International Journal of Artificial Organs最新文献

Liver transplantation is the only definitive treatment for end-stage liver disease and its availability is restricted by organ donor shortages. The development of liver bioengineering provides the probability to create a functional alternative to reduce the gap in organ demand and supply. Decellularized liver scaffolds have been widely applied in bioengineering because they can mimic the native liver microenvironment and retain extracellular matrix (ECM) components. Multiple approaches including chemical, physical and biological methods have been developed for liver decellularization in current studies, but a full set of unified criteria has not yet been established. Each method has its advantages and drawbacks that influence the microstructure and ligand landscape of decellularized liver scaffolds. Optimizing a decellularization method to eliminate cell material while retaining as much of the ECM intact as possible is therefore important for biological scaffold applications. Furthermore, crosslinking strategies can improve the biological performance of scaffolds, including reinforcing biomechanics, delaying degradation in vivo and reducing immune rejection, which can better promote the integration of re-cellularized scaffolds with host tissue and influence the reconstruction process. In this review, we aim to present the different liver decellularization techniques, the crosslinking methods to improve scaffold characteristics with crosslinking and the preparation of soluble ECM.

Background: The hydrodynamic suspension structure design of the axial blood pump impeller can avoid the problems associated with using mechanical bearings. However, the particular impeller structure will impact the hydraulic performance and hemolysis of the blood pump.

Method: This article combines computational fluid dynamics (CFD) with the Lagrange particle tracking method, aiming to improve the blood pump's hydraulic and hemolysis performance. It analyzes the flow characteristics and hemolysis performance inside the pump. It optimizes the taper of the impeller hub, the number of blades, and the inclination angle of the circumferential groove at the top of the blade.

Results: Under certain rotational speed conditions, an increase in the taper of the impeller hub or the number of blades can increase the pumping pressure of a blood pump, but an increase in the number of blades will reduce the flow rate. The design of circumferential grooves at the top of the blade can increase the pumping pressure to a certain extent, with little impact on the hemolysis performance. The impeller structure is optimized based on the estimated hemolysis of each impeller model blood pump. It could be seen that when the pump blood pressure and flow rate were reached, the optimized impeller speed was reduced by 11.4%, and the estimated hemolysis value was reduced by 10.5%.

Conclusion: In this paper, the rotor impeller structure of the blood pump was optimized to improve the hydraulic and hemolytic performance effectively, which can provide a reference for the related research of the axial flow blood pump using hydraulic suspension.

Critically ill septic patients present variable clinical trajectories, with some succumbing to hyperinflammatory responses while others develop a chronic critical illness, characterized by a prolonged low-grade inflammation, muscle atrophy, and mechanical ventilation dependency and often develop secondary infections often caused by from low-virulence microorganisms or reactivated latent viruses. The Seraph-100^® hemoperfusion cartridge takes advantage from heparin-coated ultra-high molecular weight polyethylene microbeads mimicking pathogen-binding cell receptors and can adsorb both pathogens and damage-associated molecular patterns released by injured tissues. We describe two chronic critically ill patients who developed secondary viral bloodstream infections successfully treated with this device.

We conducted a prospective, open-labeled, clinical trial, with a two-by-two factorial design, of argon cold plasma application and two different types of driveline positioning for the prevention of driveline infection (DLI) in 80 patients with a left ventricular assist device (LVAD) implant. Here, we present the results of intracorporeal loop positioning (n = 40) versus no intracorporeal loop positioning (n = 40). Patients were followed up for 1 year. According to the Driveline Expert STagINg and carE grading (DESTINE) system, a DLI was considered in case of a stage 2 or higher graded infection. During follow-up, 29 (36%) patients experienced a DLI, 16 in the group with intracorporeal loop positioning and 13 in the group with no intracorporeal loop positioning. Kaplan-Meier estimates of freedom from DLI showed no statistically significant difference between study groups during follow-up (p = 0.33). In detail, 30-day freedom from DLI was for the groups with and without intracorporeal loop positioning 92 and 92%, respectively, and 1-year freedom from DLI was 51 and 62%, respectively. In conclusion, this controlled clinical trial was unable to show a statistically significant difference in freedom from DLI during one year of follow-up in groups with or without intracorporeal loop positioning. However, larger trials have to confirm these results.

