Kaiyong Cai

The effective management of osteoarthritis (OA) remains a formidable clinical challenge due to a chronically inflamed joint microenvironment and the limited self‐regenerative capacity of articular cartilage. To address these barriers, we developed an ultrasound‐responsive core–shell microsphere platform engineered via a customized microfluidic capillary device. This system features a kartogenin (KGN)‐loaded poly(lactic‐co‐glycolic acid) (PLGA) core encapsulated within a sodium alginate shell enriched with tin disulfide (SnS) nanosheets (SSN). Following intra‐articular injection, non‐invasive ultrasound stimulation triggers the localized SSN to generate low‐concentration hydrogen gas (H ₂ ). This in situ H ₂ generation rapidly scavenges excess reactive oxygen species to restore redox homeostasis, thereby mitigating mitochondrial dysfunction and preserving chondrocyte viability. Consequently, this targeted antioxidative intervention suppresses pro‐inflammatory cytokine secretion and polarizes synovial macrophages toward a pro‐regenerative M2 phenotype. Within this newly stabilized microenvironment, the sustained release of KGN from the PLGA core successfully reverses extracellular matrix metabolic imbalances to promote cartilage repair. In a rat model of OA, this dual‐functional, spatiotemporally controlled platform profoundly halted joint degeneration and preserved histological cartilage integrity. Collectively, this ultrasound‐triggered core–shell microsphere system offers a highly promising, disease‐modifying strategy for comprehensive OA therapy.

Scaffold-based bone tissue engineering (BTE) represents a pivotal strategy in regenerative medicine, offering substantial promise for repairing damaged bone. These scaffolds provide essential structural support and promote new bone formation by mimicking the native extracellular matrix (ECM). The rational design of an ideal scaffold requires careful balancing of biomaterial properties with biomechanical performance. Natural polymers have gained considerable attention in this context due to their inherent bioactivity, biocompatibility, and tunable mechanical properties. Their key advantage lies in their ability to replicate the complex architecture and function of bone ECM, thereby facilitating cellular interactions and tissue ingrowth. Recent progress in the processing and assembly of natural polymers has enabled innovative scaffold designs, including hydrogels as well as fibrous and porous architectures. These advances allow for the fabrication of scaffolds with precisely tailored features, such as optimal stiffness, controlled pore sizes, and surface topographies conducive to cell adhesion and differentiation. Furthermore, degradation kinetics can be adjusted to match the rate of new tissue formation. This review provides a comprehensive examination of the role of natural polymers in BTE. It critically discusses state-of-the-art fabrication techniques and highlights the critical physicochemical and biological properties that determine scaffold performance. By consolidating these key aspects, the review aims to identify current challenges and outline future directions for the development of natural polymer-based scaffolds. Ultimately, this work seeks to offer practical guidance for the rational design and translational advancement of these materials in bone regeneration.

Chronic non‐healing diabetic wounds pose a significant clinical challenge, attributed to a pathogenic microenvironment characterized by persistent inflammation, excessive accumulation of reactive oxygen species, impaired angiogenesis, and mitochondrial dysfunction. Herein, we reported a novel multifunctional hydrogel dressing aimed at promoting diabetic wound healing through the synergistic action of anti‐inflammatory, antioxidant, angiogenic, and metabolic regulatory mechanisms. First, nicotinamide mononucleotide (NMN)‐templated magnesium phosphate nanoparticles (NMP NPs) were synthesized through a biomimetic mineralization strategy. Subsequently, the NMP NPs were incorporated into a double‐network hydrogel that formed by dynamic Schiff base crosslinking and photocuring of methacrylated gelatin and oxidized dextran, resulting in a multifunctional composite hydrogel (NMP/GO) with tissue adhesion properties and multiple biological activities. The NMP/GO hydrogel dressing slowly releases Mg ²⁺ ions and NMN within the diabetic microenvironment, where Mg ²⁺ modulates inflammatory responses and promotes angiogenesis, while NMN restores redox balance and ameliorates mitochondrial dysfunction. Owing to this synergistic effect, the NMP/GO hydrogel dressing significantly promotes diabetic wound healing by reducing inflammation, mitigating oxidative stress, restoring mitochondrial function, and enhancing angiogenic potential. Consequently, the NMP/GO hydrogel dressing presents a promising therapeutic strategy for advanced diabetic wound management with high translational potential.

