Decellularization techniques have been widely used as an alternative strategy to produce matrices for organ reconstruction. This study investigated the impact of a detergent-enzymatic decellularization protocol on the extracellular matrix integrity, mechanical properties, and biocompatibility of decellularized tracheal matrices from rabbits. The tracheas of New Zealand white rabbits were decellularized using a modified detergent-enzymatic method (DEM). Antigenicity, cellularity, glycosaminoglycan content, DNA content, histoarchitecture, and mechanical properties were monitored during processing. The surface ultrastructure of the matrix was examined by scanning electron microscopy (SEM). Bioengineered and control tracheas were then implanted in major histocompatibility complex-unmatched rats (xenograft) heterotopically for 7, 15, and 30 days. Structural and functional analysis was performed after transplantation. The results showed that seven cycles of decellularization removed most of the cells and eliminated antigenicity. Histological and molecular biology analysis demonstrated that most of the cellular components and nuclear material were removed. SEM analysis revealed that the decellularized matrices retained the hierarchical structure of the native trachea, and biomechanical tests showed that decellularization did not significantly influence the mechanical properties. Seven, 15 and 30 days after implantation, decreased (p < 0.01) inflammatory reactions were observed in the xenograft models for decellularized matrices compared with control tracheas. No increases in IgM or IgG content were observed in rats that received bioengineered tracheas. In conclusion, this work suggests that seven cycles of the DEM generates a bioengineered rabbit tracheal matrix that is structurally and mechanically similar to native trachea.

To establish the procedures of genipin-linked scaffold for in situ tracheal reconstruction in a rabbit model, and to demonstrate whether stem cells can be further differentiated in the bioreactor in vivo. It will further provide an experimental and theoretical foundation for clinical application. Previously, in vitro evaluation proved the detergent-enzymatic method effectively removed stromal epithelial cells, and the number of nuclei was reduced significantly (p < 0.05). The content of type II collagen was not statistically reduced (p > 0.05). Plasmids with green fluorescence protein were transfected into 293T cells, and these cells subsequently synthesized lentivirus with green fluorescence protein that could infect other cells. After in vivo experiments, macroscopic specimen observation and hematoxylin and eosin staining comparison showed that the genipin cross-linked decellularized scaffold had low immunological rejection. Blood routine proved the progenitor cells (such as mononuclear cells) can be mobilized from the bone marrow by the growth factors, to allow their circulation into the peripheral blood. The immunohistochemistry of Type II collagen after surgery showed the expression level of bone marrow mesenchymal stem cells transplantated group was statistically higher than the autologous transplantated group (p < 0.05). The fluorescences of Bone marrow mononuclear cells (BMNCs) were traced after the specimens harvested. It successfully demonstrated that the procedures combining stem cells with the genipin cross-linked decellularized scaffold could apply to in situ airway construction. Compared to bone marrow mesenchymal stem cells, BMNCs can also be used to achieve chondrocyte differentiation; this procedure will avoid in vitro cell culture, shortening the time and economic costs.

The influences of pore sizes and surface modifications on biomechanical properties and biocompatibility (BC) of porous tracheal scaffolds (PTSs) fabricated by polycaprolactone (PCL) using 3D printing technology. The porous grafts were surface‐modified through hydrolysis, amination, and nanocrystallization treatment. The surface properties of the modified grafts were characterized by energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM). The materials were cocultured with bone marrow mesenchymal stem cells (BMSCs). The effect of different pore sizes and surface modifications on the cell proliferation behavior was evaluated by the cell counting kit‐8 (CCK‐8). Compared to native tracheas, the PTS has good biomechanical properties. A pore diameter of 200 μm is the optimum for cell adhesion, and the surface modifications successfully improved the cytotropism of the PTS. Allogeneic implantation confirmed that it largely retains its structural integrity in the host, and the immune rejection reaction of the PTS decreased significantly after the acute phase. Nano‐silicon dioxide (NSD)‐modified PTS is a promising material for tissue engineering tracheal reconstruction. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 360–370, 2019.

This study aims to investigate the expression of P-glycoprotein (PGP), glutathione S-transferase pi (GST-pi), DNA topoisomerase II (Topo-II) and lung resistance-related protein (LRP) in ovarian carcinoma, thus providing better chemotherapy choice and post-operative prognosis for ovarian carcinoma patients. A total of 80 primary ovarian carcinoma, 16 benign ovarian epithelial neoplasm, and 12 normal ovarian tissue samples were collected. Immunohistochemistry was used to detect the expression of PGP, GST-pi, Topo-II and LRP, and the results were analysed by correlation with clinicopathological parameters. Positive expression rates of PGP, GST-pi, Topo-II and LRP in patients with ovarian carcinoma (57.5%, 58.8%, 76.3% and 73.8%, respectively) were all higher than those found in normal and benign tissue (P<0.05). In clinical stages I/II vs. III/IV, the expression rates of PGP, GST-pi, Topo-II and LRP were 40.7% vs. 66% (P<0.05), 40.7% vs. 67.9% (P<0.05), 66.7% vs. 81.1% (P>0.05) and 55.6% vs. 83.0% (P<0.05), respectively. Carcinoma differentiation ranged from well to poor, and expression levels of each marker were as follows: PGP, 57.9%, 62.1% and 53.1% (P>0.05); GST-pi, 36.8%, 55.2% and 75.0% (P<0.05); Topo-II, 52.6%, 79.3% and 87.5% (P<0.05); and LRP, 84.2%, 69.0% and 71.9% (P>0.05). Ovarian carcinoma patients with PGP-, GST-pi-, Topo-II- and LRP-positive expression had a shorter median survival time than those who were negative for these markers (PGP: 36 months vs. 48 months [P=0.0017]; GST-pi: 36 months vs. 41 months [P=0.0103]; Topo-II: 37 months vs. 39 months [P=0.3811]; LRP: 37 months vs. 55 months [P=0.002]). COX regression analysis demonstrated that the clinical stage of the tumour, and the expression of PGP, GST-pi or LRP, may influence patient survival time after surgery. The relative death risk for patients with clinical stage III/IV tumours increased 9.46-fold compared to those with stage I/II tumours. The relative death risk in the PGP-, GST-pi- and LRP-positive groups increased by 2.049-, 2.452- or 2.609-fold, respectively, compared with the corresponding negative groups. PGP, GST-pi, Topo-II and LRP are all expressed in primary ovarian carcinoma, indicating the presence of multidrug resistance in this disease. Combined evaluation of PGP, GST-pi, Topo-II and LRP expression may enable better chemotherapeutic choice and provide an accurate prognosis for ovarian carcinoma patients.

Decellularization techniques have been widely used as an alternative strategy for organ reconstruction. This study investigated the mechanical, pro-angiogenic and in vivo biocompatibility properties of decellularized airway matrices cross-linked with genipin. New Zealand rabbit tracheae were decellularized and cross-linked with genipin, a naturally derived agent. The results demonstrated that, a significant (p < 0.05) increase in the secant modulus was computed for the cross-linked tracheae, compared to the decellularized samples. Angiogenic assays demonstrated that decellularized tracheal scaffolds and cross-linked tracheae treated with 1% genipin induce strong in vivo angiogenic responses (CAM analysis). Seven, 15 and 30 days after implantation, decreased (p < 0.01) inflammatory reactions were observed in the xenograft models for the genipin cross-linked tracheae matrices compared with control tracheae, and no increase in the IgM or IgG content was observed in rats. In conclusion, treatment with genipin improves the mechanical properties of decellularized airway matrices without altering the pro-angiogenic properties or eliciting an in vivo inflammatory response.