The treatment of bone defects remains a substantial clinical challenge due to the lack of spatiotemporal management of the immune microenvironment, revascularization, and osteogenic differentiation. Herein, deferoxamine (DFO)-loaded black phosphorus nanosheets decorated by polydopamine layer are prepared (BPPD) and compounded into gelatin methacrylate/sodium alginate methacrylate (GA) hybrid hydrogel as a smart-responsive therapeutic system (GA/BPPD) for accelerated bone regeneration. The BPPD nanocomposites served as bioactive components and near-infrared (NIR) photothermal agents, which conferred the hydrogel with excellent NIR/pH dual-responsive properties, realizing the stimuli-responsive release of DFO and PO4 3 - during bone regeneration. Under the action of NIR-triggered mild photothermal therapy, the GA/BPPD hydrogel exhibited a positive effect on promoting osteogenesis and angiogenesis, eliminating excessive reactive oxygen species, and inducing macrophage polarization to the M2 phenotype. More significantly, through macrophage M2 polarization-induced osteoimmune microenvironment, this hydrogel platform could also drive functional cytokine secretion for enhanced angiogenesis and osteogenesis. In vivo experiments further demonstrated that the GA/BPPD system could facilitate bone healing by attenuating the local inflammatory response, increasing the secretion of pro-healing factors, stimulating endogenous cell recruitment, and accelerating revascularization. Collectively, the proposed intelligent photothermal hydrogel platform provides a promising strategy to reshape the damaged tissue microenvironment for augmented bone regeneration.

Smart-Responsive Multifunctional Therapeutic System for Improved Regenerative Microenvironment and Accelerated Bone Regeneration via Mild Photothermal Therapy.

The clinical applications of currently used photosensitizers are limited by high costs, inconvenient preparation, suboptimal biodegradability, and a lack of biological activity. Humic acids (HAs) show photothermal activity and can be used as a photosensitizer for photothermal therapy. In the presence of various functional groups, HAs are endowed with anti-inflammatory and antioxidant activities. The solubility of HAs is dependent on the pH value, which is soluble in neutral to alkaline conditions and undergoes a conformational change to a coiled and compact structure in acidic conditions. Additionally, Cu2+ is an emerging therapeutic agent for cutaneous wounds and can be chelated by HAs to form complexes. In this study, we explore the ability of HAs to modulate the inflammatory response, particularly macrophage polarization, and the potential underlying mechanism. We fabricate a near-infrared (NIR)/pH dual-responsive Cu-HAs nanoparticle (NP)-based poly(vinyl alcohol) (PVA) hydrogel film loaded with SEW2871 (SEW), a macrophage recruitment agent, to treat bacteria-infected cutaneous wounds. The results show that HAs could promote M2 macrophage polarization in a dose-dependent manner. The Cu-HAs NPs successfully eradicated bacterial infection through NIR-induced local hyperthermia. This PVA@Cu-HAs NPs@SEW hydrogel film improves tissue regeneration by promoting M2 macrophage polarization, alleviating oxidative stress, enhancing angiogenesis, and facilitating collagen deposition. These findings highlight the therapeutic potential of PVA@Cu-HAs NPs@SEW hydrogel film for the treatment of bacterially infected cutaneous wound healing. 

Waste to Wealth: Near-Infrared/pH Dual-Responsive Copper-Humic Acid Hydrogel Films for Bacteria-Infected Cutaneous Wound Healing.

Bone defects are encountered substantially in clinical practice, and bionic scaffolds represent a promising solution for repairing bone defects. However, it is difficult to fabricate scaffolds with bionic structures and reconstruct the microenvironment to fulfill the satisfying repair effects. In this review article, we first discuss various strategies for the design and construction of bionic scaffolds to promote bone defect repair, especially including the structural construction of the scaffold and the integration of bioactive substances together with the application of external stimuli. We then discuss the roles of artificial intelligence and medical imaging in aiding clinical treatment. Finally, we point out the challenges and future outlooks in developing multifunctional bone repair scaffolds, aiming to provide insights for improving bone regeneration efficacy and accelerating clinical translation.

