This study was funded by grants from the National Natural Science Foundation of China 82101000 (H. W.), U21A20368 (L. Y.), and 82100982 (F. L.), and supported by Sichuan Science and Technology Program 2023NSFSC1499 (H. W.).

All animal procedures in this study were reviewed and approved by the Ethical Committee of the West China School of Stomatology, Sichuan University (WCHSIRB-D-2021-597). Sprague-Dawley rats (male, body weight 300 g) were used for the present study.
1. Presurgical preparation
<ol>
	<li>Instrument preparation
	<ol>
		<li>Refer to Figure 1A for the surgical instruments used in this study: electric shaver, tissue scissors, ophthalmic scissors, ophthalmic forceps, di...

Establishment and Evaluation of a Rat Femoral Box: Cavity Defect Model

<ol>
	<li>Einhorn, T. A., Gerstenfeld, L. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fracture+healing:+mechanisms+and+interventions.">Fracture healing: mechanisms and interventions.</a> Nat Rev Rheumatol. 11 (1), 45-54 (2015).</li><li>Claes, L., Recknagel, S., Ignatius, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fracture+healing+under+healthy+and+inflammatory+conditions.">Fracture healing under healthy and inflammatory conditions.</a> Nat Rev Rheumatol. 8 (3), 133-143 (2012).</li><li>Holmes, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nonunion+bone+fracture:+a+quicker+fix.">Nonunion bone fracture: a quicker fix.</a> Nature. 550 (7677), S193 (2017).</li><li>Dimitriou, R., Jones, E., McGonagle, D., Giannoudis, P. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bone+regeneration:+current+concepts+and+future+directions.">Bone regeneration: current concepts and future directions.</a> BMC Med. 9, 66 (2011).</li><li>Schmidt, A. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autologous+bone+graft:+Is+it+still+the+gold+standard?+Injury.">Autologous bone graft: Is it still the gold standard? Injury.</a> 52 (Suppl 2). , S18-S22 (2021).</li><li>Baldwin, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autograft,+allograft,+and+bone+graft+substitutes:+Clinical+evidence+and+indications+for+use+in+the+setting+of+orthopaedic+trauma+surgery.">Autograft, allograft, and bone graft substitutes: Clinical evidence and indications for use in the setting of orthopaedic trauma surgery.</a> J Orthop Trauma. 33 (4), 203-213 (2019).</li><li>Muscolo, D. L., Ayerza, M. A., Aponte-Tinao, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Massive+allograft+use+in+orthopedic+oncology.">Massive allograft use in orthopedic oncology.</a> Orthop Clin North Am. 37 (1), 65-74 (2006).</li><li>Yu, Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomimetic+periosteum-bone+substitute+composed+of+preosteoblast-derived+matrix+and+hydrogel+for+large+segmental+bone+defect+repair.">Biomimetic periosteum-bone substitute composed of preosteoblast-derived matrix and hydrogel for large segmental bone defect repair.</a> Acta Biomater. 113, 317-327 (2020).</li><li>Pearce, A. I., Richards, R. G., Milz, S., Schneider, E., Pearce, S. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+for+implant+biomaterial+research+in+bone:+a+review.">Animal models for implant biomaterial research in bone: a review.</a> Eur Cell Mater. 13, 1-10 (2007).</li><li>McGovern, J. A., Griffin, M., Hutmacher, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+for+bone+tissue+engineering+and+modelling+disease.">Animal models for bone tissue engineering and modelling disease.</a> Dis Model Mech. 11 (4), dmm033084 (2018).</li><li>Bigham-Sadegh, A., Oryan, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selection+of+animal+models+for+preclinical+strategies+in+evaluating+the+fracture+healing,+bone+graft+substitutes+and+bone+tissue+regeneration+and+engineering.">Selection of animal models for preclinical strategies in evaluating the fracture healing, bone graft substitutes and bone tissue regeneration and engineering.</a> Connect Tissue Res. 56 (3), 175-194 (2015).</li><li>Horner, E. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long+bone+defect+models+for+tissue+engineering+applications:+criteria+for+choice.">Long bone defect models for tissue engineering applications: criteria for choice.</a> Tissue Eng Part B Rev. 16 (2), 263-271 (2010).</li><li>Vajgel, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+systematic+review+on+the+critical+size+defect+model.">A systematic review on the critical size defect model.</a> Clin Oral Implants Res. 25 (8), 879-893 (2014).</li><li>Samsonraj, R. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+versatile+protocol+for+studying+calvarial+bone+defect+healing+in+a+mouse+model.">A versatile protocol for studying calvarial bone defect healing in a mouse model.</a> Tissue Eng Part C Methods. 23 (11), 686-693 (2017).</li><li>Yu, F., Li, F., Zheng, L., Ye, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epigenetic+controls+of+Sonic+hedgehog+guarantee+fidelity+of+epithelial+adult+stem+cells+trajectory+in+regeneration.">Epigenetic controls of Sonic hedgehog guarantee fidelity of epithelial adult stem cells trajectory in regeneration.</a> Sci Adv. 8 (29), eabn4977 (2022).</li><li>Colnot, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Skeletal+cell+fate+decisions+within+periosteum+and+bone+marrow+during+bone+regeneration.">Skeletal cell fate decisions within periosteum and bone marrow during bone regeneration.</a> J Bone Miner Res. 24 (2), 274-282 (2009).</li><li>Bhandari, M., Shaughnessy, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+minimally+invasive+percutaneous+technique+of+intramedullary+nail+insertion+in+an+animal+model+of+fracture+healing.">A minimally invasive percutaneous technique of intramedullary nail insertion in an animal model of fracture healing.</a> Arch Orthop Trauma Surg. 121 (10), 591-593 (2001).</li><li>Muschler, G. F., Raut, V. P., Patterson, T. E., Wenke, J. C., Hollinger, J. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+design+and+use+of+animal+models+for+translational+research+in+bone+tissue+engineering+and+regenerative+medicine.">The design and use of animal models for translational research in bone tissue engineering and regenerative medicine.</a> Tissue Eng Part B Rev. 16 (1), 123-145 (2010).</li><li>Clifford, J., Rosen, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Primer on the Metabolic Bone Diseases and Disorders of Mineral Metabolism. , (2019).</li><li>Wong, R. M. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+systematic+review+of+current+osteoporotic+metaphyseal+fracture+animal+models.">A systematic review of current osteoporotic metaphyseal fracture animal models.</a> Bone Joint Res. 7 (1), 6-11 (2018).</li></ol>

