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In this work, AgNPs and Van molecules were modified on the surface of LDH sheets via the reduction of Ag ions with glucose and the adsorption of Van. The products were characterized by high resolution transmission electron microscopy ( HRTEM ), energy dispersive spectroscopy ( EDS ) and Fourier-transform ( FT-IR ) spectroscopy . The results demonstrated that a homogeneous distribution of AgNPs of 30 nm in size as well as Van molecules were attached onto the surface of the LDH sheets. Owing to their properties, they were demonstrated to be quite efficient for the simultaneous capture and disinfection of bacteria, and showed much higher bacteria disinfection properties to Escherichia coli ( E. coli ) and Staphyloccocus aureus ( S. aureus ) compared to Ag/LDH, Van/LDH and LDHs due to the combined effect of Ag and vancomycin . The prepared Van–Ag/LDHs effectively combined Van and AgNPs together using LDH sheets, overcoming the disadvantages of Van in that it only shows disinfection properties towards Gram-positive bacteria, and those of AgNPs in that they have low dispersity and stability, which may have wide applications in the field of sterilization.

An electrochemical sensor using a novel three dimensional (3D) ternary Pt nanodendrite/reduced graphene oxide/MnO 2 nanoflower (Pt/RGO/MnO 2 ) modified glassy carbon electrode was proposed for the selective and sensitive determination of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to evaluate electrochemical behaviors of DA on the as-prepared electrode. The oxidation peak current of DA is linearly proportional to its concentration in the range from 1.5–215.56 μM, with a detection limit of 0.1 μM (at S/N = 3). Compared to bare RGO, Pt nanodendrite/RGO and MnO 2 nanoflower modified electrodes, the 3D hierarchical ternary Pt/RGO/MnO 2 composites displayed the highest electrocatalytic activity for the selective detection of DA. Moreover, the 3D Pt/RGO/MnO 2 modified electrode can be reused with no obvious deterioration in the electrocatalytic performance. This work paves the way for developing a novel 3D nanostructure and offers new opportunities for improving the performance of electrochemical sensors with excellent sensitivity, repeatability and anti-interference.

Using nanotechnology, therapeutics can be combined with diagnostics for cancer treatment. To do this, a targeting ligand, an imaging contrast agent and an anti-tumour therapeutic agent were the minimum requirements for active targeting nanoassemblies. Here we have developed a novel active targeting theranostic agent, made up of just two components, aptamer AS1411 and graphene quantum dots (GQDs). Each component in our agent plays multiple roles. Confocal microscopy using a 488 nm laser shows that this agent has an excellent capability to label tumour cells selectively. On the therapeutic side, this agent induced a synergistic growth inhibition effect towards cancer cells when irradiated with a near infrared laser of 808 nm. The ultra-small size, good biocompatibility, intrinsic stable fluorescence, and near-infrared response character make GQDs a remarkable constituent to build theranostic agents.

A new two-photon fluorescent probe ( MCN ) for viscosity imaging was developed based on a 6-substituted quinoline framework. MCN showed an excellent “off–on” fluorescence response ( ca. 90-fold enhancement) with viscosity increasing in the glycerol–water viscosity system. MCN showed great sensitivity to viscosity ( R 2 = 0.98, x = 0.65), which gave rise to cell imaging for micro-viscosity or real-time cell imaging during apoptosis with low cytotoxicity under two-photon excitation ( λ ex = 800 nm). Fluorescence lifetime imaging (FLIM) of living HeLa cells stained with MCN revealed that the intracellular average viscosity value was 73.45 ± 21.55 cP in cytosol. Imaging in living tissue slices indicated that MCN can work in deep tissue (～130 μM) under two-photon excitation. Moreover, MCN also showed the capacity for in vivo imaging viscosity in zebrafish with obvious fluorescence emission.

