around implant necks to induce peri-implantitis. Animals were sacrificed at 0 (before ligature), 7, 14, 21 and 28&nbsp;days after ligature. Half of the samples were analyzed radiologically and histologically to measure bone level change, osteoclast number, density, and distribution. The rest of the samples was used to determine the relative mRNA expression levels of IL-1 and TNF- with RT-PCR analysis.Bone levels at all sites (buccal, palatal, mesial, distal) decreased 40-50% significantly 28&nbsp;days after ligature (P&nbsp;<&nbsp;0.01). Osteoclast number at all post-ligature time points increased significantly (P&nbsp;<&nbsp;0.05). However, their density at day 28 decreased significantly compared to that of day 21 (P&nbsp;<&nbsp;0.05). Accordingly, IL-1 and TNF- mRNA expression increased significantly at the early time points but decreased significantly at day 28 after ligature (P&nbsp;<&nbsp;0.05).Inflammatory response followed by significant peri-implant bone resorption suggested 28&nbsp;days ligation is sufficient to successfully induce peri-implantitis in the current mice model. This model might open a new avenue to study the pathogenesis and mechanism of peri-implantitis.
Andronescu, E., Brown, J.M., Oktar, F.N., Agathopoulos, S., Chou, J. & Obata, A. 2016, 'Nanomaterials for Medical Applications: Benefits and Risks', Journal of Nanomaterials, vol. 2016.
View/Download from: Publisher's site
Chou, J., Hao, J., Hatoyama, H., Ben-Nissan, B., Milthorpe, B. & Otsuka, M. 2015, 'Effect of biomimetic zinc-containing tricalcium phosphate (ZnTCP) on the growth and osteogenic differentiation of mesenchymal stem cells', Journal of Tissue Engineering and Regenerative Medicine, vol. 9, no. 7, pp. 852-858.
View/Download from: Publisher's site
Several studies have shown the effectiveness of zinc-tricalcium phosphate (Zn&#8211;TCP) for bone tissue engineering. In this study, marine calcareous foraminifera possessing uniform pore size distribution were hydrothermally converted to Zn&#8211;TCP. The ability of a scaffold to combine effectively with mesenchymal stem cells (MSCs) is a key tissue-engineering aim. In order to demonstrate the osteogenic ability of MSCs with Zn&#8211;TCP, the scaffolds were cultured in an osteogenic induction medium to elicit an osteoblastic response. The physicochemical properties of Zn&#8211;TCP were characterized by XRD, FT&#8211;IR and ICP&#8211;MS. MSCs were aspirated from rat femurs and cultured for 3 days before indirectly placing four samples into each respective well. After culture for 7, 10 and 14 days, osteoblastic differentiation was evaluated using alizarin red S stain, measurement of alkaline phosphatase (ALP) levels, cell numbers and cell viability. XRD and FT&#8211;IR patterns both showed the replacement of CO32&#8211; with PO43&#8211;. Chemical analysis showed zinc incorporation of 5 mol%. Significant increases in cell numbers were observed at 10 and 14 days in the Zn&#8211;TCP group, while maintaining high levels of cell viability (> 90%). ALP activity in the Zn&#8211;TCP group was statistically higher at 10 days. Alizarin red S staining also showed significantly higher levels of calcium mineralization in Zn&#8211;TCP compared with the control groups. This study showed that MSCs in the presence of biomimetically derived Zn&#8211;TCP can accelerate their differentiation to osteoblasts and could potentially be useful as a scaffold for bone tissue engineering.
Hao, J., Acharya, A., Chen, K., Chou, J., Kasugai, S. & Lang, N.P. 2015, 'Novel bioresorbable strontium hydroxyapatite membrane for guided bone regeneration.', Clinical oral implants research, vol. 26, no. 1, pp. 1-7.
