Photoinduced Rapid Transformation from Au Nanoagglomerates to Drug-Conjugated Au Nanovesicles

Smart paper transformer: new insight for enhanced catalytic efficiency and reusability of noble metal nanocatalysts

Although noble metal nanocatalysts show superior performance to conventional catalysts, they can be problematic when balancing catalytic efficiency and reusability. In order to address this dilemma, we developed a smart paper transformer (s-PAT) to support nanocatalysts, based on easy phase conversion between paper and pulp, for the first time. The pulp phase was used to maintain the high catalytic efficiency of the nanocatalysts and the transformation to paper enabled their high reusability. Herein, as an example of smart paper transformers, a novel chromatography paper-supported Au nanosponge (AuNS/pulp) catalyst was developed through a simple water-based preparation process for the successful reduction of p-nitrophenol to demonstrate the high catalytic efficiency and reusability of the noble metal nanocatalyst/pulp system. The composition, structure, and morphology of the AuNS/pulp catalyst were characterized by XRD, TGA, FE-SEM, ICP, TEM, FT-IR, and XPS. The AuNS/pulp catalyst was transformed into the pulp phase during the catalytic reaction and into the paper phase to recover the catalysts after use. Owing to this smart switching of physical morphology, the AuNS/pulp catalyst was dispersed more evenly in the solution. Therefore, it exhibited excellent catalytic performance for p-nitrophenol reduction. Under optimal conditions, the conversion rate of p-nitrophenol reached nearly 100% within 6 min and the k value of AuNS/pulp (0.0106 s⁻¹) was more than twice that of a traditional chromatography paper-based catalyst (0.0048 s⁻¹). Additionally, it exhibited outstanding reusability and could maintain its high catalytic efficiency even after fifteen recycling runs. Accordingly, the unique phase switching of this smart paper transformer enables Au nanosponge to transform into a highly efficient and cost-effective multifunctional catalyst. The paper transformer can support various nanocatalysts for a wide range of applications, thus providing a new insight into maintaining both high catalytic efficiency and reusability of nanocatalysts in the fields of environmental catalysis and nanomaterials.

A smart paper transformer supported nanocatalyst platform is developed based on the facile phase conversion between paper and pulp for both high-efficiency and high-reusability catalysis, with wide applications demonstrated by using Au nanosponge.

Multi-responsive albumin-lonidamine conjugated hybridized gold nanoparticle as a combined photothermal-chemotherapy for synergistic tumor ablation

Herein, we developed a multifunctional nanoplatform based on the nanoassembly of gold nanoparticles (GNP) conjugated with lonidamine (LND) and aptamer AS1411 (AS-LAGN) as an effective cancer treatment. Conjugating AS1411 aptamer on the surface of the nanoparticle significantly improved particle accumulation in cancer cells via specific affinity toward the nucleolin receptors. In vitro study clearly revealed that laser irradiation-based hyperthermia effect enhanced the chemotherapeutic effects of LND. Combinational treatment modalities revealed significant apoptosis with higher cell killing effect due to increased ROS production and inhibition of cell migration. GNP's ability to convert the excited state photon energy into thermal heat enabled synergistic photothermal/chemotherapy with improved therapeutic efficacy in animal models. Moreover, immunohistochemistry staining assays confirmed the ability of AS-LAGN to induce cellular apoptosis/necrosis and ablation in tumor tissues, without causing evident damages to the surrounding healthy tissues. Altogether, this AS-LAGN nanoplatform could be a promising strategy for mitochondria-based cancer treatment. STATEMENT OF SIGNIFICANCE: We have designed a facile biodegradable multifunctional nanocarrier system to target the mitochondria, the major "power house" of the cancer cells. We have constructed a multifunctional nanoassembly of protein coronated gold nanoparticles (GNP) conjugated with lonidamine (LND) and aptamer AS1411 (AS-LAGN) as an effective combination of phototherapy with chemotherapy for cancer treatment. The LND was conjugated with albumin which was in turn conjugated to GNP via redox-liable disulfide linkage to generate oxidative stress and ROS to kill cancer cells. GNP's ability to convert the excited state photon energy into thermal heat enabled synergistic photothermal/chemotherapy with improved therapeutic efficacy in animal models. Consistently, AS-LAGN showed enhanced antitumor efficacy in xenograft tumor model with remarkable tumor regression property.

Development of Folate-Functionalized PEGylated Zein Nanoparticles for Ligand-Directed Delivery of Paclitaxel

In this study, we investigated the active targeted delivery of a hydrophobic drug, paclitaxel (PTX), via receptor-mediated endocytosis by folate receptors expressed on cancer cells using a protein-based nanoparticle system. PTX was loaded on zein nanoparticles and conjugated with folate (PTX/Zein-FA) to estimate its chemotherapeutic efficacy in folate receptor-expressing KB cancer cells. PTX/Zein-FA nanoparticles were successfully developed, with a nanoparticle size of ~180 nm and narrow polydispersity index (~0.22). Accelerated release of PTX in an acidic environment was observed for PTX/Zein-FA. An in vitro cellular study of PTX/Zein-FAs in KB cells suggested that PTX/Zein-FA improved the cytotoxic activity of PTX on folate receptors overexpressed in cancer cells by inducing proapoptotic proteins and inhibiting anti-apoptotic proteins. In addition, PTX/Zein-FA exhibited anti-migratory properties and could alter the cell cycle profile of KB cells. A549 cells, which are folate receptor-negative cancer cells, showed no significant enhancement in the in vitro cellular activities of PTX/Zein-FA. We describe the antitumor efficacy of PTX/Zein-FA in KB tumor-bearing mice with minimum toxicity in healthy organs, and the results were confirmed in comparison with free drug and non-targeted nanoparticles.

