Investigation the influence of ar plasma treatment on cell response for wet-spun starch/polycaprolactone fiber mesh scaffolds

In design of a tissue engineering scaffold, surface physicochemistry is one of the most important issues to be considered. The physicochemical properties of the surface directly influence the scaffold performance by affecting the cellular response and ultimately effecting the new tissue formation. In order to improve the cell affinity, the surface hydrophiliticy, surface energy, surface roughness and surface charge can be modify by different methods. Plasma treatment is a versatile method for surface treatment of biodegradable polymers without altering their bulk properties. By this method, it is possible to introduce or graft desired functional groups onto the surface. This study aims to investigate the influence of Ar plasma treatment on osteablast cell response for fiber mesh scaffolds from a starch-polycaprolactone blend. [...]info:eu-repo/semantics/publishedVersio

Nano/microparticle incorporated chitosan fibers as tissue engineering scaffolds

[Excerpt] The aim of this study was to develop a bone tissue engineering scaffold with an inherent bone morphogenetic proteins BMP-2 and BMP-7 sequential delivery system. BMPs were encapsulated in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and poly(lactic acid-co-glycolic acid) (PLGA) nano/microparticules which are then introduced to a chitosan matrix by two methods: embedding in the chitosan fibers and then forming the scaffold or by forming the chitosan scaffold and then introducing the nano/microparticules. [...]info:eu-repo/semantics/publishedVersio

A novel enzymatically-mediated drug delivery carrier for bone tissue engineering applications: combining biodegradable starch-based microparticles and differentiation agents

In many biomedical applications, the performance of biomaterials depends largely on their degradation behavior. For instance, in drug delivery applications, the polymeric carrier should degrade under physiological conditions slowly releasing the encapsulated drug. The aim of this work was, therefore, to develop an enzymaticmediated degradation carrier system for the delivery of differentiation agents to be used in bone tissue engineering applications. For that, a polymeric blend of starch with polycaprolactone (SPCL) was used to produce a microparticle carrier for the controlled release of dexamethasone (DEX). In order to investigate the effect of enzymes on the degradation behavior of the developed system and release profile of the encapsulated osteogenic agent (DEX), the microparticles were incubated in phosphate buffer solution in the presence of a-amylase and/or lipase enzymes (at physiological concentrations), at 37 C for different periods of time. The degradation was followed by gravimetric measurements, scanning electron microscopy (SEM) and Fourier transformed infrared (FTIR) spectroscopy and the release of DEX was monitored by high performance liquid chromatography (HPLC). The developed microparticles were shown to be susceptible to enzymatic degradation, as observed by an increase in weight loss and porosity with degradation time when compared with control samples (incubation in buffer only). For longer degradation times, the diameter of the microparticles decreased significantly and a highly porous matrix was obtained. The in vitro release studies showed a sustained release pattern with 48% of the encapsulated drug being released for a period of 30 days. As the degradation proceeds, it is expected that the remaining encapsulated drug will be completely released as a consequence of an increasingly permeable matrix and faster diffusion of the drug. Cytocompatibility results indicated the possibility of the developed microparticles to be used as biomaterial due to their reduced cytotoxic effects

Role of transforming growth factor-β2 in, and apossible transforming growth factor-β2 gene polymorphism as a marker of, renal dysfunction in essential hypertension: A study in Turkish patients

