Osteointegration of titanium implant is sensitive to specific nanostructure morphology

Enhancing the Biological Performance of Titanium Alloy through In Situ Modulation of the Surface Nanostructure: Near-Infrared-Responsive Antibacterial Function and Osteoinductivity

The poor clinical performance of titanium and its alloy implants is mainly attributed to their lack of antibacterial ability and poor osseointegration. The key and challenge lie in how to enhance their osteoinductivity while imparting antibacterial capability. In this study, a titanium oxide metasurface with light-responsive behavior was constructed on the surface of titanium alloy using an alkaline-acid bidirectional hydrothermal method. The effects of the acid type, acid concentration, hydrothermal time, hydrothermal temperature, and subsequent heat treatments on the optical behavior of the metasurface were systematically investigated with a focus on exploring the influence of the metasurface and photodynamic reaction on the osteogenic activity of osteoblasts. Results show that the type of acid and heat treatment significantly affect the light absorption of the titanium alloy surface, with HCl and post-heat-treatment favoring redshift in the light absorption. Under 808 nm near-infrared (NIR) irradiation for 10 min, in vitro antibacterial experiments demonstrate that the antibacterial rate of the metasurface titanium alloy against Staphylococcus aureus and Escherichia coli were 96.87% and 99.27%, respectively. In vitro cell experiments demonstrate that the nanostructure facilitates cell adhesion, proliferation, differentiation, and expression of osteogenic-related genes. Surprisingly, the nanostructure promoted the expression of relevant osteogenic genes of MC3T3-E1 under 808 nm NIR irradiation. This study provides a method for the surface modification of titanium alloy implants.

Mineralization, degradation and osteogenic property of polylactide multicomponent porous composites for bone repair: In vitro and in vivo study

Gelatin and hydroxyapatite were assembled into polylactide porous matrix to prepare multicomponent porous composites for bone repair (PLA-gH). PLA-gH possessed a superior ability of mineralization. During simulated body fluids (SBF), the spherical Ca-P depositions on surface of PLA-gH became bulk as Ca/P decreased, while they locally turned into the rod with different variation in Ca/P during SBF containing bovine serum albumin (SBF-BSA), indicating that the mineralization of PLA-gH could be regulated by BSA. Meanwhile, PLA-gH possessed good degradation behaviour, especially in SBF-BSA, the degradation of PLA porous matrix was higher than that in SBF after 14-day immersion, whose crystallinity (Xc) decreased to a slightly lower level. Gelatin and hydroxyapatite endowed PLA-gH with good osteogenic property, characterized by obvious osteogenic differentiation and bone regeneration. In terms of predicting the cytocompatibility, osteogenic differentiation and new bone mineralization of PLA-gH by in vitro methods, applying SBF-BSA may be more reliable than SBF.

Preparation and Characterization of Nanofiber Coatings on Bone Implants for Localized Antimicrobial Activity Based on Sustained Ion Release and Shape-Preserving Design

Titanium (Ti), as a hard tissue implant, is facing a big challenge for rapid and stable osseointegration owing to its intrinsic bio-inertness. Meanwile, surface-related infection is also a serious threat. In this study, large-scale quasi-vertically aligned sodium titanate nanowire (SNW) arrayed coatings incorporated with bioactive Cu2+ ions were fabricated through a compound process involving acid etching, hydrothermal treatment (HT), and ion exchange (IE). A novel coating based on sustained ion release and a shape-preserving design is successfully obtained. Cu2+ substituted Na+ in sodium titanate lattice to generate Cu-doped SNW (CNW), which maintains the micro-structure and phase components of the original SNW, and can be efficiently released from the structure by immersing them in physiological saline (PS) solutions, ensuring superior long-term structural stability. The synergistic effects of the acid etching, bidirectional cogrowth, and solution-strengthening mechanisms endow the coating with higher bonding strengths. In vitro antibacterial tests demonstrated that the CNW coatings exhibited effective good antibacterial properties against both Gram-positive and Gram-negative bacteria based on the continuous slow release of copper ions. This is an exciting attempt to achieve topographic, hydrophilic, and antibacterial activation of metal implants, demonstrating a paradigm for the activation of coatings without dissolution and providing new insights into insoluble ceramic-coated implants with high bonding strengths.

Selective Laser Melting of the Porous Ta Scaffold with Mg-Doped Calcium Phosphate Coating for Orthopedic Applications

Addressing the repair of large-scale bone defects has become a hot research topic within the field of orthopedics. This study assessed the feasibility and effectiveness of using porous tantalum scaffolds to treat such defects. These scaffolds, manufactured using the selective laser melting (SLM) technology, possessed biomechanical properties compatible with natural bone tissue. To enhance the osteogenesis bioactivity of these porous Ta scaffolds, we applied calcium phosphate (CaP) and magnesium-doped calcium phosphate (Mg-CaP) coatings to the surface of SLM Ta scaffolds through a hydrothermal method. These degradable coatings released calcium and magnesium ions, demonstrating osteogenic bioactivity. Experimental results indicated that the Mg-CaP group exhibited biocompatibility comparable to that of the Ta group in vivo and in vitro. In terms of osteogenesis, both the CaP group and the Mg-CaP group showed improved outcomes compared to the control group, with the Mg-CaP group demonstrating superior performance. Therefore, both CaP and magnesium-CaP coatings can significantly enhance the osseointegration of three-dimensional-printed porous Ta, thereby increasing the surface bioactivity. Overall, the present study introduces an innovative approach for the biofunctionalization of SLM porous Ta, aiming to enhance its suitability as a bone implant material.

Screw Osteointegration-Increasing Biomechanical Resistance to Pull-Out Effect

Spinal disorders cover a broad spectrum of pathologies and are among the most prevalent medical conditions. The management of these health issues was noted to be increasingly based on surgical interventions. Spinal fixation devices are often employed to improve surgery outcomes, increasing spinal stability, restoring structural integrity, and ensuring functionality. However, most of the currently used fixation tools are fabricated from materials with very different mechanical properties to native bone that are prone to pull-out effects or fail over time, requiring revision procedures. Solutions to these problems presently exploited in practice include the optimal selection of screw shape and size, modification of insertion trajectory, and utilization of bone cement to reinforce fixation constructs. Nevertheless, none of these methods are without risks and limitations. An alternative option to increasing biomechanical resistance to the pull-out effect is to tackle bone regenerative capacity and focus on screw osteointegration properties. Osteointegration was reportedly enhanced through various optimization strategies, including use of novel materials, surface modification techniques (e.g., application of coatings and topological optimization), and utilization of composites that allow synergistic effects between constituents. In this context, this paper takes a comprehensive path, starting with a brief presentation of spinal fixation devices, moving further to observations on how the pull-out strength can be enhanced with existing methods, and further focusing on techniques for implant osteointegration improvement.

