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Resuscitation Plus Sep 2024Minimizing cardiac arrest times is critical in extracorporeal cardiopulmonary resuscitation (ECPR). Pre-primed extra corporeal membrane oxygenator (ECMO) is used for...
AIM
Minimizing cardiac arrest times is critical in extracorporeal cardiopulmonary resuscitation (ECPR). Pre-primed extra corporeal membrane oxygenator (ECMO) is used for this, but knowledge is limited to experimental studies. We prospectively investigated oxygenator function and sterility in dry plus wet pre-priming in a clinical setting.
METHODS
This prospective clinical study included 107 ECMO circuits used at Sahlgrenska University Hospital between October 2019 and December 2021. Circuits underwent dry set-up, followed by wet priming when the previous wet-primed circuit was used. Sterility was assessed by culturing the priming solution. Oxygenator function parameters, including sweep gas flow, fraction of oxygen (FiO), and oxygenator resistance, were analyzed at ECMO initiation and during treatment using linear mixed models.
RESULTS
Median total set-up time was 14 days (range 0-97), with a median wet prime time of 6 days (range 0-57). 103 of 105 circuits with culture results were negative, two showed bacterial growth (coagulase-negative staphylococci and ). Wet prime time did not significantly affect initial oxygenator function. Oxygenator resistance and FiO increased during ECMO treatment (0.035 mmHg/L min (95 % confidence interval (CI) 0.015-0.055) < 0.001, and 2.19 % (0.92-3.46) = 0.009), but these changes were unrelated to wet prime time.
CONCLUSION
Wet pre-priming of ECMO circuits for up to 57 days did not affect oxygenator function. The low incidence of bacterial growth (1.9 %) suggests that pre-primed ECMO generally maintain sterility and can facilitate rapid ECPR initiation. However, bacterial growth highlights the need for caution in non-urgent cases. Culturing the circuit at initiation can mitigate this risk.
PubMed: 38912528
DOI: 10.1016/j.resplu.2024.100680 -
Frontiers in Physiology 2024This study was undertaken to explore the potential therapeutic effects of Tongyang Huoxue Granules (TYHX) on sinoatrial node (SAN) dysfunction, a cardiac disorder...
INTRODUCTION
This study was undertaken to explore the potential therapeutic effects of Tongyang Huoxue Granules (TYHX) on sinoatrial node (SAN) dysfunction, a cardiac disorder characterized by impaired impulse generation or conduction. The research question addressed whether TYHX could positively influence SAN ion channel function, specifically targeting the sodium-calcium exchanger ( ) and L-type calcium channel ( ) of the SAN.
METHODS
Sinoatrial node cells (SANCs) were isolated and cultured from neonatal Japanese big-eared white rabbits within 24 h of birth. The study encompassed five groups: Control, H/R (hypoxia/reoxygenation), H/R+100 μg/mL TYHX, H/R+200 μg/mL TYHX, and H/R+400 μg/mL TYHX. The H/R model, simulating hypoxia/reoxygenation stress, was induced within 5 days of culture. Whole-cell patch clamp technique was employed to record currents following a 3-min perfusion and stabilization period with TYHX.
RESULTS
TYHX administration demonstrated improvements in the ignition phase of impaired SANCs. The half-maximal effective dose of TYHX, as determined by SANC beating frequency, was found to be 323.63 μg/mL. Inward current density of increased in response to TYHX (200 and 400 μg/mL), while TYHX enhanced current density in H/R SANCs, with 400 μg/mL exhibiting greater efficacy. Additionally, TYHX regulated the gating mechanisms of by right-shifting the steady-state inactivation curve and accelerating recovery from inactivation. Notably, TYHX increased the activation time constant under 200 and 400 μg/mL, prolonged the fast inactivation time constant τ1 with 400 μg/mL, and extended the slow inactivation time constant τ2 with 100 and 400 μg/mL.
DISCUSSION AND CONCLUSION
The findings suggest that TYHX may hold promise as a therapeutic intervention for sinus node dysfunction, offering potential avenues for drug development aimed at safeguarding SAN function.
