Logo: to the web site of Uppsala University

Addressing the challenge of bone tissue regeneration requires creating an optimal microenvironment that promotes both osteogenesis and angiogenesis. Electroconductive scaffolds have emerged as promising solutions for bone regeneration; however, existing conductive polymers often lack biofunctionality and biocompatibility. In this study, we synthesized poly(3,4-ethylenedioxythiophene) nanoparticles (PEDOT NPs) using chemical oxidation polymerization and incorporated them into gelatin/hyaluronic acid/hydroxyapatite (Gel:HA:HAp) scaffolds to develop Gel:HA:HAp:PEDOT-NP scaffolds. Morphological analysis by scanning electron microscopy (SEM) showed a honeycomb-like structure with pores of 228–250 μm in diameter. The addition of the synthesized PEDOT NPs increased the conductive capabilities of the scaffolds to 1 × 10−6 ± 1.3 × 10−7 S/cm. Biological assessment of PEDOT NP scaffolds using human foetal osteoblastic 1.19 cells (hFOB), and human bone marrow-derived mesenchymal stem cells (hBMSCs) revealed enhanced cell proliferation and viability compared to control scaffold without NPs, along with increased osteogenic differentiation, evidenced by higher levels of alkaline phosphatase activity, osteopontin (OPN), alkaline phosphatase (ALP), and osteocalcin (OCN) expression, as observed through immunofluorescence, and enhanced expression of osteogenic-related genes. The conductive scaffold shows interesting mineralization capacity, as shown by Alizarin red and Osteoimage staining. Furthermore, PEDOT-NP scaffolds promoted angiogenesis, as indicated by improved tube formation abilities of human umbilical vein endothelial cells (HUVECs), especially at the higher concentrations of NPs. Overall, our findings demonstrate that the integration of PEDOT NPs scaffold enhances their conductive properties and promotes cell proliferation, osteogenic differentiation, and angiogenesis. Gel:HA:HAp:PEDOT-NP scaffolds exhibit promising potential as efficient biomaterials for bone tissue regeneration, offering a potential engineered platform for clinical applications.

Recent complications on the use of polypropylene meshes for hernia repair has led to the development of meshes or films, which were based on resorbable polymers such as polycaprolactone (PCL), polylactic acid (PLA) and poly(lactic-co-glycolic acid) (PLGA). These materials are able to create suitable bioactive environment for the growth and development of cells. In this research, we mainly focused on the relations among structure, mechanical performance and biocompatiblity of PCL/PLA and PCL/PLGA and blends prepared by solution casting. The films were characterized regarding the chemical structure, morphology, physicochemical properties, cytotoxicity, biocompatibility and cell growth. All the films showed high tensile strength ranging from 9.5 to 11.8 MPa. SAXS showed that the lamellar stack structure typical for PCL was present even in the blend films while the morphological parameters of the stacks varied slightly with the content of PLGA or PLA in the blends. WAXS indicated preferential orientation of crystallites (and thus, also the lamellar stacks) in the blend films. In vitro studies revealed that PCL/PLGA films displayed better cell adhesion, spreading and proliferation than PCL/PLA and PCL films. Further the effect of blending on the degradation was investigated, to understand the significant variable within the process that could provide further control of cell adhesion. The results showed that the investigated blend films are promising materials for biomedical applications.

Hydrogel based matrices and titanium dioxide (TiO2) nanoparticles (NPs) are well established materials in bone tissue engineering. Nevertheless, there is still a challenge to design appropriate composites with enhanced mechanical properties and improved cell growth. Progressing in this direction, we synthesized nanocomposite hydrogels by impregnating TiO2 NPs in a chitosan and cellulose-based hydrogel matrix containing polyvinyl alcohol (PVA), to enhance the mechanical stability and swelling capacity. Although, TiO2 has been incorporated into single and double component matrix systems, it has rarely been combined with a tri-component hydrogel matrix system. The doping of NPs was confirmed by Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy and small- and wide-angle X-ray scattering. Our results showed that incorporation of TiO2 NPs improved the tensile properties of the hydrogels significantly. Furthermore, we performed biological evaluation of scaffolds, swelling degree, bioactivity assessment, and hemolytic tests to prove that all types of hydrogels were safe for use in the human body. The culturing of human osteoblast-like cells MG-63 on hydrogels showed better adhesion of cells in the presence of TiO2 and showed increasing proliferation with increasing amount of TiO2. Our results showed that the sample with the highest TiO2 concentration, CS/MC/PVA/TiO2 (1 %) had the best biological properties.