Mature Bone Tissue Research Articles

Three-dimensional environment and vascularization induce osteogenic maturation of human adipose-derived stem cells comparable to that of bone-derived progenitors.

While human adipose‐derived stem cells (hADSCs) are known to possess osteogenic differentiation potential, the bone tissues formed are generally considered rudimentary and immature compared with those made by bone‐derived precursor cells such as human bone marrow‐derived mesenchymal stem cells (hBMSCs) and less commonly studied human calvarium osteoprogenitor cells (hOPs). Traditional differentiation protocols have tended to focus on osteoinduction of hADSCs through the addition of osteogenic differentiation media or use of stimulatory bioactive scaffolds which have not resulted in mature bone formation. Here, we tested the hypothesis that by reproducing the physical as well as biochemical bone microenvironment through the use of three‐dimensional (3D) culture and vascularization we could enhance osteogenic maturation in hADSCs. In addition to biomolecular characterization, we performed structural analysis through extracellular collagen alignment and mineral density in our bone tissue engineered samples to evaluate osteogenic maturation. We further compared bone formed by hADSCs, hBMSCs, and hOPs against mature human pediatric calvarial bone, yet not extensively investigated. Although bone generated by all three cell types was still less mature than native pediatric bone, a fibrin‐based 3D microenvironment together with vascularization boosted osteogenic maturation of hADSC making it similar to that of bone‐derived osteoprogenitors. This demonstrates the important role of vascularization and 3D culture in driving osteogenic maturation of cells easily available but constitutively less committed to this lineage and suggests a crucial avenue for recreating the bone microenvironment for tissue engineering of mature craniofacial bone tissues from pediatric hADSCs, as well as hBMSCs and hOPs.

Influence of physical activity on linear growth in children and adolescents

Linear growth is the result of bone elongation in children and adolescents mediated by processes of endochondral ossification and maturation of bone tissue. Physical activity (PA) importantly influences both processes through systemic and local effects, mediated by growth hormone, insulin-like factor I, sex hormones, thyroid hormones, glucocorticoid hormones and various cytokines with endo-, para- and autocrine function, secreted by adipose tissue (adipokines) or muscles (myokines). It is important to promote a physically active lifestyle already in early childhood as it tends to persist into adulthood together with favorable body composition. From the safety point-of-view, recent data suggests that PA does not negatively influence linear growth regardless of its duration or intensity, as long as chronic negative energy balance is prevented by sufficient energy intake. The aim of this review is to describe current scientific knowledge on the mechanisms by which PA could influence linear growth and present recent studies analyzing its possible effects.

The efficacy of porous hydroxyapatite chips as gap filling in open-wedge high tibial osteotomy in terms of clinical, radiological, and histological criteria

PurposeHydroxyapatite (HA) does not fully degrade, which raises concerns about poor remodeling and incorporation into the bone after open-wedge high tibial osteotomy (HTO). The purpose of this study was to compare the results between gap filling with allogenous chip bone and HA chip after open-wedge HTO using propensity score matching and to analyze the radiological unabsorbed area of opening gaps histologically in HA using patients. MethodsThe matched variables were age, body mass index, sex, correction angle, and smoking status. After matching, the allogenous group and HA group included 33 patients each with two years of follow-up. The range of motion (ROM), International Knee Documentation Committee (IKDC) subjective score, Knee Injury and Osteoarthritis Outcome Score (KOOS), mechanical axis (MA), tibial slope, osteoconductivity, and absorbability were evaluated and compared between both groups. Among the HA group, 20 patients underwent bone biopsy and histologically analyzed of the radiological unabsorbed area. ResultsThe postoperative ROM, IKDC subjective score, and KOOS were similar in both groups. The osteoconductivities did not differ significantly. The absorbability in the HA group was significantly lower than allogenous group (59.6% vs. 22.6%, P < .001). The histological sections of the radiological unabsorbed area showed mature lamelliform bone tissues were significantly greater than structurally degraded remnant HA (30.4% and 4.2%, P < .001). ConclusionThe HA chips showed an inferior absorbability, however, a mature lamelliform bone was observed in significantly larger amounts than remnant HA in the radiological unabsorbed area. The allogenous bone chips and HA chips showed similar clinical and radiological results after open-wedge HTO.