PubMed: 38911325
DOI: 10.3389/fphys.2024.1402478 -
Biomedicine & Pharmacotherapy =... Jun 2024Peptide-functionalized hydrogel is one of commonly used biomaterials to introduce hydrogel-induced vessel regeneration. Despite many reports about the discoveries of...
Peptide-functionalized hydrogel is one of commonly used biomaterials to introduce hydrogel-induced vessel regeneration. Despite many reports about the discoveries of high-active peptides (or ligands) for regeneration, the study on the conjugating methods for the hydrogel functionalization with peptides is limited. Here, we compared the vasculogenic efficacy of the peptide-functionalized hydrogels prepared by two commonly used conjugating methods, 1-ethyl-3-(3-dimethylamino propyl) carbodiimide (EDC) and Click methods, through cell models, organ-on-chips models, animal models, and RNA sequencing analysis. Two vascular-related cell types, the human umbilical vein endothelial cells (HUVECs) and the adipose-derived stem cells (ADSCs), have been cultured on the hydrogel surfaces prepared by EDC/Click methods. It showed that the hydrogels prepared by Click method supported the higher vasculogenic activities while the ones made by EDC method compromised the peptide activities on hydrogels. The vasculogenesis assays further revealed that hydrogels prepared by Click method promoted a better vascular network formation. In a critical ischemic hindlimb model, only the peptide-functionalized hydrogels prepared by Click method successfully salvaged the ischemic limb, significantly improved blood perfusion, and enhanced the functional recoveries (through gait analysis and animal behavior studies). RNA sequencing studies revealed that the hydrogels prepared by Click method significantly promoted the PI3K-AKT pathway activation compared to the hydrogels prepared by EDC method. All the results suggested that EDC method compromised the functions of the peptides, while Click method preserved the vascular regenerating capacities of the peptides on the hydrogels, illustrating the importance of the conjugating method during the preparation of the peptide-functionalized hydrogels.
PubMed: 38906023
DOI: 10.1016/j.biopha.2024.116959 -
Nature Communications Jun 2024Hepatocellular carcinoma frequently recurs after surgery, necessitating personalized clinical approaches based on tumor avatar models. However, location-dependent oxygen...
Hepatocellular carcinoma frequently recurs after surgery, necessitating personalized clinical approaches based on tumor avatar models. However, location-dependent oxygen concentrations resulting from the dual hepatic vascular supply drive the inherent heterogeneity of the tumor microenvironment, which presents challenges in developing an avatar model. In this study, tissue samples from 12 patients with hepatocellular carcinoma are cultured directly on a chip and separated based on preference of oxygen concentration. Establishing a dual gradient system with drug perfusion perpendicular to the oxygen gradient enables the simultaneous separation of cells and evaluation of drug responsiveness. The results are further cross-validated by implanting the chips into mice at various oxygen levels using a patient-derived xenograft model. Hepatocellular carcinoma cells exposed to hypoxia exhibit invasive and recurrent characteristics that mirror clinical outcomes. This chip provides valuable insights into treatment prognosis by identifying the dominant hepatocellular carcinoma type in each patient, potentially guiding personalized therapeutic interventions.
Topics: Carcinoma, Hepatocellular; Humans; Liver Neoplasms; Animals; Mice; Oxygen; Tumor Microenvironment; Cell Line, Tumor; Male; Female; Xenograft Model Antitumor Assays; Middle Aged; Lab-On-A-Chip Devices
PubMed: 38879551
DOI: 10.1038/s41467-024-49386-8 -
Scientific Reports Jun 2024Here we report the effects of low-intensity pulsed ultrasound (LIPUS) on symptoms in peripheral arterial disease patients with Buerger disease. A double-blinded and... (Randomized Controlled Trial)
Randomized Controlled Trial
Here we report the effects of low-intensity pulsed ultrasound (LIPUS) on symptoms in peripheral arterial disease patients with Buerger disease. A double-blinded and randomized study with active and inactive LIPUS was conducted. We assessed symptoms in leg circulation during a 24-week period of LIPUS irradiation in 12 patients with Buerger disease. Twelve patients without LIPUS irradiation served as controls. The pain intensity on visual analog score was significantly decreased after 24-week LIPUS treatment. Skin perfusion pressure was significantly increased in patients who received LIPUS treatment. There was no significant difference in symptoms and perfusion parameters in the control group. No severe adverse effects were observed in any of the patients who underwent LIPUS treatment. LIPUS is noninvasive, safe and effective option for improving symptoms in patients with Buerger disease.
