Co-reporter:Huan Zhou, Mengmeng Yang, Saisai Hou, Linhong Deng
Materials Science and Engineering: C 2017 Volume 71() pp:439-445
Publication Date(Web):1 February 2017
DOI:10.1016/j.msec.2016.10.040
•Mesoporous HA is hydrothermally prepared using hexametaphosphate.•Mesoporous HA with tailored physiochemical properties are prepared using polyphenols.•Polyphenols make mesoporous HA more pH-responsive for Dox delivery.Mesoporous hydroxyapatite (HA) nanoparticles with high surface area have been widely investigated for drug delivery. Herein we report a facile and simple strategy for the preparation of such materials using hexametaphosphate salt as inorganic phosphorus source. In the hydrothermal processing, hexametaphosphate plays an important role in the formation of mesoporous structure. The as-prepared mesoporous HA nanoparticles can be candidates for pH-responsive anticancer drug delivery by using doxorubicin (Dox) as a model drug. Furthermore, modification of these mesoporous HA nanoparticles using tea polyphenols is attempted. The presence of tea polyphenols in the HA synthesis processing result in mesoporous HA nanoparticles with tailored morphology and properties, making them more pH-sensitive for drug delivery. Both hexametaphosphate and tea polyphenols can be potential chemical sources in synthesizing mesoporous HA.
Co-reporter:Huan Zhou, Saisai Hou, Mingjie Zhang, Hong Chai, Yang Liu, Sarit B Bhaduri, Lei Yang, Linhong Deng
Ceramics International 2016 Volume 42(Issue 9) pp:11032-11038
Publication Date(Web):July 2016
DOI:10.1016/j.ceramint.2016.03.246
Abstract
Biphasic calcium phosphate (BCP) compositions consisting of β-tricalcium phosphate (β-TCP) and calcium pyrophosphate (CPP) are potential biodegradable ceramics for bone regeneration. The present work demonstrates the formation of such dense ceramics by first preparing the precursors of nano-sized, amorphous, and equiaxed calcium pyrophosphate particles, and then sintering the precursors at 900 °C to transform them into desired BCP. However, if the complex of calcium tripolyphosphate was used, only CPP could be generated. It was also observed that the incorporation of Mg2+ had several effects on the resulting products including: (1) promoting the generation of meso-porous precipitates; (2) favoring the formation of β-TCP instead of CPP; (3) reducing the grain size and increasing the density of the sintered ceramics, and (4) enhancing the negative electric charge of the BCP surface. Thus, the as-prepared BCP ceramics can serve as potential bone substitute materials in orthopedic applications.
Co-reporter:Huan Zhou, Mengmeng Yang, Mingjie Zhang, Saisai Hou, Shiqin Kong, Lei Yang, Linhong Deng
Ceramics International 2016 Volume 42(Issue 15) pp:16671-16676
Publication Date(Web):15 November 2016
DOI:10.1016/j.ceramint.2016.07.101
Abstract
Chinese mystery snail is a popular aquatic food in China, resulting in tonnes of shells as waste every year. In present work, these shells were recycled as calcium source to prepare HA. Initially, shells were found to decompose within 860 °C to porous CaO. The calcined shells were then hydrothermally utilized to synthesize HA with the help of different phosphate sources (PO43−, P2O74−, P3O105−, and P6O186−). Under hydrothermal processing, condensed phosphate ions could be hydrolyzed into PO43− to react with Ca2+. The prepared HA was subsequently characterized by XRD, FTIR, SEM, EDX and TEM. It was found condensed phosphates could result in significant changes to the morphology of HA in comparison to orthophosphate. In particular, P6O186− related HA appeared to be mesoporous. The cytocompatibility of different phosphate source related HA was also investigated.
Co-reporter:Huan Zhou, Shiqin Kong, Sarit B. Bhaduri, Linhong Deng
Materials Letters 2015 Volume 156() pp:79-81
Publication Date(Web):1 October 2015
DOI:10.1016/j.matlet.2015.04.116
•A method to produce CaPs with negative zeta potential using SCPP as precursor.•The SCPP was precipitated as microspheres with nanoporous structure.•Depending on the experiment environment, the products can be HA, CPP or DCPA.Calcium phosphates with negative zeta potential belong to a type of materials favoring apatite nucleation, bone regeneration, as well as osseointegration. Unfortunately, there are limited options to produce such materials. The present work demonstrates a simple but versatile method to prepare calcium phosphates with negative zeta potential using sodium calcium polyphosphate as a precursor. The resulting products can be hydroxyapatite, calcium pyrophosphate or monetite, depending on the relevant experimental conditions. Both hydroxyapatite and calcium pyrophosphate were composed of nanoparticles. However, the as-prepared monetite was micro-plates with nanoporous surface structures. Such calcium phosphates may have great potential in bone tissue engineering applications.
