Physical exercise impacts bone remodeling around bio-resorbable magnesium implants.

Physical exercise has been shown to induce positive reactions in bone healing but next to nothing is known about how it affects the nanostructure, in particular around implants. In this study, we established this link by using small-angle X-ray scattering tensor tomography (SASTT) to investigate nanostructural parameters in 3D such as mineral particle orientation and thickness. As a model system, rat femoral bone with a bio-resorbable implant (ultra-high purity magnesium) was used.

Development of a Dual Reporter System to Simultaneously Visualize Ca Signals and AMPK Activity.

In this study, we introduce a new separation of phases-based activity reporter of kinase (SPARK) for AMP-activated kinase (AMPK), named AMPK-SPARK, which reports the AMPK activation by forming bright fluorescent clusters. Furthermore, we introduce a dual reporter system, named GCaMP-AMPK-SPARK, by incorporating a single-fluorescent protein (FP)-based Ca biosensor, GCaMP6f, into our initial design, enabling simultaneous monitoring of Ca levels and AMPK activity. This system offers the essential quality of information by single-channel fluorescence microscopy without the need for coexpression of different biosensors and elaborate filter layouts to overcome spectral limitations.

Does early post-operative exercise influence bone healing kinetics? Preclinical evaluation of non-critical sized femur defect healing.

Physical exercise is a well-known modality for maintaining healthy locomotor mechanism. A detailed preclinical research on physical exercise effect on bone healing kinetics could help to improve the rehabilitation process after fracture treatment and bone remodeling. Our aim was to evaluate the effect of early post-operative exercise effect on bone microstructural changes in a rat model.

Newly Developed Resorbable Magnesium Biomaterials for Orbital Floor Reconstruction in Caprine and Ovine Animal Models-A Prototype Design and Proof-of-Principle Study.

Background: orbital floor fractures have not been reconstructed using magnesium biomaterials.

Methods: To test technical feasibility, ex vivo caprine and ovine heads (n = 5) were used. Head tissues were harvested from pubescent animals (n = 5; mean age: 3.

The combined effect of zinc and calcium on the biodegradation of ultrahigh-purity magnesium implants.

Magnesium (Mg)-based implants are promising candidates for orthopedic interventions, because of their biocompatibility, good mechanical features, and ability to degrade completely in the body, eliminating the need for an additional removal surgery. In the present study, we synthesized and investigated two Mg-based materials, ultrahigh-purity ZX00 (Mg-Zn-Ca; <0.5 wt% Zn and <0.

Immunological reaction to magnesium-based implants for orthopedic applications. What do we know so far? A systematic review on studies.

Magnesium-based implants (Mg) became an attractive candidate in orthopedic surgery due to their valuable properties, such as osteoconductivity, biodegradability, elasticity and mechanical strength. However, previous studies on biodegradable and non-biodegradable metal implants showed that these materials are not inert when placed as they interact with host defensive mechanisms. The aim of this study was to systematically review available studies with Mg-based implants that investigated immunological reactions to these implants.

Implant degradation of low-alloyed Mg-Zn-Ca in osteoporotic, old and juvenile rats.

Implant removal is unnecessary for biodegradable magnesium (Mg)-based implants and, therefore, the related risk for implant-induced fractures is limited. Aging, on the other hand, is associated with low bone-turnover and decreased bone mass and density, and thus increased fracture risk. Osteoporosis is accompanied by Mg deficiency, therefore, we hypothesized that Mg-based implants may support bone formation by Mg ion release in an ovariectomy-induced osteoporotic rat model.

Increased Staphylococcus aureus Biofilm Formation on Biodegradable Poly(3-Hydroxybutyrate)-Implants Compared with Conventional Orthopedic Implants: An In Vitro Analysis.

Objective: To compare the biofilm formation on a biodegradable material, poly(3-hydroxybutyrate) (PHB), with that on conventional titanium (Ti) and steel (St) implant material.

Methods: Pins made of the different materials were incubated in Müller-Hinton broth inoculated with 2 × 10 colony-forming units (CFU)·mL of Staphylococcus aureus for 2 and 7 days and then sonicated for the disruption of the biofilms. CFU were counted to quantify the number of bacteria in the biofilm, and the cell proliferation assay 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H- tetrazolium-5-carboxanilid salt was used to evaluate their metabolic activity.