Mammary Osteosarcoma with Neoplastic Emboli in Cerebellum

Background: The mammary neoplasms are highly frequent in female dogs. It is characterized by the proliferation of epithelial or mesenchymal cells. The mammary osteosarcoma is a example of the proliferation of the last group and its main feature is production of osteoid matrix production and areas of mature bone tissue formation. Metastases to the lungs and regional lymph nodes are frequent, however some other metastasis sites have been reported. The aim of this study is to report a mammary osteosarcoma in a mixed-breed female dog of 12 years old with multiple metastases and neoplastic emboli to the central nervous system.Case: The animal was brought to the Veterinary Hospital of the Uberlândia Federal University (HV/UFU) with the complaint of increase in the volume of the mammary glands. The cytopathological exams was performed in the mass that measured 15 cm of diameter and covering a large region of the mammary gland, from the right cranial thoracic to the right cranial abdominal mammary gland. The cytological diagnostic was inconclusive because of the lack of material for diagnosis. Therefore, total unilateral mastectomy was performed for histopathology analysis. The material was then sent to the Animal Pathology Laboratory of the HV/UFU where routine processing was performed. The microscopy showed proliferation of mesenchymal cells arranged in bundles with intense pleomorfism and producing osteoid matrix, leading to the diagnosis of mammary osteosarcoma. Around 15 days after the diagnostic the animal died and was sent the Animal Pathology Laboratory of the HV/UFU for necropsy. During the external exam there was a mass at the same site of the primary mass previously extracted. Besides it, there were masses affecting lungs, intestine and kidneys. The histopathological exam showed sites of metastasis of osteosarcoma in the organs described, as well as neoplastic emboli in the cerebellum, fortifying the metastatic potential of this neoplasm. Discussion: Mammary osteosarcomas are classified mainly based on the appearance of osteoid matrix produced by osteoblast-like cells or presence of mature bone formation. In the mammary gland it is important to highlight that the neoplasia should not show tubular epithelial cells proliferation, otherwise a better classification of the disease would be carcinosarcoma. The origin of the osteoid cells in this neoplasia is still in discussion. Some authors believe that, like in other regions as thyroid gland, the osseous metaplasia in this region can lead to malignant differentiation of the metaplastic tissue originating the osteosarcoma. The gross appearance, age and breed of the animal are frequently associated with this neoplasia, and it is in agreement of other cases reported previously by different authors. Although metastases are common in this neoplasia, the involvement of the central nervous system is rare and the reports of this condition are usually associated to osteosarcoma of the appendicular skeleton origin. Even though the dog did not show any neurological clinical sign or macroscopic lesion in the central nervous system, this report highlights the importance of complementing these exams with histopathology. In this case we show a microscopic finding made only with an accurate exam of serial transversal cuts of the brain. In conclusion, more descriptive studies of mammary osteosarcoma must be made to a better interpretation of this neoplasm behavior.

A Very Rare Benign Giant Osteoma in Tempero-parieto-occipital Region

Osteoma is a slow growing benign mesenchymalosteoblastic tumor formed by maturebone tissue. The most common site reported is the fronto-ethmoidal region andneighboring sinuses.Involvement of the temporal and occipital squama is extremelyrare. Like giant osteomas in other locations of the skull, they can reach large volumesbut are essentially benign and potentially curable by excision.The author present acase of giant osteoma in Temporo-Parieto-Occipital region in a teenage girl. Bang. J Neurosurgery 2020; 9(2): 173-177

Mg-P/c-SWCNT Bone Cement: The Effect of Filler on Setting Behavior, Compressive Strength and Biocompatibility

