Classification of the Urgency of the Procedure and Outcome of Acute Type A Aortic Dissection.

Surgery for type A aortic dissection (TAAD) is associated with a high risk of early mortality. The prognostic impact of a new classification of the urgency of the procedure was evaluated in this multicenter cohort study. Data on consecutive patients who underwent surgery for acute TAAD were retrospectively collected in the multicenter, retrospective European Registry of TAAD (ERTAAD). The rates of in-hospital mortality of 3,902 consecutive patients increased along with the ERTAAD procedure urgency grades: urgent procedure 10.0%, emergency procedure grade 1 13.3%, emergency procedure grade 2 22.1%, salvage procedure grade 1 45.6%, and salvage procedure grade 2 57.1% (p <0.0001). Preoperative arterial lactate correlated with the urgency grades. Inclusion of the ERTAAD procedure urgency classification significantly improved the area under the receiver operating characteristics curves of the regression model and the integrated discrimination indexes and the net reclassification indexes. The risk of postoperative stroke/global brain ischemia, mesenteric ischemia, lower limb ischemia, dialysis, and acute heart failure increased along with the urgency grades. In conclusion, the urgency of surgical repair of acute TAAD, which seems to have a significant impact on the risk of in-hospital mortality, may be useful to improve the stratification of the operative risk of these critically ill patients. This study showed that salvage surgery for TAAD is justified because half of the patients may survive to discharge.

Identification of non-conventional small molecule degraders and stabilizers of squalene synthase.

Squalene synthase (SQS) is an essential enzyme in the mevalonate pathway, which controls cholesterol biosynthesis and homeostasis. Although catalytic inhibitors of SQS have been developed, none have been approved for therapeutic use so far. Herein we sought to develop SQS degraders using targeted protein degradation (TPD) to lower overall cellular cholesterol content. We found that KY02111, a small molecule ligand of SQS, selectively causes SQS to degrade in a proteasome-dependent manner. Unexpectedly, compounds based on the same scaffold linked to E3 ligase recruiting ligands led to SQS stabilization. Proteomic analysis found KY02111 to reduce only the levels of SQS, while lipidomic analysis determined that KY02111-induced degradation lowered cellular cholesteryl ester content. Stabilizers shielded SQS from its natural turnover without recruiting their matching E3 ligase or affecting enzymatic target activity. Our work shows that degradation of SQS is possible despite a challenging biological setting and provides the first chemical tools to degrade and stabilize SQS.

Preoperative arterial lactate and outcome after surgery for type A aortic dissection: The ERTAAD multicenter study.

Background: Acute type A aortic dissection (TAAD) is associated with significant mortality and morbidity. In this study we evaluated the prognostic significance of preoperative arterial lactate concentration on the outcome after surgery for TAAD. Methods: The ERTAAD registry included consecutive patients who underwent surgery for acute type A aortic dissection (TAAD) at 18 European centers of cardiac surgery. Results: Data on arterial lactate concentration immediately before surgery were available in 2798 (71.7 %) patients. Preoperative concentration of arterial lactate was an independent predictor of in-hospital mortality (mean, 3.5 ± 3.2 vs 2.1 ± 1.8 mmol/L, adjusted OR 1.181, 95%CI 1.129-1.235). The best cutoff value preoperative arterial lactate concentration was 1.8 mmol/L (in-hospital mortality, 12.0 %, vs. 26.6 %, p < 0.0001). The rates of in-hospital mortality increased along increasing quintiles of arterial lactate and it was 12.1 % in the lowest quintile and 33.6 % in the highest quintile (p < 0.0001). The difference between multivariable models with and without preoperative arterial lactate was statistically significant (p = 0.0002). The NRI was 0.296 (95%CI 0.200-0.391) (p < 0.0001) with -17 % of events correctly reclassified (p = 0.0002) and 46 % of non-events correctly reclassified (p < 0.0001). The IDI was 0.025 (95%CI 0.016-0.034) (p < 0.0001). Six studies from a systematic review plus the present one provided data for a pooled analysis which showed that the mean difference of preoperative arterial lactate between 30-day/in-hospital deaths and survivors was 1.85 mmol/L (95%CI 1.22-2.47, p < 0.0001, I2 64 %). Conclusions: Hyperlactatemia significantly increased the risk of mortality after surgery for acute TAAD and should be considered in the clinical assessment of these critically ill patients.