Co-reporter:Huan Zhou, Timothy J.F. Luchini, Nariman Mansouri Boroujeni, Anand K. Agarwal, Vijay K. Goel, Sarit B. Bhaduri
Materials Science and Engineering: C 2015 50() pp: 45-51
Publication Date(Web):
DOI:10.1016/j.msec.2015.01.099
Co-reporter:Huan Zhou, Shiqin Kong, Yan Pan, Zhiguo Zhang, Linhong Deng
Materials Science and Engineering: C 2015 Volume 56() pp:174-180
Publication Date(Web):1 November 2015
DOI:10.1016/j.msec.2015.06.032
•Strontium doped calcium phosphate coating is deposited with microwave irradiation.•Increase of strontium reduces coating roughness and results in finer nucleus size.•Proliferation and differentiation of osteoblasts depend on doped strontium content.Strontium has been shown to be a beneficial dopant to calcium phosphates when incorporated at nontoxic level. In the present work we studied the possibility of solution derived doping strontium into calcium phosphate coatings on titanium alloy Ti6Al4V based implants by a recently reported microwave-assisted method. By using this method strontium doped calcium phosphate nuclei were deposited to pretreated titanium alloy surface dot by dot to compose a crack-free coating layer. The presence of strontium in solution led to reduced roughness of the coating and finer nucleus size formed. In vitro study found that proliferation and differentiation of osteoblast cells seeded on the coating were influenced by strontium content in coatings, showing an increasing followed by a decreasing behavior with increasing substitution of calcium by strontium. It is suggested that this new microwave-assisted strontium doped calcium phosphate coatings may have great potential in implant modification.
Co-reporter:Huan Zhou, Vijay K. Goel, Sarit B. Bhaduri
Materials Letters 2014 Volume 125() pp:96-98
Publication Date(Web):15 June 2014
DOI:10.1016/j.matlet.2014.03.130
•A microwave assisted coating process for biopolymer surface modification.•A rapid microwave assisted chemical etching for PEEK.•Both etching and coating process take only a few minutes.The objective of this work is to present the possibility of modifying surface of orthopedic biopolymers such as polyetheretherketone (PEEK) using a microwave assisted apatite coating technique. In spite of many of PEEK׳s significant attributes, this material lacks the ability to osseointegrate with the surrounding bone. Hence a bioactive coating is suggested. The coating process described herein exposes surface activated PEEK to a microwave irradiated concentrated biomimetic fluid for a few minutes. The resulting coating is characterized and evaluated for potential biomedical applications.
Co-reporter:Huan Zhou;Timothy J. F. Luchini;An K. Agarwal;Vijay K. Goel;Sarit B. Bhaduri
Journal of Biomedical Materials Research Part B: Applied Biomaterials 2014 Volume 102( Issue 8) pp:1620-1626
Publication Date(Web):
DOI:10.1002/jbm.b.33149
Abstract
In this paper, we reported the results of our efforts in developing DCPA/nanosilica composite orthopedic cement. It is motivated by the significances of DCPA and silicon in bone physiological activities. More specifically, this paper examined the effects of various experimental parameters on the properties of such composite cements. In this work, DCPA cement powders were synthesized using a microwave synthesis technique. Mixing colloidal nanosilica directly with synthesized DCPA cement powders can significantly reduce the washout resistance of DCPA cement. In contrast, a DCPA–nanosilica cement powder prepared by reacting Ca(OH)2, H3PO4 and nanosilica together showed good washout resistance. The incorporation of nanosilica in DCPA can improve compressive strength, accelerate cement solidification, and intensify surface bioactivity. In addition, it was observed that by controlling the content of NaHCO3 during cement preparation, the resulting composite cement properties could be modified. Allowing for the development of different setting times, mechanical performance and crystal features. It is suggested that DCPA–nanosilica composite cement can be a potential candidate for bone healing applications. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B, 102B: 1620–1626, 2014.