Improving the strength of bone cement is one of the critical goals in cement designing to maintain their integrity and stabilize connection between the cement and their surrounding tissue during the time that the cement has been replaced by matured bone tissue. To this aim, the authors decided to evaluate setting behavior and compressive strength of Magnesium Phosphate Cement (MPC) by adding car-boxylated Single-Walled Carbon Nanotubes (c-SWCNTs) and assess the biocompatibility of the composite cement. MPC containing 0 wt% to 0.5 wt% of c-SWCNTs at the Powder to Liquid Ratio (PLR) of 1 g-mL-1 to 2 g-mL-1 were produced. Adding c-SWCNTs to MPC postponed the setting time of the cement at the beginning of the cementation process and preserved the reaction with a high rate for a longer time. In addition, the compressive strength of MPC was enhanced to 28 MPa by adding 0.2 wt% c-SWCNTs because of producing cement with compact and uniform micro structure. In addition, cell behavior on MPC with/without c-SWCNTs indicated no cytotoxic effect alongside a suitable adhesion and proliferation of them.

ЭКСПЕРИМЕНТАЛЬНОЕ ИЗУЧЕНИЕ ИНТЕГРАЦИОННЫХ ОСОБЕННОСТЕЙ ПОРИСТО-ПРОНИЦАЕМОГО И СЕТЧАТОГО НИКЕЛИДА ТИТАНА IN VIVO

Objective: Morphological assessment of the integration features of the combined use of porous permeable and textile mesh titanium nickelide with bone structures of the recipient zone. Methods: The study was carried out on 20 Chinchilla rabbits of both sexes at the age of 1-1.5 years with a bodyweight of 2500-4000 g. In animals, the artificial defect was created in one of the areas of the lower jaw, where a porous permeable titanium nickelide was installed, wrapped in a textile mesh version of it was installed. Animals were removed from the experiment for 30, 90, 180, and 360 days of research via intraperitoneal injection of mortal dose 1% solution thiopental sodium. The material for histological research was fixed in 10% buffered formalin during 12 hours after then washed with water and decalcified. The prepared sections were stained with hematoxylin-eosin. Microscopic examination of the stained preparations and photography were carried out using a light microscope Axioscope 40 (Zeiss, Germany) via a digital camera (Canon, Japan). Results: Studies have shown that with the combined use of porous permeable and textile mesh titanium nickelide, the artificially created defects of the mandibula between both contacting surfaces are formed directly, which leads to stable fixing. The porous structure of the material, its hysteresis behavior with organism tissues, provides widespread regeneration of cells and formed a homogeneous mature bone tissue bone tissue, both in the pores and around the structure. Conclusions: These and other facts indicate the high integration properties of the material that is investigated, which ensures optimal growth and population of osteogenic cells in the vicinity of defective bone areas in a growing organism. Keywords: Bone defect, osteointegration, regeneration, titanium nickelide, porous permeable implant.

Эффективность экстрактов &lt;i&gt;Saussurea controversa&lt;/i&gt; и &lt;i&gt;Fillipendula ulmaria&lt;/i&gt; на фоне антибиотикотерапии остеомиелита в эксперименте

Курсовое применение экстрактов Saussurea controversa DC (S.c.) и Fillipendula ulmaria (L). Maxim. (F.u.), содержащих широкий набор флавонолгликозидов, при экспериментальном остеомиелите приводит к стимуляции гранулопоэза в 2,8 и 2,2 раза соответственно (p = 0,04) и регенерации костной ткани (плотность распределения остеобластов возрастает в 5 раз, p = 0,02) в зоне поражения у крыс. В результате исследования миелограмм костного мозга отмечены активация митотической активности гранулоцитов, увеличение количества миелобластов в 5,6 и 4,2 раза (p = 0,02) и зрелых форм гранулоцитов (в 2,5 и 1,5 раза, p = 0,04), измененных в результате антибиотикотерапии. После применения экстракта S.c. в костном мозге крыс с остеомиелитом возрастает общее количество ядросодержащих клеток в 2,7 (p = 0,04) раза. Улучшение морфологической картины костной ткани (активация клеток эндоста, периоста, появление остеобластических «почек», формирование грануляционной ткани) и формирование зрелой костной ткани более выражено (на 12 %, p = 0,02) при применении экстракта S.c., по сравнению с экстрактом F.u.

