Burnout, moral injury, and suicidal/self-harm ideation among healthcare professionals in Mainland China: Insights from an online survey during the COVID-19 pandemic.

OBJECTIVE: This survey aimed to explore the relationships between burnout, moral injury, and suicidal/self-harm ideation among Chinese health professionals to provide a reference for protecting their mental health. METHOD: Health professionals were surveyed online using the Maslach Burnout Inventory-Human Services Survey for Medical Personnel, Patient Health Questionnaire-9, and the Moral Injury Symptoms Scale-Health Professional. RESULTS: In the analysis, 6146 eligible respondents were included in the study. The average participant age was 34.9 ± 8.5 years, and suicidal/self-harm ideation was detected in 2338 participants (38.0%). The prevalence of suicidal/self-harm ideation among those with severe burnout in the dimensions of emotional exhaustion, depersonalisation, and decreased personal accomplishment was significantly higher than those with mild burnout. The prevalence of suicidal/self-harm ideation among those with significant moral injury symptoms was higher than those without moral injury. Unconditional logistic regression analysis showed that those with moderate or severe emotional exhaustion, moderate or severe reduced sense of professional accomplishment and moderate or severe depersonalisation had increased risks of suicidal/self-harm ideation. CONCLUSIONS: Structural equation modelling demonstrated that burnout significantly mediated the relationship between moral injury and suicidal/self-harm ideation. The proportion of mediation (PM) by burnout was 43.0%. Burnout and moral injury were potential predictors of suicidal/self-harm ideation among health professionals. Both moral injury and burnout had positive and direct effects on suicidal/self-harm ideation, and burnout was a mediator in this relationship among Chinese health professionals. Therefore, to alleviate the moral injury and subsequent burnout of healthcare workers and enhance their mental qualities, active interventions should be developed in the future.

Extensive Characterization of Polysorbate 80 Oxidative Degradation Under Stainless Steel Conditions.

Polysorbate-80 (PS-80) is a common surfactant used in biologics formulations. However, the tendency of oxidation to PS-80 when exposed to stainless steel surfaces brings various challenges during manufacturing processes, such as inconsistent shelf-life of PS-80 solutions, which can further impact the biologics and vaccines production. In this work, the root causes of PS-80 oxidation when in contact with stainless steel conditions were thoroughly investigated through the use of various complementary analytical techniques including U/HPLC-CAD, LC-MS, ICP-MS, peroxide assay, and EPR spectroscopy. The analytical tool kit used in this work successfully revealed a PS-80 degradation mechanism from the perspective of PS-80 content, PS-80 profile, iron content, peroxide production, and radical species. The combined datasets reveal that PS-80 oxidative degradation occurs in the presence of histidine and iron in addition to being combined with the hydroperoxides in PS-80 material. The oxidative pathway and potential degradants were identified by LC-MS. The PS-80 profile based on the U/HPLC-CAD assay provided an effective way to identify early-signs of PS-80 degradation. The results from a peroxide assay observed increased hydroperoxide along with PS-80 degradation. EPR spectra confirmed the presence of histidine-related radicals during PS-80 oxidation identifying how histidine is involved in the oxidation. All assays and findings introduced in this work will provide insight into how PS-80 oxidative degradation can be avoided, controlled, or detected. It will also provide valuable evaluations on techniques that can be used to identify PS-80 degradation related events that occur during the manufacturing process.

Dynamic changes in the migratory microbial components of colon tissue during different periods of sepsis in an LPS-induced rat model.

Previous studies have shown that bacterial translocation may play an important role in worsening gastrointestinal injury during sepsis. However, the dynamics of specific microbiota components in intestinal tissues at different sepsis stages remain unclear. Rats receiving intraperitoneal lipopolysaccharide (LPS) were sacrificed at 12 h and 48 h post-injection. Routine blood, serum cytokines, and microbiota in colon tissue, colonic contents, and lung tissue at different time points were assessed. Migratory microbial components in colonic tissue at 12 h and 48 h post-LPS were identified using source tracking, characteristic component identification, and abundance difference analyses. Colonic tissue microbiota changed dynamically over time after LPS injection, involving translocation of microbial components from colon contents and lung tissue at different time points. Bacteria migrating to colon tissue at 12 h sepsis were mainly from colonic contents, while those at 48 h were predominantly from the lung tissue. The migratory microbial components in colon tissue were widely associated with blood indicators and colonizing genus abundance and microbiota functionality in colon tissue. In this study, the temporal dynamics of bacterial translocation from various sources into colon tissues at different sepsis progression stages were characterized for the first time, and the species composition of these migrating microbes was delineated. These bacterial migrants may contribute to the pathophysiological processes in sepsis through direct interactions or indirectly by modulating colonic microbiota community structure and function.

