Photodynamic Therapy: A New Treatment Modality for Rheumatoid Arthritis: Combined Photothermal and Photodynamic Therapy Using Cu7.2 S4 Nanoparticles (Adv. Healthcare Mater. 14/2018)

Isocorrole-Loaded Polymer Nanoparticles for Photothermal Therapy under 980 nm Light Excitation

Photothermal therapy (PTT) is a promising treatment option for diseases, including cancer, arthritis, and periodontitis. Typical photothermal agents (PTAs) absorb light in the near-infrared (NIR)-I region of 650-900 nm with a predominant focus around 800 nm, as these wavelengths are minimally absorbed by water and blood in the tissue. Recently, interest has grown in developing nanomaterials that offer more efficient photothermal conversion and that can be excited by light close to or within the NIR-II window of 1000-1700 nm, which offers less absorption by melanin. Herein, we report on the development of 5,5-diphenyl isocorrole (5-DPIC) complexes containing either Zn(II) or Pd(II) (Zn[5-DPIC] and Pd[5-DPIC], respectively) that absorb strongly across the 850-1000 nm window. We also show that poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with these designer isocorroles exhibit low toxicity toward triple-negative breast cancer (TNBC) cells in the dark but enable efficient heat production and photothermal cell ablation upon excitation with 980 nm light. These materials represent an exciting new platform for 980 nm activated PTT and demonstrate the potential for designer isocorroles to serve as effective PTAs.

NIR-PTT/ROS-Scavenging/Oxygen-Enriched Synergetic Therapy for Rheumatoid Arthritis by a pH-Responsive Hybrid CeO2-ZIF-8 Coated with Polydopamine

Rheumatoid arthritis (RA) is an inflammatory type of arthritis that causes joint pain and damage. The inflammatory cell infiltration (e.g., M1 macrophages), the poor O₂ supply at the joint, and the excess reactive oxygen species (ROS)-induced oxidative injury are the main causes of RA. We herein report a polydopamine (PDA)-coated CeO₂-dopped zeolitic imidazolate framework-8 (ZIF-8) nanocomposite CeO₂-ZIF-8@PDA (denoted as CZP) that can synergistically treat RA. Under near-infrared (NIR) light irradiation, PDA efficiently scavenges ROS and results in an increased temperature in the inflamed area because of its good light-to-heat conversion efficiency. The rise of temperature serves to obliterate hyper-proliferative inflammatory cells accumulated in the diseased area while vastly promoting the collapse of the acidic-responsive skeleton of ZIF-8 to release the encapsulated CeO₂. The released CeO₂ exerts its catalase-like activity to relieve hypoxia by generating oxygen via the decomposition of H₂O₂ highly expressed in the inflammatory sites. Thus, the constructed CZP composite can treat RA through NIR-photothermal/ROS-scavenging/oxygen-enriched combinative therapy and show good regression of pro-inflammatory cytokines and hypoxia-inducible factor-1α (HIF-1α) in vitro and promising therapeutic effect on RA in rat models. The multimodal nano-platform reported herein is expected to shed light on the design of synergistic therapeutic nanomedicine for effective RA therapy.

Au nanoclusters modulated macrophages polarization and synoviocytes apoptosis for enhanced rheumatoid arthritis treatment

The persistent progression of synovial inflammation and cartilage destruction was contributed to the cross-talk of pro-inflammatory macrophages and activated fibroblast-like synoviocytes (FLS) in synovial microenvironment. In this work, a structurally...

Improved SERS activity of non-stoichiometric copper sulfide nanostructures related to charge-transfer resonance

The low enhancement factor of semiconductor SERS substrates is a major obstacle for their practical application. Therefore, there is a need to explore the facile synthesis of new SERS substrates and reveal the SERS enhancement mechanism. Here, we develop a simple, facile and low-cost two-step method to synthesize copper sulfide based nanostructures with different Cu_7.2S₄ contents. The as-synthesized sample is composed of nanosheets with the CuS phase structure. With the increase of the annealing temperature to 300 °C, the CuS content gradually decreases and disappears, and the content of Cu_7.2S₄ and CuSO₄ appears and gradually increases. At the annealing temperature of 350 °C, only CuSO₄ exists. Compared with pure CuS or pure CuSO₄, the detection limit of R6G molecules is the lowest for the composite sample with a higher content of Cu_7.2S₄, indicating that the introduction of non-stoichiometric Cu_7.2S₄ can improve the SERS performance and the higher content of Cu_7.2S₄ leads to a higher SERS activity. Furthermore, to investigate the SERS mechanism, the energy band structures and energy-level diagrams of different probe molecules over CuS, Cu_7.2S₄ and Cu_xS are studied by DFT calculations. Theoretical calculations indicate that the excellent SERS behavior depends on charge transfer resonance. Our work provides a general approach for the construction of excellent metal compound semiconductor SERS active substrates.