Advanced strategies of scaffolds design for bone regeneration

Abstract The repair and functional reconstruction of bone defects resulting from severe trauma, surgical resection, degenerative disease, and congenital malformation pose significant clinical challenges. Bone tissue engineering (BTE) holds immense potential in treating these severe bone defects, without incurring prevalent complications associated with conventional autologous or allogeneic bone grafts. Three‐dimensional (3D) printing technology enables control over architectural structures at multiple length scales and has been extensively employed to process biomimetic scaffolds for BTE. In contrast to inert and functional bone grafts, next‐generation smart scaffolds possess remarkable ability to mimic the dynamic nature of native extracellular matrix (ECM), thereby facilitating bone repair and regeneration. Additionally, they can generate tailored and controllable therapeutic effects, such as antibacterial or antitumor properties, in response to exogenous and/or endogenous stimuli. This review provides a comprehensive assessment of the progress of 3D‐printed smart scaffolds for BTE applications. It begins with an introduction to bone physiology, followed by an overview of 3D printing technologies utilized for smart scaffolds. Notable advances in various stimuli‐responsive strategies, therapeutic efficacy, and applications of 3D‐printed smart scaffolds are discussed. Finally, the review highlights the existing challenges in the development and clinical implementation of smart scaffolds, as well as emerging technologies in this field. This article is protected by copyright. All rights reserved 

Recent Advances in 3D Printing of Smart Scaffolds for Bone Tissue Engineering and Regeneration

The immune checkpoint blockade (ICB) antibody immunotherapy has demonstrated clinical benefits for multiple cancers. However, the efficacy of immunotherapy in tumors is suppressed by deficient tumor immunogenicity and immunosuppressive tumor microenvironments. Pyroptosis, a form of programmed cell death, can release tumor antigens, activate effective tumor immunogenicity, and improve the efficiency of ICB, but efficient pyroptosis for tumor treatment is currently limited. Herein, we show a mild hyperthermia-enhanced pyroptosis-mediated immunotherapy based on hollow carbon nanozyme, which can specifically amplify oxidative stress-triggered pyroptosis and synchronously magnify pyroptosis-mediated anticancer responses in the tumor microenvironment. The hollow carbon sphere modified with iron and copper atoms (HCS-FeCu) with multiple enzyme-mimicking activities has been engineered to induce cell pyroptosis via the radical oxygen species (ROS)-Tom20-Bax-Caspase 3-gasdermin E (GSDME) signaling pathway under light activation. Both in vitro and in vivo antineoplastic results confirm the superiority of HCS-FeCu nanozyme-induced pyroptosis. Moreover, the mild photothermal-activated pyroptosis combining anti-PD-1 can enhance antitumor immunotherapy. Theoretical calculations further indicate that the mild photothermal stimulation generates high-energy electrons and enhances the interaction between the HCS-FeCu surface and adsorbed oxygen, facilitating molecular oxygen activation, which improves the ROS production efficiency. This work presents an approach that effectively transforms immunologically "cold" tumors into "hot" ones, with significant implications for clinical immunotherapy.

A Mild Hyperthermia Hollow Carbon Nanozyme as Pyroptosis Inducer for Boosted Antitumor Immunity.

Bone fractures are often companied with poor bone healing and high rates of infection. Early recruitment of mesenchymal stem cells (MSCs) is critical for initiating efficient bone repair, and mild thermal stimulation can accelerate the recovery of chronic diseases. Here, a bioinspired, staged photothermal effect-reinforced multifunctional scaffold was fabricated for bone repair. Uniaxially aligned electrospun polycaprolactone nanofibers were doped with black phosphorus nanosheets (BP NSs) to endow the scaffold with excellent near-infrared (NIR) responsive capability. Apt19S was then decorated on the surface of the scaffold to selectively recruit MSCs toward the injured site. Afterward, microparticles of phase change materials loaded with antibacterial drugs were also deposited on the surface of the scaffold, which could undergo a solid-to-liquid phase transition above 39 °C, triggering the release of payload to eliminate bacteria and prevent infection. Under NIR irradiation, photothermal-mediated up-regulation of heat shock proteins and accelerated biodegradation of BP NSs could promote the osteogenic differentiation of MSCs and biomineralization. Overall, this strategy shows the ability of bacteria elimination, MSCs recruitment, and bone regeneration promotion with the assistance of photothermal effect in vitro and in vivo, which emphasizes the design of a bioinspired scaffold and its potential for a mild photothermal effect in bone tissue engineering.