Reduced frequencies of Foxp3+GARP+ regulatory T cells in COPD patients are associated with multi-organ loss of tissue phenotype.

BACKGROUND: Expression of glycoprotein A dominant repeat (GARP) has been reported to occur only in activated human naturally occurring regulatory T cells (Tregs) and their clones, and not in activated effector T cells, indicating that GARP is a marker for bona fide Tregs. A different phenotype of chronic obstructive pulmonary disease (COPD) may have a different immunologic mechanism. OBJECTIVE: To investigate whether the distribution of Tregs defined by GARP is related to the multi-organ loss of tissue phenotype in COPD. METHODS: GARP expression on T cells from peripheral blood and bronchoalveolar lavage (BAL) collected from patients with COPD was examined by flow cytometry. The correlation of GARP expression to clinical outcomes and clinical phenotype, including the body mass index, lung function and quantitative computed tomography (CT) scoring of emphysema, was analyzed. RESULTS: Patients with more baseline emphysema had lower forced expiratory volume, body mass index (BMI), worse functional capacity, and more osteoporosis, thus, resembling the multiple organ loss of tissue (MOLT) phenotype. Peripheral Foxp3+GARP+ Tregs are reduced in COPD patients, and this reduction reversely correlates with quartiles of CT emphysema severity in COPD. Meanwhile, the frequencies of Foxp3+GARP- Tregs, which are characteristic of pro-inflammatory cytokine production, are significantly increased in COPD patients, and correlated with increasing quartiles of CT emphysema severity in COPD. Tregs in BAL show a similar pattern of variation in peripheral blood. CONCLUSION: Decreased GARP expression reflects more advanced disease in MOLT phenotype of COPD. Our results have potential implications for better understanding of the immunological nature of COPD and the pathogenic events leading to lung damage.

Applications of Surface Plasmon Resonance and Biolayer Interferometry for Virus-Ligand Binding.

Surface plasmon resonance and biolayer interferometry are two common real-time and label-free assays that quantify binding events by providing kinetic parameters. There is increased interest in using these techniques to characterize whole virus-ligand interactions, as the methods allow for more accurate characterization than that of a viral subunit-ligand interaction. This review aims to summarize and evaluate the uses of these technologies specifically in virus-ligand and virus-like particle-ligand binding cases to guide the field towards studies that apply these robust methods for whole virus-based studies.

Dynamic alterations in the lung microbiota in a rat model of lipopolysaccharide-induced acute lung injury.

The lung microbiota have been found to be substantially altered in numerous pulmonary disorders, and crosstalk between the host pathophysiology and lung microbiota plays critical roles in the regulation of disease states. The aim of this study was to investigate dynamic changes in the lung microbiota during different stages of acute lung injury and acute respiratory distress syndrome (ALI/ARDS). Rats receiving an intraperitoneal administration of lipopolysaccharide (LPS) were sacrificed at 12 and 48 h after injection, and the hematological parameters, serum cytokine levels, and histological characteristics of the lung tissue and lung microbiota were assessed. After LPS injection, along with fluctuations of systemic cytokine levels and the onset and regression of pulmonary edema, the diversity, components, and functionalities of the pulmonary microbiota underwent significant dynamic changes. The volatility of the α-diversity indices narrowed after LPS injection, and the indices significantly decreased 48 h later. The abundance of 18 genera and functionality of adenosine triphosphate-binding cassette (ABC) transporters, pentose phosphate, and bacterial chemotaxis pathways were found to significantly differ between specified time points. Several significant correlations between the components and functionalities of the lung microbiota and indicative symptoms of ALI/ARDS were also observed. Brevibacterium was correlated with cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-10, and IL-6 and with hematological percentage of neutrophils (NEU%); Wnt, Notch, and chronic myeloid leukemia signaling pathways were correlated with IL-1ß; mitogen-activated protein kinase (MAPK) signaling pathway-yeast was correlated with IL-10; and the pathways of ascorbate and aldarate metabolism and basal transcription factors were correlated with platelet-related indicators. The correlations between the lung microbiota and indicative symptoms of ALI/ARDS identified in this study support further investigation into the underlying mechanism of host-microbiota interactions during lung injury and repair.