Membrane materials have been widely used for guided bone regeneration (GBR). However, due to bio-functional limitation of the current membranes, the ideal resorbable membrane that can stimulate bone regeneration has yet to be developed. This study seeks to investigate the effects of a strontium hydroxyapatite (SrHA)-containing membrane for GBR.Strontium hydroxyapatite powder was synthesized and mixed with gelatin solution to the final concentration of 10 mg/ml (Sr10) and 20 mg/ml (Sr20). Approximately 100-m-thick membranes were fabricated, and the mechanical properties and strontium ion release pattern were analyzed. Rat bone marrow stromal cell (BMSC) responses were investigated in vitro. Bilaterial rat calvarial defects were used in vivo to compare the SrHA membranes against commercially available collagen membranes and evaluated radiologically and histologically.Strontium hydroxyapatite membranes exhibited higher elasticity and strength than the collagen membrane, and slow strontium ion release was also confirmed. No BMSC cytotoxicity was found on the SrHA membranes, and the alkaline phosphatase positively stained area was significantly greater than the collagen membrane at earlier time point. At 4 weeks, both micro-CT and histological analyses revealed that the Sr20 group yielded significantly greater bone formation.The SrHA-containing membrane developed in this study was found to be a biocompatible material that can stimulate BMSC differentiation as well as bone regeneration and maturation in rat calvarial defects at early time point compared with collagen membrane. The best result was observed in Sr20 group, which can be potentially effective for GBR.
Hao, J., Chou, J., Kuroda, S., Otsuka, M., Kasugai, S. & Lang, N.P. 2015, 'Strontium hydroxyapatite in situ gel-forming system - a new approach for minimally invasive bone augmentation.', Clinical oral implants research, vol. 26, no. 5, pp. 581-585.
View/Download from: UTS OPUS
To achieve ideal functional and aesthetic requirements, ridge augmentation is often required before dental implant placement. Bone augmentation (especially vertical), which normally consists of complex and invasive surgeries, still remains challenge. This study seeks to investigate the feasibility of an injectable in situ gel-forming system containing strontium hydroxyapatite (SrHA) and alginate for minimally invasive bone augmentation in a rat calvarial model.SrHA-alginate solution was prepared by mixing SrHA powder with alginate solution (20 mg/mL) to the final concentration of 0.5% (w/v). Each animal received a 200-L single subperiosteal injection of either SrHA-alginate solution or alginate solution. The new bone formation was assessed at 0, 4, and 8 weeks histologically and radiologically.The SrHA-alginate solution materials could form solid gel once injected. As such, no sutures were required to close the injection site. Significantly greater amount of new bone formation was observed in the SrHA-alginate group compared with the alginate group both by micro-CT and by histological section. The newly formed bone in the SrHA-alginate group originated both from the underlying original bone and from the elevated periosteum. A 2.3-fold increase of the vertical bone height was observed in the SrHA-alginate group compared with 1.3-fold increase in the alginate group.Rat calvarial bone augmentation was achieved by a single subperiosteal injection of SrHA-alginate solution without any administration of stem cells or growth factors. The in situ gel-forming material may hold potential therapeutic benefits for local bone augmentation in a minimally invasive manner.
Wang, X., Zakaria, O., Madi, M., Hao, J., Chou, J. & Kasugai, S. 2015, 'Vertical bone augmentation induced by ultrathin hydroxyapatite sputtered coated mini titanium implants in a rabbit calvaria model.', Journal of biomedical materials research. Part B, Applied biomaterials, vol. 103, no. 8, pp. 1700-1708.
View/Download from: Publisher's site
BACKGROUND: The purpose of this study was to evaluate the vertical new bone formation induced by sputtered HA-coated titanium implants (HA-coated) compared with sandblasted acid-etched titanium implants (noncoated) in a rabbit calvarial model. MATERIALS AND METHOD: Twenty HA-coated and 20 noncoated titanium implants were divided equally into four groups as HA-coated implant (HA); noncoated implant (NC); HA-coated implant with membrane (HA/M); noncoated implant with membrane (NC/M). All implants were placed 5 mm above the original bone (OB). Collagen membranes were placed over the implants in HA/M and NC/M groups. The animals were sacrificed at 4 weeks (n=5) and 8 weeks (n=5). Vertical bone height above OB (VBH, mm) and augmented bone area (ABA, mm(2) ) were analyzed histologically and radiographically. RESULTS: At 4 weeks, VBH reached significantly higher level in HA/M group compared with other three groups (p<0.05). At 8 weeks, significant difference was detected between HA/M and NC groups (p<0.05). At 4 and 8 weeks, ABA in HA/M group was significantly larger compared with other three groups (p<0.05). CONCLUSION: The present results indicated that sputtered HA-coated titanium implant together with collagen membrane could be a novel and effective approach for vertical bone augmentation. &copy; 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2014.
