Are Veterinary Costs and Socioeconomic Status Risk Factors for Companion Animal Relinquishment in the Republic of Korea?

More than 110,000 companion animals are sent to shelters each year due to abandonment in Republic of Korea, and there is a need to analyze the causes of the relinquishment of animals and implement appropriate policies. Veterinary costs have been blamed for this issue in Republic of Korea above the reported leading causes of socioeconomic status of owners, cost and behavior issues of the animals, or housing restrictions. However, it is rare to find supporting evidence. In this study, we aimed to determine whether veterinary costs and socioeconomic factors are related to animal relinquishment in Republic of Korea. Multiple regression models were used to test if veterinary costs and socioeconomic indicators can account for relinquishment in 128 regions of Republic of Korea in 2020 and 2021. When five independent variables (two veterinary cost data and three socioeconomic indicators) were included, the regression model showed significance in explaining pet relinquishment in 2020, with an adjusted coefficient of determination of 0.3956. Pet relinquishment can also be explained by the same five variables for 2021, with an adjusted coefficient of determination of 0.391 with p < 0.0001. The findings suggest that intervention to reduce companion animal relinquishment in Republic of Korea should focus on lightening the financial burdens of owners as the socioeconomic status of a community worsens.

Evaluation of Biomechanical Properties and Morphometric Structures of the Trachea in Pigs and Rabbits.

BACKGROUND/AIM: Animals differ in the biochemical composition, attachments, and mechanical properties of tracheal cartilage. This study examined the biomechanical properties and morphological structure of the trachea of pigs, and rabbits as preclinical models. MATERIALS AND METHODS: The trachea in pigs and rabbits can be divided into four regions, cranial cervical, middle cervical, thoracic inlet, and intra-thoracic parts. RESULTS: The total number of tracheal rings in pigs and rabbits was 32-35 and 34-38 rings, respectively. The pig bronchus first branches from the trachea, reaching the cranial lobe of the lungs before branching to the main bronchus, while the rabbit bronchus branched after the main bronchus. A comparison of the posterior region of the crosssectional trachea shows that the rabbit has a C-shape with cartilage connected to the tracheal muscle, and the pig has the tracheal muscle covered with cartilage. The trachea of pigs and rabbits decreased in tracheal thickness and size from the thoracic inlet toward the lungs. The stress-strain in the longitudinal and transverse tensile test was higher in rabbits than in pigs. The tensile stress of the four regions was significantly different in the transverse tensile test (p<0.001). In the bending test, more force was required to bend pig than rabbit tracheas. Microscopic and scanning electron microscopy showed no structural differences in tracheal cartilage between the two species. CONCLUSION: These results suggest that there is great variation in morphology and physical properties of the trachea in pigs and rabbits. We found porcine tracheas have similar biomechanical properties to those of humans.

Anti-obesity Effects of Dark Tea Extracts by Down-regulation of C/EBPα and PPARγ.

BACKGROUND/AIM: Dark tea, made by fermentation of tea leaves using microorganisms, is well known for its antiobesity effect; however, studies to identify this effect have not been sufficiently conducted. Herein, the anti-obesity effects of post-fermented dark tea were studied in high-fat diet mouse. MATERIALS AND METHODS: Obesity was induced through a high-fat diet in C57BL/6 mice, and then dark tea extract powder (DTP) was orally administered daily for 12 weeks to evaluate the body and organ weights. Changes in the biochemical markers of obesity were evaluated to study the mechanism of the anti-obesity effects of DTP. RESULTS: When DTP was administered to obesity mice, the weight and food intake reduced, blood aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), low-density lipoprotein-cholesterol (LDL-C) decreased, whereas high-density lipoprotein cholesterol (HDL-C) increased. Histopathology showed that steatosis and inflammation scores were reduced within the liver and adipocyte sizes were reduced within epididymal adipocyte. In addition, a significant decrease in blood insulin and hepatic TG and a significant increase in blood adiponectin were also confirmed. The results of western blot and qPCR in week 12, showed a significant decrease in the mRNA and protein levels of C/EBPα, and the mRNA levels of PPARγ in the liver. CONCLUSION: Dark tea extracts are thought to have an anti-obesity effect by reducing the levels of the main transcription factors that promote adipocyte differentiation, such as C/EBPα, and PPARγ. Therefore, diet products using dark tea extracts could be developed.

Assessment of Individual Renal Function Using 99mTc-MAG3 Renography.

