Objective To compare the attachment and growth of fibroblasts on the different porcine accellular dermal matrix (ADM) so as to find the suitable scaffold for tissue engineering skin. Methods Fibroblasts (5×10 5) were seeded on 4 kinds of ADMs which were crosslinked with glutaraldehyde, uncrosslinked, crosslinked with glutaraldehyde and removed basement membrane, corsslinked with glutaraldehyde and then meshed. The same density fibroblasts were seeded on petri dish as a control. Cell count was done on the 1st, 3rd, 5th days after seeding. The at tachment of fibroblasts on ADM sw as observed by HE staining. Results The grow th and at tachment of fibroblasts on cro sslinked and non2meshed ADM increasedmarkedly w hen compared w ith the o thers. There w as no obvious difference betw een the group s of w ith o r w ithout basement membrane. Conclus ion The above results indicate that non2meshed and co rsslinked w ith glutaraldehyde ADM ismo re suitable fo r the at tachment and grow th of fibroblasts than the o thers and that the modified ADM can be used fo r the scaffo ld of t issue engineering skin.
Objective Extracellular matrix is one of the focus researches of the adi pose tissue engineering. To investigate the appropriate method to prepare the porcine skeletal muscle acellular matrix and to evaluate the biocompatibility of the matrix. Methods The fresh skeletal muscle tissues were harvested from healthy adult porcine and were sl iced into2-3 mm thick sheets, which were treated by hypotonic-detergent method to remove the cells from the tissue. The matrix was then examined by histology, immunohistochemistry, and scanning electron microscopy. The toxic effects of the matrix were tested by MTT. Human adi pose-derived stem cells (hADSCs) were isolated from adi pose tissue donated by patients with breast cancer, and identified by morphology, flow cytometry, and differentiation abil ity. Then, hADSCs of passage 3 were seeded into the skeletal muscle acellular matrix, and cultured in the medium. The cellular behavior was assessed by calcein-AM (CA) and propidium iodide (PI) staining at 1st, 3rd, 5th, and 7th days after culturing. Results Histology, immunohistochemistry, and scanning electron microscopy showed that the muscle fibers were removed completely with the basement membrane structure; a large number of collagenous matrix presented as regular network, porous-like structure. The cytotoxicity score of the matrix was grade 1, which meant that the matrix had good cytocompatibil ity. The CA and PI staining showed the seeded hADSCs had the potential of spread and prol iferation on the matrix. Conclusion Porcine skeletal muscle acellular matrix has good biocompatibility and a potential to be used as an ideal biomaterial scaffold for adi pose tissue engineering.
Objective To develop a new small-caliber vascular xenograft and evaluate the feasibility of xenogenic artery for coronary artery bypass grafting. Methods Canine carotid arteries were decellularized by detergent and enzymatic extraction. All decellularized xenografts were randomly divided into two groups. Heparin-linked group （n=24）： grafts were then covalently linked with heparin. Non-heparin-linked group （n=24）： as control. Xenografts in two groups were implanted in rabbits＇ left and right carotid artery respectively as bypass grafts. Graft patency was checked by ultrasonography after 3 weeks, 3 and 6 months. Grafts were harvested after 3 and 6 months. Microscopic observation and immunohistochemical staining were performed. Results All the cells were removed while the extracellular matrix were well preserved observed. Heparin was successfully linked to the grafts through their whole thickness. There was no obstruction at both sides after implantation of the grafts, while less thrombus was found in the decellularized heparin-linked grafts than in the other side. Smooth muscle cells densely populated the graft wall and endothelial cells covered the lumen at 3 months after implantation. Conclusion Canine common carotid artery treated by detergent and enzymatic extraction and heparin linkage may be a new small-caliber vascular xenograft for coronary artery bypass grafting.
Objective To choose the best procedure on preparation of acellularbovine pericardium (ABP) guided bone regeneration (GBR) material. Methods The BP was decellularized with 0.25% Trypsin+0.5% Triton X-100. The acellular bovine pericardiums (ABPs) were treated with phosphatebuffered saline(PBS) (group A), 95% glycerol (group B), EDAC (group C), and EDAC and 95% glycerol (group D) respectively. The treated ABPs were implanted subcutaneously in the back of SD rats respectively at random and no material was implanted as control. Seven rats were sacrificed at 2 weeks, twelve at 4 weeks, twelve at 8 weeks, seven at 16 weeks. Local reaction was studied grossly. The amount of antigen presenting cell (APC) and the percentage of ABP degeneration were reckoned by images analysis system. Results The ABPs were replaced by fibroblasts completely in group A at 8 weeks， in group C at 16 weeks, but only less than 50% till 16 weeks in groups B and D. In all groups, the depth of surrounding fibres attenuated timedependingly. The APC amount of the groups B and D was higher than that of the control group, and the ABP of the groups B and D degraded partly at 16 weeks. Conclusion The ABP treated with EDAC can be replaced by the surrounding tissues and has good biocompatibility.