Şahin, Y.M., Gündüz, O., Bulut, B., Özyein, L.S., Göke, H., Aaoullari, D., Chou, J., Kayali, E.S., Ben-Nissan, B. & Oktar, F.N. 2015, 'Nano-bioceramic synthesis from tropical sea snail shells (Tiger Cowrie - Cypraea Tigris) with simple chemical treatment', Acta Physica Polonica A, vol. 127, no. 4, pp. 1055-1058.
View/Download from: Publisher's site
In this study several bioceramic materials (i.e. hydroxyapatite, whitlockite) were prepared by using chemical synthesis method from sea snail shells (Tiger Cowrie - Cypraea Tigris), originated from Pacific Ocean. Marine shells usually present aragonite-calcite structures and generally, complicated and pressurized equipment is necessary to convert these structures into bioceramics. Instead of using complicated systems, a basic ultrasonic equipment and simple chemical synthesis method was used in the process. DTA analysis was performed to calculate the required amount of H<inf>3</inf>PO<inf>4</inf> solution in order to set the appropriate stoichiometric ratio of Ca/P equal to 1.667 for HA bioceramic or to 1.5 for -TCP bioceramic in the titration. The prepared batches were sintered at 800&deg;C and 400 &deg;C for hydroxyapatite (HA) and -tri calcium phosphate (-TCP) forms respectively. X-ray diffraction analysis, scanning electron microscopy (SEM) and infrared observations (FTIR) were implemented for both TCP and HA bioceramics. By applying the chemical synthesis with basic ultrasonic equipment, this study proposes a simple way of production for nano-HA/TCP powders from a natural marine sources.
Chou, J. 2014, 'Antibiotic delivery potential of nano and micro porous marine structures derived -TCP spheres for medical applications', Nanomedicine, vol. 1.
View/Download from: UTS OPUS or Publisher's site
Chou, J. 2014, 'Bone regeneration of calvarial defect using marine calcareous-derived beta-tricalcium phosphate macrosphere', Journal of Tissue Engineering, vol. 1.
View/Download from: UTS OPUS or Publisher's site
Yamamoto, M., Nakata, H., Hao, J., Chou, J., Kasugai, S. & Kuroda, S. 2014, 'Osteogenic Potential of Mouse Adipose-Derived Stem Cells Sorted for CD90 and CD105 In Vitro', STEM CELLS INTERNATIONAL.
View/Download from: Publisher's site
Chou, J., Austin, C., Doble, P., Ben-Nissan, B. & Milthorpe, B. 2014, 'Trace elemental imaging of coralline hydroxyapatite by laser-ablation inductively coupled plasma-mass spectroscopy.', Journal of tissue engineering and regenerative medicine, vol. 8, no. 7, pp. 515-520.
The determination of trace element concentrations, as well as their distribution in different biomaterials aimed for clinical applications, is a challenging task in both the areas of biological and materials research. In this research, LA-ICP-MS was employed for image mapping of the trace element distribution in a hydrothermally converted coralline hydroxyapatite material aimed for tissue-scaffolding applications. Quantification using synthetic matrix-matched standards was successfully applied for the determination and distribution of elements of interest, Sr and Mg, that influences the mechanical and biological properties of hydroxyapatite-based bone graft materials. The results showed that the instrument can successfully analyse trace elements and a relatively good image can be produced that identifies their distribution. The LA-ICP-MS method can provide an easy and effective tool, in the field of biomaterials with respect to distribution of trace elements, to better understand tissue-implant interactions, and will open up a new window for in vitro and in vivo analysis and imaging of different tissues and structures.
Chou, J., Valenzuela, S.M., Santos, J., Bishop, D., Milthorpe, B., Green, D.W., Otsuka, M. & Ben-Nissan, B. 2014, 'Strontium- and magnesium-enriched biomimetic -TCP macrospheres with potential for bone tissue morphogenesis.', Journal of tissue engineering and regenerative medicine, vol. 8, no. 10, pp. 771-778.
