Profiling to Probing: Atomic force microscopy to characterize nano-engineered implants

Investigating Simulated Cellular Interactions on Nanostructured Surfaces with Antibacterial Properties: Insights from Force Curve Simulations

This study investigates the simulation of interactions between cells and antibacterial nanostructured surfaces. Understanding the physical interaction forces between cells and nanostructured surfaces is crucial for developing antibacterial materials, yet existing physical models are limited. Force simulation studies can simplify analysis by focusing on mechanical interactions while disregarding factors such as bacterial deformation and complex biochemical signals. To simulate these interactions, Atomic Force Microscopy (AFM) was employed to generate force curves, allowing precise monitoring of the interaction between a 5 µm spherical cantilever tip and titanium alloy (Ti6Al4V) surfaces. AFM uniquely enables customized approaches and retraction cycles, providing detailed insights into attractive-repulsive forces across different surface morphologies. Two nanostructured surfaces, created via hydrothermal etching using KOH and NaOH, were compared to a Ti6Al4V control surface. Results demonstrated significant changes in nanomechanical properties due to surface chemistry and morphology. The Ti6Al4V control surface exhibited a 44 ± 5 N/m stiffness, which decreased to 20 ± 3 N/m on KOH-etched nanostructured (NS) surfaces and 29 ± 4 N/m on NaOH-etched NS surfaces. Additionally, surface energy decreased by magnitude on nanostructured surfaces compared to the control. The nature of interaction forces also varied: short-range forces were predominant on KOH-etched surfaces, while NaOH-etched surfaces exhibited stronger long-range forces. These findings provide valuable insights into how nanostructure patterning influences cell-like interactions, offering potential applications in antibacterial surface design. By tailoring nanomechanical properties through specific etching techniques, biomaterial performance can be optimized for clinical applications, enhancing antibacterial efficacy and reducing microbial adhesion.

Guidance on biomaterials for periodontal tissue regeneration: Fabrication methods, materials and biological considerations

Regeneration of the multiple tissues and interfaces in the periodontal complex necessitates multidisciplinary evaluation to establish structure/function relationships. This article, an initiative of the Academy of Dental Materials, provides guidance for performing chemical, structural, and mechanical characterization of materials for periodontal tissue regeneration, and outlines important recommendations on methods of testing bioactivity, biocompatibility, and antimicrobial properties of biomaterials/scaffolds for periodontal tissue engineering. First, we briefly summarize periodontal tissue engineering fabrication methods. We then highlight critical variables to consider when evaluating a material for periodontal tissue regeneration, and the fundamental tests used to investigate them. The recommended tests and designs incorporate relevant international standards and provide a framework for characterizing newly developed materials focusing on the applicability of those tests for periodontal tissue regeneration. The most common methods of biofabrication (electrospinning, injectable hydrogels, fused deposition modelling, melt electrowriting, and bioprinting) and their specific applications in periodontal tissue engineering are reviewed. The critical techniques for morphological, chemical, and mechanical characterization of different classes of materials used in periodontal regeneration are then described. The major advantages and drawbacks of each assay, sample sizes, and guidelines on specimen preparation are also highlighted. From a biological standpoint, fundamental methods for testing bioactivity, the biocompatibility of materials, and the experimental models for testing the antimicrobial potential are included in this guidance. In conclusion, researchers performing studies on periodontal tissue regeneration will have this guidance as a tool to assess essential properties and characteristics of their materials/scaffold-based strategies.

Transformative insights in breast cancer: review of atomic force microscopy applications

Breast cancer remains one of the foremost global health concerns, highlighting the urgent need for innovative diagnostic and therapeutic strategies. Traditional imaging techniques, such as mammography and ultrasound, play essential roles in clinical practice; however, they often fall short in detecting early-stage tumors and providing comprehensive insights into the mechanical properties of cancer cells. In this context, Atomic Force Microscopy (AFM) has emerged as a transformative tool in breast cancer research, owing to its high-resolution imaging capabilities and nanomechanical characterization. This review explores recent advancements in AFM technology as applied to breast cancer research, emphasizing key findings that include the differentiation of various stages of tumor progression through high-resolution imaging, precise characterization of mechanical properties, and the capability for single-cell analysis. These capabilities not only enhance our understanding of tumor heterogeneity but also reveal potential biomarkers for early detection and therapeutic targets. Furthermore, the review critically examines several challenges and limitations associated with the application of AFM in breast cancer research. Issues such as complexities in sample preparation, accessibility, and the cost of AFM technology are discussed. Despite these challenges, the potential of AFM to transform our understanding of breast cancer biology is significant. Looking ahead, continued advancements in AFM technology promise to deepen our insights into breast cancer biology and guide innovative therapeutic strategies aimed at improving patient outcomes.

The application of nanomaterials in tumor therapy based on the regulation of mechanical properties

Mechanical properties, as crucial physical properties, have a significant impact on the occurrence, development, and metastasis of tumors. Regulating the mechanical properties of tumors to enhance their sensitivity to radiotherapy and chemotherapy has become an important strategy in the field of cancer treatment. Over the past few decades, nanomaterials have made remarkable progress in cancer therapy, either based on their intrinsic properties or as drug delivery carriers. However, the investigation of nanomaterials of mechanical regulation in tumor therapy is currently in its initial stages. The mechanical properties of nanomaterials themselves, drug carrier targeting, and regulation of the mechanical environment of tumor tissue have far-reaching effects on the efficient uptake of drugs and clinical tumor treatment. Therefore, this review aims to comprehensively summarize the applications and research progress of nanomaterials in tumor therapy based on the regulation of mechanical properties, in order to provide strong support for further research and the development of treatment strategies in this field.

