Hydroxyapatite Bioceramics Research Articles

Alpha-calcium sulfate hemihydrate incorporated with tri-calcium phosphate and hydroxyapatite bioceramics as potential scaffold for bone regeneration

The development of artificial grafts, including biodegradable materials and non-biodegradable ones, for bone regeneration is a significant advance in the field of biomaterial science. Notably, bioceramics such as calcium sulfate hemihydrate and calcium phosphates have attracted extensive attention from researchers due to their natural bone-like composition. However, some requirements related to mechanical properties, resorption ability, osteoinduction and osteoconduction of each bioceramics have not been effectively controlled to make them ideal materials for bone regeneration applications. In this study, composites of β-tricalcium phosphate, hydroxyapatite, and α-calcium sulfate hemihydrate (β-TCP/HA/α-CSH) were synthesized using wet mixing method in order to create a template that degrades in sync with bone growth, offer sufficient mechanical strength during healing process, and has appropriate setting time for precise surgical application. The β-TCP/HA compositional phase with the ratio of 80/20 (% in weight) would be used for the entire study meanwhile the influence of α-CSH on the behaviour of β-TCP/HA/α-CSH composites would be investigated. The successful preparation of β-TCP/HA/α-CSH composite was evaluated by FTIR, XRD, and SEM. In vitro testing has further demonstrated the commendable biodegradability of β-TCP/HA/α-CSH composites and its ability for cell adhesion and migration, suggesting that β-TCP/HA/α-CSH composites would be a promising biomaterial for bone engineering.

Design of biphasic Fe and Zn doped hydroxyapatite: Novel strategy for combating osteomyelitis infections

Hydroxyapatite (HA) bioceramics are widely used materials for orthopaedic applications, offering enhanced cellular adhesion and differentiation. However, the lack of antibacterial features makes the HA biomaterials prone to bacterial infections in in-vivo conditions. The osteomyelitis-like conditions are often treated with prolonged doses of antibiotics and may require surgical removal. Such problems can be tackled by inducing the antibacterial characteristics in the biomaterials which prevent such infections. Various research studies have been conducted to improve the mechanical and antibacterial characteristics of biomaterials like HA through doping. The present study focuses on the synthesis, characterization, and antibacterial study of Zn and Fe doped HA (ZFHAp) for application in the treatment of osteomyelitis. Response Surface Methodology (RSM) based Central Composite Design (CCD) approach was used to optimize the process parameters using the Design Expert software. The analyses indicated the presence of Calcium Iron Hydrogen Phosphate (CIHP) and Parascholzite (PS) as major phases. The optimized experimental conditions were estimated as 0.09 M Zn and 0.04 M Fe at 65 °C, corresponding to 71.29 % and 28.71 % of the CIHP and PS phases, respectively. The synthesized nanopowder showed mixed morphology comprising spherical and rod-shaped particles due to biphasic composition. The ZFHAp sample showed a broad-spectrum antibacterial activity, with IC50 values of 4.02 mg/ml and 4.79 mg/ml against E. coli and S. aureus, respectively. The optimized sample showed excellent biocompatibility with the osteoblast-like cells (MG-63) with improved biomineralization properties. The antibacterial and osteoinductive characteristics of the synthesized biphasic Fe and Zn doped HA suggest its potential application against osteomyelitis-related conditions.

Silver-blend hydroxyapatite bio-ceramics for enhanced photocatalytic degradation of methylene blue

Silver-blend hydroxyapatite bio-ceramics for enhanced photocatalytic degradation of methylene blue

In-situ preparation of nitrogen-doped porous hydroxyapatite bioceramic with high carbonate content using nitrocellulose self-propagating sintering

Nitrocellulose (NC) has important applications in both military and civilian fields. However, due to expiration dates, declining quality, etc., more than 100,000 tons of NC are disposed of per year, mostly by incineration, which is a great waste of resources. In this paper, using NC's characteristics of self-sustaining combustion, high gas yield and no residue, a nitrogen-doped porous hydroxyapatite bioceramic with high carbonate content (NPC-HA) was prepared in situ by a self-propagating sintering method. The C content of NPC-HA reaches 6%, and the N content is 0.34%. After treatment at the optimal temperature of 1000 °C, NPC-HA maintains the basic morphology of hydroxyapatite (HA) needle-like particles. Moreover, these particles are fused, forming a nest-like pore structure that disperses stress, producing a significant increase in compressivestrength. CCK-8 results show that NPC-HA has excellent biocompatibility due to nitrogen doping, high carbonate content and abundant pore structures. The method not only effectively utilizes NC industrial waste but also significantly reduces the sintering temperature of HA ceramics from the usual 1200 °C to 1000 °C. Therefore, it is a green preparation technology for porous HA bioceramics with considerable promise for wide industrial use.

