Role of VV ECMO tracheal surgery and carinal resection: Two case reports.

The aim of this study is to describe the anaesthesia management of two patients undergoing carinal resection under veno-venous extracorporeal membrane oxygenation (VV ECMO). In both cases, anaesthesia was induced and then maintained with inhalational agents during pneumonectomy and mediastinoscopy (respectively). Then the jugular and femoral veins were cannulated and VV ECMO was started after heparinization. One of the patients presented bleeding during surgery, which was treated with low-dose vasopressors (norepinephrine) and transfusion of platelets, fresh frozen plasma, and concentrated red blood cells. During VV ECMO, anaesthesia was maintained with target-controlled infusion of propofol. VV ECMO can be expected to improve surgical conditions in tracheal surgery; however, it is still a novel technique in this context. In selected patients, it would guarantee ventilatory support during carinal resection, but it is essential to carefully plan anaesthesia maintenance and prepare for VV ECMO-related complications. This technique should only be used in tertiary centres with experience in VV ECMO management.

The management of paediatric acute pain in Spain in 2021: Results of a national survey among paediatric anaesthesiologists.

OBJECTIVE: To improve knowledge about routine clinical practice in the management of paediatric acute pain in Spain. METHODS: A telematic survey was conducted via the Internet on a representative sample of healthcare professionals involved in the management of paediatric acute pain (specifically anaesthesiologists) in Spain. The survey included 28 questions about their usual clinical practice in the assessment and treatment of acute pain, and also training and organisational aspects in paediatric acute pain. RESULTS: The survey was completed during March 2021 by 150 specialists in anaesthesiology. The respondents widely experienced in the management of acute paediatric pain (mean years of experience: 14.3: SD: 7.8), essentially in acute postoperative pain (97% of cases). Although 80% routinely used validated paediatric acute pain assessment scales, only 2.6% used specific scales adapted for patients with cognitive impairment. Most of the respondents routinely used analgesic drugs such as paracetamol (99%) or metamizole (92%), but only 84% complemented these drugs with a loco-regional blocking technique or other non-steroidal anti-inflammatory drugs (62%). Furthermore, only 62.7% acknowledged having received specific training in paediatric acute pain, only 45% followed hospital institutional protocols, and a scant 28% did so through paediatric pain units. CONCLUSIONS: The survey identified important points for improvement in the training and organisation of acute pain management in Spanish paediatric patients.

Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR), Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management.

The Airway Management section of the Spanish Society of Anesthesiology, Resuscitation, and Pain Therapy (SEDAR), the Spanish Society of Emergency Medicine (SEMES), and the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) present the Guide for the comprehensive management of difficult airway in adult patients. Its principles are focused on the human factor, cognitive processes for decision-making in critical situations, and optimization in the progression of strategies application to preserve adequate alveolar oxygenation in order to enhance safety and the quality of care. The document provides evidence-based recommendations, theoretical-educational tools, and implementation tools, mainly cognitive aids, applicable to airway management in the fields of anesthesiology, critical care, emergencies, and prehospital medicine. For this purpose, an extensive literature search was conducted following PRISMA-R guidelines and was analyzed using the GRADE methodology. Recommendations were formulated according to the GRADE methodology. Recommendations for sections with low-quality evidence were based on expert opinion through consensus reached via a Delphi questionnaire.

Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR) Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management. Part II.

The Airway Management section of the Spanish Society of Anesthesiology, Resuscitation, and Pain Therapy (SEDAR), the Spanish Society of Emergency Medicine (SEMES), and the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) present the Guide for the comprehensive management of difficult airway in adult patients. Its principles are focused on the human factor, cognitive processes for decision-making in critical situations, and optimization in the progression of strategies application to preserve adequate alveolar oxygenation in order to enhance safety and the quality of care. The document provides evidence-based recommendations, theoretical-educational tools, and implementation tools, mainly cognitive aids, applicable to airway management in the fields of anesthesiology, critical care, emergencies, and prehospital medicine. For this purpose, an extensive literature search was conducted following PRISMA-R guidelines and was analyzed using the GRADE methodology. Recommendations were formulated according to the GRADE methodology. Recommendations for sections with low-quality evidence were based on expert opinion through consensus reached via a Delphi questionnaire.

Description of Intensive Care and Intermediate Care resources managed by Anaesthesiology Departments in Spain and their adaptation capacity during the COVID-19 pandemic.

