Ca-Ag coexisting nano-structured titania layer on Ti metal surface with enhanced bioactivity, antibacterial and cell compatibility

Preparation and reverse recycling logistics of a new type of nano-filled antibacterial layer packaging film for dairy products

Introduction: Dairy products are loved by people because of their high nutritional value, but they have also become the most ideal breeding places for microorganisms. Some dairy packaging has the problem of lax sealing, resulting in products susceptible to contamination and deterioration. The harmful microorganisms and bacteria contained in them will pose a serious threat to people's health. Therefore, a good antibacterial protection is very important for dairy products. The purpose of this paper is to study the preparation and reverse recycling logistics of a new type of nano-filled antibacterial layer packaging film for dairy products. Methods: A new type of nano-filled antibacterial layer packaging film is prepared by extrusion casting method, and its mechanical properties and antibacterial properties are analyzed. Results: The experimental results in this article show that the prepared new nano-filled antibacterial layer packaging film has lower light transmittance and water vapor transmission rate, and has obvious antibacterial properties against Staphylococcus aureus and Escherichia coli, and has good barrier properties. Discussion: The antibacterial rate of the bacteria in the petri dish is as high as 99.97% after being placed for 120 days, and the antibacterial performance can be enhanced by the ratio of glycerol and starch content, and the new nano-filled antibacterial film prepared is degradable Sex, can be better recycled.

Surface modification techniques of titanium and titanium alloys for biomedical orthopaedics applications: A review

Biomedical alloys have an important share in orthopedic applications. Among them, titanium and its titanium alloys are widely used as implant materials because of their excellent mechanical properties and non-cytotoxicity. However, its disadvantages such as its biological inertness and poor antibacterial properties inhibit its further development. Therefore, the surface properties of titanium are crucial in the implantation process and determine the success of the implant. The main purpose of this review is to provide a comprehensive and detailed description of the modification techniques used for the surface modification of titanium implants. In this paper, the corresponding technical methods are introduced systematically from four aspects: mechanical method, physical surface modification, chemical surface modification and electrochemical technique to understand the experimental mechanism of each modification technique, and the above methods can indeed improve the various properties of titanium and its alloys. With the increasing demand for implants in the future, the requirements for surface properties will also increase. Therefore, the development of new coating materials with higher performance by combining various advantages of existing modification technologies is the main trend of future research on surface modification of titanium alloys.

Bioactive and antimicrobial macro-/micro-nanoporous selective laser melted Ti-6Al-4V alloy for biomedical applications

Metal Additive Manufacturing (AM) technology is an emerging technology in biomedical field due to its unique ability to manufacture customized implants [Patients-specific Implants (PSIs)] replicating the complex bone structure from the relevant metal powders. PSIs could be developed through any AM technology, but the ultimate challenge lies in integrating the metallic implant with the living bone. Considering this aspect, in the present study, Ti alloy (Ti–6Al–4V) powder has been used to fabricate scaffolds of channel type macropores with 0–60% porosity using selective laser melting (SLM) and subsequent post-treatments paving way for surface microporosities. Surface chemical and subsequent heat treatments were carried out on thus developed Ti alloy scaffolds to improve its bioactivity, antibacterial activity and osteoblastic cell compatibility. NaOH and subsequent Ca(NO₃)₂/AgNO₃ treatment induced the formation of a nanoporous network structure decorated with Ca–Ag ions. Ag nanoparticles covering the entire scaffold provided antibacterial activity and the presence of Ca²⁺ ions with anatase TiO₂ layer further improved the bioactivity and osteoblastic cell compatibility of the scaffold. Therefore, SLM technology combined with heat treatment and surface modification could be effectively utilized to create macro-micro-nano structure scaffolds of Ti alloy that are bioactive, antibacterial, and cytocompatible.

Construction of multi-layered Zn-modified TiO2 coating by ultrasound-auxiliary micro-arc oxidation: Microstructure and biological property

Surfaces with desirable cytocompatibility and bactericidal ability are favoured for orthopaedic implants to stimulate osteogenic activity and to prevent implant-associated infection. In this work, we creatively introduce ultrasonic vibration (UV) to micro-arc oxidation (MAO) process and explore its influence on the microstructure, corrosion property and biological responses of Zn-modified TiO₂ coating. With the introduction of UV, a uniform surface layer with homogeneously-distributed clusters could be produced as the outer layer, which possesses a fusion band with the underlying TiO₂. The microstructural modification associated with UV results in the enhanced corrosion resistance, increased adhesive strength and improved biological performances of the resultant coating relative to that with the absence of UV. Hence, the ultrasonic auxiliary micro-arc oxidation (UMAO) is regarded as a promising surface modification method to produce Ti-based orthopaedic implants of high quality.

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.