A pH-gated surface-mediated hydrogel patch for infection-responsive delivery of CRISPR-Cas9 ribonucleoprotein (RNP) complexes establishes a novel paradigm for localized, precision gene therapy and holds strong translational promise for the treatment of chronic inflammatory wounds.
Abstract
The NLRP3 inflammasome is a central driver of inflammatory tissue injury and delayed repair in bacteria-infected wounds, yet local genome editing in such lesions remains limited by nonspecific release and off-target exposure. Here, we report a pH-gated surface-mediated hydrogel patch for infection-responsive delivery of CRISPR-Cas9 ribonucleoprotein (RNP) complexes. Rather than embedding the cargo within the bulk matrix, polymer-coated NLRP3-targeting RNPs are reversibly anchored on the hydrogel surface, enabling localized presentation under physiological conditions and rapid detachment in the acidic microenvironment of Staphylococcus aureus (S. aureus)-infected wounds. In vitro studies demonstrated an NLRP3 editing efficiency of 57% in J774A.1 cells and 69% in L929 cells surpassing or matching the performance of the commercial transfection reagent Lipofectamine CRISPRMAX (50% in J774A.1; comparable in L929). In a murine full-thickness skin defect model with S. aureus infection, topical administration of the patch achieved >20% NLRP3 editing efficiency in wound tissue, accompanied by a statistically significant reduction in inflammatory cell infiltration. Consequently, this pH-responsive surface anchoring and release strategy establishes a novel paradigm for localized, precision gene therapy and holds strong translational promise for the treatment of chronic inflammatory wounds.
Methicillin-resistant Staphylococcus aureus (MRSA)-infected wounds present a significant clinical challenge due to persistent inflammation and impaired tissue regeneration. Here, we developed an IR780SS-engineered hydrogel with a hydrogen-bond-regulated network for infected wound treatment. In this system, IR780SS serves not only as a NIR photosensitizer, but also as an active component that interacts with the hydrogel matrix through hydrogen bonding, hydrophobic interactions, and π-π stacking. These interactions improve the stability and dispersion of IR780SS within the hydrogel and help preserve its photoactivity. Under 808 nm NIR irradiation, the hydrogel generates mild local hyperthermia and abundant ROS, producing antibacterial effects through combined action of PTT and PDT mechanisms. This treatment disrupts bacterial membranes and induces severe oxidative damage inside bacterial cells, leading to the near-complete elimination of drug-resistant bacteria. In a MRSA-infected wound model, rapid bacterial clearance promoted the transition from the inflammatory phase to the proliferative phase and resulted in a wound closure rate of 85.6% on day 11. Histological and immunofluorescence analyses further confirmed improved tissue repair, including enhanced re-epithelialization, angiogenic responses, and collagen remodeling, as evidenced by increased cytokeratin 14 (CK14) and smooth muscle actin (α-SMA) expression, together with more organized collagen deposition. These results suggest that integrating IR780SS into a hydrogen-bonded hydrogel not only enables effective antibacterial phototherapy but also facilitates functional wound reconstruction, providing valuable insight into the clinical development of regenerative dressings for MRSA-infected wounds.
Self-powered dressings based on triboelectric or piezoelectric systems generate alternating electric stimulation (ES) that induces M1-type macrophage polarization and exacerbates inflammation, limiting therapeutic efficacy. Here, we report a self-powered dressing integrating portable perovskite solar cells to deliver direct ES that activates anti-inflammatory M2-type macrophage polarization, thereby regulating immune responses and reshaping infected-wound microenvironments. Under optimized conditions (130 mV/mm, 30 min), solar cell-derived ES combined with antimicrobial peptide-loaded silk fibroin hydrogel (AMP@hydrogel (+ES)) efficiently eradicated pathogens by disrupting bacterial respiration, while concurrently promoting fibroblast migration, vascular endothelial tubulogenesis, and neuron differentiation. In methicillin-resistant Staphylococcus aureus-infected wounds, AMP@hydrogel (+ES) achieved 99.8% wound closure through pathogen clearance and immune regulation, accompanied by enhanced collagen deposition, re-epithelization, angiogenesis, and nerve regeneration. Transcriptomic analysis identified cytokine-cytokine receptor interaction and focal adhesion pathways as key mediators. As the first immunomodulatory self-powered dressing, AMP@hydrogel (+ES) provides a promising platform for infected-wound treatment.
Lian Duan, Yufan Bu, Peng Zhou et al.· Biomaterials· 0 citations
Gel-P@Z exhibited a slow and sustained release of Gly-POX and achieved >99% antibacterial efficacy against drug-resistant bacteria without toxicity, and RNA-seq analysis revealed that Gel-P@Z accelerated healing via upregulation of the TGF-β signaling pathway, driving fibroblast-to-myofibroblast transition and promoting tissue fibrosis.