LIP OSTEOLIPOMA, CLINICAL AND SURGICAL MANAGEMENT OF AN INFREQUENT DISEASE

Lipomas are relatively infrequent mesenchymal benign neoplasms of oral soft tissues. A wide range of subtypes of lipomas have been previously described, including fibrolipoma, angiolipoma, pleomorphic lipoma, and osteolipoma. The aim of this study is to present a clinical case of an 83-year-old man with a painless labial mass of 20-year duration with a remarkable increase in the size of the lesion in the last 2 years. Oral examination revealed a yellowish and sessile mass located in the lower labial mucosa. The provisional diagnosis was a lipoma, but during its surgical excision, a cartilaginouslike tissue was noticed generating some doubts about our previous diagnosis. The histopathologic findings revealed mature adipocytes surrounding bone tissue and the final diagnosis was osteolipoma. The presence of bony calcifications within this tumor could be related to metaplastic changes during the evolution of the lesion. This rare presentation was previously reported with different oral locations.

Biomechanical assessment of the stability of osteochondral grafts implanted in porcine and bovine femoral condyles.

Osteochondral grafts are used clinically to repair cartilage and bone defects and to restore the congruent articulating surfaces of the knee joint following cartilage damage or injury. The clinical success of such osteochondral grafts is heavily reliant on the biomechanical and tribological properties of the surgical repair; however, a limited number of studies have investigated these factors. The aim of this study was to evaluate the influence of graft harvesting and implantation technique as well as bone properties on the primary stability of press-fit implanted osteochondral grafts using a series of uniaxial experimental push-in and push-out tests. Animal (porcine and bovine) knees were used to deliver models of different bone properties (elastic modulus and yield stress). The study showed the graft harvesting method using either a chisel or drill-aided trephine to have no influence on primary graft stability; however, the preparation technique for the graft recipient site was shown to influence the force required to push the graft into the host tissue. For example, when the length of the graft was equal to the recipient site (bottomed), the graft was more stable and dilation of the recipient site was shown to reduce short-term graft stability especially in immature or less dense bone tissue. The push-out tests which compared tissue of different skeletal maturities demonstrated that the maturity of both the graft and host bone tissue to influence the stability of the graft. A higher force was required to push out more skeletally mature grafts from mature bone tissue. The study demonstrates the importance of surgical technique and bone quality/properties on the primary stability and ultimately, the success of osteochondral grafts in the knee.

Changes with age (from 0 to 37 D) in tibiae bone mineralization, chemical composition and structural organization in broiler chickens

ABSTRACTBroiler chickens have an extreme physiology (rapid growth rates) that challenges the correct bone mineralization, being an interesting animal model for studying the development of bone pathologies. This work studies in detail how the mineralization, chemistry, and structural organization of tibiae bone in broiler chickens change with age during the first 5 wk (37 D) from hatching until acquiring the final weight for slaughter. During the early growth phase (first 2 wk), the rapid addition of bone tissue does not allow for bone organic matrix to fully mineralize and mature, and seems to be a critical period for bone development at which bone mineralization cannot keep pace with the rapid growth of bones. The low degree of bone mineralization and large porosity of cortical bone at this period might be responsible of leg deformation and/or other skeletal abnormalities commonly observed in these birds. Later, cortical bone porosity gradually decreases and the cortical bone became fully mineralized (65%) at 37 D of age. At the same time, bone mineral acquires the composition of mature bone tissue (decreased amount of carbonate, higher crystallinity, Ca/P = 1.68). However, the mineral part was still poorly organized even at 37 D. The oriented fraction was about 0.45 which means that more than half of apatite crystals within the mineral are randomly oriented. Mineral organization (crystal orientation) had an important contribution to bone-breaking strength. Nevertheless, locally determined (at tibia mid-shaft) bone properties (i.e., cortical thickness, crystal orientation) has only a moderate correlation (R2 = 0.33) with bone breaking strength probably due to large and highly heterogeneous porosity of bone that acts as structural defects. On the other hand, the total amount of mineral (a global property) measured by total ash content was the best predictor for breaking strength (R2 = 0.49). Knowledge acquired in this study could help in designing strategies to improve bone quality and reduce the incidence of skeletal problems in broiler chickens that have important welfare and economic implications.

