Tissue-engineered ribs for chest wall reconstruction: a case with 12-year follow-up.

We hereby report on a case in which a huge chest wall defect generated by resection of a massive aggressive tumor (desmoplastic fibroma) was repaired with osteogenic-induced mesenchymal stem cells embedded in a bone-derived biomaterial. In this case, there were three challenges to overcome: reconstruction of the soft tissue, repair of the skeletal defect of the thoracic wall and repair of the defect in the pleural cavity. The defects of soft tissue and pleural cavity were reconstructed, respectively, with an ipsilateral abdominal flap and a diaphragm muscular flap.

Tissue engineered esophagus scaffold constructed with porcine small intestinal submucosa and synthetic polymers.

Acellular porcine small intestinal submucosa (SIS) has been successfully used for reconstructing esophagus with half circumferential defects. However, repairing full circumferential esophageal defects with SIS has been restricted due to the latter's poor mechanical properties. In the present study, synthetic polyesters biomaterial poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(lactide-co-glycolide) (PLGA) have been used to improve the mechanical properties of SIS.

Injectable thermosensitive PEG-PCL-PEG hydrogel/acellular bone matrix composite for bone regeneration in cranial defects.

We have certified that the injectable thermosensitive ABM/PECE composite presented promising potential in bone regeneration benefited from the incorporation of the intrinsic osteoinductive acellular bone matrix (ABM) granules into the poly(ethylene glycol)-poly(ε-capro-lactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) hydrogel. In this study, the 12 mm × 8 mm × 2 mm cranial defects of the New Zealand white rabbits were fabricated to evaluate the bone regeneration effect. The ABM/PECE composite was injected into the defect while the pure PECE as control, and the bone regeneration was evaluated at 4, 12 and 20 weeks post-surgery by X-radiological examination, micro-computed tomography examination and histological analysis.

The poor osteoinductive capability of human acellular bone matrix.

Demineralized bone matrix (DBM) has extensive clinical use for bone regeneration because of its osteoinductive and osteoconductive aptitude. It is suggested that the demineralization process in bone matrix preparation is influential in maintaining osteoinductivity; however, relevant investigations, especially into the osteoinductivity of acellular bone matrix, are not often performed. This study addressed the osteoinductive capability of human acellular cancellous bone matrix (ACBM) after subcutaneous implantation in a rat model.

Tissue engineered esophagus by mesenchymal stem cell seeding for esophageal repair in a canine model.

Purpose: Acellular porcine small intestinal submucosa (SIS) has been successfully used for esophagoplasty in dogs. However, this has not led to complete epithelialization and muscular regeneration. We undertook the present study to assess the effect of tissue-engineered esophagus generated by seeding bone marrow mesenchymal stem cells (BMSCs) onto an SIS scaffold (BMSCs-SIS) in a canine model.

Placenta- versus bone-marrow-derived mesenchymal cells for the repair of segmental bone defects in a rabbit model.

Tissue-engineered bones (TEBs) constructed with bone-marrow-derived mesenchymal stem cells (BMSCs) seeded on biomaterial scaffolds have achieved good results for bone defect repair in both animal experiments and clinical trials. This has been limited, however, by the source and quantity of BMSCs. We here explored TEBs constructed by placenta-derived mesenchymal stem cells (PMSCs) and compared their effect for the repair of critical-sized segmental osteoperiosteal defects with TEBs constructed with BMSCs.

Preparation and characterization of decellularized tendon slices for tendon tissue engineering.

To develop a naturally derived tendon tissue engineering scaffold with the preservation of the native ultrastructure, tensile strength, and biochemical composition of the tendon extracellular matrix (ECM), decellularized tendon slices (DTSs) were prepared using repetitive freeze/thaw of the intact Achilles tendons, frozen section, and nuclease treatment. The DTSs were characterized in the native ultrastructure, mechanical properties, biochemical composition, and cytocompatibility. Histological examination and DNA quantification analysis confirmed that cells were completely removed from tendon tissue by repetitive freeze/thaw in combination with nuclease treatment 12 h.