Preclinical animal models are vital for examining bone healing and the influence of biomaterials on bone regeneration. This protocol illustrates a femoral box-cavity defect model replicating the intramembranous bone formation process associated with clinical bone regeneration. The defect area was intraoperatively standardized using a pre-marked oral probe. Micro-CT and histopathological staining results showed progressive healing over 6 weeks, with thickened periosteum and new trabecular bone formation, followed by dense...

Fractured and defective bone often results from trauma, tumors, inflammation, and congenital malformations1,2. Although bone tissue in young healthy individuals typically possesses robust regenerative abilities3, defects exceeding a critical size or healing impediments due to systemic diseases (e.g., diabetes, osteoporosis, and infections) may still lead to complications such as bone discontinuity or impaired healing4. To address this clinical challenge, bone grafting or biomaterials are commonly used to replace severely defective bone or to reconstruct large bone segments. However, these treatments have limitations. For instance, although considered the gold standard, autologous bone grafting suffers from restricted donor supply and potential donor site complications5,6. Allografts also present certain risks, such as immune-mediated rejection, potential transmission of diseases, and negative impacts on the biomechanical and biological properties of the graft7.
Recent years have witnessed a surge in research focusing on bone defect healing mechanisms. The use of alternative biomaterials and advancements in tissue engineering have emerged as prominent topics within the domain of bone regeneration8. Before these biomaterials can be applied to human therapy, they must be tested in vitro and in vivo to ensure their efficacy and safety. However, the reduced complexity of in vitro environments and the absence of immune and inflammatory responses limit the evaluation of various biomaterials in vitro. Consequently, the establishment of animal models for various types of bone tissue defects is needed9. Animal models allow the evaluation of biomaterials under different loading conditions, facilitate understanding of species-specific bone characteristics, and provide insight into the similarity between animal models and human clinical situations. These advantages are essential for studying bone-scaffold interactions and translating research findings into clinical practice9,10.
Currently, mechanical bone defect animal models are widely used to validate the performance of biomaterials, with cranial bone defect models and segmental bone defect models being the most commonly applied methods11. Segmental bone defect models, often utilized to mimic severe long bone or tibial trauma ending in bone nonunion, are advantageous due to their uniform dimensions and defined anatomical positions, simplifying radiological or histological evaluations of new bone formation and revascularization. However, these models require metal implants to stabilize bilateral fracture segments and necessitate a complex healing process involving both endochondral and intramembranous ossification12. On the other hand, calvarial bone defect models have become a primary screening tool for evaluating biomaterials due to their standardized defect diameters, convenient surgical access, and the supportive function of dura mater and soft tissue13. Although they are widely used for modeling intramembranous bone formation in clinically relevant scenarios, they are unsuitable for evaluating bone healing under biomechanical loading conditions due to their non-load-bearing nature during the healing process14.
