Extracellular vesicle production by oral bacteria related to dental caries and periodontal disease: role in microbe-host and interspecies interactions.

Extracellular vesicles (EVs) are cell membrane-derived structures between 20-400 nm in size. In bacteria, EVs play a crucial role in molecule secretion, cell wall biogenesis, cell-cell communication, biofilm development, and host-pathogen interactions. Despite these increasing reports of bacterial-derived vesicles, there remains a limited number of studies that summarize oral bacterial EVs, their cargo, and their main biological functions.

Microfabrication-based engineering of biomimetic dentin-like constructs to simulate dental aging.

Human dentin is a highly organized dental tissue displaying a complex microarchitecture consisting of micrometer-sized tubules encased in a mineralized type-I collagen matrix. As such, it serves as an important substrate for the adhesion of microbial colonizers and oral biofilm formation in the context of dental caries disease, including root caries in the elderly. Despite this issue, there remains a current lack of effective biomimetic dentin models that facilitate the study of oral microbial adhesion by considering the surface architecture at the micro- and nanoscales.

Atomic force microscopy-mediated mechanobiological profiling of complex human tissues.

Tissue mechanobiology is an emerging field with the overarching goal of understanding the interplay between biophysical and biochemical responses affecting development, physiology, and disease. Changes in mechanical properties including stiffness and viscosity have been shown to describe how cells and tissues respond to mechanical cues and modify critical biological functions. To quantitatively characterize the mechanical properties of tissues at physiologically relevant conditions, atomic force microscopy (AFM) has emerged as a highly versatile biomechanical technology.

Aloe vera peel-derived nanovesicles display anti-inflammatory properties and prevent myofibroblast differentiation.

Background: Aloe vera (AV) is a medicinal plant, most known for its beneficial effects on a variety of skin conditions. Its known active compounds include carbohydrates and flavonoids such as quercetin and kaempferol, among others. In the past decade, plant nanovesicles (NVs) have gained considerable interest as interkingdom communicators, presenting an opportunity for clinical standardization of natural products.

Quantitative nanohistology of aging dermal collagen.

The skin is the largest organ in the body and is essential for protecting us from environmental stressors such as UV radiation, pollution, and pathogens. As we age, our skin undergoes complex changes that can affect its function, appearance, and health. These changes result from intrinsic (chronological) and extrinsic (environmental) factors that can cause damage to the skin's cells and extracellular matrix.

Royal jelly extracellular vesicles promote wound healing by modulating underlying cellular responses.

royal jelly (RJ) is a well-known remedy in traditional medicine around the world and its versatile effects range from antibacterial to anti-inflammatory properties and pro-regenerative properties. As a glandular product, RJ has been shown to contain a substantial number of extracellular vesicles (EVs), and, in this study, we aimed to investigate the extent of involvement of RJEVs in wound healing-associated effects. Molecular analysis of RJEVs verified the presence of exosomal markers such as CD63 and syntenin, and cargo molecules MRJP1, defensin-1, and jellein-3.

Modulation of the biophysical and biochemical properties of collagen by glycation for tissue engineering applications.

The structural and functional properties of collagen are modulated by the presence of intramolecular and intermolecular crosslinks. Advanced Glycation End-products (AGEs) can produce intermolecular crosslinks by bonding the free amino groups of neighbouring proteins. In this research, the following hypothesis is explored: The accumulation of AGEs in collagen decreases its proteolytic degradation rates while increasing its stiffness.

Ultrastructural characterisation of young and aged dental enamel by atomic force microscopy.

Recent advances in atomic force microscopy (AFM) have allowed the characterisation of dental-associated biomaterials and biological surfaces with high resolution. In this context, the topography of dental enamel - the hardest mineralised tissue in the body - has been explored with AFM-based approaches at the microscale. With age, teeth are known to suffer changes that can impact their structural stability and function; however, changes in enamel structure because of ageing have not yet been explored with nanoscale resolution.

Antibacterial Effect of Honey-Derived Exosomes Containing Antimicrobial Peptides Against Oral Streptococci.

Purpose: Recently, our group found exosome-like extracellular vesicles (EVs) in honey displaying strong antibacterial effects; however, the underlying mechanism is still not understood. Thus, the aim of this investigation was to characterize the molecular and nanomechanical properties of honey-derived EVs in order to elucidate the mechanisms behind their antibacterial effect, as well as to determine differential antibiofilm properties against relevant oral streptococci.

Methods: honey-derived EVs (HEc-EVs) isolated via ultracentrifugation were characterized with Western Blot and ELISA to determine the presence of specific exosomal markers and antibacterial cargo, and atomic force microscopy (AFM) was utilized to explore their ultrastructural and nanomechanical properties via non-destructive immobilization onto poly-L-lysine substrates.

Bacterial adhesion to collagens: implications for biofilm formation and disease progression in the oral cavity.

Collagen is the most abundant structural protein in the body and the main component of the extracellular matrix of most tissues, including dentine and periodontal tissues. Despite the well-characterized role of collagen and specifically type-I collagen, as a ligand for host cells, its role as a substrate for bacterial adhesion and biofilm formation is less explored. Therefore, the purpose of this review is to discuss recent findings regarding the adhesion of oral bacteria to collagen surfaces and its role in the progression and severity of oral and systemic diseases.

Complex Interaction between Resident Microbiota and Misfolded Proteins: Role in Neuroinflammation and Neurodegeneration.

Neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD) and Creutzfeldt-Jakob disease (CJD) are brain conditions affecting millions of people worldwide. These diseases are associated with the presence of amyloid-β (Aβ), alpha synuclein (α-Syn) and prion protein (PrP) depositions in the brain, respectively, which lead to synaptic disconnection and subsequent progressive neuronal death. Although considerable progress has been made in elucidating the pathogenesis of these diseases, the specific mechanisms of their origins remain largely unknown.

