Chemotherapy combined with immune checkpoint inhibitors may overcome the detrimental effect of high neutrophil-to-lymphocyte ratio prior to treatment in esophageal cancer patients.

Introduction: Immune checkpoint inhibitors (ICIs) have emerged as a promising treatment option for esophageal cancer (EC). Although ICIs enable long-term survival in some patients, the efficacy of ICIs varies widely among patients. Therefore, predictive biomarkers are necessary for identifying patients who are most likely to benefit from ICIs to improve the efficacy of the treatment. We retrospectively analyzed the outcomes of combination therapy, including nivolumab plus ipilimumab or chemotherapy plus anti-programmed cell death 1 (PD-1) antibodies in our institute to identify biomarkers. Methods: Twenty-seven patients received nivolumab plus ipilimumab, and thirty-six patients received chemotherapy plus anti-PD-1 antibodies were included in this study. We analyzed patient characteristics, efficacy, and safety. Multivariable analysis of biomarkers evaluated the correlation among overall survival (OS), progression-free survival (PFS), and the following variables: body mass index, performance status, neutrophil-to-lymphocyte ratio (NLR), C-reactive protein level, and albumin level before treatment. Results: In multivariable analysis, albumin level was significantly correlated with PFS in the cisplatin plus 5-fluorouracil (CF) plus pembrolizumab group. NLR and albumin level were significantly correlated with OS in the nivolumab plus ipilimumab group. Other variables, including PS, BMI, and CRP did not correlate with any of the outcomes. Conclusions: High NLR in EC patients prior to treatment was significantly less effective for ICIs. In chemotherapy combined with ICIs, NLR before the treatment was not associated with treatment efficacy, suggesting combination chemotherapy may be beneficial for EC patients with high NLR. NLR may be an indicator of immunocompetence in anti-tumor immunity and a convenient predictive biomarker for selecting appropriate treatments including ICIs.

Usefulness of an Artificial Intelligence Model in Recognizing Recurrent Laryngeal Nerves During Robot-Assisted Minimally Invasive Esophagectomy.

BACKGROUND: Recurrent laryngeal nerve (RLN) palsy is a common complication in esophagectomy and its main risk factor is reportedly intraoperative procedure associated with surgeons' experience. We aimed to improve surgeons' recognition of the RLN during robot-assisted minimally invasive esophagectomy (RAMIE) by developing an artificial intelligence (AI) model. METHODS: We used 120 RAMIE videos from four institutions to develop an AI model and eight other surgical videos from another institution for AI model evaluation. AI performance was measured using the Intersection over Union (IoU). Furthermore, to verify the AI's clinical validity, we conducted the two experiments on the early identification of RLN and recognition of its location by eight trainee surgeons with or without AI. RESULTS: The IoUs for AI recognition of the right and left RLNs were 0.40 ± 0.26 and 0.34 ± 0.27, respectively. The recognition of the right RLN presence in the beginning of right RLN lymph node dissection (LND) by surgeons with AI (81.3%) was significantly more accurate (p = 0.004) than that by surgeons without AI (46.9%). The IoU of right RLN during right RLN LND recognized by surgeons with AI (0.59 ± 0.18) was significantly higher (p = 0.010) than that by surgeons without AI (0.40 ± 0.29). CONCLUSIONS: Surgeons' recognition of anatomical structures in RAMIE was improved by our AI system with high accuracy. Especially in right RLN LND, surgeons could recognize the RLN more quickly and accurately by using the AI model.

Long-Term Outcomes of Carbon Dioxide Insufflation in Thoracoscopic Esophagectomy After Neoadjuvant Chemotherapy for Esophageal Squamous Cell Carcinoma: A Retrospective Cohort Study.

