Nanocrystalline Hydroxyapatite Loaded with Resveratrol in Colloidal Suspension Improves Viability, Metabolic Activity and Mitochondrial Potential in Human Adipose-Derived Mesenchymal Stromal Stem Cells (hASCs)

In response to the demand for new multifunctional materials characterized by high biocompatibility, hydrogel (HG) nanocomposites as a platform for bioactive compound delivery have been developed and fabricated. A specific crosslinking/copolymerization chemistry was used to construct hydrogels with a controlled network organization. The hydrogels were prepared using 3,6-anhydro-α-l-galacto-β-d-galactan (galactose hydrogel) together with resveratrol (trans-3,5,4'-trihydroxystilbene) and calcium hydroxyapatite nanoparticles. The resveratrol was introduced in three different concentrations of 0.1, 0.5, and 1 mM. Nanosized calcium hydroxyapatite was synthesized by a microwave-assisted hydrothermal technique, annealed at 500 °C for 3 h, and introduced at a concentration 10% (m/v). The morphology and structural properties of Ca10(PO₄)₆(OH)₂ and its composite were determined by using XRPD (X-ray powder diffraction) techniques, as well as the absorption and IR (infrared) spectroscopy. The average nanoparticle size was 35 nm. The water affinity, morphology, organic compound release profile, and cytocompatibility of the obtained materials were studied in detail. The designed hydrogels were shown to be materials of biological relevance and of great pharmacological potential as carriers for bioactive compound delivery. Their cytocompatibility was tested using a model of human multipotent stromal cells isolated from adipose tissue (hASCs). The biomaterials increased the proliferative activity and viability of hASCs, as well as reduced markers of oxidative stress. In light of the obtained results, it has been thought that the designed materials meet the requirements of the tissue engineering triad, and may find application in regenerative medicine, especially for personalized therapies.

Fabrication, Characterization, and Cytotoxicity of Thermoplastic Polyurethane/Poly(lactic acid) Material Using Human Adipose Derived Mesenchymal Stromal Stem Cells (hASCs)

Thermoplastic polyurethane (TPU) and poly(lactic acid) are types of biocompatible and degradable synthetic polymers required for biomedical applications. Physically blended (TPU+PLA) tissue engineering matrices were produced via solvent casting technique. The following types of polymer blend were prepared: (TPU+PLA) 7:3, (TPU+PLA) 6:4, (TPU+PLA) 4:6, and (TPU+PLA) 3:7. Various methods were employed to characterize the properties of these polymers: surface properties such as morphology (scanning electron microscopy), wettability (goniometry), and roughness (profilometric analysis). Analyses of hydrophilic and hydrophobic properties, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) of the obtained polymer blends were conducted. Tensile tests demonstrated that the blends exhibited a wide range of mechanical properties. Cytotoxicity of polymers was tested using human multipotent stromal cells derived from adipose tissue (hASC). In vitro assays revealed that (TPU+PLA) 3:7 matrices were the most cytocompatible biomaterials. Cells cultured on (TPU+PLA) 3:7 had proper morphology, growth pattern, and were distinguished by increased proliferative and metabolic activity. Additionally, it appeared that (TPU+PLA) 3:7 biomaterials showed antiapoptotic properties. hASC cultured on these matrices had reduced expression of Bax-α and increased expression of Bcl-2. This study demonstrated the feasibility of producing a biocompatible scaffold form based on (TPU+PLA) blends that have potential to be applied in tissue engineering.