During the last two decades, biogenic mineral ions have become important additives in treatments for bone regeneration and repair. Prominent among these is strontium, which is a potent suppressor of osteoclast bone resorption. Another is magnesium, which has a key influence in mineralization processes. The shells of benthic foraminiferans, hydrothermally converted into -TCP, have been shown to effectively release a number of bone-promoting drugs at clinically relevant levels. In this study we characterized the effects of converted foraminiferan calcium dissolution and the concomitant release profile of intrinsic strontium and magnesium. We tested the effects of strontium- and magnesium-enriched macrospheres on human osteoblast (SaOS-2) and monocytoid (U937) cell lines, which can be induced to express equivalent phagocytic activities to osteoclasts. On dissolution in a biomimetic physiological solution, the macrospheres released biologically significant quantities of calcium and phosphate ions in the first 18 days. At 3 days, during which biogenic mineral ions are released, the number of U937 osteoclast-like monocyte cells decreased, while 4 days later the osteoblast cell number increased. These results show that strontium and magnesium naturally enriched macrospheres are capable of altering the metabolic activities of the cells regulating bone homeostasis. These unique macrospheres are natural origin bone void filler particles that resorb, and release physiologically significant levels of incorporated strontium, magnesium and calcium, which together make a uniquely multifunctional in situ remedy for bone regeneration and repair and the treatment of bone-wasting diseases.
Macha, I.J., Ozyegin, L., Chou, J., Samur, R., Oktar, F. & Ben-Nissan, B. 2013, 'An alternative synthesis method for di calcium phosphate (monetite) powders from mediterranean mussel (mytilus galloprovincialis) shells', Journal of the Australian Ceramic Society, vol. 49, no. 2, pp. 122-128.
View/Download from: UTS OPUS
Marine species, such as corals, sea shells and nacres, attract special interest in bioceramics field for bone graft, bone cements and drug delivery applications. Most of the marine structures are made up of pure calcium carbonate (calcite or aragonite) with a very small amount of an organic matrix. In the past the most common way to transform these structures to hydroxyapatite was hydrothermal transformation method. This current work introduces a new approach for producing fine powders of calcium phosphates from Mediterranean mussel (Mytilus galloprovincialis) shells. A comparative study was carried out to investigate the differences of these powders under only hot plate heating and hot plate heating together with ultrasonic agitation while H3PO4 was added. The temperature of the hotplate was kept constant at 80 degrees C and then, H3PO4 was added drop wise into the solution for 2 hrs. The mixture was then placed into an oven at 100 degrees C for 24 hrs. They were further calcined at 800 degrees C for 3 hrs. XRD, FTIR. and ICP-MS were used to identify the structure and composition. It was found that the final powders were predominantly monetite, with some tricalcium phosphate as a secondary phase. This relatively simple and efficient method can be easily applied to produce calcium phosphate precursor powders for a range of biomedical applications.
Chou, J., Green, D.W., Singh, K., Hao, J., Ben-Nissan, B. & Milthorpe, B.K. 2013, 'Adipose Stem Cell Coating of Biomimetic -TCP Macrospheres by Use of Laboratory Centrifuge', BioResearch Open Access, vol. 2, no. 1, pp. 67-71.
View/Download from: UTS OPUS or Publisher's site
Biomimetic materials such as coral exoskeletons possess unique architectural structures with a uniform and interconnected porous network that can be beneficial as a scaffold material. In addition, these marine structures can be hydrothermally converted to calcium phosphates, while retaining the original structural properties. The ability of biomaterials to stimulate the local microenvironment is one of the main focuses in tissue engineering, and directly coating the scaffold with stem cells facilitates future potential applications in therapeutics and regenerative medicine. In this article we describe a new and simple method that uses a laboratory centrifuge to coat hydrothermally derived beta-tricalcium phosphate macrospheres from coral exoskeleton with stem cells. In this research the optimal seeding duration and speed were determined to be 1?min and 700 g. Scanning electron micrographs showed complete surface coverage by stem cells within 7 days of seeding. This study constitutes an important step toward achieving functional tissue-engineered implants by increasing our understanding of the influence of dynamic parameters on the efficiency and distribution of stem cell attachment to biomimetic materials and how stem cells interact with biomimetic materials.