BACKGROUND: Thoracoscopic esophagectomy (TE) with carbon dioxide (CO2) insufflation is increasingly performed for esophageal cancer; however, there is limited evidence of the long-term outcomes of CO2 insufflation on postoperative survival. OBJECTIVES: We investigated the long-term outcomes of TE with or without CO2 insufflation. METHODS: We enrolled 182 patients who underwent TE for esophageal cancer between January 2003 and October 2013 and categorized them into two groups: with and without CO2 insufflation. The primary endpoint was five-year overall survival (5y-OS). Secondary endpoints included long-term outcomes, such as five-year relapse-free survival (5y-RFS) and five-year cancer-specific survival (5y-CSS), and short-term outcomes, such as surgical and non-surgical complications and reoperation within 30 days. RESULTS: Follow-up until death or the five-year postoperative period was 98.9% (median follow-up duration was six years in survivors). After adjusting for age, sex, and yield pathologic tumor, node, and metastasis (TNM) stage, we found no significant differences in 5y-OS (HR 1.12, 95% CI 0.66-1.91), 5y-RFS (HR 1.12, 95% CI 0.67-1.83), or 5y-CSS rates (HR 1.00, 95% CI 0.57-1.75). For short-term outcomes, significant intergroup differences in operation time (p=0.02), blood loss (p<0.001), postoperative length of stay (p<0.001), and incidence of atelectasis (p=0.004) were observed. The results of the sensitivity analysis were similar to the main results. CONCLUSIONS: In thoracoscopic procedures, CO2 insufflation significantly improved short-term outcomes, and it appears that the recurrence risk of esophageal cancer may not impact the long-term prognosis. While the influence of CO2 insufflation in thoracoscopic esophageal surgery remains unclear, our study suggests that the long-term prognosis is not compromised in other thoracic surgeries.

Maximum Efficacy of Immune Checkpoint Inhibitors Occurs in Esophageal Cancer Patients With a Low Neutrophil-to-Lymphocyte Ratio and Good Performance Status Prior to Treatment.

BACKGROUND/AIM: Immune checkpoint inhibitors (ICIs) play an important role in the treatment of esophageal cancer (EC). However, few patients achieve long-term survival, and some patients develop serious immune-related adverse events (irAEs). Reliable predictive biomarkers of efficacy and safety need to be established in order to improve efficacy. We retrospectively analyzed the outcomes of nivolumab monotherapy on EC at Showa University, Department of Medicine, to identify biomarkers and characteristics of patients who benefit from ICI monotherapy. PATIENTS AND METHODS: Eighty-six patients with EC who received nivolumab monotherapy were included in the present study. Patient characteristics, efficacy, and safety were analyzed. A multivariable analysis evaluated the correlation among overall survival (OS), progression-free survival (PFS), best overall response (BOR), irAEs, and the following variables: sex, age, performance status (PS), neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP) level, albumin level, and body-mass index before treatment. RESULTS: Median PFS was 3.1 months, and median OS was 9.0 months. In multivariable analysis, pretreatment PS, NLR, and sex were significantly correlated with OS and PFS. NLR <3.3 predicted longer survival (median OS 17.5 vs. 6.4 months for NLR ≥3.3; p<0.001). Median OS was 10.6 months for PS 0-1 and 1.3 months for PS 2-3 (p<0.001). NLR remained significantly predictive in the PS 0-1 group. The development of irAEs was significantly associated with increased OS and PFS. CONCLUSION: Patients with low NLR and good PS before treatment may maximize the benefits of ICIs. A low NLR may be an indicator of higher immunocompetence for anti-tumor immunity, suggesting that NLR may be a convenient predictive biomarker in daily practice.

Recent advances in microscale separation techniques for glycome analysis.

The glycomic analysis holds significant appeal due to the diverse roles that glycans and glycoconjugates play, acting as modulators and mediators in cellular interactions, cell/organism structure, drugs, energy sources, glyconanomaterials, and more. The glycomic analysis relies on liquid-phase separation technologies for molecular purification, separation, and identification. As a miniaturized form of liquid-phase separation technology, microscale separation technologies offer various advantages such as environmental friendliness, high resolution, sensitivity, fast speed, and integration capabilities. For glycan analysis, microscale separation technologies are continuously evolving to address the increasing challenges in their unique manners. This review discusses the fundamentals and applications of microscale separation technologies for glycomic analysis. It covers liquid-phase separation technologies operating at scales generally less than 100 µm, including capillary electrophoresis, nanoflow liquid chromatography, and microchip electrophoresis. We will provide a brief overview of glycomic analysis and describe new strategies in microscale separation and their applications in glycan analysis from 2014 to 2023.

Does Prehabilitation Reduce Postoperative Length of Hospital Stay after Esophageal Cancer Surgery?