BACKGROUND/AIM: This study performed 99mTc-MAG3 renal scintigraphy on rabbit kidneys and evaluated its ability to identify obstructive or non-obstructive kidneys. MATERIALS AND METHODS: Renal function was assessed during a four-week post-obstruction period by obtaining planar images of 99mTc-MAG3 activity following an ear vein injection. The individual renal function was evaluated by renal scintigraphy in conjunction with histopathological and morphological examinations. RESULTS: The renal perfusion of 99mTc-MAG3 in the right kidney with a ureteral obstruction decreased with time. The width, height, and cortical thickness of the obstructed right kidney were significantly larger than those of the left kidney. A histopathological examination four weeks after the ureteral obstruction revealed a typical pattern of urinary tract obstruction, including multiple tubules, enlargement of the interstitial area, and cytoplasmic vacuoles. CONCLUSION: 99mTc-MAG3 renal scintigraphy provides the kidney shape and size and can identify potential obstructive and non-obstructive kidneys in rabbits.

Intraluminal Titanium Alloy Stent to Prevent Tracheal Stenosis in Tracheal Anastomosis.

BACKGROUND/AIM: Tracheal stenosis can cause respiratory problems in mature, small-breed dogs. This study aimed to evaluate the placement of an intratracheal titanium alloy stent to prevent tracheal stenosis in canine tracheal anastomosis. MATERIALS AND METHODS: The self-expandable intratracheal stent was an alloy of nickel and titanium, at the same atomic ratio. Vital signs and respiratory patterns, C-reactive protein, radiography, computed tomography, and endoscopy results after intraluminal stenting were assessed for 3-5 months. RESULTS: No dogs showed evidence of intraluminal tracheal stenosis or tracheitis in the region of stent insertion on tracheoscopy and computed tomography after tracheal stent placement. After 1-2 weeks of tracheal stent placement, all dogs resolved coughing and dyspnea signs and resumed normal activities. CONCLUSION: The intratracheal stent showed no movement or deformation in the trachea, and had flexibility and an appropriate radial force. Therefore, titanium alloy tracheal stents are useful in stenotic operations for tracheal reconstruction.

Evaluation of Renal Function in Obstructed Ureter Model Using 99mTc-DMSA.

BACKGROUND/AIM: Urinary obstruction is a condition of impaired urinary drainage, which may result in progressive renal deterioration. This study applied 99mTc-labeled dimercaptosuccinic acid (99mTc-DMSA) renal scintigraphy to a rabbit model of right ureter obstruction and evaluated its utility in studying obstructive renal diseases. MATERIALS AND METHODS: Complete unilateral ureter obstruction in rabbits was generated by complete ligation of the right ureter. Renal function was investigated during a 4-week post-obstruction period by obtaining planar images of 99mTc-DMSA activity following ear vein injection. Renal blood perfusion was evaluated by non-invasive scintigraphy in conjunction with parallel histological and hematological examinations. RESULTS: Renal perfusion was remarkably and rapidly reduced in the ureter-obstructed kidneys. During the experimental period, the size of left kidney appeared normal in the scintigraphic images, but the ureter-obstructed right kidney progressively became larger. Histopathological examination showed flattening and atrophy of tubules, enlargement of interstitial areas, accumulation of extracellular martices and infiltration of inflammatory cells in the obstreucted kidney. CONCLUSION: 99mTc-DMSA scintigraphy is a sensitive, non-invasive method to assess renal function in unilateral kidney diseases.

Osteogenic Evaluation of Hydroxyapatite Scaffold Loaded With Dexamethasone in Femoral Drill Holes.

BACKGROUND/AIM: Many cases of bone damage are due to trauma and metabolic diseases. This study aimed to evaluate bone regeneration into a porous hydroxyapatite (HA) scaffold using dexamethasone (DM)-loaded polymeric microspheres. MATERIALS AND METHODS: Four adult dogs were used to evaluate the in vivo performance of DM-loaded microspheres immobilized on the surfaces of porous HA scaffolds. Two 5-mm drill holes were created in both the left and right femurs of each dog. The experimental groups included a control group (drill holes filled with HA scaffold alone), a DM 20 group (holes filled with DM-loaded HA scaffold with 20 mg DM per scaffold), and a DM 100 group (hole filled with DM-loaded HA scaffold with 100 mg DM per scaffold). Resulting bone volume percentages and bone mineral densities were calculated by examing micro-computed tomographic (CT) images. RESULTS: The DM-loaded HA scaffold groups showed a gradual periosteal reaction two weeks after insertion of the HA scaffold into the femoral drill holes. Four weeks after HA scaffold insertion, the periosteal reaction in the femoral drill holes became denser. Eight weeks after insertion of DM-loaded HA scaffolds, clear images of the scaffold were observed in micro-CT images of the femoral drill hole. The DM 100 group had better bone healing tendencies (bone mineral density, bone mass, trabecular volume, bone surface, and trabecular thickness) than the DM 20 group. CONCLUSION: DM-loaded HA scaffolds are suitable platforms for distributing bioactive molecules during osteogenesis in femoral drill holes.