Direct Aortic Versus Supra-Aortic Arterial Cannulation During Surgery for Acute Type A Aortic Dissection.

AIMS: In this study we evaluated the impact of direct aortic cannulation versus innominate/subclavian/axillary artery cannulation on the outcome after surgery for type A aortic dissection. METHODS: The outcomes of patients included in a multicenter European registry (ERTAAD) who underwent surgery for acute type A aortic dissection with direct aortic cannulation versus those with innominate/subclavian/axillary artery cannulation, i.e. supra-aortic arterial cannulation, were compared using propensity score matched analysis. RESULTS: Out of 3902 consecutive patients included in the registry, 2478 (63.5%) patients were eligible for this analysis. Direct aortic cannulation was performed in 627 (25.3%) patients, while supra-aortic arterial cannulation in 1851 (74.7%) patients. Propensity score matching yielded 614 pairs of patients. Among them, patients who underwent surgery for TAAD with direct aortic cannulation had significantly decreased in-hospital mortality (12.7% vs. 18.1%, p = 0.009) compared to those who had supra-aortic arterial cannulation. Furthermore, direct aortic cannulation was associated with decreased postoperative rates of paraparesis/paraplegia (2.0 vs. 6.0%, p < 0.0001), mesenteric ischemia (1.8 vs. 5.1%, p = 0.002), sepsis (7.0 vs. 14.2%, p < 0.0001), heart failure (11.2 vs. 15.2%, p = 0.043), and major lower limb amputation (0 vs. 1.0%, p = 0.031). Direct aortic cannulation showed a trend toward decreased risk of postoperative dialysis (10.1 vs. 13.7%, p = 0.051). CONCLUSIONS: This multicenter cohort study showed that direct aortic cannulation compared to supra-aortic arterial cannulation is associated with a significant reduction of the risk of in-hospital mortality after surgery for acute type A aortic dissection. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04831073.

Current Outcome after Surgery for Type A Aortic Dissection.

OBJECTIVE: The aim of this study was to evaluate the outcomes of different surgical strategies for acute Stanford type A aortic dissection (TAAD). SUMMARY BACKGROUND DATA: The optimal extent of aortic resection during surgery for acute TAAD is controversial. METHODS: This is a multicenter, retrospective cohort study of patients who underwent surgery for acute TAAD at 18 European hospitals. RESULTS: Out of 3902 consecutive patients, 689 (17.7%) died during the index hospitalization. Among 2855 patients who survived 3 months after surgery, 10-year observed survival was 65.3%, while country-adjusted, age-adjusted, and sex-adjusted expected survival was 81.3%, yielding a relative survival of 80.4%. Among 558 propensity score-matched pairs, total aortic arch replacement increased the risk of in-hospital (21.0% vs. 14.9%, P =0.008) and 10-year mortality (47.1% vs. 40.1%, P =0.001), without decreasing the incidence of distal aortic reoperation (10-year: 8.9% vs. 7.4%, P =0.690) compared with ascending aortic replacement. Among 933 propensity score-matched pairs, in-hospital mortality (18.5% vs. 18.0%, P =0.765), late mortality (at 10-year: 44.6% vs. 41.9%, P =0.824), and cumulative incidence of proximal aortic reoperation (at 10-year: 4.4% vs. 5.9%, P =0.190) after aortic root replacement was comparable to supracoronary aortic replacement. CONCLUSIONS: Replacement of the aortic root and aortic arch did not decrease the risk of aortic reoperation in patients with TAAD and should be performed only in the presence of local aortic injury or aneurysm. The relative survival of TAAD patients is poor and suggests that the causes underlying aortic dissection may also impact late mortality despite surgical repair of the dissected aorta.

