Extrinsic and intrinsic blood supply to the optic chiasm.

Although there have been many studies of the arterial cerebral blood supply, only seven have described the optic chiasm (OC) blood supply and their results are contradictory. The aim of this study was to analyze the extrinsic and intrinsic OC blood supply on cadaveric specimens using dissections and microcomputer tomography (Micro-CT). Thirteen human specimens were dissected and the internal or common carotid arteries were injected with red latex, China Ink with gelatin or barium sulfate. Three Micro-CTs were obtained to reveal the intrinsic blood supply to the OC. The superior hypophyseal arteries (SupHypA) (13/13) and posterior communicating artery (PCoA) (12/13) supplied the pial network on the inferior side of the OC. The first segment of the anterior cerebral artery (ACA) (10/10), SupHypA (7/10), the anterior communicating artery (ACoA) (9/10), and PComA (1/10) supplied the pial network of its superior side. The intrinsic OC blood supply was divided into three networks (two lateral and one central). Capillaries entering the OC originated principally from the inferior pial network. The lateral network capillaries had the same orientation as the visual lateral pathways, but the central network was not correlated with the nasal fibers crossing into the OC. There was no anastomosis in the pial or intrinsic networks. Only SupHypA, PCoA, ACoA, and ACA were involved in the OC blood supply. Because there was no extrinsic or intrinsic anastomosis, all arteries should be preserved. Tumor compression of the inferior intrinsic arterial network could contribute to visual defects. Clin. Anat. 31:432-440, 2018. © 2017 Wiley Periodicals, Inc.

Interleukin-33 and RANK-L Interplay in the Alveolar Bone Loss Associated to Periodontitis.

INTRODUCTION: Chronic Periodontitis (CP) is an inflammatory disease of bacterial origin that results in alveolar bone destruction. Porphyromonas gingivalis (Pg), one of the main periopathogens, initiates an inflammatory cascade by host immune cells thereby increasing recruitment and activity of osteoclasts, the bone resorbing cells, through enhanced production of the crucial osteoclastogenic factor, RANK-L. Antibodies directed against some cytokines (IL-1ß, IL-6 and TNF-α) failed to exhibit convincing therapeutic effect in CP. It has been suggested that IL-33, could be of interest in CP. OBJECTIVE: the present study aims to analyze whether and how IL-33 and RANK-L and/or their interplay are involved in the bone destruction associated to CP. MATERIAL AND METHODS: mRNAs and protein expressions of IL-33 and RANK-L were analyzed in healthy and CP human gingival samples by immunohistochemistry (IHC) and RT-qPCR. Murine experimental periodontitis (EP) was induced using Pg infected ligature and Pg free ligature around the first maxillary molar. Alveolar bone loss was recorded by µCT. Mouse gingival explants were stimulated for 24 hours with IL-33 and RANK-L mRNA expression investigated by RT-qPCR. Human oral epithelial cells were infected by Pg for 6, 12; 24 hours and IL-33 and RANK-L mRNA expressions were analyzed by RT-qPCR. RESULTS: IL-33 is overexpressed in gingival epithelial cells in human affected by CP as in the murine EP. In human as in murine gingival cells, RANK-L was independently induced by Pg and IL-33. We also showed that the Pg-dependent RANK-L expression in gingival epithelial cells occured earlier than that of IL-33. CONCLUSION: Our results evidence that IL-33 overexpression in gingival epithelial cells is associated with CP and may trigger RANK-L expression in addition to a direct effect of Pg. Finally, IL-33 may act as an extracellular alarmin (danger signal) showing proinflammatory properties in CP perpetuating bone resorption induced by Pg infection.

Sequential Proximal Optimizing Technique in Provisional Bifurcation Stenting With Everolimus-Eluting Bioresorbable Vascular Scaffold: Fractal Coronary Bifurcation Bench for Comparative Test Between Absorb and XIENCE Xpedition.