Evaluation of Goose-beak Bone Particles for Dentoalveolar Reconstruction in Dogs.

BACKGROUND/AIM: Tooth extraction is a common procedure in dental clinics. Tooth extraction can destroy gingiva, alveolar bone, periodontal ligaments and cement. If dental sockets are left as extracted, it will result in loss of teeth, as well as voice and aesthetic problems. A natural hydroxyapatite (HA) bioceramic bone graft substitute developed from goose-beak bone particles (GBPs) was used for dentoalveolar reconstruction in a canine model. MATERIALS AND METHODS: Four adult (18-22 months old) male beagle dogs weighing 8.2-9.6 kg were included in the study. Eight alveolar extraction sockets in the four dogs were divided randomly into two groups and a split-mouth design was established; control group, socket filled with commercial synthetic HA; tested group, socket filled with granulated GBP. RESULTS: Micro-CT analysis and hematoxylin and eosin and Masson's trichrome staining of non-decalcified sections were undertaken. Examination revealed that dentoalveolar reconstruction was initiated from the periphery of the host bone, and newly formed bone was well integrated with the GBP. Bone apposition was observed at the edge of the host bone-GBP interface. CONCLUSION: A natural ceramic powder obtained from GBP is suitable for use in dentoalveolar reconstruction in dogs.

Reversing Effect of Insulin on Local Anesthetics-Induced Sciatic Nerve Block in Rats.

BACKGROUND: Local anesthetics are used in various purposes from topical and infiltration anesthesia to peripheral nerve or central neural blockade. Even though local anesthetics are relatively safe, they can have some toxic and adverse effects. Prolonged sensory and motor block is another example of an unwanted complication. The primary objective of this study was to determine whether insulin has a reversal effect on the peripheral (sciatic) nerve block with lidocaine or bupivacaine. METHODS: The surgically exposed sciatic nerves in rats were blocked with lidocaine or bupivacaine, and then 0.1 ml of normal saline or 0.1 ml normal saline containing 0.1 IU a short-acting form of insulin was administrated per body in each group. Before and after sciatic nerve block, as well as until recovery from the nerve block after normal saline or insulin treatment, nerve conduction studies such as monitoring loss and recovery of the waveforms and amplitudes were performed to evaluate the status of motor nerve conduction. RESULTS: Complete recovery time of nerve conduction status in lidocaine + normal saline group was 58 ± 16 min, whereas that in lidocaine + insulin group was 17 ± 3 min and the difference was statistically significant (p < 0.01). Complete recovery time of nerve conduction status in bupivacaine + normal saline group was 116 ± 16 min and that in bupivacaine + insulin group was 36 ± 4 min and the two groups were significantly different (p < 0.01). CONCLUSIONS: Insulin can reverse peripheral nerve block induced by lidocaine or bupivacaine.

Osteogenic Evaluation of Goose-beak Bones According to Processing Temperature.

BACKGROUND/AIM: As an alternative material to autogenous bone, goose-beak bone particles (GBP) have been attracting great attention as a bone substitute due to their biological properties. This study was performed to assess bone generation using GBP in calvarial defects in a rat model. The study focus was the osteogenic potential of goose-beak bone at different processing temperatures. MATERIALS AND METHODS: There were three experimental groups: Control group (critical defect only), low-temperature (LT) group (filled with GBP heat-treated for 20 h at 400°C), and high-temperature (HT) group (filled with GBP heat-treated for 3 h at 1,200°C). RESULTS: The Ca/P atomic ratio of the goose-beak bone was 1.63, and the bones had a bony structure with open pores and interconnected rod-like struts. Micro-computed tomographic analysis revealed the quantity of new bone formation of the HT group was higher than that of the LT group. At 12 weeks after GBP insertion, new bone formation was significantly higher (p<0.05) in the HT group, and there were more new osteocytes in the lacuna in the HT group than in the LT group. Thus, GBP treated at a high temperature formed more new bone than that treated at a low temperature. CONCLUSION: It can be concluded that HT-treated GBP is a graft material that can be effective in promoting bone formation.

