Fe3O4 Nanoparticles That Modulate the Polarisation of Tumor-Associated Macrophages Synergize with Photothermal Therapy and Immunotherapy (PD-1/PD-L1 Inhibitors) to Enhance Anti-Tumor Therapy.

Introduction: Traditional surgical resection, radiotherapy, and chemotherapy have been the treatment options for patients with head and neck squamous cell carcinoma (HNSCC) over the past few decades. Nevertheless, the five-year survival rate for patients has remained essentially unchanged, and research into treatments has been relatively stagnant. The combined application of photothermal therapy (PTT) and immunotherapy for treating HNSCC has considerable potential. Methods: Live-dead cell staining and CCK-8 assays proved that Fe3O4 nanoparticles are biocompatible in vitro. In vitro, cellular experiments utilized flow cytometry and immunofluorescence staining to verify the effect of Fe3O4 nanoparticles on the polarisation of tumor-associated macrophages. In vivo, animal experiments were conducted to assess the inhibitory effect of Fe3O4 nanoparticles on tumor proliferation under the photothermal effect in conjunction with BMS-1. Tumour tissue sections were stained to observe the effects of apoptosis and the inhibition of tumor cell proliferation. The histological damage to animal organs was analyzed by hematoxylin and eosin (H&E) staining. Results: The stable photothermal properties of Fe3O4 nanoparticles were validated by in vitro cellular and in vivo animal experiments. Fe3O4 photothermal action not only directly triggered immunogenic cell death (ICD) and enhanced the immunogenicity of the tumor microenvironment but also regulated the expression of tumor-associated macrophages (TAMs), up-regulating CD86 and down-regulating CD206 to inhibit tumor growth. The PD-1/PD-L1 inhibitor promoted tumor suppression, and reduced tumor recurrence and metastasis. In vivo studies demonstrated that the photothermal action exhibited a synergistic effect when combined with immunotherapy, resulting in significant suppression of primary tumors and an extension of survival. Conclusion: In this study, we applied Fe3O4 photothermolysis in a biomedical context, combining photothermolysis with immunotherapy, exploring a novel pathway for treating HNSCC and providing a new strategy for effectively treating HNSCC.

A functional study of zinc-titanium coatings and exploration of the intrinsic correlation between angiogenesis and osteogenesis.

With the development of implant applications, osseointegration has become a criterion for implant success. A good blood supply is essential for successful osseointegration. To improve the pro-angiogenic ability of the implants, in this experiment we introduced zinc into the titanium coating. The physical morphology, biocompatibility, pro-angiogenic ability, and osteogenic effect of the zinc-containing titanium coatings were investigated. The pro-angiogenic effect of zinc ions was determined, and the intrinsic link between angiogenesis and osteogenesis under the effect of zinc ions was investigated. Zinc-containing titanium coating was prepared using a micro-arc oxidation (MAO) technique. The physical properties of the coating materials were determined by analyzing the microstructure, roughness, hydrophilic properties, constituent elements, and ionic release of the coating. The biocompatibility of the coating materials was examined using apoptosis and proliferation assays of human umbilical vein endothelial cells (HUVECs). The pro-angiogenic function and osteogenic ability of the zinc-containing coating were investigated by CD31 immunofluorescence staining and quantitative polymerase chain reaction (q-PCR) assay. The optimal concentration of zinc ions for pro-angiogenesis was screened by ion assay. Conditioned media (CM) were prepared for the experiments. The intrinsic link between angiogenesis and osteogenesis was determined by q-PCR to detect the expression of genes related to HUVECs and BMSCs after culture in CM. The prepared Zn-containing micro-arc oxide coatings were shown to have good physical properties, stable Zn2+ release ability, and biocompatibility, as well as good angiogenic and osteogenic potential. In addition, ion experiments confirmed that 60 µM Zn2+ exhibited the best angiogenic effect; more importantly, a mutual promotion between angiogenesis and osteogenesis regeneration in the Zn2+ microenvironment was also found. The introduction of Zn2+ improved the implants' functionality and laid the foundation for the clinical application of Zn2+ pro-angiogenesis.

Multidynamic Osteogenic Differentiation by Effective Polydopamine Micro-Arc Oxide Manipulations.

