## 1 Introduction
This process is known as mechano-transduction and, most probably, the majority of eukaryotic cells are mechanosensitive, playing a key role in the growth and regeneration of all the living tissues. Essentially, there are three main components involved in this mechanism: focal adhesion, mechanosensors, and signaling specimens which are able to generate changes at gene levels and protein expression profiles. However, this is a mid-term process, with a timescale that varies from seconds to several weeks. The first stage is the activation of mechanosensors which occurs in a few seconds, followed by the generation of genetic changes in the following hours, the directing of cell functions in the following days and finally, permanent changes in cellular phenotype and differentiation pathways in the following weeks [30]. It was demonstrated that cells are able to react to a multitude of mechanical cues, including static ones, such as mechanical or chemical properties (e.g., surface biochemistry, topography, or stiffness). One key element in mechano-transduction is the integrin-mediated signaling as a result of being the core receptors for ECM-related proteins such as fibronectin, laminin, or collagen. As previously stated, integrins are made of subunits, 18 alpha and 8 beta subunits that have their own affinity for multiple peptides. The intracellular part of integrins is in continuous interaction with cytoplasmatic proteins making possible the development of focal adhesion complexes that are able to provide a direct connection between the outer matrix and the cytoskeleton [33; 34; 35]. \begin{table}
\begin{tabular}{c c c} \hline
**Collagens** & **Non-Collagenous Proteins** & **Proteoglycans/Glycosaminoglycans** \\ \hline  & Osteonectin (SPARC) & Decorin \\ Collagen type I & Osteocalcin (bone-Gla protein) & Lumican \\ Collagen type III & Osteopontin & Biglycan \\  & Sialoprotein & Epiphycan \\ \hline \end{tabular}
\end{table} 
Table 1: The main components of bone organic extracellular matrix (ECM) [36; 37]. Taking all these aspects into account, research has been focused in the last decades on controlling the stem cell niche in tissue engineering, and on promoting the desired cellular response for various cellular phenotypes. This strategy seemed to be promising in terms of guiding the tissue response in contact with specific stimuli in various fields. Therefore, the scaffold design should be focused on multiple aspects including, but not limited to, material type, surface, topography, architecture, antimicrobial properties, chemical and mechanical properties, and ability to induce the bone forming processes. Commonly, the manufacture of a tissue-engineered bone consists of three components: scaffold, stem cells, and molecules which can direct the cellular activity (i.e., growth factors) [38; 39]. When it comes to scaffold construction, a variety of materials have been used over time for bone repair purposes, such as ceramics, polymers, bioglasses, and hybrid or composite materials. However, a biomimetic scaffold should consist of an inorganic component which is able to mimic the ECM architecture, should present high porosity for promoting cellular anchorage and proper degradation rate, and should encourage bone formation and osteoblastic differentiation (to be osteoinductive) [40].