Electrical Responsive Coating with a Multilayered TiO-SnO-RuO Heterostructure on Ti for Controlling Antibacterial Ability and Improving Osseointegration.

The bacterial infection and poor osseointegration of Ti implants could significantly compromise their applications in bone repair and replacement. Based on the carrier separation ability of the heterojunction and the redox reaction of pseudocapacitive metal oxides, we report an electrically responsive TiO-SnO-RuO coating with a multilayered heterostructure on a Ti implant. Owing to the band gap structure of the TiO-SnO-RuO coating, electron carriers are easily enriched at the coating surface, enabling a response to the endogenous electrical stimulation of the bone.

Facilitating Uniform Large-Scale MoS, WS Monolayers, and Their Heterostructures through van der Waals Epitaxy.

The fabrication process for the uniform large-scale MoS, WS transition-metal dichalcogenides (TMDCs) monolayers, and their heterostructures has been developed by van der Waals epitaxy (VdWE) through the reaction of MoCl or WCl precursors and the reactive gas HS to form MoS or WS monolayers, respectively. The heterostructures of MoS/WS or WS/MoS can be easily achieved by changing the precursor from WCl to MoCl once the WS monolayer has been fabricated or switching the precursor from MoCl to WCl after the MoS monolayer has been deposited on the substrate. These VdWE-grown MoS, WS monolayers, and their heterostructures have been successfully deposited on Si wafers with 300 nm SiO coating (300 nm SiO/Si), quartz glass, fused silica, and sapphire substrates using the protocol that we have developed.

Surface configuration of microarc oxidized Ti with regionally loaded chitosan hydrogel containing ciprofloxacin for improving biological performance.

The bacterial colonization and poor osseointegration of Ti implants significantly compromise their applications in load-bearing bone repair and replacement. To endorse the Ti with both excellent bioactivity and antibacterial ability, we developed a microarc oxidation coating that was modified uniformly by hydroxyapatite (HA) nanodots arrays and loaded regionally with chitosan hydrogel containing ciprofloxacin. The bonding between the HA nanodots covered coating and the chitosan hydrogel is further enhanced via silanization and chemical grafting of glutaraldehyde.

Rapid structural regulation, apatite-inducing mechanism and investigation of microwave-assisted hydrothermally treated titania coating.

Owing to the poor bioactivity of microarc oxidation (MAO) coating and the rapid activation ability of the microwave hydrothermal (MH) technique, MH treatment was applied to optimize the interface status between MAO-treated titanium and bone. In this study, consequently, new outermost layers were prepared using hydroxyapatite (HA) nanorods, HA submicron pillars or sodium titanate nanosheets. The results revealed that the NaOH concentration significantly influenced the surface structure and phase constitution of the MAO samples.

Comparative investigations of and bioactivity of titanium Ti-24Nb-4Zr-8Sn alloy before and after sandblasting and acid etching.

To avoid the failure of clinical surgery due to "stress shielding" and the loosening of an implant, a new type of alloy, Ti-24Nb-4Zr-8Sn (TNZS), with a low Young's modulus acted as a new implant material in this work. Meanwhile, the surface characteristics, MC3T3-E1 cell behavior and osseointegration of the titanium and TNZS before and after sandblasting and acid etching were studied comparatively. TNZS and Ti had the same microstructure based on the transmission electron microscopy results.

Rapid Fabrication, Microstructure, and Investigations of a High-Performance Multilayer Coating with External, Flexible, and Silicon-Doped Hydroxyapatite Nanorods on Titanium.

A high-performance multilayer coating with external, flexible, and silicon-doped hydroxyapatite (Si-HA) nanorods was designed using bionics. Plasma electrolytic oxidation (PEO) and the microwave hydrothermal (MH) method were used to rapidly deposit this multilayer coating on a titanium (Ti) substrate, applied for 5 and 10 min, respectively. The bioactive multilayer coating was composed of four layers, and the outermost layer was an external growth layer that consisted of many Si-HA nanorods with a single-crystal structure.

Tanshinone IIA promotes osteogenic differentiation of human periodontal ligament stem cells via ERK1/2-dependent Runx2 induction.