Topics: Humans; Male; Female; Double-Blind Method; Middle Aged; Thromboangiitis Obliterans; Ultrasonic Therapy; Adult; Ultrasonic Waves; Treatment Outcome; Skin; Aged
PubMed: 38871832
DOI: 10.1038/s41598-024-64118-0 -
Nature Communications Jun 2024Generating 3D bone cell networks in vitro that mimic the dynamic process during early bone formation remains challenging. Here, we report a synthetic biodegradable...
Generating 3D bone cell networks in vitro that mimic the dynamic process during early bone formation remains challenging. Here, we report a synthetic biodegradable microporous hydrogel for efficient formation of 3D networks from human primary cells, analysis of cell-secreted extracellular matrix (ECM) and microfluidic integration. Using polymerization-induced phase separation, we demonstrate dynamic in situ formation of microporosity (5-20 µm) within matrix metalloproteinase-degradable polyethylene glycol hydrogels in the presence of living cells. Pore formation is triggered by thiol-Michael-addition crosslinking of a viscous precursor solution supplemented with hyaluronic acid and dextran. The resulting microporous architecture can be fine-tuned by adjusting the concentration and molecular weight of dextran. After encapsulation in microporous hydrogels, human mesenchymal stromal cells and osteoblasts spread rapidly and form 3D networks within 24 hours. We demonstrate that matrix degradability controls cell-matrix remodeling, osteogenic differentiation, and deposition of ECM proteins such as collagen. Finally, we report microfluidic integration and proof-of-concept osteogenic differentiation of 3D cell networks under perfusion on chip. Altogether, this work introduces a synthetic microporous hydrogel to efficiently differentiate 3D human bone cell networks, facilitating future in vitro studies on early bone development.
Topics: Humans; Hydrogels; Mesenchymal Stem Cells; Osteogenesis; Cell Differentiation; Osteoblasts; Extracellular Matrix; Porosity; Cell Culture Techniques, Three Dimensional; Polyethylene Glycols; Tissue Engineering; Hyaluronic Acid; Cells, Cultured; Tissue Scaffolds; Dextrans
PubMed: 38871693
DOI: 10.1038/s41467-024-49280-3 -
Molecular Therapy. Methods & Clinical... Jun 2024With safety and efficacy demonstrated over hundreds of clinical trials in the last 30 years, along with at least six recent global marketing authorizations achieved...
With safety and efficacy demonstrated over hundreds of clinical trials in the last 30 years, along with at least six recent global marketing authorizations achieved since 2017, recombinant adeno-associated viruses (rAAVs) have been established as the leading therapeutic gene transfer vector for rare, monogenic diseases. Significant advances in manufacturing technology have been made in the last few decades to address challenges with GMP production of rAAV products, although yield, cost, scalability, and quality remain a challenge. With transient transfection processes established as a manufacturing platform for multiple commercial AAV products, there remains significant yield, cost, robustness, and scalability constraints that need to be resolved to enable a reliable supply of rAAV products for global patient access. The development of stable producer cell lines for rAAV products has enabled scalability and, in some cases, improvements in productivity. Herein we describe a novel AAV perfusion-enhanced expression (APEX) process, resulting in higher maximum cell densities in the production bioreactor with a 3- to 6-fold increase in volumetric productivity. This process has been successfully demonstrated across multiple serotypes in large scale cell culture with titers approaching 1 × 10 GC/mL. The APEX production platform marks a significant leap forward in the efficient and effective manufacturing of rAAV vector products.
