Commercial Hydroxyapatite Research Articles

Characteristics of hydroxyapatite from buffalo bone waste synthesized by precipitation method

Hydroxyapatite (HA), Ca10(PO4)6(OH)2, is the most widely used ceramic biomaterials. It is a mineral found in natural teeth, bone and hard tissue. In this paper, we present a synthesis and characterization for obtaining HA by wet precipitation. This study mainly focuses on the use of bio-waste materials, i.e., buffalo bones to obtain HA. In order to synthesized HA from buffalo bones, we use Ca(OH)2, H20 and H3PO4 as the starting precursors. The material was sintered at temperatures of 650 °C, 850 °C, and 1050 °C for 7 hours to improve its particle size distribution. Identification of functional group using FTIR shows absoption namely at wavenumber values of 3699.20, 3787.92 and 3706.91 cm−1 which indicate hydroxyl group (OH). Phosphate band were identified by peak 1022.20 and 1118.63 cm−1 and 1215.06 to 1459.31−1cm which indicates carbonate group. Ratio of Ca/P for synthesized HA is about 1.67. XRD pattern results indicated that the synthesized buffalo bone HA closely correspond to commercial HA phase.

Effect of aqueous concentration of humic acid on the sorption of polychlorinated biphenyls onto soil particle grain sizes

The role of initial aqueous humic acid concentrations (dose), as well as secondary environmental conditions on the sorption of PCB congeners PCB 28, 52, 77, 101, 105, 138, 153, and 180 onto soil particle grain sizes, was investigated in this study. Scanning electron microscopy equipped with energy dispersive X-ray and Fourier transform infrared spectroscopy were used for the internal morphology and qualitative elemental analysis, as well as identification of possible functional groups found in commercial HA. Batch adsorption experiments were used for sorption studies. The results showed that the sorption of PCBs onto soil decreased with an increase in the aqueous HA concentrations. The adsorption of the selected PCBs onto the soils was found to decrease with an increase in the solution pH of humic acid. Thermodynamic studies showed that the partition coefficient values increased with an increase in solution temperature. All the standard free energy were negative indicating the spontaneity and feasibility of the sorption process with positive and high enthalpy and entropy values of the system. The sorption was best fitted with the Freundlich isotherm with the intensity parameter 1/n found to be greater than 1. The outcome of this study revealed that secondary pollution of river water may possibly be altered depending on variations in the environmental conditions such as pH and temperature. The presence of organic pollutants in alkaline soils having less organic matter content could increase the chances of leaching of organic pollutants causing groundwater contamination.

Influence of Bicationic and Catanionic Surfactants Over the Morphology of Mesoporous Nanohydroxyapatite.

In the co-precipitation method, the morphology of nano Hydroxyapatite (HAp) is usually being controlled by parameters like pH, temperature, concentration, and the ratio of the mixed surfactants. In the present work, effective tailoring of morphology has been done by exploiting the electrostatic interaction between surfactants by grouping them as catanionic (Cetrimide and SDS) and bicationic (Cetrimide and CTAB), with weight ratio of 1:1 and total concentration of 0.28 g/100 ml. The prepared samples were subjected to various characterizations like FTIR, XRD, FESEM, HRTEM, TGA/DTA, and BET analysis. The results show that the samples are in HAp phase, nano size and mesoporous in nature. The FESEM images reveal the fact that the catanionic surfactant enhances the growth of particle from sphere to hexagonal rod whereas bicationic mixture suppresses the growth and results in a disk-like HAp. The samples were subjected to AAS test for finding the Ca2+ ion release rate in SBF and were compared with a commercial nanocrystalline HAp sample. The Ca2+ ion release test of the samples shows signs of better bioactivity of disk-like HAp than that of commercial one.

The Influence of Scaffold Designs on Cell Seeding Efficiency in Establishing A Three-Dimensional Culture

