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Comparative investigation into effects of ZrO <sub/>2</sub> and Al <sub/>2</sub> O <sub/>3</sub> addition in fluorapatite laser-clad composite coatings on Ti6Al4V alloy
摘要： Composite coatings consisting of fluorapatite mixed with 20 wt% yttria (3 mol%) stabilized cubic phase zirconia (c-ZrO2, 3Y-TZP) or 20 wt% alumina (a-Al2O3) were deposited on Ti6Al4V substrates using a Nd:YAG laser cladding system. The interface morphology, phase composition, micro-hardness and biological properties of the two coatings were examined and compared. The results showed that the fluorapatite/Al2O3 specimen underwent a greater inter-diffusion at the interface between the coating layer and the transition layer than the fluorapatite/ZrO2 specimen. During the cladding process, the ZrO2 and Al2O3 components of the coating were completely decomposed or underwent phase transformation. In addition, the fluorapatite was partially decomposed. For both specimens, the coating layers contained fluorapatite, CaF2 and CaTiO3 phases. The coating layer of the fluorapatite/ZrO2 specimen additionally contained TTCP, CaO, CaZrO3 and m-ZrO2 (monoclinic phase), while that of the fluorapatite/Al2O3 specimen contained b-TCP, CaAl2O4 and u-Al2O3. The average micro-hardness of the fluorapatite/ZrO2 coating layer (1300 HV) was approximately 200 HV higher than that of the fluorapatite/Al2O3 coating layer (1100 HV). Both specimens generated dense bone-like apatite following immersion in simulated body fluid for 3 days. In other words, both specimens had a good in vitro bioactivity. However, the fluorapatite/ZrO2 specimen showed a better initial attachment and spread of osteoblast-like osteosarcoma MG63 cells than the fluorapatite/Al2O3 specimen in in vitro biocompatibility tests performed for 24 h.
关键词： Ti6Al4V,bioactivity,biocompatibility,alumina,laser cladding,Fluorapatite,zirconia
更新于2025-09-23 15:23:52
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Enhancement of osteoblast activity on nanostructured NiTi/hydroxyapatite coatings on additive manufactured NiTi metal implants by nanosecond pulsed laser sintering
摘要： Background: The osteoinductive behaviors of nitinol (NiTi)-based metal implants for bone regeneration are largely dependent on their surface composition and topology. Continuous-mode laser sintering often results in complete melting of the materials and aggregation of particles, which lack control of heat transfer, as well as microstructural changes during sintering of the nanocomposite materials. Methods: In the current study, in situ direct laser deposition was used to additively manufacture three-dimensional NiTi structures from Ni and Ti powders. The mechanical property of NiTi has been shown to be similar to bone. Nanosecond pulsed laser sintering process was then utilized to generate a nanoporous composite surface with NiTi alloy and hydroxyapatite (HA) by ultrafast laser heating and cooling of Ni, Ti, and HA nanoparticles mixtures precoated on the 3D NiTi substrates; HA was added in order to improve the biocompatibility of the alloy. We then studied the underlying mechanism in the formation of NiTi/HA nanocomposite, and the synergistic effect of the sintered HA component and the nanoporous topology of the composite coating. In addition, we examined the activity of bone-forming osteoblasts on the NiTi/HA surfaces. For this, osteoblast cell morphology and various biomarkers were examined to evaluate cellular activity and function. Results: We found that the nanoscale porosity delivered by nanosecond pulsed laser sintering and the HA component positively contributed to osteoblast differentiation, as indicated by an increase in the expression of collagen and alkaline phosphatase, both of which are necessary for osteoblast mineralization. In addition, we observed topological complexities which appeared to boost the activity of osteoblasts, including an increase in actin cytoskeletal structures and adhesion structures. Conclusion: These findings demonstrate that the pulsed laser sintering method is an effective tool to generate biocompatible coatings in complex alloy-composite material systems with desired composition and topology. Our findings also provide a better understanding of the osteoinductive behavior of the sintered nanocomposite coatings for use in orthopedic and bone regeneration applications.