Bovine hydroxyapatite/3Y-TZP bioceramic: Aligning 3Y-TZP content with sintering parameters

This study aimed to produces and characterize bovine hydroxyapatite (HA) bioceramic with 3Y-TZP addition and analyze different sintering curves. HA was extracted from bovine bones and nanoparticulated. HA discs (0, 1, 5 and 10 wt% 3Y-TZP) were subjected to uniaxial and isostatic pressing. Dilatometry analysis was performed and the groups were sintered using 3 different firing curves (conventional, 1300 °C; 2-step, 1292 °C; 2-step, 1420 °C). The samples were analyzed by X-ray diffraction (XRD), biaxial flexural strength (BFS), Vickers microhardness (VH) and Field emission scanning electron microscopy (FE-SEM). The dilatometry results signaled the need for sintering optimization in groups added with 3Y-TZP. XRD demonstrated the characteristic crystallographic peaks of HA in the pure groups and with 1% 3Y-TZP, and decomposition of HA into β-TCP and formation of calcium zirconate in the groups with 5 and 10% 3Y-TZP. Considering each composition, the groups of pure HA (131.3 ± 13.5 MPa; 401 ± 12.7 GPa) sintered by the conventional curve and HA+1%3Y-TZP (145 ± 8.6 MPa; 507 ± 47.9 GPa), HA+5%3Y-TZP (68.1 ± 14.2 MPa; 183 ± 9.8 GPa) and HA+10%3Y-TZP (55.6 ± 5.1 MPa; 96.1 ± 7.64 GPa) sintered by the 2-step curve at 1420 °C, combined the best BFS and VH results. The addition of 1 wt% 3Y-TZP and optimization in the sintering process improved the mechanical and microstructural properties of HA bioceramics and maintenance of its crystalline characteristics. Refinement in material processing is necessary for the future use of this bioceramic in dentistry.

Advancing Osteoporotic Bone Regeneration Through Tailored Tea Polyphenols Functionalized Micro‐/Nano‐ Hydroxyapatite Bioceramics

AbstractEfforts to develop advanced bone substitutes for effective bone regeneration in substantial defects have led to the fabrication of tissue‐engineered scaffolds. These scaffolds, featuring hierarchical structures, specific chemical compositions, and functional qualities, are essential in mimicking native bone tissue. Inspired by the biomineralization process, hydrothermal treatment is used to synthesize micro‐/nano‐hydroxyapatite bioceramics functionalized with tea polyphenols (TP‐nwHA), closely resembling the structure of bone‐like apatite induced by hydroxyapatite bioceramics in vivo. The in vitro results demonstrate TP‐nwHA's superior biocompatibility, enhancing cell proliferation and adhesion. Furthermore, TP‐nwHA scaffolds significantly influence mesenchymal stem cells, promoting osteogenic differentiation while inhibiting osteoclastogenic differentiation. The upregulation of osteogenic proteins BMP2 and ITGB1, along with the downregulation of osteoclastic proteins FGF21 and IGFBP1, demonstrate the synergistic effect of the biomimetic structure and polyphenols on the activation of the MAPK signaling pathway. In vivo, TP‐nwHA showe early angiogenic capabilities, leading to improved bone regeneration in critical‐size femoral bone defects in osteoporotic rats. Histological staining confirms the complete bridging of defects with new bone tissue in the TP‐nwHA group, and nanoindentation tests indicate the formation of mature mineralized bone tissue. Collectively, these findings suggest a novel strategy for fabricating bone‐mimicking constructs with potential applications in disease modeling.

