A homogeneous dopamine-silver nanocomposite coating: striking a balance between the antibacterial ability and cytocompatibility of dental implants

Potential role of metal nanoparticles in treatment of peri-implant mucositis and peri-implantitis

Peri-implantitis (PI), a pathological condition associated with plaque, affects the tissues around dental implants. In addition, peri-implant mucositis (PIM) is a precursor to the destructive inflammatory PI and is an inflammation of the soft tissues surrounding the dental implant. It is challenging to eradicate and regulate the PI treatment due to its limited effectiveness. Currently, there is a significant interest in the development and research of additional biocompatible materials to prevent the failure of dental implants. Nanotechnology has the potential to address or develop solutions to the significant challenge of implant failure caused by cytotoxicity and biocompatibility in dentistry. Nanoparticles (NPs) may be used as carriers for the release of medicines, as well as to make implant coatings and supply appropriate materials for implant construction. Furthermore, the bioactivity and therapeutic efficacy of metal NPs in peri-implant diseases (PID) are substantiated by a plethora of in vitro and in vivo studies. Furthermore, the use of silver (Ag), gold (Au), zinc oxide, titanium oxide (TiO2), copper (Cu), and iron oxide NPs as a cure for dental implant infections brought on by bacteria that have become resistant to several medications is the subject of recent dentistry research. Because of their unique shape-dependent features, which enhance bio-physio-chemical functionalization, antibacterial activity, and biocompatibility, metal NPs are employed in dental implants. This study attempted to provide an overview of the application of metal and metal oxide NPs to control and increase the success rate of implants while focusing on the antimicrobial properties of these NPs in the treatment of PID, including PIM and PI. Additionally, the study reviewed the potential benefits and drawbacks of using metal NPs in clinical settings for managing PID, with the goal of advancing future treatment strategies for these conditions.

Polydopamine-Based Biomaterials in Orthopedic Therapeutics: Properties, Applications, and Future Perspectives

Polydopamine is a versatile and modifiable polymer, known for its excellent biocompatibility and adhesiveness. It can also be engineered into a variety of nanoparticles and biomaterials for drug delivery, functional modification, making it an excellent choice to enhance the prevention and treatment of orthopedic diseases. Currently, the application of polydopamine biomaterials in orthopedic disease prevention and treatment is in its early stages, despite some initial achievements. This article aims to review these applications to encourage further development of polydopamine for orthopedic therapeutic needs. We detail the properties of polydopamine and its biomaterial types, highlighting its superior performance in functional modification on nanoparticles and materials. Additionally, we also explore the challenges and future prospects in developing optimal polydopamine biomaterials for clinical use in orthopedic disease prevention and treatment.

Yolk-shelled silver nanowire@amorphous metal-organic framework for controlled drug delivery and light-promoting infected wound healing

Bacteria-infected wounds healing has been greatly hindered by antibiotic resistance and persistent inflammation. It is crucial to develop multifunctional nanocomposites that possess effective antibacterial properties and can simultaneously accelerate the wound healing process to overcome the above challenges. Herein, we prepared a yolk-shell structured Ag nanowires (NWs)@amorphous hollow ZIF-67 by etching ZIF-67 onto the Ag NWs for infected wound healing for the first time. The etched hollow structure of amorphous ZIF-67 in the nanocomposite makes it a promising platform for loading healing-promoting drugs. We extensively studied the antibacterial and healing-promoting properties of the curcumin (CCM)-loaded nanocomposite (Ag NWs@C-HZ67). Ag NWs, being noble metal materials with plasmonic effects, can absorb a broad range of natural light and convert it to thermal energy. This photothermal conversion further improves the release of antibacterial components and wound healing drugs when exposed to light. During the healing process of an infected wound, Ag and Co ions were released from Ag NWs@C-HZ67 upon direct contact with the wound exudate and under the influence of light irradiation. Simultaneously, the loaded CCM leaked out to repair the infected wound. The minimum inhibitory concentrations of the Ag NWs@C-HZ67 groups against Escherichia coli and Staphylococcus aureus bacteria decreased to 3 and 3 μg ml-1 when exposed to white light. Furthermore, an in vivo assessment of infected wound healing demonstrated that combining Ag NWs@C-HZ67 with light significantly accelerated the wound healing process, achieving 70% healing by the 6th day and almost complete healing by the 8th day. This advanced nanocomposite, consisting of components that possess antibacterial and growth-promoting properties, offers a safe, effective and clinically-translatable solution for accelerating the healing process of infected wounds.