Complete regression of pulmonary squamous carcinoma in IPF following gemcitabine plus cisplatin: a case report and literature review.

BACKGROUND: Lung cancer is one of the most common co-morbid conditions in patients with idiopathic pulmonary fibrosis (IPF) and negatively affects the prognosis of IPF; Current guidelines for the management of IPF do not give a clear statement on how to manage these patients, and traditional chemotherapy for lung cancer had a limited efficiency rate. Here, we present a rare case of primary lung squamous carcinoma in a patient with IPF whose tumor completely regressed following gemcitabine plus cisplatin therapy; the cancer was no longer detectable after 2 years upon follow-up. CASE PRESENTATION: Sixty-seven year-old male patient with IPF was admitted to hospital due to acute onset hemoptysis. In addition to a definite usual interstitial pneumonia (UIP) pattern, a chest CT scan showed a non-enhancing nodular opacity in the right upper lobe and an enhancing nodule in the right lower lobe. Bronchoscopic biopsy of the nodule in the right lower lobe revealed squamous lung cancer. After 2 cycles of chemotherapy with gemcitabine and cisplatin, the tumor in the right lower lobe was no longer detectable after 2 years of follow-up; however, the nodule in the right upper lobe had increased significantly. Finally, Mycobacterium tuberculosis (MTB) was cultured from the bronchoalveolar (BAL) sample submitted at the last evaluation, and the patient was confirmed to have active pulmonary TB. CONCLUSION: We report the first documented case of complete pulmonary squamous carcinoma regression in IPF following gemcitabine plus cisplatin. Traditional chemotherapy is considered inadequate to cause the resulting regression of the tumor. The concomitant active pulmonary tuberculosis possibly underlies the mechanism.

[Clinical efficacy and safety of different antiviral regimens in patients with coronavirus disease 2019].

