Journal of Materials Science: Materials in Medicine最新文献

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.

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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.

The skin, the largest organ of the human body, plays a crucial role in maintaining homeostasis and protecting against external influences. Although it possesses remarkable self-healing capabilities, severe or chronic injuries often necessitate external intervention. In this context, wound management and targeted drug delivery are central areas of biomedical research, where the development of smart biomaterials and the concept of smart wound dressings have revolutionized treatment strategies. Among the various biomaterials, polysaccharide-based wound dressings—particularly dextran-based hydrogels—have gained growing attention due to their excellent biocompatibility, biodegradability, non-toxicity, and clinical safety. Dextran hydrogels exhibit exceptional properties, including high water retention, tunable mechanical strength, and responsiveness to various external stimuli, making them ideally suited for advanced medical applications. This review provides a comprehensive overview of stimuli-responsive polysaccharide hydrogels, with a focus on dextran-based systems. It begins with a discussion of skin structure and function, wound healing mechanisms, and the limitations of chronic and diabetic wounds, highlighting the need for advanced biomaterials. The review then summarizes advances in the design of dextran-based hydrogels, focusing on stimulus responsiveness mechanisms, manufacturing strategies, and crosslinking techniques. Particular attention is paid to their biomedical applications in wound healing and drug delivery, emphasizing mechanisms for controlled release, antimicrobial activity, and tissue regeneration. The review concludes with critical insights into current challenges and future directions for the clinical application of dextran-based hydrogels.

Graphical Abstract

Guided bone regeneration (GBR) is a critical regenerative strategy for repairing periodontal tissues and craniofacial bone defects. It can establish space to prevent undesirable soft tissue invasion and improve bone regeneration. However, commercially available GBR membranes have some disadvantages in terms of biocompatibility and antibacterial efficacy. Hence, we prepared a polycaprolactone (PCL) membrane by electrospinning and then in situ synthesized vancomycin-assisted zeolitic imidazolate framework-8 (Van-ZIF-8) nanoparticles on its surface. With the formation of Van-ZIF-8, the mechanical properties of the PCL membrane were significantly enhanced. Moreover, the release rates of Van and zinc ions (Zn²⁺) showed pH responsiveness. In an acidic environment (pH 5.4), the fast hydrolysis of Van-ZIF-8 led to the rapid release of Van and Zn²⁺. The PCL/Van-ZIF-8 membrane exhibited enhanced antibacterial activity against both aerobic and anaerobic bacteria, including Staphylococcus aureus, Escherichia coli, Porphyromonas gingivalis, and Streptococcus mutans, through the hydrolysis of Van-ZIF-8 nanoparticles. Furthermore, the in vitro results for MC3T3-E1 and L929 cells, including cell viability, alkaline phosphatase activity, mineralization level, collagen secretion, gene expression, and fluorescence staining, demonstrated that the PCL/Van-ZIF-8 membrane possessed excellent osteoinductive capacity and could act as an ideal physical barrier to fibroblast growth.

Graphical Abstract

Schematic illustration of the PCL/Van-Zif-8 electrospinning membrane fabrication and its promotion of mechanical, osteogenesis, and antibacterial properties.

Purpose

The review provides an in-depth analysis of various factors that affect the long-term success of implants and scrutinizes all available techniques for dental implant modifications, along with their advantages and limitations. Along with established and proposed strategies, newer trends such as responsive coatings, ‘omics’ and AI-based possibilities for translating research into clinical settings are discussed.

Methods

The available scientific literature on dental implants, causes for their failures, and possible surface modification techniques was collected and analyzed. Strategies to prevent implant failures are presented as a comprehensive, structured review.

Results

A literature review of scientific research papers published over the last decade clearly indicates that surface modification of dental implants is critical for ensuring long-term success. Strategies aimed at surface changes consider the intrinsic antibacterial activity, surface texture, and geometry of the implant material. In both healthy and compromised patients, bio-functionalized surfaces can improve osseointegration and reduce peri-implantitis, boosting the success of dental implants.

Conclusions

Dental implants, while promising, face hurdles that hinder their long-term success. Modifying implants through physical, chemical, or mechanical methods could potentially address these challenges. These techniques would require clinical validation before being fully integrated into clinical practice. Moreover, crucial factors such as immune response and in vivo testing are often overlooked.

Tissue adhesives are regularly used for wound healing, bleeding control and sealing internal organ leakages. However, currently available tissue adhesives are often cytotoxic. Polycations containing primary amines are generally known to induce cytotoxicity. Complex coacervates, composed of oppositely charged polyelectrolytes, may offer a biocompatible alternative. In this study, primary amines of polyallylamine hydrochloride (pAH) were reacted with glycidyltrimethylammonium chloride (GTMAC) following an epoxide ring nucleophilic substitution to obtain pAH with quaternary ammonium pendant groups (q-pAH). These polycations were combined with negatively charged polysulfopropyl methacrylate (pSPMA) to form complex coacervates. The biocompatibility of the individual polyelectrolytes and resulting complex coacervates was studied using A549 cells through Live/Dead, MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) and LDH (lactate dehydrogenase) assays. Additionally, adhesion to porcine tissues was evaluated. Quaternization of pAH strongly reduced the critical salt concentration (CSC) of the coacervate system, while remaining easy to process and injectable. The cytocompatibility of q-pAH/pSPMA was increased compared to pAH/pSPMA, mainly caused by the reduction of the required salt concentration. Nevertheless, quaternization did not reduce the cytotoxicity of the polycation itself. Complexation with pSPMA effectively reduced cytotoxicity through charge neutralization. Upon direct contact of A549 cells with q-pAH/pSPMA coacervates improved biocompatibility was observed compared to pAH/pSPMA, which could not be fully attributed to effects of reduced salt levels. Both coacervates formed stable, gel-like patches upon the salt switch and these adhered to various tissues. Reduction of complex coacervate cytotoxicity by polycation quaternization can be included in future designs of medical adhesives.

Graphical Abstract