The concept of Bone Tissue Engineering (BTE) based on cell-seeded scaffold holds great promise for the treatment of bone defects. However, much optimization is required in establishing a three-dimensional (3D) culture before BTE can be successfully applied clinically. In this study, we have assessed the influence of scaffold designs on the initial cell seeding efficiency of anchorage cells. The rapid prototyping designed polylactic acid (PLA) scaffolds fabricated using fused deposition modelling (FDM) designated by 2C and 4C scaffolds were compared to the commercial hydroxyapatite (HA) scaffold. Prior to cell seeding, 2C and 4C scaffolds were deposited with silicon carbonated HA nanopowders / Hyaluronic acid / Collagen Type I by Polyelectrolyte Multilayers (PEMs) coating and sterilized under ultra-violet (UV) radiation. Human Bone Marrow derived-Mesenchymal Stem Cells (hMSCs) were then cultured on the scaffolds using different volume of cell suspension, seeding method (one-side and two-sides; coated and non-coated well plates) and culture condition (static and rotary bioreactor). Regardless of scaffold designs, cell-seeded scaffold with small volume of cell suspension and two-sides seeding using coated well plate resulted in better cell attachment and distribution across the surface of the scaffolds than one-sided seeding. In any case, commercial HA exhibited lower percentages of cell attachment. Culturing these scaffolds in different media but culturing these scaffolds in rotary bioreactor has pronounced impact on the cell survival as compared to static condition.

Osteoblast Cell Response to Naturally Derived Calcium Phosphate-Based Materials.

The demand of calcium phosphate bioceramics for biomedical applications is constantly increasing. Efficient and cost-effective production can be achieved using naturally derived materials. In this work, calcium phosphate powders, obtained from dolomitic marble and Mytilus galloprovincialis seashells by a previously reported and improved Rathje method were used to fabricate microporous pellets through cold isostatic pressing followed by sintering at 1200 °C. The interaction of the developed materials with MC3T3-E1 pre-osteoblasts was explored in terms of cell adhesion, morphology, viability, proliferation, and differentiation to evaluate their potential for bone regeneration. Results showed appropriate cell adhesion and high viability without distinguishable differences in the morphological features. Likewise, the pre-osteoblast proliferation overtime on both naturally derived calcium phosphate materials showed a statistically significant increase comparable to that of commercial hydroxyapatite, used as reference material. Furthermore, evaluation of the intracellular alkaline phosphatase activity and collagen synthesis and deposition, used as markers of the osteogenic ability of these bioceramics, revealed that all samples promoted pre-osteoblast differentiation. However, a seashell-derived ceramic demonstrated a higher efficacy in inducing cell differentiation, almost equivalent to that of the commercial hydroxyapatite. Therefore, data obtained demonstrate that this naturally sourced calcium-phosphate material holds promise for applications in bone tissue regeneration.

Comparative Study of Bioceramic Powders Synthesis Based on Calcium and Phosphates

Abstract In this paper is presented a comparative study regarding the synthesis of hydroxyapatite powders. The chosen method of synthesis of this biomaterial was chemical co-precipitation. The structure, size and morphology of the obtained powders were analyzed by X-ray diffraction, infrared spectroscopy - FTIR, dynamic light diffusion DLS tehnique and scanning electron microscopy-SEM. The results obtained were compared with those obtained on a commercial hydroxyapatite powder. Investigation methods have confirmed the synthesis of a high purity hydroxyapatite with a optimal degree of crystallization and crystallinity for the reconstruction and regeneration of hard tissue.

Vascular biosafety of commercial hydroxyapatite particles: discrepancy between blood compatibility assays and endothelial cell behavior

BackgroundVascular homeostasis is ensured by a dynamic interplay involving the endothelium, the platelets and the coagulation system. Thus, the vascular safety of particulate materials must address this integrated system, an approach that has been largely neglected. This work analysed the effects of commercial hydroxyapatite (HA) particles in blood compatibility and in endothelial cell behavior, due to their clinical relevance and scarcity of data on their vascular biosafety.ResultsParticles with similar chemical composition and distinct size and morphology were tested, i.e. rod-like, nano dimensions and low aspect ratio (HAp1) and needle-shape with wider size and aspect ratio (HAp2). HAp1 and HAp2, at 1 to 10 mg/mL, did not affect haemolysis, platelet adhesion, aggregation and activation, or the coagulation system (intrinsic and extrinsic pathways), although HAp2 exhibited a slight thrombogenic potential at 10 mg/mL. Notwithstanding, significantly lower levels presented dose-dependent toxicity on endothelial cells’ behavior. HAp1 and HAp2 decreased cell viability at levels ≥ 250 and ≥ 50 μg/mL, respectively. At 10 and 50 μg/mL, HAp1 did not interfere with the F-actin cytoskeleton, apoptotic index, cell cycle progression, expression of vWF, VECad and CD31, and the ability to form a network of tubular-like structures. Comparatively, HAp2 caused dose-dependent toxic effects in these parameters in the same concentration range.ConclusionThe most relevant observation is the great discrepancy of HA particles’ levels that interfere with the routine blood compatibility assays and the endothelial cell behavior. Further, this difference was also found to be dependent on the particles’ size, morphology and aspect ratio, emphasizing the need of a complementary biological characterization, taking into consideration the endothelial cells’ functionality, to establish the vascular safety of particulate HA.