Pig tracheal patchy xenotransplantation in the dog.

BACKGROUND: A long-segmental tracheal lesion is difficult to repair by tracheal allotransplantation due to the lack of a well-defined blood supply for blood vessel anastomosis. The donor trachea needs to be revascularized within a well-vascularized soft tissue flap for several months to allow successful trachea allotransplantation. To date, xenotransplantation using the wild-type or genetically modified pig has been widely studied. The object of this study was to evaluate the feasibility of a small-sized (2 × 2 cm) wild-type pig tracheal patchy in a dog tracheal defect model before trying a long-segment tracheal defect model and using a genetically modified pig as a donor in dog xenotransplantation. METHOD: Three healthy beagle dogs (8-9 kg) were used as recipients, and one pig (20 kg) was used as the donor. A pig cartilaginous tracheal patchy (2 × 2 cm half tube) was sutured to the tracheal resected site in each dog. Antithymocyte globulin (2.5 mg/kg infusion, D0 and 1), tacrolimus (4.5 mg/kg, twice a day for 2 months), and methylprednisolone sodium succinate (1 mg/kg, IV, for 2 days and tapering) were administered for immunosuppression. The levels IL-2 and IFN-γ in the serum were measured at D0, 7, and 28. Tracheoscopy was performed at D28, 60, and 90. The recipients were sacrificed at D90, and the expression of dog and pig genes in the graft was evaluated by PCR. Histopathological examination of the graft was conducted. RESULTS: All of the dogs survived without complications during the experimental period. Their IL-2 and IFN-γ levels were significantly increased at D7 after transplantation compared to D0 and D28 (P < 0.05). The pig tracheal patchy site was open, and no stenosis was observed until D90 on tracheoscopy, when pale mucosa erosion was observed; there was also remnant suture material at D28. However, the tracheal patchy sites gradually became similar to normal mucosa at D60 and 90. The expression of pig genes was detected in the graft by PCR. Normal epithelium and CD3 cells were observed in the histological examination at D90. CONCLUSION: In this study, our data suggest that the pig tracheal patchy can be successfully engrafted into the trachea of dog, although erosion of mucosa on the graft was seen at D30, in spite of the discordant species.

The Healing Effect of Platelet-rich Plasma (PRP) Jelly in Rabbits Undergoing Tracheal Resection and Anastomosis.

BACKGROUND/AIM: Tracheal anastomosis is commonly indicated for patients with tracheal tumor, stenosis and tracheoesophageal fistula. This study was designed to evaluate the healing activity of topical application of platelet-rich plasma (PRP) jelly for tracheal reconstruction in a rabbit model. MATERIALS AND METHODS: Thirty-six healthy New Zealand White rabbits were assigned to three groups of 12 animals each. The control group underwent tracheal resection and anastomosis. The fibrin-glue group and PRP-jelly group underwent tracheal resection and anastomosis plus fibrin glue or PRP jelly application over the anastomosis and surgical field, respectively. RESULTS: The PRP jelly treatment enhanced the healing capacity by positive effects on healing rate, tissue fill, and volume fraction of fibroblasts during the 28 days following surgery. CONCLUSION: Application of PRP jelly to tracheal anastomotic wounds can accelerate or improve the quality of repair.

Healing Effect of Platelet-rich Plasma on Decellularized Tracheal Allotransplantation in Rabbits.

BACKGROUND/AIM: The purpose of this study was to explore the effect of platelet-rich plasma (PRP) on enhancing healing of trachea allotransplantation and confirm the effect via parallel histological and tracheoscopic examinations in seven adult New Zealand White rabbits. MATERIALS AND METHODS: Harvested trachea was inserted into recipients with end-to-end anastomosis by a simple interrupted suture. PRP-treated rabbits were treated with 0.5 ml of PRP at the trachea grafts, while control rabbit allografts were treated with 0.5 ml of saline. RESULTS: Tracheoscopy of tracheal allografts treated with PRP revealed that the trachea was well healed with no stenosis. The healing effect in the PRP-treated rabbits increased tracheal activity and produced faster trachea regeneration compared to that in control rabbits. There was a good correlation between the subjective symptom of noisy breathing and the objective grading of tracheal stenosis. The tracheal allografts with suture materials appeared slightly pale and looked more like mucosa erosion than normal mucosa at four weeks post-surgery. Contact of trachea-to-transplanted grafts in PRP-treated rabbits was intimate with the surface of the transplanted region and showed high-density epithelialization. After 8 weeks, blood vessels were observed in the transplanted graft in PRP-treated rabbits. Normal epithelium was present in grafts at 8 weeks after allotransplantation. No CD20+ cells were detected in grafts but a few CD3+ cells were observed under the epithelium. CONCLUSION: The results of this study show that it is possible to perform tracheal reconstruction in rabbits treated with PRP after tracheal transplantation.