Chou, J., Hao, J., Ben-Nissan, B., Milthorpe, B.K. & Otsuka, M. 2013, 'Coral Exoskeletons as a Precursor Material for the Development of Calcium Phosphate Drug Delivery System for Bone Tissue Engineering', Biological & Pharmaceutical Bulletin, vol. 36, no. 11, pp. 1662-1665.
View/Download from: UTS OPUS
With the global rise in aging of populations, the occurrence of osteoporosis will continue to increase. Biomaterial and pharmaceutical scientists continue to develop innovative strategies and materials to address this disease. In this article, we describe a new perspective and approach into the use of coral exoskeletons as a precursor material to synthesize a calcium phosphate-based drug delivery system. Studies detailing the methodology of the conversion methods and the strategies and approach for the development of these novel drug delivery systems are described. Furthermore, in vivo studies in osteoporotic mice using a drug loaded and chemically modified version of the biomimetic delivery system showed significant cortical and cancellous bone increases. These studies support the notion and the rationale for future research and development of the use of coral exoskeletons as materials for drug delivery applications
Chou, J., Ito, T., Otsuka, M., Ben-Nissan, B. & Milthorpe, B.K. 2013, 'Simvastatin-loaded Beta-tCP Drug Delivery System Induces Bone Formation And Prevents Rhabdomyolysis In OVX Mice', Advanced Healthcare Materials, vol. 2, no. 5, pp. 678-681.
View/Download from: UTS OPUS or Publisher's site
Bone formation and regeneration is a prolonged process that requires a slow drug release system to assist in the long-term recovery. A drug-delivery system is developed that allows for the controlled release of simvastin, without exhibiting the side effects associated with high concentrations of simvastatin, and is still capable of inducing constant bone formation.
Chou, J., Ito, T., Otsuka, M., Ben-Nissan, B. & Milthorpe, B.K. 2013, 'The Controlled Release Of Simvastatin From Biomimetic Macrospheres', Key Engineering Materials, vol. 529-530, pp. 461-464.
View/Download from: UTS OPUS or Publisher's site
Simvastatin has been shown to succesfully stimulate bone regeneration and attention has being focussed on developing appropriate delivery carriers for its release. The challenge of deliverying therapeutic concentration of pharmaceutical compunds has bein
Chou, J., Hao, J., Hatoyama, H., Ben-Nissan, B., Milthorpe, B.K. & Otsuka, M. 2013, 'The therapeutic effect on bone mineral formation from biomimetic zinc containing tricalcium phosphate (ZnTCP) in zinc-deficient osteoporotic mice', PLoS One, vol. 8, no. 8, pp. e71821-e71821.
View/Download from: UTS OPUS or Publisher's site
The aim of this study was to evaluate the therapeutic efficacy of biomimetic zinc-containing tricalcium phosphate (ZnTCP) produced by hydrothermally converting calcium carbonate exoskeletons from foraminifera, in the treatment of osteoporotic mice. X-Ray powder diffraction showed crystallographic structures matching JCPDS profile for tricalcium phosphate. Mass spectroscopy used to calculate total composition amount showed similar amount of calcium (5104 &micro;g/g) and phosphate (4104 ppm) after conversion and the presence of zinc (5.18103 &micro;g/g). In vitro zinc release showed no release in PBS buffer and <1% zinc release in 7 days. In vivo evaluation was done in ovariectomized mice by implanting the ZnTCP samples in the soft tissues near the right femur bone for four weeks. Thirty ddY mice (5 weeks old, average weight of 21 g) were divided into six experimental groups (normal, sham, OVX, -TCP, ZnTCP and direct injection of zinc). CT images were taken every two weeks where the bone mineral density (BMD) and bone mineral content (BMC) were calculated by software based on CT images. The ZnTCP group exhibits cortical and cancellous bone growth of 45% and 20% respectively. While sham, OVX and -TCP suffered from bone loss. A correlation was made between the significant body weight increase in ZnTCP with the significant increase in plasma zinc level compared with OVX. The presented results indicate that biomimetic ZnTCP were effective in preventing and treating bone loss in osteoporotic mice model.
Green, D.W., Padula, M., Santos, J., Chou, J., Milthorpe, B.K. & Ben-Nissan, B. 2013, 'A Therapeutic Potential for Marine Skeletal Proteins in Bone Regeneration.', Marine Drugs, vol. 11, no. 4, pp. 1203-1220.
