Dry eye disease is a chronic inflammatory disorder of the ocular surface in which tear film instability and hyperosmolarity perpetuate a self-sustaining cycle of epithelial damage and inflammation, yet the...
Zwitterionic hydrogel coatings comprise three-dimensional networks of zwitterionic polymers that bear balanced anionic and cationic groups. These coatings exhibit superior hydration capacity, high drug-loading efficiency, excellent biocompatibility, and remarkable salt...
A compact sequence-defined repetitive peptide, (CYR)3, was designed for ocular plasmid DNA delivery. Integrating cationic, aromatic, and cysteine residues, (CYR)3 condenses plasmids into near-neutral biocompatible nanoparticles, achieving efficient intracellular transport,...
PEG has been commonly considered safe and is widely used in pharmaceutical and personal care products. Concerns about its safety arised in relation to studies demonstrating its accumulation in some organs of animals treated with very high PEG dosages (e.g., 200 mg per kg per week for up to 12 weeks). Although these dosages are substantially higher (200-100 000 times) than those of PEG-containing drugs, the concerns might still be valid for chronic therapies if the polymer is not cleared after the accumulation. In this study, in addition to investigate the phenomena of PEG accumulation/elimination and its effects on full blood count, plasma biochemistry and behavioral performance of treated animals, we also studied new hydrolysable PEGs (HyPEGs) for reducing PEG accumulation. HyPEGs contain a cleavable linker that, upon in vivo hydrolysis, lowers by half the size of the polymer. We here evaluated the in vitro effect of 20- and 40 kDa conventional PEGs on macrophages' phenotype in THP1 cells, and the potential in vivo toxicity, biodistribution, and vacuolation in liver, kidneys, spleen, choroid plexus, heart, and lungs of a small library of 20- and 40 kDa-conventional and hydrolysable PEGs, with both linear and branched structures, administered twice weekly for 12 weeks at the high dosage of 200 mg per kg per week followed by an 8-week washout period (no PEG administration). We demonstrated that PEG internalization by macrophages resulted in molecular weight-dependent cellular responses. In vivo, all PEGs accumulated in the liver, spleen, kidneys, and choroid plexus, and in general accumulation of HyPEGs was less evident. The 8-week washout period allowed for the clearance of most of the accumulated PEGs in all organs except for the kidneys, likely because the kidneys are the terminal organs for PEG elimination. Overall, all PEGs did not show any hematotoxicity by analyzing biochemical- and hematological-parameters. Cytoplasmic PEG-negative vacuoles were present in the choroid plexus, suggesting adaptive cellular responses, but no signs of neurotoxicity were observed. Our results indicate that, although the different PEGs elicited distinct macrophage responses in vitro, all hydrolysable PEGs showed limited tissue accumulation in vivo without signs of toxicity, highlighting their safety.
Osteosarcoma (OS) is one of the most prevalent primary malignant bone tumours, with a poor prognosis in metastatic cases due to its aggressive nature, high metastatic potential and frequent resistance to conventional therapies. A most crucial approach for investigating drug resistance, metastasis and tumour progression is the recapitulation of the complex tumour microenvironment (TME), which is limited in traditional 2D cell cultures. Sophisticated 3D in vitro models developed via recent advances in materials sciences and cancer biology including cell spheroids, organoids and scaffold-based and hydrogel-based systems more precisely mimic the tumour microenvironment, thus offering deeper insights into tumour biology and therapeutic responses. Hydrogels inherently provide biomimetic cues that promote cell adhesion, proliferation & differentiation, particularly their porous and hydrated characteristics closely replicate the native extracellular matrix. Most importantly, hydrogels can be used for OS therapy both as a depot for therapeutic agents and scaffolds for bone tissue regeneration. This approach could be particularly promising for adjuvant therapy of tumours, as it provides options for both treatment and tissue regeneration. This review explores the emerging innovations in hydrogel-based OS in vitro models, their fabrication methods and applications in drug screening and adjuvant therapies. Furthermore, the challenges in clinical translation and advancing OS models for clinical applications are discussed. Finally, the challenges and future perspectives are outlined by emphasizing the need for multidisciplinary collaboration to advance OS research and therapy.
