Impedimetric Immunosensor Utilizing Polyaniline/Gold Nanocomposite-Modified Screen-Printed Electrodes for Early Detection of Chronic Kidney Disease.

The presence of small amounts of human serum albumin (HSA) in urine or microalbuminuria (30-300 µg/mL) is a valuable clinical biomarker for the early detection of chronic kidney disease (CKD). Herein, we report on the development of an inexpensive and disposable immunosensor for the sensitive, specific, and label-free detection of HSA using electrochemical impedance spectroscopy (EIS). We have utilized a simple one-step screen-printing protocol to fabricate the carbon-based three-electrode system on flexible plastic substrates. To enable efficient antibody immobilization and improved sensitivity, the carbon working electrode was sequentially modified with electropolymerized polyaniline (PANI) and electrodeposited gold nanocrystals (AuNCs). The PANI matrix serves as an interconnected nanostructured scaffold for homogeneous distribution of AuNCs and the resulting PANI/AuNCs nanocomposite synergically improved the immunosensor response. The PANI/AuNCs-modified working electrode surface was characterized using scanning electron microscopy (SEM) and the electrochemical response at each step was analyzed using EIS in a ferri/ferrocyanide redox probe solution. The normalized impedance variation during immunosensing increased linearly with HSA concentration in the range of 3-300 µg/mL and a highly repeatable response was observed for each concentration. Furthermore, the immunosensor displayed high specificity when tested using spiked sample solutions containing different concentrations of actin protein and J82 cell lysate (a complex fluid containing a multitude of interfering proteins). Consequently, these experimental results confirm the feasibility of the proposed immunosensor for early diagnosis and prognosis of CKD at the point of care.

Electrochemical immunosensor utilizing electrodeposited Au nanocrystals and dielectrophoretically trapped PS/Ag/ab-HSA nanoprobes for detection of microalbuminuria at point of care.

In this study, we have fabricated a simple disposable electrochemical immunosensor for the point of care testing of microalbuminuria, a well-known clinical biomarker for the onset of chronic kidney disease. The immunosensor is fabricated by screen-printing carbon interdigitated microelectrodes on a flexible plastic substrate and utilizes electrochemical impedance spectroscopy to enable direct and label free immunosensing by analyzing interfacial changes on the electrode surface. To improve conductivity and biocompatibility of the screen-printed electrodes, we have modified it with gold nanoparticles, which are electrodeposited using linear sweep voltammetry. To enable efficient immobilization of HSA antibodies, we have developed novel PS/Ag/ab-HSA nanoprobes (polystyrene nanoparticle core with silver nanoshells covalently conjugated to HSA antibodies), and these nanoprobes are trapped on the electrode surface using dielectrophoresis. Each immunosensor has two sensing sites corresponding to test and control to improve specificity by performing differential analysis. Immunosensing results show that the normalized impedance response is linearly dependent on albumin concentration in the clinically relevant range with good repeatability. We have also developed a portable impedance readout module that can analyze the data obtained from the immunosensor and transmit it wirelessly for cloud computing. Consequently, the developed immunosensing platform can be extended to the detection of a range of immunoreactions and shows promise for point of diagnosis and public healthcare monitoring.

Impact of incompatible killer cell immunoglobulin-like receptor and its ligand on the outcome of haploidentical bone marrow transplantation.