OBJECTIVE: To investigate the clinical efficacy and short-term and long-term adverse reactions for different antiviral regiments for coronavirus disease 2019 (COVID-19) in Ningxia Hui Autonomous Region during hospitalization and follow-up in 3 months. METHODS: A single-center retrospective study was conducted to enroll the COVID-19 patients in isolation ward of the only designated hospital to receive COVID-19 patients (the Fourth People's Hospital of Ningxia Hui Autonomous Region) when the authors were assigned by the Ningxia Health Commission as experts from January 20, 2020 to March 15, 2020. According to the antiviral regimen, the patients were divided into conventional antiviral group and unconventional antiviral group. The conventional antiviral group received α-interferon combined with Lopinavir/Ritonavir (LPV/R). The unconventional antiviral group was given α-interferon combined with LPV/R and Abidor or Ribavirin or Chloroquine. The patients were divided into mild (13 cases), ordinary (45 cases), severe (14 cases) and critical (1 case) types. The clinical data, length of hospital stay, the first 2019 novel coronavirus (2019-nCoV) nucleic acid negative recovery time, cost of hospitalization, 2019-nCoV nucleic acid positive reversal after 14 days of discharge, and the combination of hormones and antibiotics were collected. The differences in blood routine, liver function, blood lipid level and adverse reactions of antiviral drugs during hospitalization were compared between the two groups at 1, 3 and 7 days after admission and 1 and 3 months after discharge. RESULTS: (1) General information: a total of 75 patients with confirmed COVID-19 were admitted, and 73 patients were eventually enrolled, including 47 cases in the conventional antiviral group and 26 cases in the unconventional antiviral group. Patients with different clinical classification were analyzed, the higher the clinical classification and the patients' age, the higher the proportion of primary diseases and the cost of treatment, and the longer the length of hospital stay. Compared with conventional antiviral group, in unconventional antiviral group the percentage of severe and critical patients were higher [34.6% (9/26) vs. 10.6% (5/47), 3.8% (1/26) vs. 0 (0/47)], the length of hospital stay (days: 16.1±5.6 vs. 11.6±3.3), first nucleic acid negative recovery time (days: 12.4±4.5 vs. 10.0±3.5) were longer, and hospitalization cost was higher [Yuan: 11 984.2 (9 000.6, 24 424.7) vs. 8 140.4 (6 715.7,9 707.7)], with statistically significant differences (all P < 0.05). There were no significant differences in gender, age, proportion of patients with primary diseases and nucleic acid positive reversal rate after 14 days of discharge between the unconventional and conventional antiviral groups (all P > 0.05). (2) Laboratory tests: during the hospitalization, white blood cell count (WBC), platelet count (PLT), total bilirubin (TBil) and three acyl glycerin (TG) levels were first increased and then reduced, lymphocyte count (LYM) was first decreased and then increased in two groups. In the unconventional antiviral group, WBC [(6.53±2.78)×109/L], PLT [(250.77±96.12)×109/L], and TG [(1.94±0.96) µmol/L] all reached their peak values at 7 days after admission. TBil peaked at 3 days after admission, which was (23.69±12.14) µmol/L, and LYM reached the peak 1 month after discharge, which was (1.82±0.50)×109/L; however, there was no statistical significance among the above indicators between two groups. There were no statistically significant differences in alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total cholesterol (TC) between the two groups at each time point. (3) The ratio of combined use of hormones in the non-antiviral group was significantly higher than that in the conventional antiviral group [26.9% (7/26) vs. 4.3% (2/47), P < 0.05]. CONCLUSIONS: Age and associated primary diseases are related to the severity of COVID-19 patients. Unconventional antiviral treatment regimens are mostly used for severe COVID-19 patients whose ucleic acid did not turn negative for a long time. Individual antiviral therapy can be used based on the patients' response and tolerance to drugs.

Correction to: Analysis of glipizide binding to normal and glycated human serum albumin by high-performance affinity chromatography.

The authors would like to call the reader's attention to the following corrections in this article. In the description given for the process of preparing glycated human serum albumin under "In vitro glycation of HSA", the concentrations of D-glucose that were employed were 15 mM and 30 mM.

Binding studies based on ultrafast affinity extraction and single- or two-column systems: Interactions of second- and third-generation sulfonylurea drugs with normal or glycated human serum albumin.

Ultrafast affinity extraction was evaluated and used with microcolumns containing human serum albumin (HSA) to measure the global affinity constants and dissociation rate constants for several second- and third-generation sulfonylurea drugs with solution-phase normal HSA or glycated HSA. Glibenclamide, glimepiride and glipizide were used as model drugs for this work. Both single- and two-column systems were considered for the analysis of global affinities for the model drugs. These methods were optimized with respect to the flow rates, column sizes and sample residence times that were employed with each drug for ultrafast affinity extraction. Data acquired with single-column systems were further utilized to estimate the dissociation rate constants for normal HSA and glycated HSA with the given drugs. The binding constants obtained by the single- and two-column systems showed good agreement with each other and with values obtained from the literature. Use of a single-column system indicated that levels of glycation found in controlled or advanced diabetes resulted in a 18-44% decrease in the overall binding strength of the model drugs with HSA. Although the two-column system allowed work with smaller free drug fractions and clinically-relevant drug/protein concentrations, the single-column system required less protein, provided better precision, and was easier to use in binding studies.

Increased pro-inflammatory cytokine-secreting regulatory T cells are correlated with the plasticity of T helper cell differentiation and reflect disease status in asthma.