AbstractBackground:Many studies have shown that transforming growth factor(TGF)-β has a major role in renal scarring in many renal diseases and hypertension.Objectives:The primary aim of this study was to investigate both the relationship between hypertension and serum and urinary levels of TGF-β2 (a more sensitive isoform for glomeruli than TGF-β1), and the effects of combination therapy with perindopril + indapamide on microalbuminuria, which becomes an early indicator of hypertensive benign nephropathy, and serum and urinary TGF-β2 levels in patients with mild to moderate essential hypertension. In addition, we examined the possible relationship between TGF-β2 gene polymorphism and essential hypertension.Methods:This study was conducted at the Department of Nephrology, Medical Faculty, Gazi University, Ankara, Turkey. Patients aged ≥18 years with newly diagnosed mild to moderate essential hypertension (systolic/diastolic blood pressure [SBP/DBP] >120/>80 mm Hg) who had not previously received antihypertensive treatment were included in the study. Patients with stage I hypertension received perindopril 2 mg + indapamide 0.625 mg (tablet), and patients with stage lI hypertension received perindopril 4 mg + indapamide 1.125 mg (tablet). All study drugs were given OD (morning) PO with food for 6 months. Serum and urinary TGF-β2 and creatinine levels and serum and urinary albumin levels were measured before and after perindopril + indapamide administration. Amplified DNA fragments of the TGF-β2 primer region were screened using amplification refractory mutation system polymerase chain reaction analysis, and the number of ACA repeats was confirmed by DNA sequencing. Genetic studies were performed using a commercial TGF-β2 kit.Results:Forty patients were enrolled in the study, and 38 patients (27 women, 11 men; mean [SD] age, 46.3 [6.5] years) completed it. SBP and DBP were significantly decreased from baseline with perindopril/indapamide (both, P < 0.001). Microalbuminuria and urinary TGF-β2 levels also decreased significantly from baseline (P = 0.04 and P < 0.001, respectively), whereas the serum TGF-β2 level did not change significantly. Three patients, all of whom were found to have TGF-β2 gene mutations, had increased urinary TGF-β2 levels despite good blood pressure control.Conclusions:The results of this study in patients with mild to moderate hypertension suggest that, despite good clinical control of blood pressure, the persistence of microalbuminuria and high urinary TGF-β2 levels might predict renal impairment. When treating these patients, genetic tendencies and possible polymorphisms on the TGF-β2 locus should be kept in mind

Role of transforming growth factor-beta(2) in, and a possible Transforming Growth Factor-beta(2) gene polymorphism as a marker of, renal dysfunction in essential hypertension: A study in Turkish patients

WOS: 000231920000002PubMed: 24672129Background: Many studies have shown that transforming growth factor (TGF)-beta has a major role in renal scarring in many renal diseases and hypertension. Objectives: The primary aim of this study was to investigate both the relationship between hypertension and serum and urinary levels of TGF-beta(2) (a more sensitive isoform for glomeruli than TGF-beta(1))), and the effects of combination therapy with perindopril + indapamide on microalbuminuria, which becomes an early indicator of hypertensive benign nephropathy, and serum and urinary TGF-beta(2) levels in patients with mild to moderate essential hypertension. In addition, we examined the possible relationship between TGF-beta(2) gene polymorphism and essential hypertension. Methods: This study was conducted at the Department of Nephrology, Medical Faculty, Gazi University, Ankara, Turkey. Patients aged >= 18 years with newly diagnosed mild to moderate essential hypertension (systolic/diastolic blood pressure [SBP/DBP] > 120/> 80 mm Hg) who had not previously received antihypertensive treatment were included in the study. Patients with stage I hypertension received perindopril 2 mg + indapamide 0.625 mg (tablet), and patients with stage 11 hypertension received perindopril 4 mg + indapamide 1.125 mg (tablet). All study drugs were given OD (morning) PO with food for 6 months. Serum and urinary TGF-beta(2) and creatinine levels and serum and urinary albumin levels were measured before and after perindopril + indapamide administration. Amplified DNA fragments of the TGF-beta(2) primer region were screened using amplification refractory mutation system polymerase chain reaction analysis, and the number of ACA repeats was confirmed by DNA sequencing. Genetic studies were performed using a commercial TGF-beta(2) kit. Results: Forty patients were enrolled in the study, and 38 patients (27 women, 11 men; mean [SD] age, 46.3 [6.5] years) completed it. SBP and DBP were significantly decreased from baseline with perindopril/indapamide (both, P < 0.001). Microalbuminuria and urinary TGF-beta(2) levels also decreased significantly from baseline (P = 0.04 and P < 0.001, respectively), whereas the serum TGF-beta(2) level did not change significantly. Three patients, all of whom were found to have TGF-beta(2) gene mutations, had increased urinary TGF-beta(2) levels despite good blood pressure control. Conclusions: The results of this study in patients with mild to moderate hypertension suggest that, despite good clinical control of blood pressure, the persistence of microalbuminuria and high urinary TGF-beta(2) levels might predict renal impairment. When treating these patients, genetic tendencies and possible polymorphisms on the TGF-beta(2) locus should be kept in mind