Mesenchymal stem cells (MSCs) of the dental or craniofacial origin include Human periodontal ligament stem cells (hPDLSCs), which are able to readily differentiate into osteoblasts. Tanshinone IIA (TSA) is a diterpene quinone compound that is derived from Danshen (also known as Salvia miltiorrhiza) used frequently in the context of traditional Chinese medicine (TCM). This study sought to assess how TSA affects the osteogenic differentiation of hPDLSCs.

Tough Magnetic Chitosan Hydrogel Nanocomposites for Remotely Stimulated Drug Release.

As one of important biomaterials for localized drug delivery system, chitosan hydrogel still suffer several challenges, including poor mechanical properties, passive drug release behavior and lack of remote stimuli response. To address these challenges, a facile in situ hybridization method was reported for fabricate tough magnetic chitosan hydrogel (MCH), which remotely switched drug release from passive release to pulsatile release under a low frequency alternating magnetic field (LAMF). The in situ hybridization method avoided the aggregation of magnetic nanoparticles (MNPs) in hydrogel, which simultaneously brings 416% and 265% increase in strength and elastic modulus, respectively.

The effect of applied voltages on the structure, apatite-inducing ability and antibacterial ability of micro arc oxidation coating formed on titanium surface.

The micro arc oxidation (MAO) coatings with different concentrations of Ca, P and Zn elements are successfully formed on the titanium substrate at the different applied voltages. After MAO treatment, the MAO coating exhibits the porous surface structure and composed of anatase and rutile TiO phases. Meanwhile, the average size and density of micro-pores on the MAO coatings have been modified via the adjusting the applied voltages.

Ultrahigh-yield synthesis of N-doped carbon nanodots that down-regulate ROS in zebrafish.

Oxidative damage induced by accumulation of excessive reactive oxygen species (ROS) could result in increased chronic inflammation and thus ageing and age-related diseases. Carbonaceous nanodrugs hold great promise for ameliorating age-related diseases, and it is necessary to develop ultrahigh-yield synthesis of such nanodrugs. To improve the synthetic yield (less than 50%) of carbon nanodots (CNDs), the general choice is to screen precursors.

Visual in vivo degradation of injectable hydrogel by real-time and non-invasive tracking using carbon nanodots as fluorescent indicator.

Visual in vivo degradation of hydrogel by fluorescence-related tracking and monitoring is crucial for quantitatively depicting the degradation profile of hydrogel in a real-time and non-invasive manner. However, the commonly used fluorescent imaging usually encounters limitations, such as intrinsic photobleaching of organic fluorophores and uncertain perturbation of degradation induced by the change in molecular structure of hydrogel. To address these problems, we employed photoluminescent carbon nanodots (CNDs) with low photobleaching, red emission and good biocompatibility as fluorescent indicator for real-time and non-invasive visual in vitro/in vivo degradation of injectable hydrogels that are mixed with CNDs.

UV-crosslinkable and thermo-responsive chitosan hybrid hydrogel for NIR-triggered localized on-demand drug delivery.

Innovative drug delivery technologies based on smart hydrogels for localized on-demand drug delivery had aroused great interest. To acquire smart UV-crosslinkable chitosan hydrogel for NIR-triggered localized on-demanded drug release, a novel UV-crosslinkable and thermo-responsive chitosan was first designed and synthesized by grafting with poly N-isopropylacrylamide, acetylation of methacryloyl groups and embedding with photothermal carbon. The UV-crosslinkable unit (methacryloyl groups) endowed chitosan with gelation via UV irradiation.

Microarc oxidation coating covered Ti implants with micro-scale gouges formed by a multi-step treatment for improving osseointegration.

The sub-microporous microarc oxidation (MAO) coating covered Ti implant with micro-scale gouges has been fabricated via a multi-step MAO process to overcome the compromised bone-implant integration. The as-prepared implant has been further mediated by post-heat treatment to compare the effects of -OH functional group and the nano-scale orange peel-like morphology on osseointegration. The bone regeneration, bone-implant contact interface, and biomechanical push-out force of the modified Ti implant have been discussed thoroughly in this work.

High-yield synthesis of strong photoluminescent N-doped carbon nanodots derived from hydrosoluble chitosan for mercury ion sensing via smartphone APP.