Bioinspired Mild Photothermal Effect-Reinforced Multifunctional Fiber Scaffolds Promote Bone Regeneration.

In this paper, carbon fibers (CF) with different electrochemical treatment levels were obtained by changing the parameters of electrochemical treatment, and the effect of electrochemical treatment levels on the surface properties of CF was studied by scanning electron microscope, atomic force microscopy and X-ray photoelectron spectroscopy. The interfacial shear strength (IFSS) of CF with different electrochemical treatment levels were characterized by single fiber-composite fragmentation. The effects of electrochemical treatment on the mechanical properties of CF were investigated by monofilament tensile test and composite laminate 0° tensile test. Finally, the carbon fibers were compounded with epoxy resin to prepare composite laminates, whose effect on the macroscopic mechanical properties of the composite, such as short beam shear strength (SBSS) and compression after impact (CAI) strength, was studied. As a result, with the increase of the level of electrochemical treatment, the surface roughness and chemical activity of CF increased first and then decreased, while the surface energy shows a gradually increasing trend. The IFSS of CF-BX shows a gradually increasing trend, while that of the CF-SX shows a trend of increasing first and then remaining basically unchanged, while SBSS shows the same trend. The monofilament tensile test and composite laminate 0° tensile test showed that the electrochemical treatment did not have a significant effect on the mechanical properties of CF. The compression after impact test showed that with the enhancement of the electrochemical treatment, the CAI of the composite laminates increased first and then remained roughly unchanged. 

Influence of the electrochemical treatment level of carbon fibers on the compression after impact property of carbon fiber/epoxy composites

The solidification of chromium-contaminated soil using polyurethane (PU) was systematically investigated. The unconfined compression test was conducted to investigate the effects of the curing time, PU dosage and the content of chromium ions on the unconfined compressive strength (UCS) of chromium-contaminated soil. The effect of the PU dosage on the pore structure was investigated using nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM), and the mechanism of strength change was revealed by combining the strength law with the pore structure development law. In addition, the ability of the PU to solidify the chromium-contaminated soil was studied by the toxicity characteristic leaching procedure (TCLP). According to the above test results, the UCS and the ability of the PU to solidify the chromium ions increased with the increase in curing time. The NMR tests showed that with the increase in PU dosage, the porosity decreased and the soil became more compact, hence increasing the strength. When the chromium ion content was 2000 mg/kg and the PU dosage was 8%, the strength of the sample was 0.37 MPa after curing for 24 h, which met the requirement of 0.35 MPa set by the U.S. Environmental Protection Agency. Consequently, PU is a solidification agent with high-early strength.

/pdf/studying-the-properties-of-chromium-contaminated-soil-3oku5t4t.pdf

Studying the Properties of Chromium-Contaminated Soil Solidified by Polyurethane

Effect of Chemical Cross-Links on the Mechanical and Thermal Properties of Graphene-Reinforced Polymer Matrix Composites

Cemented soil fill is a new backfilling technology developed for the problems of narrow foundation trenches and uncompacted backfilling. It has good fluidity before solidification and higher strength and stiffness after solidification. This type of fill materials makes full use of the waste soils. The proportioning test was carried out on excavated soil on a construction site. Liquid property tests and unconfined compressive strength tests was carried out. The results show that the cemented soil fill can meet the requirement of foundation trenches backfilling, which has great prospect for future applications.

https://iopscience.iop.org/article/10.1088/1742-6596/2148/1/012066/pdf

Physical and Mechanical Properties of Cemented Soil Fill At Liquid and Hardened States

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Junjie Chen

Author Tools

Chat about Author