Bone marrow-derived lineage-negative cells accelerate skin regeneration in vivo.

Cell-based therapy is a promising strategy for promoting tissue regeneration when conventional treatments are not effective. ehT choice of the accessible source to obtain a sufficient cell amount and the use of suitable biomaterials to improve the cell delivery efficiency are the main tasks for safe, effective, and reliable application of stem cell therapy. In this study, we have compared the influence of bone marrow-derived Lin¯ cells on skin regeneration after local transplantation with or without type I collagen-based gel in a BALB/c mice full-thickness wound model. Lin¯ cells were isolated using magnetic-associated cell sorting and identified by flow cytometry. Cytokine gene expression was examined using real-time PCR. Our results show that the bone marrow-derived Lin¯ cell population demonstrates the properties to stimulate the skin tissue regeneration. Significant accelerated wound closure was revealed after cell transplantation (P < 0.05). Histological analysis indicated the earliest inhibition of inflammation, accelerated reepithelialization, and evenly distributed skin appendages in the neodermis after Lin¯ cell transplantation with type I collagen gel. eTh significant changes in mRNA levels of cytokines TNF-α, IL-10, TGF-ß, and VEGF after Lin¯ cell transplantation were confirmed by RT-PCR (P < 0.05). eTh ability to positively control the reactions taking place during the wound healing process gives the advantage to the bone marrow Lin¯ cell population to be used as a cell source for therapy.

Exosomes from Human Dental Pulp Stem Cells Suppress Carrageenan-Induced Acute Inflammation in Mice.

The primary goal of this study was to examine the effects of human dental pulp stem cell-derived exosomes on the carrageenan-induced acute inflammation in mice. Exosomes were purified by differential ultracentrifugation from the supernatants of stem cells derived from the dental pulp of human exfoliated deciduous teeth (SHEDs) cultivated in serum-free medium. At 1 h post-carrageenan injection, exosomes derived from supernatants of 2 × 10(6) SHEDs were administered by intraplantar injection to BALB/c mice; 30 mg/kg of prednisolone and phosphate-buffered saline (PBS) were used as positive and negative controls, respectively. Edema was measured at 6, 24, and 48 h after carrageenan injection. For the in vivo imaging experiments, AngioSPARK750, Cat B 750 FAST, and MMPSense 750 FAST were administered into the mouse tail vein 2 h post-carrageenan injection. Fluorescence images were acquired at 6, 24, and 48 h after edema induction by IVIS Spectrum in vivo imaging system. Exosomes significantly reduced the carrageenan-induced edema at all the time points studied (by 39.5, 41.6, and 25.6% at 6, 24, and 48 h after injection, respectively), to similar levels seen with the positive control (prednisolone). In vivo imaging experiments revealed that, both exosomes and prednisolone suppress activities of cathepsin B and matrix metalloproteinases (MMPs) at the site of carrageenan-induced acute inflammation, showing more prominent effects of prednisolone at the early stages, while exosomes exerted their suppressive effects gradually and at later time points. Our study demonstrates for the first time that exosomes derived from human dental pulp stem cells suppress carrageenan-induced acute inflammation in mice.

Impact of diamond nanoparticles on neural cells.

Diamond nanoparticles (DNPs) are very attractive for biomedical applications, particularly for bioimaging. The aim of this study was to evaluate the impact of DNPs on neural cancer cells and thus to assess the possible application of DNPs for these cells imaging. For this purpose, the neuroblastoma SH-SY5Y cell line was chosen. Cells were cultured in medium with different concentrations (15, 50, 100 and 150 µg/ml) of DNPs. After 48 h of incubation, cell metabolic activity was evaluated by the XTT assay. For assessment of cellular metabolic activity, cells were also cultured on differently terminated nanocrystalline diamond (NCD) coatings in medium with 150 µg/ml of DNPs. Cell adhesion and morphology were evaluated by brightfield microscopy. Diamond nanoparticle internalization was determined by confocal microscopy. The obtained results showed that low concentrations (15, 50 and 100 µg/ml) of nanoparticles did not significantly affect the SH-SY5Y cell metabolic activity. However, a higher concentration (150 µg/ml) of DNPs statistically significantly reduced SH-SY5Y cell metabolic activity. After 48 h incubation with 150 µg/ml DNPs, cell metabolic activity was 23% lower than in medium without DNPs on standard tissue culture polystyrene.