Adsorption and desorption of uranium(VI) onto humic acids derived from uranium-enriched lignites.

Humic acids (HAs) were extracted and characterized from three kinds of uranium-enriched lignites from Yunnan province, China. Batch experiments were used to study the adsorption and desorption behavior of uranium (VI) onto these HAs and a commercial HA. The results showed that the optimum pH level at which all the HAs adsorbed uranium(VI) ranged from 5 to 8. The high uranium content of the HAs was released into the solution at the pH values between 1 and 3; when the HA dosage was 2.5 g L-1, the maximum concentration of uranium was 44.14 μg L-1. This shows that HAs derived from uranium-enriched lignites may present a potential environmental risk when used in acidic conditions. The experimental data were found to comply with the pseudo-second-order kinetic model, and the adsorption isotherms fit the Langmuir and Freundlich models well. The desorption experiments revealed that the sorption mechanism was controlled by the complex interactions between the organic ligands of the HAs and uranium(VI). The uranium present in the HAs may not affect the adsorption capacity of the uranium(VI), but the carboxylic and phenolic hydroxyl groups in the HAs play a significant role in controlling the adsorption capacity.

Effect of Reaction Time on Phosphate Mineralization from Microalgae Hydrolysate

The development of algal biorefineries is strongly associated with the nutrient management, particularly phosphorus, which is a limited mineral resource. Flash hydrolysis (FH) has been widely applied to a variety of algae species to fractionate its constituents. This chemical-free, subcritical water technique was used to extract more than 80 wt % of phosphorus available in the Scenedesmus sp. as water-soluble phosphates in the aqueous phase (hydrolysate). The phosphate-rich hydrolysate was subjected to the hydrothermal mineralization (HTM) process at 280 °C and 5–90 min of residence time to mineralize phosphates as allotropes of calcium phosphate such as hydroxyapatite (HAp) and whitlockite (WH). In the current study, the effect of reaction time on phosphate mineralization from the hydrolysate as well as the composition, structure and the morphology of the precipitates were studied. Calcium hydroxide and commercial HAp were used as the mineralizer and seeding material, respectively. More than 97 wt % of p...

Physical, mechanical, and biological properties of electrophoretically deposited lithium-doped calcium phosphates

In the present work, the preparation of sintered lithium-doped tricalcium phosphates was studied, along with their physical, mechanical, and biological properties. Calcium phosphates were shaped via the use of electrophoretic deposition (EPD), using colloidally milled dispersions of hydroxyapatite (HAp) particles. The dispersions were stabilised with monochloroacetic acid. Lithium was incorporated into the structure via an addition of lithium chloride, which also served to optimise the deposition process. The dispersions were milled colloidally for periods of 0–48h. The colloidal milling resulted in two effects: i) disintegration of the commercial HAp powder (10µm) agglomerates, ii) unimodal distribution of the HAp particles (~ 170nm). The fine particles of the milled HAp dispersions accelerated the deposition rate, and increased the mass of the deposit. The reduced size of the initial particles, owed to the milling, led to the superior arrangement of the particles during deposition and to reduced porosity after sintering (1050–1250°C). The HAp decomposed into tricalcium phosphate phases during sintering. At a sintering temperature of 1250°C, grain growth occurred, which consequently resulted in a slight degradation of the mechanical properties (reduction in hardness and Young's modulus). In contrast, the hardness and Young's modulus increased as the dispersion milling time increased (smaller grain size after sintering); however, the fracture toughness did not change. The results of the biological testing confirmed the bioactivity of the material through the growth of the apatite layer in the simulated body fluid (SBF), and the biodegradation of the prepared materials in the Tris-HCl solution. With regard to the preparation of compact lithium-doped tricalcium phosphates, the best results were obtained in the case of the sample that utilised the dispersion that was milled for 48h, and was sintered at 1050°C.