A rational tissue engineering strategy based on three-dimensional (3D) printing for extensive circumferential tracheal reconstruction.

Extensive circumferential tracheal defects remain a major challenging problem in the field of tracheal reconstruction. In this study, a tissue-engineered tracheal graft based on three-dimensional (3D) printing was developed for extensive circumferential tracheal reconstruction. A native trachea-mimetic bellows scaffold, a framework for a tissue-engineered tracheal graft, was indirectly 3D printed and reinforced with ring-shaped bands made from medical grade silicone rubber. A tissue-engineered tracheal graft was then created by stratifying tracheal mucosa decellularized extracellular matrix (tmdECM) hydrogel on the luminal surface of the scaffold and transferring human inferior turbinate mesenchymal stromal cell (hTMSC) sheets onto the tmdECM hydrogel layer. The tissue-engineered tracheal graft with critical length was anastomosed end-to-end to the native trachea and complete re-epithelialization was achieved on the entire luminal surface within 2 months in a rabbit model with no post-operative complications. With this successful result, the present study reports the preliminary potential of the tissue-engineered tracheal graft as a rational tissue engineering strategy for extensive circumferential tracheal reconstruction.

Vertical Bone Augmentation Using Three-dimensionally Printed Cap in the Rat Calvarial Partial Defect.

BACKGROUND/AIM: Lost alveolar bone is commonly restored by distraction osteogenesis or bone blocks for substantial vertical bone augmentation (VBA), that is applied in conjunction with a barrier system. This study was performed to determine whether volume control of a three-dimensional (3D) printed nylon cap in the rat calvarial partial thickness bone defect would induce qualitative and quantitative differences in vertical bone regeneration. MATERIALS AND METHODS: A rat calvarial partial thickness bone defect was prepared and the 3D cap covered the defect to induce VBA, while the control group was left without cap placement. After six weeks the animals were sacrificed, and the calvaria were prepared for micro-CT (µCT) and histology. RESULTS: Quantitative µCT results showed that our cap system has significant osteoconductive properties, and the histology slide revealed new bone filled inside the cap. CONCLUSION: The results clearly showed that this system was successful for VBA in a research animal model.

Immunological Compatibility of Bone Tissues from Alpha-1,3-galactosyltransferase Knockout Pig for Xenotransplantation.

We investigated whether the lack of galactosyltransferase (α-Gal) expression in bone tissue is associated with reduced immune response of human peripheral blood mononuclear cells (PBMCs) against pig bone tissue. When human PBMC obtained from heparinized blood of healthy volunteers was stimulated with bone extracts of pigs with α-1,3-galactosyltransferase knock out (α-Gal KO), the proliferation of human PBMCs and production of proinflammatory cytokines such as TNF-α and IL-1ß were significantly reduced compared to those stimulated with bone extracts of wild type (WT) pigs. In addition, activation of CD4+ helper T cells and production of IL-2, IFN-γ, and IL-17 were reduced upon stimulation with bone tissue extracts from α-Gal KO pigs. This is possibly due to the lowered activities of the NF-κB, p38, ERK, and JNK signaling pathways. Our findings can be used to evaluate the compatibility of bone tissues from α-Gal KO pigs with human bone grafting as novel natural biomaterials, thereby increasing the feasibility of future clinical applications.

Evaluation of Immunosuppressive Therapy Use for Tracheal Transplantation with Trachea-Mimetic Bellows Scaffolds in a Rabbit Model.