Introduction: The nanostructural modification of the oral implant surface can effectively mimic the morphology of natural bone tissue, allowing osteoblasts to achieve both proliferation and differentiation capabilities at the bone interface of the dental implant. To improve the osteoinductive activity on the surface of titanium implants for rapid osseointegration, we prepared a novel composite coating (MAO-PDA-NC) by micro-arc oxidation technique and immersion method and evaluated the proliferation, adhesion, and osteogenic differentiation of osteoblasts on this coating. Methods: The coatings were prepared by micro-arc oxidation (MAO) technique and immersion method, and characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) for different coatings; the loading of PDA was examined using Fourier transform infrared spectroscopy (FTIR); the ion release capacity of the coatings was determined by inductively coupled plasma emission spectrometry (ICP-OES); the interfacial bonding of the coatings was examined using nanoscratch experiment strength. The cytotoxicity of the coating was examined by live/dead staining kit; cell proliferation viability was examined by CCK-8 kit; adhesion and osteogenic effect of the coating were examined by immunofluorescence staining and RT-PCR; osteogenic differentiation was examined by alkaline phosphatase staining. Results: The surface morphology of titanium implants was modified by micro-arc oxidation technology, and a new MAO-PDA-NC composite coating was successfully prepared. The results showed that the MAO-PDA-NC coating not only optimized the physical and chemical properties of the titanium implant surface but also significantly stimulated the biological properties of osteoblast adhesion, proliferation, and osteogenic differentiation on the coating surface. Conclusion: These results show that MAO-PDA-NC composite coating can significantly improve the surface properties of titanium implants and achieve a stable bond between implant and bone tissue, thus accelerating early osseointegration.

Inhibition of Inflammatory Response and Promotion of Osteogenic Activity of Zinc-Doped Micro-Arc Titanium Oxide Coatings.

An early and sustained immune response can lead to chronic inflammation after the implant is placed in the body. The implantable materials with immunomodulatory effects can reduce the body's immune response and promote the formation of ideal osseointegration between the implants and bone tissue. In this study, zinc-coated titanium micro-arc oxide coating was prepared on titanium surface by micro-arc oxidation. The physical properties, anti-inflammation, and osteogenesis of the material were evaluated. We have physically characterized the surface structure of the coatings by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM) and detected the release of Zn2+ from the coating surface by inductively coupled optical plasma emission spectrometry (ICP-OES). The BMSCs were inoculated on the surface of the coating, and the biocompatibility of the coating was evaluated by CCK-8 analysis and living and dead cell staining. The osteogenic effect of the layer on BMSCs was evaluated by alkaline phosphatase (ALP) assays, osteocalcin (OCN) immunofluorescence, and quantitative polymerase chain reaction (q-PCR). The survival status of RAW264.7 on the coating surface and the mRNA expression of the associated proinflammatory markers, tumor necrosis factor-α (TNF-α), cluster of differentiation 86 (CD86), and inducible nitric oxide (INOS) were detected by CCK-8 analysis and q-PCR. In parallel, the cell counting kit-8 (CCK-8) analysis and q-PCR screened and evaluated the effective concentration of Zn2+ anti-inflammatory in vitro. The results show that the coating has good physical characterization, and Zn is uniformly bound to the surface of titanium and shows stable release and good biocompatibility to BMSCs, downregulating the expression of inflammation-related genes promoting the bone formation of BMSCs. We have successfully prepared zinc-coated micro-arc titanium oxide coating on the titanium surface, which has good osteogenesis and great anti-inflammatory potential and provides a new way for osseointegration in the implant.

Incorporation of Zinc into Binary SiO2-CaO Mesoporous Bioactive Glass Nanoparticles Enhances Anti-Inflammatory and Osteogenic Activities.

During the healing and repair of bone defects, uncontrolled inflammatory responses can compromise bone regeneration. Biomaterials with anti-inflammatory activity are favorable for bone tissue regeneration processes. In this work, multifunctional Zn-containing mesoporous bioactive glass nanoparticles (Zn-MBGs) exhibiting favorable osteogenic and anti-inflammatory activities were produced employing a sol-gel method. Zn-MBGs exhibited a mesoporous spherical shape and nanoscale particle size (100 ± 20 nm). They were degradable in cell culture medium, and could release Si, Ca, and Zn in a sustained manner. Zn-MBGs also exhibited a concentration-dependent cellular response. The extract of Zn-MBGs obtained by incubation at 0.1 mg/mL (in culture medium) for 24 h could enhance in vitro mineralization, alkaline phosphatase activity, the expression of osteogenesis-related genes, and the production of intracellular protein osteocalcin of rat bone marrow stromal cells (BMSCs). Moreover, the extract of Zn-MBGs at 0.1 mg/mL could significantly downregulate the expression of inflammatory genes and the production of inducible nitric oxide in RAW 264.7 cells, particularly under stimulation of inflammatory signals interferon-γ (IFN-γ) and lipopolysaccharide (LPS). Zn-MBGs also inhibited the pro-inflammatory M1 polarization of RAW264.7 cells induced by LPS and IFN-γ. In summary, we successfully synthesized Zn-MBGs with concentration-dependent osteogenic and anti-inflammatory activities. Zn-MBGs show their great potential in immunomodulation strategies for bone regeneration, representing a multifunctional biomaterial that can be applied to regenerate bone defects under inflammatory conditions.