Chuanliang Fu, Wenjing Zhang, Renyuan Wang et al.· Materials Today Bio· 0 citations
Skin defect repair remains a formidable clinical challenge, characterized by persistent infection risk, compromised angiogenesis, and dysregulated inflammatory responses. Existing hydrogel-based wound dressings fail to simultaneously address structural integrity, antimicrobial efficacy, and spatiotemporal coordination of tissue regeneration. Here, we report the development of a multifunctional bioactive hydrogel system fabricated by integrating decellularized tendon extracellular matrix (DECM) with Poly-L-lysine Methacryloyl (PLMA), and further functionalized with engineered platelet-rich plasma exosomes (PRP-Exos) loaded with siRNA targeting prolyl hydroxylase domain protein 2 (PHD2) via electroporation. The inherent cationic nature of PLMA confers robust, broad-spectrum antibacterial activity, while the sustained release of siRNA-PHD2-laden PRP-Exos achieves efficient PHD2 silencing, thereby stabilizing hypoxia-inducible factor-1α (HIF-1α) and potentiating downstream pro-angiogenic signaling. Concurrently, bioactive cues released from the DECM-based matrix promote fibroblast-to-myofibroblast differentiation and type I collagen biosynthesis, fostering a regeneration-permissive microenvironment. In both normal and diabetic murine full-thickness skin defect models, DEPL@E-SI significantly accelerated wound closure by promoting angiogenesis, inflammation resolution, and extracellular matrix remodeling. These findings establish DEPL@E-SI as a promising therapeutic platform with translational potential for skin tissue engineering and clinical wound management.
Xiangyu Du, Danmei Li, Hongpu He et al.· Bioactive Materials· 0 citations
The human skin is highly susceptible to bacterial infections and inflammation when its integrity is disrupted. Treatment of infected wounds is a big challenge in modern medicine, and rising antibiotic resistance motivates the development of antibiotic-free therapies. Here, we present a stimuli-responsive wound dressing that integrates carboxylated eggshell membrane (ESM) with electrosprayed tannic acid/iron (TAFe) particles trapped between electrospun Poly-L-lactide-caprolactone (PLCL) layers and precisely laser-structured to increase porosity and fit the wound size. The TAFe exhibits stable photothermal conversion and antioxidant activity, eradicating more than 99.5% of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), while maintaining high biocompatibility in vitro. In an infected rat model, the sandwich-like ESMmod/PLCL/TAFe dressing accelerated closure and achieved near-complete healing, with residual wound area <1% by day 14. Analysis shows that the material promotes M2-mediated reparative microenvironment, which, in consequence, suppresses TNFα and IL-6, a pro-inflammatory cytokines, and enhances angiogenesis through increased CD31 and VEGF levels. Moreover, a more organized collagen structure and less scarring were found in the wound bed. Importantly, the material is partially derived from waste, aligning with circular economy principles and reducing resource burden. The versatile composite offers an antibiotic-free strategy that disinfects, modulates inflammation, and promotes regeneration of infected wounds.
Daniel Rybak, Xingran Li, Alicja Kosik-Kozioł et al.· Small· 0 citations
Fibrosis remains a major challenge in wound repair due to the dual role of fibroblast in tissue regeneration and fibrotic deposition. Early fibroblast activation supports wound closure, whereas sustained activation during remodeling drives fibrosis, making precise temporal regulation a key challenge in advanced wound repair biomaterials design. Herein, a hierarchical hydrogel (CC-pMnO2-Vet@PNAA) was engineered to spatiotemporally regulate fibroblast behavior, achieving fibrosis suppression without compromising wound healing rate. The hydrogel matrix was constructed by reversibly reassembling irregular thermo-responsive PNAA microgels (LCST∼45°C) with caffeic acid (CA)-modified chitosan (CS-CA) via dynamic boronate ester linkages. Based on a hierarchical physical encapsulation architecture, CC-pMnO2-Vet@PNAA enabled the highly controllable, stage-specific release of polydopamine-modified MnO2 (pMnO2) and verteporfin nanoparticles (Vet NPs). During the early inflammatory phase, the hydrogel rapidly disassembled in response to pathological cues (low pH, high ROS), releasing pMnO2 and CS-CA to synergistically eliminate bacteria (>99%), neutralize oxidative stress, and restore immune homeostasis. Subsequently, in the remodeling phase, localized near-infrared (NIR) irradiation triggered microgel contraction for the on-demand release of Vet NPs, suppressing YAP signaling in fibroblasts to rebalance the mechanical microenvironment. In vivo studies in diabetic Sprague-Dawley (SD) rats model demonstrated that CC-pMnO2-Vet@PNAA established a coordinated immune-mechanical microenvironment, achieving rapid and scar-free wound healing.
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