The period circadian clock 2 gene responds to glucocorticoids and regulates osteogenic capacity.

IntroductionThe central regulatory system that generates biological rhythms is regulated by circadian clock genes expressed by cells in the suprachiasmatic nucleus. Signals from this system are converted to adrenocortical hormones through the sympathetic nervous system and transmitted to peripheral organs. Another system releases glucocorticoids (GCs) in response to stress through the HPA-axis. Here we investigated the second messenger GC, which is shared by these systems and influences the expression of circadian clock genes of cells of the musculoskeletal system and in viable bone tissue.MethodsWe used mouse-derived cell lines, which differentiate into osteoblasts (MC3T3-E1, C2C12, and 10T1/2) as well as primary cultures of mouse osteoblasts to determine the expression levels of circadian clock genes that respond to GC. Mice (mPer2m/m) with an inactivating mutation in the period circadian clock 2 gene (Per2) exhibit marked dysrhythmia. Here we compared the bone morphologies of mPer2m/m mice with those of wild-type (WT) mice.ResultsThe expression of major circadian clock genes was detected in each cell line, and their responsiveness to GC was confirmed. We focused on Per2, a negative regulator of the circadian clock and found that a Per2-loss-of-function mutation increased the proliferative capacity of osteoblasts. Treatment of mutant mice with slow-release GC and bisphosphonate affected the maturation of bone tissue, which reflects a tendency to retard calcification.ConclusionOur investigations of the mechanisms that regulate circadian rhythm function in tissues of the musculoskeletal system that respond to the stress hormone GC, reveal that Per2 is required for the maturation of bone tissue. Thus, the influences of the systems that control circadian rhythms and the responses to stress by regenerating tissue used for regenerative medicine must be considered and studied in greater detail.

Lingual Osseous Choristoma: A Case Report and Review of the Literature

Introductıon: Osseous choristoma is a benign lesion that is characterized by proliferation of mature osseous tissue in an abnormal anatomical location. The lesion, which was first described by Monserrat in 1913 as “lingual osteoma” has been called “osseous choristoma” since 1971. Here, we present a rare case of osseous choristoma located on the tongue and a review of the literature.Case Report: A 26 year-old male patient was referred to the Department of ENT with the complaint of swelling of the tongue. Physical examination showed a nodular, sessile lesion on the base of the tongue and the lesion was removed. Histopathological examination of the material revealed a well-defined, submucosal lesion consisting of mature bone tissue and was reported as “osseous choristoma”.Conclusıon: Osseous choristoma is a benign lesion that occurs mostly in women in their second or third decades of life, although it can be seen in a wide age range. Osseous choristoma may occur in different locations of the oral cavity and maxillofacial region such as the tongue, buccal mucosa, alveolar mucosa, submandibular region, submental region, masseter muscle and palate. This rare entity should be kept in mind because it may be confused with other benign lesions of the tongue like hemangioma, lymphangioma, hamartoma and malignant tumors.

