Journal of Applied Biomaterials & Functional Materials最新文献

Craniofacial bone defects result from various disorders such as trauma, congenital malformations and infections. Cleft lip and palate are the most prevalent congenital craniofacial birth defect in humans. Growth factors (GFs) are soluble proteins secreted by cells that regulate various cellular processes and tissue regeneration. At present, developing three-dimensional scaffolds for delivering GFs to the site of injury has become an important aspect in craniofacial bone regeneration. This study aims to develop a novel 3D bone substitute using lyophilized-platelet-rich fibrin (LyPRF) biocomposite scaffolds for potential application for CLP repair. Collagen (C), bioglass (BG), and LyPRF were used to fabricate a biocomposite (C-BG-LyPRF) scaffold. The physical, chemical, and biocompatibility properties of the scaffold were evaluated. The C-BG-LyPRF scaffold demonstrated a mean pore diameter of 146 µm within a porosity of 87.26%. The FTIR spectra verified the presence of am-ide I, II, and III functional groups. The inorganic phase of the C-BG-LyPRF scaffold was composed of sodium, calcium, silicon, and phosphorus, as determined by EDX analysis. Furthermore, C-BG-LyPRF scaffold was biocompatible with MC3T3-E1 cells in both the Live/Dead and prolif-eration assays. Data demonstrate the developed C-BG-LyPRF scaffold exhibits biomimetic and biocompatibility properties, establishing it as a promising biomaterial for craniofacial regeneration.

Objective: To evaluate the effect of different CAD/CAM materials and occlusal thicknesses on the fracture resistance of primary molar crowns.

Methods: Sixty extracted primary molar teeth were prepared and randomly divided into six experimental groups according to the material and thickness. Primary molar crowns with a central groove thickness of 0.3 and 0.5 mm were fabricated from CAD/CAM zirconia (group Z), zirconia-reinforced lithium silicate (group ZLS), and pre-polymerized composite resin blocks (group C). Each crown was cemented with self-adhesive resin cement on the prepared tooth. All specimens were subjected to fracture tests until fracture. Fracture load values were recorded in Newtons (N). Data were statistically analyzed using a two-way analysis of variance (ANOVA) followed by Tukey multiple comparison test.

Results: The highest fracture load values were obtained in group Z at 0.5 mm occlusal thickness and were significantly higher compared with the other experimental groups (p < 0.05). Although the lowest fracture load values were obtained in group ZLS at 0.3 mm occlusal thickness, all the tested CAD/CAM primary molar crowns at both thicknesses demonstrated fracture load values exceeding reported chewing force in pediatric patients.

Conclusion: CAD/CAM primary molar crowns with reduced occlusal thickness may be used for the full-coverage restoration of primary molar teeth.

This study demonstrates the feasibility of using Irvingia gabonensis shell particulates (IGSp) as alternative reinforcing materials in the development of aluminium-based composites. In this experimental study, the microstructure, phase composition, and mechanical behaviour of Al-10Zn-1.63Si/xIGSp (wt%, x = 1, 3, 5 and 7) composites were investigated. The Al-10Zn-1.63Si based composites were fabricated using the stir-casting technique. Different weight percentages (1, 3, 5 and 7) of IGSp were added to the Al-10Zn-1.63Si matrix. The chemical constituents of the IGSp were determined using X-ray fluorescence (XRF). The grain characteristics and phase(s) compositions were determined using Scanning Electron Microscopy (SEM) and X-ray diffractometer (XRD). The ultimate tensile strength, hardness, and impact strength of the developed composites were also determined. The SEM and XRD results revealed the presence of different phases: aluminium phosphate (Al₁₆P₁₆O₆₄), gahnite (ZnAl₂O₄), andalusite (Al₂SiO₅), Quartz (SiO₂) and aluminium silicate (Al₂O_3.5.SiO₂). Results show that addition of IGSp led to an increase in ultimate tensile strength, with the highest value (128 MPa) obtained at 3 wt% IGSp. The hardness of the composites increased with increasing concentrations of IGSp, reaching a maximum value of 285 HV after adding 7 wt% IGSp. The impact strength improved with the addition of IGSp, with the highest value (30 J) obtained at 1 wt% IGSp. The improvements in mechanical properties were attributed to the dispersion of three major phases: aluminium silicate (Al₂O_3.54.SiO₂), Al₁₆P₁₆O₆₄ and Al₂O_3.54.SiO₂. These phases contributed to the enhanced strength and hardness of the composites. The study noted a sudden decrease in ultimate tensile strength with higher concentrations of IGSp due to the increase in the intensities of Al₁₆P₁₆O₆₄ and precipitation of hard but brittle new phase; Al₂Si_60.6O126.33. The study concludes that IGSp has the potential to serve as an alternative reinforcing material for aluminium-based composites.

