David García-Bernal

The effects of Ca2SiO4-Ca3(PO4)2 ceramics on adult human mesenchymal stem cell viability, adhesion, proliferation, differentiation and function.

Bioceramic samples with osteogenic properties, suitable for use in the regeneration of hard tissue, were synthesized. The materials consisting of α-tricalcium phosphate (αTCP) and also αTCP doped with either 1.5 wt.% or 3.0 wt.% of dicalcium silicate (C2S) in the system Dicalcium Silicate-Tricalcium Phosphate (C2S-TCP) were obtained by solid state reaction. All materials were composed of a single phase, αTCP in the case of a pure material, or solid solution of C2S in αTCP (αTCPss) for the doped αTCP. Viability, proliferation and in vitro osteoinductive capacity were investigated by seeding, adult mesenchymal stem cells of human origin (ahMSCs) which were CD73(+), CD90(+), CD105(+), CD34(-) and CD45(-) onto the 3 substrates for 30 days. Results show a non-cytotoxic effect after applying an indirect apoptosis test (Annexin V/7-AAD staining), so ahMSCs adhered, spread, proliferated and produced extracellular matrix (Heparan-sulfate proteoglycan (HS) and osteopontin (OP)) on all the ceramics studied. Finally, the cells lost the cluster differentiation marker expression CD73, CD90 y CD105 characteristic of ahMSCs and they showed an osteoblastic phenotype (Alkaline phosphatase activity (ALP), Osteocalcin production (OC), Collagen type I expression (Col-I), and production of mineralization nodules on the extracellular matrix). These observations were more evident in the αTCP ceramic doped with 1.5 wt.% C2S, indicating osteoblastic differentiation as a result of the increased concentration of solid solution of C2S in αTCP (αTCPss). Overall, these results suggest that the ceramics studied are cytocompatible and they are able to induce osteoblastic differentiation of undifferentiated ahMSCs.

Biocompatibility of New Pulp-capping Materials NeoMTA Plus, MTA Repair HP, and Biodentine on Human Dental Pulp Stem Cells

Introduction: The aim of the present study was to evaluate the in vitro cytotoxicity of MTA Repair HP, NeoMTA Plus, and Biodentine, new bioactive materials used for dental pulp capping, on human dental pulp stem cells (hDPSCs). Methods: Biological testing was carried out in vitro on hDPSCs. Cell viability and cell migration assays were performed using eluates of each capping material. To evaluate cell morphology and cell attachment to the different materials, hDPSCs were directly seeded onto the material surfaces and analyzed by scanning electron microscopy. The chemical composition of the pulp‐capping materials was determined by energy‐dispersive X‐ray and eluates were analyzed by inductively coupled plasma‐mass spectrometry. Statistical differences were assessed by analysis of variance and Tukey test (P < .05). Results: Cell viability was moderate after 24 and 48 hours in the presence of MTA Repair HP and NeoMTA Plus, whereas at 48 and 72 hours, Biodentine showed higher rates of cell viability than MTA Repair HP and NeoMTA Plus (P < .001). A cell migration assay revealed adequate cell migration rates for MTA Repair HP and NeoMTA Plus, both similar to the control group rates, meanwhile the highest cell migration rate was observed in the presence of Biodentine (P < .001). Scanning electron microscope studies showed a high degree of cell proliferation and adhesion on Biodentine disks but moderate rates on MTA Repair HP and NeoMTA Plus disks. Energy‐dispersive X‐ray pointed to similar weight percentages of C, O, and Ca in all 3 materials, whereas other elements such as Al, Si, and S were also found. Conclusions: The new pulp‐capping materials MTA Repair HP, NeoMTA Plus, and Biodentine showed a suitable degree of cytocompatibility with hDPSCs, and good cell migration rates, although Biodentine showed higher rates of proliferation time‐dependent. HighlightsResults of this work suggest that hDPSCs show suitable biological response in terms of cell viability, cell proliferation, and cell migration when in contact with extracts from NeoMTA Plus, MTA Repair HP, and Biodentine.NeoMTA Plus and MTA Repair HP exhibited similar cytocompatibility and cell attachment with hDPSCs, whereas Biodentine promotes higher proliferation rates, cell migration, and cell attachment.Further in vitro and in vivo investigations are required to contrast these results and to prove suitable clinical applications of NeoMTA Plus and MTA Repair HP.