Construction of multileveled and oriented micro/nano channels in Mg doped hydroxyapitite bioceramics and their effect on mimicking mechanical property of cortical bone and biological performance of cancellous bone

Drawing on the structure and components of natural bone, this study developed Mg-doped hydroxyapatite (Mg-HA) bioceramics, characterized by multileveled and oriented micro/nano channels. These channels play a critical role in ensuring both mechanical and biological properties, making bioceramics suitable for various bone defects, particularly those bearing loads. Bioceramics feature uniformly distributed nanogrooves along the microchannels. The compressive strength or fracture toughness of the Mg-HA bioceramics with micro/nano channels formed by single carbon nanotube/carbon fiber (CNT/CF) (Mg-HA(05-CNT/CF)) are comparable to those of cortical bone, attributed to a combination of strengthened compact walls and microchannels, along with a toughening mechanism involving crack pinning and deflection at nanogroove intersections. The introduction of uniform nanogrooves also enhanced the porosity by 35.4 %, while maintaining high permeability owing to the capillary action in the oriented channels. This leads to superior degradation properties, protein adsorption, and in vivo osteogenesis compared with bioceramics with only microchannels. Mg-HA(05-CNT/CF) exhibited not only high strength and toughness comparable to cortical bone, but also permeability similar to cancellous bone, enhanced cell activity, and excellent osteogenic properties. This study presents a novel approach to address the global challenge of applying HA-based bioceramics to load-bearing bone defects, potentially revolutionizing their application in tissue engineering.

Synthesis of Hydroxyapatite Bioceramic from Cuttlefish Shell Waste and Coral Using Microwave Hydrothermal

Synthesis of Hydroxyapatite Bioceramic from Cuttlefish Shell Waste and Coral Using Microwave Hydrothermal

Nano-/micro-scaled hydroxyapatite ceramic construction and the regulation of immune-associated osteogenic differentiation.

Hydroxyapatite (HA) bioceramic is a promising substitute for bone defects, and the surface properties are major factors that influence bioactivity and osteoinductivity. In this study, two kinds of HA bioceramics with nanoscale (n-HA) and microscale (m-HA) surface topography were designed to mimic the natural bone, thus enhancing the stimulation of osteogenic differentiation and revealing the potential mechanism. Compared to m-HA, n-HA owned a larger surface roughness, a stronger wettability, and reduced hardness and indentation modulus. Based on these properties, n-HA could maintain the conformation of vitronectin better than m-HA, which may contribute to higher cellular activities and a stronger promotion of osteogenic differentiation of mesenchymal stem cells (MSCs). Further RNA sequencing analysis compared the molecular expression between n-HA and m-HA. Six hundred twenty-seven differentially expressed genes were identified in MSCs, and 17 upregulated genes and 610 downregulated genes were included when n-HA compared to m-HA. The GO cluster analysis and enriched Kyoto encyclopedia of genes and genome signaling pathways revealed a close correlation with the immune process in both upregulated (chemokine signaling pathway and cytokine-cytokine receptor interaction) and downregulated pathways (osteoclasts differentiation). It suggested that the nanoscale surface topography of HA enhanced the osteoinductivity of MSCs and could not be separated from its regulation of immune function and the retention of adsorbed protein conformation.

Autophagy mediates osteoporotic bone regeneration induced by micro-/nano-structured modification on hydroxyapatite bioceramics

Autophagy mediates osteoporotic bone regeneration induced by micro-/nano-structured modification on hydroxyapatite bioceramics

Effect of different HA/β-TCP coated 3D printed bioceramic scaffolds on repairing large bone defects in rabbits.

Treatment of large segmental bone defects is still a major clinical challenge, and bone grafting is the main method. The development of novel bone graft substitutes will help solve this problem. Porous bioceramics hydroxyapatite (HA) scaffolds coated with different ratios of HA/β-tricalcium phosphate (β-TCP) were prepared by 3D printing. The scaffolds were sampled and tested in large segmental bone defect rabbit models. X-ray, micro-computed tomography (CT), hematoxylin and eosin (HE) staining, Van-Gieson staining, and type I collagen staining were performed to find the best scaffolds for large segmental bone defect treatment. The average length, diameter, compressive strength, and porosity of the bioceramics scaffolds were 15.05 ± 0.10mm, 4.98 ± 0.06mm, 11.11 ± 0.77MPa, and 54.26 ± 5.38%, respectively. Postoperative lateral radiographs suggested the scaffold group got better bone healing and stability than the blank group. Micro-CT showed new bones grew into the scaffold from the two ends of the fracture along the scaffold and finally achieved bony union. The new bone volume around the scaffolds suggested the 3:7 HA/β-TCP-coated bioceramic scaffolds were more favorable for the healing of large segmental bone defects. The results of HE, Van-Gieson, and type I collagen staining also suggested more new bone formation in 3:7 HA/β-TCP-coated bioceramic scaffolds. 3:7 HA/β-TCP-coated porous bioceramics scaffolds are more conducive to the repair of large bone defects in rabbits. The results of this study can provide some reference and theoretical support in this area.