A Cyst Close to the Heart

A 49-year-old Lebanese man presented to the hospital with right-sided pleuritic chest pain without associated respiratory or systemic symptoms. His vitals on presentation were stable, and examination was unremarkable. He had mild leukocytosis with 9.8% eosinophils. Imaging including cardiac magnetic resonance imaging with and without contrast revealed an extra pericardial, multiloculated anterior mediastinal cyst (Figure 1). A diagnosis of hydatid cyst was suspected based on epidemiologic history and radiologic appearance. Echinococcus serology was found to be positive. Patient was started on empiric anthelminthic treatment followed by surgical excision. Intraoperatively, the wall of the excised cyst showed calcification and sebaceous contents (Figure 2). Histopathologic exam showed multilocular cyst lined by squamous epithelial cells and foci of mature bone tissue (Figure 3), pancreatic acini, and ciliated columnar epithelial ducts consistent with a diagnosis of benign mature cystic teratoma. No parasite was seen. Anthelminthic therapy was discontinued, and the patient reported to be doing well on the follow-up visit. Similar cases have been reported in the past.1Patel I.J. Hsiao E. Ahmad A.H. Schroeder C. Gilkeson R.C. AIRP Best Cases in radiologic-pathologic correlation: mediastinal mature cystic teratoma.RadioGraphics. 2013; 33: 797-801Crossref PubMed Scopus (19) Google Scholar, 2Jaakik B. Benjelloun H. A Rare pericardial cyst resembling hydatid cyst on echocardiography.Intern Med. 2010; 49: 1673-1674Google Scholar, 3Montebello A. Mizzi A. Cassar P.J. Cassar K. Benign cystic mediastinal teratoma presenting as a massive pleural effusion in a 17-year–old boy.BMJ Case Reports. 2017; 2017 (bcr2016217439)Google ScholarFigure 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)Figure 3View Large Image Figure ViewerDownload Hi-res image Download (PPT) The authors wish to acknowledge Dr Khushi Nagori, MBBS, Department of Pathology, Ascension St John Hospital, Detroit, Michigan.

Angiogenesis and new bone formation in novel unidirectional porous beta-tricalcium phosphate: a histological study.

Affinos® (Kuraray Co., Ltd., Tokyo, Japan) is a beta-tricalcium phosphate (TCP) artificial bone comprising a novel unidirectional porous structure with 57% porosity. This study examined angiogenesis and bone formation over time with unidirectional porous beta-TCP (UDPTCP). Ten Japanese White rabbits were used in this study. A 5 × 8-mm rectangular area of periosteum was resected, followed by preparation of a cortical bone defect using a high-speed bur. UDPTCP was embedded in the defect in the direction of the pores, parallel to the axis of the tibia. Tissue samples were harvested at 2weeks (n = 3) and 6weeks (n = 7) after implantation. Just before euthanasia, the vasculature of the lower limb was perfused with saline from the femoral artery and filled with MICROFIL® (Flow Tech, Inc., Carver, MA) to create a vascular cast. The tibia was cut longitudinally at the center of the material. Decalcified sagittal sections treated with hematoxylin and eosin staining, undecalcified sagittal sections treated with Villanueva-Goldner staining, and axial unstained sections were used for histological evaluation. The lengths of the largest vessels and newly formed bone at the material border were measured in a sagittal section. Both lengths were significantly larger at 6weeks than at 2weeks. In the axial sections at 2weeks, newly formed vessels filled with blue dye grew along the pores of the UDPTCP. Mature bone tissue with a lamellar structure was observed at 6weeks. Our histological findings demonstrated that angiogenesis and bone formation occur over time in UDPTCP.

Atraumatic laparoscopic intraperitoneal mesh fixation using a new laparoscopic device: an animal experimental study.