OBJECTIVES: The aim of this fractal bifurcation bench study was to compare provisional bifurcation stenting with a "re-POT" sequence, comprising a proximal optimizing technique (POT), side branch inflation, and final POT, between a bioresorbable vascular scaffold (BVS) and a metallic stent. BACKGROUND: Re-POT proved significantly better than kissing balloon inflation in maintaining circular geometry without overstretch in metal stents, while significantly reducing side branch ostium strut obstruction and global strut malapposition. This should be useful for BVSs, which are more easily breakable. METHODS: Twenty left main-like and 20 left anterior descending-like fractal coronary bifurcation bench models used 10 each 2.5 × 24 mm and 3.5 × 24 mm Absorb (Ab) BVSs and 10 each 2.5 × 24 mm and 3.5 × 24 mm XIENCE Xpedition (XX) metal stents, implanted by re-POT, with optical coherence tomographic analysis at each step and micro-computed tomographic analysis of Ab devices to detect strut fracture. RESULTS: With Ab devices, re-POT reduced percentage strut malapposition close to XX rates (0.8 ± 0.7% vs. 0.0 ± 0.0%, p < 0.05; 3.5 ± 1.7% vs. 0.3 ± 0.6%, p < 0.05), conserving proximal circularity (elliptical ratio, 1.04 vs. 1.03 and 1.04 vs. 1.04; p = NS). Mean post-re-POT proximal expansion was 0.6 ± 0.1 mm (+21.6 ± 2.1%) for 2.5-mm and 1.0 ± 0.1 mm (+23.6 ± 2.2%) for 3.5-mm Ab devices, with only 1 strut fracture (left anterior descending-like bench). Side branch ostium strut obstruction was greater with Ab scaffolds than XX stents: 41.1 ± 9.4% versus 16.4 ± 8.1% (p < 0.05) and 31.8 ± 3.2% versus 10.0 ± 5.3% (p < 0.05), respectively, for 2.5- and 3.5-mm scaffolds and stents. Ab scaffolds showed 2 ± 1% moderate but significant late recoil as of 1 h, reaching 4 ± 2% by 24 h (p < 0.05). CONCLUSIONS: Re-POT optimized most Ab provisional bifurcation treatments, without fracture, respecting fractal geometry, and without exceeding 1.0-mm proximal differential diameter.

Functional Langerinhigh-Expressing Langerhans-like Cells Can Arise from CD14highCD16- Human Blood Monocytes in Serum-Free Condition.

Langerhans cells (LCs) are epithelial APCs that sense danger signals and in turn trigger specific immune responses. In steady-state, they participate in the maintenance of peripheral tolerance to self-antigens whereas under inflammation LCs efficiently trigger immune responses in secondary lymphoid organs. It has been demonstrated in mice that LC-deprived epithelia are rapidly replenished by short half-life langerin-expressing monocyte-derived LCs (MDLCs). These surrogate LCs are thought to be progressively replaced by langerin(high) LCs arising from self-renewing epithelial precursors of hematopoietic origin. How LCs arise from blood monocytes is not fully understood. Hence, we sought to characterize key factors that induce differentiation of langerin(high)-expressing monocyte-derived Langerhans-like cells. We identified GM-CSF and TGF-ß1 as key cytokines to generate langerin(high)-expressing cells but only in serum-free conditions. These cells were shown to express the LC-specific TROP-2 and Axl surface markers and contained Birbeck granules. Surprisingly, E-cadherin was not spontaneously expressed by these cells but required a direct contact with keratinocytes to be stably induced. MDLCs induced stronger allogeneic T cell proliferations but released low amounts of inflammatory cytokines upon TLR stimulation compared with donor-paired monocyte-derived dendritic cells. Immature langerin(high) MDLCs were responsive to MIP-3ß/CCL20 and CTAC/CCL27 chemokine stimulations. Finally, we demonstrated that those cells behaved as bona fide LCs when inserted in a three-dimensional rebuilt epithelium by becoming activated upon TLR or UV light stimulations. Collectively, these results prompt us to propose these langerin(high) MDLCs as a relevant model to address LC biology-related questions.