A 300 μm Organotypic Bone Slice Culture Model for Temporal Investigation of Endochondral Osteogenesis.

Translational studies to elucidate the response of immature bone to biologic and physical stimuli have been held back by the lack of a viable long-term functional bone explant model. This study attempts to bridge this gap between cell culture and animal model studies. In this study, we describe a methodology to derive a 300 μm organotypic femur slice comprising physiological zones (epiphysis and meta-diaphysis) essential for endochondral bone development.

The influence of biodegradable magnesium implants on the growth plate.

Unlabelled: Mg-based biodegradable materials are considered promising candidates in the paediatric field due to their favourable mechanical and biological properties and their biodegrading potential that makes a second surgery for implant removal unnecessary. In many cases the surgical fixation technique requires a crossing of the growth plate by the implant in order to achieve an adequate fragment replacement or fracture stabilisation. This study investigates the kinetics of slowly and rapidly degrading Mg alloys in a transphyseal rat model, and also reports on their dynamics in the context of the physis and consecutive bone growth.

µXRF Elemental Mapping of Bioresorbable Magnesium-Based Implants in Bone.

This study investigated the distribution of the elemental constituents of Mg-based implants at various stages of the degradation process in surrounding bone tissue, with a focus on magnesium (Mg), as the main component of the alloy, and yttrium (Y), due to its potential adverse health effects. The measurements were performed on the implant-bearing thin sections of rat bone in a time series of implant degradation between one and 18 months. Micro X-ray fluorescence analysis (μXRF) with a special spectrometer meeting the requirements for the measurements of low-Z elements was used.

The potential of isotopically enriched magnesium to study bone implant degradation in vivo.

Unlabelled: This pilot study highlights the substantial potential of using isotopically enriched (non-radioactive) metals to study the fate of biodegradable metal implants. It was possible to show that magnesium (Mg) release can be observed by combining isotopic mass spectrometry and isotopic pattern deconvolution for data reduction, even at low amounts of Mg released a from slowly degrading Mg enriched (>99%) Mg metal. Following implantation into rats, structural in vivo changes were monitored by μCT.

Gadolinium accumulation in organs of Sprague-Dawley® rats after implantation of a biodegradable magnesium-gadolinium alloy.

Unlabelled: Biodegradable magnesium implants are under investigation because of their promising properties as medical devices. For enhancing the mechanical properties and the degradation resistance, rare earth elements are often used as alloying elements. In this study Mg10Gd pins were implanted into Sprague-Dawley® rats.

Time-Dependent Changes in T1 during Fracture Healing in Juvenile Rats: A Quantitative MR Approach.

Quantitative magnetic resonance imaging (qMRI) offers several advantages in imaging and determination of soft tissue alterations when compared to qualitative imaging techniques. Although applications in brain and muscle tissues are well studied, its suitability to quantify relaxation times of intact and injured bone tissue, especially in children, is widely unknown. The objective observation of a fracture including its age determination can become of legal interest in cases of child abuse or maltreatment.

Clinical impact of interleukin 6 as a predictive biomarker in the early diagnosis of postoperative systemic inflammatory response syndrome after major thoracic surgery: A prospective clinical trial.

Background: Postoperative systemic inflammatory response syndrome and sepsis are associated with high morbidity and mortality rates. Early detection of postoperative systemic inflammatory response syndrome improves the outcome. The aim of this study was to evaluate the feasibility of interleukin 6 as a predictive biomarker in the early diagnosis of postoperative systemic inflammatory response syndrome after a major thoracic operation.

Biomarkers of Chondrocyte Apoptosis and Autophagy in Osteoarthritis.

Cell death with morphological and molecular features of apoptosis has been detected in osteoarthritic (OA) cartilage, which suggests a key role for chondrocyte death/survival in the pathogenesis of OA. Identification of biomarkers of chondrocyte apoptosis may facilitate the development of novel therapies that may eliminate the cause or, at least, slow down the degenerative processes in OA. The aim of this review was to explore the molecular markers and signals that induce chondrocyte apoptosis in OA.

Extra-virgin olive oil diet and mild physical activity prevent cartilage degeneration in an osteoarthritis model: an in vivo and in vitro study on lubricin expression.