Laparoscopic ventral and incisional hernia repair (LVIHR) has become a common procedure because of its feasibility and safety, but it is not free of complications. Acute and chronic post-operative pain and bleeding caused by traumatic fixation of the mesh are frequently prolonging the hospital stay. The aim of this study was to analyze the behavior of n-butyl-cyanoacrylate (GLUBRAN® 2) as only mesh fixation METHODS: Ten female pigs were involved in the study and were divided into two groups of five (A and B). Animals in each group underwent a laparoscopic procedure in which two meshes were placed intraperitoneally and fixed with the same synthetic glue only. Animals in group A were sacrificed after 3weeks, and those in group B were sacrificed after 12weeks. We studied the morphological, biomechanical, and histological characteristics of the intraperitoneal mesh-tissue interface RESULTS: No disruption, migration or folding was observed in any of the pigs. In group A, the mean tensile strength was 1.4N/cm (± 0.2) while in group B, the mean tensile strength was 2.5N/cm (± 0.8). Histological analyses, in areas where mesh was fixed using the glue, showed a chronic lymphocytic inflammatory reaction with a granulomatous component and a marked desmoplastic reaction made up of immature collagen and numerous fibroblasts acquiring myofibroblastic characteristics. In some areas corresponding to fixation, the desmoplastic reaction originated from mature lamellar bone tissue with osteocytes and osteoblasts. Laparoscopic mesh fixation with only the synthetic comonomer glue GLUBRAN® 2 is feasible, effective, and safe in intraperitoneal incisional/ventral hernia repair in this animal model.

A Very Rare Benign Giant Osteoma in Tempero-Parieto-Occipital Region

Osteoma is a slow growing benign mesenchymal osteoblastic tumor formed by mature bone tissue. The most common site reported is the fronto-ethmoidal region and neighboring sinuses. Involvement of the temporal and occipital squama is extremely rare. Like giant osteomas in other locations of the skull, they can reach large volumes but are essentially benign and potentially curable by excision. The author presents a case of giant osteoma in Temporo-Parieto-Occipital region in a teenage girl.

Bone Regeneration in the Application of a New Device for Osteosynthesis in the Experiment

Background. Treatment of residual cavities after radical surgery for bone diseases is a vital problem of modern traumatology. Currently, there is an active search for devices both for osteosynthesis and bone-substituting masses. Aims. The purpose of this work was to test a new device for osteosynthesis. It can be used both for fixing bone fragments, and for studying the morphological features of bone regenerate in experiment.Materials and methods. A device for bone osteosynthesis of tubular bones in an experiment (Patent of the Russian Federation N 20116121487) was applied. The device consisted of two half-bushings, fastened to each other by a fierce clamp. Polypropylene was used as the material for the half-bushings, therefore no immunological reactions were observed. On the inner surface there were silicone cylinders, which directed pressure on the fragments and did not disturb the nutrition of the periosteum. The experiment was performed on Wistar rats. The surgical defect of the femur was filled with hydroxyapatite. Two groups of animals were identified. The bone in the first group was fixed by the device. The wire cerclage was used in the second group.Results. The study showed that the developed device does not disturb the nutrition of the periosteum, and also tightly fixes the osteoplastic material in the bone defect. Histological examination showed that bone regeneration was faster when the device was used. On the 21st day of the experiment, the regenerate filled the defect in the control group by 62 %, and in the experimental group by 73 %. The regenerate was represented by a woven bone. In all animals, bone regenerate formed a strong osteo-integrative connection with the maternal bone. In both groups, it looked like a mature bone tissue at the end of the experiment (28 days).Conclusion. The data indicate that the device does not disturb the processes of bone formation and allows for more efficient use osteoplastic material.

Bone Tissue Engineering in a Perfusion Bioreactor Using Dexamethasone-Loaded Peptide Hydrogel.