INTRODUCTION: It is essential to understand the strategic importance of intensive care resources in the sustainable organisation of healthcare systems. Our objective has been to identify the intensive and intermediate care beds managed by Anaesthesiology and Resuscitation Services (A-ICU and A-IMCU) in Spain, their human and technical resources, and the changes made to these resources during the COVID-19 pandemic. MATERIAL AND METHODS: Prospective observational study performed between December 2020 and July 2021 to register the number and characteristics of A-ICU and A-IMCU beds in hospitals listed in the catalogue published by the Spanish Ministry of Health. RESULTS: Data were obtained from 313 hospitals (98% of all hospitals with more than 500 beds, 70% of all hospitals with more than 100 beds). One hundred and forty seven of these hospitals had an A-ICU with a total of 1702 beds. This capacity increased to 2107 (124%) during the COVID-19 pandemic. Three hundred and eight hospitals had an A-IMCU with a total of 3470 beds, 52.9% (2089) of which provided long-term care. The hospitals had 1900 ventilators, at a ratio of 1.07 respirators per A-ICU; 1559 anaesthesiologists dedicated more than 40% of their working time to intensive care. The nurse-to-bed ratio in A-ICUs was 2.8. DISCUSSION: A large proportion of fully-equipped ICU and IMCU beds in Spanish hospitals are managed by the anaesthesiology service. A-ICU and A-IMCUs have shown an extraordinary capacity to adapt their resources to meet the increased demand for intensive care during the COVID-19 pandemic.

A critical review of the perioperative fluid therapy and hemodynamic monitoring recommendations of the Enhanced Recovery of the Adult Pathway (RICA): A position statement of the fluid therapy and hemodynamic monitoring Subcommittee of the Hemostasis, Transfusion Medicine and Fluid Therapy Section (SHTF) of the Spanish Society of Anesthesiology and Critical Care (SEDAR).

In an effort to standardize perioperative management and improve postoperative outcomes of adult patients undergoing surgery, the Ministry of Health, through the Spanish Multimodal Rehabilitation Group (GERM), and the Aragonese Institute of Health Sciences, in collaboration with multiple Spanish scientific societies and based on the available evidence, published in 2021 the Spanish Intensified Adult Recovery (RICA) guideline. This document includes 12 perioperative measures related to fluid therapy and hemodynamic monitoring. Fluid administration and hemodynamic monitoring are not straightforward but are directly related to postoperative patient outcomes. The Fluid Therapy and Hemodynamic Monitoring Subcommittee of the Hemostasis, Transfusion Medicine and Fluid Therapy Section (SHTF) of the Spanish Society of Anesthesiology and Critical Care (SEDAR) has reviewed these recommendations and concluded that they should be revised as they do not follow an adequate methodology.

Research priorities in perioperative fluid therapy and hemodynamic monitoring: A Delphi Consensus Survey from the Fluid Therapy and Hemodynamic Monitoring Subcommittee of the Hemostasis, Transfusion Medicine and Fluid Therapy Section (SHTF) of the Spanish Society of Anesthesiology and Critical Care (SEDAR).

BACKGROUND: Research in fluid therapy and perioperative hemodynamic monitoring is difficult and expensive. The objectives of this study were to summarize these topics and to prioritize these topics in order of research importance. METHODS: Electronic structured Delphi questionnaire over three rounds among 30 experts in fluid therapy and hemodynamic monitoring identified through the Fluid Therapy and Hemodynamic Monitoring Subcommittee of the Hemostasis, Transfusion Medicine and Fluid Therapy Section of the Spanish Society of Anesthesiology and Critical Care. RESULTS: 77 topics were identified and ranked in order of prioritization. Topics were categorized into themes of crystalloids, colloids, hemodynamic monitoring and others. 31 topics were ranked as essential research priority. To determine whether intraoperative hemodynamic optimization algorithms based on the invasive or noninvasive Hypotension Prediction Index versus other management strategies could decrease the incidence of postoperative complications. As well as whether the use of renal stress biomarkers together with a goal-directed fluid therapy protocol could reduce hospital stay and the incidence of acute kidney injury in adult patients undergoing non-cardiac surgery, reached the highest consensus. CONCLUSIONS: The Fluid Therapy and Hemodynamic Monitoring Subcommittee of the Hemostasis, Transfusion Medicine and Fluid Therapy Section of the Spanish Society of Anesthesiology and Critical Care will use these results to carry out the research.

