Fabrication of porous bioceramics for bone tissue applications using luffa cylindrical fibres (LCF) as template

Abstract

Three-dimensionally ordered macroporous biomaterials containing hydroxyapatite were synthesized using natural luffa cylindrical fibres (with diameter of 100-400 µm) as templates. The preliminary evaluation of this novel method for production of porous bioceramics showed promising potential applications in bone tissue engineering. The produced bioceramics were subjected to microstructural, physical, mechanical, and in vitro characterisation. Mercury intrusion porosimetry, supported by SEM analysis, showed the presence of bimodal porosity (smaller pores with diameters of 10 to 30 µm and cylindrical macropores with diameters from 100 to 400 µm) and 60% of the interconnected porosity. These porous calcium phosphate ceramics proved to be bioactive and exhibited mechanical properties comparable to those of natural spongy bones with compressive strength up to 3 MPa and elastic modulus in compression around 0.05 GPa. In vitro characterization of the porous ceramics showed cells attaching to the apatite crystals that make up the scaffold matrix. Cell adhesion resulted in elongated and highly stretched cells within the macropores with focal adhesion points on the scaffolds. Moreover, the cells adhered to the calcium phosphate cement (CPC) and developed cytoplasmic extensions as shown by SEM imagery. Their proliferation in the scaffolds in culture demonstrates that the scaffold architecture is suitable for Mesenchymal stem cells seeding and growth.

Effects of the full-scale substitution of strontium for calcium on the microstructure of brushite: (CaxSr1–x)HPO4.nH2O system

“…Calcium phosphate (CaP) phases and minerals are used in a wide range of clinical, environmental and engineering applications. They are commonly used as substitutes in bones because their biochemical properties make them suitable for medical applications (Alshaaer et al, 2017;Neves et al, 2017;Radwan et al, 2020) and they are chemically and structurally similar to the mineral phase of bone tissues. Different phases of CaPs serve as precursors in the preparation of biocements and bioceramics, showing potential in the field of advanced materials research and technology (Alshaaer et al, 2013(Alshaaer et al, , 2017(Alshaaer et al, , 2020.…”

“…In general, they show low toxicity, high bioactivity and good biocompatibility. In addition, they exhibit acceptable biodegradable rates and can bond directly to bones given their mineralogical structure and chemical composition resembling the mineral phases of teeth and natural bone (Alshaaer et al, 2013(Alshaaer et al, , 2017Khalifehzadeh & Arami, 2020). Therefore, CaPs are excellent candidates for bone tissue engineering, drug delivery and bonerelated disease treatment (Shyong et al, 2018;Khalifehzadeh & Arami, 2020).…”

“…Brushite is an important precursor of several bone cements and bioceramics (Alshaaer et al, 2013(Alshaaer et al, , 2017. The novelty of this research lies in the study of the effects of the full-scale replacement of Ca by Sr as one of the most important elements in biomaterials (Kruppke et al, 2020) starting from pure brushite.…”

“…They are commonly used as substitutes in bones because their biochemical properties make them suitable for medical applications (Alshaaer et al , 2017; Neves et al , 2017; Radwan et al , 2020) and they are chemically and structurally similar to the mineral phase of bone tissues. Different phases of CaPs serve as precursors in the preparation of biocements and bioceramics, showing potential in the field of advanced materials research and technology (Alshaaer et al , 2013, 2017, 2020). In general, they show low toxicity, high bioactivity and good biocompatibility.…”

Novel calcium phosphate/PCL graded samples: Design and development in view of biomedical applications

“…It is now widely accepted that a high volume fraction of interconnected macroporosity is needed to favour bone colonization and vascularization of the implants through circulation of fluids and cells into the scaffolds [16][17][18]. The suitable pore size range is still discussed in literature [19,20]: macropores with a size in the range 100-500 μm are reported by most authors [21,22,23]. The presence of smaller pores with a size ranging from 1 to 30 µm, is also important to favour bone cell attachment [21].…”