Ros Tárraga P is a Biotechnology graduated at Universidad Miguel Hernández of Elche (UMH). Actually, he is a pre-doctoral student at Universidad Católica San Antonio de Murcia (UCAM), and he is working in the design and development of new bioactive materials and their use in the field of bone tissue regeneration. He is studying the physical characterization of Si-Ca-P-based scaffolds and their effect on the adult human Mesenchymal Stem Cells (ahMSC) behavior.
Biomaterials are used in tissue engineering with the aim to repair tissues and organs. Since stem cells can be readily isolated, expanded and transplanted, their application in cell-based therapies is a major focus of research. We test the behaviour of ahMSCs on silk fibroin based biomaterial in order to use it for tissue repair. Silk fibroin mesh was obtained by electrospinning of fibroin obtained from cocoons of silkworms. ahMSCs were obtained by aspiration of ileac crest from healthy volunteer and isolated by gradient ficoll (SEPAX™) and cultivated in α-MEM supplemented with FCS and penicillin G /streptomycin sulphate (100 U ml-1 and 100 g ml-1). 1.0 x 105 ahMSCs were seeded onto the material in 24-well plates and analyzed at 72 h and 1, 2, 3, and 4 weeks. The growth rate, morphology, adherence was analized at different times using ImageJ ™ software, PhCM and SEM. At 72h, the ahMSCs cultured had a flattened polygonal appearance with spread cytoplasmatic extensions. Later, at 1 week, the adhesion was enhanced by means of multiple philopodia. Abundant extracellular matrix was observed occupying intercellular gaps. At 3-4 weeks, the cells became confluent forming an homogeneous monolayer almost coating the whole of the mesh. The cells showed a strong adhesion to the microfiber and proliferated in a short period of time (1 week). At the confluence, collagen-like lattices occupied the intercellular gaps. No cytotoxicity phenomena was detected. So, we can suggest that the material is a suitable substrate for ahMSCs growth and stem cell-based tissue engineering.
Rubén Rabadán Ros is a biologist in the University of Murcia (UMU) and he have a MSc degree in Molecular Biology and Biotechnology by the same university. Currently he is a PhD student in Biomedical Sciences at Saint Anthony Catholic University of Murcia (UCAM), developing scaffolds based on the C2S-TCP phase diagram and their in vitro and in vivo study.
To take advantage of the beneficial effect of Si, novel materials with compositions derived from the Dicalcium Silicate-Tricalcium phosphate (C2S-TCP) phase diagram were developed (EC1 31wt%TCP-69wt%C2S; EC2 59.5wt%TCP-40.5wt%C2S; EC3 83wt% TCP-17wt% C2S). Phase composition effect on their ability to support adult human mesenchymal stem cells (ahMSCs) growth and osteogenic differentiation induction in presence of DMEM or an osteogenic medium (OM) was therefore investigated. The ahMSCs were examined at 1, 2, 3, 4 weeks in culture, for the osteoblast phenotypic markers alkaline phosphatase (ALP), osteocalcin (OCN), osteopontin (OPN) and cell surface marker CD105. At week 2, the population of ALP + cells was similar for all samples. At week 4, the proportion of cells ALP + increased significantly in EC2 samples. At week 1, ahMSCs expressed the CD105 marker in all samples, but in OM CD105 expression decrease significantly for EC1 and EC2 samples. Treatment with OM increased the gene expression of the bone extracellular matrix proteins OPN and OCN as determined by RT-PCR analysis. Addition of OM changed significantly the results: best result for ALP was obtained at 28 days for EC2 biomaterial; best OCN, OPN and RUNX2 expression was obtained at 21 days for EC2 material; best CD105 surface expression decrease on 21 days in OM for all samples. This results overlap because the gene expression have to increase before protein production, and confirms our hypothesis as we don’t expected to see changes before week 3, and we hypothesize that OM effect summarizes to the biomaterial differentiation induction potential.