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Role of Engineered Proteins as Therapeutic Formulations
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Khushboo Gulati, Krishna Mohan Poluri
Z-doamin affibody specific to Taq DNA polymerase was generated through a combinatorial library of three-helix bundle. To further increase the affinity of affibody, a hierarchical library was generated by stochastic evaluation of 6 amino acids in one of helices that bind to Taq DNA polymerase. Affibody with a binding affinity of 30–50 nM was obtained for Taq DNA polymerase (Gunneriusson et al., 1999). Affibodies particular to proteins that are highly specific for different types of cancers are being developed to detect different malignancies. Affibody specific to HER2 has been engineered that showed binding affinity of 22 pmol/L to HER2 and hence can be used to detect the expression of HER2 in the cells using gamma camera (Orlova et al., 2006). Fluorescently labeled affibodies are being produced to function as biosensors. The triple-labeled affibody molecule has already been shown to detect unlabeled human IgG and IgA (Engfeldt et al., 2005). Affibody molecules are also being exploited in numerous biotechnological, pharmaceutical, and diagnostic applications which are discussed in detail in a review by Löfblom et al. and Nygren (Nygren, 2008; Lofblom et al., 2010).
Nanobubbles: State of the Art, Features, and the Future
Published in Vladimir Torchilin, Handbook of Materials for Nanomedicine, 2020
Monica Argenziano, Federica Bessone, Roberta Cavalli
Affibody molecules are a type of engineered ultrasmall protein with low molecular weight, high affinity, and specificity. These molecules conjugated to various nanoparticles have been evaluated for different purposes, such as targeted drug delivery and molecular imaging [60].
Application of nanoparticles in cancer detection by Raman scattering based techniques
Published in Nano Reviews & Experiments, 2018
Rouhallah Ravanshad, Ayoob Karimi Zadeh, Ali Mohammad Amani, Seyyed Mojtaba Mousavi, Seyyed Alireza Hashemi, Amir Savar Dashtaki, Esmail Mirzaei, Bijan Zare
New investigations have demonstrated that up to five spectral signatures can be recognized and spectrally separated simultaneously in living subjects. Hence, a specific signature that is associated with a specific targeting ligand of the molecular profile of the cancer (i.e. a peptide, monoclonal antibody, affibody, or aptamer) which is coupled to the nanoparticle, can be determined by spectrally separating the SERS signatures in the detected signals from a tumor [32]. The SERS technique has excellent selectivity, rapid detection capability, high signal-to-noise ratio, non-photo bleaching features, and the use of single photo-excitation [20]. Another way to obtain larger Raman scattering enhancements, which is in close relationship with SERS, is to put the target molecule in the fractal space between aggregated colloidal nanoparticles, known as ‘hot spots’ [33–36]. Additionally, we can exploit SERS not only for detection of known biomarkers, but also to detect novel and potential cancer biomarkers. However, a major weakness of this technique is the lack of reliable SERS substrates. Currently available substrates usually contain irregular active sites that suffer from strong spatial and temporal fluctuation in Raman intensity, and thus do not produce stable Raman output [29]. Still, there are a few sample pretreatment methods, such as Western blot SERS, fluorescein isothiocyanate-linked SERS, and ligand SERS, that can increase the sensitivity of SERS detection [22,37].
Recent advances on fluorescent biomarkers of near-infrared quantum dots for in vitro and in vivo imaging
Published in Science and Technology of Advanced Materials, 2019
Shanmugavel Chinnathambi, Naoto Shirahata
Qin et al. synthesized fluorescence-CT dual-mode nanoprobe by making use of DSPE-PEG2000-FA and other amphiphilic molecules to coat Ag2S QDs and iodinated oil simultaneously. In vivo experiments revealed that the probe has a rather long circulation time (blood half-life of 5.7 h), and the histopathological tissue tests indicated that it is not damaging to essential organs normal function [63]. Gui at al. demonstrated a facile aqueous synthesis of Ag2SQDs (2.6–3.7 nm) with bright and tunable PL emission in a broad range from the red to NIR-II (λem = 687 to 1096 nm), employing multidentate polymers as capping reagents [64]. Duman et al. established the aqueous synthesis of cationic, NIR-emitting Ag2S QDs (λem = 810–840 nm) with a mixed coating of MPA and Polyethylenimine (25 kDa) as new theranostic agent [65,66]. Shi et al. prepared high-quality, NIR-emitting Ag2Se QDs with distinct absorption features and high PL QYs using ODE–Se as the Se precursor [67]. Theodorou et al. demonstrated significant enhancement of PL intensity in the NIR-II region for Ag2S QDs, using Au nanostructures produced by colloidal lithography [68]. Zhang et al. effectively modified Ag2S QDs with a tumor-targeting small protein, affibody ZEGFR: 1907, via charge interaction. The resulting probe displays an EGFR targeted tumor imaging property, and it has a high potential for bio-imaging [69]. In 2014, Chen et al. prepared Ag2S QDs conjugated with TAT peptide in the second NIR window (NIR-II, 1.0–1.4 μm) for dynamically tracking of human mesenchymal stem cells in vivo with high sensitivity and high spatial and temporal resolution [70]. Recently, Chen et al. reviewed and discussed tracking the transplanted stem cells using fluorescent nanoprobes in the first and second biological window [71].