Severe inflammation and infections are major contributors to wound chronicity. Although various wound dressings have been engineered to deliver therapeutics locally, the lack of patient personalization is still a limiting factor. In this endeavor, this work aims to establish an adaptable therapeutic strategy by combining stimuli-responsive materials and 3D bioprinting for the prospective fabrication of shape-personalized patches capable of tuning payload release in response to the alkalinity of infected wound exudates. First, a -COOH-bearing amphiphilic poly(ether urethane) was synthesized and used to formulate thermo-/alkaline-pH-responsive hydrogels, while human recombinant lactoferrin (hrLF) was selected for its naturally derived therapeutic properties. Then, the hrLF-loaded hydrogel thermo-responsiveness was rheologically assessed, while the hrLF suitability for the biologically aggressive environment of chronic wounds was evaluated through UV/Vis spectroscopy and a colorimetric assay. Moreover, a finely tuned drug release was observed in response to pH via a non-Fickian diffusion mechanism. Furthermore, in in vitro studies on simplified inflamed wounds, hrLF promoted human dermal fibroblast proliferation (increased DNA content), exerted anti-inflammatory effects (reduced expression of TNF-α, IL-1β and IL-6), and exhibited bacteriostatic activity against Staphylococcus aureus. Finally, the hrLF-loaded hydrogel showed promising processability as a biomaterial ink. Overall, the engineered system showed strong adaptation to the dynamic wound environment.
The delivery of therapeutic short interfering RNA (siRNA) is hindered by biological barriers such as rapid degradation and poor cellular uptake. This study investigates peptide-based nanogels (NGs) as potential delivery platforms using three N-capped tripeptides, 2NapKFF, 2NapFKF, and 2NapFFK, designed to load siRNA via electrostatic interactions. The NGs were formulated through a "top-down approach" from pH-triggered hydrogels (HGs) and stabilized by surfactants. Biophysical characterization revealed that while all tripeptides achieved ∼99% siRNA encapsulation, the position of the lysine residue significantly influenced the stability and mechanical properties of the network. The 2NapFKF system emerged as the most suitable candidate, maintaining a size (∼200 nm) compatible with parenteral administration. Biological assays on Human Embryonic Kidney (HEK293) cells confirmed biocompatibility and cytoplasmic internalization through endocytic pathways. Furthermore, the treated cells maintained normal mitotic activity, indicating no impairment of cell proliferation. These findings demonstrate that lysine-modified tripeptide NGs are safe and effective tools for gene-silencing applications.
Immunotherapy has shown enormous promise for cancer treatment, yet its efficacy is often hindered by the highly immunosuppressive tumor microenvironment (TME). Here, we developed a pH-responsive and cRGD-modified multifunctional liposomal system (FP2@PSLR) to co-deliver an immunogenic cytotoxic peptide (FR) and the PI3Kγ inhibitor IPI549 for coordinated TME remodeling. FR induces immunogenic cell death while exerting direct cytolytic activity, whereas IPI549 promotes macrophage repolarization toward the pro-inflammatory M1-like phenotype, enabling synergistic relief of immune suppression. FP2@PSLR, constructed from acid-sensitive lipids via reverse-phase evaporation, exhibited a uniform size (∼156 nm), high encapsulation efficiencies, excellent physiological stability, and rapid drug release under mildly acidic conditions. In vitro, the liposomes showed good biocompatibility, reduced hemolysis, effective immunogenic cell death induction, dendritic cell activation, and macrophage repolarization. In a 4T1 tumor model, FP2@PSLR demonstrated prolonged circulation, strong αvβ3 integrin-mediated tumor targeting, and clear NIR-II fluorescence for real-time tracking. Treatment resulted in significant TME reprogramming, including enhanced CD8+ T-cell infiltration, increased immune memory formation, and potent antitumor effects without systemic toxicity. These findings highlight FP2@PSLR as a rationally engineered nanoplatform capable of enhancing antitumor immunity through multi-pathway modulation of the immunosuppressive TME.
