DNA has proven of high utility to modulate the surface functionality of metal–organic frameworks (MOFs) for various biomedical applications. Nevertheless, current methods for preparing DNA–MOF nanoparticles rely on either inefficient covalent conjugation or specific modification of oligonucleotides. In this work, we report that unmodified oligonucleotides can be loaded on MOFs with high density (∼2500 strands/particle) via intrinsic, multivalent coordination between DNA backbone phosphate and unsaturated zirconium sites on MOFs. More significantly, surface-bound DNA can be efficiently released in either bulk solution or specific organelles in live cells when free phosphate ions are present. As a proof-of-concept for using this novel type of DNA–MOFs in immunotherapy, we prepared a construct of immunostimulatory DNA–MOFs (isMOFs) by intrinsically coordinating cytosine–phosphate–guanosine (CpG) oligonucleotides on biocompatible zirconium MOF nanoparticles, which was further armed by a protection shell of calcium phosphate (CaP) exoskeleton. We demonstrated that isMOFs exhibited high cellular uptake, organelle specificity, and spatiotemporal control of Toll-like receptors (TLR)-triggered immune responses. When isMOF reached endolysosomes via microtubule-mediated trafficking, the CaP exoskeleton dissolved in the acidic environment and in situ generated free phosphate ions. As a result, CpG was released from isMOFs and stimulated potent immunostimulation in living macrophage cells. Compared with naked CpG–MOF, isMOFs exhibited 83-fold up-regulation in stimulated secretion of cytokines. We thus expect this isMOF design with soluble CaP exoskeleton and an embedded sequential “protect–release” program provides a highly generic approach for intracellular delivery of therapeutic nucleic acids.

Introduction of exogenous biomacromolecules into living systems is of great interest in genome editing, cancer immunotherapy, and stem cell reprogramming. Whereas current strategies generally depend on nucleic acids transfection, direct delivery of functional proteins that provides enhanced specificity, increased safety, and fast and temporal regulation is highly desirable. Nevertheless, intracellular delivery of intact and bioactive proteins, especially in vivo, remains poorly explored. In this study, we developed a nanodiamonds (NDs)-based protein delivery system in cultured cells and in Drosophila that showed high adsorption, high efficiency, and effective cytosolic release of fully functional proteins. Through live-cell imaging, we observed a novel phenomenon wherein a substantial amount of internalized NDs–protein complex rejected fusion with the early endosome, thereby evading protein degradation in the lysosome. More significantly, we demonstrated that dietary NDs–RNase induced apoptosis in enterocytes, stimulating regenerative divisions in intestinal stem cells and increasing the number of stem cells and precursor cells in Drosophila intestine. As stem cells are poorly accessible by exogenous agents in vivo, NDs-mediated oral delivery of proteins provides a new approach to modulate the stem cell microenvironment for intestinal remodeling, which has important implications for colorectal cancer therapy and regenerative medicine.Keywords: intestinal remodeling; nanodiamonds; oral delivery; protein delivery; stem cells microenvironment;

Nanoparticles (NPs) have shown great promise as intracellular imaging probes or nanocarriers and are increasingly being used in biomedical applications. A detailed understanding of how NPs get “in and out” of cells is important for developing new nanomaterials with improved selectivity and less cytotoxicity. Both physical and chemical characteristics have been proven to regulate the cellular uptake of NPs. However, the exocytosis process and its regulation are less explored. Herein, we investigated the size-regulated endocytosis and exocytosis of carboxylated polystyrene (PS) NPs. PS NPs with a smaller size were endocytosed mainly through the clathrin-dependent pathway, whereas PS NPs with a larger size preferred caveolae-mediated endocytosis. Furthermore, our results revealed exocytosis of larger PS NPs and tracked the dynamic process at the single-particle level. These results indicate that particle size is a key factor for the regulation of intracellular trafficking of NPs and provide new insight into the development of more effective cellular nanocarriers.Keywords: endocytosis; exocytosis; imaging; intracellular trafficking; nanoparticles;

•A smartphone interfaced electrochemical chip device for the on-site gender verification was developed.•The two enzymes joint detection ensured the clear discrimination of male and female group.•This device retained well when we used the device in serum and serum stains.•The whole detection can be completed within 20 min.•The portability of smartphone based device is well suitable in the applications such as on-site analysis.On-site detection of biomarkers in biofluids found at the crime scene is critically important forensic analysis. However, it remains difficult due to the lack of portable, fast and cheap on-site analytical devices. Traditional methods including polymerase chain reaction (PCR) and electrophoresis requires complicated instrumentation and critical environment. Optical analytical methods can be affected by intrinsic adsorption of complicated sample such as serum. In response, we developed a smartphone-interfaced electrochemical chip device for on-site gender verification. The detection is based on the known difference of biomarkers (creatine kinase (CK) and alanine transaminase (ALT)) between male and female groups. Enzyme cascade reaction converted the enzyme level in biofluids to the consumption of NADH, which can be electrochemically detected by our designed electrochemical chip. Our device retained the capability of gender verification when used in serum and serum stains. The detection can be completed in 20 min. Gender verification of real samples (39 serum samples) demonstrated excellent sensitivity and specificity of this smartphone based device.

Autophagy is a basic cellular process that decomposes damaged organelles and aberrant proteins. Dysregulation of autophagy is implicated in pathogenesis of neurodegenerative disorders, including Parkinson’s disease (PD). Pharmacological compounds that stimulate autophagy can provide neuroprotection in models of PD. Nanoparticles have emerged as regulators of autophagy and have been tested in adjuvant therapy for diseases. In this present study, we explore the effects of quantum dots (QDs) that can induce autophagy in a cellular model of Parkinson’s disease. CdTe/CdS/ZnS QDs protect differentiated rat pheochromocytoma PC12 cells from MPP+-induced cell damage, including reduced viability, apoptosis and accumulation of α-Synuclein, a characteristic protein of PD. The protective function of QDs is autophagy-dependent. In addition, we investigate the interaction between quantum dots and autophagic pathways and identify beclin1 as an essential factor for QDs-induced autophagy. Our results reveal new promise of QDs in the theranostic of neurodegenerative diseases.

Graphene oxide (GO) has attracted more and more attention as a promising nanomaterial in biomedical research and applications. In this study, we explore the ability of GO as nanocarrier for synthetic DNA strands. Immunostimulatory CpG oligodeoxynucleotides (ODNs) are attached to Poly-l-Lysine (PLL) functionalized, polydisperse GO, or uniform small GO (sGO) nanosheets. Both types of GO-CpG ODN nanoconjugates can be delivered into murine Raw264.7 macrophages and possess immunostimulatory activity, while sGO-CpG appears to be a more efficient stimulator. In addition, sGO-CpG nanosheets exhibit higher cellular uptake but better biocompatibility compared to the larger GO-CpG counterpart. Furthermore, PLL functionalized sGO-CpG has higher immunostimulatory activity than azide functionalized sGO-CpG. Together, our studies provide evidence that sGO can be utilized as an ideal intracellular nanocarrier for synthetic single-stranded DNA, and sGO-PLL-CpG conjugates may serve as a potential proinflammatory therapeutic tool.Keywords: CpG ODN; graphene oxide; immunostimulatory activity; nanocarrier; uniform small;