Despite the development of implant-supported prostheses, there are still patients for whom conservative treatments such as resin-bonded fixed dental prostheses (RBFDPs) are more appropriate. This study's objective was to analyze the available research on full-ceramic RBFDPs. In this study, Web of Science, MEDLINE/PubMed, Scopus, Embase, Cochrane Library, and Google Scholar databases were searched for articles published in English between 2010 and 2020. A total of 14 studies were reviewed based on the eligibility criteria. The results showed that using a cantilever design with one abutment had an advantage over two abutments. Additionally, it was proposed that preparations designed with retentive aids, such as a proximal box, groove, and pinhole, could improve RBFDP survival rates. IPS e.max ZirCAD, In-Ceram alumina, and zirconia CAD/CAM were the most commonly used framework materials. Most studies used air abrasion, salinization, or hydrofluoric acid for surface treatment. Adhesive resin cements were the most frequently used type of cement. The survival rate of In-Ceram ceramics (85.3%-94.8%) was lower than that of In-Ceram zirconia and IPS e.max ZirCAD. Debonding, followed by framework fracture, was the leading cause of failure. Following 3-10 years follow-up, the survival percentage of all-ceramic RBFDPs ranged from 76% to 100%. Although RBFDPs have demonstrated satisfactory success as a conservative treatment, long-term follow-ups and higher sample sizes in clinical research are required to gain more reliable outcomes on the clinical success rate of various RBFDP designs.

Atomization is a treatment method to make inhaled liquids into aerosols and transport them to target organs in the form of fog or smoke. It has the advantages of improving the bioavailability of drugs, being painless, and non-invasive, and is now widely used in the treatment of lung and oral lesions. Aerosol inhalation as the route of administration of therapeutic proteins holds significant promise due to its ability to achieve high bioavailability in non-invasive pathways. Currently, a great number of therapeutic proteins such as alpha-1 antitrypsin and Dornase alfa are effective. Recombinant humanized collagen type III (rhCol III) as a therapeutic protein is widely used in the biomedical field, but atomization is not a common route of administration for rhCol III, presenting great potential for development. However, the structural stability of recombinant humanized collagen after atomization needs further investigation. This study demonstrated that the rhCol III subjected to atomization through compressed air had retained its original molecular weights, triple helical structures, and the ability to promote cell adhesion. In other words, the rhCol III can maintain its stability after undergoing atomization. Although more research is required to determine the efficacy and safety of the rhCol III after atomization, this study can lay the groundwork for future research.

Objectives: This study aims to investigate the effect of coating time on the formation of hydroxyapatite (HA) coating layer on ZK60 substrate and understand the biodegradation behavior of the coated alloy for biodegradable implant applications.

Methods: Biodegradable ZK60 alloy was coated by HA layer for different times of 0.5, 1, 2, and 4 h by chemical conversion method. After coating, all the coated specimens were used for immersion test in Hanks' solution to understand the effect of coating time on the degradation behavior of the alloy. The degradation rate of the coated alloy was evaluated by Mg²⁺ ion quantification and pH change during immersion test. The microstructure of the coating layer was examined by scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectroscopy (EDS) before and after immersion to understand the degradation behavior of the coated alloy.