BACKGROUND: Human regulatory T cells (Tregs) are a heterogeneous population which consists of three distinct subpopulations: CD25+CD45RA+ resting Treg (rTreg) cells; CD25hiCD45RA- activated Treg (aTreg) cells, which are both suppressive; and CD25+CD45RA- cytokine-secreting T cells with pro-inflammatory capacity. OBJECTIVE: We investigated variation in peripheral Treg subpopulations of asthma and explored their potential roles in asthma inflammation. METHODS: Twenty-eight mild asthma patients, 26 moderate asthma patients, 18 severe asthma patients, and 36 healthy controls were recruited for a cross-sectional study. Phenotyping of peripheral CD4+ Tregs was performed based on flow cytometry results. RESULTS: The proportions of rTreg and aTreg cells among CD4+ T cells were higher in mild and moderate asthma patients than in healthy controls. All three groups of asthmatics had a higher proportion of pro-inflammatory Tregs than healthy controls, and these increased with asthma severity. The proportion of IL-17-producing Foxp3+ cells and IFN-ɤ-producing Foxp3+ cells strongly correlated with T helper 17 (Th17) cells (r = 0.66, p < 0.001) and Th1 cells (r = 0.48, p < 0.001). The pro-inflammatory Treg subpopulation was correlated with the severity of asthma and may be insensitive to corticosteroids. CONCLUSIONS: Our data suggest that pro-inflammatory Treg subpopulations may be relevant to the plasticity of Th17 and Th1 differentiation and play an important role in the pathogenesis of asthma.

Characterization of solution-phase drug-protein interactions by ultrafast affinity extraction.

A number of tools based on high-performance affinity separations have been developed for studying drug-protein interactions. An example of one recent approach is ultrafast affinity extraction. This method has been employed to examine the free (or non-bound) fractions of drugs and other solutes in simple or complex samples that contain soluble binding agents. These free fractions have also been used to determine the binding constants and rate constants for the interactions of drugs with these soluble agents. This report describes the general principles of ultrafast affinity extraction and the experimental conditions under which it can be used to characterize such interactions. This method will be illustrated by utilizing data that have been obtained when using this approach to measure the binding and dissociation of various drugs with the serum transport proteins human serum albumin and alpha1-acid glycoprotein. A number of practical factors will be discussed that should be considered in the design and optimization of this approach for use with single-column or multi-column systems. Techniques will also be described for analyzing the resulting data for the determination of free fractions, rate constants and binding constants. In addition, the extension of this method to complex samples, such as clinical specimens, will be considered.

Notch promotes DNMT-mediated hypermethylation of Klotho leads to COPD-related inflammation.

AIM: Klotho expression significantly declines in alveolar macrophages and airway epithelial cells in chronic obstructive pulmonary disease (COPD) patients, and cigarette smoke extract dramatically inhibits the expression and secretion of α-Klotho. This suggests that the silencing of Klotho is the major factor promoting COPD related inflammatory responses. This study aims to investigate the mechanism of Klotho downregulation and its effect on the inflammatory cytokines secretion and cell apoptosis. METHODS: Expression of DNA methyltransferases (DNMTs) and Notch signaling activation were quantified in MH-S and 16HBE cells stimulated with cigarette smoke extract (CSE) solution. Specific inhibitors of DNMTs or Notch pathway were added together with CSE into treated and control cells. Inflammatory cytokines, cell viability and cell death were determined to explore the effect of Klotho on COPD related inflammation. RESULTS: CSE treatment statistically increased the level of DNMTs expression, Klotho promoter methylation, and activated the Notch signaling pathway. Notch signal activation played a critical role in the process of modification of Klotho promoter methylation. The inhibition of DNMTs and Notch pathway rescued Klotho levels and inhibited inflammation and cell apoptosis after CSE treatment. CONCLUSION: Notch-mediated Klotho hypermethylation inhibited Klotho expression, which promoted inflammatory response and cell apoptosis that were associated with the development of COPD.

High performance affinity chromatography and related separation methods for the analysis of biological and pharmaceutical agents.