Nanoscale Morphologies on the Surface of 3D-Printed Titanium Implants for Improved Osseointegration: A Systematic Review of the Literature

Three-dimensional (3D) printing is serving as the most promising approach to fabricate personalized titanium (Ti) implants for the precise treatment of complex bone defects. However, the bio-inert nature of Ti material limits its capability for rapid osseointegration and thus influences the implant lifetime in vivo. Despite the macroscale porosity for promoting osseointegration, 3D-printed Ti implant surface morphologies at the nanoscale have gained considerable attention for their potential to improve specific outcomes. To evaluate the influence of nanoscale surface morphologies on osseointegration outcomes of 3D-printed Ti implants and discuss the available strategies, we systematically searched evidence according to the PRISMA on PubMed, Embase, Web of Science, and Cochrane (until June 2022). The inclusion criteria were in vivo (animal) studies reporting the osseointegration outcomes of nanoscale morphologies on the surface of 3D-printed Ti implants. The risk of bias (RoB) was assessed using the Systematic Review Centre for Laboratory Animal Experimentation (SYRCLE's) tool. The quality of the studies was evaluated using the Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines. (PROSPERO: CRD42022334222). Out of 119 retrieved articles, 9 studies met the inclusion criteria. The evidence suggests that irregular nano-texture, nanodots and nanotubes with a diameter of 40-105nm on the surface of porous/solid 3D-printed Ti implants result in better osseointegration and vertical bone ingrowth compared to the untreated/polished ones by significantly promoting cell adhesion, matrix mineralization, and osteogenic differentiation through increasing integrin expression. The RoB was low in 41.1% of items, unclear in 53.3%, and high in 5.6%. The quality of the studies achieved a mean score of 17.67. Our study demonstrates that nanostructures with specific controlled properties on the surface of 3D-printed Ti implants improve their osseointegration. However, given the small number of studies, the variability in experimental designs, and lack of reporting across studies, the results should be interpreted with caution.

Branched Amphiphilic Polylactides as a Polymer Matrix Component for Biodegradable Implants

The combination of biocompatibility, biodegradability, and high mechanical strength has provided a steady growth in interest in the synthesis and application of lactic acid-based polyesters for the creation of implants. On the other hand, the hydrophobicity of polylactide limits the possibilities of its use in biomedical fields. The ring-opening polymerization of L-lactide, catalyzed by tin (II) 2-ethylhexanoate in the presence of 2,2-bis(hydroxymethyl)propionic acid, and an ester of polyethylene glycol monomethyl ester and 2,2-bis(hydroxymethyl)propionic acid accompanied by the introduction of a pool of hydrophilic groups, that reduce the contact angle, were considered. The structures of the synthesized amphiphilic branched pegylated copolylactides were characterized by ¹H NMR spectroscopy and gel permeation chromatography. The resulting amphiphilic copolylactides, with a narrow MWD (1.14-1.22) and molecular weight of 5000-13,000, were used to prepare interpolymer mixtures with PLLA. Already, with the introduction of 10 wt% branched pegylated copolylactides, PLLA-based films had reduced brittleness, hydrophilicity, with a water contact angle of 71.9-88.5°, and increased water absorption. An additional decrease in the water contact angle, of 66.1°, was achieved by filling the mixed polylactide films with 20 wt% hydroxyapatite, which also led to a moderate decrease in strength and ultimate tensile elongation. At the same time, the PLLA modification did not have a significant effect on the melting point and the glass transition temperature; however, the filling with hydroxyapatite increased the thermal stability.

Mechanical, Structural, and Biological Characteristics of Polylactide/Wollastonite 3D Printed Scaffolds

The present work aimed to study the synergistic response of bioresorbable polylactide/bioactive wollastonite scaffolds towards mechanical stability, mesenchymal stromal cell colonization, and antibacterial activity in the physiological environment. Wollastonite was synthesized at 800 °C within 2 h by sol-gel combustion method. The surface area was found to be 1.51 m²/g, and Transmission Electron Microscopy (TEM) micrographs indicated the presence of porous structures. Fused deposition modeling was used to prepare 3D-printed polylactide/wollastonite and polylactide/hydroxyapatite scaffolds. Scanning Electron Microscopy (SEM) micrographs confirmed the interconnected porous structure and complex geometry of the scaffolds. The addition of wollastonite decreased the contact angle of the scaffolds. The mechanical testing of scaffolds examined by computational simulation, as well as machine testing, revealed their non-load-bearing capacity. The chemical constituent of the scaffolds was found to influence the attachment response of different cells on their surface. The incorporation of wollastonite effectively reduced live bacterial attachment, whereas the colonization of mesenchymal cells was improved. This observation confirms polylactide/wollastonite scaffold possesses both bactericidal as well as cytocompatible properties. Thus, the risk of peri-implant bacterial film formation can be prevented, and the biological fixation of the scaffold at the defect site can be enhanced by utilizing these composites.

Synergistic effect of nanostructure and calcium ions on improving the bioactivity of titanium implants

Surface structure and composition play essential roles in the osseointegration of titanium implants. In the present study, a nanoscale surface structure incorporated with calcium ions was fabricated on a titanium surface by hydrothermal treatment. The characteristics of the surfaces were analysed, and the bioactivity of the samples was evaluated in vitro and in vivo. nm-Ti and nm/Ca-Ti surfaces were significantly more hydrophilic than control-Ti surfaces. nm/Ca-Ti samples showed much faster bone-like apatite precipitation in simulated body fluid than the other samples. The results of MC3T3-E1 cell tests demonstrated that both nm-Ti and nm/Ca-Ti surfaces accelerated cell adhesion and proliferation. The highest level of osteogenesis-related genes (Runx2, bone morphogenetic protein-2, osteopontin and osteocalcin) were observed in nm/Ca-Ti samples, followed by nm-Ti samples. Alizarin red staining experiment showed that the amount of extracellular matrix mineralized nodules in nm/Ca-Ti group was significantly higher than others. In animal experiments using SD rats, nm/Ca-Ti showed the highest value of new bone formation at two and four weeks. The present study suggested that the nanostructure and calcium ions showed synergetic effects on accelerating bone-like apatite precipitation and osteoblast cell growth and differentiation. Animal experiment further indicated that such surface could promote early osteogenesis.

