Rosamultin Attenuates Acute Hypobaric Hypoxia-Induced Bone Injuries by Regulation of Sclerostin and Its Downstream Signals.

Wang, Xing-Min, Hui Liu, Jian-Yu Li, Jin-Xia Wei, Xia Li, Yong-Liang Zhang, Ling-Zhi Li, and Xi-Zheng Zhang. Rosamultin attenuates acute hypobaric hypoxia-induced bone injuries by regulation of sclerostin and its downstream signals. 21:273-286, 2020.

Mechanical property and biocompatibility of silk fibroin-collagen type II composite membrane.

Osteoarthritis is caused by injuries and cartilage degeneration. Cartilage tissue engineering provides new ideas for the treatment of osteoarthritis. Herein, the different ratios composite membranes of silk fibroin/collagen type II were constructed (SF50-50:50, SF70-70:30, SF90-90:10).

Effects of constrained dynamic loading, CKIP‑1 gene knockout and combination stimulations on bone loss caused by mechanical unloading.

Mechanical stimulation plays an important role in maintaining the growth and normal function of the skeletal system. Mechanical unloading occurs, for example, in astronauts spending long periods of time in space or in patients on prolonged bed rest, and causes a rapid loss of bone mass. Casein kinase 2‑interacting protein‑1 (CKIP‑1) is a novel negative bone regulation factor that has been demonstrated to reduce bone loss and enhance bone formation.

The Combination of icariin and constrained dynamic loading stimulation attenuates bone loss in ovariectomy-induced osteoporotic mice.

Osteoporosis is a disease characterized by low bone mass and progressive destruction of bone microstructure, resulting in increasing the risk of fracture. Icariin (ICA) as a phytoestrogen shows osteogenic effects, and the mechanical stimulation has been demonstrated the improving effect on osteoporosis. The objective of this study was to investigate the effect of ICA in combination with constrained dynamic loading (CDL) stimulation on osteoporosis in ovariectomized (OVX) mice.

Effect of athletic fatigue damage and the associated bone targeted remodeling in the rat ulna.

Background: Fatigue damage of the long bones is prevalent in running athletes and military recruits due to vigorous mid- and long-term physical activity. The current study attempted to know the features of bony athletic fatigue damage and to explore the mechanism of fatigue damage repair through bone targeted remodeling process.

Methods: Right ulnae of the Wistar rats were fatigue loaded on an INSTRON 5865 to construct the athletic fatigue damage model, and several time points (i.

Ratcheting behavior of articular cartilage under cyclic unconfined compression.

The ratcheting deformation of articular cartilage can produce due to the repeated accumulations of compressive strain in cartilage. The aim of this study was to investigate the ratcheting behavior of articular cartilage under cyclic compression. A series of uniaxial cyclic compression tests were conducted for online soaked and unsoaked cartilage samples and the effects of stress variation and stress rate on ratcheting behavior of cartilage were investigated.

A comparative study of mechanical strain, icariin and combination stimulations on improving osteoinductive potential via NF-kappaB activation in osteoblast-like cells.

Background: The combination of drugs and exercise was the effective treatment in bone injure and rebuilding in clinic. As mechanical strain has potential in inducing the differentiation of osteoblasts in our previous study, the further research to investigate the combination of mechanical strain and icariin stimulation on inducing osteoblast proliferation, differentiation and the possible mechanism in MC3T3-E1 cell line.

Methods: A whole cell enzyme-linked immunosorbent assay that detects the bromodeoxyuridine incorporation during DNA synthesis was applied to evaluate the proliferation.

Reduction of the pro-inflammatory response by tetrandrine-loading poly(L-lactic acid) films in vitro and in vivo.

Inflammatory response of implantable biomaterials and drug delivery vehicles, driven by the reaction of macrophages to foreign body particles released from the implant, is an urgent problem to resolve. Despite this, little is known about the inflammatory molecular mechanism following the implantation of biomaterials and the evaluation of anti-inflammatory biomaterials. In this study, tetrandrine (TET) was loaded into poly (l-lactic acid) (PLLA) films to assess the anti-inflammatory effects in vitro and in vivo.

Mechanical stimulus inhibits the growth of a bone tissue model cultured in vitro △.

Objectives: To construct the cancellous bone explant model and a method of culturing these bone tissues in vitro, and to investigate the effect of mechanical load on growth of cancellous bone tissue in vitro.

Methods: Cancellous bone were extracted from rabbit femoral head and cut into 1-mm-thick and 8-mm-diameter slices under sterile conditions. HE staining and scanning electron microscopy were employed to identify the histomorphology of the model after being cultured with a new dynamic load and circulating perfusion bioreactor system for 0, 3, 5, and 7 days, respectively.

Extracellular matrix of mechanically stretched cardiac fibroblasts improves viability and metabolic activity of ventricular cells.

Background: In heart, the extracellular matrix (ECM), produced by cardiac fibroblasts, is a potent regulator of heart's function and growth, and provides a supportive scaffold for heart cells in vitro and in vivo. Cardiac fibroblasts are subjected to mechanical loading all the time in vivo. Therefore, the influences of mechanical loading on formation and bioactivity of cardiac fibroblasts ECM should be investigated.

Bone formation in rabbit cancellous bone explant culture model is enhanced by mechanical load.

Background: When studying and designing an artificial bone in vitro with similar features and functionality of natural bone by tissue engineering technology, the culturing environment, especially the mechanical environment is supposed to be an important factor, because a suitable mechanical environment in vitro may improve the adaptability of the planted-in tissue engineering bone in the body. Unfortunately, up to now, the relationship between mechanical stimuli and natural bone growth has not yet been precisely determined, and it is so imperative for a prior study on effect of mechanical loading on growth of the natural bone cultured in vitro.