Optical properties of ZnFe2O4 nanoparticles and Fe-decorated inversion domain boundaries in ZnO.

The maximum efficiency of solar cells utilizing a single layer for photovoltaic conversion is given by the single junction Shockley-Queisser limit. In tandem solar cells, a stack of materials with different band gaps contribute to the conversion, enabling tandem cells to exceed the single junction Shockley-Queisser limit. An intriguing variant of this approach is to embed semiconducting nanoparticles in a transparent conducting oxide (TCO) solar cell front contact. This alternative route would enhance the functionality of the TCO layer, allowing it to participate directly in photovoltaic conversion via photon absorption and charge carrier generation in the nanoparticles. Here, we demonstrate the functionalization of ZnO through incorporation of either ZnFe2O4 spinel nanoparticles (NPs) or inversion domain boundaries (IDBs) decorated by Fe. Diffuse reflectance spectroscopy and electron energy loss spectroscopy show that samples containing spinel particles and samples containing IDBs decorated by Fe both display enhanced absorption in the visible range at around 2.0 and 2.6 eV. This striking functional similarity was attributed to the local structural similarity around Fe-ions in spinel ZnFe2O4 and at Fe-decorated basal IDBs. Hence, functional properties of the ZnFe2O4 arise already for the two-dimensional basal IDBs, from which these planar defects behave like two-dimensional spinel-like inclusions in ZnO. Cathodoluminescence spectra reveal an increased luminescence around the band edge of spinel ZnFe2O4 when measuring on the spinel ZnFe2O4 NPs embedded in ZnO, whereas spectra from Fe-decorated IDBs could be deconvoluted into luminescence contributions from bulk ZnO and bulk ZnFe2O4.

Regulatory and metabolic adaptations in the nitrogen assimilation of marine picocyanobacteria.

Prochlorococcus and Synechococcus are the two most abundant photosynthetic organisms on Earth, with a strong influence on the biogeochemical carbon and nitrogen cycles. Early reports demonstrated the streamlining of regulatory mechanisms in nitrogen metabolism and the removal of genes not strictly essential. The availability of a large series of genomes, and the utilization of latest generation molecular techniques have allowed elucidating the main mechanisms developed by marine picocyanobacteria to adapt to the environments where they thrive, with a particular interest in the strains inhabiting oligotrophic oceans. Given that nitrogen is often limited in those environments, a series of studies have explored the strategies utilized by Prochlorococcus and Synechococcus to exploit the low concentrations of nitrogen-containing molecules available in large areas of the oceans. These strategies include the reduction in the GC and the cellular protein contents; the utilization of truncated proteins; a reduced average amount of N in the proteome; the development of metabolic mechanisms to perceive and utilize nanomolar nitrate concentrations; and the reduced responsiveness of key molecular regulatory systems such as NtcA to 2-oxoglutarate. These findings are in sharp contrast with the large body of knowledge obtained in freshwater cyanobacteria. We will outline the main discoveries, stressing their relevance to the ecological success of these important microorganisms.

Peripheral VA-ECMO left ventricular dysfunction: A combined biventricular assistance two case-report.

We report 2 patients with cardiogenic shock that developed severe left ventricular dysfunction due to a non-opening aortic valve while on peripheral VA-ECMO (Veno-Arterial Extracorporeal Membrane Oxygenator). Patients were managed combining a LV (Left Ventricle) mechanical assist device, and central VA - ECMO to support the right ventricle, thus providing full circulatory and respiratory assistance. Patients were able to bridge to cardiac transplantation. We therefore recommend such combination in patients with severe LV dysfunction while on p-ECMO (peripheral ECMO) support.

Improved Magneto-Microfluidic Separation of Nanoparticles through Formation of the ß-Cyclodextrin-Curcumin Inclusion Complex.

