Cryogels-versatile tools in bioseparation.

Cryogels are polymeric materials formed from monomeric or polymeric precursors in moderately frozen state by polymerization or crosslinking. The process applied for cryogel formation is called cryogelation. These macroporous gel matrices can be produced with different shapes and the gels are of interest in the bioseparation area since they can meet needs that conventional chromatographic media are less suitable to fulfill. High porosity, high mechanical and chemical stability make them appropriate carriers for immobilization of biomolecules and cells thereby making them attractive gel matrices for separation and purification of various molecules. This review highlights the preparation and properties of cryogels, and applications of these materials especially in bioseparation science

Highly sensitive detection and quantification of the secreted bacterial benevolence factor RoxP using a capacitive biosensor : A possible early detection system for oxidative skin diseases

The impact of the microbiota on our health is rapidly gaining interest. While several bacteria have been associated with disease, and others being indicated as having a probiotic effect, the individual biomolecules behind these alterations are often not known. A major problem in the study of these factors in vivo is their low abundance in complex environments. We recently identified the first secreted bacterial antioxidant protein, RoxP, from the skin commensal Propionibacterium acnes, suggesting its relevance for maintaining the redox homeostasis on the skin. In order to study the effect, and prevalence, of RoxP in vivo, a capacitive biosensor with a recognition surface based on molecular imprinting was used to detect RoxP on skin in vivo. In vitro analyses demonstrated the ability to detect and quantify RoxP in a concentration range of 1 x 10(-13) M to 1 x 10(-8) M from human skin swabs; with a limit of detection of 2.5 x 10(-19) M in buffer systems. Further, the biosensor was highly selective, not responding to any other secreted protein from P. acnes. Thus, it was possible to demonstrate the presence, and quantity, of RoxP on human skin. Therefore, the developed biosensor is a very promising tool for the detection of RoxP from clinical samples, offering a rapid, cost-effective and sensitive means of detecting low-abundant bacterial proteins in vivo in complex milieus

Real-time prostate-specific antigen detection with prostate-specific antigen imprinted capacitive biosensors

Prostate specific antigen (PSA) is a valuable biomarker for early detection of prostate cancer, the third most common cancer in men. Ultrasensitive detection of PSA is crucial to screen the prostate cancer in an early stage and to detect the recurrence of the disease after treatment. In this report, microcontact-PSA imprinted (PSA-MIP) capacitive biosensor chip was developed for real-time, highly sensitive and selective detection of PSA. PSA-MIP electrodes were prepared in the presence of methacrylic acid (MAA) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as the cross-linker via UV polymerization. Immobilized Anti-PSA antibodies on electrodes (Anti-PSA) for capacitance measurements were also prepared to compare the detection performances of both methods. The electrodes were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM) and cyclic voltammetry (CV) and real-time PSA detection was performed with standard PSA solutions in the concentration range of 10 fg mL(-1) -100 ng mL(-1). The detection limits were found as 8.0 x 10(-5) ng mL(-1) (16 x 10(-17) M) and 6.0 x 10(-4) ng mL(-1) (12 x 10(-16) M) for PSA-MIP and Anti-PSA electrodes, respectively. Selectivity studies were performed against HSA and IgG and selectivity coefficients were calculated. PSA detection was also carried out from diluted human serum samples and finally, reproducibility of the electrodes was tested. The results are promising and show that when the sensitivity of the capacitive system is combined with the selectivity and reproducibility of the microcontact-imprinting procedure, the resulting system might be used successfully for real-time detection of various analytes even in very low concentrations. (C) 2015 Elsevier B.V. All rights reserved

Microcontact imprinting based surface plasmon resonance (SPR) biosensor for real-time and ultrasensitive detection of prostate specific antigen (PSA) from clinical samples

Prostate specific antigen (PSA) is an important biomarker for diagnosis and prognosis of prostate cancer. Herein, microcontact PSA-imprinted surface plasmon resonance (SPR) sensor chip was developed for sensitive, real-time detection of PSA. The imprinted chip was prepared in the presence of methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker via UV polymerization using microcontact imprinting technique. PSA imprinted SPR sensor chip was characterized by atomic force microscope (AFM), scanning electron microscope (SEM), ellipsometry, dispersive Raman and Fourier transform infrared spectroscopy (FT-IR). Under optimal conditions, PSA detection was performed with standard PSA solutions in the concentration range of 0.1-50 ng mL(-1) with a detection limit (LOD) of approximately 91 pg mL(-1) (18 x 10(-14) M). Selectivity studies were performed against human serum albumin (HSA) and lysozyme (Lyz) as the competitive agents. The developed system was evaluated for analysis of 10 clinical serum samples and showed approximately 98% agreement between the results obtained by commercial enzyme-linked immunosorbent assay (ELISA) method without significant differences at the 0.05 significance level (p = 0.751, p >0.05). (C) 2015 Elsevier B.V. All rights reserved

