This study sought to characterize the differences between the 3D-printed and decellularized tracheal grafts, providing the basis for the synthesis of the more reasonable and effective tissue-engineered trachea. We compared the biomechanical properties and biocompatibility of the 3D-printed tracheal graft and decellularized tracheal graft in vitro and evaluated the biocompatibility, immune rejection and inflammation of the two materials through in vivo implantation experiments. Compared with the decellularized tracheal graft, the 3D-printed tracheal graft was associated with obviously higher biomechanical properties. The results demonstrated enhanced growth of BMSCs in the decellularized tracheal graft compared to the 3D-printed one when co-culture with two tracheal graft groups. Moreover, the CCK-8 assay demonstrated significant cell proliferation on the decellularized tracheal graft. Serum IgG and IgM measured in vivo by implantation testing indicated that the 3D-Printed tracheal graft exhibited the most significant inflammatory response. HE staining indicated that the inflammatory response in the 3D-printed tracheal graft consisted mainly of eosinophils, while little inflammatory cell infiltrates were observed in the decellularized tracheal graft. CD68 immunohistochemical analysis indicated that the infiltration of macrophages was not significant in both tracheal grafts. Our findings suggest that the biomechanical properties of the 3D-printed tracheal grafts are better than the decellularized tracheal grafts. Nonetheless, the decellularized tracheal graft exhibited better biocompatibility than the 3D-printed tracheal graft.

The construction of ideal tissue engineering trachea has always been a difficult problem in trachea transplantation surgery. The biological characteristics of decellularized matrix prepared by detergent-enzymatic (DEM) and 3D printing biomimetic scaffold (PTS) in vivo and in vitro were compared. In order to comprehensively evaluate its performance, we tested morphological and biomechanical characteristics of the native tracheas(Group A), DEM(Group B), and PTS(Group C). The above groups were co-cultured with bone marrow mesenchymal stem cells (BMSCs), after which cell attachment and proliferation on the scaffolds were detected. Allogeneic implantation experiments were performed to assess the in vivo biocompatibility of the studied scaffolds. Moreover, an in-situ experiment of the tracheal repair was conducted to compare the survival of every group. The biomechanical properties of PTS were significantly better than those of other scaffolds (P < .05). And they retained their structural integrity in the host compared with the other scaffolds (P < .05). Besides, significantly milder immune-rejection reactions were observed in Group C than those in Group A (P < .05). In situ experiments showed that Group C significantly a good postoperative condition compared with the other scaffold groups (P < .05). Fiberoptic bronchoscopy analysis of PTS showed a better condition in the lumen. In conclusion, PTS has excellent biomechanical properties. Although the PTS group showed lower biocompatibility than the decellularized group, it exhibited better cell attachment and proliferation. In situ transplantation results showed that PTS could be an ideal source of tissue engineering material for tracheal repair.

OBJECTIVE:To evaluate the biological properties of modified 3D printing scaffold (PTS) and applied the hybrid graft for in situ transplantation.METHODS:PTS was prepared via 3D printing and modified by Pluronic F-127. Biocompatibility of the scaffold was examined in vitro to ascertain its benefit in attachment and proliferation of bone marrow mesenchymal stem cells (BMSCs). Moreover, a hybrid trachea was constructed by combining the modified PTS with decellularized matrix. Finally, two animal models of in situ transplantation were established, one for repairing tracheal local window-shape defects and the other for tracheal segmental replacement.RESULTS:The rough surface and chemical elements of the scaffold were improved after modification by Pluronic F-127. Results of BMSCs inoculation showed that the modified scaffold was beneficial to attachment and proliferation. The epithelial cells were seen crawling on and attaching to the patch, 30 days following prothetic surgery of the local tracheal defects. Furthermore, the advantages of the modified PTS and decellularized matrix were combined to generate a hybrid graft, which was subsequently applied to a tracheal segmental replacement model.CONCLUSION:Pluronic F-127-based modification generated a PTS with excellent biocompatibility. The modified scaffold has great potential in development of future therapies for tracheal replacement and reconstruction.

