ACS Biomaterials Science & Engineering最新文献

Aluminum titanium oxide scaffolds present a highly promising option because of their bioactivity, degradability, and antibacterial characteristics for bone tissue engineering. This makes them a viable alternative to metallic implants, which are susceptible to infection and have limited endurance. The present work aims to examine the impact of sol–gel bioactive glass ceramic coatings on Al₂TiO₅ pellets throughout immersion periods of 12 and 24 h (BG12, BG24). A dual-phase degradation process occurs in these coated scaffolds: first, ion release from the coating stimulates the creation of hydroxyapatite, followed by a progressive breakdown of the Al₂TiO₅ substrate, which further facilitates bone regeneration. An analysis of the structural and mechanical characteristics of coated and uncoated pellets was conducted by utilizing FESEM-EDS, XRD, TG-DTA, FTIR, BET, AFM, and micro-UTM techniques. Findings indicated that the scaffolds consist of a crystalline component of calcium magnesium silicate and calcium sodium aluminum silicate, together with a porous surface. Among the scaffolds, BG24 had the greatest compressive strength of 101 MPa. Bioactivity investigations demonstrated the production of hydroxyapatite in SBF, with a calcium-to-phosphorus ratio of 1.68 attained by BG24 after 14 days. Moreover, BG24 showed 90% cell survival at 100 μg mL^–1, so verifying its cytocompatibility based on biocompatibility and antibacterial tests. Antibacterial research also showed that it effectively stopped the growth of S. aureus and E. coli bacteria, which supports the idea that it might be able to lower the risk of infections in biomedical settings. Because of its improved bioactivity through a dual-phase degradation mechanism, BG24 is a promising option for bone tissue regeneration.

Conductive biomaterials not only have appropriate conductivity but also usually have good antibacterial properties and photothermal effects, so they are widely used in tissue engineering scaffolds. Conductive biomaterials can conduct endogenous or exogenous electrical signals, thus affecting the growth, migration, infiltration, and differentiation of cells. An electrospun nanofiber is an ideal kind of conductive substance carrier that can mimic the extracellular matrix (ECM) to further promote cell growth and migration. In this Review, we summarize the application of electrospinning electroactive tissue engineering scaffolds, discuss the advantages and disadvantages of various electrospinning methods, organize the characteristics of commonly used conductive biomaterials such as polyaniline (PANI), polypyrrole (PPy), poly(3,4-ethylene dioxythiophene) (PEDOT), carbon-based nanomaterials, and MXenes and their application in the tissue engineering field, and finally propose the application prospects and future of tissue engineering with conductive biomaterials.

The human antimicrobial peptide LL-37 exhibits broad antimicrobial efficacy. However, it has several limitations including high production costs, reduced efficacy under physiological conditions, susceptibility to proteolytic degradation and significant toxicity to human cells. Recent research has improved the clinical potential of peptide LL-37 through multiple systematic modifications. Therefore, we review the various modification techniques for LL-37 and explore the structure–activity relationships that underpin its antimicrobial properties. We also highlight the benefits of LL-37 derivatives and investigate their mechanisms of action against bacterial infections, particularly their effects on biofilms and cell membranes. Furthermore, we review the antimicrobial applications of LL-37 derivatives, examine nanocarrier systems for their delivery, and highlight the potential synergy between these derivatives and traditional antibiotics. Finally, it assesses the status of LL-37 derivatives in clinical applications, identifies ongoing challenges, and provides insights into future modifications and potential applications. This review aims to offer valuable strategies for enhancing LL-37 derivatives and facilitating their transition from laboratory research to clinical practice.