Clinical Correlates of Ambulatory Blood Pressure Phenotypes at a Tertiary Care Hospital in Turkey

Background/Aims: Hypertension and its complications are major public health issues worldwide due to their association with high cardiovascular morbidity and mortality. Despite significant progress in health, the prevalence of hypertension is increasing. Ambulatory blood pressure monitoring (ABPM) is becoming increasingly important for the management of hypertension. In this study, we aimed to investigate the clinical and laboratory correlates of ambulatory blood pressure (ABP) phenotypes at a tertiary care hospital in Turkey. Methods: The characteristics of 1053 patients were retrospectively obtained from the hospital database. Hypertension was defined as patients with office blood pressure (BP) ≥140/90 mmHg and/or previously diagnosed hypertension and/or the use of antihypertensive medication. According to the office BP and ABPM results patients were identified namely: (1) sustained normotensive (SNT) patients (both office BP and ABPM were normal), (2) sustained hypertensive (SHT) patients (both office BP and ABPM were high), (3) masked hypertensive (MHT) patients (office BP were normal, but ABPM were high), (4) white coat hypertensive (WCHT) patients (office BP were above limits, but ABPM were normal). Results: A total of 1053 patients were included to the study (female/male: 608/445 and mean age 55 ± 15 years). The mean age of patients with hypertension was significantly higher than without hypertension (p< 0.0001). Hypertension was more frequent in females (p=0.009). The rates of history of diabetes mellitus (DM), hyperlipidemia (HL), and chronic kidney disease (CKD) were higher in patients with hypertension (p< 0.0001). Among patients with hypertension (n=853, 81%), ABPM results showed that 388 (45%) of patients had SHT, 92 (11%) had MHT, and 144 (17%) had WCHT, whereas 229 (27%) had SNT. Patients with MHT were significantly older than patients with SNT (p=0.025). The prevalence of SHT was higher in men than in women, whereas the prevalence of WCHT was higher in women than in men (p< 0.0001). There was no significant difference between 4 groups with regard to body mass index (p=0.142), a history of DM (p=0.189) and smoking status (self-reported) (p=0.306). Patients with SHT had the highest prevalence of history of hypertension, HL and CKD (p< 0.0001). Among patients without hypertension, 26 (13%) of patients had MHT and none of those patients was on antihypertensive treatment. Conclusion: Potential usages of ABPM in Turkey may include screening of high risk individuals who have traditional cardiovascular risk factors. It also provides clinicians valuable information on abnormal ABP phenotypes. Future studies are needed to clarify the risk factors of different ABP phenotypes and to evaluate the role of ABPM on detection and control of hypertension

Clinical and molecular evaluation of MEFV gene variants in the Turkish population: a study by the National Genetics Consortium

Familial Mediterranean fever (FMF) is a monogenic autoinflammatory disorder with recurrent fever, abdominal pain, serositis, articular manifestations, erysipelas-like erythema, and renal complications as its main features. Caused by the mutations in the MEditerranean FeVer (MEFV) gene, it mainly affects people of Mediterranean descent with a higher incidence in the Turkish, Jewish, Arabic, and Armenian populations. As our understanding of FMF improves, it becomes clearer that we are facing with a more complex picture of FMF with respect to its pathogenesis, penetrance, variant type (gain-of-function vs. loss-of-function), and inheritance. In this study, MEFV gene analysis results and clinical findings of 27,504 patients from 35 universities and institutions in Turkey and Northern Cyprus are combined in an effort to provide a better insight into the genotype-phenotype correlation and how a specific variant contributes to certain clinical findings in FMF patients. Our results may help better understand this complex disease and how the genotype may sometimes contribute to phenotype. Unlike many studies in the literature, our study investigated a broader symptomatic spectrum and the relationship between the genotype and phenotype data. In this sense, we aimed to guide all clinicians and academicians who work in this field to better establish a comprehensive data set for the patients. One of the biggest messages of our study is that lack of uniformity in some clinical and demographic data of participants may become an obstacle in approaching FMF patients and understanding this complex disease