Journal of Applied Biomaterials & Functional Materials最新文献

Objective: Non-carious cervical lesions (NCCLs) are commonly observed in clinical dentistry, leading to tooth fractures, sensitivity, and compromised pulp vitality. Therefore, their restoration is essential for both the aesthetic and structural integrity of teeth. This study aimed to compare the fracture resistance of NCCLs restored using different materials: an injectable universal composite, flowable bulk-fill composites with or without fiber-reinforcement.

Methods: Seventy-five double-rooted maxillary premolars were selected for the study. Fifteen teeth were left intact as a control. A wedge-shaped cavity was prepared in the cervical region of the remaining sixty teeth, which were then divided into four groups (n = 15): unrestored, restored with an injectable composite, restored with a flowable bulk-fill composite (SDR^® flow+), and restored with a flowable short-fiber-reinforced composite (everX Flow™). All teeth underwent fracture testing under oblique static loading at a 30° angle using a universal testing machine. Fracture patterns were classified as repairable, possibly repairable, or unrepairable. Data were analyzed using one-way analysis of variance, Pearson chi-square, and Tukey HSD post hoc tests (p = 0.05).

Results: Intact teeth exhibited the highest fracture resistance (743.481 N), while unrestored teeth showed the lowest (371.49 N) (p < 0.001). There was no significant difference in fracture resistance between the injectable composite (553.289 N) and SDR^® flow+ (497.368 N) (p = 0.055). The everX Flow™ group displayed significantly higher fracture resistance (673.787 N) (p < 0.001) and a repairability rate of 60% within the restored groups. Unrestored (60%), injectable composite (53.3%), and SDR^® flow+ (53.3%) groups were mostly unrepairable.

Conclusion: The everX Flow™ demonstrated improved fracture resistance and favorable fracture pattern for maxillary premolars with wedge-shaped NCCLs.

The pro-inflammatory/anti-inflammatory polarized phenotypes of macrophages (M1/M2) can be used to predict the success of implant integration. Hence, activating and inducing the transformation of immunocytes that promote tissue repair appears to be a highly promising strategy for facilitating osteo-anagenesis. In a previous study, titanium implants were coated with a graphene oxide-hydroxyapatite (GO-HA) nanocomposite via electrophoretic deposition, and the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) was found to be significantly enhanced when the GO content was 2wt%. However, the effectiveness of the GO-HA nanocomposite coating in modifying the in vivo immune microenvironment still remains unclear. In this study, the effects of GO-HA coatings on osteogenesis were investigated based on the GO-HA-mediated immune regulation of macrophages. The HA-2wt%GO nanocomposite coatings exhibited good biocompatibility and favored M2 macrophage polarization. Meanwhile, they could also significantly upregulate IL-10 (anti-inflammatory factor) expression and downregulate TNF-α (pro-inflammatory factor) expression. Additionally, the microenvironment, which was established by M2 macrophages, favored the osteogenesis of BMSCs both in vivo and in vitro. These findings show that the GO-HA nanocomposite coating is a promising surface-modification material. Hence, this study provides a reference for the development of next-generation osteoimmunomodulatory biomaterials.

Joint replacements provide pain free movement for the injured or our aging population. Current prothesis mainly consist of hard metal on metal, or ceramic femoral head on ultra-high-molecular weight polyethylene (UHMWPE). In this study, a rodent fracture model was used to test the influence of wear debris from a high-performance polymer (polyimide MP-1™). Saline, MP-1™ Low Dose in Saline (1%), or MP-1 High Dose (2%) in Saline was injected directly into a standard closed unilateral femoral fracture in 12-week old Sprague Dawley rats (n = 25) for 1, 3 and 6 weeks. Endpoints included radiography, micro-computed tomography, mechanical testing and paraffin histology. No adverse effects from the wear particles were observed from the current study based on radiology, mechanical or histological data. Although the particles were present, histological analysis revealed a progression in healing between the Polyimide treated groups and the non-treated saline control groups over the duration of 1, 3, and 6 weeks, with no inhibition from the particles. The MP-1™ wear debris generated are larger than 1 µm thus are not able to be engulfed by macrophages and cause osteolysis. This family of polymers (polyimides) may be an ideal material to consider for articulating joints and other implants in the human body.

Nanofibrous scaffolds have emerged as promising candidates for localized drug delivery systems in the treatment of cutaneous cancers. In this study, we prepared an electrospun nanofibrous scaffold incorporating 5-fluorouracil (5-FU) and etoposide (ETP) for chemotherapy targeting melanoma cutaneous cancer. The scaffold was composed of polyvinyl alcohol (PVA) and chitosan (CS), prepared via the electrospinning process and loaded with the chemotherapeutic agents. We conducted relevant physicochemical characterizations, assessed cytotoxicity, and evaluated apoptosis against melanoma A375 cells. The prepared 5-FU/ETP co-loaded PVA/CS scaffold exhibited nanofibers (NFs) with an average diameter of 321 ± 61 nm, defect-free and homogenous morphology. FTIR spectroscopy confirmed successful incorporation of chemotherapeutics into the scaffold. Additionally, the scaffold demonstrated a hydrophilic surface, proper mechanical strength, high porosity, and efficient liquid absorption capacity. Notably, sustained and controlled drug release was observed from the nanofibrous scaffold. Furthermore, the scaffold significantly increased cytotoxicity (95%) and apoptosis (74%) in A375 melanoma cells. Consequently, the prepared 5-FU/ETP co-loaded PVA/CS nanofibrous scaffold holds promise as a valuable system for localized eradication of cutaneous melanoma tumors and mitigation of adverse drug reactions associated with chemotherapy.