Structure and properties of biogenic hydroxyapatite bioceramics modified by graphene-like structures

Today bone tissue engineering is one of the most used technologies for treat bones injure. Materials containing hydroxyapatite and graphene have received much attention recently. The aim of this study was preparation of biogenic hydroxyapatite bioceramics modified by graphene-like structures investigation effect of graphene on the structure and properties of material. Biogenic hydroxyapatite bioceramics modified by graphene-like structures were successfully prepared by chemical vapor deposition (CVD) method. Subsequently, microstructure, composition, specific surface area, skeleton density, resorption rate in physiological solution and cytotoxicity were evaluated. XRD, IR spectroscopy, micro-Raman spectroscopy and SEM proved graphene oxide’s formation on biogenic hydroxyapatite as well as on silica single crystal for comparison. Although the coating of graphene-like structures on biogenic hydroxyapatite bioceramics reduces the specific surface area, it allows to 4 times increase resorption rate of biogenic hydroxyapatite bioceramics in physiological solution and does not affect the overall assessment of the cytotoxicity. MTT assay established non-cytotoxic effect and indicated a high potential of biogenic hydroxyapatite bioceramics modified by graphene-like structures using CVD method for medical application.

Accelerated reconstruction of rat calvaria bone defect using 3D-printed scaffolds coated with hydroxyapatite/bioglass

Self-healing and autologous bone graft of calvaraial defects can be challenging. Therefore, the fabrication of scaffolds for its rapid and effective repair is a promising field of research. This paper provided a comparative study on the ability of Three-dimensional (3D) printed polycaprolactone (PCL) scaffolds and PCL-modified with the hydroxyapatite (HA) and bioglasses (BG) bioceramics scaffolds in newly bone formed in calvaria defect area. The studied 3D-printed PCL scaffolds were fabricated by fused deposition layer-by-layer modeling. After the evaluation of cell adhesion on the surface of the scaffolds, they were implanted into a rat calvarial defect model. The rats were divided into four groups with scaffold graft including PCL, PCL/HA, PCL/BG, and PCL/HA/BG and a non-explant control group. The capacity of the 3D-printed scaffolds in calvarial bone regeneration was investigated using micro computed tomography scan, histological and immunohistochemistry analyses. Lastly, the expression levels of several bone related genes as well as the expression of miR-20a and miR-17-5p as positive regulators and miR-125a as a negative regulator in osteogenesis pathways were also investigated. The results of this comparative study have showed that PCL scaffolds with HA and BG bioceramics have a great range of potential applications in the field of calvaria defect treatment.

The combined effects of binder addition and different sintering methods on the mechanical properties of bovine hydroxyapatite

Hydroxyapatite (HA) from bovine bones has been used as a biomaterial in dentistry due to its biocompatibility and bioactivity. However, dense HA bioceramics still present inadequate properties for applications that require high mechanical performance, such as infrastructure. Microstructural reinforcements and control of ceramic processing steps are methods to improve these shortcomings. The present study assessed the effects of polyvinyl butyral (PVB) addition in combination with two sintering methodologies (2-step and conventional), on the mechanical properties of polycrystalline bovine HA bioceramics. The samples were divided into four groups (with 15 samples per group): conventional sintering with binder (HBC) and without binder (HWC) and 2-step sintering with (HB2) and without binder (HW2). HA was extracted from bovine bones, turned into nanoparticles in a ball mill, and subjected to uniaxial and isostatic pressing into discs, according to ISO 6872 standards. All groups were characterized by x-ray diffractometry (XRD), differential thermal analysis (DTA) and Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and relative density. Besides, mechanical analyses (biaxial flexural strength (BFS) and modulus of elasticity) were also performed. The characterization results demonstrated that adding agglutinants or the sintering method did not affect HA's chemical and structural characteristics. Even so, the HWC group showed the highest mechanical values for BFS and modulus of elasticity being 109.0 (98.0; 117.0) MPa and 105.17 ± 14.65 GPa, respectively. The HA ceramics submitted to conventional sintering and without the addition of binders achieved better mechanical properties than the other groups. The impacts of each variable were discussed and correlated to the final microstructures and mechanical properties.

