Formation of OTS self-assembled monolayers at chemically treated titanium surfaces

Hydrogel-Anchored Fe-Based Amorphous Coatings with Integrated Antifouling and Anticorrosion Functionality

Biofouling and corrosion of underwater equipment induced by marine organisms have become major issues in the marine industry. The superior corrosion resistance of Fe-based amorphous coatings makes them suitable for marine applications; however, they have a poor antifouling ability. In this work, a hydrogel-anchored amorphous (HAM) coating with satisfactory antifouling and anticorrosion performance is designed, utilizing an interfacial engineering strategy involving micropatterning, surface hydroxylation, and a dopamine intermediate layer to increase the adhesion strength between the hydrogel layer and the amorphous coating. The as-obtained HAM coating exhibits exceptional antifouling properties, achieving 99.8% resistance to algae, 100% resistance to mussels, and excellent biocorrosion resistance against Pseudomonas aeruginosa. Antifouling and anticorrosion performance of the HAM coating was also explored by conducting a marine field test in the East China Sea, and no signs of corrosion and fouling are observed after 1 month of immersion. It is revealed that the outstanding antifouling properties stem from the killing-resisting-camouflaging trinity that resists organism attachment across different length scales, and the excellent anticorrosion performance originates from the remarkable barrier of the amorphous coating against Cl^- ion diffusion and microbe-induced biocorrosion. This work presents a novel methodology for designing marine protective coating with excellent antifouling and anticorrosion properties.

Biomimetic Hydroxyapatite Composite Coatings with a Variable Morphology Mediated by Silk Fibroin and Its Derived Peptides Enhance the Bioactivity on Titanium

Various modifications performed on titanium alloy surfaces are shown to improve osteointegration and promote the long-term success of implants. In this work, a bioactive nanostructured hydroxyapatite (HA) composite coating with a variable morphology mediated by silk fibroin (SF) and its derived peptides (Cs) was prepared. Numerous experimental techniques were used to characterize the constructed coatings in terms of morphology, roughness, hydrophilicity, protein adsorption, in vitro biomineralization, and adhesion strength. The mixed protein layer with different contents of SF and Cs exhibited different secondary structures at different temperatures, effectively mediating the electrodeposited HA layer with different characteristics and finally forming proteins/HA composite coatings with versatile morphologies. The addition of Cs significantly improved the hydrophilicity and protein adsorption capacity of the composite coatings, while the electrodeposition of the HA layer effectively enhanced the adhesion between the composite coatings and Ti surface. In the in vitro mineralization experiments, all the composite coatings exhibited excellent apatite formation ability. Moreover, the composite coatings showed excellent cell growth and proliferation activity. Osteogenic induction experiments revealed that the coating could significantly increase the expression of specific osteogenic markers, including ALP, Col-I, Runx-2, and OCN. Overall, the proposed modification of the Ti implant surface by protein/HA coatings had good potential for clinical applications in enhancing bone induction and osteogenic activity of implants.

Effectiveness of Biofunctionalization of Titanium Surfaces with Phosphonic Acid

Surface functionalization of dental implant surfaces has been a developing field in biomaterial research. This study aimed to obtain self-assembled monolayers (SAMs) using carboxyethylphosphonic acid on the surface of titanium (Ti) screws, and assessed the surface characteristics, biomechanical, and cellular behavior on the obtained specimens. This study had three groups, i.e., a control (untreated screws), a test group treated with phosphonic acid, and a third group with treated acid and bone morphogenetic protein (BMP-2) for in vitro analysis of cell lines. The assessed parameters included surface wettability, surface characteristics using scanning electron microscopy (SEM), protein immobilization, and cellular behavior of fibroblasts and mesenchymal stem cells of adipose tissue (MSCat cells). For surface wettability, a Welch test was performed to compare the contact angles between control (67 ± 1.83) and test (18.84 ± 0.72) groups, and a difference was observed in the mean measurements, but was not statistically significant. The SEM analysis showed significant surface roughness on the test screws and the cellular behavior of fibroblasts, and MSCat cells were significantly improved in this group, with fibroblasts having a polygonal shape with numerous vesicles and MSCat cells stable and uniformly coating the test Ti surface. Surface biofunctionalization of Ti surfaces with phosphonic acid showed promising results in this study, but remains to be clinically validated for its applications.