Objectives: At our hospital, prehabilitation has been provided to patients undergoing esophageal cancer surgery since October 2019. This study explored the effects of prehabilitation based on the accumulated database of these patients. Methods: This retrospective cohort study included 621 patients who underwent thoracoscopic subtotal esophagectomy. Multiple linear regression analysis was performed using postoperative hospital stay as the objective variable and age, sex, body mass index (BMI), preoperative ventilatory impairment, left ventricular ejection fraction, preoperative hemoglobin A1c, clinical stage, histological type, operative time, surgical blood loss, postoperative complications, and prehabilitation as explanatory variables. We also performed a multivariate analysis in the subgroup of patients who developed postoperative complications and adjusted for possible confounding factors. Postoperative complications and postoperative hospital stay were compared between patients without (n=416) and with (n=205) prehabilitation. Results: Postoperative complications, age, blood loss, BMI, and ventilatory impairment influenced the overall length of hospital stay. When the analysis was restricted to patients with complications, prehabilitation was added to that list of factors as a substitute for BMI. The rate of postoperative complications was not affected by prehabilitation (P=0.1675). The number of hospital days did not change with or without prehabilitation in the overall population, but when restricted to patients with complications, the number of hospital days was significantly decreased in the prehabilitation group (P=0.0328). Conclusions: Prehabilitation as a perioperative approach has the potential to reduce the postoperative length of hospital stay in patients undergoing esophageal cancer surgery, and active intervention is recommended.

Butyricimonas is a key gut microbiome component for predicting postoperative recurrence of esophageal cancer.

BACKGROUND: Recently, intestinal bacteria have attracted attention as factors affecting the prognosis of patients with cancer. However, the intestinal microbiome is composed of several hundred types of bacteria, necessitating the development of an analytical method that can allow the use of this information as a highly accurate biomarker. In this study, we investigated whether the preoperative intestinal bacterial profile in patients with esophageal cancer who underwent surgery after preoperative chemotherapy could be used as a biomarker of postoperative recurrence of esophageal cancer. METHODS: We determined the gut microbiome of the patients using 16S rRNA metagenome sequencing, followed by statistical analysis. Simultaneously, we performed a machine learning analysis using a random forest model with hyperparameter tuning and compared the data obtained. RESULTS: Statistical and machine learning analyses revealed two common bacterial genera, Butyricimonas and Actinomyces, which were abundant in cases with recurrent esophageal cancer. Butyricimonas primarily produces butyrate, whereas Actinomyces are oral bacteria whose function in the gut is unknown. CONCLUSION: Our results indicate that Butyricimonas spp. may be a biomarker of postoperative recurrence of esophageal cancer. Although the extent of the involvement of these bacteria in immune regulation remains unknown, future research should investigate their presence in other pathological conditions. Such research could potentially lead to a better understanding of the immunological impact of these bacteria on patients with cancer and their application as biomarkers.

Diagnosis and Treatment of Metastatic Colon Cancer in Pregnancy First Presenting as Multiple Liver Masses: A Case Report.

Colorectal cancer (CRC) is the second most common cancer in women in Japan. However, it is uncommon during pregnancy. CRC diagnosis during pregnancy is often complicated and delayed due to the overlapping of symptoms, such as abdominal pain and nausea, with those of pregnancy and the limitations placed on potential diagnostic imaging and testing because of concerns for the fetus. A 39-year-old woman was referred from a local hospital at 32 weeks gestation after persistent right abdominal pain, which prompted an ultrasound that showed multiple liver lesions suggestive of malignancy. A combination of non-contrast computed tomography, non-contrast magnetic resonance imaging, contrast-enhanced ultrasound, and colonoscopy was utilized to make a definitive diagnosis; ultimately, colonoscopy confirmed the diagnosis of colon cancer with liver metastasis. A discussion within a multidisciplinary team led to the decision to deliver at 34 weeks by cesarean section and a left hemicolectomy was performed after delivery. The neonate was admitted to the neonatal intensive care unit due to prematurity but had no other complications. Chemotherapy was promptly initiated, and treatment was continued on an outpatient basis. Diagnostic algorithms for CRC during pregnancy are not yet well-established; however, the prognosis of CRC during pregnancy is poor, and clinicians should not hesitate to perform the necessary testing and consult experts in fields such as neonatology, medical oncology, internal medicine, and gastrointestinal surgery. Early diagnosis and intervention are essential for optimizing outcomes for both the mother and the fetus.

