Tissue repair is challenged by inefficient cellular infiltration and prolonged inflammation. Herein, the mesoporous polydopamine nanoparticles were loaded with spermidine and then encapsulated in agarose, which were incorporated into the oxidized hyaluronic acid crosslinked collagen matrix to fabricate NIR-activated hydrogel (DOCH@P) by the directional freeze-thaw process. DOCH@P hydrogel had obvious oriented microchannel structure due to the extrusion of directional ice crystals and the chemical crosslinking during the directional freeze-thaw process, besides enhanced mechanical properties, viscoelasticity and favorable tissue adhesive strength. DOCH@P hydrogel with photothermal performance promoted the melting of the agarose in the shell of nanoparticles under NIR-activation, thus achieving NIR-responsive spermidine release behavior. NIR-activated DOCH@P hydrogel exhibited significantly robust broad-spectrum antibacterial activity and antioxidative activity. Significantly, DOCH@P hydrogel demonstrated superior capabilities in inducing directional migration and infiltration of fibroblasts through the synergistic integration of the oriented microchannels physical contact guidance and spermidine bioactivity. Based on the multi-layered spermidine-mediated immunoregulation, NIR-activated DOCH@P hydrogel ultimately drove macrophages towards anti-inflammatory M2 phenotype to alleviate excessive inflammation and remold immune homeostasis. Overall, the NIR-activated collagen-based hydrogel with oriented microchannel structure provides a promising scaffold foundation for guiding tissue regeneration through physical contact-guided cellular infiltration and anti-inflammation.
Real-time, in situ monitoring of plant physiological parameters and industrial toxic gas emissions is vital for advancing precision agriculture and ensuring environmental safety. Herein, we developed an electroactive biodegradable microneedle (PPG-MN) sensor enabling minimally invasive monitoring of interstitial glucose, ambient temperature, humidity, and environmental ammonia (NH3) gas leakage. The sensor matrix was fabricated using a polyvinyl alcohol (PVA) network interpenetrated with conductive polyaniline (PANI) and doped with phytic acid (PA), while glucose oxidase (GOx) was immobilized for specificity. The resulting microneedle array exhibited sufficient mechanical strength to penetrate the plant epidermis, establishing a stable electrode–tissue interface via hydrogel swelling. The sensor demonstrated excellent environmental friendliness, featuring a pathogen inhibition rate exceeding 97
UV-induced skin photoaging is a complex pathology driven by oxidative stress and extracellular matrix (ECM) depletion. Although recombinant human collagen (RHC) and epigallocatechin-3-gallate (EGCG) address these mechanisms, their synergy is limited by RHC’ s poor permeability and EGCG’ s instability. Here, we present a supramolecular co-assembly strategy to overcome these barriers. Validated by molecular dynamics simulations, we utilized the intrinsic proline-rich domains of RHC as anchors for EGCG to construct uniform nanospheres (< 100 nm). This architecture sterically shields EGCG, significantly enhancing stability and reducing cytotoxicity. Biologically, the nanospheres restored mitochondrial membrane potential and promoted anti-inflammatory M2 macrophage polarization. In a photoaging mouse model, the nanospheres outperformed monotherapies, effectively reversing epidermal hyperplasia and restoring the Type I/III collagen ratio. This study resolves the delivery-stability paradox of protein–polyphenol therapeutics, offering a potent strategy for regenerating photodamaged skin.
Osteoarthritis (OA), a prevalent chronic degenerative joint disorder, affects hundreds of millions of people worldwide and has become a leading cause of joint pain and functional impairment in middle-aged and elderly populations. It not only severely compromises patients’ quality of life but also imposes a significant socioeconomic burden on public health systems. Targeting key pathological processes in OA, such as inflammatory responses, chondrocyte apoptosis, and dysregulated autophagy, an injectable liposomal system named RAPA@Lipo/rhCol Ⅲ were developed in this study. This system consisted of rapamycin-loaded liposomes surface-modified with recombinant human collagen type Ⅲ (rhCol Ⅲ). It enabled sustained release of rapamycin to precisely inhibit the mTOR pathway, thereby exerting synergistic biological effects including anti-inflammation, inhibition of chondrocyte apoptosis, and promotion of autophagy. Moreover, the surface collagen modification enhanced the system’s biocompatibility and provided essential matrix microenvironment cues and bioactive signals for cartilage repair. Experimental results demonstrated that RAPA@Lipo/rhCol Ⅲ effectively scavenged reactive oxygen species in chondrocytes, promoted cell proliferation and cartilage matrix synthesis, and modulated the expression of autophagy- and inflammation-related genes, thereby synergistically achieving structural and functional restoration of OA cartilage across multiple dimensions. The integrated “disease modulation-tissue repair” strategy proposed in this study offerd a novel approach and experimental evidence for targeted therapy and functional regeneration in osteoarthritis.
Emerging carbonized polymer dots (CPDs) from natural aromatic-like lignin biopolymer have ignited the renaissance of sustainable nanoscale biomass valorization but are hindered by structural instability and functionality barriers. Herein, we report an interfacial heterostructure engineering that immobilizes lignin-based dual-emissive CPDs onto Fe, Co layered double hydroxides (LDHs), with the function of a recyclable electrode. The CPDs deliver a stable metal-ion binding behavior via rapid light-quenching with a low limit-of-detection, which are fixed into FeCo-LDH to improve the electrical conductivity, available reactive site, structural stability, and charge storage. The reconstructed FeCo-LDH@CPDs electrode outputs an ultrahigh specific capacitance of 1842.0 F g− 1 at 1 A g− 1. When assembled into a symmetrical supercapacitor (SSCs), it also achieves a superior energy density of 33.79 Wh kg− 1 at 375 W kg− 1, excellent rate performance and long-term cycling lifespan (100