Synergistic effect of nanostructure and calcium ions on improving the bioactivity of titanium implants

Surface structure and composition play essential roles in the osseointegration of titanium implants. In the present study, a nanoscale surface structure incorporated with calcium ions was fabricated on a titanium surface by hydrothermal treatment. The characteristics of the surfaces were analysed, and the bioactivity of the samples was evaluated in vitro and in vivo. nm-Ti and nm/Ca-Ti surfaces were significantly more hydrophilic than control-Ti surfaces. nm/Ca-Ti samples showed much faster bone-like apatite precipitation in simulated body fluid than the other samples. The results of MC3T3-E1 cell tests demonstrated that both nm-Ti and nm/Ca-Ti surfaces accelerated cell adhesion and proliferation. The highest level of osteogenesis-related genes (Runx2, bone morphogenetic protein-2, osteopontin and osteocalcin) were observed in nm/Ca-Ti samples, followed by nm-Ti samples. Alizarin red staining experiment showed that the amount of extracellular matrix mineralized nodules in nm/Ca-Ti group was significantly higher than others. In animal experiments using SD rats, nm/Ca-Ti showed the highest value of new bone formation at two and four weeks. The present study suggested that the nanostructure and calcium ions showed synergetic effects on accelerating bone-like apatite precipitation and osteoblast cell growth and differentiation. Animal experiment further indicated that such surface could promote early osteogenesis.

The role of NiTi shape memory alloys in quality of life improvement through medical advancements: A comprehensive review

The significance of advanced smart materials in recent technological research and advancement is apparent from its extensive use in present day devices and instruments. Of the various smart materials in use today, the fascinating category of shape memory alloys (SMAs) is equipped with the ability to return to a previously memorized shape under certain thermomechanical or magnetic stimuli. The unique property of shape memory effect and superelasticity displayed by these materials along with good biocompatibility and corrosion resistance make them ideal for biomedical applications. The various applications of SMAs in surgical instruments, surgical implants, and assistive and rehabilitative devices have significant effect on the day to day life of people in the present age. Majority of these biomedical devices belong to the orthodontic, orthopedic, or surgical fields. Other remarkable applications of SMAs such as in the production of prostheses and orthoses designed through the biomimetic approach are also highly influential in improving the quality of life. The present paper provides an overview of the various properties of shape memory alloys and their applications in the biomedical field over the years, that have had a significant impact on the realm of medical science.

Influence of Indium (III) Chloride on Human Dermal Fibroblast Cell Adhesion on Tantalum/Silicon Oxide Nano-Composites

Cell adhesion is an essential biological function for division, migration, signaling and tissue development. While it has been demonstrated that this cell function can be modified by using nanometer-scale surface topographic structures, it remains unknown how contaminants such as indium (III) ion might influence this specific cell behavior. Herein, the influence of indium chloride on human dermal fibroblast (GM5565) adhesion characteristics was investigated, given the frequent contact of contaminants with skin. The morphology of the adherent cells and their mitochondrial reticulum was characterized on cell culture dishes and nanopatterned surfaces by using fluorescence confocal microscopy and scanning electron microscopy. Results showed a significant proportion of cells lost their ability to align preferentially along the line axes of the nanopattern upon exposure to 3.2 mM indium chloride, with cells aligned within 10° of the pattern line axes reduced by as much as ~70%. Concurrent with the cell adhesion behaviors, the mitochondria in cells exposed to indium chloride exhibit a punctate staining that contrasts with the normal network of elongated tubular geometry seen in control cells. Our results demonstrate that exposure to indium chloride has detrimental effects on the behavior of human fibroblasts and adversely impacts their mitochondrial morphology. This shows the importance of evaluating the biological impacts of indium compounds.

Surface Modification Techniques to Produce Micro/Nano-scale Topographies on Ti-Based Implant Surfaces for Improved Osseointegration

Titanium and titanium alloys are used as artificial bone substitutes due to the good mechanical properties and biocompatibility, and are widely applied in the treatment of bone defects in clinic. However, Pure titanium has stress shielding effect on bone, and the effect of titanium-based materials on promoting bone healing is not significant. To solve this problem, several studies have proposed that the surface of titanium-based implants can be modified to generate micro or nano structures and improve mechanical properties, which will have positive effects on bone healing. This article reviews the application and characteristics of several titanium processing methods, and explores the effects of different technologies on the surface characteristics, mechanical properties, cell behavior and osseointegration. The future research prospects in this field and the characteristics of ideal titanium-based implants are proposed.

Superhydrophilic multifunctional nanotextured titanium dental implants: in vivo short and long-term response in a porcine model

Current clinical demand in dental implantology is for a multifunctional device with optimum mechanical properties, improved biocompatibility and bioactivity, and having differential interactions with cells and pathogenic agents. This would minimise bacterial infection, biofilm formation and modulate inflammation, leading to a fast and durable osseointegration. The present study intends to establish the multifunctional behaviour of surface modified titanium dental implants that are superhydrophilic, with unique micro-nano or nanoscale topographies, developed by a facile hydrothermal technique. Here, the short and long-term performances of these textured implants are tested in a split mouth design using a porcine model, in pre- and post-loaded states. Quantitative and qualitative analyses of the bone implant interphase are performed through μ-CT and histology. Parameters that evaluate bone mineral density, bone contact volume and bone implant contact reveal enhanced bone apposition with better long-term response for the nano and micro-nano textured surfaces, compared to the commercial microtextured implant. Concurrently, the nanoscale surface features on implants reduced bacterial attachment by nearly 90% in vivo, outperforming the commercial variant. This preclinical evaluation data thus reveal the superiority of nano/micro-nano textured designs for clinical application and substantiate their improved osseointegration and reduced bacterial adhesion, thus proposing a novel dental implant with multifunctional characteristics.

