To combine cocktail chemotherapy and photodynamic therapy into one biocompatible and biodegradable nanocarrier, self-assembled DNA nanowires were fabricated and co-loaded with a photosensitizer chlorin e6 (Ce6) and a chemotherapeutic drug doxorubicin (DOX) for antitumor chemophotodynamic combination therapy. Two short DNA chains served as building blocks for the self-assembly of DNA nanowires in a supersandwich hybridization reaction that led to the successful formation of linear DNA nanowires of 500 bases, equal to a length of 167 nm. Ce6 and DOX were loaded onto the nanowires through covalent or noncovalent intercalation interactions, respectively. The DNA nanowires were taken up into cells, and the released Ce6 and DOX were ultimately distributed in different cellular compartments. The photosensitizer-loaded nanowires demonstrated increased generation of photodynamic reactive oxygen species (ROS) compared to that of free Ce6. In comparison with chemo- or photodynamic therapy alone, the combined treatment provided by DNA nanowires loaded with dual-drug significantly increased the incidence of HepG-2 cell death and produced a clear synergistic effect in the treatment of cancer cells. The DNA nanowire nanocarrier provided a flexible and quantitative drug-loading module that allowed for dose control of both drugs. More importantly, the DNA nanowires demonstrate a strong synergistic effect in antitumor chemophotodynamic combination therapy, likely because of increased photodynamic ROS generation and the distribution of Ce6 and DOX in different intracellular compartments. This work suggests that DNA nanowires may be useful as multifunctional and effective therapeutic nanocarriers for chemophotodynamic modalities in cancer therapy.

Nanoparticle fusion with cell membranes is an interesting phenomenon that may have crucial implications for their biomedical applications. Here, we proposed a biomimetic and controlled route to fusion of hydrophobic quantum dots (QDs) with the cell membranes of living cells, while preserving their sensing and optical properties and thus their capability of membrane imaging and single-nanoparticle tracking. Red blood cell (RBC) membrane lipids were extracted to phase transfer hydrophobic QDs and the resulting RBC-encapsulated QDs (RBC-QDs) can be well fused within cell membranes as membrane markers. The fusion was validated through single-nanoparticle imaging and different movement behaviours were reliably discriminated. RBC-QDs possessed some novel features, such as controllable selective membrane staining, no invasion, and high photobleaching resistance, which allowed for long-term imaging, and single-nanoparticle tracking. This approach provides a versatile platform for controlled hydrophobic QD-based fluorescence investigation of living cell membranes.

A DNA–protein hybrid hydrogel was constructed based on a programmable assembly approach, which served as a biomimetic physiologic matrix for efficient enzyme encapsulation. A dsDNA building block tailored with precise biotin residues was fabricated based on supersandwich hybridization, and then the addition of streptavidin triggered the formation of the DNA–protein hybrid hydrogel. The biocompatible hydrogel, which formed a flower-like porous structure that was 6.7 ± 2.1 μm in size, served as a reservoir system for enzyme encapsulation. Alcohol oxidase (AOx), which served as a representative enzyme, was encapsulated in the hybrid hydrogel using a synchronous assembly approach. The enzyme-encapsulated hydrogel was utilized to extend the duration time for ethanol removal in serum plasma and the enzyme retained 78% activity after incubation with human serum for 24 h. The DNA–protein hybrid hydrogel can mediate the intact immobilization on a streptavidin-modified and positively charged substrate, which is very beneficial to solid-phase biosensing applications. The hydrogel-encapsulated enzyme exhibited improved stability in the presence of various denaturants. For example, the encapsulated enzyme retained 60% activity after incubation at 55 °C for 30 min. The encapsulated enzyme also retains its total activity after five freeze–thaw cycles and even suspended in solution containing organic solvents.

•A general and facile strategy for preparing metal sulfide nanocrystals was reported based on metallurgical leaching of metal powders.•In2S3, Ag2S, and AgInS2 nanocrystals can be synthesized just mixture of Ag, In, and dithiocarbamate in stoichiometric molar ratio.•The size, shape, and chemical composition of the nanomaterials can be easily controlled, and the metal sulfides exhibit novel optical properties.We report the synthesis of high-quality metal sulfide semiconductor nanocrystals through a facile and general metallurgical processes. Metal powders employed as readily available chemicals were metallurgically leached with dithiocarbamate in chloroform solution to form in situ the metal dithiocarbamate complex precursor, which was directly heated under appropriate experimental conditions to produce a variety of metal sulfide nanocrystals. Based on this, 11.8, and 21.5 nm uniform spherical Ag2S and 34.5 nm cubic Ag2S nanocrystals were synthesized. Binary In2S3 nanocrystals with 9.1 nm were obtained from the reaction of indium and dithiocarbamate. Furthermore, ternary AgInS2 nanocrystals were prepared from a reaction mixture of Ag, In, and dithiocarbamate in stoichiometric molar ratio. Using this method, the size, shape, and chemical composition of the nanomaterials can be easily controlled, and these as-synthesized metal sulfides exhibit novel optical properties. This facile methodology for the synthesis of metal sulfides can be generally expanded to fabricate other nanocrystals, and the readily available metal elements may provide an alternative approach for the industrial synthesis of nanomaterials.

•Surface phenylboronic acid functionalized mesoporous silica sphere was developed as a biomimetic compartment.•The permeation into the biomimetic compartment can be gated by dopamine in the solution.•The presence of dopamine reversed the surface charge of the biomimetic compartment.The building of artificial systems with similar structure and function as cellular compartments will expand our understanding of compartmentalization related biological process and facilitate the construction of biomimetic highly functional structures. Herein, surface phenylboronic acid functionalized mesoporous silica sphere was developed as a biomimetic dopamine gated compartment, in which the ionic permeability can be well modulated through the dopamine-binding induced charge reversal. As the phenylboronic acid is negatively charged, the negatively charged 1, 3, 6, 8-pyrenetetrasulfonic acid (TPSA) was hindered from permeation into the biomimetic compartment. However, the presence of dopamine and its binding with phenylboronic acid reversed the gatekeeper shell from negative to positive charged and gated the permeation of TPSA into the interior. The dopamine gated permeation phenomenon resembles that in biological system, and thus the phenylboronic acid functionalized mesoporous silica sphere was taken as a simple model for dopamine gated ion channel decorated biological compartment. It will also contribute to the development of artificial cell and responsive nanoreactor.A biomimetic dopamine gated compartment was constructed with surface phenylboronic acid functionalized mesoporous silica sphere.

Nanoparticle fusion with cell membranes is an interesting phenomenon that may have crucial implications for their biomedical applications. Here, we proposed a biomimetic and controlled route to fusion of hydrophobic quantum dots (QDs) with the cell membranes of living cells, while preserving their sensing and optical properties and thus their capability of membrane imaging and single-nanoparticle tracking. Red blood cell (RBC) membrane lipids were extracted to phase transfer hydrophobic QDs and the resulting RBC-encapsulated QDs (RBC-QDs) can be well fused within cell membranes as membrane markers. The fusion was validated through single-nanoparticle imaging and different movement behaviours were reliably discriminated. RBC-QDs possessed some novel features, such as controllable selective membrane staining, no invasion, and high photobleaching resistance, which allowed for long-term imaging, and single-nanoparticle tracking. This approach provides a versatile platform for controlled hydrophobic QD-based fluorescence investigation of living cell membranes.