The last few decades have witnessed the development of many high-performance separation methods that use biologically related binding agents. The combination of HPLC with these binding agents results in a technique known as high performance affinity chromatography (HPAC). This review will discuss the general principles of HPAC and related techniques, with an emphasis on their use for the analysis of biological compounds and pharmaceutical agents. Various types of binding agents for these methods will be considered, including antibodies, immunoglobulin-binding proteins, aptamers, enzymes, lectins, transport proteins, lipids, and carbohydrates. Formats that will be discussed for these methods range from the direct detection of an analyte to indirect detection based on chromatographic immunoassays, as well as schemes based on analyte extraction or depletion, post-column detection, and multi-column systems. The use of biological agents in HPLC for chiral separations will also be considered, along with the use of HPAC as a tool to screen or study biological interactions. Various examples will be presented to illustrate these approaches and their applications in fields such as biochemistry, clinical chemistry, and pharmaceutical research.

Primary ciliary dyskinesia presenting with spontaneous pneumothorax: Case report and review of the literature.

BACKGROUND: Primary ciliary dyskinesia (PCD) is an autosomal recessive heterogeneous group of conditions with variable clinical findings. CASE PRESENTATION: A 36-year-old nonsmoking Chinese man present to the emergency department of our hospital with acute-onset breathlessness and sudden-onset left-sided chest pain. The patient had 6 years primary infertility and suffered from recurrent episodes of respiratory tract infections since childhood. Chest X-ray was performed, which showed a left-sided pneumothorax with lung collapse. His conditions improved in clinical symptoms after 3 days of closed thoracic drainage. Radiographic findings after lung recruitment revealed bronchiectasis and bronchiolitis but no situs inversus. Paranasal sinus computed tomography (CT) showed maxillary sinusitis and ethmoid sinusitis. Pulmonary function tests demonstrated severe obstructive ventilation functional impairment. Bronchial mucosal cilia showed the absence of both outer and inner dynein arms of the microtubules (ODA and IDA). A culture of bronchoalveolar lavage fluid was positive for Pseudomonas aeruginosa. His clinical symptoms and CT images showed improvement after 1 month of treatment. A literature review revealed that few patients are diagnosed with PCD complicated with spontaneous pneumothorax. Within one year of follow-up, the patient showed good responses to local ICS+ LA beta2 agonist combined with oral carbocistein. CONCLUSIONS: Pneumothorax might be one of the complications of the PCD. Combination therapy including ICS+ LA beta2 agonist and carbocistein could be a potential therapy to reduce the frequency of acute exacerbations and delay progression of PCD.

Chromatographic studies of drug interactions with alpha1-acid glycoprotein by ultrafast affinity extraction and peak profiling.

Interactions with serum proteins such as alpha1-acid glycoprotein (AGP) can have a significant effect on the behavior and pharmacokinetics of drugs. Ultrafast affinity extraction and peak profiling were used with AGP microcolumns to examine these processes for several model drugs (i.e., chlorpromazine, disopyramide, imipramine, lidocaine, propranolol and verapamil). The association equilibrium constants measured for these drugs with soluble AGP by ultrafast affinity extraction were in the general range of 104-106M-1 at pH 7.4 and 37°C and gave good agreement with literature values. Some of these values were dependent on the relative drug and protein concentrations that were present when using a single-site binding model; these results suggested a more complex mixed-mode interaction was actually present, which was also then used to analyze the data. The apparent dissociation rate constants that were obtained by ultrafast affinity extraction when using a single-site model varied from 0.14 to 7.0s-1 and were dependent on the relative drug and protein concentrations. Lower apparent dissociation rate constants were obtained by this approach as the relative amount of drug versus protein was decreased, with the results approaching those measured by peak profiling at low drug concentrations. This information should be useful in better understanding how these and other drugs interact with AGP in the circulation. In addition, the chromatographic approaches that were optimized and used in this report to examine these systems can be adapted for the analysis of other solute-protein interactions of biomedical interest.

Dual-Target Binding Ligands with Modulated Pharmacokinetics for Endoradiotherapy of Prostate Cancer.