View/Download from: UTS OPUS or Publisher's site
A vital ingredient for engineering bone tissue, in the culture dish, is the use of recombinant matrix and growth proteins to help accelerate the growth of cultivated tissues into clinically acceptable quantities. The skeletal organic matrices of calcifying marine invertebrates are an untouched potential source of such growth inducing proteins. They have the advantage of being ready-made and retain the native state of the original protein. Striking evidence shows that skeleton building bone morphogenic protein-2/4 (BMP) and transforming growth factor beta (TGF-) exist within various marine invertebrates such as, corals. Best practice mariculture and the latest innovations in long-term marine invertebrate cell cultivation can be implemented to ensure that these proteins are produced sustainably and supplied continuously. This also guarantees that coral reef habitats are not damaged during the collection of specimens. Potential proteins for bone repair, either extracted from the skeleton or derived from cultivated tissues, can be identified, evaluated and retrieved using chromatography, cell assays and proteomic methods. Due to the current evidence for bone matrix protein analogues in marine invertebrates, together with the methods established for their production and retrieval there is a genuine prospect that they can be used to regenerate living bone for potential clinical use.
Chou, J., Hao, J., Kuroda, S., Bishop, D.P., Ben-Nissan, B., Milthorpe, B.K. & Otsuka, M. 2013, 'Bone regeneration of rat tibial defect by zinc-tricalcium phosphate (Zn-TCP) from porous Foraminifera carbonate macrospheres', Marine Drugs, vol. 11, no. 12, pp. 5148-5158.
View/Download from: UTS OPUS or Publisher's site
Foraminifera carbonate exoskeleton was hydrothermally converted to biocompatible and biodegradable zinc-tricalcium phosphate (Zn-TCP) as an alternative biomimetic material for bone fracture repair. Zn-TCP samples implanted in a rat tibial defect model for eight weeks were compared with unfilled defect and beta-tricalcium phosphate showing accelerated bone regeneration compared with the control groups, with statistically significant bone mineral density and bone mineral content growth. CT images of the defect showed restoration of cancellous bone in Zn-TCP and only minimal growth in control group. Histological slices reveal bone in-growth within the pores and porous chamber of the material detailing good bone-material integration with the presence of blood vessels. These results exhibit the future potential of biomimetic Zn-TCP as bone grafts for bone fracture repair.
Macha, I.J., Ozyegin, L.S., Chou, J., Samur, R., Oktar, F.N. & Ben-Nissan, B. 2013, 'An Alternative Synthesis Method for Di Calcium Phosphate (Monetite) Powders from Mediterranean Mussel (Mytilus galloprovincialis) Shells.', Journal of the Australian Ceramics Society, vol. 49, no. 2, pp. 122-128.
View/Download from: UTS OPUS
Marine species, such as corals, sea shells and nacres, attract special interest in bioceramics field for bone graft, bone cements and drug delivery applications. Most of the marine structures are made up of pure calcium carbonate (calcite or aragonite) with a very small amount of an organic matrix. In the past the most common way to transform these structures to hydroxyapatite was hydrothermal transformation method. This current work introduces a new approach for producing fine powders of calcium phosphates from Mediterranean mussel (Mytilus galloprovincialis) shells. A comparative study was carried out to investigate the differences of these powders under only hot plate heating and hot plate heating together with ultrasonic agitation while H3PO4 was added. The temperature of the hotplate was kept constant at 80 &deg;C and then, H3PO4 was added drop wise into the solution for 2 hrs. The mixture was then placed into an oven at 100 &deg;C for 24 hrs. They were further calcined at 800 &deg;C for 3 hrs. XRD, FTIR and ICP-MS were used to identify the structure and composition. It was found that the final powders were predominantly monetite, with some tricalcium phosphate as a secondary phase. This relatively simple and efficient method can be easily applied to produce calcium phosphate precursor powders for a range of biomedical applications.
Chou, J., Ito, T., Bishop, D., Otsuka, M., Ben-Nissan, B. & Milthorpe, B. 2013, 'Controlled release of simvastatin from biomimetic -TCP drug delivery system.', PloS one, vol. 8, no. 1, p. e54676.