Polydopamine-assisted immobilization of silk fibroin and its derived peptide on chemically oxidized titanium to enhance biological activity in vitro

Biochemical modification can endow the surface of implants with superior biological activity. Herein, silk fibroin (SF) protein and its anionic derivative peptides (Cs) were covalently immobilized onto a titanium implant surface via a polydopamine layer. The successful conjugation of SF and Cs was revealed by X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and contact angle measurements. The addition of Cs prevented the conformational transition of silk fibroin to silk II. The deposition of apatite on its surface was significantly accelerated, and the bioactive composite coating was observed to enhance protein adsorption and cell proliferation. More importantly, it also promoted the osteogenic differentiation of bone marrow stem cells (BMSCs) for the quantitative and qualitative detection of alkaline phosphatase (ALP) and alizarin red (ARS). Overall, the stable performance and enhanced osteogenic property of the composite coating promote an extensive application for clinical titanium-based implants.

Binary Silanization and Silver Nanoparticle Encapsulation to Create Superhydrophobic Cotton Fabrics with Antimicrobial Capability

Cotton fabrics are functionalized with a binary solution of fluorine-free organosilanes and "encapsulated" with silver nanoparticles to achieve both superhydrophobic and antimicrobial properties. Derived from cellulose, cotton is one of the most abundant biologically generated materials and has been used in a wide variety of consumer goods. Nonetheless, cotton fabrics are not waterproof and prone to microbial contamination. Herein we report the rapid functionalization of cotton fabrics with a binary hexane solution of methyltrichlorosilane (MTS) and octadecyltrichlorosilane (OTS) at low concentration (0.17% v/v) followed by coating with colloidal silver nanoparticles (AgNP). The combined effects of binary silanization and AgNP encapsulation produced a surface that has remarkable water contact angle of 153 ± 2° and antimicrobial properties (against gram-negative Escherichia coli). The superior performance of the modified cotton fabrics produced with fluorine-free organosilanes and silver nanoparticles augments the potential of improving the functionality of abundant biopolymers to be waterproof and contamination-resistant.

New posterior column reconstruction using titanium lamina mesh after total en bloc spondylectomy of spinal tumour

PURPOSE

To investigate the usefulness of titanium lamina mesh for posterior column reconstruction after total en bloc spondylectomy in patients with spinal tumour and evaluate the radiographic outcomes of this method.

METHOD

Eight patients who underwent total en bloc spondylectomy with posterior column reconstruction using titanium lamina mesh and bone graft to treat a spinal tumour were included in this study. The mean age at the time of surgery was 50.6 years (range, 16.5-70.9 years) and the mean follow-up duration was 50.2 months (range, 28.1-68.7 months). The pathological lesions were located from the T2 to L1 vertebrae. There were four patients in each primary and metastatic tumour group. For the posterior column reconstruction, titanium lamina mesh was used and bone graft was applied over the lamina mesh. Radiographic evaluation was used to investigate the displacement of lamina mesh and union of the grafted bone above lamina mesh.

RESULTS

At the postoperative six month follow-up, a bony bridge on the titanium mesh between upper and lower adjacent lamina was observed in all cases, except for one with infection. On the last follow-up, there was no collapse or displacement of titanium lamina mesh, and there was no instability or malalignment of the spinal column.

CONCLUSIONS

Posterior column reconstruction using titanium lamina mesh during total en bloc spondylectomy for spinal tumour was a useful surgical option that provided new lamina reconstruction for stability of spinal column and protection of the neural elements.

Calcium phosphate growth at electropolished titanium surfaces

This work investigated the ability of electropolished Ti surface to induce Hydroxyapatite (HA) nucleation and growth in vitro via a biomimetic method in Simulated Body Fluid (SBF). The HA induction ability of Ti surface upon electropolishing was compared to that of Ti substrates modified with common chemical methods including alkali, acidic and hydrogen peroxide treatments. Our results revealed the excellent ability of electropolished Ti surfaces in inducing the formation of bone-like HA at the Ti/SBF interface. The chemical composition, crystallinity and thickness of the HA coating obtained on the electropolished Ti surface was found to be comparable to that achieved on the surface of alkali treated Ti substrate, one of the most effective and popular chemical treatments. The surface characteristics of electropolished Ti contributing to HA growth were discussed thoroughly.