Potential of graphene for tissue engineering applications.

Q2 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 To Editor, We read with great interest the article published by Empson et al. The authors suggested the use of nanocarbon particles as graphene to replace damaged connective tissues. In fact, nanocarbons including carbon nanotubes, carbon nanohorns, and graphenes have also shown an enhancement of matrix mechanical properties; their small size and functional capabilities make them attractive therapeutic options as nanofillers for many regenerative medicine applications. In our recent study, we evaluated the effects of the novel biomaterials graphene oxide (GO) and silk fibroin composites on human periodontal ligament mesenchymal stem cells (PDLSCs) phenotype, adhesion, proliferation rate, and viability. Biocompatibility of scaffolds is a prerequisite for generating cell-biomaterial constructs and for their successful clinical application. GO and fibroin-based biomaterials have been previously studied for several tissue engineering based-therapies, but they have never been tested in conjunction with PDLSCs. Morphologic studies by staining of actin cytoskeleton of PDLSCs cultured for different times on GO and fibroin-coated surfaces showed that PDLSCs cultured on fibroin films displayed lower F-actin polymerization, lower cell spreading, and delayed initial adhesion to the biomaterial. By contrast, GO or GO plus fibroin-coated surfaces significantly improved F-actin polymerization, cell spreading, and initial adhesion when compared with fibroin alone. Furthermore, the proliferation rate and phenotype of PDLSCs on GO and fibroin-based biomaterials by MTT colorimetric assays and flow cytometry, respectively, were studied.

Furanocoumarins: Biomolecules of Therapeutic Interest

Abstract Furanocoumarins are a subgroup of phenolic compounds included in the coumarins group. They can be subdivided into two types: linear, generically known as psoralens, among which are included psoralen, xanthotoxin, and bergapten, and angular, generically known as angelicins, including angelicin, sphondin, and pimpinellin. Linear furanocoumarins have been identified in a great variety of plant families, the highest concentrations being found in Apiaceae, Rutaceae, Leguminosae, and Moraceae. Angular furanocoumarins are less widely distributed and are principally confined to the Apiaceae and Leguminosae. Psoralen-containing plants have been used for centuries in a popular medicine to treat vitiligo, a skin disease characterized by lack of pigmentation. Different methods have been used for the extraction, separation, and analysis of furanocoumarins: supercritical fluid extraction, solid-phase extraction, thin-layer chromatography, high-performance liquid chromatography, high-performance liquid chromatography–mass spectrometry, high-speed countercurrent chromatography, gas chromatography, gas chromatography–mass spectrometry, capillary electrophoresis, and pressurized capillary electrochromatography. Furanocoumarins are typical phototoxic compounds that produce photodermatitis in combination with UV light exposure and cytotoxic and mutagenic disorders. At molecular level, furocoumarins bind to cellular constituents such as proteins and lipids, damaging lysosomes, leading to the formation of reactive oxygen species and contributing to the formation of novel antigens by covalent modification of proteins. Furocoumarins are well known for interfering with drug metabolism, in particular with cytochrome P450 (CYP). On the other hand, furanocoumarins possess mutagenic and carcinogenic properties due to their ability to intercalate into dsDNA and create covalent cross-links primarily with thymidine residues. Since the discovery of furanocoumarins and other structurally related biomolecules, extensive research on different aspects of therapeutical interest has been realized due to the exclusive behavior of these compounds when irradiated with UVA light. These properties have made possible the use of these molecules in PUVA (combination therapy of psoralen and UVA radiation) or extracorporeal photopheresis for the treatment not only of many skin diseases such as vitiligo or psoriasis but also of several autoimmune diseases (systemic lupus erythematosus, Crohns disease, type 1 diabetes mellitus, or multiple sclerosis) and for the treatment of cutaneous T-cell lymphoma, solid organ transplant rejection, and graft versus host disease. Importantly, these compounds alone or in combination with other drugs represent promising candidates to develop new therapies or improve the existing ones. This chapter looks at the structures of furanocoumarins, their presence in plants, analytic methods, their pharmacological properties, and their therapeutic uses.