A simple and effective approach to prepare injectable macroporous calcium phosphate cement for bone repair: Syringe-foaming using a viscous hydrophilic polymeric solution.

In this study, we propose a simple and effective strategy to prepare injectable macroporous calcium phosphate cements (CPCs) by syringe-foaming via hydrophilic viscous polymeric solution, such as using silanized-hydroxypropyl methylcellulose (Si-HPMC) as a foaming agent. The Si-HPMC foamed CPCs demonstrate excellent handling properties such as injectability and cohesion. After hardening the foamed CPCs possess hierarchical macropores and their mechanical properties (Young's modulus and compressive strength) are comparable to those of cancellous bone. Moreover, a preliminary in vivo study in the distal femoral sites of rabbits was conducted to evaluate the biofunctionality of this injectable macroporous CPC. The evidence of newly formed bone in the central zone of implantation site indicates the feasibility and effectiveness of this foaming strategy that will have to be optimized by further extensive animal experiments. STATEMENT OF SIGNIFICANCE: A major challenge in the design of biomaterial-based injectable bone substitutes is the development of cohesive, macroporous and self-setting calcium phosphate cement (CPC) that enables rapid cell invasion with adequate initial mechanical properties without the use of complex processing and additives. Thus, we propose a simple and effective strategy to prepare injectable macroporous CPCs through syringe-foaming using a hydrophilic viscous polymeric solution (silanized-hydroxypropyl methylcellulose, Si-HPMC) as a foaming agent, that simultaneously meets all the aforementioned aims. Evidence from our in vivo studies shows the existence of newly formed bone within the implantation site, indicating the feasibility and effectiveness of this foaming strategy, which could be used in various CPC systems using other hydrophilic viscous polymeric solutions.

Pomegranate Peel Extract Prevents Bone Loss in a Preclinical Model of Osteoporosis and Stimulates Osteoblastic Differentiation in Vitro.

The nutritional benefits of pomegranate have attracted great scientific interest. The pomegranate, including the pomegranate peel, has been used worldwide for many years as a fruit with medicinal activity, mostly antioxidant properties. Among chronic diseases, osteoporosis, which is associated with bone remodelling impairment leading to progressive bone loss, could eventually benefit from antioxidant compounds because of the involvement of oxidative stress in the pathogenesis of osteopenia. In this study, with in vivo and ex vivo experiments, we investigated whether the consumption of pomegranate peel extract (PGPE) could limit the process of osteopenia. We demonstrated that in ovariectomized (OVX) C57BL/6J mice, PGPE consumption was able to significantly prevent the decrease in bone mineral density (-31.9%; p < 0.001 vs. OVX mice) and bone microarchitecture impairment. Moreover, the exposure of RAW264.7 cells to serum harvested from mice that had been given a PGPE-enriched diet elicited reduced osteoclast differentiation and bone resorption, as shown by the inhibition of the major osteoclast markers. In addition, PGPE appeared to substantially stimulate osteoblastic MC3T3-E1 alkaline phosphatase (ALP) activity at day 7, mineralization at day 21 and the transcription level of osteogenic markers. PGPE may be effective in preventing the bone loss associated with ovariectomy in mice, and offers a promising alternative for the nutritional management of this disease.

Development of mandibular osteoradionecrosis in rats: Importance of dental extraction.