Molecular adsorption to the nanoparticle surface may switch the colloidal interactions from repulsive to attractive and promote nanoparticle agglomeration. If the nanoparticles are magnetic, then their agglomerates exhibit a much stronger response to external magnetic fields than individual nanoparticles. Coupling between adsorption, agglomeration, and magnetism allows a synergy between the high specific area of nanoparticles (∼100 m2/g) and their easy guidance or separation by magnetic fields. This yet poorly explored concept is believed to overcome severe restrictions for several biomedical applications of magnetic nanoparticles related to their poor magnetic remote control. In this paper, we test this concept using curcumin (CUR) binding (adsorption) to ß-cyclodextrin (ßCD)-coated iron oxide nanoparticles (IONP). CUR adsorption is governed by host-guest hydrophobic interactions with ßCD through the formation of 1:1 and, possibly, 2:1 ßCD:CUR inclusion complexes on the IONP surface. A 2:1 stoichiometry is supposed to promote IONP primary agglomeration, facilitating the formation of the secondary needle-like agglomerates under external magnetic fields and their magneto-microfluidic separation. The efficiency of these field-induced processes increases with CUR concentration and ßCD surface density, while their relatively short timescale (<5 min) is compatible with magnetic drug delivery application.

Peripheral VA-ECMO left ventricular dysfunction: A combined biventricular assistance two case-report. / Asistencia biventricular en el manejo de la disfunción ventricular izquierda secundaria a ECMO-VA periférica: a propósito de 2 casos.

We report 2patients with cardiogenic shock that developed severe left ventricular dysfunction due to a non-opening aortic valve while on peripheral VA-ECMO (Veno-Arterial Extracorporeal Membrane Oxygenator). Patients were managed combining a LV (Left Ventricle) mechanical assist device, and central VA - ECMO to support the right ventricle, thus providing full circulatory and respiratory assistance. Patients were able to bridge to cardiac transplantation. We therefore recommend such combination in patients with severe LV dysfunction while on p-ECMO (peripheral ECMO) support.

Summary of recommendations and key points of the consensus of Spanish scientific societies (SEPAR, SEMICYUC, SEMES; SECIP, SENEO, SEDAR, SENP) on the use of non-invasive ventilation and high-flow oxygen therapy with nasal cannulas in adult, pediatric, and neonatal patients with severe acute respiratory failure.

Non-invasive respiratory support (NIRS) in adult, pediatric, and neonatal patients with acute respiratory failure (ARF) comprises two treatment modalities, non-invasive mechanical ventilation (NIMV) and high-flow nasal cannula (HFNC) therapy. However, experts from different specialties disagree on the benefit of these techniques in different clinical settings. The objective of this consensus was to develop a series of good clinical practice recommendations for the application of non-invasive support in patients with ARF, endorsed by all scientific societies involved in the management of adult and pediatric/neonatal patients with ARF. To this end, the different societies involved were contacted, and they in turn appointed a group of 26 professionals with sufficient experience in the use of these techniques. Three face-to-face meetings were held to agree on recommendations (up to a total of 71) based on a literature review and the latest evidence associated with 3 categories: indications, monitoring and follow-up of NIRS. Finally, the experts from each scientific society involved voted telematically on each of the recommendations. To classify the degree of agreement, an analogue classification system was chosen that was easy and intuitive to use and that clearly stated whether the each NIRS intervention should be applied, could be applied, or should not be applied.

Summary of recommendations and key points of the consensus of Spanish scientific societies (SEPAR, SEMICYUC, SEMES; SECIP, SENEO, SEDAR, SENP) on the use of non-invasive ventilation and high-flow oxygen therapy with nasal cannulas in adult, pediatric, and neonatal patients with severe acute respiratory failure. / Sumario de las recomendaciones y puntos clave del Consenso de las Sociedades Científicas Españolas (SEPAR, SEMICYUC, SEMES; SECIP, SENeo, SEDAR, SENP) para la utilización de la ventilación no invasiva y terapia de alto flujo con cánulas nasales en el paciente adulto, pediátrico y neonatal con insuficiencia respiratoria aguda grave.

Non-invasive respiratory support (NIRS) in adult, pediatric, and neonatal patients with acute respiratory failure (ARF) comprises two treatment modalities, non-invasive mechanical ventilation (NIMV) and high-flow nasal cannula (HFNC) therapy. However, experts from different specialties disagree on the benefit of these techniques in different clinical settings. The objective of this consensus was to develop a series of good clinical practice recommendations for the application of non-invasive support in patients with ARF, endorsed by all scientific societies involved in the management of adult and pediatric/neonatal patients with ARF. To this end, the different societies involved were contacted, and they in turn appointed a group of 26 professionals with sufficient experience in the use of these techniques. Three face-to-face meetings were held to agree on recommendations (up to a total of 71) based on a literature review and the latest evidence associated with 3 categories: indications, monitoring and follow-up of NIRS. Finally, the experts from each scientific society involved voted telematically on each of the recommendations. To classify the degree of agreement, an analogue classification system was chosen that was easy and intuitive to use and that clearly stated whether the each NIRS intervention should be applied, could be applied, or should not be applied.