Medical stainless steel (SS) is a widely used alloy in orthopedic and dental implant applications. However, SS can cause local corrosion in the body, which may affect cell proliferation and differentiation, and is prone to related bacterial infection. Therefore, surface modification is required to improve the corrosion resistance and antibacterial performance of SS to extend its service life. To achieve this goal, a new type of composite coating was established on the surface of SS. First, zinc oxide (ZnO) nanoparticles were deposited on the surface of SS by electrochemical deposition. Then, polydopamine (PDA) was formed through the self-polymerization of dopamine. Finally, the Michael addition reaction between ε-polylysine (ε-PL) and PDA was used to chemically graft a cationic antimicrobial peptide (AMP), namely, ε-PL, constructing a corrosion-resistant and antibacterial ZnO/PDA/ε-PL coating on the surface of the SS (SZP/ε-PL). The results indicated that the obtained composite coating could significantly improve the corrosion resistance of SS because of the introduction of ZnO. After being irradiated with near-infrared (NIR) light (wavelength: 1064 nm, power: 1 W/cm²) for 8 min, the temperature of SZP/ε-PL increased from 22.4 to 57.8 °C. Moreover, there was no significant temperature decay after four cycles, which indicated the good photothermal performance and stability of SZP/ε-PL owing to the function of PDA. Combining photothermal sterilization and AMP contact sterilization, the antibacterial rates of SZP/ε-PL against Escherichia coli and Staphylococcus aureus both reached nearly 100%. In addition, SZP/ε-PL has excellent blood compatibility. With the above advantages, SZP/ε-PL was expected to become a safe and efficient implant material.

Fibrosis is a dysregulated wound healing response characterized by excessive accumulation of dense scar tissue that inhibits organ function and is estimated to contribute to up to 45% of deaths in the industrialized world. In this work, we sought to uncover new ways to address fibrosis by drawing inspiration from an animal that does not develop fibrosis. The Spiny Mouse (Acomys) has the most extensive regenerative capabilities of any known mammal and can regenerate injuries to the skin, kidney, heart, skeletal muscle, and spine with little to no fibrosis. We hypothesize that the regenerative abilities of Acomys are due, in part, to altered stiffness-mediated fibroblast-to-myofibroblast transition (FMT). In this work, we interrogated stiffness-mediated FMT in Acomys and Mus dermal fibroblasts in vitro by performing RNA Sequencing and found no differential gene expression in Acomys fibroblasts cultured on soft vs stiff substrates. We further investigated the direct impact of stiffness-mediated FMT and species differences on ECM deposition by fabricating cell-derived matrices (CDMs) from Acomys and Mus fibroblasts cultured on varying stiffnesses. After assessing the composition of these CDMs using label-free quantitative proteomics, fibrosis-associated extracellular matrix proteins including fibrillin-1, ADAMTS1, SPARC, and galectin-1 were found to be significantly reduced or absent in Acomys CDMs compared to Mus CDMs. In addition, proteins that have been connected to fibrosis resolution, including Col12a1 and clusterin, were upregulated in Acomys CDMs. When cultured on Acomys CDMs, mouse macrophages downregulated MMP9 mRNA expression and maintained increased expression of iNOS in response to IL-4, a pro-fibrotic cytokine. These results indicate a direct impact of species-specific ECM compositions on macrophage phenotype and suggest that ECM produced by Acomys fibroblasts may impede the development of a pro-fibrotic macrophage phenotype in the presence of pro-fibrotic stimuli.

The skin is a complex organ composed of multiple layers and diverse cell types, including keratinocytes, fibroblasts, adipocytes, and sensory neurons, which maintain its structural and functional integrity together. Conventional in vitro and ex vivo models help investigate drug permeation and selected biological effects. However, they are limited in replicating neural interactions critical for assessing the efficacy of neuropeptide-based therapies. To address this limitation, a sensory neuron-integrated skin spheroid (SS) model was established, incorporating key skin cell types and providing a rapid, adaptable, and physiologically relevant platform for screening the biological activity of topical delivery systems targeting neuronal pathways. The model’s responsiveness was demonstrated using acetyl hexapeptide-3 (HEX-3), a neuropeptide that inhibits acetylcholine release. HEX-3 was internalized by spheroid cells, with preferential accumulation around sensory neurons, confirming targeted cellular uptake. In parallel, ex vivo human skin studies confirmed that HEX-3 can traverse the stratum corneum and accumulate in deeper layers. Treatment with this film enhanced skin hydration, reduced scaling, and improved the structural organization of the stratum corneum after 48 h. Functional assays using the SS model showed that HEX-3 treatment suppressed acetylcholine release, upregulated the antioxidant enzyme SOD2, and stimulated type I collagen synthesis. In aged skin samples, the application of HEX-3 significantly increased collagen levels. This effect was mirrored in the spheroid model, which reached collagen levels comparable to those of aged human skin upon treatment. These findings establish the SS model as a robust platform for evaluating the biological activity of neuropeptide-based topical therapies, offering valuable insights for developing advanced strategies for skin rejuvenation and repair.