OBJECTIVES: To develop an animal model of mandibular osteoradionecrosis (ORN) using a high-energy radiation source (as used in human therapeutics) and to assess the role of tooth extraction on ORN development. MATERIALS AND METHODS (STUDY DESIGN): Ten animals were irradiated with a single 35- or 50-Gy dose. Three weeks later, the second left mandibular molar was extracted from three animals in each group. Nine weeks after irradiation, the animals were euthanized, with an injection of contrast agent in the bloodstream to highlight vascularization. Mandibles were harvested and studied using micro-CT, histology, tartrate-resistant acid phosphatase activity and scanning electron microscopy. RESULTS: This study demonstrates that a single 50-Gy dose associated with molar extraction is necessary for ORN development. In these conditions, absence of healing of the mucosa and bone, dental effects, fibrosis, an increase in osteoclast activity and a decrease in vascularization were observed. We also determined that molar extraction increases the impact of the cellular effects of radiation. CONCLUSION: The mandibular ORN animal model was validated after 50-Gy irradiation and molar extraction. The results of this study therefore support an animal ORN model and tissue engineering strategies will now be developed to regenerate bone for patients with head and neck cancer.

Comparative Analysis of Sequential Proximal Optimizing Technique Versus Kissing Balloon Inflation Technique in Provisional Bifurcation Stenting: Fractal Coronary Bifurcation Bench Test.

OBJECTIVES: This study used a fractal bifurcation bench model to compare 6 optimization sequences for coronary bifurcation provisional stenting, including 1 novel sequence without kissing balloon inflation (KBI), comprising initial proximal optimizing technique (POT) + side-branch inflation (SBI) + final POT, called "re-POT." BACKGROUND: In provisional bifurcation stenting, KBI fails to improve the rate of major adverse cardiac events. Proximal geometric deformation increases the rate of in-stent restenosis and target lesion revascularization. METHODS: A bifurcation bench model was used to compare KBI alone, KBI after POT, KBI with asymmetric inflation pressure after POT, and 2 sequences without KBI: initial POT plus SBI, and initial POT plus SBI with final POT (called "re-POT"). For each protocol, 5 stents were tested using 2 different drug-eluting stent designs: that is, a total of 60 tests. RESULTS: Compared with the classic KBI-only sequence and those associating POT with modified KBI, the re-POT sequence gave significantly (p < 0.05) better geometric results: it reduced SB ostium stent-strut obstruction from 23.2 ± 6.0% to 5.6 ± 8.3%, provided perfect proximal stent apposition with almost perfect circularity (ellipticity index reduced from 1.23 ± 0.02 to 1.04 ± 0.01), reduced proximal area overstretch from 24.2 ± 7.6% to 8.0 ± 0.4%, and reduced global strut malapposition from 40 ± 6.2% to 2.6 ± 1.4%. CONCLUSIONS: In comparison with 5 other techniques, the re-POT sequence significantly optimized the final result of provisional coronary bifurcation stenting, maintaining circular geometry while significantly reducing SB ostium strut obstruction and global strut malapposition. These experimental findings confirm that provisional stenting may be optimized more effectively without KBI using re-POT.

Wnt5a is expressed in spondyloarthritis and exerts opposite effects on enthesis and bone in murine organ and cell cultures.

Spondyloarthritis (SpA) is a chronic inflammatory joint disorder that initiates at the enthesis, where tendons attach to bone through a fibrocartilage zone. At late stages, excessive bone apposition appears within the diseased enthesis. Because Wnt5a participates to normal bone formation and appears related to inflammatory processes, we investigated the role of this Wnt growth factor in inflammation-associated ossification in SpA. The concentration of Wnt5a assessed by enzyme-linked immunosorbent assay in synovial fluids of patients with SpA (2.58 ± 0.98 ng/mL) was higher than in osteoarthritic patients (1.33 ± 0.71 ng/mL). In murine primary cultures of tendon cells, chondrocytes, and osteoblasts and in an organotypic model of mouse ankle, we showed that tumor necrosis factor α reversibly diminished Wnt5a expression and secretion, respectively. Wnt5a decreased gene expression of differentiation markers and mineralization in cultured chondrocytes and reduced alkaline phosphatase activity in Achilles tendon enthesis (-14%) and osteocalcin protein levels released by ankle explants (-36%). On the contrary, Wnt5a stimulated ossification markers' expression in cultured osteoblasts and increased the bone volume of the tibial plateau of the cultured explants (+19%). In conclusion, our results suggest that Wnt5a is expressed locally in the joints of patients with SpA. Wnt5a appears more associated with ossification than with inflammation and tends to inhibit mineralization in chondrocytes and enthesis, whereas it seems to favor the ossification process in osteoblasts and bone. Further studies are needed to decipher the opposing effects observed locally in enthesis and systemically in bone in SpA.