Clinical Consensus Recommendations Regarding Non-Invasive Respiratory Support in the Adult Patient with Acute Respiratory Failure Secondary to SARS-CoV-2 infection. / Recomendaciones de consenso respecto al soporte respiratorio no invasivo en el paciente adulto con insuficiencia respiratoria aguda secundaria a infección por SARS-CoV-2.

Coronavirus disease 2019 (COVID-19) is a respiratory tract infection caused by a newly emergent coronavirus, that was first recognized in Wuhan, China, in December 2019. Currently, the World Health Organization (WHO) has defined the infection as a global pandemic and there is a health and social emergency for the management of this new infection. While most people with COVID-19 develop only mild or uncomplicated illness, approximately 14% develop severe disease that requires hospitalization and oxygen support, and 5% require admission to an intensive care unit. In severe cases, COVID-19 can be complicated by the acute respiratory distress syndrome (ARDS), sepsis and septic shock, and multiorgan failure. This consensus document has been prepared on evidence-informed guidelines developed by a multidisciplinary panel of health care providers from four Spanish scientific societies (Spanish Society of Intensive Care Medicine [SEMICYUC], Spanish Society of Pulmonologists [SEPAR], Spanish Society of Emergency [SEMES], Spanish Society of Anesthesiology, Reanimation, and Pain [SEDAR]) with experience in the clinical management of patients with COVID-19 and other viral infections, including SARS, as well as sepsis and ARDS. The document provides clinical recommendations for the noninvasive respiratory support (noninvasive ventilation, high flow oxygen therapy with nasal cannula) in any patient with suspected or confirmed presentation of COVID-19 with acute respiratory failure. This consensus guidance should serve as a foundation for optimized supportive care to ensure the best possible chance for survival and to allow for reliable comparison of investigational therapeutic interventions as part of randomized controlled trials.

[Is postoperative acute pain control in colorectal surgery better within an enhanced recovery after surgery program (ERAS)?] / ¿Mejora el control del dolor postoperatorio en cirugía colorrectal tras la implementación de un protocolo de rehabilitación intensificada (ERAS)?

BACKGROUND AND OBJECTIVE: A good acute pain control is necessary to achieve the main objective of Enhanced recovery After Surgery (ERAS) programs and accelerate recovery. The study objective is to evaluate postoperative (PO) acute pain, PO opioid consumption, and its association with functional recovery, after implementing a colorectal surgery ERAS program. An analysis was made as regards drugs adverse effects. METHODS: Observational cohort study on scheduled colorectal Surgery: one prospective cohort subjected to the ERAS care program, and one retrospective cohort that received traditional non-standardised care. A record was made of mean pain intensity (measured by a visual analogue scale, which classifies pain intensity from 0 to 10, from lower to higher intensity), as well as the amount of opioid consumption on the day of surgery and on the first three postoperative days, and drugs adverse effects. An analysis was made of the association between PO opioid consumption and ERAS program, and between PO opioid consumption and functional recovery. RESULTS: The study included a total of 410 patients (313 in the ERAS group and 97 in the control group). In the ERAS group, it was observed that the mean visual analogue scale was less than 2, with a smaller amount of PO opioid consumption, on each single day and the accumulated amount of the four days (4 [0-24] vs. 0 [0-4], P<.001). PO opioid consumption was associated with functional recovery (OR 0.97 [95% CI; 0.96-0.99], P=.011). No drugs adverse effects were observed. CONCLUSIONS: After implementing a colorectal Surgery ERAS program, good pain control was achieved, as well as a reduction in PO opioid consumption, which is associated with functional recovery. No drugs adverse effects were observed.

Mixotrophy in marine picocyanobacteria: use of organic compounds by Prochlorococcus and Synechococcus.

Marine picocyanobacteria of the Prochlorococcus and Synechococcus genera have been longtime considered as autotrophic organisms. However, compelling evidence published over the last 15 years shows that these organisms can use different organic compounds containing key elements to survive in oligotrophic oceans, such as N (amino acids, amino sugars), S (dimethylsulfoniopropionate, DMSP), or P (ATP). Furthermore, marine picocyanobacteria can also take up glucose and use it as a source of carbon and energy, despite the fact that this compound is devoid of limiting elements and can also be synthesized by using standard metabolic pathways. This review will outline the main findings suggesting mixotrophy in the marine picocyanobacteria Prochlorococcus and Synechococcus, and its ecological relevance for these important primary producers.