ObjectiveTo review the recent research progress of acellular fish skin as a tissue engineered scaffold, and to analyze the feasibility and risk management in clinical application. MethodsThe research and development, application status of acellular fish skin as a tissue engineered scaffold were comprehensively analyzed, and then several key points were put forward. ResultsAcellular fish skin has a huge potential in clinical practice as novel acellular extracellular matrix, but there have been no related research reports up to now in China. As an emerging point of translational medicine, investigation of acellular fish skin is mainly focused on artificial skin, surgical patch, and wound dressings. ConclusionDevelopment of acellular fish skin-based new products is concerned to be clinical feasible and necessary, but a lot of applied basic researches should be carried out.
Objective To investigate the effect of machine-enzyme digestion method on the residual quantity of small intestinal submucosa (SIS) cell and the content of growth factors. Methods Fresh jejunum of pig within 4 hours after harvesting was prepared into SIS after machine digestion (removing placenta percreta, mucosa, and muscular layer), degrease,trypsinization, abstergent processing, and freeze drying. Samples were kept after every preparation step serving as groups A, B, C, D, and E, respectively (n=4 per group). And the fresh jejunum served as control group (group F, n=4). The histological alteration in each preparation process was reviewed with HE staining and scanning electron microscope (SEM). Nest-polymerase chain reaction (PCR) was used to determine the content of death associated protein 12 (DAP12), and enzyme-linked immunosorbent assay (ELISA) was appl ied to detect the content of vascular endothel ial growth factor (VEGF), basic fibroblast growth factor (bFGF), transforming growth factor β (TGF-β), tumor necrosis factor α (TNF-α). Results HE staining and SEM observation showed that there were residual cells in groups A and B, and there were no residual cells in groups C, D, and E. Nest-PCR test revealed the occurrence of DAP12 in each group. The contents of DAP12 in groups A, B, C, D, E, and F were (18.01 ± 9.53), (11.87 ± 2.35), (0.59 ± 0.27), (0.29 ± 0.05), (0.19 ± 0.04), and (183.50 ± 120.13) copy × 106/cm2. The content of DAP12 in group F was significant higher than that of other groups (P lt; 0.05), groups A and B was higher than groups C, D, and E (P lt; 0.05), there were significantdifferences among groups C, D, and E (P lt; 0.05), and there was no significant difference between groups A and B (P gt; 0.05). The ELISA test showed the content of VEGF, bFGF, TGF-β, and TNF-α in group A was significantly higher than that of groups B, C, D, and E (P lt; 0.05), and there was no significant difference among groups B, C, D, and E (P gt; 0.05). Conclusion SIS prepared by simple mechanical method has more residual cells, while the machine-enzyme digestion method can effectively remove the cells and significantly reduce the DAP12 content. This approach can not obviously reduce the growth factor content in SIS.
Objective To evaluate the efficacy and safety of acellular dermal matrix (ADM) in preventing Frey syndrome.Methods Studies of acellular dermal matrix in preventing Frey syndrome were searched in The Cochrane Library (Issue 1, 2010), MEDLINE, EMbase, SIGLE, GreyNet, NTIS, CBMdisc, VIP, CNKI and WANFANG DATA from 1995 to 2010. All the studies were selected, extracted and evaluated by four reviewers independently, and meta-analyses were performed with RevMan 5.0.0 software. Results A total of 15 studies involving 472 participants were included in the review. The studies showed that implantation of the ADM was able to efficiently reduce the incidence of Frey syndrome, and the difference in both subjective and objective was significant between the two groups after the therapy (RR=0.11, 95%CI 0.06 to 0.18, Plt;0.01; RR=0.14, 95%CI 0.10 to 0.19, Plt;0.01). The rate of temporary facial nerve paralysis was lower than that of the control group but the difference was not significant (OR=0.78, 95%CI 0.37 to 1.66, P=0.53). The incidens of both seroma and mucocele were higher than that of the control group but the difference was not significant(OR=2.63, 95%CI 0.09 to 79.25, P=0.58) and they could be alleviated by placing drainage tube and partial pressure bandage. The incidence rate of salivary fistula was lower than that of the control group and the difference was significant (OR=0.24, 95%CI 0.08 to 0.69, P=0.009). Conclusion The result of this system review shows that, the ADM can effectively and safely reduce the incidence of Frey syndrome. To perform preoperative hypersensitivity check for iodine or iodophors, to conduct rapid frozen section for defining the character of tumor, to fix the ADM stably, to place vacuum-drainage and to make partial pressure bandage are suggested.