Microbial Decontamination and Antibacterial Activity of Nanostructured Titanium Dental Implants: A Narrative Review

Peri-implantitis is the major cause of the failure of dental implants. Since dental implants have become one of the main therapies for teeth loss, the number of patients with peri-implant diseases has been rising. Like the periodontal diseases that affect the supporting tissues of the teeth, peri-implant diseases are also associated with the formation of dental plaque biofilm, and resulting inflammation and destruction of the gingival tissues and bone. Treatments for peri-implantitis are focused on reducing the bacterial load in the pocket around the implant, and in decontaminating surfaces once bacteria have been detached. Recently, nanoengineered titanium dental implants have been introduced to improve osteointegration and provide an osteoconductive surface; however, the increased surface roughness raises issues of biofilm formation and more challenging decontamination of the implant surface. This paper reviews treatment modalities that are carried out to eliminate bacterial biofilms and slow their regrowth in terms of their advantages and disadvantages when used on titanium dental implant surfaces with nanoscale features. Such decontamination methods include physical debridement, chemo-mechanical treatments, laser ablation and photodynamic therapy, and electrochemical processes. There is a consensus that the efficient removal of the biofilm supplemented by chemical debridement and full access to the pocket is essential for treating peri-implantitis in clinical settings. Moreover, there is the potential to create ideal nano-modified titanium implants which exert antimicrobial actions and inhibit biofilm formation. Methods to achieve this include structural and surface changes via chemical and physical processes that alter the surface morphology and confer antibacterial properties. These have shown promise in preclinical investigations.

Local and Systemic In Vivo Responses to Osseointegrative Titanium Nanotube Surfaces

Orthopedic implants requiring osseointegration are often surface modified; however, implants may shed these coatings and generate wear debris leading to complications. Titanium nanotubes (TiNT), a new surface treatment, may promote osseointegration. In this study, in vitro (rat marrow-derived bone marrow cell attachment and morphology) and in vivo (rat model of intramedullary fixation) experiments characterized local and systemic responses of two TiNT surface morphologies, aligned and trabecular, via animal and remote organ weight, metal ion, hematologic, and nondecalcified histologic analyses. In vitro experiments showed total adherent cells on trabecular and aligned TiNT surfaces were greater than control at 30 min and 4 h, and cells were smaller in diameter and more eccentric. Control animals gained more weight, on average; however, no animals met the institutional trigger for weight loss. No hematologic parameters (complete blood count with differential) were significantly different for TiNT groups vs. control. Inductively coupled plasma mass spectrometry (ICP-MS) showed greater aluminum levels in the lungs of the trabecular TiNT group than in those of the controls. Histologic analysis demonstrated no inflammatory infiltrate, cytotoxic, or necrotic conditions in proximity of K-wires. There were significantly fewer eosinophils/basophils and neutrophils in the distal region of trabecular TiNT-implanted femora; and, in the midshaft of aligned TiNT-implanted femora, there were significantly fewer foreign body giant/multinucleated cells and neutrophils, indicating a decreased immune response in aligned TiNT-implanted femora compared to controls.

Rapid structural regulation, apatite-inducing mechanism and in vivo 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 in vivo 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. Moreover, on enhancing the NaOH concentration, the number of HA phases was decreased. Further, the influence of the NaOH concentration on the interfacial bonding strength was insignificant for concentrations ≤0.5 mol L⁻¹. Transmission electron microscopy (TEM) analysis showed that the induction of apatite was accompanied by the dissolution of the HA crystals and there was excellent crystallographic matching with the HA crystals. The in vitro and in vivo analyses revealed that the MH-treated MAO sample with the HA nanorods possessed superior apatite-formation ability and osseointegration, including a small amount of soft tissue and optimal bone–implant interfacial bonding force, thus signifying strong potential for the optimization of the bone–implant interfacial status.

In this work, the micro/nano scale structures of HA nanorods integrated on a titanium were prepared using MAO and MH treatment. The in vivo results indicate that HA crystals play a crucial role in the improvement of the osseointegration.

Synergistic antibacterial activity of physical-chemical multi-mechanism by TiO2 nanorod arrays for safe biofilm eradication on implant

Treatment of implant-associated infection is becoming more challenging, especially when bacterial biofilms form on the surface of the implants. Developing multi-mechanism antibacterial methods to combat bacterial biofilm infections by the synergistic effects are superior to those based on single modality due to avoiding the adverse effects arising from the latter. In this work, TiO2 nanorod arrays in combination with irradiation with 808 near-infrared (NIR) light are proven to eradicate single specie biofilms by combining photothermal therapy, photodynamic therapy, and physical killing of bacteria. The TiO2 nanorod arrays possess efficient photothermal conversion ability and produce a small amount of reactive oxygen species (ROS). Physiologically, the combined actions of hyperthermia, ROS, and puncturing by nanorods give rise to excellent antibacterial properties on titanium requiring irradiation for only 15 min as demonstrated by our experiments conducted in vitro and in vivo. More importantly, bone biofilm infection is successfully treated efficiently by the synergistic antibacterial effects and at the same time, the TiO2 nanorod arrays improve the new bone formation around implants. In this protocol, besides the biocompatible TiO2 nanorod arrays, an extra photosensitizer is not needed and no other ions would be released. Our findings reveal a rapid bacteria-killing method based on the multiple synergetic antibacterial modalities with high biosafety that can be implemented in vivo and obviate the need for a second operation. The concept and antibacterial system described here have large clinical potential in orthopedic and dental applications.