View/Download from: UTS OPUS
Simvastatin have been shown to induce bone formation and there is currently a urgent need to develop an appropriate delivery system to sustain the release of the drug to increase therapeutic efficacy whilst reducing side effects. In this study, a novel drug delivery system for simvastatin by means of hydrothermally converting marine exoskeletons to biocompatible beta-tricalcium phosphate was investigated. Furthermore, the release of simvastatin was controlled by the addition of an outer apatite coating layer. The samples were characterized by x-ray diffraction analysis, fourier transform infrared spectroscopy, scanning electron microscopy and mass spectroscopy confirming the conversion process. The in-vitro dissolution of key chemical compositional elements and the release of simvastatin were measured in simulated body fluid solution showing controlled release with reduction of approximately 25% compared with un-coated samples. This study shows the potential applications of marine structures as a drug delivery system for simvastatin.
Chou, J., Ben-Nissan, B., Green, D.D., Valenzuela, S. & Kohan, L. 2011, 'Targeting And Dissolution Characteristics Of Bone Forming And Antibacterial Drugs By Harnessing The Structure Of Microspherical Shells From Coral Beach Sand', Advanced Engineering Materials, vol. 13, no. 1-2, pp. 93-99.
View/Download from: UTS OPUS or Publisher's site
Pharmaceutical drugs for the treatment of metabolic bone diseases lead to a number of side effects due to the their uncontrollable dispersion throughout the body.([1]) Therefore, many groups directed their research to develop devices that are targeted to
Chou, J., Green, D.W. & Ben-Nissan, B. 2010, 'New slow drug delivery materials and systems for biomedical applications', Materials Australia, vol. 43, no. 3, pp. 37-41.
View/Download from: Publisher's site
Chou, J., Shimmon, R. & Ben-Nissan, B. 2009, 'Bisphosphonate determination using H-1-NMR spectroscopy for biomedical applications', Journal Of Tissue Engineering And Regenerative Medicine, vol. 3, no. 2, pp. 92-96.
View/Download from: UTS OPUS or Publisher's site
Bisphosphonate is known to be a very active drug in the treatment of osteoporosis and bone regeneration. A new method has been developed, utilizing nuclear magnetic resonance spectroscopy to identify and measure the amount of bisphosphonate in solution. A standard reference with similar functional group to that of the bisphosphonate was chosen and applied in the experimentation. The results showed that the use of nuclear magnetic resonance spectroscopy (H-1-NMR) in determining the solvent residues of various pharmaceutical drugs has proved to be effective. Unlike chromatography, it is possible to use a universal reference standard as an internal standard assayed by quantitative NMR. Using the same theory, this method is capable of both identifying and quantifying the bisphosphonate in various solutions. This paper is the first publication showing this unique measurement method, which can be used in a range of pharmaceutical and biomedical applications.
Chou, J., Ben-Nissan, B., Choi, A.H., Wuhrer, R. & Green, D. 2007, 'Conversion of coral sand to calcium phosphate for biomedical applications', Journal of the Australasian Ceramic Society, vol. 43, no. 1, pp. 44-48.
View/Download from: UTS OPUS
Coral sand grains were analysed using simultaneous differential thermogravimetric analysis (DTA/TGA) Fourier-Transform infrared spectroscopy (FTIR), x-ray diffraction (XRD) and environmental scanning electron microscopy (ESEM). These techniques were performed to confirm the characteristics and properties as well as the composition of the coral sand grains. Imaging of the full surface topography were conducted inthe ESEM. After characterisation coral sand grains were treated for impurities and organic materials were subsequently removed. The materials were then converted to calcium phosphates utilising hydrothermal treatment. The results have shown that the coral sand grains were composed of calcium carbonate with a network of uniform inner porous structure. The ESEM has provided valuable information through the imaging of the samples which in turn allowed a comparison of the pore sizes before and after the hydrothermal treatment. The current study shows that the coral sand to be a promising source of converted calcium carbonate to calium phosphates for biomedical applications.
Lewis, K.C., Choi, A.H., Chou, J. & Ben-Nissan, B. 2007, 'Nanoceramics in medical applications', Materials Australia, vol. 40, no. 3, pp. 32-34.