关键词： metal implants,pulsed laser coating,biocompatibility,differentiation,bone regeneration,alkaline phosphatase,osteoinductive behavior
更新于2025-09-23 15:22:29
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Direct carbonization of organic solvent toward graphene quantum dots
摘要： The bottom-up synthesis of graphene quantum dots (GQDs) using solvothermal method has attracted considerable attention because of their fewer defects and controllable size/ morphology. However, the influence of organic solvent on the preparation of GQDs is still unknown. Herein, a systematic study about carbonization of organic solvents toward GQDs is reported. Results show that organic solvent with the double bond or benzene ring or double hydrophilic groups could be directly decomposed into GQDs without the addition of catalysts or molecule precursors. The as-synthesized GQDs demonstrate ultra-small size distribution, high stability, and excitation wavelength-tunable and upconverted fluorescence. Both hematological and histopathological analyses studies show that the as-synthesized GQDs demonstrate a much good safety profile and excellent biocompatibility. The versatility of this synthetic strategy allows easy control of the surface group, composition, and optical properties of GQDs at the molecular level.
关键词： organic solvents,biocompatibility,fluorescence,graphene quantum dots,solvothermal synthesis
更新于2025-09-23 15:21:01
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Contents: (Adv. Funct. Mater. 36/2018)
摘要： In article number 1800802, Hyunjoo J. Lee and co-workers present a calcium-modified silk fibroin film as a strong adhesive for next-generation epidermal electronics. The modified silk film exhibits viscoelastic properties and can mechanically interlock a sensor and the skin surface ~20 times stronger than commercial alternatives. Additional interesting characteristics, such as good biocompatibility, reusability, stretchability, and conductivity show promise for widespread application.
关键词： epidermal electronics,biocompatibility,conductivity,silk fibroin,reusability,stretchability
更新于2025-09-23 15:21:01
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Mesoporous multi-silica layer-coated Y2O3:Eu core-shell nanoparticles: Synthesis, luminescent properties and cytotoxicity evaluation
摘要： Mesoporous multi-layered silica-coated luminescent Y2O3:Eu nanoparticles (NPs) were prepared by a urea-based decomposition process, and their surfaces were gradually modified with nanoporous and mesoporous silica layers using modified sol-gel methods. The synthesized luminescent core-shell NPs were characterized thoroughly to investigate their structural, morphological, thermal, optical, photo luminescent properties and their surface chemistry. The morphology of the core NPs were nearly spherical in shape and were nano-sized grains. The observed luminescent efficiency of the mesoporous multi-layered silica-coated luminescent core NPs was gradually reduced because of bond formation between the Y2O3:Eu core and the amorphous silica shell via YeOeSieOH bridges on the surface of the NPs; the bonds suppressed the non-radiative transition pathways. Biocompatibility tests on human breast cancer cells using the 3?(4,5?Dimethylthiazol?2?yl)?2,5?diphenyltetrazolium bromide and lactate dehydrogenase assays indicated that the core-shell NPs were non-toxic even at high concentrations. The mesoporous SiO2 layer played a key role in perfecting the solubility, biocompatibility, and non-toxicity of the NPs. The zeta potential, surface chemistry (Fourier transform infrared spectroscopy), and optical absorption spectral analyses revealed the high hydrophilicity of the as-prepared core-shell NPs because of the active surface-functionalized silanol (SieOH) groups, which could potentially offer many exciting opportunities in photonic-based biomedical applications.