Perimount MAGNA Ease vs. INSPIRIS Resilia Valve: A PS-Matched Analysis of the Hemodynamic Performances in Patients below 70 Years of Age.

BACKGROUND: During the past decade, the Perimount Magna Ease (PME) bioprosthesis has been implanted worldwide for aortic valve replacement (AVR). Recently, the INSPIRIS Resilia (IR) valve has been introduced as the newest generation of pericardial bioprostheses. However, few data have been reported about patients ≤70 years, and no comparisons in terms of hemodynamic performance between these two bioprostheses have been ever reported. METHODS: Patients aged <70 years undergoing AVR were considered for comparison between PME (n = 238) and IR (n = 192). Propensity score (PS) matching was performed by logistic regression with adjustment for eight key baseline variables. The two prostheses were compared in terms of hemodynamic performances up to 3 years postoperatively. Sub-analysis according to prosthetic size-category was accomplished. RESULTS: A total of 122 pairs with similar baseline characteristics were obtained from the PS-matching. The two prostheses showed comparable hemodynamic performances at one year (Gmean: 11.3 ± 3.5 mmHg vs. 11.9 ± 5.4 mmHg; p = 0.8) and at 3 years postoperatively (Gmean: 12.2 ± 7.9 mmHg vs. 12.8 ± 5.2 mmHg for; p = 0.3). The sub-analysis of size-category confirmed no statistical differences concerning the hemodynamic performances for each annulus size. CONCLUSIONS: This first PS-matched analysis demonstrated that the newly developed IR valve achieves the same safety and efficacy of the PME valve during mid-term follow-up in patients aged <70 years.

Interinstitutional analysis of the outcome after surgery for type A aortic dissection.

PURPOSE: To evaluate the impact of individual institutions on the outcome after surgery for Stanford type A aortic dissection (TAAD). METHODS: This is an observational, multicenter, retrospective cohort study including 3902 patients who underwent surgery for TAAD at 18 university and non-university hospitals. RESULTS: Logistic regression showed that four hospitals had increased risk of in-hospital mortality, while two hospitals were associated with decreased risk of in-hospital mortality. Risk-adjusted in-hospital mortality rates were lower in four hospitals and higher in other four hospitals compared to the overall in-hospital mortality rate (17.7%). Participating hospitals were classified as overperforming or underperforming if their risk-adjusted in-hospital mortality rate was lower or higher than the in-hospital mortality rate of the overall series, respectively. Propensity score matching yielded 1729 pairs of patients operated at over- or underperforming hospitals. Overperforming hospitals had a significantly lower in-hospital mortality (12.8% vs. 22.2%, p < 0.0001) along with decreased rate of stroke and/or global brain ischemia (16.5% vs. 19.9%, p = 0.009) compared to underperforming hospitals. Aggregate data meta-regression of the results of participating hospitals showed that hospital volume was inversely associated with in-hospital mortality (p = 0.043). Hospitals with an annual volume of less than 15 cases had an increased risk of in-hospital mortality (adjusted OR, 1.345, 95% CI 1.126-1.607). CONCLUSION: The present findings indicate that there are significant differences between hospitals in terms of early outcome after surgery for TAAD. Low hospital volume may be a determinant of poor outcome of TAAD. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04831073.

Outcome after Surgery for Iatrogenic Acute Type A Aortic Dissection.

