ACS Applied Bio Materials最新文献

We present a strategy for the irreversible and oriented immobilization of native antibodies (Abs) onto magnetic nanoparticles (MNPs) by integrating Ni²⁺-NTA chelation with diazirine (Dia)-mediated photo-crosslinking. MNPs were co-functionalized with nitrilotriacetic acid (NTA) and photoreactive Dia-2 to create a mixed monolayer NTA/Dia-2@MNPs that selectively binds the His-rich Fc domain of unmodified Abs. Short UV exposure activates Dia-2, generating reactive carbenes that covalently anchor proximal residues and permanently lock the Ab in an oriented configuration. This dual-mode immobilization preserves Fab accessibility, enhances binding performance, and prevents Ab dissociation during stringent washing. We validated the platform using two cancer therapy Abs (trastuzumab and cetuximab) and one cancer biomarker (anti-serum amyloid A, anti-SAA) in cancer cells and human serum. Anti-SAA MNPs fabricated by the NTA-Ni²⁺ method showed a 1.5-fold increase in antigen binding in the serum sample compared to the boronate affinity-based method and a significant (22-fold) improvement over random immobilization. Cetuximab-functionalized oriented MNPs by the current immobilization strategy achieved a 4.7-6-fold enhancement in EGFR pulldown efficiency from human embryonic kidney (HEK293T) and non-small cell lung cancer (NSCLC) models, compared to randomly immobilized controls. Notably, the oriented MNPs enabled co-purification of markedly high interactome coverage of >1000 proteins and differential abundance of downstream proteins. Importantly, this platform requires no prior Ab modification and is compatible with full-length native Abs and stable in complex biological samples (cell or serum). By combining chelation-guided orientation with photoinduced covalent fixation, this strategy addresses key challenges in Ab surface engineering and offers a robust, versatile solution for applications in immunoprecipitation, proteomics, and biomarker discovery.

Skin barrier dysfunction and oxidative stress caused by aging and UV exposure often result in pigmentation and photoaging, necessitating safe and effective topical delivery systems. However, co-delivering hydrophilic and lipophilic bioactives remains challenging due to their divergent solubility and stability profiles. To address this, we developed a W/O/W multiple emulsion stabilized by biopolymer-based nanoparticles for the synergistic transdermal delivery of arbutin and resveratrol. Phosphorylated zein, an amphiphilic plant protein, was combined with carboxymethyl chitosan to form composite colloidal particles that encapsulated resveratrol and acted as natural Pickering stabilizers at the O/W interface. This system successfully encapsulated arbutin in the internal aqueous phase and resveratrol in the zein-based composite colloidal particles. The resulting emulsions exhibited high arbutin encapsulation efficiency (up to 94.76%), strong antioxidant activity (DPPH scavenging >82% at 45 mg/mL), and sustained tyrosinase inhibition (>75% after 14 days). Skin permeation studies revealed enhanced transdermal delivery, with fluorescent probe penetration depth reaching ∼4861 μm. This work demonstrates the potential of zein-based biopolymer systems in building multifunctional emulsions for safe, efficient, and synergistic delivery of active ingredients in skincare applications.

Melanoma is a malignant type of skin cancer that originates from pigment-producing cells called melanocytes. Alongside its aggressive trajectory, it is characterized by metastasis. The lack of targeting ability and high toxicity in traditional chemotherapy, along with issues such as the dermal barrier and patient compliance, necessitate local and synergistic treatment approaches. Patches that are part of transdermal drug delivery systems and use hydrogel microneedles to deliver drugs noninvasively, locally, and synergistically, are a recently emerging treatment alternative. In this study, we designed a microneedle patch composed of microneedles produced by 3D digital light processing, which were made of sodium alginate and GelMA. The GelMA support base contained an anticancer drug (5-FU) and graphene oxide quantum dots dispersed in a polyvinylpyrrolidone matrix. Quantum dots conferred photothermal activity under near-infrared (808 nm) light, whereas 5-FU provided the chemotherapy effect. The microneedle had a height of 917.6 ± 47 μm, tip radius of 26.9 ± 0.4 μm, 5-FU burst release of 63 ± 0.665% within the first hour, and 100% release within 96 h. It exhibited photothermal properties, reaching 46.3 °C within 5 min under the effect of NIR. The patch substantially reduced the viability of cancerous A375 cells, exhibiting suitable mechanical properties for skin penetration, as well as swelling and degradation properties for drug release. The findings suggest that the minimally invasive microneedle platform, which enhances patient compliance, could be a promising solution for melanoma treatment through the synergistic use of chemotherapy and photothermal therapy.