PubMed: 38868441
DOI: 10.1016/j.omtm.2024.101266 -
Scientific Reports Jun 2024Snakebite envenomation is a major public health issue which causes severe morbidity and mortality, affecting millions of people annually. Of a diverse range of clinical...
Snakebite envenomation is a major public health issue which causes severe morbidity and mortality, affecting millions of people annually. Of a diverse range of clinical manifestations, local and systemic haemorrhage are of particular relevance, as this may result in ischemia, organ failure and even cardiovascular shock. Thus far, in vitro studies have failed to recapitulate the haemorrhagic effects observed in vivo. Here, we present an organ-on-a-chip approach to investigate the effects of four different snake venoms on a perfused microfluidic blood vessel model. We assess the effect of the venoms of four snake species on epithelial barrier function, cell viability, and contraction/delamination. Our findings reveal two different mechanisms by which the microvasculature is being affected, either by disruption of the endothelial cell membrane or by delamination of the endothelial cell monolayer from its matrix. The use of our blood vessel model may shed light on the key mechanisms by which tissue-damaging venoms exert their effects on the capillary vessels, which could be helpful for the development of effective treatments against snakebites.
Topics: Animals; Snake Venoms; Lab-On-A-Chip Devices; Humans; Endothelial Cells; Hemorrhage; Cell Survival; Snake Bites; Human Umbilical Vein Endothelial Cells; Microphysiological Systems
PubMed: 38834598
DOI: 10.1038/s41598-024-60282-5 -
Molecular Therapy. Methods & Clinical... Jun 2024Quasi-perfusion culture was employed to intensify lentiviral vector (LV) manufacturing using a continuous stable producer cell line in an 8-day process. Initial studies...
Quasi-perfusion culture was employed to intensify lentiviral vector (LV) manufacturing using a continuous stable producer cell line in an 8-day process. Initial studies aimed to identify a scalable seeding density, with 3, 4, and 5 × 10 cells cm providing similar specific productivities of infectious LV. Seeding at 3 × 10 cells cm was selected, and the quasi-perfusion was modulated to minimize inhibitory metabolite accumulation and vector exposure at 37°C. Similar specific productivities of infectious LV and physical LV were achieved at 1, 2, and 3 vessel volumes per day (VVD), with 1 VVD selected to minimize downstream processing volumes. The optimized process was scaled 50-fold to 1,264 cm flasks, achieving similar LV titers. However, scaling up beyond this to a 6,320 cm multilayer flask reduced titers, possibly from suboptimal gas exchange. Across three independent processes in 25 cm to 6,320 cm flasks, reproducibility was high with a coefficient of variation of 7.7% ± 2.9% and 11.9% ± 3.0% for infectious and physical LV titers, respectively. The optimized flask process was successfully transferred to the iCELLis Nano (Cytiva) fixed-bed bioreactor, with quasi-perfusion at 1 VVD yielding 1.62 × 10 TU.
PubMed: 38827249
DOI: 10.1016/j.omtm.2024.101264 -
STAR Protocols Jun 2024Microfluidic single-cell cultivation (MSCC) is a powerful tool for investigating the cellular behavior of various cell types at the single-cell level. Here, we present a...
Microfluidic single-cell cultivation (MSCC) is a powerful tool for investigating the cellular behavior of various cell types at the single-cell level. Here, we present a protocol specifically developed for the reliable and reproducible MSCC of industrially relevant Chinese hamster ovary (CHO) suspension cell lines. We summarize critical experimental steps from the initial seed train up to the final MSCC experiment, with a special focus on pre-culture management and medium preparation, device inoculation, and the establishment of a constant medium perfusion.
Topics: Animals; CHO Cells; Cricetulus; Cell Culture Techniques; Single-Cell Analysis; Cricetinae; Microfluidics; Microfluidic Analytical Techniques
PubMed: 38824641
DOI: 10.1016/j.xpro.2024.103106