Zn–0.8Mg–0.2Sr (wt.%) Absorbable Screws—An In-Vivo Biocompatibility and Degradation Pilot Study on a Rabbit Model

In this pilot study, we investigated the biocompatibility and degradation rate of an extruded Zn–0.8Mg–0.2Sr (wt.%) alloy on a rabbit model. An alloy screw was implanted into one of the tibiae of New Zealand White rabbits. After 120 days, the animals were euthanized. Evaluation included clinical assessment, microCT, histological examination of implants, analyses of the adjacent bone, and assessment of zinc, magnesium, and strontium in vital organs (liver, kidneys, brain). The bone sections with the implanted screw were examined via scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS). This method showed that the implant was covered by a thin layer of phosphate-based solid corrosion products with a thickness ranging between 4 and 5 µm. Only negligible changes of the implant volume and area were observed. The degradation was not connected with gas evolution. The screws were fibrointegrated, partially osseointegrated histologically. We observed no inflammatory reaction or bone resorption. Periosteal apposition and formation of new bone with a regular structure were frequently observed near the implant surface. The histological evaluation of the liver, kidneys, and brain showed no toxic changes. The levels of Zn, Mg, and Sr after 120 days in the liver, kidneys, and brain did not exceed the reference values for these elements. The alloy was safe, biocompatible, and well-tolerated.

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A Novel Synthesized Sulfonamido-Based Gallate-JEZTC Blocks Cartilage Degradation on Rabbit Model of Osteoarthritis: An in Vitro and in Vivo Study

Cellular Physiology and Biochemistry ◽

10.1159/000493832 ◽

2018 ◽

Vol 49 (6) ◽

pp. 2304-2319 ◽

Cited By ~ 1

Author(s):

Zhenhui Lu ◽

Qin Liu ◽

Lei Liu ◽

Huayu Wu ◽

Li Zheng ◽

...

Keyword(s):

Signaling Pathways ◽

Cruciate Ligament ◽

Interleukin 1 ◽

Rabbit Model ◽

Cartilage Degradation ◽

Tissue Inhibitor Of Metalloproteinase ◽

Histological Evaluation ◽

Chondrocyte Apoptosis

Background/Aims: 3, 4, 5-trihydroxy-N-{4-[(5-methylisoxazol-3-yl) sulfamoyl] phenyl} benzamide (JEZTC), synthesized from gallic acid (GA) and sulfamethoxazole (SMZ), was reported with chondroprotective effects. However, the effects of JEZTC on osteoarthritis (OA) are still unclear. The goal of this study was to investigate the anti-osteoarthritic properties of JEZTC on interleukin-1-beta (IL-1β) stimulated chondrocytes in vitro and a rabbit anterior cruciate ligament transaction (ACLT) OA model in vivo. Methods: Changes in matrix metalloproteinases (MMPs) and apoptosis genes (bax, caspase 3 and tnf-α) and OA-specific protein (MMP-1) expression in vitro and in vivo were detected by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemistry. The production of reactive oxygen species (ROS) were investigated upon the treatment of JEZTC in chondrocytes processed with IL-1β in vitro and OA in vivo. Effect of JEZTC on OA was further studied by the macroscopic and histological evaluation and scores. The key proteins in signaling pathways inMAPK/P38, PI3KAkt and NF-κB also determined using western blot (WB) analysis. Results: JEZTC could significantly suppress the expression of MMPs and intracellular ROS, while meaningfully increase the gene expression of tissue inhibitor of metalloproteinase-1 (TIMP-1). Moreover, there was less cartilage degradation in JEZTC group compared with the phosphate-buffered saline (PBS) group in vivo. Results also indicated that JEZTC exerts effect on OA by regulating MAPKs and PI3K/Akt signaling pathways to activate NF-κB pathway, leading to the down-regulation of MMPs. The chondro-protective effect of JEZTC may be related with its ability to inhibit chondrocyte apoptosis by reduction of ROS production. Conclusion: JEZTC may be a possible therapeutic agent in the treatment of OA.