(1) Background: Acute Stanford type A aortic dissection (TAAD) may complicate the outcome of cardiovascular procedures. Data on the outcome after surgery for iatrogenic acute TAAD is scarce. (2) Methods: The European Registry of Type A Aortic Dissection (ERTAAD) is a multicenter, retrospective study including patients who underwent surgery for acute TAAD at 18 hospitals from eight European countries. The primary outcomes were in-hospital mortality and 5-year mortality. Twenty-seven secondary outcomes were evaluated. (3) Results: Out of 3902 consecutive patients who underwent surgery for acute TAAD, 103 (2.6%) had iatrogenic TAAD. Cardiac surgery (37.8%) and percutaneous coronary intervention (36.9%) were the most frequent causes leading to iatrogenic TAAD, followed by diagnostic coronary angiography (13.6%), transcatheter aortic valve replacement (10.7%) and peripheral endovascular procedure (1.0%). In hospital mortality was 20.5% after cardiac surgery, 31.6% after percutaneous coronary intervention, 42.9% after diagnostic coronary angiography, 45.5% after transcatheter aortic valve replacement and nihil after peripheral endovascular procedure (p = 0.092), with similar 5-year mortality between different subgroups of iatrogenic TAAD (p = 0.710). Among 102 propensity score matched pairs, in-hospital mortality was significantly higher among patients with iatrogenic TAAD (30.4% vs. 15.7%, p = 0.013) compared to those with spontaneous TAAD. This finding was likely related to higher risk of postoperative heart failure (35.3% vs. 10.8%, p < 0.0001) among iatrogenic TAAD patients. Five-year mortality was comparable between patients with iatrogenic and spontaneous TAAD (46.2% vs. 39.4%, p = 0.163). (4) Conclusions: Iatrogenic origin of acute TAAD is quite uncommon but carries a significantly increased risk of in-hospital mortality compared to spontaneous TAAD.

Transapical Transcatheter Aortic Valve Replacement: A Real-World Early and Mid-Term Outcome of a Third-Level Centre.

BACKGROUND: Transapical transcatheter aortic valve replacement (TA-TAVR) is generally considered to be associated with higher morbidity compared with transfemoral-TAVR. However, TA-TAVR remains a feasible alternative for patients who are unsuitable for TF-TAVR. It has been shown that outcomes after TAVR are linked to the operator's expertise. Therefore, the purpose of this study is to report short- and mid-term outcomes after TA-TAVR performed by an expert Heart-Team of a third-level centre. METHODS: From 2015 to 2022, 154 consecutive patients underwent TA-TAVR. The outcomes were analysed according to the VARC-3 criteria. Kaplan-Meier curves were estimated for major clinical events at mid-term follow-up. RESULTS: The mean age of the population was 79.3 years and the STS risk-score of mortality was 4.2 ± 3.6%. Periprocedural mortality was 1.9%. Acute kidney injury and prolonged ventilation occurred in 1.9%. Incidence of stroke was 0.6%. Pacemaker implantation rate was 1.9%. Freedom from cardiovascular mortality was 75.7%, and 60.2% at 3 and 5 years. Freedom from stroke was 92.3% and 88.9% at 3 and 5 years, respectively; freedom from endocarditis was 94.4% and 90.8% at 3 and 5 years, respectively. CONCLUSION: TA-TAVR may be considered a safe and effective alternative approach in patients unsuitable for TF-TAVR, especially when performed by a proficient Heart-Team.

Thermal Proteome Profiling Reveals Distinct Target Selectivity for Differentially Oxidized Oxysterols.

Oxysterols are produced physiologically by many species; however, their distinct roles in regulating human physiology have not been studied systematically. The role of differing oxidation states and sites in mediating their biological functions is also unclear. As oxysterols have been associated with atherosclerosis, neurodegeneration, and cancer, a better understanding of their protein targets is desirable. To address this, we mapped the oxysterol interactome with three A- and B-ring oxidized sterols as well as 25-hydroxy cholesterol using thermal proteome profiling, validating selected targets with the cellular thermal shift assay and isothermal dose response fingerprinting. This revealed that the site of oxidation has a profound impact on target selectivity, with each oxysterol possessing an almost unique set of target proteins. Overall, targets clustered in pathways relating to vesicular transport and phosphoinositide metabolism, suggesting that while individual oxysterols bind to a unique set of proteins, the processes they modulate are highly interconnected.