Evaluation of cytotoxicity of polypyrrole nanoparticles synthesized by oxidative polymerization.

Polypyrrole (Ppy) is known as biocompatible material, which is used in some diverse biomedical applications and seeming to be a very promising for advanced biotechnological applications. In order to increase our understanding about biocompatibility of Ppy, in this study pure Ppy nanoparticles (Ppy-NPs) of fixed size and morphology were prepared by one-step oxidative polymerization and their cyto-compatibility was evaluated. The impact of different concentration of Ppy nanoparticles on primary mouse embryonic fibroblasts (MEF), mouse hepatoma cell line (MH-22A), and human T lymphocyte Jurkat cell line was investigated. Cell morphology, viability/proliferation after the treatment by Ppy nanoparticles was evaluated. Obtained results showed that Ppy nanoparticles at low concentrations are biocompatible, while at high concentrations they became cytotoxic for Jurkat, MEF and MH-22A cells, and it was found that cytotoxic effect is dose-dependent.

Skin regeneration with bone marrow-derived cell populations.

Bone marrow-derived cells of distinct differentiation level could differently influence the process of skin regeneration. The results of our study revealed that hematopoietic stem cells (HSC) population influenced the repair of injured tissue slower in comparison with lineage negative (lin⁻) cell population containing not only HSC but also cell progenitors of different differentiation levels. Wound healing process was faster in lin⁻) cell suspension treated group, the stage of proliferation was more intensive and increased number of skin appendages occurred. The adaptation of purified HSC at the site of injury was longer and the stages of wound healing took place later. The results obtained show that in further experiments the complex procedure of HSC isolation and purification could be shortened and heavy skin injuries could be successfully treated with the help of lin⁻ cell population.

[Postnatal growth in children born small and appropriate for gestational age during the first years of life]. / Ponatalinis mazu ir atitinkanciu gestacijos amziu vaiku augimas per pirmuosius seserius gyvenimo metus.

UNLABELLED: The aim of the study was to evaluate growth pattern of small- and appropriate-for-gestational-age children and to identify prenatal and postnatal risk factors for short stature and development of components of metabolic syndrome. A total of 109 small- and 239 appropriate-for-gestational-age infants were enrolled in the study. Within 24 hours after birth and at 2, 5, 9, 12, 18, 24 months, and 6 years of age, anthropometric data were recorded for study children. Cord blood samples from study infants were collected, and insulin-like growth factor-1 (IGF), IGF-binding protein-3, and leptin levels were measured. Birth weight and height (P<0.001) and insulin-like growth factor-1, IGF-binding protein-3, and leptin levels (P<0.05) were lower in children born small for gestational age vs. children born appropriate for gestational age. At 2, 5, 12, 18, and 24 months and 6 years of age, children born small for gestational age remained shorter and weighed less (P<0.001). Waist-to-hip ratio, heart rate at 6 years of age and gain in body mass index from birth up to 6 years of age was higher in children born small for gestational age. Height gain during the first year of life was mainly influenced by birth length and target height. Maternal weight before pregnancy and cord leptin levels were the most significant factors influencing postnatal weight gain during the first years of life. CONCLUSIONS: During the first 6 years of life, children born small for gestational age remained shorter and lighter. A greater catch-up in body mass index and tendency towards central pattern of fat distribution during the first years of life might be predisposing factors for the development of long-term metabolic complications in these individuals.