Prostate-specific membrane antigen (PSMA)-targeted radiotherapy of prostate cancer (PCa) has emerged recently as a promising approach to the treatment of disseminated disease. A small number of ligands have been evaluated in patients, and although early tumor response is encouraging, relapse rate is high and these compounds localize to the parotid, salivary, and lacrimal glands as well as to the kidney, leading to dose-limiting toxicities and adverse events affecting quality of life. We envision that dual-target binding ligands displaying high affinity for PSMA and appropriate affinity for human serum albumin (HSA) may demonstrate a higher therapeutic index and be suitable for treatment of PCa by targeted α-therapy. Methods: Six novel urea-based ligands with varying affinities for PSMA and HSA were synthesized, labeled with 131I, and evaluated by in vitro binding and uptake assays in LNCaP cells. Four compounds were advanced for further evaluation in a preclinical model of PCa. The compounds were compared with MIP-1095, a PSMA ligand currently in clinical evaluation. Results: The compounds demonstrated affinity for PSMA on the order of 4-40 nM and affinity for HSA in the range of 1-53 µM. Compounds with relatively high affinity for HSA (≤2 µM) showed high and sustained blood-pool activity and reduced uptake in the kidneys. 131I-RPS-027, with a 50% inhibitory concentration (PSMA) of 15 nM and a dissociation constant (HSA) of 11.2 µM, cleared from the blood over the course of 48 h and showed good tumor uptake (10 percentage injected dose per gram) and retention and a greater than 5-fold decrease in kidney uptake relative to MIP-1095. The tumor-to-kidney ratio of 131I-RPS-027 was greater than 3:1 at 24 h after injection, increasing to 7:1 by 72 h. Conclusion: RPS-027 shows dual targeting to PSMA and albumin, resulting in a high tumor uptake, highly favorable tissue distribution, and promising therapeutic profile in a preclinical model of prostate cancer. In comparison to existing ligands proposed for targeted therapy of prostate cancer, RPS-027 has tumor-to-tissue ratios that predict a significant reduction in side effects during therapy. Using iodine/radioiodine as a surrogate for the radiohalogen 211At, we therefore propose dual-target binding ligands such as RPS-027 as next-generation radiopharmaceuticals for targeted α-therapy using 211At.

High-Performance Affinity Chromatography: Applications in Drug-Protein Binding Studies and Personalized Medicine.

The binding of drugs with proteins and other agents in serum is of interest in personalized medicine because this process can affect the dosage and action of drugs. The extent of this binding may also vary with a given disease state. These interactions may involve serum proteins, such as human serum albumin or α1-acid glycoprotein, or other agents, such as lipoproteins. High-performance affinity chromatography (HPAC) is a tool that has received increasing interest as a means for studying these interactions. This review discusses the general principles of HPAC and the various approaches that have been used in this technique to examine drug-protein binding and in work related to personalized medicine. These approaches include frontal analysis and zonal elution, as well as peak decay analysis, ultrafast affinity extraction, and chromatographic immunoassays. The operation of each method is described and examples of applications for these techniques are provided. The type of information that can be obtained by these methods is also discussed, as related to the analysis of drug-protein binding and the study of clinical or pharmaceutical samples.

Analysis of free drug fractions in serum by ultrafast affinity extraction and two-dimensional affinity chromatography using α1-acid glycoprotein microcolumns.

In the circulatory system, many drugs are reversibly bound to serum proteins such as human serum albumin (HSA) and alpha1-acid glycoprotein (AGP), resulting in both free and protein-bound fractions for these drugs. This report examined the use of microcolumns containing immobilized AGP for the measurement of free drug fractions by ultrafast affinity extraction and a two-dimensional affinity system. Several drugs known to bind AGP were used as models to develop and evaluate this approach. Factors considered during the creation of this method included the retention of the drugs on the microcolumns, the injection flow rate, the microcolumn size, and the times at which a second AGP column was placed on-line with the microcolumn. The final system had residence times of only 110-830ms during sample passage through the AGP microcolumns and allowed free drug fractions to be determined within 10-20min when using only 3-10µL of sample per injection. This method was used to measure the free fractions of the model drugs at typical therapeutic levels in serum, giving good agreement with the results obtained by ultrafiltration. This approach was also used to estimate the binding constants for each drug with AGP in serum, even for drugs that had significant interactions with both AGP and HSA in such samples. These results indicated that AGP microcolumns could be used with ultrafast affinity extraction to measure free drug fractions in a label-free manner and to study the binding of drugs with AGP in complex samples such as serum.