Results: HA coating layers were formed successfully on surface of ZK60 specimens after 0.5, 1, 2, and 4 h with different microstructure. Optimal coating quality was observed at 1 or 2 h, characterized by well-formed and uniform HA layers. However, extending the coating duration to 4 h led to the formation of cracks within the HA layer, accompanied by Mg(OH)₂. Specimens coated for 1 and 2 h exhibited the lowest degradation rates, while specimens coated for 0.5 and 4 h showed the highest degradation rates. Furthermore, analysis of degradation products revealed the predominance of calcium phosphates formed on the surface of specimens coated for 1 and 2 h. Conversely, specimens coated for 0.5 and 4 h exhibited Mg(OH)₂ as the primary degradation product, suggesting a less effective corrosion barrier under these conditions.

Conclusion: The HA layer formed after 2 h demonstrated as the most effective coating layer for enhancing the corrosion resistance of the ZK60 alloy for biomedical applications.

Objectives: The primary objective of this study is using an anodizing intermediate layer to improve corrosion resistance and adhesion of hydroxyapatite coated AZ31 alloy for applications in biodegradable implants.

Methods: An anodizing intermediate layer was formed on the surface of AZ31 substrate at various anodizing voltage of 10, 20, 30, and 40 V respectively by anodizing process. HAp was grow on the surface of AZ31 substrate at 90°C and pH solution of 7.5 by chemical solution treatment method for 2 h. The coated samples were evaluated their corrosion behavior by Electrochemical measurements and biodegradation behavior by immersion test in Hank's balanced salts solution (HBSS) for 28 days via amount of Mg²⁺ ion released. While, their adhesion strength were evaluated by pull-off method. The amount of Mg²⁺ ions released of the samples was quantified by the Inductively coupled plasma mass spectrometry.

Results: An anodizing intermediate layer was successfully synthesized at various voltages by anodizing process and HAp coatings were prepared by chemical solution treatment method. The corrosion rate of hydroxyapatite coated AZ31 alloy with an anodizing intermediate layer decreased 4.4 times, while adhesion strength increased about two times compared to the HAp coated AZ31 specimen without an anodizing layer and achieved ~14.70, ~6.92 MPa, respectively. After immersion test in HBSS, the adhesion strength of HAp/AZ31-HBSS-specimen decrease to 45% because of large corroded areas with depth holes of hundreds of micrometers. The slighter decrease in adhesion strength of HAp/30V/AZ31-HBSS-specimen to 22% is due to the contribution of the anodizing intermediate layer.

Conclusion: HAp coated AZ31 alloy specimen with the existence of a porous structure with an elliptical shape, uniform and high density of MgO on the surface at anodizing voltage of 30 V resulted in a significant increase in corrosion resistance and the adhesion strength of HAp coatings.

Human cartilage tissue remains a challenge for the development of therapeutic options due to its poor vascularization and reduced regenerative capacities. There are a variety of research approaches dealing with cartilage tissue engineering. In addition to different biomaterials, numerous cell populations have been investigated in bioreactor-supported experimental setups to improve cartilage tissue engineering. The concept of the present study was to investigate spider silk cocoons as scaffold seeded with adipose-derived stromal cells (ASC) in a custom-made bioreactor model using cyclic axial compression to engineer cartilage-like tissue. For chemical induction of differentiation, BMP-7 and TGF-β2 were added and changes in cell morphology and de-novo tissue formation were investigated using histological staining to verify chondrogenic differentiation. By seeding spider silk cocoons with ASC, a high colonization density and cell proliferation could be achieved. Mechanical induction of differentiation using a newly established bioreactor model led to a more roundish cell phenotype and new extracellular matrix formation, indicating a chondrogenic differentiation. The addition of BMP-7 and TGF-β2 enhanced the expression of cartilage specific markers in immunohistochemical staining. Overall, the present study can be seen as pilot study and valuable complementation to the published literature.