Objective To investigate the biological and biomechanical characteristics of acellular porcine aortic valve with dye mediated photo oxidation so that a new and better bioprosthetic valve materials can be obtained. Methods Thirty porcine aortic valves were divided into three groups with random number table. Acellular valves (n=10) were stabilized by dye mediated photo oxidation in dye mediated photo oxidation group; acellular valves (n=10) were stabilized by glutaraldehyde in glutaraldehyde group; and acellular valves (n=10) were acellularized only in acellular valves group. Thickness, appearance, histology, water content, shrinkage temperature, breaking strength and soluble protein level of acellular porcine aortic in three groups were tested respectively. Results There were light blue, soft, flexible and unshrinking valves in dye mediated photo oxidation group. Compared to valves in glutaraldehyde group, valves in dye mediated photo oxidation group had lighter thickness（0.26±0.09mm vs. 0.38±0.08mm，Plt;0.05）, more water content（86.30%±4.03% vs. 71.10%±3.23%，Plt;0.05）, and lower shrinkage temperature （76.30±0.70℃ vs. 87.70±0.30℃，Plt;0.05）; while these indexes had no statistically significant differences compared to those in acellular valves group. At the same time, compared to valves in acellular valves group, valves in dye mediated photo oxidation group had more breaking strength（17.33±2.65 mPa vs. 9.11±0.95 mPa，Plt;0.05） and lower soluble protein level（0.039%±0.013% vs. 0.107%±0.024%，Plt;0.05）; while these indexes had no statistically significant differences compared to those in glutaraldehyde group. Conclusion Acellular porcine aortic valve stabilized by dye mediated photo oxidation has nice biological and biomechanical characteristics.
ObjectiveTo systematically review the efficacy of acellular dermal matrix (ADM) and subepithelial connective tissue flap (sCTG) on patients with gingival recession (GR).MethodsPubMed, EMbase, The Cochrane Library, CNKI, WanFang Data and VIP databases were electronically searched to collect randomized controlled trials (RCTs) about the efficacy of ADM and sCTG on patients with GR from inception to August 11st, 2019. Two reviewers indepeudently screened literature, extracted data and assessed the risk of bias of included studies, and then meta-analysis was performed by using RevMan 5.3 software and Stata 12.1 software.ResultsA total of 9 RCTs were included. The results of meta-analysis showed that: there were no significant differences in probing depth (PD) (MD3m=?0.04, 95%CI ?0.18 to 0.11, P=0.63; MD6m=?0.01, 95%CI ?0.13 to 0.12, P=0.90) and GR degree (MD3m=?0.10, 95%CI ?0.37 to 0.18, P=0.48; MD6m=?0.02, 95%CI ?0.33 to 0.29, P=0.89) in 3 and 6 months after operative between two groups. But the clinical attachment loss (CAL) in 3 months after operation (MD=0.33, 95%CI 0.00 to 0.66, P=0.05) and width of keratinized tissue (KTW) in 6 months after operation (MD=?0.48, 95%CI ?0.76 to ?0.20, P=0.000 7) of sCTG group were superior to ADM group, the differences were statistically significant.ConclusionCurrent evidence shows that there are no differences in PD and GR degree in 3 months and 6 months after operation between ADM and sCTG group. But the CAL in 3 months after operation and KTW in 6 months after operation of sCTG group is superior to ADM group. Due to limited quality and quantity of the included studies, more high-quality studies are needed to verify above conclusion.
In the past fifty more years, many research results have been achieved in the field of artificial esophagus which has been a major subject of surgical study on esophagus. Unfortunately,a very satisfactory artificial esophagus has not been found due to lack of proper artificial materials and problems of postoperative complications which results in great hindrance to applying them to clinical purpose. The current research focuses on artificial esophaguses constructed with acellular matrix as well as constructed through tissue engineering,furthermore,how to prevent and cure postoperative complications is still the main difficulty. This paper gives an overview of the recent study results,points in dispute, present status of research and the recent advances, and an overview to the future of artificial esophagus.