Journal of Materials Science: Materials in Medicine最新文献

Via a solid-state reaction route, magnetic composites of chicken eggshell-derived β-tricalcium phosphate (β-TCP, referred to as TCP in the composite system) and zinc-nickel spinel ferrite (ZNF; Zn_xNi_1‒xFe₂O₄, x = 0.2, 0.4, 0.6, or 0.8) were successfully fabricated. Discs were prepared by uniaxial pressing of milled ZNF/TCP powders and sintered at 1200 °C. Cytocompatibility of all composites was confirmed by SEM observations of human osteoblasts (h-OBs) and MTT assays. At 4-wt% ZNF addition, the composites containing Zn_0.8Ni_0.2Fe₂O₄ (Z8NF) exhibited the greatest extent of early cell spreading and were selected for further investigation. For Z8NF/TCP composites containing 4–12 wt% Z8NF, the 8–12 wt% samples demonstrated the highest levels of cell colonization, while MTT assays suggested non-cytotoxic behavior, with cell viabilities comparable to β-TCP. High-temperature sintering induced partial transformation of β-TCP to β-calcium pyrophosphate (β-CPP), as evidenced by XRD and Rietveld refinement. Increasing Z8NF content promoted β-CPP formation and increased composite porosity, whereas densification and Vickers hardness decreased accordingly. Rietveld refinement further indicated that the detectable crystalline Z8NF phase persisted as a minor yet stable secondary phase ( < 2 wt%) and did not participate in Ca–P lattice substitution. For the 8–12 wt% composites, saturation magnetization decreased with increasing Z8NF because of higher porosity and dilution by the non-magnetic β-TCP/β-CPP matrix, while coercivity increased owing to enhanced effective magnetic anisotropy in the more porous microstructure. Overall, the Z8NF/TCP composites combined biodegradability, bioactivity, and tunable soft-magnetic properties, suggesting their potential for bone repair and bone tissue engineering applications.

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The development of bone repair scaffolds has long been a research hotspot in tissue engineering. Owing to its unique capability for personalized customization of scaffold geometry and microstructure, 3D printing technology has been extensively adopted for fabricating bone repair scaffolds. Poly-L-lactic acid (PLLA), endowed with favorable biodegradability, excellent biocompatibility, and reliable in vivo safety, is widely used as a matrix material for 3D printed bone repair scaffolds. PLLA is a bioinert polymer characterized by inferior cell adhesion and osteogenic differentiation capabilities. To mitigate this bioinertness limitation, the present study employed N-methylpyrrolidone (NMP) etching to modify the surface of 3D-printed PLLA bone repair scaffolds. Following NMP etching for 1–24 h, the originally smooth scaffold surface evolved into a hierarchical, petal-like gradient microstructure, accompanied by a marked increase in surface roughness. Correspondingly, the hydrophilicity of the treated scaffolds was also enhanced. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analyses further confirmed that the crystallinity of PLLA in the scaffolds was significantly enhanced. Concomitantly, the modified scaffolds exhibited a marked improvement in adsorption capacity for green fluorescent protein (GFP), while the adhesion and proliferation of MC3T3-E1 on their surface were also significantly promoted. In vivo animal experiments demonstrated that the NMP-etched scaffolds could accelerate the process of bone defect repair. Collectively, surface modification of 3D-printed PLLA bone scaffolds via NMP etching enables precise modulation of their physicochemical properties, thereby effectively mitigating the inherent bioinertness limitation of PLLA scaffolds.

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3D printing is increasingly utilized in dentistry. Compared to traditional manufacturing methods, 3D printing provides advantages such as faster production times and the ability to create complex structures. Although biocompatible materials are available, many are only suitable for temporary applications. This study examines the impact of nitrogen-aided post-processing on the mechanical properties and cytotoxicity of 3D-printed denture bases, with the hypothesis that this post-processing will enhance material properties and decrease cytotoxicity. Specimens were fabricated from V-print dentbase (Voco GmbH, Cuxhaven, Germany) and post-processed either in nitrogen or air. The specimens were categorized into aged and non-aged groups. For comparison, specimens made from milled material were utilized. Vickers hardness, flexural strength, polishability, cytotoxicity, and degree of conversion were then assessed for all groups. The data were analyzed using a one-way ANOVA and Tukey HSD test for multiple comparisons, with a significance threshold of p < 0.05. Post-curing with nitrogen improved the degree of conversion, surface hardness, and biocompatibility of 3D-printed dental materials, confirming reduced cytotoxicity without impairing mechanical properties. Nitrogen increased polymerization and decreased harmful monomers, making it ideal for clinical applications in contact with the oral mucosa. Optimizing post-processing steps, such as curing in nitrogen, enhances biocompatibility while maintaining strength and hardness, ensuring better patient care in dental applications.

