ACS Biomaterials Science & Engineering最新文献

Hydrogel microparticles (microgels) have significant potential for use as building blocks in tissue engineering, as bioinks for 3D bioprinting, and as drug and cell carriers for cell-based therapies targeting damaged and diseased tissues. Various fabrication techniques have been developed for producing microgels with predefined shapes and sizes. However, for practical applications in biological laboratories and clinics, it is necessary to reduce time costs and simplify instrumentation and synthesis protocols, improving their reproducibility and reliability. Here we demonstrate a three-step experimental approach to develop microfluidic flow-focusing droplet generators that enable the introduction of all liquids by creating negative pressure in the outlet reservoir for the generation of spherical, core–shell, and Janus alginate microgels with living cells. This approach allows the use of a simple experimental setup that is easy to operate and robust and provides highly reproducible results, achieving a synthesis performance of up to 200 μL of microgels per hour. The size and the structure of the microgels were determined by the chip design and remained stable under pressure variations within the operating range of −7 to −15 kPa. This enabled the reliable and reproducible encapsulation of CT26 and HepG2 cells into core–shell and Janus alginate microgels with diameters ranging from 80 to 120 μm, maintaining over 80% cell viability during long-term incubation. Our findings offer a new perspective for the automation and scaling of multicomponent alginate microgel fabrication, paving the way for their implementation in tissue engineering and 3D bioprinting.

Stemness of mouse embryonic stem cells (mESCs) can be maintained in vitro using biophysical factors including surface topography. More specifically, multidirectional symmetries have shown promise in limiting cell-substrate interactions, yielding better stemness maintenance. Here, a parylene-C coating was deposited onto binary colloidal crystals (BCCs) to generate imprinted substrates with concave bowl-like micro/nanotopographies possessing multidirectional symmetry. Remarkably, the parylene coating is shown to have the fidelity to imprint sub-2 μm structures. The mESC response to these topographies observed in culture demonstrates the complementary influence of microtopography and nanotopography. While the nanoroughness associated with the small particle imprints appears to govern the attachment of cells, the microroughness associated with large particle imprints is able to limit the interaction of cells with the substrate thereby confining spreading. Our results demonstrate that imprinted BCCs with the combination of 5 μm (large) and 110 nm (small) particle imprints are able to provide spatially limited attachment of cells, resulting in improved colony shape, enhanced growth rate and upregulation of the expression of stemness markers of mESCs in culture in the presence of LIF. Our results are expected to contribute to the development of novel cell culture substrates for use in the efficient expansion of stem cells for tissue engineering and regenerative medicine applications.

The sharp-edged structure of inorganic nanomaterials has attracted considerable interest due to its potential to confer broad-spectrum antiviral properties. Herein, a series of hydroxyapatite-balance-based (HA-B) nanorods with well-defined aspect ratios were synthesized to investigate their antiviral activity. Among them, HA-B_0.05wt% exhibited the highest aspect ratio (AR = 11.7 ± 4.7) and demonstrated potent, broad-spectrum antiviral activity against enveloped virus, including pseudorabies virus (PRV, DNA virus), transmissible gastroenteritis virus (TGEV, RNA virus), and porcine epidemic diarrhea virus (PEDV, RNA virus). For extracellular viruses, HA-B_0.05wt% exerts its antiviral effect primarily through the physical disruption of viral envelopes, facilitated by its sharp-edged nanostructures. In the case of intracellular viruses, HA-B_0.05wt% mitigates infection by attenuating virus-induced intracellular reactive oxygen species (ROS) accumulation and activating the host’s innate immune responses, thereby effectively suppressing viral replication and release. Furthermore, in vivo evaluation demonstrated that treatment with HA-B_0.05wt% significantly reduced viral load and improved survival rates in PRV-infected mice. Collectively, these findings highlight HA-B_0.05wt% as a promising candidate for broad-spectrum antiviral therapy with potential applications in biosecurity and infectious disease control.