Guar gum: A novel binder for ceramic extrusion

Ceramic honeycomb extrusion is a technique capable of attaining high strength, porous ceramics. However, challenges prevent the realisation of its potential. These include the design of an intricate honeycomb die and the formulation of an extrudable paste. The present study addresses the latter by using guar gum (GG) as a binder. GG was rationally selected because hydrogels thereof exhibit strong shear-thinning and high stiffness properties, which are required for extrusion. Rheological analyses demonstrated ceramic pastes with similar qualities were achieved, with hydroxyapatite (HA) used as the model ceramic. The shear stiffness modulus of HA pastes was determined as 8.4MPa with a yield stress of 1.1kPa. Moreover, this was achieved with GG as the sole additive, which further facilitates the overall fabrication process. The binder extraction notably occurred at relatively low temperatures when other high molecular weight polymers demand temperatures above 1000°C; therefore the latter precludes the use of ceramics with low sintering onset. The process culminated in a porous HA scaffold with similar porosity to that of a commercial HA graft, but with higher compressive strength. Lastly, the study notes that the biological and water-soluble properties of GG can broaden its application into other ceramic fabrication processes.

Bioactivity and mineralization of natural hydroxyapatite from cuttlefish bone and Bioglass® co-sintered bioceramics.

In this study, bioactive hydroxyapatite (HAP)-based bioceramics starting from cuttlefish bone powders have been prepared and characterized. In particular, fragmented cuttlefish bone was co-sintered with 30 wt% of Bioglass® -45S5 to synthesize HAP-based powders with enhanced mechanical properties and bioactivity. Commercial synthetic HAP was treated following the same procedure and used as a reference. The structure and composition of the bioceramics formulations were characterized using Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. After the thermal treatment of cuttlefish bone powder added with 30 wt% Bioglass, new phases with compositions of sodium calcium phosphate [Na3 Ca6 (PO4 )5 ], β-tricalcium phosphate [Ca3 (PO4 )] and amorphous silica were detected. In vitro cell culture studies were performed by evaluating proliferation, metabolic activity and differentiation of human osteoblast-like cells (MG63). Scaffolds made with cuttlefish bone powder exhibited increased apatite deposition, alkaline phosphatase activity and cell proliferation compared with commercial synthetic HAP. In addition, the ceramic compositions obtained after the combination with Bioglass® further enhanced the metabolic activity of MG63 cell and promoted the formation of a well-developed apatite layer after 7 days of incubation in Dulbecco's modified Eagle's medium.

Antimicrobial modified hydroxyapatite composite dental bite by stereolithography

This study is aimed at the synthesis of antimicrobial hydroxyapatite (HAP)‐based composites for dental application by stereolithography (SLA). A micron‐sized commercial HAP was modified by methacrylate and quaternary ammonium salt, and, then, it was used in different amounts (namely 2.5, 5, and 10 wt%) as filler for a photocurable custom made resin for SLA. Thermal stability, microstructure, and particles size of the pristine (HAP) and modified HAP (mHAP) were evaluated by thermogravimetric analysis (TGA), X‐ray diffraction (XRD), and particle size analyser (CILAS). The suitability of each formulation for stereolithography process was assessed by measuring viscosity, degree of conversion (DC%) by Fourier transform infrared spectroscopy (FTIR), glass transition temperature, and thermal stability. Photo‐cured specimens for physical, mechanical, and antimicrobial testing were built by SLA. The flexural strength of the samples was measured using a 3‐point bending test method, and the fractured surface was analysed by scanning electron microscopy (SEM). The antimicrobial activity of samples was investigated against some standard microorganisms (Staphylococcus aureus, Escherichia coli, and Candida albicans), as representative Gram positive and Gram negative bacteria and fungus, respectively. The flexural strength increased with a filler content up to 5% and slightly decreased for higher content. SEM analysis confirmed the presence of uniformly distributed HAP. The incorporation of mHAP reduced the bacterial and fungal growth in dose‐dependent manner in comparison with the neat samples. Finally, a prototype of dental bite was built by SLA.

Study of the suitability of a commercial hydroxyapatite powder to obtain sintered compacts for medical applications

Hydroxyapatite (HA) is a material widely used by the medical community due to its Ca/P ratio is comparable to the Ca/P ratio of bones and teeth, which promotes osteoinduction and osteoconduction processes when in contact with bone tissue, either as volume piece or coating. This work focuses on studying the quality of the commercial HA powder MKnano-#MKN-HXAP-S12 µm, after processing, to obtain sintered compact discs with suitable physical and chemical characteristics for implants applications. The HA powder was processed through calcination, grinding, pressing and sintering to evaluate the effect of such as procedures in the compacts dics quality. The raw powder was characterized by laser diffraction, SEM, XRF, XRD, TGA and DSC while the characteristics of the obtained compact discs were determined by dilatometry and XRD to identify the sintering temperature range, constituent phases, the amorphous content and the crystallinity degree, parameters that allow determining their suitability for implants applications. Although, it was not possible to obtain sintered compacts with the suitable chemical composition and without fractures, this work allowed to identify the parameters that determine the suitability of a HA powder to obtain sintered compacts for medical applications, as well as the characterization protocol that allows the evaluation of such parameters.

