Structure‐dependent behaviours of skin layers studied by atomic force microscopy

Abstract

The multilayer skin provides the physical resistance and strength against the environmental attacks, and consequently plays a significant role in maintaining the mammalian health. Currently, optical microscopy (OM) is the most common method for the research related to skin tissues while with the drawbacks including the possibility of changing the native morphology of the sample with the addition of the chemical or immunological staining and the restricted resolution of images for the direct observation of the tissue structures. To investigate if the function of each tissue is structure-dependent and the how the injured skin returns to the intact condition, we applied atomic force microscopy (AFM) on the sectioned mice-skin to reveal the tissue structures with a nanoscale resolution. From the outermost stratum to the inner layer of the skin tissue, the respectively laminated, fibrous, and brick-like structures were observed and corresponded to various functions. Due to the mechanical differences between the tissue constituents and their boundaries, the sizes and arrangements of the components were characterised and quantified by the mechanical mapping of AFM, which enabled the analytical comparisons between tissue layers. For the wound model, the skin tissues were examined with the initial formation of blood vessels and type-I collagen, which agreed with the stage of healing process estimated by OM but showed more detail information about the evolution of proteins among the skin. In conclusion, the characterisation of the components that consist of skin tissue by AFM enables the connection of the tissue function to the corresponded ultrastructure.

Identification of Characteristic Macromolecules of Escherichia coli Genotypes by Atomic Force Microscope Nanoscale Mechanical Mapping

“…In addition, the bacterial surface was found to be composed of circular components that were characterized to be less adhesive when compared to the surrounding matrix. This observation is similar to our previous findings on the tissue layers of mice skin, and the recurring and comparable grains were considered to be macromolecules, whose structure is more dense and consistent than those seen in the intermolecular region so that the differences in adhesion performance could be easily sensed [ 12 ]. The outermost layer of the cellular envelope in Gram-negative bacteria is a layer of self-assembly proteins, as illustrated in Fig.…”

Importance of endogenous extracellular matrix in biomechanical properties of human skin model

“…AFM applied on sectioned mice-skin enables the connection of the tissue function to the corresponded ultrastructure and revealed tissue structures with a nanoscale resolution, especially in a wound model [34].…”

Aplicabilidade da estereologia e microscopia de força atômica à pesquisa dermatológica veterinária (revisão de literatura)

“…Apesar desses benefícios, ainda é escassa sua utilização em dermatologia veterinária, limitando-se a estudos cicatriciais em murinos (RAGHUWANSHI et al, 2017). Em dermatologia humana, recentemente descreveu-se a composição nanoestrutural da pele (ECKERSLEY et al, 2018), corneócitos (DANZBERGER et al, 2018) e fibras colágenas (QUIGLEY et al, 2018) A rigidez da epiderme, a espessura, orientação e periodicidade das fibras de colágeno, presentes na derme papilar humana, bem como suas particularidades nanoestruturais, foram recentemente mensuradas (OLEJNIK, A.;NOWAK, I 2017;PEÑUELA et al, 2018;CHANG et al, 2017). Essas descrições são importantes para determinação de parâmetros de normalidade, haja visto que entidades nosológicas distintas podem alterar as propriedades mecânicas da pele e seus componentes, as quais podem ser identificadas por AFM (VIELMUTH, 2018).…”

“…Avaliações morfológicas constituem etapa fundamental de quaisquer pesquisas dermatológicas veterinárias por permitirem a descrição estrutural dos elementos que compõem a pele, favorecendo a padronização de características de normalidade intraespecíficos (KAMP et al, 2009). De uma forma geral, as camadas e estratos da pele têm sido objeto de muitos estudos morfológicos e ultraestruturais, tanto pela variabilidade entre as espécies, quanto às funções imunológica, farmacodinâmica e farmacocinética cutânea (HUSSAIN, 2019;CHANG, 2017;AGARWAL, 2019;LOGGER, 2019). Em medicina veterinária, dado o elevado número de espécies estudadas, tais características tornam-se ainda mais relevantes, haja visto que as variações de celularidade, densidade celular, volume celular e tecidual, influenciam na fisiologia cutânea e, consequentemente, na rotina clínica para a espécie (KAMP et al, 2011).…”