关键词： Cytotoxicity,Mesoporous silica shell,Photoluminescence,Yttrium oxide,Raman spectra,Biocompatibility
更新于2025-09-23 15:21:01
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Fabrication of virus metal hybrid nanomaterials: An ideal reference for bio semiconductor
摘要： Recently, Nanotechnology has made easier utilizing plant pathogens as a potential nano-material in biomedical applications. In this research work, we have exploited a devastating plant pathogenic virus of Squash leaf curl China virus (SLCCNV), as a nano-bio template (32 nm) to fabricate the gold and silver nanomaterials. This is achieved through the direct exposure of SLCCNV to gold chloride (HAuCl4) and silver nitrate (AgNO3) precursors at sunlight, resulted into SLCCNV-metallic-hybrid nanomaterials which are synthesized quick ((cid:1)5 min) and eco-friendly. However, virus hybrid nanomaterials are fabricated through the nucleation and growth of metal precursors over the pH-activated capsid of SLCCNV. Under the controlled fabrication process, it produced a highly arrayed virus-metallic-hybrid nanomaterial at nanoscale size limit. Its properties are thoroughly studied through spectroscopic techniques (UV–Vis, DLS, Raman) and electron microscopy (HRTEM & FESEM). In a follow-up study of cytotoxicity assay, the virus and its fabricated nanomaterials show better biocompatibility features even at high concentrations. Finally, the electrical conductivities of virus-metallic-hybrid nanomaterials (Au & Ag) are determined by simple ‘‘lab on a chip” system and Keithley’s pico-ammeter. The result of electrical conductivity measurement revealed that hybrid nanomaterials have greater electrical conductive properties within the band-gap of semi-conductive materials. It is truly remarkable that a plant virus associated metal nanomaterials can be ef?ciently used as bio-semi-conductors which are the ideal one for biomedical applications.
关键词： Virus hybrid nanomaterials,Electrical conductivity,Virus template,Virus nanotechnology,Biocompatibility,Surface biomineralization
更新于2025-09-23 15:21:01
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Near-Infrared-Detached Adhesion Enabled by Upconverting Nanoparticles
摘要： Achieving efficient and biocompatible detachment between adhered wet materials (i.e., tissues and hydrogels) is a major challenge. Recently, photodetachable topological adhesion has shown great promise as a strategy for conquering this hurdle. However, this photodetachment was triggered by UV light with poor biocompatibility and penetration capacity. This study describes near-infrared (NIR) light-detached topological adhesion based on polyacrylic acid coated upconverting nanoparticles (UCNP@PAA) and a photodetachable adhesive (termed Cell-Fe). Cell-Fe is a coordinated topological adhesive consisting of carboxymethylcellulose and Fe3+ that can be photodecomposed by UV light. To prepare a substrate for NIR-detached topological adhesion, UCNP@PAA and Cell-Fe were mixed and brushed on the surface of the model adherent. The UCNP@PAA can harvest NIR light and convert it into UV light, triggering the decomposition of the Cell-Fe and inducing the detachment. This NIR-detached topological adhesion is also feasible in deep tissue because of the ability of NIR light to penetrate tissue.
关键词： upconverting nanoparticles,NIR-detached adhesion,biocompatibility,deep tissue
更新于2025-09-23 15:19:57
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Synthesis of Water Soluble CuGaS2/ZnS Quantum Dots for Ultrasensitive Fluorescent Detection of Alkaline Phosphatase Based on Inner Filter Effect
摘要： Developing monitoring technique for alkaline phosphatase (ALP) is crucial due to the important role it plays in living cells. Here, a kind of biocompatible glutathione-modified CuGaS2/ZnS quantum dots (GSH-CGS/ZnS QDs) was used as a fluorescent substance and then fabricated “turn-off” fluorescent biosensor for detection of ALP by help of inner filter effect (IFE). Firstly, we prepared CuGaS2/ZnS (CGS/ZnS) QDs using solvothermal method and explored the efficient ligand (GSH) exchanges strategy for transferring oil-soluble CGS/ZnS QDs to aqueous phase. More importantly, we also explored the potential biological applications of the nanohybrid QDs. The obtained GSH-CGS/ZnS QDs emitted strong yellow fluorescence with the maximum excitation (400 nm) and emission (601 nm). Then, GSH-CGS/ZnS QDs were mixed with p-nitrophenylphosphate (PNPP) and ALP. PNPP could be hydrolyzed to p-nitrophenol (PNP) by help of catalysis of ALP, and the excitation spectrum of the GSH-CGS/ZnS QDs overlapped well with the absorption spectrum of PNP, so the fluorescence of GSH-CGS/ZnS QDs was initially quenched via the so-called “IFE”. Finally, a novel “turn-off” biosensor for sensitive detection of ALP in the range of 0.05-10 U L -1(R2 = 0.98) with a detection limit of 0.01 U L-1 was successfully obtained. Results indicated that I-III-VI2 nanocrystals have great potential for their promising biomedical application.