To address these limitations, we established a box-cavity cortical bone defect model in the femoral diaphysis tissue of rats. Utilizing micro-computed tomography (CT) three-dimensional (3D) reconstruction, and histopathological staining (Hematoxylin and eosin [HE] and Masson), we analyzed the healing process of this model under hemostasis conditions. We aim to offer fresh insights for evaluating biomaterial performance under biomechanical loading conditions and for studying the bioengineering and mechanism of bone regeneration vis-&#224;-vis intramembranous ossification.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>1.2 mm slow speed ball drill</td>
			<td>Dreybird Medical Equipment Co., Ltd.</td>
			<td>RA3-012</td>
			<td>For preparation of box cavity defects</td>
		</tr>
		<tr>
			<td>3.0 suture</td>
			<td>Chengdu Shifeng Co., Ltd.</td>
			<td>None</td>
			<td>For suturing wounds</td>
		</tr>
		<tr>
			<td>4% paraformaldehyde</td>
			<td>Biosharp</td>
			<td>BL539A</td>
			<td>For fix the femoral specimens</td>
		</tr>
		<tr>
			<td>Cotton balls</td>
			<td>Haishi Hainuo Group Co.,&#160; Ltd.</td>
			<td>20120047</td>
			<td>For skin sterilization and cleaning of surgical field</td>
		</tr>
		<tr>
			<td>Cotton sticks</td>
			<td>Lakong Medical Devices Co., Ltd.</td>
			<td>M6500R</td>
			<td>For skin disinfection</td>
		</tr>
		<tr>
			<td>Dental technician grinding machine</td>
			<td>Marathon</td>
			<td>N3-140232</td>
			<td>For preparation of box cavity defects</td>
		</tr>
		<tr>
			<td>Disposable scalpel</td>
			<td>Hangzhou Huawei Medical Supplies Co., Ltd.</td>
			<td>20100227</td>
			<td>For creating skin incisions as well as to sharply separate muscle tissue</td>
		</tr>
		<tr>
			<td>Electric shaver</td>
			<td>JASE</td>
			<td>BM320210</td>
			<td>Removal of hair tissue from the surgical area</td>
		</tr>
		<tr>
			<td>Hematoxylin and Eosin Stain kit</td>
			<td>Biosharp</td>
			<td>C1005</td>
			<td>For the histological analysis of the specimens</td>
		</tr>
		<tr>
			<td>Masson&#8217;s Trichrome Stain Kit</td>
			<td>Solarbio</td>
			<td>G1340</td>
			<td>For the histological analysis of the specimens</td>
		</tr>
		<tr>
			<td>Micro CT</td>
			<td>Scanco medical ag</td>
			<td>&#181;CT 45</td>
			<td>For analyzing the healing of defects in femoral samples</td>
		</tr>
		<tr>
			<td>Needle holder</td>
			<td>Chengdu Shifeng Co., Ltd.</td>
			<td>None</td>
			<td>For suture-holding needles</td>
		</tr>
		<tr>
			<td>Olympus Research Grade Whole Slide Scanning System VS200</td>
			<td>Chengdu Knowledge Technology Co.</td>
			<td>VS200</td>
			<td>For analyzing the results of HE staining and Masson staining</td>
		</tr>
		<tr>
			<td>Ophthalmic forceps</td>
			<td>Chengdu Shifeng Co., Ltd.</td>
			<td>None</td>
			<td>For clamping skin, muscle tissue</td>
		</tr>
		<tr>
			<td>Ophthalmic scissors</td>
			<td>Chengdu Shifeng Co., Ltd.</td>
			<td>None</td>
			<td>For forming a skin incision approach</td>
		</tr>
		<tr>
			<td>Oral low-speed handpiece</td>
			<td>Marathon</td>
			<td>Y221101003</td>
			<td>For preparation of box cavity defects</td>
		</tr>
		<tr>
			<td>Oral probe</td>
			<td>Shanghai Sangda Medical Insurance Co., Ltd.</td>
			<td>20000143</td>
			<td>For measuring the diameter of defects</td>
		</tr>
		<tr>
			<td>Periosteal separator</td>
			<td>Chengdu Shifeng Co., Ltd.</td>
			<td>None</td>
			<td>For blunt separation of muscle tissue</td>
		</tr>
		<tr>
			<td>Sprague&#8211;Dawley rats</td>
			<td>Byrness Weil Biotech Ltd</td>
			<td>None</td>
			<td>For the establishment of femoral bone boxy cavitary defect</td>
		</tr>
		<tr>
			<td>Tissue scissors</td>
			<td>Chengdu Shifeng Co., Ltd.</td>
			<td>None</td>
			<td>For forming a skin incision approach</td>
		</tr>
	</tbody>
</table>