Role of the stromal vascular fraction from adipose tissue in association with a phosphocalcic scaffold in bone regeneration in an irradiated area.

BACKGROUND: Osteoradionecrosis of the jaw is a major side-effect of radiotherapy used in the treatment of squamous cell carcinomas of the upper aerodigestive tract. The standard reconstruction procedure is a free flap transfer of autogenous bone. A new approach using a tissue engineering strategy has shown that total bone marrow (TBM) associated with biphasic calcium phosphate (BCP) is the best combination for bone regeneration in an irradiated area. Recently, the stromal vascular fraction from adipose tissue (SVF) was described as an alternative to TBM for promoting new bone formation. The aim of this study was to identify the capacity of a freshly isolated SVF to induce new bone formation in an irradiated area. METHODS: Four weeks after irradiation of the hind limbs of 15 rats, bone defects were created and filled with either SVF or TBM with and without BCP. RESULTS: Three weeks after the implantations, analysis showed that the BCP-TBM mixture improved new bone formation after radiation (p < 0.05). The BCP-SVF association induced significant neoangiogenesis but failed to enhance new bone formation. CONCLUSION: The BCP-SVF mixture was insufficient to enhance new bone formation in the irradiated area, suggesting that the role of the environment might be crucial for ossification.

Micro-CT Analysis of Radiation-Induced Osteopenia and Bone Hypovascularization in Rat.

Treatment of carcinomas of the upper aerodigestive tract often requires external radiation therapy. However, radiation affects all the components of bone, with different degrees of sensitivity, and may produce severe side effects such as mandibular osteoradionecrosis (ORN). Intraosseous vascularization is thought to be decreased after irradiation, but its impact on total bone volume is still controversial. The aim of this study was to compare intraosseous vascularization, cortical bone thickness, and total bone volume in a rat model of ORN versus nonirradiated rats, using a micro-computed tomography (micro-CT) analysis after intracardiac injection of a contrast agent. The study was performed on 8-week-old Lewis 1A rats (n = 14). Eleven rats underwent external irradiation on the hind limbs by a single 80-Gy dose. Three rats did not receive irradiation and served as controls for statistical analysis. Eight weeks after the external irradiation, all the animals received a barium sulfate intracardiac injection under general anesthesia. All samples were analyzed with the micro-computed tomography system at a resolution of 5.5 µm. The images were later processed to create 3D reconstructions and study vascularization, bone volume, and cortical thickness. Data from irradiated and nonirradiated rats were compared using the Kruskal-Wallis test. No animal died after irradiation. Nineteen irradiated tibias and six nonirradiated tibias were included for micro-CT analysis. The vessel percentage was significantly lower in irradiated bones (p = 0.0001). The distance between the vessels, a marker of vascular destruction, was higher after irradiation (p = 0.001). The vessels were also more altered distally after irradiation (p = 0.028). Cortical thickness was severely decreased after irradiation, sometimes even reduced to zero. Both trabecular and cortical structures were destroyed after irradiation, with wide bone gaps. Finally, both total bone volume (p = 0.0001) and cortical thickness (p = 0.0001) were significantly decreased in irradiated tibias compared to nonirradiated tibias. These results led to multiple spontaneous fractures in the irradiated group, and the destruction of intraosseous vessels observed macroscopically with the radiographic preview. This study revealed the impact of radiation on intraosseous vasculature and cortical bone with a micro-CT analysis in a rat ORN model. Hypovascularization and osteopenia are consistent with the literature, contributing a morphological scale with high resolution. Visualization of the vasculature by micro-CT is an innovative technique to see the changes after radiation, and should help adjust bone tissue engineering in irradiated bone.

