Based on the principles of bionics, the hydrophilicity, bacteriostasis, and alkalinity of chitosan (CS) have been utilized to enhance the hydrophilic and antibacterial properties of a polylactic acid (PLA) bone scaffold. They also neutralize the acidity generated by its degradation. The incorporation of nano-hydroxyapatite (n-HA) effectively improves the osteogenic properties of PLA. The PLA-CS graft was first synthesized by grafting CS onto PLA using ferulic acid (FA), resulting in a CS-modified, PLA-doped n-HA (PLA-CS/n-HA) bone scaffold. The prepared PLA-CS/n-HA bone scaffold facilitated the formation of new bone and tissue attachment. More importantly, the acidity from PLA degradation in the PLA-CS/n-HA scaffold was alleviated to a certain extent. Its hydrophilicity and compressive strength were enhanced compared to the PLA bone scaffold, and its antibacterial activity was stronger against Staphylococcus aureus than against Escherichia coli. After a 12 h co-culture with the PLA-CS/n-HA bone scaffold, the relative adhesion rate of MC3T3-E1 cells was 118.95%. After 14 days of inducing MC3T3-E1 cells on the PLA-CS/n-HA bone scaffold, the MC3T3-E1 cells exhibited preliminary differentiation and alkaline phosphatase activity reached 1.23. The PLA-CS/n-HA bone scaffold received a cytotoxicity grade of class 0, indicating no cytotoxicity.

Ex situ heart perfusion (ESHP) allows longer preservation times and provides the opportunity to assess cardiac function. The goal of our study was to evaluate the impact of the treatment of beating heart in normothermic ESHP based on ECMO technology on post-transplant graft function in an animal model. Ten healthy male adult domestic pigs weighting 90-95 kg were selected to donate hearts n = 5 donors for prolonged (24 h) normothermic ESHP based on ECMO technology and n = 5 recipients. Perfusion system consisted of ECMO oxygenator, centrifugal pump, tubing and integrated ultrafiltration device. Baseline echocardiographic and hemodynamic parameters, along with coronary angiography, were evaluated before each heart explantation, during ex situ perfusion, and prior to transplantation. Following 24 h of ESHP, orthotopic heart transplants were performed utilizing the bicaval technique during 4 posttransplant hours. Outcomes of interest were the change in lactate, ischemic time, perfusion time, hemodynamic evaluation of the heart, and morphologic changes after heart transplantation. Heart harvesting, continuous ESHP for 24 h followed by orthotopic transplantation was performed. The mean duration was 1440 ± 80 min. Echocardiographic evaluation of the heart during exvivo perfusion revealed a normal trend of Tissue Doppler Imaging (TDI) parameters. The mean left ventricular ejection fraction after heart transplantation was 48% (±0.7), cardiac output and cardiac index after transplantation was 6.0 L/min (±0.7) and 3.1 (±0.2) l/min/m2, respectively. For over 4 h post-transplant, there was no evidence of graft dysfunction. This study demonstrates that hearts without prior DBD/DCD exposure or cold ischemic injury are able to recover and maintain functional viability following 24 h of ex-situ heart perfusion.

ABSTRACT Background Acute kidney injury (AKI) remains one of the most frequent and prognostically relevant complications following cardiac surgery, even in the era of modern cardiopulmonary bypass (CPB) management and goal‐directed perfusion. Cardiac surgery–associated AKI (CSA‐AKI) is associated with increased postoperative morbidity, prolonged hospitalization, neurocognitive complications, and reduced early as well as long‐term survival. Although optimization of macrocirculatory parameters and oxygen delivery has demonstrated benefits, renal injury often occurs despite apparently adequate perfusion and oxygenation. Recent evidence suggests that CPB‐related metabolic stress and protein catabolism contribute to renal vulnerability. Indeed, intravenous amino acid administration has emerged as a novel metabolic strategy for renal protection. Materials and Methods This narrative review was informed by a structured literature search of PubMed/MEDLINE, Embase, and the Cochrane Library, covering publications from database inception through March 2025. Search terms included combinations of “acute kidney injury,” “cardiac surgery,” “cardiopulmonary bypass,” “amino acids,” “intravenous amino acid infusion,” “renal protection,” and “goal‐directed perfusion”. Randomized controlled trials, meta‐analyses, systematic reviews, secondary analyses, and relevant narrative reviews published in English were considered. Particular emphasis was placed on high‐quality evidence, including the PROTECTION randomized trial, contemporary meta‐analyses, and consensus or expert reviews addressing cardiac surgery–associated acute kidney injury and perioperative metabolic interventions. Results The literature search identified 124 records; 18 articles were included in the final narrative synthesis after title, abstract, and full‐text evaluation. The selected literature comprised a multicenter randomized controlled trial, secondary analyses of randomized data, meta‐analyses/systematic reviews, narrative or expert reviews, and observational or mechanistic studies addressing CSA‐AKI. The evidence indicates that CSA‐AKI results from an interaction between altered renal perfusion, inflammation, ischemia–reperfusion injury, and CPB‐induced metabolic derangement. Intravenous amino acid infusion was consistently associated with reduced postoperative AKI incidence, particularly in patients with preexisting chronic kidney disease, without significant safety concerns. These findings support amino acid administration as a metabolic adjunct to goal‐directed perfusion rather than a standalone intervention. Conclusions Intravenous amino acid infusion is a recent strategy to reduce AKI in cardiac surgery. By targeting the CPB‐induced metabolic stress, amino acid administration complements goal‐directed perfusion and expands current AKI prevention paradigms beyond hemodynamic optimization alone. Future research should focus on CPB‐specific timing, dosing strategies, and integration of metabolic support into multimodal AKI prevention bundles.

