国产隐球菌荚膜多糖胶体金法检测试剂盒性能评价

目的评价由丹娜(天津)生物科技股份有限公司生产的隐球菌荚膜多糖检测试剂盒(胶体金法,考核试剂)的检测性能。方法选取隐球菌和隐球菌近缘菌及肺部感染常见菌种共28属100株菌作为研究对象,配制0.5麦氏浊度单位(0.5 M)菌液检测试剂的特异性,0.5 M阳性的菌株以10倍倍比稀释液作为灵敏度检测菌液,以2 M和4 M浓度菌液作为钩状效应检测菌液,并以美国Immuno Mycologics公司生产的隐球菌抗原检测(胶体金免疫层析法)试剂盒作为对比试剂,比较两家试剂的一致性。结果31株隐球菌属菌株中,考核试剂检测出阳性25株(新型隐球菌和格特隐球菌均为阳性),阴性6株(维多利亚隐球菌、C.dimennae和大隐球菌);16株毛孢子菌属菌株中,检测出阳性12株,阴性4株;1株Cutaneotrichosporon curvatum检测结果为阳性;52株其他菌株的检测结果均为阴性;灵敏度实验结果显示考核试剂隐球菌最低检出限为1.0×10² CFU/mL;2 M和4 M浓度菌液均未出现钩状效应。结论考核试剂隐球菌荚膜多糖检测试剂盒(胶体金法)检测隐球菌属的灵敏度高于比对试剂;特异性方面存在一定的属内和属外交叉反应,但与对比试剂的检测结果高度一致;考核试剂与比对试剂均无钩状效应产生。     

Paper-based immunosensor with signal amplification by enzyme-labeled anti-p16INK4a multifunctionalized gold nanoparticles for cervical cancer screening

The aim of this study was to develop a paper-based immunosensor for cervical cancer screening, with signal amplification by multifunctionalized gold nanoparticles (AuNPs). The AuNPs were functionalized with a highly specific antibody to the p16^INK4a cancer biomarker. The signal was amplified using a combination of the peroxidase activity of horseradish peroxidase (HRP) enzyme-antibody conjugate and the peroxidase-like activity of the AuNPs. The immune complex of p16^INK4a protein and multifunctionalized AuNPs was deposited on the nitrocellulose membrane, and a positive result was generated by catalytic oxidation of peroxidase enzyme substrate 3,3’,5,5’-Tetramethylbenzidine (TMB). The entire reaction occurred on the membrane within 30 min. Evaluation in clinical samples revealed 85.2% accuracy with a kappa coefficient of 0.69. This proof of concept study demonstrates the successful development of a highly accurate, paper-based immunosensor that is easy to interpret using the naked eye and that is suitable for cervical cancer screening in low-resource settings.     

Gold nanoparticles conjugating recombinant influenza hemagglutinin trimers and flagellin enhanced mucosal cellular immunity

The immunogenicity of subunit vaccines can be augmented by formulating them into nanoparticles. We conjugated recombinant trimetric influenza A/Aichi/2/68(H3N2) hemagglutinin (HA) onto functionalized gold nanoparticle (AuNP) surfaces in a repetitive, oriented configuration. To further improve the immunogenicity, we generated Toll-like receptor 5 (TLR5) agonist flagellin (FliC)-coupled AuNPs as particulate adjuvants. Intranasal immunizations with an AuNP-HA and AuNP-FliC particle mixture elicited strong mucosal and systemic immune responses that protected hosts against lethal influenza challenges. Compared with the AuNP-HA alone group, the addition of AuNP-FliC improved mucosal B cell responses as characterized by elevated influenza specific IgA and IgG levels in nasal, tracheal, and lung washes. AuNP-HA/AuNP-FliC also stimulated antigen-specific interferon-γ (IFN-γ)-secreting CD4⁺ cell proliferation and induced strong effector CD8⁺ T cell activation. Our results indicate that intranasal co-delivery of antigen and adjuvant-displaying AuNPs enhanced vaccine efficacy by inducing potent cellular immune responses.     

Targeted-gene silencing of BRAF to interrupt BRAF/MEK/ERK pathway synergized photothermal therapeutics for melanoma using a novel FA-GNR-siBRAF nanosystem

Melanoma is significantly associated with mutant BRAF gene, a suitable target for siRNA-based anti-melanoma therapy. However, a tumor-specific delivery system is a major hurdle for clinical applications. Here, we developed a novel nano-carrier, FA-GNR-siBRAF for safe topical application, which consists of folic acid (FA) as the tumor-targeting moiety, golden nanorods (GNR) providing photothermal capability to kill tumor cells under laser irradiation, and siRNA specifically silencing BRAF (siBRAF). The in vitro and in vivo results revealed that FA-GNR-siBRAF displayed high transfection rates, and subsequently induced remarkable gene knockdown of BRAF, resulting in suppression of melanoma growth due to the interruption of the MEK/ERK pathway. Combinatorial photothermal effects and BRAF knockdown by FA-GNR-siBRAF effectively killed tumor cells through apoptosis, with enhanced efficiency than individual treatments. Therefore, the FA-GNR-siBRAF simultaneously induced BRAF gene silencing and photothermal effects which achieved synergistic efficacy in the treatment of melanoma, paving a new path for developing clinical treatment methods for melanoma.     