Biocompatibility and Physico-Chemical Properties of Highly Porous PLA/HA Scaffolds for Bone Reconstruction

The major problem in bone tissue engineering is the development of scaffolds which can simultaneously meet the requirements of porous structure, as well as have the ability to guide the regeneration of damaged tissue by biological fixation. Composites containing biodegradable matrix and bioactive filler are the new hope in this research field. Herein we employed a simple and facile solvent casting particulate-leaching method for producing polylactide acid/hydroxyapatite (PLA/HA) composites at room temperature. FT-IR analysis confirmed the existence of necessary functional groups associated with the PLA/HA composite, whereas energy-dispersive X-ray (EDX) spectra indicated the uniform distribution of hydroxyapatite particles in the polymer matrix. The beehive-like surface morphology of the composites revealed the presence of macropores, ranged from 300 to 400 μm, whereas the thickness of the pores was noticed to be 1-2 μm. The total porosity of the scaffolds, calculated by hydrostatic weighing, was found to be 79%. The water contact angle of pure PLA was decreased from 83.6 ± 1.91° to 62.4 ± 4.17° due to the addition of hydroxyapatite in the polymer matrix. Thus, the wettability of the polymeric biomaterial could be increased by preparing their composites with hydroxyapatite. The adhesion of multipotent mesenchymal stromal cells over the surface of PLA/HA scaffolds was 3.2 times (p = 0.03) higher than the pure PLA sample. Subcutaneous implantation in mice demonstrated a good tolerance of all tested porous scaffolds and widespread ingrowth of tissue into the implant pores. HA-containing scaffolds showed a less pronounced inflammatory response after two weeks of implantation compared to pure PLA. These observations suggest that PLA/HA composites have enormous potential for hard tissue engineering and restoring maxillofacial defects.

The Fabrication and Function of Strontium-modified Hierarchical Micro/Nano Titanium Implant

Background

Relying on surface topography alone to enhance the osteointegration of implants is still inadequate. An effective way to combine long-term ion release and surface topography to enhance osteogenic property is urgently needed.

Purpose

The objective of this study is to fabricate a long-term strontium ion release implant system and confirm the biological function in vitro and in vivo.

Methods

The biomimic surface was fabricated through alkali-heat treatment and magnetron sputtering. The in vitro biological function assays were determined by MTT, fluorescence staining, alkaline phosphatase activity, extracellular mineralization, and quantitative real-time polymerase chain reaction assays. The in vivo experiments were detected by micro-CT, HE staining and Masson staining.

Results

The biomimic surface structure has been successfully fabricated. The in vitro cell assays determined that AH-Ti/Sr90 possessed the best biological function. The in vivo experiments demonstrated that AH-Ti/Sr90 could promote osteointegration significantly under both in normal and osteoporotic conditions.

Conclusion

We determined that AH-Ti/Sr90 possesses the best osteogenic property, long-term ion release capacity and osteointegration promotion ability. It has potential clinic application prospects.

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Influence of Nanotopography on Early Bone Healing during Controlled Implant Loading

Nanoscale surface modifications influence peri-implant cell fate decisions and implant loading generates local tissue deformation, both of which will invariably impact bone healing. The objective of this study is to determine how loading affects healing around implants with nanotopography. Implants with a nanoporous surface were placed in over-sized osteotomies in rat tibiae and held stable by a system that permits controlled loading. Three regimens were applied: (a) no loading, (b) one daily loading session with a force of 1.5N, and (c) two such daily sessions. At 7 days post implantation, animals were sacrificed for histomorphometric and DNA microarray analyses. Implants subjected to no loading or only one daily loading session achieved high bone-implant contact (BIC), bone-implant distance (BID) and bone formation area near the implant (BFAt) values, while those subjected to two daily loading sessions showed less BFAt and BIC and more BID. Gene expression profiles differed between all groups mainly in unidentified genes, and no modulation of genes associated with inflammatory pathways was detected. These results indicate that implants with nanotopography can achieve a high level of bone formation even under micromotion and limit the inflammatory response to the implant surface.

Novel Bionic Topography with MiR-21 Coating for Improving Bone-Implant Integration through Regulating Cell Adhesion and Angiogenesis

Implant loosening is still the major form of the failure of artificial joints. Herein, inspired by the operculum of the river snail, we prepared a novel bionic micro/nanoscale topography on a titanium surface. This bionic topography promoted early cell adhesion through up-regulating the expression of ITG α5β1 and thus accelerated the following cell spreading, proliferation, and differentiation. Moreover, a miR-21 coating, which promoted the angiogenic differentiation of MSCs, was fabricated on the bionic topography. Benefiting from both bionic micro/nanoscale topography and miR-21, blood vessel growth and bone formation and mineralization around the implant, as well as bone-implant bonding strength, were significantly improved. Collectively, the present study highlights the combination of the bionic micro/nanoscale topography and miR-21 on promoting cell adhesion and angiogenic differentiation and improving in vivo angiogenesis and bone-implant osseointegration. This work provides a new train of thought propelling the development of implants for potential application in the orthopedics field.

In vitro bioactivity of AH plus with the addition of nano-magnesium hydroxide

Background

AH Plus (AH) has been widely used as a root canal sealer in the endodontic field due to its superior physicochemical properties. However, clinical application of AH is limited due to its weak bioactivity.

Methods

In this study, we have developed an AH cement containing nano-magnesium hydroxide (NMH) as an additive to enhance the bioactivity of AH. The NMH can neutralize pH and facilitate bone formation. The objective of this study was to evaluate the effects of NMH and modified AH on osteoblasts behavior in vitro. The CCK-8, alkaline phosphatase (ALP) staining, and real-time polymerase chain reaction (PCR) assays were used to assess the proliferation and differentiation of MC3T3-E1 cells, respectively. The adhesion and spreading of MC3T3-E1 cells were investigated in vitro by scanning electron microscopy (SEM). Meanwhile, the flow and magnesium ion release of the modified AH was also concerned.

Results

In vitro cell assays further showed that the addition of NMH into AH cement, which was denoted as modified AH (especially AH+3%NMH), could effectively improve the proliferation and osteogenic differentiation of MC3T3-E1 cells.

Conclusions

Taken all together, we believe that the modified AH samples (especially AH+3%NMH) have outstanding biocompatibility and osteogenic properties and may have great potential in endodontic field.