Antifouling nanoplatform for controlled attachment ofE. coli

Biofouling is the most common cause of bacterial contamination in implanted materials/devices resulting in severe inflammation, implant mobilization, and eventual failure. Since bacterial attachment represents the initial step toward biofouling, developing synthetic surfaces that prevent bacterial adhesion is of keen interest in biomaterials research. In this study, we develop antifouling nanoplatforms that effectively impede bacterial adhesion and the consequent biofilm formation. We synthesize the antifouling nanoplatform by introducing silicon (Si)/silica nanoassemblies to the surface through ultrafast ionization of Si substrates. We assess the effectiveness of these nanoplatforms in inhibitingEscherichia coli(E. coli) adhesion. The findings reveal a significant reduction in bacterial attachment on the nanoplatform compared to untreated silicon, with bacteria forming smaller colonies. By manipulating physicochemical characteristics such as nanoassembly size/concentration and nanovoid size, we further control bacterial attachment. These findings suggest the potential of our synthesized nanoplatform in developing biomedical implants/devices with improved antifouling properties.

Evaluation of High-Performance Polyether Ether Ketone Polymer Treated with Piranha Solution and Epigallocatechin-3-Gallate Coating

Background

Dental implantation has become a standard procedure with high success rates, relying on achieving osseointegration between the implant surface and surrounding bone tissue. Polyether ether ketone (PEEK) is a promising alternative to traditional dental implant materials like titanium, but its osseointegration capabilities are limited due to its hydrophobic nature and reduced surface roughness.

Objective

The aim of the study is to increase the surface roughness and hydrophilicity of PEEK by treating the surface with piranha solution and then coating the surface with epigallocatechin-3-gallate (EGCG) by electrospraying technique.

Materials and Methods

The study includes four groups intended to investigate the effect of piranha treatment and EGCG coating: a control group of PEEK discs with no treatment (C), PEEK samples treated with piranha solution (P), a group of PEEK samples coated with EGCG (E), and a group of PEEK samples treated with piranha solution and coated with EGCG (PE). Surface roughness, wettability, and microhardness were assessed through statistical analysis.

Results

Piranha treatment increased surface roughness, while EGCG coating moderated it, resulting in an intermediate roughness in the PE group. EGCG significantly improved wettability, as indicated by the reduced contact angle. Microhardness increased by about 20% in EGCG-coated groups compared to noncoated groups. Statistical analysis confirmed significant differences between groups in all tests.

Conclusion

This study demonstrates the potential of EGCG coating to enhance the surface properties of PEEK as dental implants. The combined piranha and EGCG modification approach shows promise for improved osseointegration, although further vivo research is necessary. Surface modification techniques hold the key to optimizing biomaterial performance, bridging the gap between laboratory findings and clinical implementation in dental implantology.

Bridging Smart Nanosystems with Clinically Relevant Models and Advanced Imaging for Precision Drug Delivery

Intracellular delivery of nano-drug-carriers (NDC) to specific cells, diseased regions, or solid tumors has entered the era of precision medicine that requires systematic knowledge of nano-biological interactions from multidisciplinary perspectives. To this end, this review first provides an overview of membrane-disruption methods such as electroporation, sonoporation, photoporation, microfluidic delivery, and microinjection with the merits of high-throughput and enhanced efficiency for in vitro NDC delivery. The impact of NDC characteristics including particle size, shape, charge, hydrophobicity, and elasticity on cellular uptake are elaborated and several types of NDC systems aiming for hierarchical targeting and delivery in vivo are reviewed. Emerging in vitro or ex vivo human/animal-derived pathophysiological models are further explored and highly recommended for use in NDC studies since they might mimic in vivo delivery features and fill the translational gaps from animals to humans. The exploration of modern microscopy techniques for precise nanoparticle (NP) tracking at the cellular, organ, and organismal levels informs the tailored development of NDCs for in vivo application and clinical translation. Overall, the review integrates the latest insights into smart nanosystem engineering, physiological models, imaging-based validation tools, all directed towards enhancing the precise and efficient intracellular delivery of NDCs.

Damage Behavior with Atomic Force Microscopy on Anti-Bacterial Nanostructure Arrays

The atomic force microscope is a versatile tool for assessing the topography, friction, and roughness of a broad spectrum of surfaces, encompassing anti-bacterial nanostructure arrays. Measuring and comparing all these values with one instrument allows clear comparisons of many nanomechanical reactions and anomalies. Increasing nano-Newton-level forces through the cantilever tip allows for the testing and measuring of failure points, damage behavior, and functionality under unfavorable conditions. Subjecting a grade 5 titanium alloy to hydrothermally etched nanostructures while applying elevated cantilever tip forces resulted in the observation of irreversible damage through atomic force microscopy. Despite the damage, a rough and non-uniform morphology remained that may still allow it to perform in its intended application as an anti-bacterial implant surface. Utilizing an atomic force microscope enables the evaluation of these surfaces before their biomedical application.