Adhesion profile and differentiation capacity of human adipose tissue derived mesenchymal stem cells grown on metal ion (Zn, Ag and Cu) doped hydroxyapatite nano-coated surfaces

Accelerated Mesenchymal Stem Cells (MSCs) condensation and robust MSC-matrix and MSC-MSC interactions on nano-surfaces may provide critical factors contributing to such events, likely through the orchestrated signal cascades and cellular events modulated by the extracellular matrix. In this study, human adipose tissue derived mesenchymal stem cells (hMSC)', were grown on metal ion (Zn, Ag and Cu) doped hydroxyapatite (HAP) nano-coated surfaces. These metal ions are known to have different chemical and surface properties; therefore we investigated their respective contributions to cell viability, cellular behavior, osteogenic differentiation capacity and substrate-cell interaction. Nano-powders were produced using a wet chemical process. Air spray deposition was used to accumulate the metal ion doped HAP films on a glass substrate. Cell viability was determined by MTT, LDH and DNA quantitation methods Osteogenic differentiation capacity of hMSCs was analyzed with Alizarin Red Staining and Alkaline Phosphatase Specific Activity. Adhesion of the hMSCs and the effect of cell adhesion on biomaterial biocompatibility were explored through cell adhesion assay, immunofluorescence staining for vinculin and f-actin cytoskeleton components, SEM and microarray including 84 known extracellular matrix proteins and cell adhesion pathway genes, since, adhesion is the first step for good biocompability. The results demonstrate that the viability and osteogenic differentiation of the hMSCs (in growth media without osteogenic stimulation) and cell adhesion capability are higher on nanocoated surfaces that include Zn, Ag and/or Cu metal ions than commercial HAP. These results reveal that Zn, Ag and Cu metal ions contribute to the biocompatibility of exogenous material.

Eu3+ Sequestration by Biogenic Nano-Hydroxyapatite Synthesized at Neutral and Alkaline pH

ABSTRACTBiogenic hydroxyapatite (bio-HA) has the potential for radionuclide capture and remediation of metal-contaminated environments. Biosynthesis of bio-HA was achieved via the phosphatase activity of a Serratia sp. supplemented with various concentrations of CaCl2 and glycerol 2-phosphate (G2P) provided at pH 7.0 or 8.6. Presence of hydroxyapatite (HA) was confirmed in the samples by X-ray powder diffraction analysis. When provided with limiting (1 mM) G2P and excess (5 mM) Ca2+ at pH 8.6, monohydrocalcite was found. This, and bio-HA with less (1 mM) Ca2+ accumulated Eu(III) to ∼31% and 20% of the biomineral mass, respectively, as compared to 50% of the mineral mass accumulated by commercial HA. Optimally, with bio-HA made at initial pH 7.0 from 2 mM Ca2+ and 5 mM G2P, Eu(III) accumulated to ∼74% of the weight of bio-HA, which was equal to the mass of the HA mineral component of the biomaterial. The implications with respect to potential bio-HA-barrier development in situ or as a remediation strategy are discussed.

EXTRACTION, CHARACTERIZATION AND ANTIMICROBIAL ACTIVITY OF HYDROXYAPATITE FROM SEABASS AND SEABREAM SCALE

The present study investigates the characterization of hydroxyapatite (HAp) extracted from seabass and seabream scales as by-product. Fish scales obtained from a seafood processing company were used to extract natural HAp powder. HAp powder was extracted by alkaline heat treatment of fish scales and the synthesized HAp (FS-HAp) was extensively characterized with Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Calcium to phosphate ratio of the HAp was confirmed by inductively coupled plasma (ICP) and elemental analysis of HAp were also carried out using energy dispersive x-ray spectroscopy (EDS). The results of the characterization analysis were compared with commercial hydroxyapatite standard (CHAp) and it was clearly confirmed that the extracted FS-HAp exactly showed CHAp characteristics physicochemically which is used as biomaterial. However, well diffusion assay revealed out that synthesized hydroxyapatite showed no activity against C. albicans , S. aureus and E. coli . It was concluded that, instead of synthetic apatite, extracted FS-HAp presents a potential promising biomaterial as the raw materials are by-product which economically cheap and sustainable substances.

