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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)
Lecturer, School of Medical and Molecular Biosciences
Core Member, Centre for Health Technologies
BSc in Nanotechnology, BSC in Honours, Grad Cert PM (USyd), Doctor of Philosophy
 
Phone
+61 2 9514 1729
Room
CB07.05.21

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)

Book Chapters

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.
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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).

Conference Papers

Green, D., Padula, M.P., Santos, J., Chou, J., Milthorpe, B.K. & Ben-Nissan, B. 2013, 'A new role for marine skeletal proteins in regenerative orthopaedics', Bioceramics, Fukuoka, Japan, October 2012 in Key Engineering Materials (Volumes 529 - 530) bioceramics 24, ed Kunio Ishikawa and Yukihide Iwamoto, Scientific.net, USA, pp. 654-659.
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.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.
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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.
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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
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.
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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., 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, p. e71821.
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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 g/g) and phosphate (4104 ppm) after conversion and the presence of zinc (5.18103 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.P., 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.
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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., Ito, T., Bishop, D.P., Otsuka, M., Ben-Nissan, B. & Milthorpe, B.K. 2013, 'Controlled Release of Simvastatin from Biomimetic -TCP Drug Delivery System', PLoS One, vol. 8, no. 1, pp. e54676-1-e54676-6.
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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., 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.
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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.
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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., 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.
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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.
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.
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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.
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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.
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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.
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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.

Other research activity

Chou, J., Valenzuela, S., Naidoo, J., Bishop, D.P., Milthorpe, B.K., Green, D.W., Otsuka, M. & Ben-Nissan, B. 2014, 'Strontium- and magnesium-enriched biomimetic beta-TCP macrospheres with potential for bone tissue morphogenesis', Journal of Tissue Engineering and Regenerative Medicine, John Wiley and Sons, USA.
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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 18days. At 3days, during which biogenic mineral ions are released, the number of U937 osteoclast-like monocyte cells decreased, while 4days 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.