Nanoparticles (NPs) offer significant advantages over conventional drug formulations, including enhanced bioavailability, reduced toxicity, and controlled release. Human serum albumin (HSA) is a biocompatible material widely used for NP fabrication, exemplified by Abraxane, an HSA-based NP formulation that improves chemotherapy delivery. Despite these benefits, HSA-NPs predominantly rely on passive tumor targeting through enhanced permeability and retention effect. Attempts to enhance active targeting via surface modifications often trigger immune responses, while scalable production remains limited by inconsistencies in size, drug loading, and stability. Here, we introduce a variant HSA (VA) as a building block for a novel nanocarrier, VA-NPs. Engineered with an α-helical domain that pairs with a complementary α-helical counterpart, VA enables VA-NPs to self-decorate their surface with diverse payload proteins through spontaneous and specific coiled-coil interactions. Unlike traditional approaches, this strategy eliminates the need for chemical conjugation or genetic fusion, establishing VA-NPs as a modular platform for multifunctional nanomedicines. This programmable protein display method offers a scalable and clinically relevant solution to current limitations in nanoparticle-based drug delivery, paving the way for next-generation nanomedicines with enhanced specificity, functional versatility, and therapeutic efficacy.

Delivering plasmid DNA (pDNA) into cells is essential for numerous biotechnological and biomedical applications. Among available nanocarriers, nonviral lipid-based vesicles are particularly promising for transfecting mammalian cells. Nevertheless, further development is required to create delivery systems that are both broadly effective across cell types and scalable for clinical use. Here, we explore stable nanovesicles composed of the sterol derivative cholesteryl N-(2-dimethylaminoethyl)carbamate (DC–CHOL) and myristalkonium chloride (MKC) as a platform for pDNA delivery. These nanovesicles, previously shown to efficiently deliver small RNAs to neuroblastoma cells, exhibit favorable physicochemical properties, such as high morphological uniformity and long-term colloidal stability, positioning them as strong candidates for DNA transfection. Using suspension-adapted human embryonic kidney 293 (HEK293) cells, which are widely employed for producing viral vectors and complex biotherapeutics, we evaluated the delivery performance of DC–CHOL/MKC nanovesicles with a reporter plasmid encoding enhanced green fluorescent protein. A Design of Experiments (DoE) approach was applied to identify and optimize critical transfection parameters, namely, the DNA concentration, DNA-to-vesicle ratio, and NaCl concentration in the complexing medium. This study demonstrates the capability of these nonviral vectors to deliver double-stranded plasmid DNA and emphasizes the critical role of the physicochemical characteristics of the pDNA/lipid complex in achieving efficient transfection.

External thermal and electrical stimulations are widely explored to promote tissue regeneration; yet, integrating both modalities into a single, programmable soft film remains challenging. Here, we present a flexible photoresponsive hybrid film composed of a poly(vinylidene fluoride) matrix incorporating polydopamine-coated BaTiO₃ nanoparticles, fabricated via spin-coating. This composite (denoted as PVDF/PDA@BTO) exhibits a dual-mode functionality that enables both steady and pulsed stimulations within a single biocompatible platform. Under continuous near-infrared irradiation, the film delivers stable photothermal outputs, maintaining target temperatures of 37 or 42 °C. Under pulsed irradiation, transient thermal variations trigger the pyroelectric response of BaTiO₃, producing synchronized voltage outputs tunable by pulse duration, with ∼250 mV generated during a 0.25 s pulse. As a proof of concept, the film significantly accelerated rewarming and tissue repair in a mouse frostbite model. This work demonstrates a facile strategy for constructing programmable, multifunctional polymer–inorganic hybrid films with potential in on-demand bioelectronic interfaces and soft therapeutic devices.

Shark-derived variable new antigen receptors (VNARs) exhibit broad biomedical application prospects owing to their small size, exceptional thermal stability, and resistance to extreme pH conditions. Synthetic library construction enables the selection of specific VNARs without shark immunization, while employing stable universal scaffolds with rationally designed complementarity-determining region 3 (CDR3) length and amino acid composition. Here, a synthetic phage display library was constructed using a highly expressed and stable scaffold, guided by a systematic analysis of existing VNAR sequences. Its framework regions were retained, while the CDR1 and CDR3 were randomized with the conserved tryptophan (W) in CDR3 preserved. Using this library, VNARs specifically targeting the urinary tumor biomarkers hyaluronidase-1 (Hyal-1), Engrailed-2 (EN2), and prostate-specific antigen (PSA) were successfully identified. The affinity of all selected VNARs reached the micromolar (μM) level, and the expression level can reach 2.4–14.3 mg/mL. In summary, this study established a high-performance synthetic VNAR phage display library and preliminarily explored the role of the conserved tryptophan (W) in the CDR3. The VNARs targeting distinct epitopes of Hyal-1, EN2, and PSA obtained through screening represent promising candidate molecules for the diagnosis and treatment of related cancers.