Objective: To investigate the effectiveness and safety of regional citrate-anticoagulated (RCA) plasma exchange (PE) and whether citrate-related metabolic disorders can be improved by sequential RCA continuous renal replacement therapy (CRRT).

Methods: This retrospective, single-center observational study included 79 critically ill children requiring PE followed by CRRT (June 2018 to June 2021) at the Pediatric Intensive Care Unit of Hunan Children's Hospital, China. Patients were divided into the RCA-PE (n = 30) and systemic heparin anticoagulation (SHA-PE) (n = 49) groups. Filter level comparison post-PE assessed RCA-PE efficacy, and metabolic changes occurring pre- and post-PE and CRRT were used to evaluate the effect of CRRT on RCA-based anticoagulation safety.

Results: The RCA-PE group had a better overall filter performance than the SHA-PE group. Two hours after PE, pH and HCO₃^- levels increased more significantly for the RCA-PE than the SHA-PE group. The RCA-PE incidence of metabolic alkalosis was 48.3%, higher by 4.2% (p < 0.001) compared to the SHA-PE group. In the RCA-PE group, pH and HCO₃^- decreased significantly 4 h after CRRT; the metabolic alkalosis caused by RCA-PE decreased to 13.8% (p = 0.005). No significant difference in pH, HCO₃^-, and metabolic alkalosis incidence was observed between the two groups 4 h after CRRT.

Conclusions: The overall filtration performance of RCA-PE is superior to that of SHA-PE followed by CRRT. The metabolic complications associated with RCA-PE are mainly metabolic alkalosis that can be improved by using CRRT after RCA-PE and this is a better alternative for anticoagulation during PE in critically ill children.

Bone defects or bone discontinuities caused by trauma, infection, tumours and other diseases have led to an increasing demand for bone grafts and biomaterials. Autologous bone grafts, bone grafts with vascular tips, anastomosed vascular bone grafts and autologous bone marrow components are all commonly used in clinical practice, while oversized bone defects require the use of bone tissue engineering-related biomaterials to repair bone defects and promote bone regeneration. Currently, inorganic components such as polysaccharides and bioceramics, as well as a variety of bioactive proteins, metal ions and stem cells can be loaded into hydrogels or 3D printed scaffold materials to achieve better therapeutic results. In this review, we provide an overview of the types of materials, applications, potential mechanisms and current developments in the repair of bone defects.

Background: Congenital pseudoarthrosis of the tibia (CPT) is an uncommon disease associated with failure to achieve bone union and recurrent fractures. There is evidence showing that CPT is associated with decreased osteogenesis. Based on the capacity of mesenchymal stromal cells (MSCs) to induce osteogenesis, we develop an osteogenic organoid (OstO) constituted by these cells, and other components of the bone niche, for inducing bone formation in a child diagnosed with CPT.

Aim: To evaluate the capacity of an OstO to induce bone formation in a patient with CPT.

Methods: The OstO was fabricated with allogeneic bone marrow MSCs from a healthy donor, collagen microbeads (CM) and PRP clot. The CM and PRP function as extracellular matrix and scaffolds for MSC. The OstO was placed at the site of non-union. Internal and external fixation was placed in the tibia. Radiological evaluation was performed after MSCs transplantation.

Results: After 4 months of MSCs transplantation, radiographic imaging showed evidence of osteogenesis at the site of CPT lesion. The tibia showed bone consolidation and complete healing of the non-union CPT lesion after 6 months. Functional improvement was observed after 1 year of MSC transplantation.

Conclusions: The OstO is a bone-like niche which promote osteogenesis in patients with failure in bone formation, such as CPT. To our knowledge, these results provide the first evidence showing CPT healing induced by an OstO constituted by allogeneic MSCs. Future studies incorporating a larger number of patients may confirm these results.