Effect of hydroxyapatite surface morphology on cell adhesion

We obtained hydroxyapatite (HAp) materials as a block by mixing HAp nanoparticles and polymer, and then calcining the mixtures. The surface morphology of the HAp materials was tuned by varying heat treatment conditions. After calcining the mixtures at 1200 or 800°C for 4h, the surface morphology of the HAp materials was flat or convexo-concave, respectively. The flat surface morphology, which showed micrometer-ordered grain boundaries, was formed by the aggregation of HAp nanoparticles. On the other hand, the convexo-concave surface morphology resulted from the agglomeration of HAp nanoparticles after heat treatment at 800°C for 4h with nanometer-ordered particle size. We tested cell adhesion to HAp materials with flat or convexo-concave surface morphology and found that cells adhered well to the flat HAp materials but not to the convexo-concave HAp materials. This technique for selectively preparing HAp materials with flat or convexo-concave surface morphology was very easy because we merely mixed commercial HAp nanoparticles with polymer and then calcined the mixtures. As a result, the heat treatment temperature affected the surface morphology of our HAp materials, and their surface morphologies contributed to cell adhesion independently of other material properties.

Continuous-flow precipitation as a route to prepare highly controlled nanohydroxyapatite: in vitro mineralization and biological evaluation

This work reports the biological evaluation of nanosized hydroxyapatite (HAp) previously synthesized by continuous-flow precipitation in a scaled-up meso oscillatory flow reactor (meso-OFR). Physico-chemical characterization of the synthesized HAp suggests high surface reactivity namely because of its high specific surface area and low crystallinity. On the other hand, in vitro biomineralization assays demonstrated the apatite-forming activity of the prepared HAp and their higher surface reactivity when compared to a commercial HAp. Furthermore, human osteoblastic-like (Saos-2) cells culture evidenced that the synthesized HAp stimulated cell proliferation, especially when applied at lower concentrations (30 and 50 μg ml−1), although its cellular uptake behavior. Therefore, the prepared HAp shows immense potential as biomedical material, as well as drug and gene delivery vehicle. The results are also very promising regarding further scaling up of the process, as the designed methodology allow for the preparation in a continuous mode of nanosized HAp with controlled physico-chemical properties.

바이러스 안전성이 보증된 돼지유래 골 이식재 제조 공정 개발

A process for manufacturing virally-safe porcine bone hydroxyapatite (HA) has been developed to serve as advanced xenograft material for dental applications. Porcine bone pieces were defatted with successive treatments of 30% hydrogen peroxide and 80% ethyl alcohol. The defatted porcine bone pieces were heat-treated in an oxygen atmosphere box furnace at 1,300°C to remove collagen and organic compounds. The bone pieces were ground with a grinder and then the bone powder was sterilized by gamma irradiation. Morphological characteristics such as SEM (Scanning Electron Microscopy) and TEM (Transmission Electron Microscopy) images of the resulting porcine bone HA (THE Graft ® ) were similar to those of a commercial bovine bone HA (Bio-Oss ® ). In order to evaluate the efficacy of 1,300°C heat treatment and gamma irradiation at a dose of 25 kGy for the inactivation of porcine viruses during the manufacture of porcine bone HA, a variety of experimental porcine viruses including transmissible gastroenteritis virus (TGEV), pseudorabies virus (PRV), porcine rotavirus (PRoV), and porcine parvovirus (PPV) were chosen. TGEV, PRV, PRoV, and PPV were completely inactivated to undetectable levels during the 1,300oC heat treatment. The mean log reduction factors achieved were ≧4.65 for TGEV, ≧5.81 for PRV, ≧6.28 for PRoV, and ≧5.21 for PPV. Gamma irradiation was also very effective at inactivating the viruses. TGEV, PRV, PRoV, and PPV were completely inactivated to undetectable levels during the gamma irradiation. The mean log reduction factors achieved were ≧4.65 for TGEV, ≧5.87 for PRV, ≧6.05 for PRoV, and ≧4.89 for PPV. The cumulative log reduction factors achieved using the two different virus inactivation processes were ≧9.30 for TGEV, ≧11.68 for PRV, ≧12.33 for PRoV, and ≧10.10 for PPV. These results indicate that the manufacturing process for porcine bone HA from porcine-bone material has sufficient virus-reducing capacity to achieve a high margin of virus safety.