Rapid and Highly Efficient Purification of Extracellular Vesicles Enabled by a TiO2 Hybridized Spongy-like Polymer.

We developed a novel purification medium of extracellular vesicles (EVs) by constructing a spongy-like monolithic polymer kneaded with TiO2 microparticles (TiO2-hybridized spongy monolith, TiO2-SPM). TiO2-SPM was applied in a solid-phase extraction format and enabled simple, rapid, and highly efficient purification of EVs. This is due to the high permeability caused by the continuous large flow-through pores of the monolithic skeleton (median pore size; 5.21 µm) and the specific interaction of embedded TiO2 with phospholipids of the lipid bilayers. Our method also excels in efficiency and comprehensiveness, collecting small EVs (SEVs) from the same volume of a cell culture medium 130.7 times more than typical ultracentrifugation and 4.3 times more than affinity purification targeting surface phosphatidylserine by magnetic beads. The purification method was completed within 1 h with simple operations and was directly applied to serum SEVs. Finally, we demonstrated flexibility toward the shape and size of our method by depleting EVs from fetal bovine serum (FBS), which is a necessary process to prevent contamination of culture cell-derived EVs with exogenous FBS-derived EVs. Our method will eliminate the tedious and difficult purification processes of EVs, providing a universal purification platform for EV-based drug discovery and pathological diagnosis.

Efficient Selective Adsorption of SARS-CoV-2 via the Recognition of Spike Proteins Using an Affinity Spongy Monolith.

Since the outbreak of COVID-19, SARS-CoV-2, the infection has been spreading to date. The rate of false-negative result on a polymerase chain reaction (PCR) test considered the gold standard is roughly 20%. Therefore, its accuracy poses a question as well as needs improvement in the test. This study reports fabrication of a substrate of an anti-spike protein (AS)-immobilized porous material having selective adsorption toward a spike protein protruding from the surface of SARS-CoV-2. We have employed an organic polymer substrate called spongy monolith (SPM). The SPM has through-pores of about 10 µm and is adequate for flowing liquid containing virus particles. It also involves an epoxy group on the surface, enabling arbitrary proteins such as antibodies to immobilize. When antibodies of the spike protein toward receptor binding domain were immobilized, selective adsorption of the spike protein was observed. At the same time, when mixed analytes of spike proteins, lysozymes and amylases, were flowed into an AS-SPM, selective adsorption toward the spike proteins was observed. Then, SARS-CoV-2 was flowed into the BSA-SPM or AS-SPM, amounts of SARS-CoV-2 adsorption toward the AS-SPM were much larger compared to the ones toward the BSA-SPM. Furthermore, rotavirus was not adsorbed to the AS-SPM at all. These results show that the AS-SPM recognizes selectively the spike proteins of SARS-CoV-2 and may be possible applications for the purification and concentration of SARS-CoV-2.

Thoracoscopic esophageal drainage for tracheal compression due to mucocele after esophagogastric bypass: a case report.

BACKGROUND: Esophagogastric bypass is performed for esophageal strictures. Mucus retention, known as mucocele, sometimes occurs at the stricture oral side of the remnant esophagus. It is often asymptomatic and is expected to be naturally decompressed, but it may cause respiratory failure depending on the case. Herein, we report a case in which we successfully performed thoracoscopic esophageal drainage as emergency airway management due to tracheal compression by a mucocele after esophagogastric bypass for unresectable esophageal cancer with esophagobronchial fistula. CASE PRESENTATION: A 56-year-old man underwent esophageal bypass surgery for an unresectable esophageal carcinoma with an esophagobronchial fistula following chemotherapy and radiation therapy. Nine months after bypass surgery, he experienced severe dyspnea due to tracheal compression caused by mucus retention on the oral side of the esophageal tumor. We planned thoracoscopic surgery for mucus retention drainage through the right thoracic cavity to secure the airway as an emergency procedure under general anesthesia. Intubation can be performed safely by guiding bronchoscopy in the semi-supine position. Upper esophageal dilation was observed on the cranial side of the azygos arch. We dissected the mediastinal pleura of the upper thoracic esophagus and exposed its wall. A 12-Fr silicone drain was placed in the esophagus through the right chest wall and 120 ml of white fluid was aspirated. He was discharged 9 days after surgery without complications and resumed treatment with an immune checkpoint inhibitor 23 days after surgery. Thereafter, he continued chemotherapy for esophageal cancer, but died of tumor progression and lung metastasis 35 months after bypass surgery and 25 months after thoracoscopic surgery. CONCLUSIONS: Thoracoscopic esophageal drainage could be performed safely as emergency airway management, shorten the period of discontinuance, and allow cancer treatment to be resumed promptly. We believe that this thoracoscopic procedure is an effective and less invasive method if the percutaneous approach is difficult.