Engineering osteochondral scaffolds with continuous gradients remains a central challenge in regenerative medicine. Here, we present a one-step melt electrowriting (MEW) strategy to encode quasi-continuous compositional and structural gradients in poly(ε-caprolactone) (PCL) scaffolds. By sequentially loading nanohydroxyapatite (nHA)-laden PCL melts, a predefined mineral gradient is preserved during printing, yielding a continuous decrease in nHA content across the scaffold thickness. This gradient intrinsically drives a concomitant reduction in fiber diameter, thereby recapitulating the native transition from subchondral bone to cartilage. A porous TGF-β1-loaded hydrogel coating is further introduced to provide spatially relevant chondrogenic cues without compromising pore interconnectivity. The resulting scaffolds exhibit graded composition, structure, and mechanical properties, enabling coordinated osteogenic and chondrogenic differentiation of human bone marrow mesenchymal stem cells in vitro and promoting integrated osteochondral repair in vivo. This work establishes a generalizable MEW-based platform for single-step gradient encoding and offers a biomimetic design strategy for complex tissue interfaces.
Chronic diabetic wounds remain a major clinical challenge owing to persistent bacterial infection, prolonged inflammation, excessive exudation, and impaired tissue regeneration. Herein, an injectable thermosensitive hydrogel was developed by integrating N-[(2-hydroxy-3-trimethylammonium)propyl] chitosan chloride with aldehyde-functionalized Pluronic F127 for epidermal growth factor (EGF) delivery and diabetic wound repair. The hydrogel forms a dual-crosslinked network through temperature-induced micellization and dynamic Schiff base bonding, exhibiting rapid gelation under physiological conditions, shear-thinning behavior, and self-healing properties. In vitro, the hydrogel provides a sustained release profile of EGF exhibiting effective antibacterial activity against Gram-positive S. aureus. In vivo studies in streptozotocin-induced diabetic rats demonstrate significantly accelerated wound healing, achieving 83% wound closure within 14 days compared to 45% in the control group, along with enhanced tissue regeneration characteristics, including improved collagen deposition. This multifunctional hydrogel provides a promising strategy for diabetic wound management by integrating antibacterial potential and tissue regeneration.
Complex maxillofacial bone anatomy compromises the efficacy of local anesthetics. This study develops an ultrasound (US)/reactive oxygen species (ROS) cascade-responsive polylactic-coglycolic acid (PLGA) nanoparticle system for enhanced dental infiltration anesthesia and perioperative pain management. The nanoparticles, which were surface-modified with alendronate (ALN) via an ROS-cleavable thioketal (TK) linker and coloaded with bupivacaine (BUPI) and perfluorohexane (PFH), enabled enhanced bone targeting and penetration. Under US stimulation, PFH undergoes a liquid-gas phase transition, generating ROS that cleave TK linkers, switching the system from a "bone-targeting" to a "bone-penetration" state. This cascade mechanism facilitates deep tissue penetration of local anesthetics for enhanced anesthesia while enabling a dual-phase release profile: rapid US-triggered BUPI release for intraoperative analgesia and sustained diffusion for postoperative pain management. In rat models of tooth extraction and pulp injury, the system demonstrated superior efficacy over conventional BUPI, significantly increasing drug concentrations in the mandibular bone and improving pain-related outcomes. Biocompatibility was confirmed via histology and serum biomarkers. By overcoming maxillofacial bone barriers and enabling responsive, biphasic drug release, this platform represents a promising strategy to address the limitations of current local anesthetics in dentistry, reducing local anesthesia failure rates and improving perioperative pain control.