Hypoxia inhibits the spontaneous calcification of bone marrow-derived mesenchymal stem cells.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are the popular seed cells for regenerative medicine, and there has been a rapid increase in the number of BM-MSC-based clinical trials. However, the safety of these cells should also be closely studied. In this study, spontaneous calcification of BM-MSCs from rats was evaluated in normoxia (20% O(2)) without osteogenic medium after continuous culture for 21 days; obvious mineralized nodules were observed, which were positive for Alizarin Red, collagen-I (Col-I), osteocalcin (OC) and alkaline phosphatase (ALP), and mainly consisted of C, O and Ca elements.

[Small intestine submucosa as a scaffold for cartilage reconstruction in vitro].

This paper is aimed to investigate the feasibility of applying the small intestine submucosa (SIS) as the scaffold in constructing tissue engineering cartilage in vitro. We obtained SIS from the small intestine of specific pathogen-free pigs. Then we isolated tunica submucosa layer from the mucosal, muscular, and serosal layers by gentle mechanic abrasion.

A multi-step method for preparation of porcine small intestinal submucosa (SIS).

Porcine small intestinal submucosa (SIS) has been widely used in repairing various tissues and organs. Despite this, some SIS products have the capacity to cause variable inflammatory responses after implantation resulting in severe adverse effects due to porcine cell existence. In this study, we described a multi-step method including mechanical disassociation, degrease, enzyme digestion, detergent treatment, freeze-drying and sterilization by irradiation for preparation of SIS.

[An experimental study on rabbit bone marrow mesenchymal stem cells double-labeled by PKH26 and 5-bromo-2'-deoxyuridine in vitro and application in cardiac patch].

Objective: To study the biological characteristic of rabbit bone marrow mesenchymal stem cells (BMSCs) double-labeled by PKH26 and BrdU in vitro, and to construct tissue engineered cardiac patch in vitro.

Methods: The BMSCs were harvested from 6-month-old New Zealand rabbits and labeled with PKH26 and BrdU. The growth and fluorescent intensity were observed by inverted phase contrast microscope, fluorescent microscope, flow cytometry, and MTT detection.

[Strain-induced tenogenic differentiation of bone marrow mesenchymal stem cells].

Objective: To study the possibility of bone marrow mesenchymal stem cells (BMSCs) differentiation into tenocytes (TCs) under strain stimulation by co-culture of BMSCs-small intestinal submucosa (SIS) composites in vitro.

Methods: BMSCs were isolated by adherent culture from the bone marrow of 1-week-old SD rats. Inducing method of multiple differentiation and flow cytometry were applied to identify the cells.

[Experiment of oral mucosa epithelial cells cultured on small intestinal submucosa in vitro].

Objective: To explore an effective method to culture oral mucosa epithelial cells (OMECs) of canine in vitro, and to observe the biological characteristics of OMECs growing on small intestinal submucosa (SIS) in order to provide the experimental basis for epithelium tissue engineering.

Methods: The primary OMECs were cultivated with DKSFM (defined keratinocyte serum free medium) containing 6% fetal bovine serum (FBS). The morphological characteristics and the growth curve of OMECs were observed.

Mesenchymal stem cells transplantation mildly ameliorates experimental diabetic nephropathy in rats.

Background: Diabetic nephropathy is a common complication of diabetes mellitus. This study aimed to explore whether mesenchymal stem cells (MSCs) transplantation could attenuate diabetic nephropathy in experimental diabetic rats.

Methods: Sprague-Dawley rats received a single intraperitoneal injection of streptozotocin (STZ) (60 mg/kg).

Characterization of MSCs from human placental decidua basalis in hypoxia and serum deprivation.

Recently, we reported that human PDB (placental decidua basalis) is an excellent source of MSCs (mesenchymal stem cells), meanwhile, PDB-MSCs could survive under hypoxia and serum deprivation. Herein, we investigated the proliferation, clonogentic efficiency, phenotypes, metabolic activity and cytokines secretion of PDB-MSCs in hypoxia and serum deprivation. PDB-MSCs were cultured in four groups: normoxia (20% O2) and complete medium [10% FBS (foetal bovine serum)+DMEM-HG (Dulbecco's modified Eagle's medium-high glucose)], hypoxia and complete medium, normoxia and serum deprivation (0% FBS), and hypoxia and serum deprivation.

