Liposomes embedded with differentiating factors as a new strategy for enhancing DPSC osteogenic commitment

Abstract

Human dental pulp stem cell (DPSC) differentiation toward the osteoblastic phenotype is enhanced when culture media are supplemented with differentiating factors, i.e. ascorbic acid, β-glycerophosphate and dexamethasone. Liposomes, spherical vesicles formed by a phospholipid bilayer, are frequently used as carriers for drugs, growth factors and hydrophobic molecules. The aim of this work was to speed up DPSC commitment to the osteogenic lineage by embedding differentiating factors within liposomes. Firstly, liposomes were prepared by rehydrating a phospholipidic thin film and characterised in terms of dimensions. Secondly, liposome-exposed DPSCs were characterised by their immunophenotypic profile. Levels of CD90 were significantly decreased in the presence of liposomes filled with ascorbic acid, β-glycerophosphate and dexamethasone (Lipo-Mix) with respect to normal differentiation medium (DM), while CD73 and CD29 expression were enhanced, suggesting osteogenic commitment. Additionally, an appreciable extracellular matrix deposition is detected. Thirdly, the Lipo-Mix formulation better increases alkaline phosphatase activity and levels of Collagen I secretion with respect to DM. In parallel, the new liposome formulation is capable of decreasing the release of H2O2 and of triggering a precocious antioxidant cell response, redressing the redox balance required upon mesenchymal stem cell commitment to osteogenesis. It can be therefore hypothesised that Lipo-Mix could represent a suitable tool for clinical regenerative purposes in the field of tissue engineering by speeding up DPSC osteogenic commitment, mineralised matrix deposition and remodelling.

The Open Cell Form of 3D-Printed Titanium Improves Osteconductive Properties and Adhesion Behavior of Dental Pulp Stem Cells

“…The DPSC varied modulation of proteins related to cell attachment and proliferation reflects the observed dissimilar behaviour of adhesion and growth ascribable to the different titanium surfaces. The collagen-binding integrin β1 is broadly known as a regulator of osteoblast differentiation and proliferation on titanium substrates with different roughness characteristics [ 24 ], and it has been found to be time-dependently increased during the osteogenic commitment of DPSCs [ 25 ]. On the other hand, focal adhesions (FAs) act as a bridge between integrin-ECM connection and the cytoskeleton, and are required for morphogenesis and migration [ 26 ].…”

Relevance of Cellular Redox Homeostasis for Vital Functions of Human Dental Pulp Cells

“…As for CD140a (platelet-derived growth factor receptor A, PDGFRα), it is reported to identify a population of progenitor cells of neural crest origin and it has been included in this investigation due to its weak expression found in cells previously isolated from the dental pulp-interface and immunophenotypically characterized [ 20 ]. The positivity of MSCs from the dental pulp to the various cell markers is differentially modulated under the odontogenic commitment [ 17 ]. Firstly, CD90 (Thy-1) is found decreased in a time-dependent manner, meaning that cell stemness is reduced towards the osteogenic differentiation [ 17 ].…”

“…The positivity of MSCs from the dental pulp to the various cell markers is differentially modulated under the odontogenic commitment [ 17 ]. Firstly, CD90 (Thy-1) is found decreased in a time-dependent manner, meaning that cell stemness is reduced towards the osteogenic differentiation [ 17 ]. Secondly, the ecto-5′-nucleotidase CD73 is upregulated under osteogenic conditions and highly expressed in odontoblasts, as it is involved in adenosine production and in the enhancement of bone metabolism through the Wntβ-catenin signaling [ 29 ].…”

“…Our group has previously observed molecular pathways underlying the intracellular balance between redox homeostasis and extracellular matrix mineralization of human pulp cells (HPCs), emphasizing IL-6 as one of the major players involved [ 15 , 16 ]. Furthermore, a redox control through the ROS-activated MAPKs (mitogen-activated protein kinases) signaling has been highlighted under the osteogenic commitment of HPCs in vitro [ 17 ].…”

The Effect of Liposomal Curcumin as an Anti-Inflammatory Strategy on Lipopolysaccharide e from Porphyromonas gingivalis Treated Endothelial Committed Neural Crest Derived Stem Cells: Morphological and Molecular Mechanisms

“…Hydration of the lipid film was carried out by adding PBS buffer (pH 7.4) at room temperature with constant agitation for 30 min. The obtained multivesicular suspension was sonicated for 30 min and then subjected to sterilization under UV lamp for 2 h [ 65 , 66 ]. An appropriate amount of Cur in DMSO was added to the liposomal suspension to obtain a POPC to Cur molar ratio of 25:1.…”