Characteristics of Bioceramic Hydroxyapatite Based on Sand Lobster Shells (<i>Panulirus homarus</i>) as Sources of Calcium with Optimal Calcination Temperature

In this work, bioceramic hydroxyapatite (HAp) was synthesized based on sand lobster shells (Panulirs homarus) as a source of calcium using the precipitation method. Sand lobster shell powder was calcinated with temperature variations of 600, 800, and 1000 °C for 6 hours. The effect of calcination temperature on sand lobster shell powder was characterized to determine the optimal temperature for the synthesis of HAp. Based on the XRF (X-Ray Fluorescence) characterization, the highest calcium content (Ca) was 93% at a calcination temperature of 1000 oC. This result was supported by FTIR (Fourier Transform Infrared) spectrum that increasing the calcination temperature will reduce the intensity of carbonate ion (CO32-). These results showed that 1000 °C was the best calcination temperature on sand lobster shells to synthesize HAp. The characterization result of HAp using EDX (Energy Dispersive X-Ray) revealed that the molar ratio of Ca/P was 1.73. The FTIR and XRD (X-Ray Diffractometer) spectral pattern indicate that HAp had been successfully synthesized with minor-TCP, which is also a calcium phosphate with high biocompatibility.

Single Immediate Implant Placement into Anterior Maxillary Sockets with Facial Bone Defects: A 5-Year Retrospective Study

Purpose: To evaluate the long-term functional and esthetic effects of immediate implantation combined with guided bone regeneration in patients with labial bone plate defects. Materials and Methods: A total of 46 implants were immediately placed into anterior maxillary fresh sockets with buccal bone defects. Jumping space and the outer side of buccal defects were densely filled with hydroxyapatite bioceramics and covered with biomembrane. CBCT was performed immediately after surgery (T1), 6 months later (T2), and after 5 years (T3). Radiographs were taken at 1 month after surgery (RT1), definitive crown delivery (RT2), and once a year after prosthetic loading (RT3 to RT7) for 5 years. Pink esthetic score (PES) was evaluated at the time of definitive crown delivery (PT1) and at follow-up visits 1, 3, and 5 years (PT2 to PT4) after crown fixation. Results: No implants were lost during the observational period. The labial bone was radiographically reconstructed to acceptable volumes, with an average 2.86-mm horizontal bone and 2.2-mm vertical bone. Significant marginal bone loss occurred within 1 year after delivery of the definitive prosthesis. PES scores did not reveal inferior results at the 5-year follow-up. Conclusion: When other conditions are met for immediate implant placement, small labial plate defects (≤ 5 mm) will not affect the long-term esthetic effect.

Synthesis Techniques of Bioceramic Hydroxyapatite for Biomedical Applications

The need to develop surviving implants and bone substitutes with good biocompatibility, mechanical strength and bioactivity, without causing toxicity, immune rejection and cancer had attracted the attention of many researchers over the years. Hydroxyapatite (HA) is one of the excellent calcium phosphates and major mineral component of vertebrate bone and teeth, which considerably enhances the biocompatibility, mechanical strength and bioactivity of artificial biomaterials in the body system. In addition, it creates porous and rough coated surface that aids the cell attachment, proliferation and the growth of tissue on the bone implants. Due to its high demand in biomedical applications, scientists had developed several, simple and efficient techniques to produce HA. This review outlines several techniques of manufacturing HA and summarizes the merits and demerits of each technique. Keywords: Biomaterials, calcium phosphate, hydroxyapatite, preparation techniques and bone

New Approach to Identify the Physiological State of Bone Cells at the Surface of Hydroxyapatite Bioceramics

