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Simple and effective detection methods for circulating tumor cells are essential for early detection and progression monitoring of tumors. The use of DNA aptamer and bioluminescence is expected to be a key tool for the simple, effective, and sensitive detection of tumor cells. Herein, we designed multifunctional protein nanoparticles for the detection of tumor cells using DNA aptamer and bioluminescence. Fusion proteins (ELP-poly(d)-POIs), composed of elastin-like polypeptide (ELP) fused with protein of interests (POIs) via poly(aspartic acid) (poly(d)), formed the protein nanoparticles based on the temperature responsivity of ELP sequences, leading to multiply displayed POIs on the protein nanoparticles. In the present study, we focused on porcine circovirus type 2 replication initiation protein (Rep), which covalently conjugated with DNA aptamers, and NanoLuc luciferase (Nluc), which emitted a strong bioluminescence, as POIs. ELP-poly(d)-Rep and ELP-poly(d)-Nluc were constructed and formed the protein nanoparticles with multiply displayed Nluc and Rep (DNA aptamer) that amplified the bioluminescence signal and tumor recognition ability. Mucin-1 (MUC1)-overexpressing human breast tumor MCF7 cells and MUC1-recognizing aptamer (MUC1 aptamer) were selected as models. The MUC1 aptamer-conjugated protein nanoparticles exhibited a 13.7-fold higher bioluminescence signal to MCF-7 cells than to human embryonic kidney 293 (HEK293) cells, which express low levels of MUC1. Furthermore, the protein nanoparticles could detect up to 70.7 cells/mL of MCF-7 cells from a cell suspension containing HEK-293. The protein nanoparticles with multiple Rep and Nluc show a great potential as a material for detecting CTCs.

Detection of small amounts of target molecules with high sensitivity is important for the diagnosis of many diseases, including cancers, and is particularly important to detect early stages of disease. Here, we report the development of a temperature-responsive fusion protein (ELP-DCN) comprised of an elastin-like polypeptide (ELP), poly-aspartic acid (D), antibody-binding domain C (C), and NanoLuc luciferase (N). ELP-DCN proteins form nanoparticles above a certain threshold temperature that display an antibody-binding domain and NanoLuc luciferase on their surface. ELP-DCN nanoparticles can be applied for enhancement of immunoassay systems because they provide more antibody-binding sites and an increased number of luciferase molecules, resulting in an increase in assay signal. Here, we report the detection of human serum albumin (HSA) as a model protein using anti-HSA and ELP-DCN proteins. Upon formation of ELP-DCN nanoparticles, the detection limit improved tenfold compared to the monomeric form of ELP-DCN., (© 2022. Springer-Verlag GmbH Germany, part of Springer Nature.)

Photoactive artificial nanocatalysts that mimic natural photoenergy systems can yield clean and renewable energy. However, their poor photoabsorption capability and disfavored photogenic electron–hole recombination hinder their production. Herein, we designed two nanocatalysts with various microstructures by combining the tailored self-assembly of the meso-tetra(p-hydroxyphenyl) porphine photosensitizer with the growth of titanium dioxide (TiO2). The porphyrin photoabsorption antenna efficiently extended the absorption range of TiO2 in the visible region, while anatase TiO2 promoted the efficient electron–hole separation of porphyrin. The photo-induced electrons were transferred to the surface of the Pt co-catalyst for the generation of hydrogen via water splitting, and the hole was utilized for the decomposition of methyl orange dye. The hybrid structure showed greatly increased photocatalytic performance compared to the core@shell structure due to massive active sites and increased photo-generated electron output. This controlled assembly regulation provides a new approach for the fabrication of advanced, structure-dependent photocatalysts. [ABSTRACT FROM AUTHOR]