Hydroxyapatite-cellulose (HAp-cellulose) composites blend the bioactivity of HAp with the flexibility and biodegradability of cellulose, offering promise in biomedical and industrial fields. In healthcare, they aid bone regeneration, drug delivery, and tissue engineering due to their biocompatibility and porosity. Industrially, they excel in water purification and eco-friendly catalysis. With advancements in 3D printing and electrospinning, these composites enable custom implants and multifunctional scaffolds. Despite challenges in optimizing properties and scalability, future research targets hybrid materials, better fabrication, and regulatory compliance. Their role in smart therapies and environmental cleanup supports global sustainability and circular economy goals. This review summarizes key developments.

This study histologically evaluated the biomineralization process during bone regeneration and the in vivo behavior of a collagen sheet used as scaffolding in a rat 5-mm calvarial defect model. Two experimental groups were established: a group using collagen sheet and bone substitute (BC group), and a group using bone substitute alone (BO group). Bone regeneration was assessed by computed tomography (CT) and both decalcified and undecalcified sections were analyzed using histological staining (hematoxylin and eosin, Villanueva-Goldner [VG], von Kossa, and Join of the Five dyes Revealing CoLlagenous tissue [JFRL]), immunohistochemistry, polarized light microscopy, and low-vacuum scanning electron microscopy (LV-SEM) combined with energy-dispersive X-ray spectroscopy (EDX). CT revealed time-dependent defect reductions, progressing significantly faster in the BC group. In undecalcified specimens, VG staining demonstrated a thick, red, osteoid layer, and serial sections stained with von Kossa showed granular blackish-brown deposits within this layer. LV-SEM/EDX confirmed localized Ca/P accumulation in these deposits, indicating initial biomineralization foci. In decalcified JFRL-stained sections, JFRL color profiles corresponded to gray-scale contrast in LV-SEM images, reflecting collagen fibril organization and the degree of biomineralization. Polarized observation of undecalcified, VG-stained, polished sections revealed the emergence and temporal expansion of orange birefringence within the transplanted collagen sheet and surrounding connective tissue. Immunohistochemistry demonstrated BrdU-, Runx2-, and osterix-positive cells, and osteopontin localization within newly formed matrix in the defect, indicating active osteoblastogenesis. Collagen sheets appear to function not only as physical scaffolding, but also as a bioactive matrix promoting biomineralization by modulating cellular activity and matrix remodeling.

Sodium trimetaphosphate (NaTMP) has demonstrated potential in promoting biomineralization and bone tissue regeneration. However, little is known about the effects of substituting sodium ions with calcium, resulting in calcium trimetaphosphate (CaTMP), within bone engineering contexts. This study synthesized and characterized CaTMP, examining its osteogenic properties in comparison to NaTMP. Both compounds were evaluated in vitro for cytocompatibility and osteogenic potential using MG-63 osteoblast-like cells and bone marrow mesenchymal stem cells (BM-MSC). Assays for cell proliferation, metabolic activity, and alkaline phosphatase (ALP) activity were conducted, along with inductively coupled plasma analysis, gene expression analysis of osteogenic markers, and transmission electron microscopy (TEM) for particles uptake. The results revealed that both NaTMP and CaTMP were biocompatible, supporting cell proliferation and maintaining normal cell morphology. However, CaTMP at a concentration of 50 µg/mL significantly enhanced ALP activity in both MG-63 and BM-MSC cultures, suggesting a stronger osteogenic potential. TEM analysis confirmed the uptake of CaTMP by BM-MSCs, with no evidence of cytotoxicity. In osteogenic medium, BM-MSCs treated with CaTMP showed elevated expression levels of key osteogenic markers—BMP-2, ALP, SP7, Col1a1, SPP1, IBSP, BGLAP, and SPARC—compared to those treated with NaTMP. These findings suggest that CaTMP enhances osteoblastic differentiation more effectively than NaTMP, likely due to calcium’s influence on bone formation pathways. The substitution of sodium with calcium in TMP presents a promising strategy for bone regeneration. Further research is needed to explore CaTMP’s therapeutic potential for bone repair, offering a novel approach to bone tissue engineering.