Vital pulp therapy for caries-induced pulpitis is limited by the acidic, oxidative and inflammatory microenvironment. Here, we present zinc-iron nanozymes (ZFNs) designed for sequential infection control and inflammation resolution. ZFNs exhibit pH-dependent multi-enzymatic activities: optimal peroxidase-like activity at pH 5.0 (mimicking the Streptococcus mutans microenvironment) and dominant catalase- and superoxide dismutase-like activities at neutral pH. Under acidic conditions, ZFNs convert H2O2 into hydroxyl radicals, achieving >99% bactericidal efficacy against S. mutans and suppressing bacterial acid production. At neutral pH, ZFNs scavenge reactive oxygen species, reduce intracellular reactive oxygen species levels in inflamed dental pulp stem cells, and downregulate pro-inflammatory cytokines (TNF-α, IL-6, IL-1β, and IL-8). They also partially restore osteogenic/odontogenic differentiation markers (ALP, RUNX2, and DSPP). In a rat pulpitis model, direct pulp capping with ZFNs substantially decreased pulpal necrosis and inflammatory infiltration on day 5 and promoted tissue repair, showing early anti-inflammatory effects comparable to or better than the commonly used clinical material iRoot BP. These findings suggest that this nanozyme platform with pH-dependent multi-enzymatic activities can support sequential infection control and inflammation resolution, offering a potential strategy for vital pulp therapy.
Cardiovascular diseases continue to exhibit high global morbidity and mortality rates, driving urgent demand for the development of small-diameter (diameter < 6 mm) vascular grafts. Current small-diameter vascular grafts exhibit low patency rates in vascular reconstruction due to incomplete endothelial coverage. The design of vascular grafts with spontaneous endothelialization is critically needed. Herein, we developed an on-demand ROS-responsive polycaprolactone (PCL) graft modified with puerarin (PUE) and hyaluronic acid (HA) by electrospinning. In this study, PCL mimicked the structure of native blood vessels, and PUE-HA encouraged the antioxidation and endothelialization of vascular grafts with improved biocompatibility. The PUE-HA-PCL graft could promote the adhesion and proliferation of endothelial cells (ECs) and facilitate the process of tissue regeneration. Moreover, the grafts remained completely unobstructed with well-organized elastin fibers for 3 months after implantation. Taken together, the results effectively demonstrate that PUE-HA-PCL will be a promising functional small-diameter vascular graft with spontaneous endothelialization.
Tendon-bone interface (TBI) injuries, typified by rotator cuff tears, are common musculoskeletal disorders. Their intrinsic healing capacity is limited by pathological conditions such as local hypoxia, oxidative stress, and secondary fatty infiltration, which prevent spontaneous restoration of the native four-zone gradient architecture. As a result, functional tissue is often replaced by fibrovascular scar tissue with inferior mechanical properties. Because surgical repair alone cannot precisely recreate this complex interface, highly biomimetic tissue-engineered regenerative strategies have emerged as a promising alternative. Beginning with the anatomy of the rotator cuff and the key challenges in treating rotator cuff injuries, this review summarizes the spatiotemporal complexity, physiological vulnerability, and rehabilitation challenges of the TBI. It further discusses the structural composition, fabrication methods, mechanisms of action, and clinical applications of tissue-engineered strategies for TBI regeneration. These approaches use scaffolds based on hydrogels, decellularized matrices, polymers, collagen, and nanoparticles, which can be functionally engineered through graded architectures, aligned structures, mineralization cues, and tailored interfacial properties. In parallel, active components such as stem cells, exosomes, and bioactive factors can be incorporated to recreate a three-dimensional microenvironment that supports tissue regeneration, attenuates inflammation, regulates bone metabolic homeostasis, and promotes vascular regeneration. Although substantial progress has been made in tissue-engineered repair of rotator cuff injuries, future studies should place greater emphasis on digitally enabled and coordinated scaffold design, more robust safety assessment, and quantitative evaluation of therapeutic efficacy. Mechanistic studies and translational research will also be essential to bridge the gap between basic research and clinical application.