Objective:To investigate the biocompatible properties of tissue-engineered rabbit trachea treated by Triton-X 100 processed method (TPM) and detergent enzymatic method (DEM) with genipin cross-linking.Methods:TPM and DEM were used to decellularize New Zealand rabbit trachea, and then genipin was used for cross-linking. The mechanical properties of each tracheal sample were measured by universal tensile testing machine. The structure of the sample was observed by scanning electron microscope. The cytotoxicity of the sample was detected by cell contact toxicity assay. Fifteen healthy adult New Zealand rabbits with no specific pathogens were divided into the native tracheal transplantation group, the genipin cross-linked TPM acellular tracheal matrix transplantation group and the genipin cross-linked DEM acellular tracheal matrix transplantation group according to the random number table, 5 animals for each group. Animals in each group were sacrificed 30 days after transplantation, and graft samples were obtained. The microstructure was observed by hematoxylin-eosin staining and CD68 molecular immunohistochemical staining.Results:Biomechanical results showed that the mechanical properties of decellularized tracheas with genipin cross-linking were similar to native tracheas. The results of scanning electron microscopy showed that the matrix of cross-linked decellularized tracheas was more dense comparing with native tracheas, and the mesh-like ultrastructure formed on the outer surface of the genipin cross-linked DEM acellular tracheal matrix was conducive to cell adhesion. The results of cell contact toxicity results showed that the genipin cross-linked decellularized tracheas treated by DEM had better biocompatibility. The results of in vivo implantation and histological staining showed that genipin cross-linked DEM acellular tracheal matrix was less immunogenic comparing with genipin cross-linked TPM acellular tracheal matrix.Conclusions:Genipin can improve the ultrastructure of decellularized tracheal matrix without causing inflammatory. The genipin cross-linked decellularized tracheas treated by DEM has better biocompatibility and lower immunogenicity, which make it suitable for the replacement of tissue engineering trachea.

目的 通过对3D打印材料与脱细胞基质的生物相容性研究,分析两种基质材料的相对优缺点,为构建更为合理的组织工程气管提供依据.方法 取2个月龄新西兰兔胫骨骨髓,采用全骨髓贴壁筛选法分离培养骨髓间充质干细胞(BMSCs).取10只6个月龄成年新西兰兔气管,修剪至每段1.5 cm,随机分为原生气管组(A1,n=5),剥离气管外表面疏松结缔组织;脱细胞气管组(B1,n=5)采用脱氧胆酸钠联合酶法脱细胞7个周期获取;利用3D打印技术制备聚己内酯(PCL)管型支架,并行纳米二氧化硅修饰处理(C1,n=5).测量各组气管基本形态及生物力学性能.取第4代BMSCs制备细胞-支架复合物,培养48 h时行Giemsa染色观察材料周围的细胞活性;CCK-8及扫描电子显微镜(SEM)检测细胞增值及黏附性能.取15只6个月龄成年新西兰兔,随机分成原生组(A2,n=5)、脱细胞气管组(B2,n=5)和PCL气管组(C2,n=5),分别于颈背部皮下皮囊埋植3组支架.术后动态分析血清免疫球蛋白IgM和IgG变化,术后30 d行HE染色观察以及免疫组化评估支架炎症反应情况.结果 3组气管在宏观形态上基本一致,生物力学性能C1要优于B1组.Giemsa染色:B1组周围细胞生长情况优于C1组;SEM检测:细胞在脱细胞及PCL支架上均增殖附着良好;CCK-8:脱细胞气管支架组细胞增殖情况优于其他两组;体内埋植实验测血清IgG、IGM提示C2组炎症反应在急性期最为明显;术后可见A2、B2组表面结缔组织包裹明显,而C2组结构保持相对完整,HE染色提示A.组的炎症细胞以单核细胞、浆细胞等浸润为主,C2组炎症的反应以嗜酸性粒细胞浸润为主,而B2组炎症细胞浸润最少;免疫组化CD68染色提示B2组、C2组巨噬细胞浸润均不明显.结论 3D打印材料的生物力学性能较脱细胞材料更好,但脱细胞气管基质材料生物相容性更优.