creating a box-cavity defect model in the cortical bone of rat femora

Severe bone defects or complex fractures can result in serious complications such as nonunion or insufficient bone healing. Tissue engineering, which involves the application of cells, scaffolds, and cytokines, is considered a promising solution for bone regeneration. Consequently, various animal models that simulate bone defects play a crucial role in exploring the therapeutic potential of tissue engineering for bone healing. In this study, we established a box-shaped cortical bone defect model in the mid-femur of rats, which could serve as an ideal model for assessing the function of biomaterials in promoting bone healing. This box-shaped cortical bone defect was drilled using an oral low-speed handpiece and shaped by a lathe needle. Post-operative micro-CT analysis was immediately conducted to confirm the successful establishment of the box-cavity cortical bone defect. The femurs on the operated side of the rats were then harvested at multiple time points post-surgery (0 days, 2 weeks, 4 weeks, and 6 weeks). The healing process of each sample&#39;s defect area was evaluated using micro-CT, hematoxylin and eosin (H&#38;E) staining, and Masson trichrome staining. These results demonstrated a healing pattern consistent with intramembranous ossification, with healing essentially complete by 6 weeks. The categorization of this animal model&#39;s healing process provides an effective in vivo method for investigating novel biomaterials and drugs that target intramembranous ossification during bone tissue defect healing.

Author Spotlight: The Box-Cavity Cortical Approach for Enhanced Evaluation of Biomaterials and Bone Regeneration

Creating a Box-Cavity Defect Model in the Cortical Bone of Rat Femora

Various animal models with bone defects are applied in exploring the therapeutic potential of tissue engineering for bone healing. However, most of them are unable to generate standard defects under biomechanical loading conditions, which is important in evaluating the bone healing effect of bio materials. Compared to traditional bone defect models, the recent box cavity cortical bone defect model offers significant advancements.It not only provides a standardized bone defect size for more accurate quantification of bone healing, but also allows for the assessment of bio materials under biomechanical loading conditions without the need for additional fixation. Our protocol provides a comprehensive and generalizable approach for investigating intramembranous bone formation within in vivo study of bone regeneration models. This is particularly beneficial for the field of bone tissue engineering.

In this protocol, we successfully establish a rat femoral box-cavity defect model with dimensions of 4.5 mm x 1.5 mm by drilling. In order to analyze the healing process, we collected the femoral tissue on the operated side at 0 days, 2 weeks, 4 weeks, and 6 weeks after surgery, which are the key time points of endochondral ossification, intramembranous ossification, and bone remodeling during the healing process of femoral trauma in rats2. On post-operative day 0,...

Watch this Scientific Journal Video about Creating a Box-Cavity Defect Model in the Cortical Bone of Rat Femora at JoVE.com

Here, we present a protocol for creating a box-cavity defect in rat femoral diaphysis tissue. This model can assess biomaterial performance under biomechanical stress and explore mechanisms of bone regeneration related to intramembranous osteogenesis.

Severe bone defects or complex fractures can result in serious complications such as nonunion or insufficient bone healing. Tissue engineering, which ...

creating-a-box-cavity-defect-model-in-the-cortical-bone-of-rat-femora

Research

JoVE Journal

Medicine

413 Views.  West China Hospital of Stomatology, Sichuan University. Various animal models with bone defects are applied in exploring the therapeutic potential of tissue engineering for bone healing. However, most of them are unable to generate standard defects under biomechanical loading conditions, which is important in evaluating the bone healing effect of bio materials. Compared to traditional bone defect models, the recent box cavity cortical bone defect model offers significant advancements.It not only provides a standardized bone defect size for ...