关键词： Inner filter effect,Alkaline phosphatase,GSH-CuGaS2/ZnS QDs,Fluorescent detection,Water solubility and biocompatibility
更新于2025-09-23 15:19:57
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Polysaccharide enabled biogenic fabrication of pH??sensing fluorescent gold nanoclusters as a biocompatible tumor imaging probe
摘要： A biocompatible natural polysaccharide (PSP001) isolated from the fruit rind of Punica granatum was conjugated with L-cysteine (Y) to be used as a skeleton for the fabrication of fluorescent gold nanoclusters (AuNCs) represented as PSP-Y-AuNCs. With an average size of ~ 6 nm, PSP-Y-AuNCs demonstrated high quantum yield (31%), with a pH-sensitive fluorescence emission behavior. An emission maximum of 520 nm was obtained at acidic pH, which was blue shifted with increasing pH. This feature provides the possibilities for accurate ratiometric pH imaging. The PSP-Y-AuNCs not only demonstrated excellent biocompatibility with cancer cells and isolated peripheral lymphocytes and red blood cells but also demonstrated to be an active molecular imaging probe with appealing cellular uptake efficiency. The investigations with BALB/c mice further confirmed the non-toxic nature and in vivo imaging potential of the AuNCs. Estimation of the bio-distribution on solid tumor bearing syngeneic murine models revealed a tumor-targeted enhanced fluorescence emission pattern which is attributed to the pH responsive fluorescence behavior and the acidic microenvironment of the tumor. These findings were further confirmed with an impressive tumor accumulation pattern displayed in a xenograft of human cancer bearing nude mice. On account of their impressive biocompatibility and photophysical features, PSP-Y-AuNCs can exploited for the real-time fluorescence imaging of cancer tissues.
关键词： Polysaccharide,Tumor,pH ratiometry,Biocompatibility,In vivo imaging,Nanocluster,Fluorescence,Punica granatum,Gold nanoparticle
更新于2025-09-23 15:19:57
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The antibacterial effect of potassium-sodium niobate ceramics based on controlling piezoelectric properties
摘要： The implant infection is one of the most serious postsurgical complications of medical device implantation. Therefore, the development of biocompatible materials with improved antibacterial properties is of great importance. It might be a new insight to apply the intrinsic electrical properties of biomaterials to solve this problem. Here, potassium-sodium niobate piezoceramics (K0.5Na0.5NbO3, KNN) with different piezoelectric constants were prepared, and the microstructures and piezoelectric properties of these piezoceramics were evaluated. Moreover, the antibacterial effect and biocompatibility of these piezoceramics were assayed. Results showed that these piezoceramics were able to decrease the colonies of bacteria staphylococcus aureus (S. aureus), favor the rat bone marrow mesenchymal stem cells (rBMSCs) proliferation and promote the cell adhesion and spreading. The above effects were found closely related to the surface positive charges of the piezoceramics, and the sample bearing the most positive charges on its surface (sample 80KNN) had the best performance in both antibacterial effect and biocompatibility. Based on our work, it is feasible to develop biocompatible antibacterial materials by controlling piezoelectric properties.
关键词： Positive charges,Biocompatibility,Potassium-sodium niobate,Antibacterial property
更新于2025-09-23 15:19:57