Mannose-coated polydiacetylene (PDA)-based nanomicelles: synthesis, interaction with concanavalin A and application in the water solubilization and delivery of hydrophobic molecules.

Carbohydrate-lectin interactions are involved in a number of relevant biological events including fertilization, immune response, cell adhesion, tumour cell metastasis, and pathogen infection. Lectins are also tissue specific, making carbohydrates not only promising drug candidates but also excellent low molecular weight ligands for active drug delivery system decorations. In order for these interactions to be effective multivalency is essential, as the interaction of a lectin with its cognate monovalent carbohydrate epitope usually takes place with low affinity. Unlike the covalent approach, supramolecular self-assembly of glyco-monomers mediated by non-covalent forces allows accessing multivalent systems with diverse topology, composition, and assembly dynamics in a single step. In order to fine-tune the size and sugar adaptability of spherical micelles at the nanoscale for an optimal glycoside cluster effect, herein we report the synthesis of mannose-coated static micelles from diacetylene-based mannopyranosyl glycolipids differing in the length of the poly(ethyleneglycol) (PEG) chains and the oxidation state of the anomeric sulfur atom. The reported shot-gun like synthetic approach for the synthesis of dilution-insensitive micelles is based on the ability of diacetylenic-based neoglycolipids to self-assemble into micelles in water and to undergo an easy photopolymerization by a simple irradiation at 254 nm. The affinity of the obtained 6 nanosystems was assessed by enzyme-linked lectin assay (ELLA) using the mannose-specific concanavalin A lectin as a model receptor. Relative binding potency enhancements, compared to methyl α-d-mannopyranoside used as control, from 20-, to 29- to 300-fold on a sugar molar basis were observed for micelles derived from sulfonyl-, sulfinyl- and thioglycoside monomers with a tatraethyleneglycol spacer, respectively, indicative of a significant cluster glycoside effect. Moreover, pMic1 micelles are able to solubilize and slowly liberate lipophilic clinically relevant drugs, and show the enhanced cytotoxic effect of docetaxel toward prostate cancer cells. These findings highlight the potential of mannose-coated photopolymerized micelles pMic1 as an efficient nanovector for active delivery of cytotoxic hydrophobic molecules.

Development of a Novel Imaging Agent for Determining Albumin Uptake in Solid Tumors.

PURPOSE: The purpose of this study was to investigate the albumin-binding compound 111In-C4-DTPA as an imaging agent for the detection of endogenous albumin accumulation in tumors. METHODS: 111In-C4-DTPA was injected in healthy nude mice for pharmacokinetic and biodistribution studies (10 min, 1, 6, 24, and 48 h, n = 4) and subsequently in tumor-bearing mice for single-photon emission computed tomography/X-ray-computed tomography (SPECT/CT) imaging studies. Four different human tumor xenograft models (LXFL529, OVXF899, MAXFTN401, and CXF2081) were implanted subcutaneously unilaterally or bilaterally (n = 4-8). After intravenous administration of 111In-C4-DTPA, SPECT/CT images were collected over 72 h at 4-6 time points. Additionally, gamma counting was performed for the blood, plasma, lungs, heart, liver, spleen, kidneys, muscle, and tumors at 72 h post-injection. RESULTS: 111In-C4-DTPA bound rapidly to circulating albumin upon injection, and the radiolabeled albumin conjugate thus formed was stable in murine and human serum. SPECT/CT images demonstrated a time-dependent uptake with a maximum of 2.7-3.8% ID/cm3 in the tumors at approximately 24 h post-injection and mean tumor/muscle ratios in the range of 3.2-6.2 between 24 and 72 h post-injection. The kidneys and bladder were the predominant elimination organs. Gamma counting at 72 h post-injection showed 1.3-2.5% ID/g in the tumors and mean tumor/muscle ratios in the range of 4.9-9.4. CONCLUSION: 111In-C4-DTPA bound rapidly to circulating albumin upon injection and showed time-dependent uptake in the tumors demonstrating a potential for clinical application as a companion imaging diagnostic for albumin-binding anticancer drugs.