Objective: To systematically evaluate the clinical efficacy of pulmonary rehabilitation in patients with mechanical ventilation in an intensive care unit (ICU).

Methods: Relevant studies were identified in the PubMed, Web of Science, National Library of Medicine, China National Knowledge Infrastructure and Wanfang databases. A meta-analysis was performed after screening based on the inclusion and exclusion criteria, data extraction and literature quality evaluation.

Results: In total, 19 studies involving 2181 participants were included. The results of the meta-analysis revealed that compared with patients with conventional rehabilitation measures, patients with pulmonary rehabilitation measures had a higher offline success rate (relative risk (RR) = 1.16; 95% confidence interval (CI): 1.09, 1.24; p < 0.00001) and higher arterial oxygen partial pressure levels (mean difference (MD) = 8.96; 95%CI: 5.98, 11.94; p < 0.0001) and these measures significantly shortened the duration of mechanical ventilation (standardised MD (SMD) = -1.08; 95%CI: -1.58, -0.59; p < 0.0001) and ICU stay (SMD = -1.41; 95%CI: -1.94, -0.88; p < 0.0001). Aspiration significantly reduced the incidence of ventilator-associated pneumonia (RR = 0.35; 95%CI: 0.24, 0.51; p < 0.00001) and deep vein thrombosis (RR = 0.32; 95%CI: 0.13, 0.76; p = 0.01) in ICU patients with mechanical ventilation.

Conclusion: Pulmonary rehabilitation measures can improve the success rate of weaning from mechanical ventilation in ICU patients, shorten the time of mechanical ventilation and ICU hospitalisation and reduce the incidence of related adverse reactions, but the impact on mortality requires further study.

Objectives: To manage the mandibular traumas, for the expression of the complex anatomy or pathology in education of health sciences related branches, a model of the traumatized mandible is indispensable. For these, different 3D-print-technologies can be used. The aim of this study is, to measure how close these 3D-printed-models are to human-mandible (trueness) and the effectiveness of CT and CBCT at this point.

Study design: One-dry-human-mandible and 10-models manufactured by five different 3D-printers in four different-kinds of additive-manufacturing technology (Fused-Deposition-Modeling (FDM), Stereolithography (SLA), Binder-jetting (BJ), Polyjet (PJ)) were used, five-anatomic-landmarks and eight-distances were measured and evaluated. Mandible's data were constructed based on DICOM-3.0 data from CBCT and CT scans. Images were opened in MIMICS (software-program).

Results: Study compared the devices that produced models with the same dry human-mandible. It was seen that the model with the highest margin of error (132.5 mm) was manufactured by Fused-deposition-modeling device using CT-data. In terms of distance to real-data, the model with the lowest error was generated by Binder-Jetting (ZCorp) with CBCT-data. Models produced with CBCT-data are closer to dry-human-mandible than models with CT-data.

Conclusion: The current study shows that CBCT generates significantly better data than CT in producing mandibular models. The first choice for manufacturing of human mandible is BJ and the second choice is the technology of SLA.

Introduction: Venovenous artificial placenta (VVAP) may mimic the intrauterine environment for maintaining fetal circulation. However, changes in ventricular function in fetal goats undergoing VVAP support remain unclear.

Methods: Pump-assisted VVAPs were established in five fetal goats for 9 h. The myocardial performance index (Tei index), cardiac output (CO), and blood biochemical parameters were measured during VVAP support.

Results: An increasing trend of the right ventricular (RV) Tei index was seen during VVAP support (p for trend < 0.01). The right ventricular cardiac output (RVCO) increased after the initiation of VVAP, while a significant trend of reduction was observed after 3 h (p for trend = 0.03). During VVAP support, we observed remarkable elevations of plasma cTnI and arterial lactic acid, which were positively correlated with the RV Tei index, but not the left ventricular (LV) Tei index, LVCO, and RVCO.

Conclusions: The RVCO increases initially while a tendency of decrease could be observed during VVAP support. Special attention should be paid to right ventricular dysfunction during VVAP support.