The objective of this study was to evaluate the use of immunosuppressive therapy with high-dose cyclosporine, high-dose azathioprine, and a combination of low-dose cyclosporine and azathioprine after tracheal reconstruction by using a trachea-mimetic graft of polycaprolactone (PCL) bellows-type scaffold in a rabbit model. Twenty-four healthy New Zealand white rabbits were used in the study. All underwent circumferential tracheal replacement using tissue-engineered tracheal graft, prepared from PCL bellows scaffold reinforced with silicone ring, collagen hydrogel, and human turbinate mesenchymal stromal cell (hTMSC) sheets. The control group (Group 1) received no medication. The three experimental groups were given daily cyclosporine intramuscular doses of 10 mg/kg (Group 2), azathioprine oral doses of 5 mg/kg (Group 3), and azathioprine oral doses of 2.5 mg/kg plus cyclosporine intramuscular doses of 5 mg/kg (Group 4) for 4 weeks or until death. Group 1 had longer survival times compared to Group 2 or Group 3. Each group except for Group 1 experienced decreases in amount of nutrition and weight loss. In addition, compared with the other groups, Group 2 had significantly increased serum interleukin-2 and interferon-γ levels 7 days after transplantation. The results of this study showed that the administration of cyclosporine and/or azathioprine after tracheal transplantation had no beneficial effects. Furthermore, the administration of cyclosporine had side effects, including extreme weight loss, respiratory distress, and diarrhea. Therefore, cyclosporine and azathioprine avoidance may be recommended for tracheal reconstruction using a native trachea-mimetic graft of PCL bellows-type scaffold in a rabbit model.

Cortisol Levels and Gastrointestinal Disorders After Stressful Surgery in Rabbits.

Rabbits are widely used in biomedical studies because they are docile and manageable. However, they are prone to gastrointestinal disorders due to their vulnerability to stress. Eighteen adult rabbits were used for allogenic tracheal surgery. The tracheas for allograft, 20-mm length, were transplanted into 20-mm tracheal defects. Immediately after surgery, most rabbits suffered from poor appetite. Food and water intake gradually recovered within 7 days after surgery, but six rabbits had severe anorexia from day 7 post-surgery. Four of these rabbits developed symptoms of diarrhea after surgery; three of them died several days after the onset of diarrhea, while one rabbit recovered. Gastrointestinal disorders need to be prevented in rabbits undergoing stressful surgery. Furthermore, it is important to choose the proper type and dose of analgesics in order to relieve postoperative pain. With this observation in mind, rabbits are not considered to be an appropriate model for stressful surgery.

Bone Regeneration of Hydroxyapatite with Granular Form or Porous Scaffold in Canine Alveolar Sockets.

This study was undertaken to assess bone regeneration using hydroxyapatite (HA). The primary focus was comparison of bone regeneration between granular HA (gHA) forms and porous HA (pHA) scaffold. The extracted canine alveolar sockets were divided with three groups: control, gHA and pHA. Osteogenic effect in the gHA and pHA groups showed bone-specific surface and bone mineral density to be significantly higher than that of the control group (p<0.01). Bone volume fraction, bone mineral density, and amount of connective tissue related to disturbing osseointegration of the gHA group was higher than in the pHA group. Quantity of new bone formation of the pHA group was higher than that of the gHA group. This study demonstrated that gHA and pHA are potentially good bone substitutes for alveolar socket healing. For new bone formation during 8 weeks' post-implantation, HA with porous scaffold was superior to the granular form of HA.

Effect of Hydrogen Dioxide Treatment on the Osteogenic Potential of Duck-beak Bone-derived Natural Bioceramic Microparticles.

BACKGROUND/AIM: As an alternative material to the autogenous bone, duck-beak bone particle for bone substitute have been attracting great attention due to their biological properties. To deliver the most favorable outcome of medical treatment, it is essential to study the effect of various processing methods of the duck-beak bone. In this study, we compared the two deproteinizing agents for manufacturing duck-beak bone. Group 1 was treated by a conventional chemical agent (ethylenediamine) and Group 2 by hydrogen dioxide (H2O2). In vitro and in vivo experiments were conducted in parallel to compare the cytocompatibility and osteogenic capability between two processing methods. For in vitro tests, human adipose-derived mesenchymal stem cells (hAD-MSCs) were planted onto each sample and their attachment and growing were evaluated. For in vivo biocompatibility and osteogenic properties, the samples were applied on the critical-sized calvarial bone defect of rats. Group 2 showed significantly higher cell attachment but Group1 showed slightly higher cell proliferation. In in vivo tests, all groups have shown biocompatibility and increased level of osteogenic potential. However, Group 2 had significantly higher bone regeneration (p<0.05). This experiment confirmed that H2O2 can be an optimal processing method for duck-beak bone particle.