The purpose of study was to investigate the impact of killer immunoglobulin-like receptor (KIR) and its ligand on haploidentical bone marrow transplantation. 74 cases were analyzed for the distribution frequencies and characteristics of KIR and its ligand as well as the impact of KIR ligand for the haploidentical bone marrow transplantation in terms of the overall survival, disease-free survival (DFS), GVHD and relapse. The results showed that among the 19 KIR genotypes currently nominated KIR2DL1, KIR2DL4 and KIR3DL2-3 could be detected in all the cases. Other high frequency genotypes included KIR3DP1 (98.6%), KIR2DP1 (98.6%), KIR3DL1 (97.3%) and KIR2DL3 (97.3%). Inhibitory receptor genotypes were 1.37-fold of activating receptor genotypes. KIR2DL1, KIR3DL2, KIR3DL3 and KIR2DL4 were found in all haplotypes and at least one genotype of KIR2DL2 and/or KIR2DL3 existed in all haplotypes. Among the 14 genotypes found in the test, the HLA-Cw7 was the most popular (37.8%) and the group 2 (HLA-Cw1, 3, 7, 8, 13, 14) recognized by KIR2DL2/2DL3 counted for 43.2%. The incompatibility of KIR for 32 cases of haploidentical BMT was 43.8%, of which 9/14 were KIR2DL incompatible, 5/14 were KIR2DL2 or KIR3DL1 incompatible. Among the 46 cases of haploidentical BMT, 29 cases were HLA-Cw matched and 14 cases were mismatched. The completed mismatch ratio of HLA-Cw was 30.4% and the match ratio was 63.4%. The survival rate was higher for the 14 cases of KIR genotype compatible group than the 13 cases of KIR genotype incompatible group (p = 0.032). The disease-free survival was significantly higher for the 17 cases of mismatched KIR ligands (HLA-Cw) group than the matched group (p = 0.024). The survival rate was higher in GVHD group than that in non-GVHD group when the KIR ligand was missing. The acute and severe GVHD was related to the existence of activating receptor of KIR2DS1/2DS2. The incompatibility group was accompanied with frequent acute and severe GVHD and less relapse and vice versa for the compatibility group. One patient died after BMT among the 14 mismatched KIR ligand group suffering from myelogenous leukemia while 4 patients out of 12 patients died in the matched group. It is concluded that the haploidentical BMT is characterized by mismatch between donor and recipient and its immunological reactions also features by the incompatibility of KIR genotype and missing ligand. The missing ligand for the donor KIR has strong effect on the outcome of BMT and it means a lot to analyze the KIR genotype and its ligand for the selection of best donor and prognostic evaluation in haploidentical BMT.

[Donor peripheral blood mononuclear cell infusion (DMNCI) for treatment of patients with relapsed leukemia after haploidentical bone marrow transplantation].

This study was aimed to investigate the therapeutic effect of growth factor-primed donor peripheral mononuclear stem cell infusion (DMNCI) for patients with relapsed leukemia after haploidentical bone marrow transplantation (BMT). The donor was the same individual for both BMT and DMNCI. All the three patients described here were Philadelphia chromosome positive leukemia before haploidentical BMT; one case was newly diagnosed as acute lymhoblastic leukemia (ALL) and the others were chronic myeloid leukemia (CML). Two cases (one with ALL and one with CML) manifested with clinical relapse and the third case was in the stage of molecular relapse. The former 2 patients received a single bulk dose of DMNCI, the inoculums of which contained mononuclear cells of 8.25 x 10(8)/kg or 5.24 x 10(8)/kg and CD3-positive cells of 1.87 x 10(8)/kg or 1.14 x 10(8)/kg respectively. The third case received initial dose of DMNCI which was 2.0 x 10(7)/kg, and received CD3 positive cells of 1.1 x 10(7)/kg. The results indicated that the different therapeutic responses were found in all three patients. Two patients with clinical relapse received temporal remission, and died of severe graft versus host disease (GVHD), relapse and failure at day 41 and 49 after DMNCI. The third patient with molecular relapse received molecular remission after 2 infusions of DMNCI. All three patients developed acute GVHD, but two patients among them developed GVHD of grad IV, other one developed GVHD of grad I and has survived in disease-free state during half a year follow-up. It is concluded that the DMNCI may be effective for the treatment of relapsed leukemia after haploidentical BMT and this treatment can be safe if the initial dose of DMNCI is 10(7)/kg and subsequent single dose of DMNCI gradually increases.