Interleukin-12 (IL-12) potently activates antitumor immune responses and compensates for the challenge of insufficient T cell activation and infiltration faced in immune checkpoint therapy. However, its clinical application is limited by severe systemic toxicity and the upregulation of PD-L1 on tumor cells during treatment. Here, we developed iLANpTyr-IL-12, a lipid-assisted nanoparticle system loaded with tyrosinase (Tyr) promoter-driven IL-12 plasmids, designed to achieve specific and sustained IL-12 expression exclusively in melanoma cells. The secreted IL-12 promoted dendritic cell maturation, T cell activation and proliferation, and IFN-γ secretion. Notably, iLANpTyr-IL-12 treatment upregulated PD-L1 expression on tumor cells, suggesting a negative feedback loop that supports the rationale for combination with anti-PD-L1 (αPD-L1). In a subcutaneous B16-F10 melanoma model, iLANpTyr-IL-12 monotherapy significantly enhanced tumor suppression and increased intratumoral infiltration of T cells and NKT cells, along with a decreased M2/M1 macrophage ratio. When combined with αPD-L1, it produced an enhanced antitumor effect, achieved a tumor growth inhibition rate of 83% and further augmented intratumoral CD8+ T cell infiltration. Additionally, no significant systemic toxicity or organ damage was observed. Collectively, these findings demonstrate that iLANpTyr-IL-12 enables tumor-specific IL-12 expression and, when combined with αPD-L1, provides a promising cytokine-immune checkpoint combination immunotherapy with reduced off-target toxicity.
Bioactive coatings are designed to regulate interfacial interactions between biomaterials and host tissues, and represent an important strategy for improving the anti-infective capacity, immunomodulation, and tissue integration of biomaterials. However, current bioactive coatings still face challenges in precise molecular design, long-term interfacial retention, and functional maintenance under complex physiological conditions. Self-assembling peptides (SAPs), owing to their sequence programmability, supramolecular assembly capability, modular functional integration, and environmental responsiveness, provide a versatile platform for constructing designable and controllable bioactive coatings. This review systematically summarizes the unique advantages of SAPs in bioactive coating construction and discusses their design logic from three key dimensions: peptide sequence design, assembly behavior, and interfacial presentation. Recent advances in SAP-based coatings are further reviewed in the contexts of anti-infection and mineralization protection, inflammatory microenvironment modulation, tissue-specific integration, and regenerative repair. Finally, the key issues limiting their precise design and clinical translation are analyzed, including interfacial retention under physiological conditions, the balance between assembly stability and functional motif exposure, and the maintenance of durable coating functions in complex interfacial environments. Overall, SAP-based coatings are evolving from passive surface-modification materials into programmable, functionally tunable, and mechanistically interpretable biointerfaces, offering new perspectives for the development of next-generation biomedical materials.
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. To simultaneously address multiple pathological barriers, an intelligent composite nanoplatform was designed and constructed in this study, integrating near-infrared (NIR) photothermal therapy, reactive oxygen species (ROS) scavenging, antimicrobial activity, and immunomodulation. A mesoporous polydopamine (MPDA) core was loaded with chlorogenic acid (CGA), a natural antioxidant, and further coated with a copper-zinc bimetallic organic framework (Cu/Zn-MOF) to fabricate Cu/Zn-MOF@CGA@MPDA NPs, exhibiting pH-responsive dissociation in the acidic infected wound microenvironment. Under 808 nm near-infrared irradiation, the fabricated NPs showed excellent photothermal performance, efficiently eliminating bacteria and biofilms in vitro. They also scavenged ROS to relieve oxidative damage and promoted macrophage polarization from the pro-inflammatory M1 to pro-healing M2 phenotype. In a diabetic rat model of infected full-thickness skin wounds, the nanoplatform achieved antibacterial and anti-inflammatory effects simultaneously. Such synergistic functions promoted collagen deposition and re-epithelialization, thereby accelerating diabetic wound healing. Histological and hematological tests verified its good biocompatibility and biosafety. This work developed a synergistic single-platform strategy for precise regulation of diabetic wound microenvironments, providing a promising therapeutic alternative for refractory diabetic wound treatment.