Hydraulic calcium silicate cements (HCSCs) are valuable for various dental procedures. However, several reports document inherent limitations and complaints about their high costs, hindering accessibility in low-and middle-income countries. This study aimed to characterize four low-cost HCSC prototypes to show their microstructure, composition, and fundamental physical properties. Four HCSC prototypes were formulated: 1- calcium silicate powder with 17.5 wt. % replacement of calcium tungstate, 2- calcium silicate powder with 17.5 wt. % replacement of zirconium oxide, 3- calcium silicate powder with 17.5 wt. % replacement of calcium tungstate and 2.5 wt. % of zirconium oxide and 4- calcium silicate powder with 10 wt. % replacement of calcium tungstate and 10 wt. % replacement of zirconium oxide. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction were used to assess their microstructure and composition. Additionally, radiopacity, setting time, solubility, pH, and in vitro bioactivity were evaluated at different time points and contrasted with controls (Mineral trioxide aggregate -MTA Angelus- and Intermediate restorative material -IRM-). Their production cost was significantly lower than commercially available HCSCs. All prototypes exhibited a microstructure and composition comparable to MTA Angelus. All the prototypes exhibited radiopacity exceeding 3 mm of aluminum and shorter initial and final setting times than MTA Angelus. The solubility of some prototypes closely adhered to the ISO standard recommendation of 3% after 1 day, and all promoted an alkaline pH and the formation of calcium/phosphate precipitates. These promising findings suggest the potential clinical application of these prototypes. However, further research is necessary to evaluate their mechanical and biological properties for definitive clinical use.

High viscosity glass ionomer cements (GICs) are widely used in various clinical applications, being particularly effective in atraumatic restorative treatment (ART) due to the synergistic interaction between the material and the technique. However, the inadequate mechanical properties of GICs raise concerns regarding the predictability and longevity of these restorations in areas exposed to occlusal stress. Various modifications of the powder components have been proposed to improve the mechanical strength of GICs to withstand occlusal loading during mastication. In this in vitro study, we investigated whether the nanoparticles (NPs) added to commercially available GICs could fulfill this requirement, which would likely broaden the spectrum of their potential clinical applications. Two commercially available GIC powders (Fuji IX and Ketac Molar), modified by the addition of 5 wt.% TiO₂, MgHAp100 or MgHAp1000 NPs, were incorporated into the corresponding liquid in an appropriate ratio, and the mixed cements were evaluated in terms of fracture toughness, flexural strength, Vickers microhardness and rheological tests and compared with the original material. Fuji IX containing 5 wt.% MgHAp100 NPs had lower flexural strength, while Ketac Molar with 5 wt.% TiO₂ NPs showed increased fracture toughness. Vickers microhardness increased in Fuji IX following the addition of 5 wt.% TiO₂ and MgHAp100 but decreased in Ketac Molar comprising 5 wt.% MgHAp100 (p < 0.05). Achieving a predictable bond between NPs and cement matrix, as well as ensuring a uniform distribution of the NPs within the cement, are critical prerequisites for enhancing the mechanical performance of the original cement.

Despite advancements in therapeutic techniques, restoring bone tissue after damage remains a challenging task. Tissue engineering or targeted drug delivery solutions aim to meet the pressing clinical demand for treatment alternatives by creating substitute materials that imitate the structural and biological characteristics of healthy tissue. Polymers derived from natural sources typically exhibit enhanced biological compatibility and bioactivity when compared to manufactured polymers. Chitosan is a unique polysaccharide derived from chitin through deacetylation, offering biodegradability, biocompatibility, and antibacterial activity. Its cationic charge sets it apart from other polymers, making it a valuable resource for various applications. Modifications such as thiolation, alkylation, acetylation, or hydrophilic group incorporation can enhance chitosan's swelling behavior, cross-linking, adhesion, permeation, controllable drug release, enzyme inhibition, and antioxidative properties. Chitosan scaffolds possess considerable potential for utilization in several biological applications. An intriguing application is its use in the areas of drug distribution and bone tissue engineering. Due to their excellent biocompatibility and lack of toxicity, they are an optimal material for this particular usage. This article provides a comprehensive analysis of osteoporosis, including its pathophysiology, current treatment options, the utilization of natural polymers in disease management, and the potential use of chitosan scaffolds for drug delivery systems aimed at treating the condition.