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Biomimetic aggrecan molecularly engineers articular cartilage following intra-articular injection in an OA rabbit model in vivo: a pilot study

Frontiers in Bioengineering and Biotechnology ◽

10.3389/conf.fbioe.2016.01.02748 ◽

2016 ◽

Vol 4 ◽

Author(s):

Phillips Evan ◽

Galindo Diego ◽

Bui Mickey ◽

Huneke Richard ◽

Reimold Emily ◽

...

Keyword(s):

Articular Cartilage ◽

Pilot Study ◽

Rabbit Model

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In vitro and in vivo effectiveness of a novel injectable calcitonin-loaded collagen/ceramic bone substitute

Journal of Biomaterials Applications ◽

10.1177/0885328221989984 ◽

2021 ◽

pp. 088532822198998

Author(s):

Karl Wu ◽

Yu-Chun Chen ◽

Shang M Lin ◽

Chih-Hung Chang

Keyword(s):

Calcium Phosphate ◽

Bone Cement ◽

Degradation Rate ◽

Rabbit Model ◽

Type I ◽

Calcium Phosphate Bone Cement ◽

Osteogenic Effect ◽

Composite Bone

This study aimed to evaluate the effectiveness of a novel calcitonin-loaded calcium phosphate composite bone cement in vitro and in vivo. The novel composite bone cements were composed of NuROs injectable bone graft substitute, type I collagen, and/or salmon calcitonin. The setting time, porosity, wettability, compressive strength, compressive modulus, and crystallographic structures of cement specimens were determined. Degradation rate, calcitonin release rate, and osteoinductivity were assessed in vitro. In addition, osteogenic effect was examined in a rabbit model of femoral defect. The results revealed that addition of collagen/calcitonin did not substantially alter physical properties and degradation rate of bone cement specimens. Calcitonin was released into culture medium in a two-phase manner. Osteogenic effect of conditioned medium derived from calcitonin containing bone cement was observed. Finally, de novo bone growth and bone mineralization across the bone defect area were observed in rabbits after implantation of composite bone cement specimens. In conclusion, this novel calcitonin-loaded composite calcium phosphate bone cement exhibits biocompatibility, bioresorbability, osteoinductivity, and osteoconductivity, which may be suitable for clinical use.

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Comparison between Sandblasted Acid-Etched and Oxidized Titanium Dental Implants: In Vivo Study

International Journal of Molecular Sciences ◽

10.3390/ijms20133267 ◽

2019 ◽

Vol 20 (13) ◽

pp. 3267 ◽

Cited By ~ 9

Author(s):

Eugenio Velasco-Ortega ◽

Ivan Ortiz-García ◽

Alvaro Jiménez-Guerra ◽

Loreto Monsalve-Guil ◽

Fernando Muñoz-Guzón ◽

...

Keyword(s):

Residual Stress ◽

Dental Implants ◽

Rabbit Model ◽

Chemical Properties ◽

In Vivo Study ◽

Implant Surface ◽

Bone Response ◽

Etched Surface ◽

Titanium Dental Implants

The surface modifications of titanium dental implants play important roles in the enhancement of osseointegration. The objective of the present study was to test two different implant surface treatments on a rabbit model to investigate the osseointegration. The tested surfaces were: a) acid-etched surface with sandblasting treatment (SA) and b) an oxidized implant surface (OS). The roughness was measured by an interferometeric microscope with white light and the residual stress of the surfaces was measured with X-ray residual stress Bragg–Bentano diffraction. Six New Zealand white rabbits were used for the in vivo study. Implants with the two different surfaces (SA and OS) were inserted in the femoral bone. After 12 weeks of implantation, histological and histomorphometric analyses of the blocks containing the implants and the surrounding bone were performed. All the implants were correctly implanted and no signs of infection were observed. SA and OS surfaces were both surrounded by newly formed trabeculae. Histomorphometric analysis revealed that the bone–implant contact % (BIC) was higher around the SA implants (53.49 ± 8.46) than around the OS implants (50.94 ± 16.42), although there were no significant statistical differences among them. Both implant surfaces (SA and OS) demonstrated a good bone response with significant amounts of newly formed bone along the implant surface after 12 weeks of implantation. These results confirmed the importance of the topography and physico–chemical properties of dental implants in the osseointegration.