Background: With the development of novel surgical techniques and instruments over the recent years, more and more surgeons consider single-port video-assisted thoracoscopic surgery (VATS) as a feasible option. However, whether single-port thoracoscopic surgery has more potential advantages than two-port thoracoscopic surgery for non-small cell lung cancer remains unknown. We conducted this systematic review and meta-analysis to compare the perioperative efficacy between single-port and two-port VATS anatomical lung resection for non-small cell lung cancer (NSCLC). Methods: Eleven studies were identified from the databases of The Cochrane Library, PubMed, Embase, Web of science, and China Biology Medicine disc (CBMdisc). Prospective studies and retrospective studies that evaluated the perioperative efficacy of single-port VATS compared with two-port VATS were analyzed. We used 95% confidence intervals (CIs) to calculate the odds ratio (OR), and the weight mean difference (WMD). Results: A total of 11 studies (3 prospective studies and 8 retrospective studies), including 1,592 patients, were included. We found that the duration of the operation in single-port VATS anatomical lung resection for NSCLC was shorter (P=0.02). Also, the bleeding volume amount was lower (P=0.01), the length of postoperative drainage was shorter (P<0.00001), the amount of postoperative hospital stay was lower (P<0.0001), and the visual analogue score 24 and 72 h after operation time was lower (P<0.0001, P<0.00001). However, the number of lymph nodes retrieved (P=0.92) and the rates of complications (P=0.15) had no statistical differences between the two groups. Conclusions: These studies show that single-port VATS anatomical lung resection has certain advantages in the treatment of NSCLC compared with two-port VATS. It may be an alternative option for surgeons.

Objective To prepare 3D printed porous tracheal graft fabricated by PCL and to select the appropriate pore size and surface modification techniques,in order to explore its effect on cell behavior.Methods The PCL porous tracheal graft was prepared by 3D printing technology and biomechanical properties of the graft were measured by means of longitudinal tension,radial compression and three-point bending test.The porous grafts were surface-modified through hydrolysis,amination and nanocrystallization treatment and then characterized by energy dispersive spectroscopy(EDS).The effect of different pore sizes and surface modifications on the cell proliferation behavior was evaluated by CCK-8 and scanning electron microscopy (SEM).Results The 3 D printed porous tracheal graft had similar morphology with the native tracheas(P ＞ 0.05) and better biomechanical properties(P ＜0.05).It was more suitable for cell adhesion and proliferation when the pore size is 200 μm (P ＜ 0.05).Compared to hydrolysis and amination,nanocrystallization treatment successfully improved the cytotropism of the 3D printed tracheal graft(P ＜ 0.05).Conclusion 3 D printed porous tracheal graft shows favorable biomechanical properties.The appropriate pore size of the 3D printed porous tracheal graft is 200 μm and the appropriate surface modification techniques is nanocrystallization.

In this paper, we reported a simple one-step synthesis of highly-branched gold nanostructures (HGNs) in high yields. The reduction of HAuCl4 was accomplished by dopamine hydrochloride in the reaction system. By varying the amount of dopamine hydrochloride, HAuCl4 and the reaction temperature, we managed to tune the size of the HGNs from 200 to 600 nm. Systematic analysis revealed that the optical properties and surface-enhanced Raman scattering (SERS) activities of the HGNs were highly dependent on their morphology and size. In terms of their SERS activities, it was found that the HGNs synthesized at 60 °C with 2.0 mL dopamine hydrochloride (53 mM), 0.4 mL HAuCl4 (50 mM) exhibited the largest SERS enhancement. When the HGNs were assembled onto the silicon wafers, outstanding SERS efficiency was obtained with a detection limit of 5×10-10 M of 4-mercaptobenzoic acid (4-MBA) and the analytical enhancement factor (AEF) was calculated to be 7×107. Besides, the 3-aminopropyltriethoxysilane (APTES)-functionalized substrates with the HGNs displayed remarkable signal reproducibility with relative standard deviation (RSD) of 3.57%. All these results demonstrated that the SERS-active substrates held great promise to be applied in trace-level molecule detection in the future.

The goals of our study were to evaluate the biomechanical properties and cellular biocompatibility of 3D printed tracheal graft fabricated by polycaprolactone (PCL). Compared with native tracheal patch, there was a significant increase in maximum stress and elastic modulus for 3DP tracheal graft (p < 0.05). BMSCs were co-cultured under four different conditions to investigate cytotoxicity of the graft: (1) co-cultured with normal culture medium, as blank control; (2) co-cultured with perfluoropropylene, as negative control; (3) co-cultured with 3DP tracheal graft; and (4) co-cultured with polyvinyl chloride, as positive control. Moreover, the results of SRB assay showed that compared with blank and negative control group, there was no significant difference in the cell proliferation of 3DP tracheal graft group for 21 days (p > 0.05). These results revealed that 3DP tracheal graft in our study has favorable cellular biocompatibility and biomechanical properties, and, therefore, will be a promising alternative for tissue-engineered trachea.