Novel biodegradable polymeric microparticles for the localized delivery of differentiation agents in bone tissue engineering applications

[Excerpt] Growth and differentiation factors can be used to guide the biology in tissue engineering, ranging from promoting cell proliferation, to morphogenic activities initiating a cascade of events leading to tissue formation in vivo. Synthetic glucocorticoids (e.g. dexamethasone, DEX) and bone morphogenetic proteins (BMPs) are particularly relevant in bone tissue engineering, as they are able to induce osteoblastic differentiation. In this work, starch-poly-e-caprolactone (SPCL) microparticles were developed as a matrix for the controlled release of DEX and BMP-2. The developed system was characterized in terms of morphology and size distribution. DEX and BMP-2 were entrapped into SPCL microparticles at different percentages. The loading and encapsulation efficiency, as well as their release profile, were evaluated by HPLC and ELISA quantification. [...]info:eu-repo/semantics/publishedVersio

The relationship between vascular endothelial growth factor (VEGF) and microalbuminuria in patients with essential hypertension

WOS: 000259221300003PubMed: 18758126Objective The existence of microalbuminuria (MAU) in patients with essential hypertension is a strong indicator of microvascular damage. Although endothelial dysfunction and increased vascular permeability both have a role in the development of MAU, its ethiopathogenesis in hypertensive patients is not yet clearly understood. Vascular endothelial growth factor (VEGF) is the most important regulator of pathological or physiological angiogenesis and it additionally leads to increased vascular permeability. This study aims to assess the relationship of serum VEGF levels to MAU in non-complicated, newly-diagnosed essential hypertensive patients (EHs). Methods This study included 30 newly-diagnosed EHs with MAU, 46 newly-diagnosed EHs without MAU and 46 healthy controls. None of the EHs had diabetes, renal impairment or atherosclerotic diseases. Serum VEGF levels were measured using the ELISA method. Results Serum levels of VEGF were significantly higher in EHs with MAU when compared with patients without MAU (225.15+/-109.34 pg/mL versus 166.78+/-114.35 pg/mL, p: 0.04) or controls (225.15+/-109.34 pg/mL versus 144.91+/-96.60 pg/mL, p: 0.007). On the other hand, no significant difference was observed between the non-MAU and control groups. In the univariate analysis, serum levels of VEGF, were positively correlated with systolic blood pressure (R: 0.253 p: 0.001), diastolic blood pressure (R: 0.162 p: 0.04), mean arterial pressure (R: 0.239 p: 0.002), creatinine clearance (R: 0.172 p: 0.04) and MAU (R: 0.338 p: 0.002). In the multiple linear regression analysis, VEGF levels were independently related to MAU (beta: 0.248, p: 0.02). Conclusion VEGF levels are higher in EHs in the presence of MAU. These high values may be important in the early diagnosis of vascular damage in EHs. Additionally, VEGF may increase glomerular permeability and lead to MAU in EHs

Peritonitis and Risk Factors in Peritoneal Dialysis Patients

The aim of this study was to evaluate the frequency, risk factors and treatment outcomes in continuous ambulatory peritoneal dialysis (CAPD) patients with peritonitis. Fifty-five CAPD patients followed in our peritoneal dialysis unit between January 2000-September 2003 were enrolled. Data of the patients included demographic properties, educational status, symptoms at diagnosis, physical examination findings, laboratory findings, results of peritoneal fluid cultures and the treatment was given to the patients at the beginning were collected retrospectively from their hospital files. Of the 55 patients on PD 35 peritonitis episodes was found in 23 (41.8%) patients, and tunnel infections in 4 (7.2%) patients. The most common presenting complaints of the patients with an average of 29 months prevalence of peritonitis included abdominal pain and tenderness. In 9 (25.7%) patients with peritonitis, a microorganism has been isolated from their peritoneal fluid. Of the patients experiencing peritonitis 5 (21.7%) were changed to hemodialysis while 2 (8.6%) lost their lives. Diabetes mellitus and the first 12 months of the peritoneal dialysis were determined to be risk factors for episodes of peritonitis. Peritonitis is still continues to be an important problem for the dialysis patient group. Because of the increased risk in diabetic patients and those starting peritoneal dialysis for the first time careful follow up is necessary