Icariin/Aspirin Composite Coating on TiO2 Nanotubes Surface Induce Immunomodulatory Effect of Macrophage and Improve Osteoblast Activity

Surface coating modification of titanium-based alloys is an efficient way to accelerate early osseointegration in dental implant fields. Icariin (ICA) is a traditional Chinese medicine that has bone activating functions, while aspirin (ASP) is a classical non-steroidal anti-inflammatory drug with good antipyretic and analgesic capabilities. Moreover, poly(lactic–co–glycolic acid) (PLGA) has attracted great attention due to its excellent biocompatibility and biodegradability. We superimposed an ASP/PLGA coating onto ICA loaded TiO2 nanotubes structure so as to establish an icariin/aspirin composite coating on TiO2 nanotubes surface. Scanning electron microscopy, X-ray photoelectron spectroscopy, a contact angle test and a drug release test confirmed the successful preparation of the NT–ICA–ASP/PLGA substrate, with a sustained release pattern of both ICA and ASP. Compared to those cultured on the Ti surface, macrophage cells on the NT-ICA-ASP/PLGA substrate displayed decreased M1 proinflammatory and enhanced M2 proregenerative genes and proteins expression, which implied activated immunomodulatory effect. Moreover, when cultured with conditioned medium from macrophages, osteoblast cells on the NT-ICA-ASP/PLGA substrate revealed improved cell proliferation, adhesion and osteogenic genes and proteins expression, compared with those on the Ti surface. The abovementioned results suggest that the established NT-ICA-ASP/PLGA substrate is a promising candidate for functionalized coating material in Ti implant surface modification.

Osteo-Compatibility of 3D Titanium Porous Coating Applied by Direct Energy Deposition (DED) for a Cementless Total Knee Arthroplasty Implant: in Vitro and in Vivo Study

Direct energy deposition (DED) technology has gained increasing attention as a new implant surface technology that replicates the porous structure of natural bones facilitating osteoblast colonization and bone ingrowth. However, concerns have arisen over osteolysis or chronic inflammation that could be caused by Cobalt-chrome (CoCr) alloy and Titanium (Ti) nanoparticles produced during the fabrication process. Here, we evaluated whether a DED Ti-coated on CoCr alloy could improve osteoblast colonization and osseointegration in vitro and in vivo without causing any significant side effects. Three types of implant CoCr surfaces (smooth, sand-blasted and DED Ti-coated) were tested and compared. Three cell proliferation markers and six inflammatory cytokine markers were measured using SaOS2 osteoblast cells. Subsequently, X-ray and bone histomorphometric analyses were performed after implantation into rabbit femur. There were no differences between the DED group and positive control in cytokine assays. However, in the 5-bromo-2′-deoxyuridine (BrdU) assay the DED group exhibited even higher values than the positive control. For bone histomorphometry, DED was significantly superior within the 1000 µm bone area. The results suggest that DED Ti-coated metal printing does not affect the osteoblast viability or impair osseointegration in vitro and in vivo. Thus, this technology is biocompatible for coating the surfaces of cementless total knee arthroplasty (TKA) implants.

Optimized Nanointerface Engineering of Micro/Nanostructured Titanium Implants to Enhance Cell-Nanotopography Interactions and Osseointegration

The success of orthopedic implants requires rapid and complete osseointegration which relies on an implant surface with optimal features. To enhance cellular function in response to the implant surface, micro- and nanoscale topography have been suggested as essential. The aim of this study was to identify an optimized Ti nanostructure and to introduce it onto a titanium plasma-sprayed titanium implant (denoted NTPS-Ti) to confer enhanced immunomodulatory properties for optimal osseointegration. To this end, three types of titania nanostructures, namely, nanowires, nanonests, and nanoflakes, were achieved on hydrothermally prepared Ti substrates. The nanowire surface modulated protein conformation and directed integrin binding and specificity in such a way as to augment the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and induce a desirable osteoimmune response of RAW264.7 macrophages. In a coculture system, BMSCs on the optimized micro/nanosurface exerted enhanced effects on nonactivated or lipopolysaccharide-stimulated macrophages, causing them to adopt a less inflammatory macrophage profile. The enhanced immunomodulatory properties of BMSCs grown on NTPS-Ti depended on a ROCK-medicated cyclooxygenase-2 (COX2) pathway to increase prostaglandin E2 (PGE2) production, as evidenced by decreased production of PGE2 and concurrent inhibition of immunomodulatory properties after treatment with ROCK or COX2 inhibitors. In vivo evaluation showed that the NTPS-Ti implant resulted in enhanced osseointegration compared with the TPS-Ti and Ti implants. The results obtained in our study may provide a prospective approach for enhancing osseointegration and supporting the application of micro/nanostructured Ti implants.

Mesenchymal stem cell interaction with Ti6Al4V alloy pre-exposed to simulated body fluid

Titanium and its alloys are widely used for substitution of hard tissues, especially in orthopaedic and dental surgery. Despite the benefit of the use of titanium for such applications, there are still questions which must be sorted out. Surface properties are crucial for cell adhesion, proliferation and differentiation. Mainly, micro/nanostructured surfaces positively influence osteogenic differentiation of human mesenchymal stem cells. Ti₆Al₄V is a biocompatible α + β alloy which is widely used in orthopaedics. The aim of this study was to investigate the interaction of the nanostructured and ground Ti₆Al₄V titanium alloys with simulated body fluid complemented by the defined precipitation of hydroxyapatite-like coating and to study the cytotoxicity and differentiation capacity of cells with such a modified titanium alloy. Nanostructures were fabricated using electrochemical oxidation. Human mesenchymal stem cells (hMSC) were used to evaluate cell adhesion, metabolic activity and proliferation on the specimens. The differentiation potential of the samples was investigated using PCR and specific staining of osteogenic markers collagen type I and osteocalcin. Our results demonstrate that both pure Ti₆Al₄V, nanostructured samples, and hydroxyapatite-like coating supported hMSC growth and metabolic activity. Nanostructured samples improved collagen type I synthesis after 14 days, while both nanostructured and hydroxyapatite-like coated samples enhanced collagen synthesis on day 21. Osteocalcin synthesis was the most enhanced by hydroxyapatite-like coating on the nanostructured surfaces. Our results indicate that hydroxyapatite-like coating is a useful tool guiding hMSC osteogenic differentiation.

Titanium and its alloys are widely used for substitution of hard tissues, especially in orthopaedic and dental surgery.

Rapid Fabrication, Microstructure, and in Vitro and in Vivo 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. The Si-HA nanorods exhibited good flexibility, likely because of their complete single-crystal structures, smooth surfaces, and suitable diameters and lengths. This multilayer coating with a high surface energy was superhydrophilic and exhibited good in vitro bioactivities, such as good apatite formation ability, good cell spreading, and high osteogenic gene expression levels. After implantation in the tibia of rabbits for 16 weeks, almost no soft tissues were formed at the MH treated PEO implant-bone interface. A direct bone contact interface was formed by a bridging effect of the flexible Si-HA nanorods, which further produced a high implant-bone interface bonding strength. The current results demonstrated that the bioactive multilayer layers with the flexible Si-HA nanorods displayed a very good osseointegration ability, showing promising applications in the biomedical field.