[Experimental study of repairing full-thickness articular cartilage defect with chondrocyte-sodium alginate hydrogel-SIS complex].

Objective: To explore the effect of tissue engineered cartilage reconstructed by using sodium alginate hydrogel and SIS complex as scaffold material and chondrocyte as seed cell on the repair of full-thickness articular cartilage defects.

Methods: SIS was prepared by custom-made machine and detergent-enzyme treatment. Full-thickness articular cartilage of loading surface of the humeral head and the femoral condyle obtained from 8 New Zealand white rabbits (2-3 weeks old) was used to culture chondrocytes in vitro.

The possible role of myosin light chain in myoblast proliferation.

Skeletal muscles have the potential to regenerate by activation of quiescent satellite cells, however, the molecular signature that governs satellite cells during muscle regeneration is not well defined. Myosin light chains (Myls) are sarcomere-related proteins as traditional regulator of muscle contraction. In this report, we studied the possible role of Myl in the proliferation of skeletal muscle-derived myoblasts.

[Effect of raloxifene on fracture healing of rabbits].

Objective: To detect the influence of raloxifene (RLX) on fracture healing in rabbit.

Methods: Eight healthy New Zealand white rabbits (44 females and 36 males) weighing 1.9-2.

Isolation of mesenchymal stem cells from human placental decidua basalis and resistance to hypoxia and serum deprivation.

Mesenchymal stem cells (MSCs) are the most promising seed cells for cell therapy and tissue engineering, which can be isolated from various sources of human adult tissues such as bone marrow and adipose tissue. However, cells from these tissues must be obtained through invasive procedures and sometimes the individual difference is hard to control. Hence, the search continues for an ethically conducive, easily accessible and controllable source of stem cells.

[Effects of epithelial cell conditioned medium on differentiation of BMSCs].

Objective: To investigate the feasibility of inducing canine BMSCs to differentiate into epithelial cells in vitro with epithelial cell conditioned medium (ECCM).

Methods: Five mL BMSCs were obtained from iliac spine of a healthy adult male canine with weighing 10 kg, and then isolated and cultured. The oral mucosa was harvested and cut into 4 mm x 4 mm after the submucosa tissue was eliminated; ECCM was prepared.

[An experimental study on SIS in reconstruction of tracheal defect in rabbits].

Objective: To investigate the feasibility of polypropylene mesh (PPM) coated with SIS to reconstruct tracheal defect and the efficiency of SIS in improving epithelialization of the reconstructed trachea and reducing the postoperative complications.

Methods: Twelve New Zealand white rabbits were chosen and divided randomly into 2 groups: PPM reconstruction group (n=6) and SIS-PPM reconstruction group (n=6). A tracheal full defect with a size of 1.

[Effect of osteoblast conditioned culture medium on differentiation of BMSCs].

Objective: To study the effect of rat osteoblast conditioned culture medium on the BMSCs differentiation of allogeneic rat and to find a new approach to provide seed cells for bone tissue engineering.

Methods: BMSCs and osteoblasts were harvested from 10 healthy one-week-old SD rats (male and female, weighing 20-30 g) by adherent method and enzyme digestion method respectively. Cell identification was conducted.

[Effects of hypoxia on proliferation of hBMSCs and human placental decidua basalis-MSCs].

Objective: To study the effect of hypoxia on the proliferation of hBMSCs and human placental decidua basalis-MSCs (hPDB-MSCs), and to provide the theoretical basis for discovering the new seed cells source for tissue engineering.

Methods: Density gradient centrifugation method was adopted to isolate and culture hBMSCs and hPDB-MSCs, flow cytometry (FCM) was applied to detect cell surface marker. After establishing the experimental model of CoCl2 chemical hypoxia, MTT method was applied to evaluate the proliferation of hBMSCs and hPDB-MSCs at different time points (6, 12, 24, 48, 72, 96 hours) with various CoCl2 concentration (0, 50, 75, 100, 125, 150, 175, 200 micromol/L).