Rational Supramolecular Strategy via Halogen Bonding for Effective Halogen Recognition in Molecular Imprinting.

Halogen bonding is a highly directional interaction and a potential tool in functional material design through self-assembly. Herein, we describe two fundamental supramolecular strategies to synthesize molecularly imprinted polymers (MIPs) with halogen bonding-based molecular recognition sites. In the first method, the size of the σ-hole was increased by aromatic fluorine substitution of the template molecule, enhancing the halogen bonding in the supramolecule. The second method involved sandwiching hydrogen atoms of a template molecule between iodo substituents, which suppressed competing hydrogen bonding and enabled multiple recognition patterns, improving the selectivity. The interaction mode between the functional monomer and the templates was elucidated by 1H NMR, 13C NMR, X-ray absorption spectroscopy, and computational simulation. Finally, we succeeded in the effective chromatographic separation of diiodobenzene isomers on the uniformly sized MIPs prepared by multi-step swelling and polymerization. The MIPs selectively recognized halogenated thyroid hormones via halogen bonding and could be applied to screening endocrine disruptors.

Rational Strategy for Space-Confined Atomic Layer Deposition.

Atomic layer deposition (ALD) offers excellent controllability of spatial uniformity, film thickness at the Angstrom level, and film composition even for high-aspect-ratio nanostructured surfaces, which are rarely attainable by other conventional deposition methodologies. Although ALD has been successfully applied to various substrates under open-top circumstances, the applicability of ALD to confined spaces has been limited because of the inherent difficulty of supplying precursors into confined spaces. Here, we propose a rational methodology to apply ALD growths to confined spaces (meter-long microtubes with an aspect ratio of up to 10 000). The ALD system, which can generate differential pressures to confined spaces, was newly developed. By using this ALD system, it is possible to deposit TiOx layers onto the inner surface of capillary tubes with a length of 1000 mm and an inner diameter of 100 µm with spatial deposition uniformity. Furthermore, we show the superior thermal and chemical robustness of TiOx-coated capillary microtubes for molecular separations when compared to conventional molecule-coated capillary microtubes. Thus, the present rational strategy of space-confined ALD offers a useful approach to design the chemical and physical properties of the inner surfaces of various confined spaces.

Clinical Treatment of Perioperative Disseminated Intravascular Coagulation in Patients Who Underwent Gastrointestinal and Hepato-Biliary-Pancreatic Surgery.

BACKGROUND: It is unclear how effective recombinant thrombomodulin (rTM) treatment is in disseminated intravascular coagulation (DIC) during the perioperative period of gastrointestinal and hepato-biliary-pancreatic surgery. The current study aimed to evaluate the therapeutic outcomes of rTM for perioperative DIC. METHODS: We enrolled 100 consecutive patients diagnosed with perioperative DIC after gastrointestinal surgery, and hepato-biliary-pancreatic including emergency procedures, between January 2012 and May 2021. Patients received routine rTM treatment immediately after DIC diagnosis. Then, the DIC, Sequential Organ Failure Assessment (SOFA), and Acute Physiology and Chronic Health Evaluation (APACHE) II scores were calculated and used for evaluation. The outcomes of rTM treatment and the predictors of survival were evaluated. RESULTS: The causative diseases of DIC were as follows: perforated peritonitis, n = 38; intestinal ischemia, n = 23; intra-abdominal abscess, n = 13; anastomotic leakage, n = 7; pneumonia, n = 7; cholangitis, n = 4; and others, n = 6. The 30-day mortality rate was 18.0%. There were significant differences in the platelet count (13.78 vs 10.41, P = .032) and the SOFA score (5.22 vs 9.89, P<.0001) at the start of DIC treatment between the survivor and non-survivor groups (day 0). The survivor group had a significantly lower DIC score (3.13 vs 4.93, P = .0006) and SOFA score (4.94 vs 12.14, P < .0001) and a higher platelet count (13.50 vs 4.34, P < .0001) than the non-survivor group on day 3. CONCLUSIONS: Comprehensive and systemic treatment is fundamentally essential for DIC, in which rTM may play an important role in the treatment of perioperative DIC.