Micro-CT scan, electron microscopy and optical microscopy study of insertional traumas of cochlear implants.

PURPOSE: Knowledge of cochlear trauma resulting from the implantation of electrodes is important for the development of atraumatic surgical techniques. The purpose of this study was to demonstrate the advantages of micro-CT scanning, back-scattered electron microscopy (BSEM) and optical microscopy (OM) in understanding the mechanisms of cochlear trauma due to cochlear implantation. METHOD: Our study involved six petrous bones removed from fresh human cadavers: one control specimen plus five other specimens that were surgically implanted with Neurelec Digisonic SP EVO electrode arrays. All six specimens underwent glycol methyl methacrylate embedding, were examined via micro-CT scan and were then sectioned for histological analysis of undecalcified samples via BSEM and OM. RESULTS: The 2D micro-CT scan reconstructions did not display cochlear microtrauma due to a limited resolution and the loss of information caused by the metallic artifacts of the intracochlear electrodes. The 3D reconstructions displayed the quality of the electrode array positioning in the cochlea and enabled determining the axes on which to section the specimens for histological examination. BSEM afforded a clear view of the damage to the osseous structures of the cochlea, but did not display the soft tissue injuries. OM enabled viewing and grading the histological lesions resulting from insertion. CONCLUSION: In our opinion, the combination of 3D micro-CT scan reconstructions and histological analysis using OM appears to be the best method to analyze this type of trauma.

Development of a cyclosporin-A-induced immune tolerant rat model to test marrow allograft cell type effects on bone repair.

Bone repair is an important concept in tissue engineering, and the ability to repair bone in hypotrophic conditions such as that of irradiated bone, represents a challenge for this field. Previous studies have shown that a combination of bone marrow and (BCP) was effective to repair irradiated bone. However, the origin and role played by each cell type in bone healing still remains unclear. In order to track the grafted cells, the development of an animal model that is immunotolerant to an allograft of bone marrow would be useful. Furthermore, because the immune system interacts with bone turnover, it is of critical importance to demonstrate that immunosuppressive drugs do not interfere with bone repair. After a preliminary study of immunotolerance, cyclosporin-A was chosen to be used in immunosuppressive therapy. Ten rats were included to observe qualitative and quantitative bone repair 8 days and 6 weeks after the creation of bone defects. The defects were filled with an allograft of bone marrow alone or in association with BCP under immunosuppressive treatment (cyclosporin-A). The results showed that there was no significant interaction of cyclosporin-A with osseous regeneration. The use of this new immunotolerant rat model of bone marrow allograft in future studies will provide insight on how the cells within the bone marrow graft contribute to bone healing, especially in irradiated conditions.

Functionalisation of Polysaccharides for the Purposes of Electrospinning: A Case Study Using HPMC and Si-HPMC.

Hydrogels are a suitable scaffold material for a variety of tissue engineering applications. However, these materials have a weak structure and require reinforcement. Integrating electrospun fibers could strengthen material properties. This study created fibers and evaluated the influence of the presence of polar head groups within a polysaccharide backbone following functionalization: silated-hydroxypropyl methylcellulose (Si-HPMC). Electrospinning is a multi-parameter, step by step process that requires optimization of solution and process parameters to understand and control the process. Fibers were created for 2%⁻3% wt/v solutions in water and ethanol. Viscosities of solutions were correlated with spinnability. Variations on process parameters did not reveal major variation on fiber morphology. Once controlled, the process was used for HPMC/Si-HPMC mixture solutions. Solubilization and dilution of Si-HPMC were made with common solvents for electrospinning. Two forms of polymer conformation were electrospun: silanol ending and silanolate ending. Microstructures and resulting nanofibers were analyzed by scanning electron microscopy (SEM) and Energy Dispersive Analysis (EDX). The results show the feasibility of our strategy for creating nanofibers and the influence of polar head groups on electrospinnability.