Video: Author Spotlight: The Box-Cavity Cortical Approach for Enhanced Evaluation of Biomaterials and Bone Regeneration

Here, we present a protocol for creating a box-cavity defect in rat femoral diaphysis tissue. This model can assess biomaterial performance under biomechanical stress and explore mechanisms of bone regeneration related to intramembranous...

https://cloudfront.jove.com/CDNSource/teasers/66068_b.jpg

biological compatibility profile on biomaterials for bone regeneration

Biological Compatibility Profile on Biomaterials for Bone Regeneration

The number of novel biomaterials engineered for repairing large bone lesions is continuously expanding with the aim to enhance bone healing and overcome the complications associated with bone transplantation. Here, we present a multidisciplinary strategy for pre-clinical biocompatibility testing of biomaterials for bone...

integrated bone formation through in vivo endochondral ossification using mesenchymal stem cells

Author Spotlight: Enhancing Bone Regeneration with Vascularized Artificial Cartilage Integration 

Bone therapy via endochondral ossification by implanting artificial cartilage tissue produced from mesenchymal stem cells has the potential to circumvent the drawbacks of conventional therapies. Hyaluronic acid hydrogels are effective in scaling up uniformly differentiated cartilage grafts as well as creating integrated bone with vascularization between fused grafts in...

Artificial Cartilage Implants for Bone Regeneration via Endochondral Ossification

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comprehensive characterization of tissue mineralization in an ex vivo model

Author Spotlight: Advanced Techniques for Characterizing Tissue Mineralization in Bone Regeneration Research

The proposed protocol entails a global approach to assess bone formation in the context of bone regeneration using multimodal analyses. It aims to provide qualitative and quantitative information on new bone formation, enhancing the rigor and validity of basic and pre-clinical...

Multimodal Analysis of Bone Formation Using Explant Models

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two-photon laser-mediated ablation of osteoblasts in developing zebrafish larvae

Author Spotlight: Immune-Mediated Bone Regeneration &#8212; The Critical Role of Macrophages and Controlled Immunomodulation in Restorative Processes

This protocol describes a two-photon laser ablation approach carried out in zebrafish larvae, which serves as a model to study bone regeneration and the effects of the immune response to...

Laser Ablation Method to Study Bone Regeneration in Zebrafish Larvae

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rat femoral diaphysis box-cavity creation

Rat Femoral Diaphysis Box-Cavity Creation

improved hysteroscopic resection of endometrial polyps using 6-fr micro-scissors and forceps

Author Spotlight: A Reproductive Hysteroscopy Approach for Complete Endometrial Polyp Removal and Enhanced Endometrial Receptivity

The novel technique presented here employs a combination of 6-Fr micro-scissors and forceps for hysteroscopic treatment of endometrial polyps, demonstrating encouraging outcomes for infertile patients afflicted with this...

Hysteroscopic Technique with Micro-Scissors and Forceps for Polyp Removal

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evaluation of biomaterials for bladder augmentation using cystometric analyses in various rodent models

Evaluation of Biomaterials for Bladder Augmentation using Cystometric Analyses in Various Rodent Models

Surgical stages of bladder augmentation are described using 3-D scaffolds in murine and rat models.  To test the efficacy of biomaterial configurations for use in bladder augmentation, techniques for both awake and anesthetized cystometry are...

studying the biology of bone regeneration using two-photon laser ablation approach in zebrafish larvae

Studying the Biology of Bone Regeneration Using Two-Photon Laser Ablation Approach in Zebrafish Larvae

use of human perivascular stem cells for bone regeneration

Use of Human Perivascular Stem Cells for Bone Regeneration

Human perivascular stem cells (PSCs) are a novel stem cell class for skeletal tissue regeneration similar to mesenchymal stem cells (MSCs). PSCs can be isolated by FACS (fluorescence activated cell sorting) from adipose tissue procured during standard liposuction procedures, then combined with an osteoinductive scaffold to achieve bone formation in...

stabilizing a femur osteotomy with a plate fixation in ambystoma mexicanum

Author Spotlight: Exploring Regeneration in Axolotls Through Insights in Cellular and Molecular Mechanisms, Bone Healing, and Implications for Human Therapies

A protocol for femoral osteotomy surgery with the use of internal plate fixation in mature axolotls is presented. The procedure can be used to perform comparative studies on limb regeneration and fracture healing in aquatic...