Neuroprotective effect of gold nanoparticles composites in Parkinson's disease model

Parkinson’s disease (PD) is second most common neurodegenerative disorder worldwide. Although drugs and surgery can relieve the symptoms of PD, these therapies are incapable of fundamentally treating the disease. For PD patients, over-expression of α-synuclein (SNCA) leads to the death of dopaminergic neurons. This process can be prevented by suppressing SNCA over-expression through RNA interference. Here, we successfully synthesized gold nanoparticles (GNP) composites (CTS@GNP-pDNA-NGF) via the combination of electrostatic adsorption and photochemical immobilization, which could load plasmid DNA (pDNA) and target specific cell types. GNP was transfected into cells via endocytosis to inhibiting the apoptosis of PC12 cells and dopaminergic neurons. Simultaneously, GNP composites are also used in PD models in vivo, and it can successfully cross the blood-brain barrier by contents of GNP in the mice brain. In general, all the works demonstrated that GNP composites have good therapeutic effects for PD models in vitro and in vivo.     

A novel gold nanorods-based pH-sensitive thiol-ended triblock copolymer for chemo-photothermo therapy of cancer cells

Currently an effective strategy in nanomedicine for cancer therapy is the combination of photothermal therapy with chemotherapy. Because combination cancer therapy improve the therapy efficiency by synergistic effects and overcoming drug resistance as compared to monotherapy possesses. According to these facts, gold nanorods-cored biodegradable micelles were prepared by coating gold nanorods (AuNRs) with synthesized pH-sensitive thiol-ended amphiphilic triblock copolymer (PAA-b-PDMAEMAQ-b-PCL-SH). The synthesized AuNRs@polymer was loaded with methotrexate (MTX) as an anticancer drug through electrostatic interactions to afford AuNRs@polymer-MTX. The success of the coating was investigated by means of atomic force microscopy (AFM), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-vis) spectroscopy, as well as dynamic light scattering (DLS), and zeta potential measurements. MTX-loading capacity, and pH triggered in vitro drug release behavior of the synthesized nanocomposites were also investigated. In vitro cytotoxic effects was comprehensively evaluated among free MTX, AuNRs@polymer, and AuNRs@polymer–MTX, with or without NIR light irradiation (1064?nm, 125?mJ/pulse, and 4?min) to improve curative effect of AuNRs@polymer–MTX led by the combination of photothermal therapy and chemotherapy.     

EB病毒衣壳抗原IgA抗体胶体金快速检测法的建立及应用

目的建立了一种快速检测人血清中EB病毒衣壳抗原(VCA)IgA抗体的胶体金免疫层析(GICA)方法。方法预先将EB病毒衣壳抗原(EB-VCA)包被在硝酸纤维素膜上,将鼠抗人IgA抗体免疫金固化在金标垫上。检测时,样本通过层析作用向上流动,样本中的IgA抗体首先被胶体金标记的鼠抗人IgA抗体捕获,其中的EB-VCAIgA抗体再与包被在硝酸纤维素膜上的EB-VCA特异性结合,最后形成包被固相上的EB-VCA与EB-VCAIgA抗体及胶体金标记鼠抗人IgA抗体的三元复合物,通过检测线胶体金沉淀颜色的变化来定性判定样本中是否存在EB-VCAIgA抗体。结果采用自制的GICA试纸条进行了1028份临床标本的盲法检测,并与酶联免疫吸附试验的EB-VCAIgA抗体诊断试剂盒进行比对,结果表明两种试剂检测的总符合率达到94.56%,阳性符合率为93.40%,阴性符合率为95.17%,Kappa值为0.873,两种诊断试剂具备一致的诊断价值。结论用于检测血清中的EB-VCAIgA抗体的GICA试纸条的制备条件已基本建立,其检测结果特异性强、稳定性好、操作方法简便快捷且无需特殊仪器设备。     

Gallol‐Tethered Injectable AuNP Hydrogel with Desirable Self‐Healing and Catalytic Properties

Injectable self‐healing hydrogels have drawn growing attention for their extensive applications in biomedical fields. Hydrogels containing nanoparticles also exhibit promising potentials in catalysis, wastewater treatment, and organic synthesis. Inspired by the multifunction of gallol presented herein, a simple one‐pot method to produce a gallol‐tethered gelatin hydrogel via Schiff base under oxidizing conditions using various oxidants is presented. The hydrogels prepared by NaIO₄‐induced cross‐linking present a high self‐healing rate (up to 84.5%), injectable ability, tunable mechanical property, flexible viscoelasticity, and macroporous structure owing to the combination of covalent cross‐linking and supramolecular interactions. HAuCl₄ contributes to the 3D structure formation of the gelatin hydrogel via oxidation cross‐linking. It is reduced by the gallol groups to produce nanogold (AuNP)‐decorated hydrogel (Au‐gel). This Au‐gel is fully characterized by UV–vis, XRD, TEM, SEM, EDX, and ICP‐MS and exhibits a high‐catalytic activity for the reduction of 4‐nitrophenol. The solid Au‐gel catalyst is robust, easily recyclable, and reused at least eight times.