Electrospun nanofiber mats are a versatile delivery system that can be applied locally at a target site, making them attractive for localized gene delivery. Although some studies reported electrospinning of nucleic acids, polyethylene oxide (PEO) was primarily used as a co-spinnable additive rather than as a standalone carrier in previous studies. In this study, PEO and gelatin nanofiber mats were prepared via blend and coaxial electrospinning to encapsulate pDNA and mRNA polyplexes prepared with a commercial transfection reagent. Notably, mRNA complexes were directly encapsulated within electrospun nanofibers through blend electrospinning, an approach not previously reported for mRNA delivery from fiber matrices. The results showed that PEO fiber mats exhibit higher encapsulation efficiency (∼60% for pDNA), transfection performance (∼75% of the free-complex level), and maintenance of polyplex integrity than gelatin, blend, and coaxial fibers for both types of nucleic acids. Stability studies over time have shown that encapsulation within electrospun fibers significantly increased the functional lifetimes of both polyplexes compared with non-electrospun (free) polyplexes. Free pDNA polyplexes lost ∼95% of their activity within 24 h, whereas PEO fiber-encapsulated pDNA retained most of its activity, losing only ∼35% over the same period. Cytotoxicity analysis showed that all fiber mats maintained cell viability above 70% at low-to-moderate electrospinning polymer amounts. It was thus shown that PEO electrospun nanofibers can serve as efficient standalone carriers for nucleic acid delivery, with polymer selection influencing encapsulation, transfection, and stability.
Atopic dermatitis is a serious, chronic inflammatory skin disease that can currently only be treated symptomatically. The rise in extracellular Ca2+ ions by mast cells and platelets, which acts as a death signal for neuronal cells, plays a crucial role in the pathogenesis of the disease. Both cell types produce the neurotransmitters histamine and serotonin and express the N-methyl-D-aspartate (NMDA) receptor on their surface. Here, we show that the physiological inorganic polymer polyphosphate (Na-polyP; when administered as the sodium salt), which is stored and released by platelets, can suppress the adverse effects in atopic dermatitis due to its unique ability to bind Ca2+ by coacervate formation. This eliminates the Ca2+ burst occurring in neural tissue damage by exchanging Na+ for Ca2+ ions. It is shown that the energy-rich Na-polyP, with a physiological chain length of approximately 50 phosphate residues, enhances the serotonin-induced neurite outgrowth in neuronal PC12 cells, even in the absence of the neurotransmitter and additional Ca2+ ions. In rat primary neuronal cells, Na-polyP completely prevented the histamine-caused apoptotic cell death. Based on the results of experiments with the indicator Fura 2-AM, which demonstrated an abolition of the histamine- and glutamate-induced rise in intracellular Ca2+ levels in neurons after addition of Na-polyP, we conclude that the neuroprotective effect of Na-polyP is due to the formation of polyP coacervate through Na+/Ca2+ exchange. Furthermore, it was found that Na-polyP enhances collagen fibrillogenesis, which is impaired in atopic dermatitis, as demonstrated by immunostaining and RT-qPCR experiments using human endothelial cells (HUVEC). The role of disease-relevant metalloproteinases induced by polyP was demonstrated in experiments with the inhibitor quercetin, using CD80 as a marker for pro-inflammatory M1 macrophages. Finally, studies in patients showed that Na-polyP embedded in a hydrogel can alleviate and heal atopic dermatitis lesions, indicating the potential of Na-polyP as a clinically applicable drug for treating the disease.
Therapeutic resistance in breast cancer, driven by tumor-intrinsic adaptive mechanisms and microenvironmental survival cues, remains a critical barrier to curative treatment. To address this dual challenge, we developed a redox-responsive polymeric micelle system (TPSP) functionalized with telmisartan for simultaneous targeting of angiotensin II type 1 receptor-overexpressing tumor cells and cancer-associated fibroblasts (CAFs). This platform co-encapsulates doxorubicin (DOX), a classic topoisomerase IIα (Topo IIα) poison, and aconitine linoleate (L29), a novel catalytic Topo IIα inhibitor with a distinct mechanism of action compared with conventional agents. The TPSP micelles exhibit dual therapeutic synergism: (1) L29 disrupts DNA replication through G1/S cell cycle arrest via Topo IIα catalytic inhibition, complementing DOX's DNA double-strand break induction to counter acquired resistance, and (2) telmisartan-mediated CAF depletion disrupts stromal-mediated drug resistance by eliminating metabolic symbiosis and biomechanical barriers. In vivo evaluations across resistant breast cancer models revealed superior tumor growth inhibition (>72%) with CAF ablation. This combinatorial nanomedicine strategy pioneers a paradigm shift in overcoming multidrug resistance by concurrently targeting tumor plasticity and microenvironmental protection, providing a clinically translatable blueprint for treatment-refractory malignancies.
