【Abstract】 Objective To develop a novel cartilage acellular matrix (CACM) scaffold and to investigate its performance for cartilage tissue engineering. Methods Human cartilage microfilaments about 100 nm-5 μm were prepared after pulverization and gradient centrifugation and made into 3% suspension after acellularization treatment. After placing the suspension into moulds, 3-D porous CACM scaffolds were fabricated using a simple freeze-drying method. The scaffolds were cross-l inked by exposure to ultraviolet radiation and immersion in a carbodiimide solution 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N-hydroxysucinimide. The scaffolds were investigated by histological staining, SEM observation and porosity measurement, water absorption rate analysis. MTT test was also done to assess cytotoxicity of the scaffolds. After induced by conditioned medium including TGF-β1, canine BMSCs were seeded into the scaffold. Cell prol iferation and differentiation were analyzed using inverted microscope and SEM. Results The histological staining showed that there are no chondrocytefragments in the scaffolds and that toluidine blue, safranin O and anti-collagen II immunohistochemistry staining werepositive. The novel 3-D porous CACM scaffold had good pore interconnectivity with pore diameter (155 ± 34) μm, 91.3% ± 2.0% porosity and 2 451% ± 155% water absorption rate. The intrinsic cytotoxicity assessment of novel scaffolds using MTT test showed that the scaffolds had no cytotoxic effect on BMSCs. Inverted microscope showed that most of the cells attached to the scaffold. SEM micrographs indicated that cells covered the scaffolds uniformly and majority of the cells showed the round or ell iptic morphology with much matrix secretion. Conclusion The 3-D porous CACM scaffold reserved most of extracellular matrix after thoroughly decellularization, has good pore diameter and porosity, non-toxicity and good biocompatibil ity, which make it a suitable candidate as an alternative cell-carrier for cartilage tissue engineering.
Objective To produce a decellularized cartilage matrix (DCM) and investigate its possibil ity to be used as a scaffold for tissue engineering. Methods Fresh bovine articular cartilage from knee joints was sl iced, freeze-dried and freeze-ground into fine powder, and then was treated sequentially with Trypsin, Triton X-100 and hypotonic solution for decellularization. The decellularized matrix was freeze-dried for shaping and cross-l inked by UV radiation. Histological, immunohistological, SEM, porosity assays and biomechanical assays were used to characterize the DCM. BMSCs were isolated from rabbit bone marrow aspirate and cultured in DCM extraction medium of different concentration (100%, 10% and 1%) for 0, 24, 48 and 72 hours, respectively, to detect the release rate of the lactate dehydrogenase (LDH). The DMEM medium (5% FBS) served as the control. Biocompatibil ity was evaluated using BMSCs (1 × 107/mL) cultured with DCM. Results The DCM showed white spongy appearances, and histological analysis showed that the material was constructed by cartilage particles without any cells or cell fragments left in the matrix. Immunohistology staining and alcian blue staining showed that DCM retained the collagen and glycosaminoglycan components of cartilaginous matrix. SEM scanning showed that DCM had a porous spongy-l ike structure with the aperture ranging 30-150 μm .The porosity assay showed that the average porosity was 89.37% and the average aperture was 90.8 μm. The mechanical assay showed that there was no difference for the compress module before and after the decellularization process, which was (17.91 ± 0.98) MPa and (15.12 ± 0.77) MPa, respectively (P gt; 0.05), but were both statistical different from normal articular cartilage [(26.30 ± 1.98) MPa, P lt; 0.05]. The LDH release rate in the DCM extraction medium of different concentration was not significantly different from that in the normal DMEM medium (P gt; 0.05). The cell adhesion test showed BMSCs grew well on DCM without any signs of growth inhibition. Conclusion Articular cartilage can be decellularized and fabricated into a scaffold which retains the major components of cartilaginous matrix. DCM has goodbiochemical, biophysical characteristics and good biocompatibil ity with cultured BMSCs and may be used as a novel scaffold for tissue engineering studies.
Lung transplantation is the only treatment for patients with end-stage lung diseases. And this field is also a research hotspot in the international field at presen. Relevant researches not only promote the progress and development of lung transplantation, but also improve the life quality of patients after transplantation. With the development of lung transplantation technology, the guidelines for identifying candidates are constantly being revised, and the source of donor lungs has always been an urgent problem for all transplantation centers. The standardized management during transplantation period involves anesthesia induction, intraoperative fluid management, airway management, management of important operative steps and postoperative pain management. Extracorporeal life support (ECLS) includes cardiopulmonary bypass (CPB) and extracorporeal membrane oxygenation (ECMO). With the progress and development of ECLS technology, the advantages of ECMO as a bridge for lung transplantation, intraoperative and postoperative circulatory support are becoming more and more prominent, enabling recipient patients to successfully pass the period of lung transplantation. Although lung transplantation in basic science and clinical researches has got a lot of progress, to improve the survival rate after transplantation, we must overcome many challenges including how to successfully perform lung transplantation, expand lung donor library, induce tolerance, and prevent complications after transplantation, primary graft dysfunction (PGD), cell and antibody mediated rejection and infection.
As an extracorporeal life support technology, veno-venous extracorporeal membrane oxygenation (VV-ECMO) has been demonstrated its role in the treatment of patients with severe respiratory failure. Its main advantages include the ability to maintain adequate oxygenation and remove excess CO2, increase oxygen delivery, improve tissue perfusion and metabolism, and implement lung protection strategies. Clinicians should accurately assess and identify the patient's condition, timely and accurately carry out VV-ECMO operation and management. This article will review the patient selection, cannulation strategy, anticoagulation, clinical management and weaning involved in the application of VV-ECMO.
Cardiogenic shock (CS) describes a physiological state of end-organ hypoperfusion characterized by reduced cardiac output in the presence of adequate intravascular volume. Mortality still remains exceptionally high. Veno-arterial extracorporeal membrane oxygenation (VA ECMO) has become the preferred device for short-term hemodynamic support in patients with CS. ECMO provides the highest cardiac output, complete cardiopulmonary support. In addition, the device has portable characteristics, more familiar to medical personnel. VA ECMO provides cardiopulmonary support for patients in profound CS as a bridge to myocardial recovery. This review provides an overview of VA ECMO in salvage of CS, emphasizing the indications, management and further direction.
Objective To systematically review the correlation of activated partial thromboplastin time (APTT) and prognosis after ECMO treatment. Methods The PubMed, EMbase, MEDLINE, CNKI, WanFang Data and VIP databases were electronically searched to collect studies on the correlation of APTT and prognosis after ECMO treatment from database inception to April 11th, 2022. Two researchers independently screened the literature, extracted data, and evaluated the risk of bias of the included studies. Meta-analysis was then performed using RevMan 5.4 software. Results A total of 22 studies, involving 2 913 patients were included. The level of APTT in the bleeding group was higher than that in the non-bleeding group during ECMO support treatment (MD=10.34, 95%CI 1.32 to 19.37, P=0.02). The APTT level in the thrombus group was lower than that in the non-thrombus group (MD=−3.58, 95%CI −5.89 to −1.27, P=0.002). The level of APTT in the death group was significantly higher than that in the survival group (MD=8.97, 95%CI 5.89 to 12.06, P<0.00001). Conclusion The APTT level of ECMO patients is closely related to the prognosis of bleeding, thrombosis and death. Due to the limited quantity and quality of the included studies, the above conclusion needs to be verified by more high-quality studies.