Arterial hemorrhage with high-pressure, spurting blood loss can rapidly cause shock or death. Developing ideal hemostatic materials that combine rapid hemostasis, mechanical stability, antibacterial properties, and biocompatibility remains a challenge. This study reported a nanocomposite hemostatic sponge TCCND/CPL through cross-linking carboxymethyl chitosan (CMCS) and sodium carboxymethyl cellulose (CMC-Na), reinforced with nanodiamonds (NDs), and loaded with chloramphenicol (CPL) and thrombin to improve arterial hemorrhage management in irregular wounds. The incorporation of ND makes TCCND/CPL achieve a wet-state compressive stress of 44.9 kPa, which markedly exceeds typical clinical arterial systolic pressure, while maintaining elasticity, rapid absorption, and retention. Both in vitro and in vivo assessments confirmed TCCND/CPL’s exceptional hemostatic capability, demonstrating superior performance to commercial agents in rat tail amputation, rat irregular trauma, femoral artery puncture, and noncompressible rabbit wound models. It achieved rapid hemostasis in just 126 s (22.7% faster than the military-grade ChitoGauze XR PRO), and the hemostatic effect was about 2.5 times that of the conventional gauze and 1.67 times that of ChitoGauze XR PRO in a rabbit femoral artery puncture model. Additionally, TCCND/CPL demonstrated significant antibacterial activity and excellent biocompatibility. The innovative design of TCCND/CPL provides an efficient solution for managing irregular wound hemorrhage in emergency scenarios such as battlefield injuries and traffic accidents.

Biomolecular hydrogels demonstrate potential for bone regeneration because of their aqueous biocompatibility and low toxicity; however, their mechanical fragility and insufficient bioactivity significantly constrain osteogenic application. Herein, cellulose nanocrystals (CNCs) were introduced into poly(vinyl alcohol) (PVA) hydrogels to improve their mechanical properties and osteogenic regeneration potential. The hydroxyl-rich structure of CNCs facilitates dynamic hydrogen bonds that increase mechanical strength and stabilize the porous matrix, thereby augmenting the barrier function against fibroblasts. The mechanical reinforcement and high density of surface hydroxyl groups conferred by CNCs markedly promote bone tissue regeneration. PVA hydrogels were prepared via a freeze–thaw process, incorporating different CNCs concentrations to evaluate their effects on tensile and compressive strength. PVA/CNC2 and PVA/CNC5 hydrogels, which exhibited mechanical adaptability, were selected for further investigation. We studied the proliferation and osteogenic differentiation of MC3T3-E1 cells in response to these hydrogels. Moreover, the bone healing performance of the PVA/CNCs hydrogels was assessed using a rat critical-sized calvarial defect model. We also conducted transcriptomic sequencing to investigate the osteogenic mechanisms of the PVA/CNCs hydrogels. This study demonstrates how hydroxyl-enriched surfaces facilitate bone tissue regeneration, emphasizing a dynamic hydrogen bond-mediated cross-linking strategy to enhance hydrogel mechanical properties. The findings offer a theoretical framework and technical guidance for the development of advanced hydrogel-based biomaterials with tailored mechanical properties and regenerative capabilities.

Repairing critical bone defects is a clinical challenge that urgently needs to be addressed. 3D bioprinting strategies using bioinks composed of living cells and hydrogel biomaterials can mimic natural tissues, offering a novel repair approach. In particular, the freeform reversible embedding of suspended hydrogels (FRESH) technique employs a support bath to stabilize mechanically weak hydrogels during printing while maintaining their biocompatibility. In this study, we fabricated a 3D bioprinter, and prepared a bioink composed of monetite, sodium alginate, and hydroxypropyl methylcellulose. The rheological properties of the bioink were subsequently evaluated to ensure its printability. Following 3D printing, the chemical compositions and microstructures of the scaffolds generated from the bioink were analyzed to confirm their suitability for cell growth applications. We further incorporated rat bone marrow stem cells into the bioink to create 3D bioprinted cellular scaffolds. Preliminary in vitro tests demonstrated the excellent biocompatibility and early osteogenic induction capabilities of the scaffolds. These 3D bioprinted cellular scaffolds were subsequently implanted into a rat skull defect model, and radiological and histological analyses revealed that the combination of monetite and rat bone marrow stem cells synergistically enhanced osteogenesis in vivo. Our study was the first to apply FRESH to in vivo osteogenesis, demonstrating that 3D bioprinted cellular scaffolds containing monetite promoted bone regeneration and provided a novel strategy for the clinical translation of bone regeneration.