The main goal of this study was the formation of bone tissue using dexamethasone (DEX)-loaded [COCH3]-RADARADARADARADA-[CONH2] (RADA 16-I) scaffold that has the ability to release optimal DEX concentration under perfusion force. Bone-marrow samples were collected from three patients during a hip arthroplasty. Human mesenchymal stem cells (hMSCs) were isolated and propagated in vitro in order to be seeded on scaffolds made of DEX-loaded RADA 16-I hydrogel in a perfusion bioreactor. DEX concentrations were as follows: 4 × 10−3, 4 × 10−4 and 4 × 10−5 M. After 21 days in a perfusion bioreactor, tissue was analyzed by scanning electron microscopy (SEM) and histology. Markers of osteogenic differentiation were quantified by real-time polymerase chain reaction (RT-PCR) and immunocytochemistry. Minerals were quantified and detected by the von Kossa method. In addition, DEX release from the scaffold in a perfusion bioreactor was assessed. The osteoblast differentiation was confirmed by the expression analysis of osteoblast-related genes (alkaline phosphatase (ALP), collagen I (COL1A1) and osteocalcin (OC). The hematoxylin/eosin staining confirmed the presence of cells and connective tissue, while SEM revealed morphological characteristics of cells, extracellular matrix and minerals—three main components of mature bone tissue. Immunocytochemical detection of collagen I is in concordance with given results, supporting the conclusion that scaffold with DEX concentration of 4 × 10−4 M has the optimal engineered tissue morphology. The best-engineered bone tissue is produced on scaffold loaded with 4 × 10−4 M DEX with a perfusion rate of 0.1 mL/min for 21 days. Differentiation of hMSCs on DEX-loaded RADA 16-I scaffold under perfusion force has a high potential for application in regenerative orthopedics.

Hypertrophic Osteopathy in a Cat

Background: Hypertrophic osteopathy (OH) is a syndrome characterized by progressive bilateral periosteal bone neoformation that mainly affects the thoracic and pelvic limb bones’ metaphyses and diaphyses. In most cases, it is secondary to a chronic primary lesion located in the thoracic cavity but can be associated with an abdominal injury that has already been occurred. The occurrence of this condition without being associated with a primary lesion is considered infrequent in animals. The purpose of this report was to describe a case of idiopathic hypertrophic osteopathy in a cat with a description of clinical signs and radiographic and anatomopathological findings.Case: A male adult cat was brought to the veterinarian with an initial observation by the owner of four limbs’ volume increase, apathy, and reluctance to move. Upon clinical examination, the animal presented dehydration, mucosal hyperemia, hyperthermia, and bilateral edema of the thoracic and pelvic limbs. Based on the radiographic examination, a periosteal reaction with palisade-like appearance was found in the metacarpals, radios, ulna, humerus, scapulae, tibias, and fibulae. There were no significant changes in additional exams. Due to poor prognosis, the cat was euthanized and referred for necropsy and histopathological examination. All organs were examined both macroscopically and microscopically. Fragments were fixed in 10% formalin and routinely processed for histological slides with hematoxylin–eosin and Masson's trichrome, and limb bones that were not fixed in formalin were macerated. Lesions were observed only in the thoracic and pelvic limbs. Macroscopically, there was a diffuse, regular, slightly firm volume increase, covered by abundant gelatinous whitish tissue. The periosteal bone neoformations were characterized by numerous papillary projections distributed throughout the phalanges, radius, ulna, humerus, scapula, tibia and fibula. Histologically, the original bone matrix was surrounded by lightly organized eosinophilic material in bundles. Young bone matrix-formed trabeculae perpendicular to the original bone matrix, projecting into the mature bone tissue, was attached to the cortical layer.Discussion: The hypertrophic osteopathy diagnosis was based on clinical signs, radiographic examinations, and anatomopathological findings. Although the long bones of the pelvic limbs are often the most affected, the lesions were more marked in the thoracic limbs in this cat. The presumptive diagnosis was made through radiographic examination. Radiography is considered a very useful diagnostic method in animals suffering from this condition. Histological changes are compatible with persistent phases of hypertrophic osteopathy resulting from the action of osteoclasts and osteoblasts, with osteoid matrix deposition in the existing cortical bone. Since this cat didn't present macroscopic and microscopic alterations beyond the bone lesions, it was not possible to attribute them to a primary cause. For this reason, osteopathy was considered idiopathic in this case. We concluded that lesions of hypertrophic osteopathy may be more pronounced in the thoracic limbs. In cases of animals with signs of limb volume increase even in the absence of thoracic and abdominal lesions, hypertrophic osteopathy should be included as a differential diagnosis. The radiographic and anatomopathological examinations are enough to diagnose this condition.