Microporosity Clustering Assessment in Calcium Phosphate Bioceramic Particles

Abstract

There has been an increase in the application of different biomaterials to repair hard tissues. Within these biomaterials, calcium phosphate (CaP) bioceramics are suitable candidates, since they can be biocompatible, biodegradable, osteoinductive, and osteoconductive. Moreover, during sintering, bioceramic materials are prone to form micropores and undergo changes in their surface topographical features, which influence cellular physiology and bone ingrowth. In this study, five geometrical properties from the surface of CaP bioceramic particles and their micropores were analyzed by data mining techniques, driven by the research question: what are the geometrical properties of individual micropores in a CaP bioceramic, and how do they relate to each other? The analysis not only shows that it is feasible to determine the existence of micropore clusters, but also to quantify their geometrical properties. As a result, these CaP bioceramic particles present three groups of micropore clusters distinctive by their geometrical properties. Consequently, this new methodological clustering assessment can be applied to advance the knowledge about CaP bioceramics and their role in bone tissue engineering.

Analysis of cell-biomaterial interaction through cellular bridge formation in the interface between hGMSCs and CaP bioceramics

“…In the current study high proliferation levels were observed until the third week in culture (Fig. 3 C), which is mainly achieved due to the CaP composition and geometry, combining micro and macropores, as previously described in 37 . The competent cellular adhesion to the CaP bioceramic was confirmed by the elongated fusiform cellular morphology shown by the SEM panels (Fig.…”

“…In this scenario, cell attachment depends on the bioceramic´s surface and on its geometrical properties and composition 1 , aspects that may influence cellular metabolism and ionic exchange critical for migration and proliferation, but before that happens adhesion to the substrate needs to be strong and stable 36 , 41 . The CaP bioceramic used in this study presents geometrical features combining macro and micropores, with different pore size, distribution and clustering, as previously described by 37 (Fig. 1 A).…”

“…All these bioceramic parameters are known to play a crucial role in cell growth and adhesion, nutrient exchange, cellular proliferation and the formation of a fibrose structured net, prior stage for the formation of cellular differentiation 36 . Hence, due to the importance of morphological and geometrical properties of CaP bioceramics on osteogenic differentiation 8 , 29 further studies are required to develop a more cost effective osteogenic strategies to promote bone regeneration 37 , 38 . So, to proceed in clinical applications integrating both CaP bioceramics and hGMSCs, a more comprehensive knowledge relating the microarchitecture of the bioceramic with the efficiency of the formation of an optimal cellular structure is required.…”

Morphological and porosity changes in primary enamel surface after an in vitro demineralization model

“…Subsequently, SEM images were processed by ImageJ software, as previously reported in dental materials evaluations (Coldebella et al, 2011; Sezgin & Sankur, 2004). This method of binarization thresholding has been employed to separate objects from the back of the photomicrograph to obtain porosity values considering the orifices of pores in each image to obtain the total number of porosities in a certain area (Coldebella et al, 2011; Sezgin & Sankur, 2004; Vallejos Baier et al, 2019).…”

“…Then, ImageJ software (Rasband WS, ImageJ; US National Institutes of Health, Bethesda, MD, USA) was employed to isolate enamel micropores and perform the measurements (Xu, Chan & Tirunagari, 2007; Vallejos Baier et al, 2019) through the threshold tool. Subsequently, ROI was turned to a binary image (following a similar protocol previously validated) where black pixels represented pores (Vallejos Baier et al, 2019; Xuet al, 2007). The menu commands allow the measurement of parameters to be evaluated on image data.…”