Evaluation of Stress on Acupuncture with Nano-Etched and Diamond-Like Carbon (DLC) Coating Surface Modifications

The aim of the present study was to investigate the effect of nano-etched surface and diamond-like carbon (DLC) surface acupuncture needles on human pain perception, by finite element method (FEM). Skin models were reconstructed by 3D computer programs. The stress is an important role in acupuncture needle applications for clinical treatment. Many studies have investigated finite element researches for acupuncture; however, few have evaluated a model for acupuncture with and without\ modified surface. The results revealed that abnormal focusing stress was found when acupuncture with nano-etched surface. Moreover, the unbalance stress was found on the top of the skin model in the nano-etched group, the highest stress also appeared in the top region. Acupuncture with nano-etched surface would be an effective means for stimulating skin. These results indicate subtle but significant effects of acupuncture stimulation with nano-etched surface needles, compared to acupuncture with untreated needles in healthy participants.

Multi-Omics Analysis of Oral Bacterial Biofilm on Titanium Oxide Nanostructure Modified Implant Surface: in Vivo Sequencing-Based Pilot Study in Beagle Dogs

Background and aimsSurface modifications of titanium implants play essential role in facilitating osteointegration and enhancing their antimicrobial properties, while the latter is critical for preventing infectious diseases caused by the biofilm. However, it remains unknown about how the surface modifications could affect the composition and functional gene expression of oral microbiota deposited on the titanium implants. In this study, we aimed to investigate the impact of different nanostructured surfaces on the biofilm in vivo.ResultsNanophase calcium phosphate were successfully deposited into or between the TiO2 nanotubes with a diameter of 70–90 nm. NT and NTN surfaces showed increased roughness than the MP surface. XPS spectra showed that the O 1s was mainly divided into two bands in MP and NT samples, including Ti-O and -OH, while the surface modification of TiO2 nanotube in NT accounted for the increased intensity of Ti-O with the reference to that in MP samples. After the deposition of calcium phosphate, two new elemental peaks of Ca and P can be identified from the XPS survey spectrum of NTN. Moreover, the O 1s of NTN sample could be differentiated into three peaks, while the new one represented the -PO band. The 16S rDNA sequencing results showed that NT and NTN had minimal impact on the diversity and community structure of oral microbiota. Metatranscriptomic sequencing revealed that differentially expressed genes (DEGs) mostly differed in the terms of the biological process and cellular component on different surfaces. Gene Ontology (GO) terms enrichment indicated that NTN down-regulate the genes associated in localization and locomotion. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that the DEGs were associated with microbial metabolism, protein synthesis and bacterial invasion of epithelial cells.ConclusionTiO2 nanotube and calcium phosphate-coated TiO2 nanotube despite improving the antimicrobial properties of implant surfaces, had unexpectedly minimal impact on the microbiome composition and diversity. Notably, nanostructured titanium surfaces could inhibit the bacterial migration and colonization, down-regulate the pathogen invasion pathways, and further destruct bacterial cellular membrane, all in all, conferred the bactericidal properties.

Biomedical Alloys and Physical Surface Modifications: A Mini-Review

Biomedical alloys are essential parts of modern biomedical applications. However, they cannot satisfy the increasing requirements for large-scale production owing to the degradation of metals. Physical surface modification could be an effective way to enhance their biofunctionality. The main goal of this review is to emphasize the importance of the physical surface modification of biomedical alloys. In this review, we compare the properties of several common biomedical alloys, including stainless steel, Co–Cr, and Ti alloys. Then, we introduce the principle and applications of some popular physical surface modifications, such as thermal spraying, glow discharge plasma, ion implantation, ultrasonic nanocrystal surface modification, and physical vapor deposition. The importance of physical surface modifications in improving the biofunctionality of biomedical alloys is revealed. Future studies could focus on the development of novel coating materials and the integration of various approaches.

The Application of Nanomaterials in Angiogenesis

Induction of angiogenesis has enormous potential in the treatment of ischemic diseases and the promotion of bulk tissue regeneration. However, the poor activity of angiogenic cells and proangiogenic factors after transplantation is the main problem that imposes its wide applications. Recent studies have found that the development of nanomaterials has solved this problem to some extent. Nanomaterials can be mainly classified into inorganic nanomaterials represented by metals, metal oxides and metal hydroxides, and organic nanomaterials including DNA tetrahedrons, graphene, graphene oxide, and carbon nanotubes. These nanomaterials can induce the release of angiogenic factors either directly or indirectly, thereby initiating a series of signaling pathways to induce angiogenesis. Moreover, appropriate surface modifications of nanomaterial facilitate a variety of functions, such as enhancing its biocompatibility and biostability. In clinical applications, nanomaterials can promote the proliferation and differentiation of endothelial cells or mesenchymal stem cells, thereby promoting the migration of hemangioblast cells to form new blood vessels. This review outlines the role of nanomaterials in angiogenesis and is intended to provide new insights into the clinical treatment of systemic and ischemic diseases.

Analysis of the Influence of Surface Modifications on the Fatigue Behavior of Hot Work Tool Steel Components

Hot work tool steels (HWS) are widely used for high performance components as dies and molds in hot forging processes, where extreme process-related mechanical and thermal loads limit tool life. With the functionalizing and modification of tool surfaces with tailored surfaces, a promising approach is given to provide material flow control resulting in the efficient die filling of cavities while reducing the process forces. In terms of fatigue properties, the influence of surface modifications on surface integrity is insufficiently studied. Therefore, the potential of the machining processes of high-feed milling, micromilling and grinding with regard to the implications on the fatigue strength of components made of HWS (AISI H11) hardened to 50 ± 1 HRC was investigated. For this purpose, the machined surfaces were characterized in terms of surface topography and residual stress state to determine the surface integrity. In order to analyze the resulting fatigue behavior as a result of the machining processes, a rotating bending test was performed. The fracture surfaces were investigated using fractographic analysis to define the initiation area and to identify the source of failure. The investigations showed a significant influence of the machining-induced surface integrity and, in particular, the induced residual stress state on the fatigue properties of components made of HWS.