In cases of sepsis and an excessive inflammatory response, continuous renal replacement therapy (CRRT) has the potential to provide immunomodulation by removing cytokines and inflammatory mediators. This study aimed to evaluate the efficacy of the Oxiris filter, which has endotoxin and cytokine adsorption properties, in the pediatric population and compare it with conventional filters. This retrospective study examined 42 pediatric intensive care patients diagnosed with sepsis or multisystem inflammatory syndrome in children (MIS-C). The patients received CRRT with either Oxiris filters (n = 21) or conventional filters (n = 21). The study compared hemodynamic and laboratory parameters, as well as mortality. The two groups had similar baseline characteristics and disease severity scores (PRISM III, PELOD II, and OFI). Overall mortality rates were comparable between the Oxiris and conventional filter groups (52.4% vs. 57.1%; p = 0.757), whereas 28-day mortality was significantly lower in the Oxiris group (28.6% vs. 61.9%; p = 0.030). Within 24 h, both filters showed comparable improvements in VIS, heart rate, mean arterial pressure (MAP), lactate, bicarbonate, and albumin levels (all p > 0.05); no significant changes were observed in C-reactive protein (CRP) or procalcitonin levels. Subgroup analysis revealed a more pronounced VIS reduction (p = 0.013), less adequate acidosis correction (p = 0.022), and higher PELOD-II scores (p = 0.026) among non-survivors. Thrombocytopenia was the most common complication, with no difference between the two groups. In critically ill pediatric patients, Oxiris and conventional filters produced comparable short-term hemodynamic, metabolic, and inflammatory effects during CRRT. While overall mortality did not differ between the groups, 28-day mortality was lower in the Oxiris cohort. Further multicenter, prospective research is warranted to confirm these findings and to identify specific pediatric subgroups that may benefit from Oxiris therapy.

Computational fluid dynamics (CFD) has become an essential design tool for ventricular assist devices (VADs), where the goal of maximizing performance often conflicts with biocompatibility. This tradeoff becomes even more pronounced in pediatric applications due to the stringent size constraints imposed by the smaller patient population. This study presents an automated CFD-driven shape optimization of a new intermediate diffuser stage for the PediaFlow pediatric VAD, positioned immediately downstream of the impeller to improve pressure recovery. We adopted a multi-objective optimization approach to maximize pressure recovery while minimizing hemolysis. The proposed diffuser stage was isolated from the rest of the flow domain, enabling efficient evaluation of over 450 design variants using Sobol sequence, which yielded a Pareto front of nondominated solutions. The selected best candidate was further refined using a local T-search algorithm. We then incorporated the optimized front diffuser into the full pump for CFD verification and invitro validation. We identified critical dependencies where longer blades increased pressure recovery but also hemolysis, while the wrap angle showed a strong parabolic relationship with pressure recovery but a monotonic relationship with hemolysis. Counterintuitively, configurations with fewer blades (2, 3) consistently outperformed those with more blades (4, 5) in both metrics. The optimized two-blade design enabled operation at lower pump speeds (14 000 vs. 16 000 RPM), improving hydraulic efficiency from 26.3% to 32.5% and reducing hemolysis by 31%. This approach demonstrates that multi-objective CFD optimization can systematically explore complex design spaces while balancing competing priorities of performance and hemocompatibility for pediatric VADs.

The views expressed in this article are those of the author and do not necessarily represent the views of the National Heart, Lung, and Blood Institute, the National Institutes of Health, or the United States Department of Health and Human Services. The other authors have no conflicts of interest to disclose. Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.

The authors declare no conflicts of interest.