Crushed and injected buprenorphine tablets: characteristics of princeps and generic solutions.

Self-injection of high-dose buprenorphine is responsible for well-described complications. In 2011, we have been alerted by unusual but serious cutaneous complication among injection buprenorphine users. A prospective data collection identified 30 cases of necrotic cutaneous lesions after injection of filtered buprenorphine solution, among which 25 cases occurred following injection of buprenorphine generics. The main goal of our study was to put forward particularities that could explain the cutaneous complications, by qualitatively and quantitatively confronting particles present in Subutex and generics solutions. We used the same protocol that injected-buprenorphine users: generic or subutex tablets were crushed in sterile water and filtered through 2 filters commonly used (cotton-pad and sterifilt). Solutions were analyzed by laser granulometry, flow cytometry and scanning electron microscopy. We have highlighted the wide variation of the quantity and the size of the particles present in solution between the two drugs after cotton-pad filtration. The proportion of particles <10 µm is systematically higher in the generic solutions than with Subutex. All of the insoluble particles found in generic solutions contain silica, whereas non- organic element was to be identified in the insoluble particles of Subutex. One skin biopsy obtained from one patient who developed a necrotic lesion after intravenous injection of filtrated solution of buprenorphine generic, shows non-organic elements. Identification of particles in situ enables us to confirm the presence of silica in the biopsy. Actually the monitoring of patient receiving generic of buprenorphine must be strengthened.

Vertebroplasty using bisphosphonate-loaded calcium phosphate cement in a standardized vertebral body bone defect in an osteoporotic sheep model.

In the context of bone regeneration in an osteoporotic environment, the present study describes the development of an approach based on the use of calcium phosphate (CaP) bone substitutes that can promote new bone formation and locally deliver in situ bisphosphonate (BP) directly at the implantation site. The formulation of a CaP material has been optimized by designing an injectable apatitic cement that (i) hardens in situ despite the presence of BP and (ii) provides immediate mechanical properties adapted to clinical applications in an osteoporotic environment. We developed a large animal model for simulating lumbar vertebroplasty through a two-level lateral corpectomy on L3 and L4 vertebrae presenting a standardized osteopenic bone defect that was filled with cements. Both 2-D and 3-D analysis of microarchitectural parameters demonstrated that implantation of BP-loaded cement in such vertebral defects positively influenced the microarchitecture of the adjacent trabecular bone. This biological effect was dependent on the distance from the implant, emphasizing the in situ effect of the BP and its release from the cement. As a drug device combination, this BP-containing apatitic cement shows good promise as a local approach for the prevention of osteoporotic vertebral fractures through percutaneous vertebroplasty procedures.

Notchless is required for axial skeleton formation in mice.

Maintenance of cell survival is essential for proper embryonic development. In the mouse, Notchless homolog 1 (Drosophila) (Nle1) is instrumental for survival of cells of the inner cell mass upon implantation. Here, we analyze the function of Nle1 after implantation using the Meox2(tm1(cre)Sor) mouse that expresses the Cre recombinase specifically in the epiblast at E5.5. First, we find that NLE1 function is required in epiblast cells, as Nle1-deficient cells are rapidly eliminated. In this report, we also show that the Meox2(Cre) transgene is active in specific tissues during organogenesis. In particular, we detect high Cre expression in the vertebral column, ribs, limbs and tailbud. We took advantage of this dynamic expression profile to analyze the effects of inducing mosaic deletion of Nle1 in the embryo. We show that Nle1 deletion in this context, results in severe developmental anomalies leading to lethality at birth. Mutant embryos display multiple developmental defects in particular during axial skeletal formation. We also provide evidence that axial defects are due to an increase in apoptotic cell death in the somite at E9.5. These data demonstrate an essential role for Nle1 during organogenesis and in particular during axial development.

