Biomaterials Science最新文献

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.

Tumor-resident bacteria have emerged as key regulators of tumor progression, metastasis, and therapeutic resistance, yet their detection remains challenging because of their low abundance and predominantly intracellular localization. Here, we report a bacterial metabolism-activated fluorescent liposomal probe for the selective detection of intratumoral bacteria. The probe was constructed by covalently conjugating hydrophilic D-alanine, a bacterial metabolizable substrate, to a hydrophobic fluorophore, yielding an amphiphilic cationic metabolic-labeling molecule, 3-HFD. In aqueous media, 3-HFD self-assembled into fluorescence-quenched nanoaggregates through aggregation-caused quenching, thereby minimizing background fluorescence. These nanoaggregates were encapsulated into charge-reversible, membrane-fusogenic DCPA-H₂O liposomes to promote tumor accumulation and intracellular delivery. In the weakly acidic tumor microenvironment, DCPA-H₂O underwent protonation, enhancing cellular internalization and membrane fusion. Following intracellular release, the cationic probe bound with negatively charged bacteria and was metabolically incorporated into the bacterial cell wall during peptidoglycan biosynthesis, resulting in aggregate disassembly and fluorescence recovery. This metabolism-triggered fluorescence turn-on strategy enabled selective visualization of intratumoral bacteria while minimizing false-positive signals from unactivated probes. In both bacteria-associated tumor-bearing mouse models and clinical tumor specimens, the liposomal probe detected all bacteria-positive samples identified by the gold standard, demonstrating its potential for the diagnosis of bacteria-associated tumors.

Nanobodies (Nbs) are new and promising tools for a variety of applications, including their use in medicine, although their functional activity and encounter with immune cells are still not well characterized. Our goal was to study the properties of Nbs coupled with the human IgG1 antibody Fc fragment (Nb-Fc), including their interaction with antigens, Fc receptors (FcRs), and professional phagocytes: macrophages. In our research, we employed a combination of two surface-sensitive methods: spectroscopic ellipsometry (SE) and quartz crystal microbalance with dissipation (QCM-D). It enabled the quantitative investigation of interaction kinetics between human FcγRI (CD64) and immune complexes (IC) formed by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein Wuhan variant (SCoV2-S) and specific Nb-Fc, as well as the optical and mechanical properties of the formed layers. Human THP-1 macrophage cell culture was used to analyze antigen and IC induced inflammatory response, antigen presentation-related processes, as well as chemokine CCL2/CCR2 and CCL5/CCR5 axes. Our investigated Nb-Fcs had a high affinity for SCoV2-S that was comparable to that of the natural human antibody CR3022. ICs formed by Nb-Fcs also interacted with FcRs in a similar way to CR3022. One of the investigated Nb-Fcs distinguished itself by its very high affinity and formed relatively the largest ICs. Interestingly, only ICs formed by the other Nb-Fcs influenced cellular response. We found increased cell surface expression of CD83. This molecule plays a regulatory role in antigen presentation and is involved in the resolution of inflammation following infection. In addition, we did not find any increase in other investigated markers in THP-1 macrophages, including the inflammatory response. Overall, our data demonstrate that Nb-Fcs can be applied in a similar manner to conventional human antibodies, considering their properties.

Messenger RNA (mRNA)-based therapeutics hold great promise by enabling in situ expression of therapeutic proteins. The success of these therapies in vivo critically depends on the design of safe and efficient delivery systems. Polymeric micelles formed by block catiomers can encapsulate mRNA, protect it from degradation, and facilitate intracellular delivery. Polycation chain length has been proposed as a design parameter of micelles, yet how it governs stabilizing interactions to define mRNA delivery performance remains unestablished. Here, we systematically investigate this relationship using a series of poly(ethylene glycol)-poly(glycidyl-phenylalanate) (PEG-PG(Phe)) block copolymers with varying PG(Phe) chain lengths. These polymers interact with mRNA via polyion complexation and π-π stacking. Our findings revealed that the block catiomers having PG(Phe) segments with 90 units formed micelles with superior stability and enhanced endosomal escape, while micelles with shorter segments were rapidly dissociated and micelles with longer blocks showed impaired PEG shielding. Moreover, the polymer with a PG(Phe) block of 90 units achieved 2-fold higher protein expression in vivo compared to shorter or longer chain variants. These findings reveal that tuning polycation chain length with core π-π interactions is key to unlocking highly efficient mRNA delivery.

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.