A light-activated cleavage strategy for the concomitant release of active drugs and generation of fluorescence changes is highly desirable. Herein a molecular prodrug featuring real-time monitoring of drug localization and release by manipulating fluorophores has been created by constructing a cleavable structure which comprises a photoremovable coumarinyl, an anticancer drug camptothecin, a cleavable linker and a near infrared fluorescent dye dicyanomethylene-4 H -pyran ( DCM ). The fluorescence of coumarinyl and CPT is completely quenched by the DCM moiety via fluorescence resonance energy transfer (FRET). The internalization of the prodrug by cells and its subsequent intracellular location can be tracked by collecting the red fluorescence of DCM ; while the release of active CPT as a result of one- or two-photon irradiation can be monitored by observing the newly emerged fluorescence of CPT under one- or two-photon excitation. The prodrug also shows highly controllable cytotoxicity toward HeLa cells and A549 cells, with low IC 50 values of 4.01 and 2.53 μM, respectively, upon light irradiation and with much higher IC 50 values ( 40 μM) without light irradiation. This strategy may provide an approach for the development of light-activatable theranostic anticancer therapeutics.

Small interference RNA (siRNA) has demonstrated unprecedented potential as a therapy for drug-resistant cancer. However, efficient cellular delivery is still a challenge due to hydrolytic sensitivity and poor cellular uptake of siRNA. Strategies to conjugate siRNA to the delivery vehicle and activate innate immunity have shown low in vivo efficacy. Therefore, nanomedicine approaches have become the main focus in this field. B-cell lymphoma 2 (Bcl-2) is the founding member of the Bcl-2 family of regulatory proteins that regulate cell death (apoptosis), by either inducing (pro-apoptotic) or inhibiting (anti-apoptotic) apoptosis. In this report, a nanomedicine system is constructed using Bcl-2 siRNA as the therapeutic agent and mesoporous polymer nanosphere (MPN) carriers to both improve cellular internalization and achieve Bcl-2 silencing and cell apoptosis. MPNs were prepared through a two-stage hydrothermal process at two different temperatures, which was deliberately designed to form nanospheres via self-assembly and create mesoporous structures by removing the pore-forming templates. Such MPNs were proved to be biodegradable. Without any carbonization process, MPNs still keep many active groups which endow them with excellent properties for functionalization purposes. Finally, the FA-targeted-Bcl-2-siRNA-loaded nanoparticles were constructed by a layer-by-layer assembly by electrostatic interactions after nitrification. These nanoparticles were efficiently delivered into breast cancer (BC) cells, showing a significant sequence-specific inhibition of Bcl-2 mRNA expression in BC cells, enhanced tumor cell apoptosis and tumor therapeutic efficacy. Taken together, this study establishes a novel therapeutic system for cancer therapy.

Mechanically strong hydrogel–HAp composites have been successfully fabricated through in situ formation of hydroxyapatite (HAp) in a tough polyacrylamide (PAAm) hydrogel with a modified electrophoretic mineralization method. The pre-swelling of the PAAm hydrogels in CaCl 2 buffer solutions makes the electrophoresis method able to produce large area (10 × 8 cm 2 ) hydrogel–HAp composites. At the same time the CaCl 2 solution with different concentrations could control the HAp contents. The obtained hydrogel–HAp composites exhibit enhanced mechanical properties, namely higher extensibility ( 2000%), tensile strength (0.1–1.0 MPa) and compressive strength (up to 35 MPa), in comparison to the as-synthesized PAAm hydrogels. FTIR and Raman characterizations indicate the formation of strong interactions between PAAm chains and HAp particles, which are thought to be the main reason for the enhanced mechanical properties. The hydrogel–HAp composite also shows excellent osteoblast cell adhesion properties. These composite materials may find more applications in biomedical areas, e.g. as a matrix for tissue repair especially for orthopedic applications and bone tissue engineering.

To improve the biocompatibility and biodegradability of nanocarriers, well-defined poly(vinylcaprolactam)-based acid degradable nanogels were fabricated for drug delivery via precipitation polymerization in water, where synthetic ketal-based 2,2-dimethacroyloxy-1-ethoxypropane (DMAEP) acted as a cross-linker, and N -(2-hydroxypropyl)methacrylamide (HPMA) served as a co-monomer. Expectedly, we observed that the temperature and pH of the environment play important roles in the performance of the nanogels. The nanogels were reduced in size upon increasing the temperature and showed higher volume phase transition temperature (VPTT) with higher concentration of HPMA. With the incorporation of ketal linkages, the nanogels showed accelerated degradation profiles by lowering the pH and increasing temperature of the incubation medium. When used as nanocarriers of anticancer drug doxorubicin (DOX), compared to non-degradable nanogels with similar components, the acid-degradable nanogels displayed more effective drug controlled release behaviour, low drug leakage of DOX at neutral pH while rapid and sufficient release from the nanogels under acidic conditions. The results of the cytotoxicity and hemolysis assays further highlighted that the acid-degradable nanogel produced no hemolysin but showed excellent viability to normal cells, and the DOX-loaded nanogel exhibited higher proliferation inhibition against tumor cells.