Chitosan/hydroxyapatite modified carbon/carbon composites: synthesis, characterization and in vitro biocompatibility evaluation

Carbon/carbon composite (C/C), due to its bio-inert property, is prone to cause bone consolidation defects and bacterial infections in clinical applications. Therefore, there is a great demand in practical applications to prevent implant infections and enhance its bone consolidation capability. In this study, we have developed a facile approach to construct a chitosan/hydroxyapatite composite modified layer on C/C surface by electrochemical deposition and a covalent grafting technique, and the modified layer has both the antibacterial activity of chitosan (CS) and the bioactivity of hydroxyapatite (HAP). The microstructure and chemical composition of the modified layer were analyzed using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and water contact angle measurements. The biological properties of the composites were evaluated using cell culture, antimicrobial test and real-time quantitative PCR in vitro. The results showed that the CS/HAP modified C/C exhibited excellent biocompatibility, bacteriostasis and osteoinductive ability. These properties are beneficial for the potential application of the modified C/C composite as a bone tissue replacement material.

Carbon/carbon composite (C/C), due to its bio-inert property, is prone to cause bone consolidation defects and bacterial infections in clinical applications.

Icariin-Functionalized Coating on TiO2 Nanotubes Surface to Improve Osteoblast Activity In Vitro and Osteogenesis Ability In Vivo

Surface modification of titanium is encouraged to facilitate early osseointegration in dental and orthopedic fields. Icariin is the main active constituents of Herba Epimedii, which has good bone-promoting ability. We established an icariin-functionalized coating composed of icariin and poly (lactic-co-glycolic acid) (PLGA) on TiO2 nanotubes surface (NT-ICA-PLGA) to promote osteoblast cell activity and early osseointegration. Surface topography, wettability and drug release pattern of the established NT-ICA-PLGA surface were characterized by scanning electron microscopy (SEM), contact angle test and drug release test. MC3T3-E1 osteoblast cell activity tests were performed using SEM, immunofluorescent staining, cell counting kit-8 and alkaline phosphatase assays. The osteogenic effects of different surfaces were observed using a rat model. Surface characterization proved the successful fabrication of the icariin-functionalized coating on the TiO2 nanotube structure, with increased wettability. The NT-ICA-PLGA substrate showed sustained release of icariin until two weeks. Osteoblast cells grown on the NT-ICA-PLGA substrate displayed improved cell adhesion, proliferation and differentiation ability than the control Ti surface. The in vivo experiment also revealed superior bone forming ability on the NT-ICA-PLGA surface, compared to the pure Ti control. These results imply that the developed NT-ICA-PLGA substrate has a promising future use as functionalized coating for implant surface modification.

Anodic formation and biomedical properties of hafnium-oxide nanofilms

Hafnium dioxide (HfO₂) is attracting attention for bio-related applications due to its good cytocompatibility, high density, and resistance to corrosion and mechanical damage. Here we synthesize two types of hafnium-oxide thin films on substrates via self-organized electrochemical anodization: (1) an array of hierarchically structured nanorods anchored to a thin oxide layer and (2) a microscopically flat oxide film. The nanostructured film is composed of a unique mixture of HfO₂, suboxide Hf₂O₃, and oxide-hydroxide compound HfO₂·nH₂O whereas the flat film is mainly HfO₂. In vitro interaction of the two films with MG-63 osteoblast-like cells and Gram-negative E. coli bacteria is studied for the first time to assess the potential of the films for biomedical application. Both films reveal good cytocompatibility and affinity for proteins, represented by fibronectin and especially albumin, which is absorbed in a nine times larger amount. The morphology and specific surface chemistry of the nanostructured film cause a two-fold enhanced antibacterial effect, better cell attachment, significantly improved proliferation of cells, five-fold rise in the cellular Young's modulus, slightly stronger production of reactive oxygen species, and formation of cell clusters. Compared with the flat film, the nanostructured one features the weakening of AFM-measured adhesion force at the cell/surface interface, probably caused by partially lifting the nanorods from the substrate due to the strong contact with cells. The present findings deepen the understanding of biological processes at the living cell/metal-oxide interface, underlying the role of surface chemistry and the impact of nanostructuring at the nanoscale.

Bacteria Death and Osteoblast Metabolic Activity Correlated to Hydrothermally Synthesised TiO₂ Surface Properties

Orthopaedic surgery comes with an inherent risk of bacterial infection, prolonged antibiotic therapy and revision surgery. Recent research has focused on nanostructured surfaces to improve the bactericidal and osseointegrational properties of implants. However, an understanding of the mechanical properties of bactericidal materials is lacking. In this work, the surface properties of hydrothermal TiO₂ nanostructured surfaces are investigated for their effect on bactericidal efficiency and cellular metabolic activity of human osteoblast cells. TiO₂ nanostructures, approximately 307 nm in height and 14 GPa stiffness, were the most effective structures against both gram-positive (Staphylococcus aureus) and gram-negative (Pseudomonas aeruginosa) bacteria. Statistical analysis significantly correlated structure height to the death of both bacteria strains. In addition, the surface contact angle and Young’s modulus were correlated to osteoblast metabolic activity. Hydrophilic surfaces with a contact angle between 35 and 50° produced the highest cellular metabolic activity rates after 24 h of incubation. The mechanical tests showed that nanostructures retain their mechanical stability and integrity over a long time-period, reaffirming the surfaces’ applicability for implants. This work provides a thorough examination of the surface, mechanical and wettability properties of multifunctional hydrothermally synthesised nanostructured materials, capable of killing bacteria whilst improving osteoblast metabolic rates, leading to improved osseointegration and antibacterial properties of orthopaedic implants.