Influencing factors and evaluation methods for early stability of immediate implant

At present, implant restoration has become a hot research topic in the field of prosthodontics. The in-depth studies of new materials and new technologies enable immediate implantation, immediate and early loading to be realized, which meets the needs of patients for shortening the course of implant restoration and obtaining better aesthetic effects. However, compared with the traditional delayed implantation technology, it is equally challenging for clinicians how to achieve and even improve the initial and long-term stability of implants in order to raise the success rate of implant restoration. The initial stability of the implant is influenced by a combination of factors, including the implant, the patient's condition, and the surgical procedure. Recently, there have been a lot of studies on the influencing factors and common research methods for immediate implant stability and bone healing. Summarizing and analyzing them can provide reference for preoperative evaluation, surgical plan and loading timing of immediate implant restoration in the later stage.

Fibrous topology promoted pBMP2-activated matrix on titanium implants boost osseointegration

Titanium (Ti) implants have been extensively used after surgical operations. Its surface bioactivity is of importance to facilitate integration with surrounding bone tissue, and ultimately ensure stability and long-term functionality of the implant. The plasmid DNA-activated matrix (DAM) coating on the surface could benefit osseointegration but is still trapped by poor transfection for further application, especially on the bone marrow mesenchymal stem cells (BMSCs) in vivo practical conditions. Herein, we constructed a DAM on the surface of fibrous-grained titanium (FG Ti) composed of phase-transition lysozyme (P) as adhesive, cationic arginine-rich lipid (RLS) as the transfection agent and plasmid DNA (pDNA) for bone morphology protein 2 (BMP2) expression. The cationic lipid RLS improved up to 30-fold higher transfection than that of commercial reagents (Lipofectamine 2000 and polyethyleneimine) on MSC. And importantly, Ti surface topology not only promotes the DAM to achieve high transfection efficiency (∼75.7% positive cells) on MSC due to the favorable combination but also reserves its contact induction effect for osteoblasts. Upon further exploration, the fibrous topology on FG Ti could boost pDNA uptake for gene transfection, and cell migration in MSC through cytoskeleton remodeling and induce contact guidance for enhanced osteointegration. At the same time, the cationic RLS together with adhesive P were both antibacterial, showing up to 90% inhibition rate against Escherichia coli and Staphylococcus aureus with reduced adherent microorganisms and disrupted bacteria. Finally, the FG Ti-P/pBMP2 implant achieved accelerated bone healing capacities through highly efficient gene delivery, aligned surface topological structure and increased antimicrobial properties in a rat femoral condylar defect model.

The shape-dependent inhibitory effect of rhein/silver nanocomposites on porcine reproductive and respiratory syndrome virus

Traditional Chinese medicines (TCMs)/nanopreparations as viral antagonists exhibited a structure-function correlation, i.e., the differences in surface area/volume ratio caused by the variations in shape and size could result in different biochemical properties and biological activities, suggesting an important impact of morphology and structure on the antiviral activity of TCM-based nanoparticles. However, few studies paid attention to this aspect. Here, the effect of TCM-based nanoparticles with different morphologies on their antiviral activity was explored by synthesizing rhein/silver nanocomposites (Rhe@AgNPs) with spherical (S-Rhe/Ag) and linear (L-Rhe/Ag) morphologies, using rhein (an active TCM ingredient) as a reducing agent and taking its self-assembly advantage. Using porcine reproductive and respiratory syndrome virus (PRRSV) as a model virus, the inhibitory effects of S-Rhe/Ag and L-Rhe/Ag on PRRSV were compared. Results showed that the product morphology could be regulated by varying pH values, and both S- and L-Rhe/Ag exhibited good dispersion and stability, but with a smaller size for L-Rhe/Ag. Antiviral experiments revealed that Rhe@AgNPs could effectively inhibit PRRSV infection, but the antiviral effect was morphology-dependent. Compared with L-Rhe/Ag, S-Rhe/Ag could more effectively inactivate PRRSV in vitro and antagonize its adsorption, invasion, replication, and release stages. Mechanistic studies indicated that Rhe@AgNPs could reduce the production of reactive oxygen species (ROS) induced by PRRSV infection, and S-Rhe/Ag also had stronger ROS inhibitory effect. This work confirmed the inhibitory effect of Rhe@AgNPs with different morphologies on PRRSV and provided useful information for treating PRRSV infection with metal nanoparticles synthesized from TCM ingredients.