Myocardial fibrosis (MF), a major driver of cardiovascular disease progression, is characterized by persistent inflammation, aberrant activation of cardiac fibroblasts, and excessive extracellular matrix (ECM) deposition. Current therapeutic strategies are constrained by limited efficacy, safety concerns, and insufficient drug accumulation and distribution within fibrotic lesions due to dense ECM barriers. Herein, we developed a lesion-targeting and ECM-penetrating nanoplatform (TIMP/Col@HH) by modifying a flexible HSA-HAase (HH) nanocapsule with a tissue inhibitor of metalloproteinases (TIMP) peptide, followed by colchicine (Col) loading. In this system, the TIMP peptide promotes accumulation in fibrotic myocardium through recognition of MMP2 overexpressed in fibrotic lesions, while the HH nanocapsule facilitates intralesional distribution within the fibrotic matrix, thereby improving local delivery of colchicine. The resulting nanoparticles exhibited favorable biocompatibility, enhanced cardiac accumulation, and improved distribution in fibrotic myocardial tissue. In vitro, TIMP/Col@HH suppressed pro-inflammatory macrophage activation, inhibited cardiac fibroblast activation and collagen deposition, and interrupted inflammation-driven fibrosis in a coculture model. In an isoproterenol-induced MF mouse model, TIMP/Col@HH exerted pronounced anti-inflammatory and anti-fibrotic effects and significantly improved cardiac function. Collectively, TIMP/Col@HH represents a promising nanotherapeutic strategy for myocardial fibrosis by integrating lesion targeting, enhanced matrix penetration, and colchicine-based intervention.

mRNA-based nucleic acid therapeutics have gained significant attention and undergone extensive clinical investigation since the FDA's approval of Spikevax and Comirnaty for the treatment of SARS-CoV-2. Lipid nanoparticles (LNPs) are currently the most advanced delivery system for delivering mRNA in vivo. However, concerns persist regarding the tolerability of their repeated use due to lipid accumulation. Over time, lipids have been optimized through the introduction of enzymatically degradable ester linkers. Yet, this modification alone does not fully address lipid clearance from the body. To mitigate these concerns, we have designed a library of novel ionizable lipids that incorporates two nitrogen atoms within the lipid backbone. We hypothesize that the LNPs with these lipids can be potentially administered at lower dosages while maintaining the same payload delivery and translation efficiency. In this study, we identified five lead LNPs that exhibited remarkable transfection efficiency without cytotoxic effects in vitro. We further optimized the LNP formulations by incorporating various cholesterol analogs to fine-tune translation performance. Upon analyzing the endocytic and intracellular pathways of the lead LNPs, we found that multiple pathways were involved in delivering the payload to the cell. This set of novel lipids holds great promise for mRNA delivery and warrants further investigation.

The complex microenvironment of wounds, characterized by hyperglycemia and bacterial infections, significantly impedes the healing process, thereby necessitating the development of highly effective bio-composite wound dressings. Herein, a recombinant glucose oxidase (GOD)-based cascade catalytic MIL@GOD was fabricated and encapsulated within a carbohydrate-rich dual-network hydrogel matrix composed of carboxyethyl chitosan (CECS) and oxidized sodium alginate (OSA) and mechanically reinforcing oxidized bacterial cellulose nanocrystals (OxBCNC) to construct a multi-responsive and cascade-amplified composite hydrogel. The hydrogel demonstrated excellent mechanical properties and multiple responsiveness, including cascade catalytic activity, antibacterial activity, anti-biofilm activity, and desirable biocompatibility. The evaluation of the wound healing effects of the resultant composite hydrogels revealed that these hydrogel dressings enhanced the healing process in full-thickness skin defect models. The desirable wound healing effects may be attributed to the ability of the hydrogel to consume glucose at the wound site and self-supply H₂O₂ for ROS production, thereby reducing glucose concentrations while concurrently decreasing bacterial infections and inflammatory responses. Additionally, the composite hydrogel functions as a supportive dressing to facilitate collagen deposition and angiogenesis, thereby enhancing the wound healing process. These results collectively indicate that the composite hydrogel successfully constructs a GOD-mediated multi-responsive cascade platform as an antibacterial wound dressing, demonstrating significant potential for the treatment of infected wounds.

Dendrimers are highly branched nanoscale macromolecules with precisely tunable architectures that have emerged as transformative tools in cancer research. Their unique properties, such as high drug-loading capacity, multivalency, and surface tailoring ability, enable innovative applications in drug delivery, gene therapy, diagnostics, and immunotherapy. This review critically evaluates dendrimer performance against conventional nanocarriers, introduces a novel dendrimer-TME interaction matrix that classifies functions along cytotoxicity and microenvironment-modulation axes, and proposes actionable clinical-translation strategies. We critically evaluate their advantages over conventional nanocarriers, address challenges such as toxicity and scalability, and propose novel directions. Moreover, we identify persistent gaps in toxicity and scalability, emphasize stimuli-responsive systems, theranostics, and immune modulation, and outline how these advances could accelerate precision oncology while realistically discussing barriers to bedside translation.

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, functional anti-angiogenic therapy in vitro, and preliminary in vivo topical corneal transfection.