A biolayer interferometry-based enzyme-linked aptamer sorbent assay for real-time and highly sensitive detection of PDGF-BB.

Accurate, fast and sensitive detection of disease-specific protein biomarkers, especially in blood, urine, or other bodily fluids, is an important approach to achieve early disease diagnosis. Platelet-derived growth factor-BB (PDGF-BB), a widely used biomarker, is involved in a substantial number of serious diseases, such as hepatic fibrosis, atherosclerosis, age-related macular degeneration and diabetic eye disease and is often over-expressed in human malignant tumors. Therefore, the development of sensitive and specific detection methods for PDGF-BB is of great importance for the early diagnosis of disease and assessments of patient recovery. In the current study, a biolayer interferometry-based enzyme-linked aptamer sorbent assay (BLI-ELASA) was successfully established for rapid (20-25min), high-throughput (8 or 16 samples) and real-time monitoring of PDGF-BB in clinical samples. The method exhibited a broad detection range from 0.5 to 1000ng/mL of PDGF-BB (good linear range from 0.5 to 10ng/mL), with a low detection limit of 0.08ng/mL. Moreover, BLI-ELASA was applied to the detection of PDGF-BB in spiked serum and urine samples and showed a high degree of selectivity for PDGF-BB, good reproducibility, and stability. We believe that the methodology in this work can be easily adapted to detect other biomolecules in clinical samples, including viruses, pathogens and toxins, in a rapid, sensitive, high-throughput and real-time manner.

A luminol electrochemiluminescence aptasensor based on glucose oxidase modified gold nanoparticles for measurement of platelet-derived growth factor BB.

A sandwich-type luminol electrochemiluminescence (ECL) aptasensor for highly sensitive and selective detection of platelet-derived growth factor BB (PDGF-BB) is fabricated. For this proposed ECL aptasensor, a multilayered AuNPs-electrochemically reduced graphene (AuNPs-EG) nanocomposite film was formed on the GCE surface as the base of the aptasensor through a co-electrodeposition method. The AuNPs-EG composites possess high conductivity to promote the electron transfer at the electrode interface and good biocompatibility and large surface area to capture large amounts of primary aptamer (Apt1), thus amplifying the detection response. Moreover, glucose oxidase (GOD) functionalized AuNPs labeled secondary aptamer (GOD-Apt2-AuNPs) was designed as the signal probe for the sandwiched aptasensor. Enhanced sensitivity was obtained by in situ generation of H2O2 from reaction between GOD and glucose and the excellent catalytic behavior of AuNPs to the ECL of the luminol-H2O2 system. Under the optimal conditions, the as-prepared ECL aptasensor exhibited excellent analytical property for the detection of PDGF-BB in the range from 1.0×10(-13) to 5.0×10(-10) mol L(-1) with a detection limit of 1.7×10(-14) mol L(-1) (S/N=3). The application of the present protocol was demonstrated by analyzing PDGF-BB in human serum and human urine samples with the recoveries from 85.0% to 110%.

Urinary platelet-derived growth factor-BB as an early marker of nephropathy in patients with type 2 diabetes: an Egyptian study.

BACKGROUND: Diabetic nephropathy (DN) is one of the most serious complications of diabetes worldwide. Strong evidence suggests that several growth factors may contribute to the initiation and progressive fibrosis of DN. Recently, there is an overexpression of platelet-derived growth factor (PDGF) in renal biopsies from patients with DN. This study aimed to investigate the clinical significance of urinary PDGF-BB level in type 2 diabetic patients with and without nephropathy and to evaluate its relationship with various clinical and laboratory parameters. METHODS: Urinary levels of PDGF-BB were measured in 60 Egyptian type 2 diabetic patients categorized into three equal groups (normo-, micro-, and macroalbuminuria), according to urinary albumin level. In addition, 20 healthy subjects were selected to serve as controls. RESULTS: The urinary PDGF-BB levels were significantly increased in type 2 diabetic patients as compared to controls (p < 0.001). Moreover, diabetics with micro- and macroalbuminuria had significantly higher levels than in those with normoalbuminuria (p < 0.001). Urinary PDGF-BB correlated positively with disease duration, low-density lipoprotein (LDL)-cholesterol, and urinary albumin and negatively with creatinine clearance in diabetic patients. In a multiple regression model, urinary PDGF-BB was strongly and independently associated with nephropathy in diabetic patients (ß = -0.03, p < 0.001). CONCLUSIONS: PDGF-BB may play an important role in the initiation and progression of DN. It is considered as a good predictor for early deterioration of renal function in DN. Thus, measurement of urinary PDGF-BB in type 2 diabetic patients could be used for early detection of diabetic renal disease.

[Expression and clinical implication of platelet-derived growth factor-D and platelet-derived growth factor-beta in childhood IgA nephropathy].

OBJECTIVE: To investigate the clinical implication of platelet-derived growth factor (PDGF)-D and PDGF-beta in IgA nephropathy in childhood. METHODS: Forty-seven children with IgA nephropathy and 26 controls were enrolled for study, and their serum, urine and renal biopsy specimens were examined. The patients were divided into control group [including serum, urine specimens of 13 healthy children and 13 renal biopsy samples of non-IgA nephropathy in children], mild proliferation (MP) group (13 patients), focal proliferation (FP) group (19 patients), and proliferation sclerosis (PS) group (15 patients). Enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry were used to determine contents of PDGF-D, PDGF-beta and PDGF-B in blood, urine and renal tissues. The levels of 24-hour urinary protein excretion, serum albumin (Alb), serum blood urea nitrogen (BUN) and creatinine (Cr) were also determined. RESULTS: Compared with control group, levels of PDGF-D and PDGF-B were progressively elevated in blood and urine of IgA nephropathy children with increase in severity of glomerular damage (all P<0.01). Serum as well as urinary PDGF-D and PDGF-B levels were positively correlated with 24-hour urinary protein excretion (PDGF-D blood: r=0.546, urine: r=0.760; PDGF-B blood: r=0.634, urine: r=0.577, respectively, P<0.01), while negatively correlated with serum Alb levels in IgA nephropathy patients (PDGF-D blood: r=-0.649, urine: r=-0.528; PDGF-B blood: r=-0.613, urine: r=-0.531, respectively, P<0.01). Contents of PDGF-D and PDGF-beta in renal tissue were much higher than those of control group (P<0.01). Along with the increase in severity of glomerular pathology, their contents increased gradually. PDGF-B was only significantly expressed in renal tissue in FP group and PS group. CONCLUSION: PDGF-D might significantly enhance the development of mesangial proliferation and tubulointerstitial fibrosis. In comparison with PDGF-B, PDGF-D appears to reflect more sensitive to the severity and prognosis of IgA nephropathy.