This study proposed a new strategy for simultaneous catalytic conversion of wheat straw with a deep eutectic solvent-assisted ball milling method at high solid content (20%) conditions, thereby improving monosaccharide yield and exergy efficiency. After mechanical shearing by ball milling, the crystallinity of wheat straw was reduced and the porosity increased by 12.7%. Meanwhile, 13C NMR and 2D HSQC NMR demonstrated that low DES loadings in this strategy can still effectively cleave β-O-4 bonds and reduce hydrogen-bond strength within cellulose molecules and LCC. Pearson correlation coefficient matrix analysis showed that increased pores from mechanical shearing and DES-induced delignification significantly promoted the saccharification rate. After 72 h of enzymatic hydrolysis, the monosaccharide concentration reached 30.7 g/L, 6.1 times that of the control. The overall exergy efficiency of wheat straw pretreated by the mechanochemical process reached 85.7%, indicating that the proposed strategy is suitable for monosaccharide production while maintaining low exergy loss and has great application potential in sustainable biorefining plants.

The refractory healing of diabetic wounds represents a major clinical challenge, primarily attributed to a vicious cycle formed by persistent bacterial infection, excessive oxidative stress, and a dysregulated immune microenvironment.

A magnetically responsive anisotropic hydrogel coating guides BMSCs alignment and promotes osteogenic differentiation on Ti implants.

Rheumatoid arthritis (RA) is a systemic autoimmune disease that causes serious joint damage and functional loss, which is predominantly associated with the aberrant activation of synovial macrophages. Herein, we report an injectable ion-coordinated bionic lubricant to efficiently reprogram synovial macrophages into pro-regenerative phenotypes for RA treatment. For this purpose, rhein (Rh)-modified PEGylated liposomes were integrated with coenzyme Q10 (CoQ10) for macrophage-targeted delivery (LipQ10-Rh), which were subsequently embedded into dynamic hyaluronic acid (HA)-based hydrogel matrices cross-linked by acylhydrazone bonding and Zn2+ ion-mediated coordination (HALZ). Owing to the intrinsic reversibility of the dynamic bonding network, the HALZ lubricant could be facilely injected into RA-affected joint cavity and provide immediate relief through biolubrication. Meanwhile, the LipQ10-Rh liposomes and Zn ions could be gradually released from the dynamic hydrogels and taken in by synovial macrophages, where the Zn ions could activate the anti-inflammatory metabolism while CoQ10 alleviated mitochondrial ROS stress to restore their reparative functions, which acted in a cooperative manner to reprogram the inflammatory synovial macrophages into pro-regenerative phenotypes. In vivo results evidently suggested that the injectable HALZ biolubricant efficiently abolished RA-associated joint damage on rat models in a durable manner, providing an approach for improving RA recession in the clinic.

Correction for ‘Nanosheet-pore topographical titanium substrates: a biophysical regulator of the fate of mesenchymal stem cells’ by Kui Xu et al. , J. Mater. Chem. B , 2016, 4 , 1797–1810, https://doi.org/10.1039/C5TB02391B.

Correction for ‘Influence of strontium ions incorporated into nanosheet-pore topographical titanium substrates on osteogenic differentiation of mesenchymal stem cells in vitro and on osseointegration in vivo ’ by Kui Xu et al. , J. Mater. Chem. B , 2016, 4 , 4549–4564, https://doi.org/10.1039/C6TB00724D.

The combination of chemotherapy and immunotherapy represents a promising approach that leverages their complementary benefits. However, the side effects resulting from off-target effects and the low efficiency of immune activation remain a significant concern. Herein, we developed a zinc-doped calcium phosphate (ZCP) nanocarrier for the delivery of the chemotherapeutic drug doxorubicin (DOX). By further encapsulating whole proteins from 4T1 breast cancer cells, we constructed a novel nanodrug delivery system named ZCPDM. This system enables specific targeting of tumor cells and undergoes intracellular degradation to release DOX, Zn²⁺, and Ca²⁺. As a chemotherapeutic agent, DOX induces apoptosis while significantly elevating intracellular reactive oxygen species (ROS), thereby enhancing cytotoxicity. This leads to DNA damage and the release of chromosomal fragments. These DNA fragments, together with Zn²⁺, activate the cGAS-STING signaling pathway and trigger pyroptosis, which promotes more efficient recognition and clearance of tumor cells by the immune system. Through these dual mechanisms, ZCPDM effectively combines chemotherapy and immunotherapy. The anti-tumor efficacy and underlying mechanisms were validated at the cellular level. Furthermore, studies in tumor-bearing mice demonstrated its robust anti-tumor performance and ability to suppress tumor recurrence, along with good biosafety. This targeted drug delivery system achieves safe and synergistic chemo-immunotherapy through homologous targeting-mediated pyroptosis and activation of the cGAS-STING pathway, offering a novel and promising strategy for cancer treatment.