Using Plate Fixation to Study Bone Healing and Limb Regeneration in Axolotls

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application of laparoscopic partial splenectomy with total blood flow occlusion in benign splenic lesions

Author Spotlight: Enhanced Safety and Efficacy in Laparoscopic Partial Splenectomy - A Novel Approach with the Habibi4X Radiofrequency Device

In this study, we describe an intraoperative hemorrhage control technique for laparoscopic partial splenectomy, improving spleen resection's safety and...

Optimized Hemorrhage Control Method for Laparoscopic Partial Splenectomy

extended 78&#37; hepatectomy in a mouse surgical model

Author Spotlight: Evaluating Therapeutic Strategies to Enhance Liver Regeneration

The mouse model of partial 2/3 (66%) hepatectomy is well described in the literature, but more extended hepatectomies mimicking small-for-size syndrome after liver transplantation have seldom been used. We describe an extended 78% hepatectomy procedure in a mouse model that results in approximately 50% postoperative lethality in healthy mice.

Mouse Extended Hepatectomy Model for Liver Regeneration Studies

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zebrafish scale regeneration in toto and ex vivo culture of scales

Author Spotlight: Use of Fish Scales for Bone Remodeling Research &amp;#8211; Advancements in Ex Vivo Imaging and Dissecting Cell Interactions

This protocol describes the harvesting and visualization of elasmoid scales of zebrafish during in vivo regeneration. In addition, the ex vivo culture of these scales for up to 7 days after harvest is...

Harvesting and Visualization of Elasmoid Scales of Zebrafish During In Vivo Regeneration

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accessing the cytotoxicity and cell response to biomaterials

Accessing the Cytotoxicity and Cell Response to Biomaterials

This methodology aims to evaluate biomaterial cytotoxicity through the preparation of soluble extracts, using viability assays and phenotypic analysis, including flow cytometry, RT-PCR, immunocytochemistry, and other cellular and molecular biology...

trabecular bone microarchitecture evaluation in an osteoporosis mouse model

Author Spotlight: An Economic and Efficient Method for Quantitative Evaluation of Bone Microarchitecture in a Murine Osteoporosis Model 

This protocol presents an economical and efficient method for quantitative evaluation of bone microarchitecture in a mouse model of osteoporosis by combining Hematoxylin-Eosin (HE) staining and micro-computed tomography (Micro-CT)...

HE Staining and Micro-CT to Evaluate Murine Trabecular Bone Microarchitecture

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big box biochar kiln operation and best practices

Installation of the Big Box Biochar Kiln for Biochar Production

The Utah Biomass Resources Group (UBRG) has scaled-up simple biochar kilns in an innovative approach to hazardous fuel reduction and biochar production using metal boxes, called Big Box kilns, that allow for in-woods biochar production.  This article outlines Big Box biochar kiln operation and best...

Operating a Large Biochar Kiln and Implementing Best Practices

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advanced abdominal aortic aneurysm modeling in mice by combination of topical elastase and oral &#223;-aminopropionitrile

Author Spotlight: Enhanced Murine AAA Model Using Elastase to Mimic Human Aneurysms

This protocol describes a methodical surgical approach to modeling advanced abdominal aortic aneurysms in mice by a combination of directly applying elastase to the infrarenal aorta and administering &#223;-aminopropionitrile through drinking water.

Abdominal Aortic Aneurysm Development in Mice Using the Elastase and BAPN Method

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To begin place the anesthetized rat in a lateral recumbent position on the sterile surgical table. Remove the lower limb hairs with an electric shaver. Disinfect the surgical area in a circular motion with 5%iota four solution, followed by 75%alcohol.After locating the proximal and distal femur, make a 2.5 centimeter incision along the long axis of the femur to cut through the skin tissue. Using ophthalmic forceps and tissue scissors, separate the skin layer from the fascia. Expose the lateral approach to the femur through the biceps femurs and lateral femoral muscles.Locate the intersection of the two muscle septa and carefully separate with a disposable surgical blade along the muscle border until the femoral surface is reached. Next, apply a periosteal separator to bluntly separate the femoral surface muscles and expose the middle of the femoral diaphysis. Using a sterile marker pen, mark the area of the defect site on the mids surface of the femoral diaphysis.Next, using an oral low speed handpiece drill a small hole perpendicular to the bone surface at the marked site, destroying the periosteum and bone cortex to depth reaching the bone marrow cavity. Expand the hole in all directions to achieve a box cavity shape. Now hold a labeled oral probe parallel to the edge of the defect to determine the defect diameter and morphology.Suture to close the muscle and skin layers. Finally, disinfect the surgical area with 5%iota four from the inside out.