Multifunctional Albumin-Based Delivery System Generated by Programmed Assembly for Tumor-Targeted Multimodal Therapy and Imaging

To enhance the treatment efficiency in tumor therapy, we developed a tumor-targeting protein-based delivery system, DOX&ICG@BSA-KALA/Apt, to efficiently integrate multimodal therapy with tumor imaging and realize synchronous photodynamic therapy/photothermal therapy/chemotherapy. In the delivery system, a chemotherapeutic drug (doxorubicin, DOX) and an optotheranostic agent (indocyanine green, ICG) were co-loaded in bovine serum albumin (BSA) via a hydrophobic-interaction-induced self-assembly to form stable DOX&ICG@BSA nanoparticles. After the decoration of a surface layer composed of a tumor-targeting aptamer (AS1411) and a cell-penetrating peptide (KALA), the obtained DOX&ICG@BSA-KALA/Apt nanoparticles exhibit a significantly improved multimodal cancer therapeutic efficiency due to the enhanced cancer cellular uptake mediated by AS1411 and KALA. In vitro and in vivo studies show that the multimodal theranostic system can efficiently inhibit tumor growth. In addition, the near-infrared fluorescent/photothermal dual-mode imaging enables accurate visualization of the therapeutic action in tumor sites. This study provides a facile strategy to construct self-assembled multimodal theranostic systems, and the functional protein-based theranostic system prepared holds great promise in multimodal cancer therapeutics.

Plug-and-Play Continuous Gas Flow Assembly of Cysteine-Inserted AuCu Nanobimetals for Folate-Receptor-Targeted Chemo-Phototherapy

Conjugatable nanobimetals exhibiting broadband light absorption for use as phototherapeutic platforms were assembled via a plug-and-play continuous gas flow route. Electrically produced AuCu nanobunches (NBs) under nitrogen gas flow were directly injected into cysteine (cys) solution through gas pressurization to mechanically spray the solution (AuCu into cys droplets). The sprayed droplets were then exposed to 185 nm UV light (higher photon energy [6.2 eV] than the work functions of Au [5.1 eV] and Cu [4.7 eV]) to initiate photoionization of AuCu NBs for subsequent electrostatic reaction with the SH^- group of cys to form cys-inserted AuCu (AuCu-cys) platforms in a single-pass gas stream. These platforms exhibited broadband light absorption spectra because of hybridized interparticle plasmonic coupling and could be conjugated to folic acid (FA) when dispersed in FA solution to form highly dispersible, biocompatible, and cancer-targetable AuCu-cys-FA. This material was suitable for use in targeted phototherapy of folate-receptor (FR)-rich cancers via FR-mediated endocytosis, and loading doxorubicin (DOX) into AuCu-cys-FA (i.e., AuCu-cys-DOXFA) facilitated chemo-phototherapy because of photoresponsive anticancer drug release upon induction of hyperthermia.

A multiscale flexible pressure sensor based on nanovesicle-like hollow microspheres for micro-vibration detection in non-contact mode

To detect micro-vibration, flexible pressure sensors require that the sensing materials possess superior sensitivity in non-contact sensing mode. One type of matter, nanovesicles, has the characteristics of hollow spheres and crack junctions in a single body, and provides an exciting bionic idea to explore high-sensitivity sensing materials. Hence, in this study, novel hollow microspheres with a hierarchical nanovesicle-like architecture are designed, prepared via a controlled strategy of adjusting the surface energy, and employed to fabricate multiscale flexible pressure sensors that display a high response sensitivity of 11.3 kPa-1 and a low detection limit of 5.5 Pa with good stability for 2500 cycles. The working mechanism can be deduced as the synergistic effects from the stress concentration of microstructural patterns and the successive deformation of the nanovesicle-like structure, which is revealed by controlled experiments and finite element method simulations. The as-assembled flexible pressure sensor is used to detect the dynamic micro-vibration signals caused by fluid motion (water flow and airflow) and inelastic/elastic collision in non-contact mode, revealing good sensitivity, repeatability and stability. This work provides theoretical and experimental evidence for the development of hierarchical structure-based highly sensitive flexible sensors in the future.

A scalable on-demand platform to assemble base nanocarriers for combination cancer therapy

Chemophototherapy is an advanced cancer therapeutic that uses photothermal nanocarriers (NCs) responsive to near-infrared (NIR) light. For the past decade, chemophototherapy has been investigated intensively for clinical translation, and continuous-flow production of biofunctional compounds (NCs, drugs, probes, nanocomposites) has received increasing attention for future therapeutics. However, in situ supply of a stimuli-responsive inorganic core and subsequent tight drug loading on the core are challenging tasks in the practical use of on-demand nanomedicines. Thus, in this study, we designed and evaluated both in vitro and in vivo models of an aero-hydro-aero single-pass production system for chemophotothermally active NCs. We prepare tightly-drug-loadable cores (titanium peroxide [yTiO2] nanovesicles [NVs]) using hydrogen flame pyrolysis of vaporized TiCl4 (aero) and successive ultrasonic H2O2 treatment (hydro). The NVs formed were incorporated with graphene oxide (GO), doxorubicin (D), and polyethylene glycol (P) in a spray to form GO-yTiO2@DP NCs (aero). The NVs' tight DP loading and endothermic effect induced greater, sustained D release and tumor-selective distribution, even for hyperthermic activity. The results showed the route developed may be a stepping stone to scalable, reconfigurable production for on-demand chemophotothermal therapeutics.