Short-term outcome of adenosine-lidocaine-magnesium polarizing cardioplegia in humans.

OBJECTIVES: Hyperkalaemic depolarized myocardial arrest is the cornerstone of myocardial protection, although some potassium-related cytotoxicity has been demonstrated. Polarized arrest has gained interest because of a reported better myocardial protection in preclinical studies. The goal of this study was to analyse the quality of myocardial protection and hospital outcome after normokalaemic adenosine-lidocaine-magnesium (ALM) blood polarizing cardioplegia, compared to hyperkalaemic blood Buckberg depolarizing cardioplegia, in elective routine adult cardiac surgery. METHODS: One thousand consecutive elective adult cardiac patients [627 undergoing ALM-polarizing cardioplegia (ALM-POL) vs 373 Buckberg depolarized cardioplegia (BUCK-DEPOL)] who were operated on were analysed. Perioperative leakage of high-sensitivity troponin I (Hs-TnI), peripheral lactate, inotropic and vasoactive daily requirement [maximal vasoactive inotropic score (VISMAX)], hospital mortality and morbidity were collected and compared in the overall population and in the propensity score (PS) matched population (206 pairs). RESULTS: A significantly lower leakage of Hs-TnI during hospitalization was detected in patients receiving ALM-POL versus those receiving BUCK-DEPOL (group time P < 0.001 for overall population and PS matched pairs). The maximum value of postoperative Hs-TnI was also lower after ALM-POL (P < 0.001 in both cohorts), and spontaneous recovery of sinus rhythm at aortic declamping was higher (P < 0.001 in favour of ALM-POL). Maximal VISMAX during hospitalization was significantly higher after BUCK-DEPOL in both cohorts (P = 0.019 for overall population; P = 0.031 for PS matched population), with significantly higher VISMAX on the day of surgery in BUCK-DEPOL PS matched patients (P = 0.042). No other significant differences in hospital morbidity and mortality were found. CONCLUSIONS: Despite comparable short-term clinical outcomes, ALM-POL cardioplegia proved superior in terms of quality of myocardial protection compared to BUCK-DEPOL cardioplegia in elective routine adult cardiac surgery.

Cardioplegia between Evolution and Revolution: From Depolarized to Polarized Cardiac Arrest in Adult Cardiac Surgery.

Despite current advances in perioperative care, intraoperative myocardial protection during cardiac surgery has not kept the same pace. High potassium cardioplegic solutions were introduced in the 1950s, and in the early 1960s they were soon recognized as harmful. Since that time, surgeons have minimized many of the adverse effects by lowering the temperature of the heart, lowering K+ concentration, reducing contact K+ time, changing the vehicle from a crystalloid solution to whole-blood, adding many pharmacological protectants and modifying reperfusion conditions. Despite these attempts, high potassium remains a suboptimalway to arrest the heart. We briefly review the historical advances and failures of finding alternatives to high potassium, the drawbacks of a prolonged depolarized membrane, altered Ca2+ intracellular circuits and heterogeneity in atrial-ventricular K+ repolarization during reanimation. Many of these untoward effects may be alleviated by a polarized membrane, and we will discuss the basic science and clinical experience from a number of institutions trialling different alternatives, and our institution with a non-depolarizing adenosine, lidocaine and magnesium (ALM) cardioplegia. The future of polarized arrest is an exciting one and may play an important role in treating the next generation of patients who are older, and sicker with multiple comorbidities and require more complex operations with prolonged cross-clamping times.

Detection of Periodontal Pathogens in Oral Samples and Cardiac Specimens in Patients Undergoing Aortic Valve Replacement: A Pilot Study.

