Multi-functional osteoclasts in matrix-based tissue engineering bone.

The repair of bone defects, especially for the large segment of bone defects, has always been an urgent problem in orthopedic clinic and attracted researchers' attention. Nowadays, the application of tissue engineering bone in the repair of bone defects has become the research hotspot. With the rapid development of tissue engineering, the novel and functional scaffold materials for bone repair have emerged.

Inhibitory effect of dihydroartemisinin on chondrogenic and hypertrophic differentiation of mesenchymal stem cells.

Chondrocytes located in hyaline cartilage may maintain phenotype while the chondrocytes situated in calcified cartilage differentiate into hypertrophy. Chondrogenic and hypertrophic differentiation of mesenchymal stem cells (MSCs) are two subsequent processes during endochondral ossification. However, it is necessary for chondrocytes to hold homeostasis and to inhibit hypertrophic differentiation in stem cell-based regenerated cartilage.

A novel axial-stress bioreactor system combined with a substance exchanger for tissue engineering of 3D constructs.

This study introduced a prototype of an axial-stress bioreactor system that supports long-term growth and development of engineered tissues. The main features of this bioreactor are an integrated substance exchanger and feedback control of pH and PO₂. A 21-day study was conducted to validate the system's ability to maintain a stable environment, while remaining sterile.

Piezoelectric PU/PVDF electrospun scaffolds for wound healing applications.

Previous studies have shown that piezoelectric materials may be used to prepare bioactive electrically charged surfaces. In the current study, polyurethane/polyvinylidene fluoride (PU/PVDF) scaffolds were prepared by electrospinning. The mechanical property and piezoelectric property of the scaffolds were evaluated.

Synergy of tendon stem cells and platelet-rich plasma in tendon healing.

Injured rat Achilles tendons were treated with botulism toxin to create a mechanically unloaded condition (unloaded) or left untreated (loaded), and then treated with phosphate-buffered saline (PBS), platelet-rich plasma (PRP), tendon stem cells (TSCs), or a combination (TSCs + PRP). mRNA and protein expression of collagen I, collagen III, tenascin C, and Smad 8 were determined by real time PCR and immunostaining, respectively. Loaded tendons treated with PBS, PRP, or TSCs for 3 or 14 days had higher collagen I mRNA expression than unloaded tendons.

[Effects of different cyclic mechanical stretching loads on human tenocytic cytoskeleton in vitro].

Objective: To investigate the human tenocyte cytoskeleton under different in vitro stretching conditions and analyze the relations between the changes of tenocytic cytoskeleton and different stretching loads.

Methods: Human tenocytes, cultivated for 5 -7 passages, were stretched under 4%, 8% and 12% cyclic mechanical stretching with a duration of 2, 4, 8, 12, 24 hours and a frequency of 0.5 and 1.

Bone marrow mesenchymal stem cells can be mobilized into peripheral blood by G-CSF in vivo and integrate into traumatically injured cerebral tissue.

The efficacy of granulocyte colony-stimulating factor (G-CSF) in mobilizing mesenchymal stem cells (MSCs) into peripheral blood (PB) and the ability of PB-MSCs incorporated into injured brain were tested. Colony forming, cell phenotype and differentiation potential of mouse MSCs mobilized by G-CSF (40 μg/kg) were evaluated. Mortality and pathological changes in mice with serious craniocerebral trauma plus G-CSF treatment (40 μg/kg) were investigated.

Effect of hBD2 genetically modified dermal multipotent stem cells on repair of infected irradiated wounds.

Deficiencies in repair cells and infection are two of the main factors that can hinder the process of wound healing. In the present study, we investigated the ability of human beta-defensin-2 (hBD2) genetically modified dermal multipotent stem cells (dMSCs) to accelerate the healing irradiated wounds complicated by infections. An hBD2 adenovirus expression vector (Adv-hBD2) was firstly constructed and used to infect dMSCs.

Bone regeneration using an acellular extracellular matrix and bone marrow mesenchymal stem cells expressing Cbfa1.

To treat bone defects, tissue-engineering methods combine an appropriate scaffold with cells and osteogenic signals to stimulate bone repair. Mesenchymal stem cells (MSCs) derived from adult bone marrow are an ideal source of cells for tissue engineering, in particular for applications in skeletal and hard tissue repair. Core binding factor alpha1 (Cbfa1) is an essential transcription factor for osteoblast differentiation.

CXCR4 gene transfer enhances the distribution of dermal multipotent stem cells to bone marrow in sublethally irradiated rats.

Our previous study indicated that systemically transplanted dermal multipotent cells (DMCs) were recruited more frequently to bone morrow (BM) of rats with sublethal irradiation than that of normal rats, and the interactions between stromal-derived factor (SDF-1) and its receptor (CXC chemokine receptor 4, CXCR4) played an important role in this process. In the present study, we aimed to investigate whether CXCR4 gene transfer could promote the distribution of DMCs into irradiated BM and accelerate its function recovery. Firstly, adenovirus vector of CXCR4 (Adv-CXCR4) and green fluorescent protein (Adv-GFP) were constructed.

Recruitment of transplanted dermal multipotent stem cells to sites of injury in rats with combined radiation and wound injury by interaction of SDF-1 and CXCR4.

Systemic transplantation of dermal multipotent stem cells has been shown to accelerate both hematopoietic recovery and wound healing in rats with combined radiation and wound injury. In the present study, we explored the mechanisms governing the recruitment of dermal multipotent stem cells to the sites of injury in rats with combined injury. Male dermal multipotent stem cells were transplanted into female rats, and using quantitative real-time PCR for the sex-determining region of Y chromosome, it was found that the amounts of dermal multipotent stem cells in irradiated bone marrow and wounded skin were far greater than those in normal bone marrow and skin (P < 0.

Effects of peritoneal lavage fluid from radiation or/and burn injured rats on the growth of hematopoietic progenitor cells.

Purpose: To evaluate the effects of peritoneal lavage fluids from radiation injury, burn injury and combined radiation-burn injury on the growth of hematopoietic progenitor cells (HPC).

Materials And Methods: Rats were divided into four groups: A radiation group (RG), a burn group (BG), a combined radiation-burn group (CRBG) and normal control group (NG). RG and CRBG rats were irradiated with 12 Gy, and burns of 30% total body surface area were generated in group BG and group CRBG.

The zinc finger protein A20 protects endothelial cells from burns serum injury.

Burn injuries as well as skin damages are often associated with immune suppression and often cause multiple organ failures. The monolayer endothelium is vulnerable to injuries from circulating factors resulting from remote wounds. Endothelial cell activation and apoptosis can alter microvascular permeability and intensify organ damage.