Titanium-based implant comprising a porous microstructure assembled with nanoleaves and controllable silicon-ion release for enhanced osseointegration

Osseointegration is crucial for early fixation as well as for long-term implantation success, hence numerous efforts have been made to tune the surface topography or chemical composition of biomedical implants to improve osseointegration. In this work, various nanostructures, including nanoflocs, nanobundles, nanorods, and nanoleaves, were introduced to the surface of silicon (Si)-incorporated microporous structure to form Si-incorporated micro-nano hierarchical structures on titanium (Ti)-based implants. The osseointegration of the implants were systemically assessed in vivo and in vitro. The in vitro evaluations showed that the nanostructures promoted the protein adsorption, thus modulating the early cellular responses, including the attachment and spreading of osteoblasts and human endothelial cells (HUVECs), and subsequent cell proliferation and differentiation. Furthermore, compared with the single microporous structure, the nanostructures located over the microporous structure protected the Si ions from quick release and allowed the long-term sustained Si-ions release, which further contributed to the proliferation and differentiation of osteoblasts and vascular endothelial growth factor (VEGF) secretion as well as the tube formation of HUVECs. Collectively, the favorable nano-surface structures, especially the nanoleaves structure, and the constant Si-ion release together led to robust osteogenic and angiogenic activities. More importantly, in vivo micro-CT evaluation and histological observations further verified that the Si-incorporated micro-nano hierarchical implant with nanoleaves structure could efficiently promote new bone formation, thus indicating it was an attractive candidate as a next-generation bone-implant material.

Effect of a biomimetic titania mesoporous coating doped with Sr on the osteogenic activity

Fabrication of titanium (Ti)-based biomedical implants with appropriate topography as well as capacity for drug delivery is highly pursued in the field of orthopedic and dental implants. In this study, a biomimetic mesoporous coating imbedded with strontium (MPs-Sr) is prepared by the high current anodization (HCA) and hydrothermal treatment (HT). This coating provides a more stable mechanical performance than the conventional nanotube arrays. The Sr loading is regulated by the HT reaction time and the Sr is released in a controllable manner from the MPs-Sr surface. The hydrophilic performance of MPs-Sr are significantly improved. Furthermore, it is showed that the attachment and spreading of preosteoblast MC3T3-E1 cells are significantly up-regulated by the nanoscale topology of MPs and the doped Sr. The improved collagen secretion and matrix mineralization levels of cells are closely related with the Sr release. The excellent osteogenic properties of MPs-Sr samples highlight their promising potential for use in clinical application.

Deferoxamine loaded titania nanotubes substrates regulate osteogenic and angiogenic differentiation of MSCs via activation of HIF-1α signaling

To develop biomaterials for inducing osteogenic and angiogenic differentiation of mesenchymal stem cells (MSCs) is crucial for bone repair. In this study, we employed titania nanotubes (TNT) as drug nanoreservoirs to load deferoxamine (DFO), and then deposited chitosan (Chi) and gelatin (Gel) multilayer as coverage structure via layer-by-layer (LBL) assembly technique, resulting in TNT-DFO-LBL substrates. Scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contact angle measurements were employed to characterize the physical and chemical properties of the substrates. The results proved the successful fabrication of multilayer coating on TNT array. DFO released from the TNT arrays in a sustained manner. The drug-device combination titanium (Ti) substrates positively improved the adhesion, proliferation, osteogenic/angiogenic differentiation of MSCs and mediated the growth behavior of human umbilical vein endothelial cells (HUVECs). Moreover, the TNT-DFO-LBL substrates up-regulated osteogenic and angiogenic differentiation related genes expression of MSCs by activating HIF-1α signaling pathway. The approach presents here has a potential impact on the development of high quality Ti-based orthopedic implants.

Pheochromocytoma (PC12) Cell Response on Mechanobactericidal Titanium Surfaces

Titanium is a biocompatible material that is frequently used for making implantable medical devices. Nanoengineering of the surface is the common method for increasing material biocompatibility, and while the nanostructured materials are well-known to represent attractive substrata for eukaryotic cells, very little information has been documented about the interaction between mammalian cells and bactericidal nanostructured surfaces. In this study, we investigated the effect of bactericidal titanium nanostructures on PC12 cell attachment and differentiation—a cell line which has become a widely used in vitro model to study neuronal differentiation. The effects of the nanostructures on the cells were then compared to effects observed when the cells were placed in contact with non-structured titanium. It was found that bactericidal nanostructured surfaces enhanced the attachment of neuron-like cells. In addition, the PC12 cells were able to differentiate on nanostructured surfaces, while the cells on non-structured surfaces were not able to do so. These promising results demonstrate the potential application of bactericidal nanostructured surfaces in biomedical applications such as cochlear and neuronal implants.

Preparation of well-distributed titania nanopillar arrays on Ti6Al4V surface by induction heating for enhancing osteogenic differentiation of stem cells

Great effort has recently been devoted to the preparation of nanoscale surfaces on titanium-based implants to achieve clinically fast osteoinduction and osseointegration, which relies on the unique characteristics of the nanostructure. In this work, we used induction heating treatment (IHT) as a rapid oxidation method to fabricate a porous nanoscale oxide layer on the Ti6Al4V surface for better medical application. Well-distributed vertical nanopillars were yielded by IHT for 20-35 s on the alloy surface. The composition of the oxides contained rutile/anatase TiO₂ and a small amount of Al₂O₃ between the TiO₂ grain boundaries (GBs). This technology resulted in a reduction and subsequent increase of surface roughness of 26-32 nm when upregulating the heating time, followed by the successive enhancement of the thickness, wettability and adhesion strength of the oxidation layer to the matrix. The surface hardness also distinctly rose to 554 HV in the IHT-35 s group compared with the 350 HV of bare Ti6Al4V. The massive small-angle GBs in the bare alloy promoted the formation of nanosized oxide crystallites. The grain refinement and deformation texture reduction further improved the mechanical properties of the matrix after IHT. Moreover, in vitro experiments on a mesenchymal stem cell (BMSC) culture derived from human bone marrow for 1-7 days indicated that the nanoscale layers did not cause cytotoxicity, and facilitated cell differentiation in osteoblasts by enhancing the gene and osteogenesis-related protein expressions after 1-3 weeks of culturing. The increase of the IHT time slightly advanced the BMSC proliferation and differentiation, especially during long-term culture. Our findings provide strong evidence that IHT oxidation technology is a novel nanosurface modification technology, which is potentially promising for further clinical development.

Osteogenic nanostructured titanium surfaces with antibacterial properties under conditions that mimic the dynamic situation in the oral cavity

The study aim was to assess the impact of different surface nanofeatures on otherwise smooth titanium surfaces on bacterial adhesion as well as on their osteogenic potential.