This observational study aimed to: (i) assess the presence of periodontal disease among patients requiring aortic valve replacement; (ii) investigate the presence of oral pathogens in aortic valve specimens and compare them with the microorganisms detected in the oral cavity. Twenty-six patients (15 men and 11 women) were scheduled to be visited the day before the cardiac surgery: periodontal conditions were accurately registered through clinical and radiographic examinations; dental plaque or salivary samples were collected. Valve specimens were collected during surgical aortic valve replacement and analyzed for pathogens detection through microbiological 16SrRna gene sequencing. Bacteria found in plaque samples and valve specimens were assessed according to oral and periodontal conditions. A qualitative comparison between oral and cardiac profiles of the microorganisms detected was performed. The overall number of patients examined for soft tissues conditions was 19, as 7 patients were edentulous. Twelve and three individuals, respectively, presented moderate and severe periodontitis. Nine valves were found to be positive for the presence of oral and periodontopathic bacterial DNA. The microbial species found in valve samples of patients with periodontitis suggest that the presence of these microorganisms in valvular tissue seems to be not coincidental.

European registry of type A aortic dissection (ERTAAD) - rationale, design and definition criteria.

BACKGROUND: Acute Stanford type A aortic dissection (TAAD) is a life-threatening condition. Surgery is usually performed as a salvage procedure and is associated with significant postoperative early mortality and morbidity. Understanding the patient's conditions and treatment strategies which are associated with these adverse events is essential for an appropriate management of acute TAAD. METHODS: Nineteen centers of cardiac surgery from seven European countries have collaborated to create a multicentre observational registry (ERTAAD), which will enroll consecutive patients who underwent surgery for acute TAAD from January 2005 to March 2021. Analysis of the impact of patient's comorbidities, conditions at referral, surgical strategies and perioperative treatment on the early and late adverse events will be performed. The investigators have developed a classification of the urgency of the procedure based on the severity of preoperative hemodynamic conditions and malperfusion secondary to acute TAAD. The primary clinical outcomes will be in-hospital mortality, late mortality and reoperations on the aorta. Secondary outcomes will be stroke, acute kidney injury, surgical site infection, reoperation for bleeding, blood transfusion and length of stay in the intensive care unit. DISCUSSION: The analysis of this multicentre registry will allow conclusive results on the prognostic importance of critical preoperative conditions and the value of different treatment strategies to reduce the risk of early adverse events after surgery for acute TAAD. This registry is expected to provide insights into the long-term durability of different strategies of surgical repair for TAAD. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04831073 .

Value of Perioperative Chest X-ray for the Prediction of Sternal Wound Complications after Cardiac Surgery in High-Risk Patients: A "Work in Progress" Analysis.

BACKGROUND: Sternal wound complications are serious events that occur after cardiac surgery. Few studies have investigated the predictive value of chest X-ray radiological measurements for sternal complications. METHODS: Several perioperative radiological measurements at chest X-ray and clinical characteristics were computed in 849 patients deemed at high risk for sternal dehiscence (SD) or More than Grade 1 Surgical Site Infection (MG1-SSI). Multivariable analysis identified independent predictors, whilst receiver operating characteristics (ROC) curve analyses highlighted cut-off values of radiological measurements for the prediction of both complications. RESULTS: SD occurred in 8.8% of the patients, MG1-SSI in 6.8%. Chronic obstructive pulmonary disease (COPD) was the only independent predictor for SD (Odds Ratio, O.R. 12.1; p < 0.001); proximal sternal height (PSH) was the only independent protective factor (O.R. 0.58; p < 0.001), with a cut-off value of 11.7 mm (sensitivity 70.5%, specificity 71.0%; ROC area under the curve (AUC) = 0.768, p < 0.001). Diabetes mellitus (O.R. 3.5; p < 0.001) and COPD (O.R. 21.3; p < 0.001) were independent predictors for MG1-SSI; indexed proximal sternal height (iPSH) was as a protective factor (O.R. 0.26; p < 0.001) with a cut-off of 5.97 mm (sensitivity 70.2%, specificity 69.0%; ROC AUC = 0.739, p < 0.001). No other radiological measurements were independently correlated with SD or MG1-SS (p = N.S.). CONCLUSION: PSH and iPSH at preoperative chest X-ray may act as indicators of high risk for sternal wound complications, allowing for early preventative measures.