Methods: Under sterile conditions, explant models of rabbit cancellous bone with 3 mm in thickness and 8 mm in diameter were prepared and cultured in a dynamic loading and circulating perfusion bioreactor system.

Counter-effect of constrained dynamic loading on osteoporosis in ovariectomized mice.

In recent years, dynamic mechanical loading has been shown to effectively enhance bone remodeling. The current study attempted to research the counter-effect of constrained dynamic loading on osteoporosis (OP) in ovariectomized (OVX) mice. Female Kunming (KM) mice were randomly divided into 2 groups: SHAM and OVX.

Cardiac fibroblast-derived extracellular matrix produced in vitro stimulates growth and metabolism of cultured ventricular cells.

Cardiac fibroblasts (CFs) produce extracellular matrix (ECM) which is a potent regulator of heart cell function and growth, and provides a supportive microenvironment for heart cells. Therefore, CF-derived ECM produced in vitro is very suitable for heart-cell culturing and cardiac tissue engineering. The aim of this study was to investigate the effect of CF-derived ECM produced in vitro on the growth and metabolism of cultured ventricular cells.

Mechanical strain promotes osteoblast ECM formation and improves its osteoinductive potential.

Background: The extracellular matrix (ECM) provides a supportive microenvironment for cells, which is suitable as a tissue engineering scaffold. Mechanical stimulus plays a significant role in the fate of osteoblast, suggesting that it regulates ECM formation. Therefore, we investigated the influence of mechanical stimulus on ECM formation and bioactivity.

Differential effects of mechanical strain on osteoclastogenesis and osteoclast-related gene expression in RAW264.7 cells.

Mechanical strain plays a critical role in the formation, proliferation and maturation of bone cells. However, little is known about the direct effects of different magnitudes of mechanical strain on osteoclast differentiation. The aim of the present study was to investigate how the fusion and activation of osteoclasts can be regulated by mechanical strain magnitude using the RAW264.

Mechanical strain regulates osteoblast proliferation through integrin-mediated ERK activation.

Mechanical strain plays a critical role in the proliferation, differentiation and maturation of bone cells. As mechanical receptor cells, osteoblasts perceive and respond to stress force, such as those associated with compression, strain and shear stress. However, the underlying molecular mechanisms of this process remain unclear.

Involvement of p38MAPK/NF-κB signaling pathways in osteoblasts differentiation in response to mechanical stretch.

Bone morphogenetic proteins (BMPs) are known to be important in osteoblasts' response to mechanical stimuli. BMPs/Smad signaling pathway has been demonstrated to play a regulatory role in the mechanical signal transduction in osteoblasts. However, little is currently known about the Smad independent pathway in osteoblasts differentiation in mechanical loading.

Relationship between surgical time and postoperative complications in senile patients with hip fractures.

Objective: To elucidate the relationship between surgical time and postoperative complications in senile patients with hip fractures, and try to find out other factors which are related to these complications.

Methods: Sixty-two patients, 28 males aged from 65 to 72 years with a mean age of 76.3 years and 34 females aged from 65 to 95 years with a mean age of 78.

Culturing of ventricle cells at high density and construction of engineered cardiac cell sheets without scaffold.

In natural heart tissue, cell density is about 1.0 x 108/cm3, and the cell metabolism is very active. Therefore, culturing heart cells in 3-dimensions at high density and construction of engineered cardiac tissue in vitro is very difficult.

The establishment of a mechanobiology model of bone and functional adaptation in response to mechanical loading.

Background: Mechanical stimuli affected bone adaptation, however, the mechanism on a dose-response relationship between mechanical stimuli and bone response is unclear. Therefore, we established a mechanobiology model to evaluated the adaptive response of bone to strain deformation at high-frequencies (5-15 Hz) of externally applied strain.

Methods: The ulnae of adult female rats were subjected to dynamic axial loading in vivo using Instron materials-testing machine.

[The establishment of a new mechanobiology model of bone and functional adaptation studies in vivo].

Objectives: to study the functional adaptation in response to artificial loading in vivo.

Methods: A single element strain gauge of < 2 mm x 3 mm in size was attached in longitudinal alignment to the medial surface of the ulnar midshaft, in vivo recordings of ulnar strains during locomotion were obtained. The ulnae of natural female rats were subjected to dynamic axial loading in vivo simulate strains during locomotion using INSTRON materials-testing machine.

Construction of a unidirectionally beating 3-dimensional cardiac muscle construct.

Background: Cardiac tissue engineering aims to construct cardiac tissue with characteristics similar to those of the native tissue. Engineered cardiac tissues (ECTs) can be constructed using synthetic scaffold or liquid collagen. We report an initial study using our own newly designed cardiac muscle device to construct heart tissue.

[Experimental study of tissue-engineered heart tissue using type I collagen as scaffold].

Objective: To construct tissue-engineered heart tissue (EHT) using liquid collagen as scaffold.

Methods: Neonatal rat cardiac myocytes were isolated, cultured, and mixed with liquid collagen type I and matrix factors and then cast in circular molds to construct circular cardiac myocytes/collagen strand. After a 7-day culture in circular molds, the strands were removed, and subjected to 10% static stretch for another 7 days.

[The expression of lung nitric oxide synthase in rat exposed to silica].

Objective: To evaluate the time-effect of silica on the expression of lung tissue nitric oxide synthase (NOS) in early inflammatory damage stage of silicotic rat.

Methods: Animal models were established by direct tracheal instillation of silica into rat lungs. Total NOS and induced NOS (iNOS) activities in bronchoalveolar lavage fluid (BALF) were assayed.