Comparison of Endotoxin Activity Assay and Various Biomarkers for Severity Assessment in Colorectal Perforation Patients.

Colorectal perforation is a serious disease with high mortality requiring emergency surgery. This study aimed to evaluate the role of the endotoxin activity assay (EAA) to assess the severity in patients admitted to the intensive care unit after emergency surgeries for colorectal perforations. Patients were divided into high (EAA ≥.4) and low (EAA <.4) groups based on the EAA levels, and the correlation between the EAA values and clinical variables related to the severity was evaluated. The SOFA scores were significantly higher in the high group than those in the low group. The high EAA value persisted even after 48 hours and extended the ICU length of stay. These results suggest that EAA may be a potential biomarker to assess severity and useful as one of the instrumental in predicting the outcomes for colorectal perforation patients.

Classification of Extracellular Vesicles Based on Surface Glycan Structures by Spongy-like Separation Media.

Extracellular vesicles (EVs) are lipid bilayer vesicles that enclose various biomolecules. EVs hold promise as sensitive biomarkers to detect and monitor various diseases. However, they have heterogeneous molecular compositions. The compositions of EVs from identical donor cells obtained using the same purification methods may differ, which is a significant obstacle for elucidating objective biological functions. Herein, the potential of a novel lectin-based affinity chromatography (LAC) method to classify EVs based on their glycan structures is demonstrated. The proposed method utilizes a spongy-like monolithic polymer (spongy monolith, SPM), which consists of poly(ethylene-co-glycidyl methacrylate) with continuous micropores and allows an efficient in situ protein reaction with epoxy groups. Two distinct lectins with different specificities, Sambucus sieboldiana agglutinin and concanavalin A, are effectively immobilized on SPM without impacting the binding activity. Moreover, high recovery rates of liposomal nanoparticles as a model of EVs are achieved due to the large flow-through pores (>10 µm) of SPM compared to a typical agarose gel. Finally, lectin-immobilized SPMs are employed to classify EVs based on the surface glycan structures and demonstrate different subpopulations by proteome profiling. This is the first approach to clarify the variation of protein contents in EVs by the difference of surface glycans via lectin immobilized media.

Predictive Factors of Febrile Neutropenia After Primary Prophylactic Pegfilgrastim With DCF Chemotherapy for Esophageal Cancer.

BACKGROUND/AIM: We investigated the predictive factors of febrile neutropenia (FN) after the administration of pegfilgrastim as primary prophylaxis in patients with esophageal cancer who received neoadjuvant chemotherapy with docetaxel, cisplatin, and 5-fluorouracil (DCF) to support the appropriate management of FN. We evaluated changes in neutrophil counts and relative dose intensity (RDI) after the incidence of FN. PATIENTS AND METHODS: This retrospective study involved 122 patients with esophageal cancer who were treated with DCF and pegfilgrastim at Showa University Hospital, Japan, between April 2016 and August 2021. The primary outcome was FN incidence after cycle 1 of DCF chemotherapy. The significant independent factors associated with FN incidence were selected using the multivariate analysis. Changes in neutrophil counts and RDI were compared between the FN and non-FN groups. RESULTS: One-hundred patients were included in the analysis. The incidence of FN in cycle 1 was 21%. In the multivariate analysis, geriatric nutritional risk index (GNRI) <92 [odds ratio (OR)=13.162, p<0.001] and combination of platelet and neutrophil-to-lymphocyte ratio (COP-NLR) score of 0 (OR=4.619, p=0.012) were independent predictors of FN. The neutrophil count on day 7-10 and RDI in the FN group were lower than those in the non-FN group (all p<0.05). CONCLUSION: GNRI <92 and COP-NLR score of 0 are important indicators to predict patients at high risk of DCF chemotherapy-induced FN. Furthermore, FN incidence after pegfilgrastim administration had a strong effect on delayed neutrophil recovery and reduced RDI.