Although photothermal therapy (PT) and photothermal-chemotherapy (PT-CT) treatments have been used to achieve complete ablation of solid tumors, they are often implemented at more than 50 °C under high intensity and using a high dose of NIR irradiation, concomitantly inducing heavy skin burning, tissue damage, and ugly scarring. Moreover, the residual tumor cells at the treated site cannot be completely eradicated, resulting in tumor recurrence and metathesis. These key obstacles have prohibited PT and PT-CT treatments from transitioning to clinical use, therefore achieving traceless ablation of solid tumors without recurrence is still a challenge for real applications. To balance hyperthermia and a high drug-loading capacity in polyprodrugs to achieve mild PT-CT, we rationally designed a novel type of intracellular pH and reduction-cleavable chlorambucil prodrug and synthesized high drug-loading polydopamine-chlorambucil conjugate nanoparticles (PDCBs). The PDCBs show good photothermal properties and demonstrate intracellular pH-, reduction-cleavable, and external near infrared (NIR)-triggered drug release profiles. Polydopamine-chlorambucil conjugate nanoparticles with 40 wt% CB (PDCB 40 ) and mild NIR irradiation could facilitate cellular internalization and subcellular trafficking, generating an excellent and synergistic antitumor effect in vitro . Pharmacokinetics and small animal fluorescent and photoacoustic imaging demonstrate that PDCB 40 has a 3.6-fold longer blood circulation time compared to free CB and attained selective tumor accumulation, simultaneously inducing a 4.1-fold stronger photoacoustic signal than the control. By using one intravenous injection of PDCB 40 and a single dose of mild NIR irradiation, this simple and mild PT-CT treatment achieved a non-discerned tumor on the sixth day, and traceless and complete ablation of a solid MCF-7 tumor without recurrence within 50 days, opening up a new avenue for precise cancer therapy with the potential for real applications.

Angiogenesis represents a major focus for novel therapeutic approaches to the treatment and management of multiple pathological conditions, such as ischemic heart disease and critical-sized bone defect. The complex process of angiogenesis begins when cells within a tissue respond to hypoxia by increasing their production of vascular endothelial growth factor (VEGF). Loading biomaterials with angiogenic therapeutics have emerged as a promising approach for developing superior biomaterials for tissue repair and regeneration due to the possibility of reducing treatment costs and side effects when compared to the use of growth factors or genetic engineering approaches. Trace elements, such as copper (Cu), have been reported to be capable of inhibiting prolyl hydroxylases leading to the accumulation and activation of hypoxia-inducible factor-1α (HIF-1α), a major transcription factor regulating the expression of VEGF. It has also recently been speculated that the artifically induced hypoxic microenvironment may regulate the local immune response, which in turn, further facilitates the tissue repair process. The present study has incorporated ionic Cu 2+ into mesoporous bioactive glass (MBG), a promising bioactive material system for regenerative medicine, and investigated its effect on angiogenesis and immune responses both in vitro and in vivo . Our results demonstrated that hypoxia-mimicking materials could induce VEGF secretion of bone marrow-derived mesenchymal stromal cells (BMSCs), which provided a positive feedback loop for early blood vessel formation by stimulating migration and tube formation of human umbilical vein endothelial cells (HUVECs). Furthermore, a tissue-regenerative macrophage subtype was triggered by Cu-MBG, leading to superior angiogenic responses (tube formation and angiogenic gene expression) compared to the traditional MBG material. It is concluded that the addition of inorganic ions leads to enhanced angiogenesis and immune responses, which holds promise for the development of functional tissue-engineered constructs to repair and regenerate damaged tissues and organs.