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Histological and Histomorphometric Comparison of Innovative Dental Implants Laser Obtained: Animal Pilot Study

Materials ◽

10.3390/ma14081830 ◽

2021 ◽

Vol 14 (8) ◽

pp. 1830

Author(s):

Mastrangelo Filiberto ◽

Botticelli Daniele ◽

Bengazi Franco ◽

Scarano Antonio ◽

Piattelli Adriano ◽

...

Keyword(s):

Pilot Study ◽

Surface Characteristics ◽

Objective Evaluation ◽

Poor Quality ◽

Histomorphometric Analysis ◽

Implant Surface ◽

Bone Response ◽

Bone To Implant Contact ◽

Titanium Surfaces

Objective: Evaluation of the in vivo bone response of two innovative titanium surfaces ytterbium laser active fiber obtained (L1-L2) compared to a sandblasted and acid etched (SBAE) during early phase of osseointegration. Material and Methods: Three implant groups with the same macroscopic features were obtained (L1-L2-SBAE) to promote specific surface characteristics. Scanning electron microscopy, profilometric evaluation, X-ray spectrometry, and diffraction analysis were performed. For each group, six implants were placed in the tibiae of three Peli Buey sheep, and histologic, histomorphometric analysis, bone to implant contact (BIC), and the Dynamic Osseointegration index (DOI) were performed. Results: During the early phases of osseointegration, the histological and histomorphometric results showed significant differences between L1-L2-SBAE implants. At 15 and 30 days, histological analysis detected a newly bone formation around all specimens with an higher vital bone in L2 compared to L1 and SBAE both in cortical and in poor-quality marrow bone. At same time, histomorphometric analysis showed significantly higher BIC values in L2 (42.1 ± 2.6 and 82.4 ± 2.2) compared to L1 (5.2 ± 3.1 and 56.2 ± 1.3) and SBAE (23.3 ± 3.9 and 77.3 ± 0.4). DOI medium value showed a higher rate in L2 (2.83) compared to SBAE (2.60) and L1 (1.91). Conclusions: With the limitations of this pilot study, it is possible to assess that the titanium surface characteristics, and not the technologies used to obtain the modification, played a crucial role during the osseointegration process. Histological, histomorphometric, BIC, and DOI evaluation showed a significantly higher rate in L2 specimens compared to others, confirming that the implant surface could increase the bone response in cortical or marrow poor quality bone during the initial phases of osseointegration.

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Fully Implanted Prostheses for Musculoskeletal Limb Reconstruction after Amputation: An In Vivo Feasibility Study

10.1101/2020.07.02.184994 ◽

2020 ◽

Author(s):

Patrick T. Hall ◽

Samantha Z. Bratcher ◽

Caleb Stubbs ◽

Rebecca E. Rifkin ◽

Remi M. Grzeskowiak ◽

...

Keyword(s):

Rabbit Model ◽

Surgical Care ◽

Biological Tissues ◽

Medullary Canal ◽

The Body ◽

Surgical Incision ◽

New Zealand White Rabbits ◽

Future Work ◽

Limb Prosthesis

AbstractPrevious prostheses for replacing a missing limb following amputation must be worn externally on the body. This limits the extent to which prostheses could physically interface with biological tissues, such as muscles, to enhance functional recovery. The objectives of our study were to (1) test the feasibility of implanting a limb prosthesis, or endoprosthesis, entirely within living skin at the distal end of a residual limb, and (2) identify effective surgical and post-surgical care approaches for implanting endoprostheses in a rabbit model of hindlimb amputation. We iteratively designed, fabricated, and implanted unjointed endoprosthesis prototypes in six New Zealand White rabbits following amputation. In the first three rabbits, the skin failed to heal due to dehiscence along the sutured incision. The skin of the final three subsequent rabbits successfully healed over the endoprotheses. Factors that contributed to successful outcomes included modifying the surgical incision to preserve vasculature; increasing the radii size on the endoprostheses to reduce skin stress; collecting radiographs pre-surgery to match the bone pin size to the medullary canal size; and ensuring post-operative bandage integrity. These results will support future work to test jointed endoprostheses that can be attached to muscles.