Liquid-liquid phase separation (LLPS) compartmentalizes biological systems into dynamic, membraneless condensates that regulate diverse cellular functions. Although protein and RNA-mediated LLPS have dominated research, DNA increasingly emerges as an active driver of phase separation rather than a passive structural scaffold. DNA-driven condensates orchestrate critical nuclear processes, from chromatin organization and transcriptional regulation to genome stability and innate immune responses. Yet LLPS principles extend beyond biology: programmable DNA nanostructures now enable synthetic droplets and hydrogels with tunable mechanical properties, opening pathways to biomaterials, diagnostics, and synthetic cells. Here we synthesize current understanding of DNA-mediated LLPS across biological and synthetic domains, emphasizing five underappreciated topics: (1) DNA's active driving role in LLPS through charge and topology; (2) reversible DNA aggregation and aggregate-to-condensate transitions, distinct from irreversible protein misfolding; (3) non-Fickian transport mechanisms including ballistic wave diffusion triggered by molecular recognition; (4) single-molecule mechanical characterization revealing state-dependent material properties; and (5) the multiscale complexity of cellular DNA condensation shaped by topological constraints and hierarchical organization. We highlight emerging single-molecule technologies, optical tweezers, and scanning probe microscopy that directly measure condensate mechanics and state transitions with unprecedented resolution. This integrated perspective bridges fundamental biophysics of natural DNA condensates with rational engineering principles for programmable synthetic systems, providing a blueprint for therapeutic and biotechnological applications.

Conventional cancer therapies have been limited by severe side effects and low treatment specificity, leading to reduced survival rates and a reduced quality of life. In particular, the heterogeneity of the reductive conditions, such as high glutathione (GSH) and H₂O₂ levels and acquired drug resistance, remains a major obstacle that traditional drug delivery systems (DDS) struggle to overcome. While GSH is especially essential for maintaining cellular redox, its upregulation in cancers facilitates tumor survival and therapeutics, making it a pivotal target. Therefore, the development of multimodal therapeutic platforms capable of reductive condition-responsive activation, multimechanistic action, and selective cellular targeting is in high demand. In this study, we developed a redox-responsive multimodal nanoplatform (Cu-pSiDox-Glu) based on porous silicon nanoparticles (pSiNPs), which incorporate a copper(Cu)-silicate surface layer, the chemotherapeutic agent doxorubicin (Dox), and a glucosamine (Glu) moiety for tumor targeting. The system was designed to generate reactive oxygen species (ROS) under GSH/H₂O₂-rich conditions and to accumulate selectively in tumor cells via glucose transporter (GLUT)-mediated uptake. Cu-pSiDox-Glu showed enhanced copper-induced ROS generation via a Fenton-like reaction. Cellular analysis revealed selective uptake and potent cytotoxicity in Huh-7 hepatocellular carcinoma cells while maintaining low toxicity in normal HEK293 cells. These findings suggest that Cu-pSiDox-Glu is a promising multimodal nanoplatform for precise and effective cancer therapy through reductive condition-responsive ROS production and chemotherapeutic delivery.

Four-dimensional (4D) printing represents a paradigm shift in additive manufacturing, enabling the creation of dynamic, stimuli-responsive structures that can change shape or function over time. This study introduces a significant advancement in this field by developing 4D-printed responsive cellulosic composite (RCC) strips consisting of varying ratios of AFFINISOL (AFF, a hydroxypropyl methylcellulose derivative) and thermoplastic starch (TPS) using fused filament fabrication (FFF) technology. Further, 4D-printed RCC strips were characterized for thermal properties, which revealed glass transition temperature (T_g) between 97 and 104 °C as well as fluid uptake of approximately 70% in 4 h. Subsequent investigation, focused on evaluating the solvent-responsive shape-memory behavior of RCC strips using water as a solvent, highlighted the maximum shape recovery index (SRI), i.e., 0.98 within 105 min. Next, to demonstrate the responsive nature of the RCC strips, the shape-memory behavior was evaluated in solvents with varying polarities. The results revealed a clear interplay between solvent polarity and the rate of shape recovery of RCC strips. The strips demonstrated exceptional recovery in water; however, their recovery was severely hindered in ethanol (EtOH) with an SRI of 0.14 within 105 min and was completely absent in n-hexane. We attribute this polarity-driven response to RCC matrix-solvent interactions and the differential diffusion rate of solvents within the RCC matrix, validated using various hydroalcoholic solutions. These findings establish an avenue for innovative solvent-responsive shape-memory behavior of RCC and underscore the future potential of FFF-mediated 4D-printed RCC strips for biomedical, tissue engineering, soft robotics, and reconfigurable systems applications.