Correction to: Exploring the peptide retention mechanism in molecularly imprinted polymers.

The authors would like to call the reader's attention to the fact that unfortunately due to the file formatting during the exporting of the data matrix from the program Unscrambler (used for the development of the statistical model) to the Word office file.

Exploring the peptide retention mechanism in molecularly imprinted polymers.

Molecularly imprinted polymers (MIPs) have been used as useful sorbents in solid-phase extraction for a wide range of molecules and sample matrices. Their unique selectivity can be fine-tuned in the imprinting process and is crucial for the extraction of macromolecules from complex matrices such as serum. A relevant example of this is the application of MIPs to peptides in diagnostic assays. In this article the selectivity of MIPs, previously implemented in a quantitative mass-spectrometric assay for the biomarker pro-gastrin-releasing peptide, is investigated. Partial least squares regression was used to generate models for the evaluation and prediction of the retention mechanism of MIPs. A hypothesis on interactions of MIPs with the target peptide was verified by ad hoc experiments considering the relevant peptide physicochemical properties highlighted from the multivariate analysis. Novel insights into and knowledge of the driving forces responsible for the MIP selectivity have been obtained and can be directly used for further optimization of MIP imprinting strategies. Graphical Abstract Applied analytical strategy: the Solid Phase Extraction (SPE) of digested Bovin Serum Albumin (BSA), using Molecularly Imprinted Polymers (MIP), is followed by the liquid chromatography-mass spectrometry (LC-MS) analysis for the identification of the retained peptides. The further application of multivariate analysis allows setting up a Partial Least Square (PLS) model, which describes the peptide retention into the MIP and gives additional knowledge to be used in the optimization of the MIP and the whole SPE method.

Automated Protein Biomarker Analysis: on-line extraction of clinical samples by Molecularly Imprinted Polymers.

Robust biomarker quantification is essential for the accurate diagnosis of diseases and is of great value in cancer management. In this paper, an innovative diagnostic platform is presented which provides automated molecularly imprinted solid-phase extraction (MISPE) followed by liquid chromatography-mass spectrometry (LC-MS) for biomarker determination using ProGastrin Releasing Peptide (ProGRP), a highly sensitive biomarker for Small Cell Lung Cancer, as a model. Molecularly imprinted polymer microspheres were synthesized by precipitation polymerization and analytical optimization of the most promising material led to the development of an automated quantification method for ProGRP. The method enabled analysis of patient serum samples with elevated ProGRP levels. Particularly low sample volumes were permitted using the automated extraction within a method which was time-efficient, thereby demonstrating the potential of such a strategy in a clinical setting.

Filter Plate-Based Screening of MIP SPE Materials for Capture of the Biomarker Pro-Gastrin-Releasing Peptide.

Affinity-based solid-phase extraction (SPE) is an attractive low-cost sample preparation strategy for biomarker analysis. Molecularly imprinted polymers (MIPs) as affinity sorbents offer unique opportunities for affinity SPE, due to their low manufacturing cost and high robustness. A limitation is the prediction of their affinity; therefore, screening of analyte recovery and specificity within a large range of SPE conditions is important in order to ensure high-sensitivity detection and assay reproducibility. Here, a µ-SPE method for screening of the MIP-SPE materials using a commercial 384-well filter plate is presented. The method allows for rapid and automated screening using 10-30 µL of packed SPE sorbent per well and sample volumes in the range of 10-70 µL. This enables screening of many different SPE sorbents while simultaneously identifying optimal SPE conditions. In addition, the 384-well format also facilitates detection with a multitude of analytical platforms. Performance of the µ-MIP-SPE method was investigated using a series of MIPs designed to capture pro-gastrin-releasing peptide (ProGRP). Fractions coming from sample load, cartridge wash, and elution were collected and analyzed using mass spectrometry (MS). The top-performing MIPs were identified, together with proper SPE conditions.