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Autologous meniscus fragments embedded in atelocollagen gel enhance meniscus repair in a rabbit model

Bone and Joint Research ◽

10.1302/2046-3758.104.bjr-2019-0359.r2 ◽

2021 ◽

Vol 10 (4) ◽

pp. 269-276

Author(s):

Norimasa Matsubara ◽

Tomoyuki Nakasa ◽

Masakazu Ishikawa ◽

Takayuki Tamura ◽

Nobuo Adachi

Keyword(s):

Cell Migration ◽

Therapeutic Potential ◽

Rabbit Model ◽

Histological Evaluation ◽

Effective Strategies ◽

Meniscus Regeneration ◽

Meniscus Cells ◽

Cell Migration And Proliferation

Aims Meniscal injuries are common and often induce knee pain requiring surgical intervention. To develop effective strategies for meniscus regeneration, we hypothesized that a minced meniscus embedded in an atelocollagen gel, a firm gel-like material, may enhance meniscus regeneration through cell migration and proliferation in the gel. Hence, the objective of this study was to investigate cell migration and proliferation in atelocollagen gels seeded with autologous meniscus fragments in vitro and examine the therapeutic potential of this combination in an in vivo rabbit model of massive meniscus defect. Methods A total of 34 Japanese white rabbits (divided into defect and atelocollagen groups) were used to produce the massive meniscus defect model through a medial patellar approach. Cell migration and proliferation were evaluated using immunohistochemistry. Furthermore, histological evaluation of the sections was performed, and a modified Pauli’s scoring system was used for the quantitative evaluation of the regenerated meniscus. Results In vitro immunohistochemistry revealed that the meniscus cells migrated from the minced meniscus and proliferated in the gel. Furthermore, histological analysis suggested that the minced meniscus embedded in the atelocollagen gel produced tissue resembling the native meniscus in vivo. The minced meniscus group also had a higher Pauli’s score compared to the defect and atelocollagen groups. Conclusion Our data show that cells in minced meniscus can proliferate, and that implantation of the minced meniscus within atelocollagen induces meniscus regeneration, thus suggesting a novel therapeutic alternative for meniscus tears. Cite this article: Bone Joint Res 2021;10(4):269–276.

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Acyl-Enzymes as Thrombolytic Agents in a Rabbit Model of Venous Thrombosis

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657183 ◽

1982 ◽

Vol 47 (03) ◽

pp. 269-274 ◽

Cited By ~ 32

Author(s):

R A G Smith ◽

R J Dupe ◽

P D English ◽

J Green

Keyword(s):

Venous Thrombosis ◽

Active Site ◽

Fibrinolytic Activity ◽

Rabbit Model ◽

Fibrinolytic Agent ◽

Essential Nature ◽

Thrombolytic Agents

SummaryA derivative of human lys-plasmin in which the active site has been reversibly acylated (BRL 26920; p-anisoyl human lys-plasmin) has been examined as a fibrinolytic agent in a previously described rabbit model of venous thrombosis and shown to be significantly more active and less fibrinogenolytic than free plasmin. A p-anisoylated derivative of a streptokinase (SK)-activated plasmin preparation was significantly less fibrinogenolytic in vivo than the non-acylated enzyme. Acylation increased the fibrinolytic activity of preparations of SK-plasmin activator complexes. BRL 26921, the active site anisoylated derivative of the primary 2-chain SK-plasminogen complex was the most potent fibrinolytic agent studied. SK-Val442-plasminogen complexes, free or acylated, were biologically inactive in this model and confirm the essential nature of fibrin binding processes for effective thrombolysis in vivo.

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