Given the rising global prevalence of hyperuricemia (HUA) cases and the side effects associated with current therapeutic or management strategies, there is a growing need for safe, stable, and nontoxic alternative treatments. Using taraxacum as a carbon source, this study synthesized taraxacum-derived carbon dots (T.CDs) that exhibit significant antioxidant and anti-inflammatory activities. The structure and antioxidant capacity of T.CDs were thoroughly characterized. In vitro cell experiments and in vivo assays using Caenorhabditis elegans demonstrated that T.CDs alleviated HUA by scavenging free radicals and reducing oxidative stress. Furthermore, in HK-2 cells, T.CDs were found to upregulate ABCG2 expression and downregulate URAT1, providing an additional mechanism for their anti-HUA effect. Animal studies confirmed that T.CDs not only mitigated HUA but also repaired renal injury by modulating renal Fe³⁺/Fe²⁺ levels. Additionally, T.CDs modulated the gut microbiota composition and restored short-chain fatty acid production. These findings highlight the significant potential of T.CDs as nanotherapeutics for HUA management.

Cancer, as a global health crisis, continues to threaten human life and health. Chemotherapy occupies a central position in cancer treatment, but conventional chemotherapeutic agents have some limitations, such as low solubility, lack of specific targeting, insufficient bioavailability and high toxicity to normal tissues. However, the use of DOX is associated with serious adverse effects, including cardiotoxicity and myelosuppression, which limit its effectiveness in antitumor therapy. To overcome these challenges, drug delivery systems (DDSs) have been developed, with polymeric micelles emerging as a highly promising option. In this study, we designed and synthesized a multistage enzyme-responsive amphiphilic molecule, mPEG-GFLGRGDEVD-DOX, for targeted cancer therapy through self-assembly into micelles. Upon cleavage of the GFLG by Cathepsin B, the micelles shed the mPEG crown, thereby exposing the active targeting peptide sequence RGD, which enhances micelle uptake by tumor cells. Concurrently, the DOX loaded in the micelles partially leaks out, inducing apoptosis and activating the apoptotic protease Caspase-3. Caspase-3 then cleaves the DEVD tail, facilitating the rapid intracellular release of the drug. This approach specifically highlights the innovative use of a dual-enzyme cascade (Cathepsin B and Caspase-3) to sequentially trigger tumor-specific drug release, overcoming the limitations of current clinical applications. The synergistic action of these enzymes enhances both drug release and selectivity, offering a promising strategy for improved cancer therapy.

Wearable biosensors are an emerging field in the area of health monitoring, and when they combine with various biopolymers, they provide affordable, sustainable, noninvasive, and real-time monitoring of health. Natural biopolymers such as silk, cellulose, and chitosan offer great potential in the fabrication of these biosensors because of their various properties, such as biocompatibility, flexibility, biodegradability, hydrophilicity, and renewability. These biopolymer-based wearable biosensors provide continuity and comfort with high precision in monitoring health in less time. This Account explores how the remarkable structural and physicochemical properties of these biopolymers support their fabrication and integration into wearable biosensors that can withstand the dynamic environment of the human body. Leveraging these biopolymers enables the development of eco-friendly and skin-conformable biosensors for glucose, lactate, and other biofluids including saliva, sweat, tears, and other interstitial fluids. These biopolymers are of significant importance in the domains of personalized medicine, enhancing athletic performance tracking, and chronic disease management for next-generation wearable devices.

The programmed polarization of macrophages, which exhibit remarkable plasticity from pro-inflammatory (M1) to anti-inflammatory (M2) phenotypes, serves as a key driver of skin wound healing. However, dysregulated macrophage polarization toward a dominant M1 phenotype can induce excessive inflammation and hinder wound healing. Current therapeutic strategies to promote M2 polarization, such as cytokines, anti-inflammatory drugs, and stem cell therapies, have limited effectiveness, complex manufacturing processes, and potential toxicity. Here, we report the development of mannose- and sulfonic acid-modified silk fibroin (SF) that are bioactive and promote M2 polarization by activating the MR-ERK/STAT6 signaling axis. In vitro studies showed increased expression of CD206 and anti-inflammatory gene markers, confirming their ability to regulate macrophage polarization without additional therapeutic agents. Moreover, the mannose- and sulfonic acid-modified SF films, used as wound dressings, enhanced wound healing by promoting M2 macrophage polarization, angiogenesis, collagen deposition, and wound closure. These findings highlight the potential of chemically modified SF as bioactive materials for immune modulation and tissue regeneration.