Photoluminescent carbon nanodots (CNDs) have offered considerable potential to be used in biomedical and environmental fields including live cell imaging and heavy metal ion detection due to their superior quantum emission efficiencies, ability to be functionalized using a variety of chemistries and apparent absence of toxicity. However, to date, synthetic yield of CNDs derived from biomass via hydrothermal carbonization is quite low. We report here the synthesis of nitrogen-doped carbon nanodots (N-doped CNDs) derived from hydrosoluble chitosan via hydrothermal carbonization.

Hydrosoluble, UV-crosslinkable and injectable chitosan for patterned cell-laden microgel and rapid transdermal curing hydrogel in vivo.

Natural and biodegradable chitosan with unique amino groups has found widespread applications in tissue engineering and drug delivery. However, its applications have been limited by the poor solubility of native chitosan in neutral pH solution, which subsequently fails to achieve cell-laden hydrogel at physiological pH. To address this, we incorporated UV crosslinking ability in chitosan, allowing fabrication of patterned cell-laden and rapid transdermal curing hydrogel in vivo.

Synergistic effects of surface chemistry and topologic structure from modified microarc oxidation coatings on Ti implants for improving osseointegration.

Microarc oxidation (MAO) coating containing Ca, P, Si, and Na elements on a titanium (Ti) implant has been steam-hydrothermally treated and further mediated by post-heat treatment to overcome the compromised bone-implant integration. The bone regeneration, bone-implant contact, and biomechanical push-out force of the modified Ti implants are discussed thoroughly in this work. The best in vivo performances for the steam-hydrothermally treated one is attributed to the synergistic effects of surface chemistry and topologic structure.

The effect of NaOH concentration on the steam-hydrothermally treated bioactive microarc oxidation coatings containing Ca, P, Si and Na on pure Ti surface.

The microarc oxidation (MAO) coating covered pure Ti plates are steam-hydrothermally treated in autoclaves containing NaOH solutions with different concentrations of 0, 0.001, 0.01, 0.

MC3T3-E1 cells' response and osseointegration of bioactive sphene-titanium oxide composite coatings fabricated by a hybrid technique of microarc oxidation and heat treatment on titanium.

Sphene-titanium oxide composite coatings are prepared by a hybrid technique of microarc oxidation (MAO) and heat treatment on titanium. The average roughness of the MAO coating increases after heat treatment due to the crystallization and crystal growth of the MAO coating. The wetting ability, roughness, phase composition and surface topological structure of the composite coatings have positive effects on the MC3T3-E1 cell attachment, proliferation and alkaline phosphatase activity.

MC3T3-E1 cell response of amorphous phase/TiO2 nanocrystal composite coating prepared by microarc oxidation on titanium.

Bioactive amorphous phase/TiO2 nanocrystal (APTN) composite coatings were fabricated by microarc oxidation (MAO) on Ti. The APTN coatings are composed of much amorphous phase with Si, Na, Ca, Ti and O elements and a few TiO2 nanocrystals. With increasing applied voltage, the micropore density of the APTN coating decreases and the micropore size of the APTN coating increases.

Structure, MC3T3-E1 cell response, and osseointegration of macroporous titanium implants covered by a bioactive microarc oxidation coating with microporous structure.

Macroporous Ti with macropores of 50-400 μm size is prepared by sintering Ti microbeads with different diameters of 100, 200, 400, and 600 μm. Bioactive microarc oxidation (MAO) coatings with micropores of 2-5 μm size are prepared on the macroporous Ti. The MAO coatings are composed of a few TiO2 nanocrystals and lots of amorphous phases with Si, Ca, Ti, Na, and O elements.

Osseointegration of bioactive microarc oxidized amorphous phase/TiO2 nanocrystals composited coatings on titanium after implantation into rabbit tibia.

The amorphous phase/TiO2 nanocrystals (APTN) composited coatings were prepared on Ti implants for biomedical applications. The Ti implants without and with the APTN composited coatings both do not cause any adverse effects after implantation into the rabbit tibia. The osseointegration of Ti implants after covering the APTN coatings is improved pronouncedly, greatly increasing the interface bonding strength between the implants and newly formed bones.