Selective Separation of Thyroid-Hormone-Receptor-Binding Substances Using Molecularly Imprinted Polymers.

To date, an identification protocol for endocrine disruptors that bind to the thyroid hormone receptor (TR) has not been established. A method for screening and identifying TR-binding substances is highly required due to the existence of unknown TR-binding substances from the environment. Here, we conceived a chromatographic method using a molecularly imprinted polymer (MIP) to create a novel screening protocol for the endocrine disruptors. A receptor-imitating MIP was prepared using N-acetylthyroxine (AcetylT4) and 4-vinylpyridine as a pseudo-template and a functional monomer, respectively, based on the existing molecular recognition mechanism of the TR. The receptor-imitating MIP provided molecular recognition ability for all the TR-binding substances that were employed in this study. The prepared MIPs were packed into a high-performance liquid chromatography column for the simultaneous analysis of TR-binding and non-binding substances. The former was strongly retained, while the latter was not. The presence or absence of TR-binding/non-binding activity resulted in successful dichotomous separation. Additionally, the surface imprinting technique was applied to improve the separation performance of the MIP packing material. MIP-coated uniformly sized silica-based particles of 5 µm were successfully prepared, and the MIP-coated silica column enabled more efficient dichotomous separation of TR-binding and non-binding substances.

Moderate molecular recognitions on ZnO m-plane and their selective capture/release of bio-related phosphoric acids.

Herein, we explore the hidden molecular recognition abilities of ZnO nanowires uniformly grown on the inner surface of an open tubular fused silica capillary via liquid chromatography. Chromatographic evaluation revealed that ZnO nanowires showed a stronger intermolecular interaction with phenylphosphoric acid than any other monosubstituted benzene. Furthermore, ZnO nanowires specifically recognized the phosphate groups present in nucleotides even in the aqueous mobile phase, and the intermolecular interaction increased with the number of phosphate groups. This discrimination of phosphate groups in nucleotides was unique to the rich (101̄0) m-plane of ZnO nanowires with a moderate hydrophilicity and negative charge. The discrimination could be evidenced by the changes in the infrared bands of the phosphate groups on nucleotides on ZnO nanowires. Finally, as an application of the molecular recognition, nucleotides were separated by the number of phosphate groups, utilizing optimized gradient elution on ZnO nanowire column. Thus, the present results elucidate the unique and versatile molecular selectivity of well-known ZnO nanostructures for the capture and separation of biomolecules.

Specific recognition of a target protein, cytochrome c, using molecularly imprinted hydrogels.

Protein imprinted hydrogel, which is one form of protein imprinted molecularly imprinted polymer (MIP), is an important material for enzyme-linked immunosorbent assay, drug delivery materials, sensors, separation materials, etc. To obtain a high protein recognition performance, it is essential to optimize the involved compositions. This work studies a copoly(poly(ethylene glycol) diacrylate/poly(ethylene glycol) acrylate), in short copoly(PEGDA/PEGA), based MIP hydrogel targeting cytochrome c recognition. The presented MIP hydrogel employs water-soluble PEGDA as the crosslinker, PEGA as the side chain, and sodium allylsulfonate as the functional monomer. The fabricated MIP hydrogels and non-imprinted polymer (NIP) hydrogels were treated as adsorbents for protein adsorption. Efforts were made targeting an optimized recognition performance. Factors including the template to functional monomer ratio, crosslinker length, crosslinker ratio of PEGDA/PEGA, ionic strength in the adsorption test, and presence of acidic modifier in the adsorption test were investigated. The results showed that a higher template to functional monomer ratio, a shorter crosslinker, and additional NaCl (20 mM) in the adsorption solvent provided a higher imprinting factor. A lower crosslinker ratio of no less than 6/4 offered a faster template removal; at the same time, the imprinting factor remained at a quite high level. Highly specific recognition of cytochrome c was realized with the presence of an optimized amount of HCl (10 mM) as an acidic modifier.