Mediterranean diet includes a relatively high fat consumption mostly from monounsaturated fatty acids mainly provided by olive oil, the principal source of culinary and dressing fat. The beneficial effects of olive oil have been widely studied and could be due to its phytochemicals, which have been shown to possess anti-inflammatory properties. Lubricin is a chondroprotective glycoprotein and it serves as a critical boundary lubricant between opposing cartilage surfaces.

Cellular reactions to biodegradable magnesium alloys on human growth plate chondrocytes and osteoblasts.

Purpose: In recent decades operative fracture treatment using elastic stable intramedullary nails (ESINs) has mainly taken precedence over conservative alternatives in children. The development of biodegradable materials that could be used for ESINs would be a further step towards treatment improvement. Due to its mechanical and elastic properties, magnesium seems to be an ideal material for biodegradable implant application.

Post-traumatic caspase-3 expression in the adjacent areas of growth plate injury site: a morphological study.

The epiphyseal plate is a hyaline cartilage plate that sits between the diaphysis and the epiphysis. The objective of this study was to determine the impact of an injury in the growth plate chondrocytes through the study of histological morphology, immunohistochemistry, histomorphometry and Western Blot analyses of the caspase-3 and cleaved PARP-1, and levels of the inflammatory cytokines, Interleukin-6 (IL-6) and Tumor Necrosis Factor alpha (TNF-α), in order to acquire more information about post-injury reactions of physeal cell turnover. In our results, morphological analysis showed that in experimental bones, neo-formed bone trabeculae-resulting from bone formation repair-invaded the growth plate and reached the metaphyseal bone tissue (bone bridge), and this could result in some growth arrest.

Sesquiterpene lactones downregulate G2/M cell cycle regulator proteins and affect the invasive potential of human soft tissue sarcoma cells.

Soft tissue sarcomas (STS) represent a rare group of malignant tumors that frequently exhibit chemotherapeutic resistance and increased metastatic potential. Many studies have demonstrated the great potential of plant-derived agents in the treatment of various malignant entities. The present study investigates the effects of the sesquiterpene lactones costunolide and dehydrocostus lactone on cell cycle, MMP expression, and invasive potential of three human STS cell lines of various origins.

RANKL is downregulated in bone cells by physical activity (treadmill and vibration stimulation training) in rat with glucocorticoid-induced osteoporosis.

The aim of this study was to investigate bone tissue and plasma levels of RANKL and OPG in rats with prednisolone-induced osteoporosis and to evaluate the outcomes of physical activity on the skeletal system by treadmill and vibration platform training. Osteoporosis is a disease characterised by low bone mass and structural deterioration of bone tissue leading to bone fragility. Vibration exercise is a new and effective measure to prevent muscular atrophy and osteoporosis.

Fracture of the ulnar styloid process negatively influences the outcome of paediatric fractures of the distal radius.

In paediatric patients with fractures of the distal radius, the consequences of associated ulnar styloid fractures are often underestimated. These may include persisting pain or functional deficits. The aim of the present study was to report the outcome of these fractures using a modified DASH-Score.

Fractures of the pelvis in children: a review of the literature.

Trauma is the leading cause of death in children. Pelvic ring injuries account for 0.3-4% of all paediatric injuries.

The effects of physical activity on apoptosis and lubricin expression in articular cartilage in rats with glucocorticoid-induced osteoporosis.

Glucocorticoids are considered the most powerful anti-inflammatory and immunomodulating drugs. However, a number of side-effects are well documented in different diseases, including articular cartilage, where increases or decreases in the synthesis of hormone-dependent extracellular matrix components are seen. The objective of this study has been to test the effects of procedures or drugs affecting bone metabolism on articular cartilage in rats with prednisolone-induced osteoporosis and to evaluate the outcomes of physical activity with treadmill and vibration platform training on articular cartilage.

BMP-6 and BMPR-1a are up-regulated in the growth plate of the fractured tibia.

Bone overgrowth is a known phenomenon occurring after fracture of growing long bones with possible long-term physical consequences for affected children. Here, the physeal expression of bone morphogenetic proteins (BMPs) was investigated in a fracture-animal model to test the hypothesis that a diaphyseal fracture stimulates the physeal expression of these known key regulators of bone formation, thus stimulating bone overgrowth. Sprague-Dawley rats (male, 4 weeks old), were subjected to a unilateral mid-diaphyseal tibial fracture.