The aim of this work was to identify robust and reproducible signatures characterizing the different steps of bone cell differentiation, from precursors to mature bone cells, using approaches allowing characterization by label-free imaging. Human mesenchymal stromal cells (hMSCs) were cultured either in a growth medium (GM), unable to induce cell differentiation by itself, or in an osteogenic differentiation medium (ODM) on hydroxyapatite ceramics or borosilicate glass. Cell density as well as cell structure, size, and morphology were investigated. A fluorescence microscopy-based approach was followed, using fluorescent labelling of cell features. Some early morphological changes of hMSC during osteogenic differentiation were identified as soon as 48h that were accentuated after 7 days of culture. Cell density was higher when cells were cultured in GM and the cells exhibited significantly smaller nuclei (size ratio about 1.3-1.5) than those cultured in ODM, regardless of the culture support. In ODM, the cells were also of bigger size (1.2 to 1.5 times) and their focal adhesions were reinforcedType I collagen, a gold standard marker of osteogenic differentiation, appeared more intense in ODM. These cell features can be determined using multimodal label-free imaging methods to characterize the differentiation state of hMSCs at the biomaterial surface. They give rise to new cost-effective approaches to investigate cell behavior by suppressing the chemical markers and reducing both the number of needed samples and the requested time to do so.

Investigation of Microwave Sintering of B-Type Carbonated Hydroxyapatite Bioceramics

B-type carbonated hydroxyapatite (CBHA) is potentially an excellent biodegradable bioceramic for bone repair. However, conventional sintering results in formation of undesired phases. Therefore, microwave sintering of CBHA was investigated to assess the possibility to reduce formation of unwanted phases. Pellets with 0.8 mol% of B-type carbonate were sintered in a multimode instrumented cavity under static air with short thermal cycles. They were prepared from a CBHA powder alone and from a mixture of CBHA and carbon powder to generate a local in-situ CO2 atmosphere. XRD, FT-IR, SEM and BET analyses indicated that CBHA densification with increase temperature lead to decomposition into apatite. The addition of carbon powder to the CBHA that generate a CO2-rich atmosphere around the samples did not prevent the decomposition. Efficient control of temperature and atmosphere composition is required to improve microwave sintering of CBHA bioceramics.

TiO2 nanoparticles added to dense bovine hydroxyapatite bioceramics increase human osteoblast mineralization activity

ObjectivesThis study evaluated the effect of TiO2 nanoparticles + dense hydroxyapatite (HA) on human osteoblast cells (SAOS-2). MethodsParticulate bovine HA powder with or without the addition of either 5 or 8 % TiO2 (HA, HA/TiO2Np5 % or HA/TiO2Np8 %) were pressed into disks (Ø = 12.5 mm; thickness = 1.3 mm) uniaxially (100 MPa) and isostatically (200 MPa/1 min) and sintered at 1300 °C. Y-TZP disks were used as control. The following tests were performed: Scanning Electron Microscopy and Dispersive Energy Spectroscopy (SEM/EDS), Atomic Force Microscopy (AFM), cell viability assay (Alamar Blue-AB) and mineralized matrix deposition (Alizarin Red-AR). AB and AR data were submitted to 2-way ANOVA/Tukey tests and ANOVA/Tukey tests, respectively. ResultsSEM revealed that the surface of HA/TiO2Np5% resembles DPBHA surface, but also contains smaller granules. HA/TiO2Np8% characteristics resembles HA/TiO2Np5% surface, but with irregular topography. Y-TZP showed a typical oxide ceramic surface pattern. EDS revealed Ca, O, and P in all samples. C, O, and Zr appeared in Y-TZP samples. AFM data corroborates SEM analysis. AB test revealed excellent cellular viability for HA/TiO2Np5% group. AR test showed that all groups containing TiO2np had more mineralized matrix deposition than all other groups, with statistically differences between HA/TiO2Np8% and HA cultivated in non-osteogenic medium. Culture in osteogenic medium exhibited much more mineralized matrix deposition by TiO2np groups. SignificanceIn conclusion, the addition of TiO2np showed chemical, superficial, and biological changes in the reinforced materials. HA/TiO2Np5% showed the best results for cell viability and HA/TiO2Np8% for mineralized matrix deposition.