Type I collagen hydrogels as a delivery matrix for royal jelly derived extracellular vesicles.

Throughout the last decade, extracellular vesicles (EVs) have become increasingly popular in several areas of regenerative medicine. Recently, royal jelly EVs (RJ EVs) were shown to display favorable wound healing properties such as stimulation of mesenchymal stem cell migration and inhibition of staphylococcal biofilms. However, the sustained and effective local delivery of EVs in non-systemic approaches - such as patches for chronic cutaneous wounds - remains an important challenge for the development of novel EV-based wound healing therapies.

Relationship between the Nano-Biomechanical Properties of Streptococcal Polysaccharide Capsules and Virulence Phenotype.

In common with many bacterial pathogens, has a polysaccharide capsule which facilitates immune evasion and determines virulence. Recent data have shown that the closely related also expresses polysaccharide capsules including those with an identical chemical structure to capsular serotypes. We utilized atomic force microscopy (AFM) techniques to investigate the biophysical properties of and strains expressing the same capsular serotypes that might relate to differences in virulence potential.

Phenotypic Properties of Collagen in Dentinogenesis Imperfecta Associated with Osteogenesis Imperfecta.

Introduction: Dentinogenesis imperfecta type 1 (OIDI) is considered a relatively rare genetic disorder (1:5000 to 1:45,000) associated with osteogenesis imperfecta. OIDI impacts the formation of collagen fibrils in dentin, leading to morphological and structural changes that affect the strength and appearance of teeth. However, there is still a lack of understanding regarding the nanoscale characterization of the disease, in terms of collagen ultrastructure and mechanical properties.

Potential Novel Strategies for the Treatment of Dental Pulp-Derived Pain: Pharmacological Approaches and Beyond.

The diagnosis and management of pain is an everyday occurrence in dentistry, and its effective control is essential to ensure the wellbeing of patients. Most tooth-associated pain originates from the dental pulp, a highly vascularized and innervated tissue, which is encased within mineralized dentin. It plays a crucial role in the sensing of stimuli from the local environment, such as infections (i.

Exosome-like vesicles in bee pollen, honey and royal jelly contribute to their antibacterial and pro-regenerative activity.

Microvesicles are key players in cellular communication. As glandular secretions present a rich source of active exosomes, we hypothesized that exosome-like vesicles are present in hypopharyngeal gland secretomal products (honey, royal jelly and bee pollen), and participate in their known antibacterial and pro-regenerative effects. We developed an isolation protocol based on serial centrifugation and ultracentrifugation steps and demonstrated the presence of protein-containing exosome-like vesicles in all three bee-derived products.

Nonmotile Single-Cell Migration as a Random Walk in Nonuniformity: The "Extreme Dumping Limit" for Cell-to-Cell Communications.

In the present work, we model single-cell movement as a random walk in an external potential observed within the extreme dumping limit, which we define herein as the extreme nonuniform behavior observed for cell responses and cell-to-cell communications. Starting from the Newton-Langevin equation of motion, we solve the corresponding Fokker-Planck equation to compute higher moments of the displacement of the cell, and then we build certain quantities that can be measurable experimentally. We show that, each time, the dynamics depend on the external force applied, leading to predictions distinct from the standard results of a free Brownian particle.

Association between Alzheimer's Disease and Oral and Gut Microbiota: Are Pore Forming Proteins the Missing Link?

Alzheimer's disease (AD) is a neurodegenerative condition affecting millions of people worldwide. It is associated with cerebral amyloid-β (Aβ) plaque deposition in the brain, synaptic disconnection, and subsequent progressive neuronal death. Although considerable progress has been made to elucidate the pathogenesis of AD, the specific causes of the disease remain highly unknown.

Quantitative nanohistological investigation of scleroderma: an atomic force microscopy-based approach to disease characterization.

Scleroderma (or systemic sclerosis, SSc) is a disease caused by excess crosslinking of collagen. The skin stiffens and becomes painful, while internally, organ function can be compromised by the less elastic collagen. Diagnosis of SSc is often only possible in advanced cases by which treatment time is limited.

Mechanics of Bacterial Cells and Initial Surface Colonisation.

The mechanical properties of bacterial cells play an important role in crucial bacterial processes such as cell growth, colonisation and biofilm formation. Recent developments in the field of nanotechnology and atomic force microscopy (AFM) have made it possible to observe, characterise and understand the nanomechanic behaviour of live bacterial cells as never before. Unlike traditional techniques, AFM makes it possible to employ living bacteria in their physiological environment with minimal or no sample preparation.

Probing the nanoadhesion of Streptococcus sanguinis to titanium implant surfaces by atomic force microscopy.

As titanium (Ti) continues to be utilized in great extent for the fabrication of artificial implants, it is important to understand the crucial bacterium-Ti interaction occurring during the initial phases of biofilm formation. By employing a single-cell force spectroscopy technique, the nanoadhesive interactions between the early-colonizing Streptococcus sanguinis and a clinically analogous smooth Ti substrate were explored. Mean adhesion forces between S.

A simple and robust method for pre-wetting poly (lactic-co-glycolic) acid microspheres.

Poly (lactic-co-glycolic) acid microspheres are amenable to a number of biomedical procedures that support delivery of cells, drugs, peptides or genes. Hydrophilisation or wetting of poly (lactic-co-glycolic) acid are an important pre-requisites for attachment of cells and can be achieved via exposure to plasma oxygen or nitrogen, surface hydrolysis with NaOH or chloric acid, immersion in ethanol and water, or prolonged incubation in phosphate buffered saline or cell culture medium. The aim of this study is to develop a simple method for wetting poly (lactic-co-glycolic) acid microspheres for cell delivery applications.