A novel injectable, cohesive and toughened Si-HPMC (silanized-hydroxypropyl methylcellulose) composite calcium phosphate cement for bone substitution.

This study reports on the incorporation of the self-setting polysaccharide derivative hydrogel (silanized-hydroxypropyl methylcellulose, Si-HPMC) into the formulation of calcium phosphate cements (CPCs) to develop a novel injectable material for bone substitution. The effects of Si-HPMC on the handling properties (injectability, cohesion and setting time) and mechanical properties (Young's modulus, fracture toughness, flexural and compressive strength) of CPCs were systematically studied. It was found that Si-HPMC could endow composite CPC pastes with an appealing rheological behavior at the early stage of setting, promoting its application in open bone cavities. Moreover, Si-HPMC gave the composite CPC good injectability and cohesion, and reduced the setting time. Si-HPMC increased the porosity of CPCs after hardening, especially the macroporosity as a result of entrapped air bubbles; however, it improved, rather than compromised, the mechanical properties of composite CPCs, which demonstrates a strong toughening and strengthening effect. In view of the above, the Si-HPMC composite CPC may be particularly promising as bone substitute material for clinic application.

Pomegranate and its derivatives can improve bone health through decreased inflammation and oxidative stress in an animal model of postmenopausal osteoporosis.

PURPOSE: Recently, nutritional and pharmaceutical benefits of pomegranate (PG) have raised a growing scientific interest. Since PG is endowed with anti-inflammatory and antioxidant activities, we hypothesized that it may have beneficial effects on osteoporosis. METHODS: We used ovariectomized (OVX) mice as a well-described model of postmenopausal osteoporosis to study the influence of PG consumption on bone health. Mice were divided into five groups as following: two control groups sham-operated and ovariectomized (OVX CT) mice fed a standard diet, versus three treated groups OVX mice given a modified diet from the AIN-93G diet, containing 5.7% of PG lyophilized mashed totum (OVX PGt), or 9.6% of PG fresh juice (OVX PGj) or 2.9% of PG lyophilized mashed peel (OVX PGp). RESULTS: As expected, ovariectomy was associated with a decreased femoral bone mineral density (BMD) and impaired bone micro-architecture parameters. Consumption of PGj, PGp, or PGt induced bone-sparing effects in those OVX mice, both on femoral BMD and bone micro-architecture parameters. In addition, PG (whatever the part) up-regulated osteoblast activity and decreased the expression of osteoclast markers, when compared to what was observed in OVX CT animals. Consistent with the data related to bone parameters, PG consumption elicited a lower expression of pro-inflammatory makers and of enzymes involved in ROS generation, whereas the expression of anti-inflammatory markers and anti-oxidant actors was enhanced. CONCLUSION: These results indicate that all PG parts are effective in preventing the development of bone loss induced by ovariectomy in mice. Such an effect could be partially explained by an improved inflammatory and oxidative status.

Novel and simple alternative to create nanofibrillar matrices of interest for tissue engineering.

Synthetic analogs to natural extracellular matrix (ECM) at the nanometer level are of great potential for regenerative medicine. This study introduces a novel and simple method to produce polymer nanofibers and evaluates the properties of the resulting structures, as well as their suitability to support cells and their potential interest for bone and vascular applications. The devised approach diffracts a polymer solution by means of a spraying apparatus and of an airstream as sole driving force. The resulting nanofibers were produced in an effective fashion and a factorial design allowed isolating the processing parameters that control nanofiber size and distribution. The nanofibrillar matrices revealed to be of very high porosity and were effectively colonized by human bone marrow mesenchymal cells, while allowing ECM production and osteoblastic differentiation. In vivo, the matrices provided support for new bone formation and provided a good patency as small diameter vessel grafts.