Novel Scaffold Based on Chitosan Hydrogels/Phthalated Cashew Gum for Supporting Human Dental Pulp Stem Cells.

Hydrogels are structures that have value for application in the area of tissue engineering because they mimic the extracellular matrix. Naturally obtained polysaccharides, such as chitosan (CH) and cashew gum, are materials with the ability to form polymeric networks due to their physicochemical properties. This research aimed to develop a scaffold based on chitosan and phthalated cashew tree gum and test it as a support for the growth of human mesenchymal stem cells. In this study, phthalation in cashew gum (PCG) was performed by using a solvent-free route. PCG-CH scaffold was developed by polyelectrolyte complexation, and its ability to support adherent stem cell growth was evaluated. The scaffold showed a high swelling rate. The pore sizes of the scaffold were analyzed by scanning electron microscopy. Human dental pulp stem cells (hDPSCs) were isolated, expanded, and characterized for their potential to differentiate into mesenchymal lineages and for their immunophenotypic profile. Isolated mesenchymal stem cells presented fibroblastoid morphology, plastic adhesion capacity, and differentiation in osteogenic, adipogenic, and chondrogenic lineages. Mesenchymal stem cells were cultured in scaffolds to assess cell adhesion and growth. The cells seeded on the scaffold showed typical morphology, attachment, and adequate distribution inside the matrix pores. Thus, cells seeded in the scaffold may improve the osteoinductive and osteoconductive properties of these biomaterials.

Development of castor polyurethane scaffold (Ricinus communisL.) and its effect with stem cells for bone repair in an osteoporosis model.

The development of 'smart' scaffolds has achieved notoriety among current prospects for bone repair, especially for chronic osteopathy, such as osteoporosis. Millions of individuals in the world suffer from poor bone healing due to osteoporosis. The objective of this work was to produce and characterize castor polyurethane (PU) scaffolds (Ricinus communisL.)andevaluate itsin vitrobiocompatibility with stem cells and osteoinductive effectin vivoon bone failures in a leporid model of osteoporosis. The material was characterized using Fourier-transform infrared spectroscopy, thermogravimetric analysis, SEM, and porosity analysis. Then, the biocompatibility was assessed by adhesion using SEM and cytotoxicity in a 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium assay. The osteoinductive effectin vivowas determined in bone defects in rabbit tibias (Oryctolagus cuniculus) submitted to castor PU scaffold, castor PU scaffold associated with stem cells, and negative control, after four and eight weeks, evaluated by computed microtomography and histopathology. The scaffolds were porous, with an average pore size of 209.5 ± 98.2 µm, absence of cytotoxicity, and positive cell adhesivenessin vitro.All the animals presented osteoporosis, characterized by multifocal osteoblastic inactivity and areas of mild fibrosis. There were no statistical differences between these treatments in the fourth week of treatment. In the eighth week, the treatment with castor PU scaffold alone induced more significant bone formation when compared to the other groups, followed by treatment with an association between castor PU scaffold and stem cells. The castor PU scaffold was harmless to cell culture, favoring cell adhesiveness and proliferation, in addition to inducing bone neoformation in osteoporotic rabbits.

Characterization and plasticity of wharton's jelly mesenchymal stem cells of goat

Mesenchymal stem cells (MSCs), obtained from several anatomical sites, have already been described, characterized and used in therapeutic models for tissue repair. The umbilical cord mesenchymal stem cells, represented by cells from arteries and veins walls, as well as Wharton's jelly are easy to be obtained, highly available, require no invasive procedure, do not present risk to donors and do not present ethical limitation. The aim of this research was to analyze the plasticity of Wharton's jelly mesenchymal stem cells (WJ-MSCs) of goat, evaluating their behavior in vitro and characterizing them immunophenotypically. Thus, tests were performed on colony forming units, viability and cell growth curve, flow cytometry analysis and plasticity potential. Goat umbilical cord matrix cells exhibited fibroblastoid morphology with colony formation and self-renewal ability, always maintaining their undifferentiated state up to the eighth passage (P8). The growth curve kinetics exhibited the LAG, LOG, and DECAY phases, without displaying a PLATEAU phase. The plasticity assay demonstrated positive differentiation for osteogenic, adipogenic and chondrogenic lines, characterized by the synthesis of intracytoplasmic granules or extracellular matrix with the presence of calcium, lipids and proteoglycans. Flow cytometry demonstrated the expression of CD90 and CD105; absence of CD14 expression. It is concluded that the cell population isolated from the Wharton's jelly of goat constitutes a representative sample of mesenchymal stem cells, with great possibilities in the field of regenerative and reproductive medicine.