Graphical Abstract

Hollow silica nanoparticles (HSNPs), characterized by a hollow interior enclosed within a solid mesoporous silica shell, offer several advantages, including low density, high surface area, excellent adsorption capacity, and biocompatibility, making them highly attractive for diverse applications in fields such as food, construction, electronics, imaging, and nanomedicine. To investigate the largely unexplored role of the hollow interior and surface functionality in the design of smart nanocarriers, we propose a facile, green-chemistry-based approach for the synthesis of HSNPs, utilizing polystyrene nanoparticles (64 ± 11 nm in diameter) as sacrificial templates. An ultrathin mesoporous silica shell, 10–12 nm in thickness, is conformally deposited through the controlled hydrolysis of a Si precursor, yielding a nanocarrier system that enables the high adsorption of macromolecules with a pH-sensitive desorption profile. Comprehensive analytical techniques reveal that the method of template removal significantly influences both the interior and exterior pore structures. Notably, calcination produces HSNPs with a higher specific surface area ( > 195 m² g⁻¹), a larger average pore diameter ( ~ 20 nm), and an ink-bottle-like mesoporous structure. It is shown that these structural differences, combined with tailored surface functionalities, critically modulate the triggering response of the nanocarrier. To demonstrate functionality, doxorubicin hydrochloride (DOX) was employed as a model drug. A pH-responsive desorption behavior, releasing the biomacromolecule four times faster at pH=4.5 than at pH=7.4, is presented. This finding underscores the impact of surface chemistry and pore architecture on the adsorption and desorption kinetics of macromolecules. The results of this study pave the way for the rational design of stimuli-responsive ceramic nanocarriers with enhanced adsorption efficiency and precise, controlled desorption capabilities.

The presence of gingival black triangles in the anterior dentition poses significant esthetic and functional concerns. Conventional surgical interventions, despite being the most widely employed techniques, are hampered by inherent invasiveness, technique sensitivity, and unpredictable regenerative outcomes. These limitations drive the need for effective and predictable non-surgical alternatives. Herein, we develop an injectable biomaterial through the self-assembly and self-crosslinking of activated plasma albumin gel (APAG) with concentrated growth factors (CGF), effectively encapsulating bioactive components within a stable network. The APAG/CGF biomaterial exhibits a hierarchical microstructure with uniform porosity and nanofibers, controlled biodegradability, and rich growth factors, collectively constituting a biomimetic microenvironment. Notably, this matrix enables the sustained release of growth factors, which enhance the viability, proliferation, and migration of human periodontal ligament stem cells (PDLSCs) for at least 14 days in vitro. In clinical application, the injection of APAG/CGF into anterior gingival black triangle regions successfully promotes excellent reconstruction of the gingival papillae, with outcomes maintained over a 6-month follow-up period. In conclusion, this study introduces an injectable APAG/CGF biomaterial as a promising non-surgical strategy for gingival black triangle reconstruction by leveraging a biomimetic microenvironment to potentiate essential cellular functions.

The advancement of antimicrobial contact lenses presents a promising strategy for mitigating microbial keratitis. This study investigated the antimicrobial activity of four guanidine-substituted anthranilic amide peptidomimetics (GAMPs), identifying RK1083 as the most potent candidate. The minimum inhibitory concentrations ranged from 20 to 86 µM, with therapeutic indices between 2 and 22. All tested GAMPs exhibited resistance to proteolytic degradation. RK1083 was covalently immobilized onto contact lenses using carbodiimide chemistry, oxazoline plasma deposition, and plasma immersion ion implantation (PIII). The modified lenses demonstrated increased nitrogen content (≥3%), changes in surface charge, and improved hydrophilicity. Adhesion of Staphylococcus aureus was reduced by 5 log₁₀, while Pseudomonas aeruginosa adhesion decreased by ≥5 log₁₀ on oxazoline and PIII-treated lenses, and by ≥3 log₁₀ on carbodiimide-treated lenses. RK1083-coated surfaces exhibited no cytotoxicity toward corneal epithelial cells, and carbodiimide-treated lenses maintained antimicrobial activity post-sterilization. These results underscore RK1083’s potential for enhancing antimicrobial contact lens surfaces with improved bacterial resistance.