## 1 Introduction  
Regenerative medicine in dentistry is applied in biotooth/bioroot engineering, regeneration of periodontal defects, and dentin-pulp regeneration strategies [1] by using a combination of scaffold, growth factors, and stem cells [2]. Within such context, polymers and commercially pure titanium membranes are used for dental implants and orthopedic surgery as scaffolds for engendering endogenous cells' proliferation and migration, however they are bioinert materials that do not stimulate bone formation (i.e., they are not osteoinductive) and do not directly bond to bone [3]. This is why titanium surfaces, most commonly used in dental implants, have been engineered to determine the appropriate scaffold properties (e.g., porosity, surface geometry, and mechanical strength) in order to support the necessary cell activity to promote bone regrowth by the host cells [4].  
Among the cell types used for bone regenerative purposes, stem cells are considered more than a promising strategy to achieve the regeneration of large alveolar bone defects, particularly to provide stable and accelerated bone formation as well as enhanced osseointegration in dental implant treatments. Mesenchymal stem cells (MSCs) have been identified as a significant cell source for regenerative medicine due to their self-renewal, easy growth in vitro that allows them to expand, their differentiation capacities, and immunomodulatory properties [5]. Although MSCs are classically derived from the bone marrow (BM), other sources are, among the others, many tissues in the orofacial region, the adipose tissue, and the placental tissue. The application of MSCs derived from the amniotic membrane is increasingly recognized as a therapeutic option for the purposes of regenerative medicine and tissue engineering, because of the easiness of their acquisition, reduced donor damage, multipotency, low immune response, and acceptable ethical issue [6]. Human amniotic mesenchymal stromal cells (hAMSCs) have stem cell-like properties and are able to differentiate into cells derivable from each of the three germ layers, including osteogenic, chondrogenic, and adipogenic lineages [7; 8; 9; 10; 11]. Similar to BM-MSCs, hAMSCs express typical mesenchymal antigens such as CD29, CD73, and CD105 and lack hematopoietic markers CD34, CD45, and CD14. The application of hAMSCs to tissue engineering and cell replacement studies has shown their therapeutic potential in different clinical fields, including dentistry, orthopedics, skin reconstruction, as well as in liver, cardiac, and respiratory diseases [12; 13; 14].  
A limit in using MSCs derived from the classical source, i.e., the BM, is their dependence on donors [15]. The number of BM-MSCs declines with age, as well as their fitness, explored as an increase in reactive oxygen species and oxidative stress, is reduced with ageing [16]. Another study demonstrated an age-dependent reduction in the proliferation and differentiative capacity towards the osteoblast lineage in BM-MSCs [17]. Also, the disease state may affect the collection of sufficient healthy autologous BM for transplantation, as well as their functionality [18; 19; 20].  
Since no studies have been carried out to reveal if hAMSCs features can be modified by age and pathology, we have undertaken a study to ascertain whether mother's age and pre-eclampsia (PE) can affect the functional behavior of hAMSCs. We have chosen PE since it is a relatively common pregnancy disorder that may threaten the survival of both mother and baby [21]. Some evidence highlighted that PE is a systemic vascular disorder whose hallmark is a disturbed angiogenic balance [22]. Our findings show that hAMSCs are affected by age and PE, in particular PE affects their adhesion to titanium surfaces, implying that PE hAMSCs may be not osteoconductive when used in combination with titanium-based dental implants.