Complex wound management remains a significant global challenge, and the development of multifunctional wound dressings that can effectively promote wound healing remains an urgent clinical need. Herein, a kind of multifunctional hydrogel wound dressing that combines bacteriostasis, self-healing capability, growth factor release, electrical stimulation, and photothermal stimulation is developed. This kind of wound dressing is generated by adding protocatechualdehyde (protocatechuic aldehyde (PA)), short core–shell fibers loading with platelet-rich-plasma (platelet-rich plasma fibers), and polydopamine-coated carbon nanotubes (PDA@CNTs) into quaternary ammonium chitosan (QCS) solution to form a shear-reversibly cross-linked QCS/PA/PDA@CNTs-PRP hydrogel. The obtained hydrogels possess impressive properties, including high swelling capacity (445–852%), strong adhesion ability (16.4–36.7 kPa), self-healing ability, injectability, conductivity (0.24–0.46 S/m), and photothermal properties. Notably, under near-infrared irradiation, the hydrogel exhibits a highly efficient bactericidal activity. In vitro experiments demonstrated that the hydrogel exhibits excellent biocompatibility and anti-inflammatory capability as well as its ability to stimulate cell proliferation, migration, and tubule formation. Moreover, the in vivo studies further confirmed that with the additional assistance of near-infrared light and electrical stimulation, the hydrogel further promotes wound epithelization, angiogenesis, and collagen deposition. Consequently, this hydrogel provides a promising therapeutic strategy for complex wound healing.

Spinal cord injury (SCI) is a central nervous system (CNS) disease with a high disability rate, and reconstructing motor function after SCI remains a global challenge. Recent advancements in rehabilitation and regenerative medicine offer new approaches to SCI repair. Electrical stimulation has been shown to alter cell membrane charge distribution, generating action potentials, and affecting cell behavior. This method aids axon regeneration and neurotrophic factor upregulation, crucial for nerve repair. Biomaterials, used as scaffolds or coatings in cell culture and tissue engineering, enhance cell proliferation, migration, differentiation, and tissue regeneration. Electroactive biomaterials combined with electrical stimulation show promise in regenerating nerve, heart, and bone tissues. In this paper, different types of electrical stimulation and biomaterials applied to SCI are described, and the current application and research progress of electrical stimulation combined with biomaterials in the treatment of SCI are described, as well as the future prospects and challenges.

Full-thickness wounds pose significant healing challenges due to their impaired regenerative capacity, persistent inflammation, and oxidative stress. Enhancing the bioactivity of silk fibroin (SF) and the mechanical strength of the human amniotic membrane (hAM) can improve wound healing outcomes. Mesenchymal stem cell (MSC)-derived small extracellular vesicles (sEVs) offer promising anti-inflammatory and antioxidant benefits, but their poor retention and painful application limits their clinical utility. To overcome these challenges, we developed a composite scaffold of SF and hAM (Sh), loaded with sEVs (ShE), designed to accelerate wound healing by modulating inflammation, oxidative stress, and tissue regeneration. ShE exhibited excellent physical stability, optimal swelling, degradation kinetics, hemocompatibility, and sustained sEV release. In vitro, it enhanced keratinocyte and fibroblast proliferation and migration, reduced oxidative stress, and provided immunomodulatory and pro-angiogenic effects. ShE significantly lowered ROS levels, suppressed PHA-activated PBMNC proliferation, facilitated macrophage polarization from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype, and promoted angiogenesis. In vivo, ShE accelerated wound closure within 21 days, outperforming DuoDERM, a commercial dressing. Histopathological analysis demonstrated improved epidermal maturation, dermal regeneration, and reduced scarring in ShE-treated wounds, confirming the superior tissue regeneration capacity. Additionally, its fabrication from medical waste and indigenous raw materials ensures cost-effectiveness and sustainability in healthcare applications. By synergistically regulating cell physiology for skin regeneration, ShE emerges as a promising, clinically viable, and affordable wound dressing for enhanced wound care management.