Non-rigid calcium phosphate cement containing hydrogel microbeads and absorbable fibres seeded with umbilical cord stem cells for bone engineering

The liver is a vital organ for life and the only internal organ that is capable of natural regeneration. Although the liver has high regeneration capacity, excessive hepatocyte death can lead to liver failure. Various factors can lead to liver damage including drug abuse, some natural products, alcohol, hepatitis, and autoimmunity. Some models for studying liver injury are APAP-based model, Fas ligand (FasL), D-galactosamine/endotoxin (Gal/ET), Concanavalin A, and carbon tetrachloride-based models. The regeneration of the liver can be carried out using umbilical cord blood stem cells which have various advantages over other stem cell types used in liver transplantation. UCB-derived stem cells lack tumorigenicity, have karyotype stability and high immunomodulatory, low risk of graft versus host disease (GVHD), low risk of transmitting somatic mutations or viral infections, and low immunogenicity. They are readily available and their collection is safe and painless. This review focuses on recent development and modern trends in the use of umbilical cord stem cells for the regeneration of liver fibrosis.

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Microbial stresses on human umbilical cord stem cells

Current Stem Cell Research & Therapy ◽

10.2174/1574888x15666200309144334 ◽

2020 ◽

Vol 15 ◽

Author(s):

Didem Kart ◽

Betül Çelebi-Saltik

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Umbilical Cord ◽

Bacterial Load ◽

Early Period ◽

Stress Factors ◽

Human Umbilical Cord ◽

Antibacterial Effects ◽

Hematopoietic Stem ◽

Umbilical Cord Stem Cells

: Umbilical cord and cord blood are acceptable as attractive sources of mesenchymal and hematopoietic stem cells, since their collection is non-invasive, painless, and does not evoke the ethical concerns. Microorganism-stem cell interaction plays an important role in stem cell self-renewal, differentiation, secretion profile and death. In the literature, few researchers are examining the relationship between pathogenic and commensal bacteria with umbilical cord-derived Mesenchymal Stem Cells (MSCs). These relationships vary depending on the bacterial load and the presence of the immune cell in the environment. Several bacterial pathogens act in the regenerative capacity of MSCs by changing their phenotype, development and viability due to several stress factors that are created by a microorganism such as hypoxia, oxidative stress, etc. On the other hand, the anti-inflammatory and antibacterial effects of MSCs were shown and these phenomena increased when the number of bacteria was high but decreased in the presence of low amounts of bacteria. The antibacterial effects of MSCs increased in the early period of infection, while their effects were decreased in the late period with high inflammatory response and bacterial load. In this review, we discussed the microbial stresses on human umbilical cord stem cells.

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Enhanced Osteogenesis of Dental Pulp Stem Cells In Vitro Induced by Chitosan–PEG-Incorporated Calcium Phosphate Cement

Polymers ◽

10.3390/polym13142252 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2252

Author(s):

Jae Eun Kim ◽

Sangbae Park ◽

Woong-Sup Lee ◽

Jinsub Han ◽

Jae Woon Lim ◽

...

Keyword(s):

Stem Cells ◽

Calcium Phosphate ◽

Zeta Potential ◽

Mechanical Strength ◽

Calcium Phosphate Cement ◽

Dental Pulp ◽

Dental Pulp Stem Cells ◽

Ion Trapping ◽

Alizarin Red

The use of bone graft materials is required for the treatment of bone defects damaged beyond the critical defect; therefore, injectable calcium phosphate cement (CPC) is actively used after surgery. The application of various polymers to improve injectability, mechanical strength, and biological function of injection-type CPC is encouraged. We previously developed a chitosan–PEG conjugate (CS/PEG) by a sulfur (VI) fluoride exchange reaction, and the resulting chitosan derivative showed high solubility at a neutral pH. We have demonstrated the CPC incorporated with a poly (ethylene glycol) (PEG)-grafted chitosan (CS/PEG) and developed CS/PEG CPC. The characterization of CS/PEG CPC was conducted using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The initial properties of CS/PEG CPCs, such as the pH, porosity, mechanical strength, zeta potential, and in vitro biocompatibility using the WST-1 assay, were also investigated. Moreover, osteocompatibility of CS/PEG CPCs was carried out via Alizarin Red S staining, immunocytochemistry, and Western blot analysis. CS/PEG CPC has enhanced mechanical strength compared to CPC, and the cohesion test also demonstrated in vivo stability. Furthermore, we determined whether CS/PEG CPC is a suitable candidate for promoting the osteogenic ability of Dental Pulp Stem Cells (DPSC). The elution of CS/PEG CPC entraps more calcium ion than CPC, as confirmed through the zeta potential test. Accordingly, the ion trapping effect of CS/PEG is considered to have played a role in promoting osteogenic differentiation of DPSCs. The results strongly suggested that CS/PEG could be used as suitable additives for improving osteogenic induction of bone substitute materials.

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