Academic literature on the topic 'Antibody-functionalised nanoparticles'

Spherical gold nanoparticles (5-nm diameter) were modified with a small-molecule thiolated bisphenol A (BPA) ligand to achieve an estimated coverage of ~3.3 × 10–10 mol cm–2, or 180 ligands per particle. The modified particles were tested in an enzyme-linked immunosorbent assay (ELISA) format to measure functionality and were shown to bind specifically to anti-BPA antibody while resisting the non-specific adsorption of an antibody with no affinity for BPA. It was found that the use of 10 % ethanol as a co-solvent was required in the ELISA as aqueous buffers alone resulted in poor binding between anti-BPA antibody and the functionalised nanoparticles. This is likely due to the hydrophobic nature of the BPA ligand limiting its solubility, and therefore its availability for antibody interactions, in purely aqueous environments. To our knowledge, this is the first example of a nanoparticle modified with a small organic molecule being used in an ELISA assay.

Background: Foot and mouth disease (FMD) is caused by a virus of the genus Aphthovirus, family Picornaviridae which includes several members of medical importance, Multiple subtypes or antigenic variants within each serotype, which make the vaccine from one serotype does not confer protection against the other serotype. Methods: Green synthesized silver nanoparticles were functionalized with FMDV antigen /antibody. The functionalized silver nanoparticles were characterized by UV -Visible spectrophotometer, Fluorescence Spectrophotometer etc. Immunomodulation study, efficacy and toxicity tests on the final product were carried out. Results: The protein profile after immunoprecipitation with AntiFMD antibody analysed on a 12.5% SDS-PAGE which corresponded to the viral proteins. The western blot analysis confirmed the same pattern. When the infected mice were treated with functionalised silver nanoparticles, all mice were recovered from the disease within 12 hrs. The field trial of these nanoformulations showed 100% recovery of the animals with minimum neutralizing antibody without any other physiological problems. Conclusion: Surface modification of silver nanoparticles can create multifunctional materials with potential applications. Nanoformulations developed by functionalizing whole FMD viral protein /antibody with that of silver nanoparticles, elicite an optimal immuno-protective response and as diagnostic agent against foot and mouth disease causing virus The easy method of preparation of nanoparticle, the flexibility of functionalization techniques, long shelf life without cold chain protection and minimum single low dosage reveals the feasibility of this nanoformulation applications ranging from prophylactic vaccines, diagnostics, therapy for all infections leading to autoimmune diseases.

Melanoma is highly aggressive and is known to be efficient at resisting drug-induced apoptotic signals. Resection is currently the gold standard for melanoma management, but it only offers local control of the early stage of the disease. Metastatic melanoma is prone to recurrence, and has a poor prognosis and treatment response. Thus, the need for advanced theranostic alternatives is evident. Photodynamic therapy has been increasingly studied for melanoma treatment; however, it relies on passive drug accumulation, leading to off-target effects. Nanoparticles enhance drug biodistribution, uptake and intra-tumoural concentration and can be functionalised with monoclonal antibodies that offer selective biorecognition. Antibody–drug conjugates reduce passive drug accumulation and off-target effects. Nonetheless, one limitation of monoclonal antibodies and antibody–drug conjugates is their lack of versatility, given cancer’s heterogeneity. Monoclonal antibodies suffer several additional limitations that make recombinant antibody fragments more desirable. SNAP-tag is a modified version of the human DNA-repair enzyme, O6-alkylguanine-DNA alkyltransferase. It reacts in an autocatalytic and covalent manner with benzylguanine-modified substrates, providing a simple protein labelling system. SNAP-tag can be genetically fused with antibody fragments, creating fusion proteins that can be easily labelled with benzylguanine-modified payloads for site-directed delivery. This review aims to highlight the benefits and limitations of the abovementioned approaches and to outline how their combination could enhance photodynamic therapy for melanoma.

Abstract Chronic Lymphocytic Leukaemia (CLL) is a common B-lymphoid malignancy with over 200,000 people affected annually in Europe and the US. The aim of therapy is to increase the quality and duration of life using well tolerated treatment. Novel intracellular drug delivery systems such as functionalised nanoparticles (NPs), conjugated to antibodies such as anti-CD20 or anti-CD52 directed at cell surface markers may help address this need. We have explored the feasibility of targeting nanoparticles in CLL using a microfluidics based adhesion assay, anti CD52 cell targeting and Fludarabine therapy. Methods B cells were isolated from the peripheral blood of normal healthy donors and CLL patients. The CLL cell line, I-83, was maintained under standard conditions. Epifluorescent, laser scanning confocal and electron microscopy was utilised for imaging the interaction of metallic NPs with cells. The metallic NPs were polymer-coated for biocompatibility and cellular toxicity was assessed using flow cytometric analysis based on changes in light scattering. NPs distribution on the surface of the cells was visualized using epifluorescent and Helium ion microscopy, cellular uptake and alterations in cell morphology after NP treatment was imaged by confocal microscopy. Cell adhesion and migration behaviour under fluid shear flow conditions mimicking CLL cells in vivo was investigated using a microfluidics system utilising biochips coated with VCAM-1 and seeded with Human Umbilical Vein Endothelial Cells (HUVEC) or Human Dermal Lymphatic Endothelial Cells. CD52-Alexa Fluor® 633 was conjugated to the surface of silanized NPs (NP1) using standard carbo-diimide cross linker chemistry techniques and successful functionalisation of NPs was validated using flow cytometric analysis, monitoring a shift in fluorescent population. I-83 cells and patient-derived malignant B cells were treated using pH sensitive dye doped NPs and pH sensitive dye doped NP1 in order to assess interaction of nanoparticles with cells. Uptake measurements were performed through quantification of the fluorescence of the pH sensitive dye. As proof of concept, Fludarabine was then incorporated on to the surface of NPs in order to investigate its potential as a nanotherapeutic. Cytotoxicity studies were performed using flow cytometric analysis mentioned above following a 24 hour incubation. Results and Conclusions Quantitative and qualitative analysis identified uptake of NPs by normal and malignant B-lymphocytes with optimal NPs concentration for uptake determined at 25 μg/ml. Non-functionalised NPs in the range of 15-50nm were internalised by cells. There was a notable decrease in the interaction of NPs with cells under physiologically relevant fluid shear flow in comparison to static conditions, resulting in a corresponding decrease in uptake, highlighting the rationale for a CLL cell-targeted NP. The results of the adhesion experiment using I-83 cells and patient derived CLL cells to the HUVEC monolayer in a micro-fluidics system showed that patient CLL adhesion decreased after NP treatment (p=0.01, n=3). Cytotoxicity studies show that exposure to uncoated Fe2O3 nanoparticles yields an IC50 value of 23μg/mL +/- 5 μg/mL in comparison to coated, stabilized Fe2O3 nanoparticles with an IC50 of 49μg/mL +/- 5 μg/mL. Functionalisation of NPs with CD52 antibody (NP-1) resulted in significantly increased uptake (p<0.0001, n=3) and cytotoxicity. Preparation of these nanoparticles was reproducible and the particles remained stable in suspension for over 4 weeks. Cells treated with NPs bound Fludarabine were found to have significantly increased cytotoxicity in comparison to stabilized NPs (IC50 of 21μg/mL +/- 1μg/mL. In summary, this work provides proof of concept of efficacy for a targeted nanotherapeutic in haematological malignancies. Disclosures No relevant conflicts of interest to declare.