Background: The present research addresses the issue of skin aging and corresponding skin treatment individualization. Particular research question was on the development of a simplified criterion supporting patientspecific decisions about the necessity and intensity of skin treatment. Basing on published results and a wide pool of our own experimental data, a hypothesis is formulated that a difference between biologic and chronologic age can be used as a powerful indicator of skin aging. Methods: In the present paper, we report the results of studies with 80 volunteers between 15 and 65 years of age linking skin cell profile parameters to biologic and chronologic age. Biologic age was calculated using the empirical expressions based on the forced vital lung capacity, systolic blood pressure, urea concentration, and blood cholesterol level. Epidermis and derma cellular structures were studied using skin biopsy samples taken from the gluteal region. Results: The present study supports the conclusion that biologic and chronologic age difference is changing in the progress of life. Our studies are showing that time point when calculated biologic age becomes equal to the chronologic one reflecting the onset of specific changes in the age dependencies of experimentally measured skin cell profile parameters. Thus, it is feasible that a difference between chronologic and individually assessed biologic age indeed reflects the process of skin aging. Conclusions: With all reservations to the relatively small number of study participants, it seems feasible that a difference between biologic and chronologic age can be used as an indicator of skin aging. Additional research linking blood immune profile and skin topography to the difference of biologic and chronologic age (reported in the following paper) provides further support for the formulated hypotheses. So, a difference between calculated biologic age and chronologic age can be used as an individualized criterion supporting decisions on skin treatment strategies. Further research involving larger numbers of participants aimed at optimizing the expressions for calculating biologic age could lead to reliable and easily available express criterion supporting the decision for the individualized skin treatment.

The restoration of damaged tissues in periodontal diseases is not only a medical problem, but also a social one. Periodontal diseases often entail the loss of a large number of teeth (more than with any other disease of the dentition), as a result, a violation of the act of chewing and speech, a negative effect on the general condition of the body and, as a result, a decrease in the quality of human life. Purpose of the study: to study the regenerative activity of a lyophilized extract of a chicken embryo of various concentrations in the composition of hyaluronic acid in relation to the culture of PDLSC cells in an in vitro experiment. Comparison groups: A solution of 1% unmodified hyaluronic acid containing lyophilized chicken embryo extract in three concentrations: 300 μg/ml, 150 μg/ml, 75 μg/ml. As a control, 1% solution of unmodified hyaluronic acid. Hyaluronic acid is a natural substance that is an important component of the extracellular matrix as a mineralized and non-mineralized tissue. Its use attracts the attention of specialists as an object capable of acquiring new properties with its various modifications. In our laboratory studies, stem cells from a culture of human periodontal disease were used. Periodontitis stem cells (PDLSC periodontal ligament) were discovered in 2004. Cell adhesion and tissue penetration were investigated by impedimetry. Analysis to assess cell viability was carried out using a solution containing a water-soluble tetrazolium salt. Differentiation of osteogenic direction without induction was measured three weeks after dilution of stem cells in traditional culture medium. Staining was carried out according to the Koss method. To assess mineralization, cells were stained with alizarin red, followed by assessment of calcium deposition in them. It was found that the resulting PDLSC cell population during the experiment was heterogeneous and showed healthy fibroblast morphology in all three study groups. Lyophilized extract of chicken embryo as part of a preparation based on hyaluronic acid does not significantly affect the survival and proliferation of PDLSC cells, however, at high concentrations (150 μg/ml and 300 μg/ml) it induces osteogenic activity of cells, increases mineralization without causing calcium deposition, which indicates regenerative activity. Osteogenic transdifferentiation is an attractive way to create cells of osteogenic cellular origin. The results of our study show that they can be used to model bone diseases.

Background: Present research addresses the issue of skin aging and corresponding skin treatment individualization. Particular research question was on the developing of simplified criterion supporting patient-specific decision on the necessity and intensity of skin treatment. Basing on the published results and a wide pool of experimental data, we have formulated a hypothesis that a difference between biologic and chronologic age can be used as an express criterion of skin aging. Methods: In present paper, we report the results of studies with 80 volunteers between 15 and 65 years of age, linking parameters reflecting immune state, skin state, and topography to the difference between biologic and chronologic age. Facial skin topography, skin moisture, sebum level, and skin elasticity were studied using commercial devices. Blood immunology studies were performed using venous blood samples. Correlations between all measured parameters and age difference were calculated. Also, cross correlations between skin cell profile and blood immune profile parameters, and skin roughness parameters were calculated. Results: Age dependencies of the blood immunological parameters on the biologic and chronologic age difference are less pronounced as compared to the changes in skin cell profile parameters. However, the changes in the tendencies when biologic age becomes equal to chronologic one are visible for all studied parameters. All measured skin roughness parameters show correlations with age difference, but average skin roughness and depth of the deepest profile valley have the largest correlation coefficient values. Many of the measured skin cell profile and blood immunology parameters show strong correlations with average skin roughness and deepest profile valley, with some of the coefficients exceeding 0.5-0.6. Conclusions: Basing on own experiments and published research results, it is possible to suggest using the difference between calculated biologic age and chronologic age as an individualized criterion supporting decisions on skin treatment strategy. Further research involving larger numbers of participants and aiming on optimizing the expressions for calculating biologic age could lead to reliable and easily available express criterion supporting the decision making for an individualized skin treatment.

We suggest a novel approach for searching natural compounds with anti-aging and rejuvenation potential using cell cultures, with a high potential for the further in vivo applications. The present paper discusses ways of defining age for cell populations with large numbers of cells and suggests a method of assessing how young or old a cell population is based on a cell age profile approach. This approach uses experimental distributions of the cells over the cell cycle stages, acquired using flow cytometry. This paper discusses how such a profile should evolve under homeostatic maintenance of cell numbers in the proliferation niches. We describe promising results from experiments on a commercial substance claiming rejuvenating and anti-aging activity acting upon the cultures of human mononuclear cells and dermal fibroblasts. The chosen substance promotes a shift towards larger proportion of cells in synthesis and proliferation stages, and increases cell culture longevity. Further, we describe promising in vivo testing results of a selected food supplement. Based on the described concept of cell age profile and available test results, a strategy to search for natural compounds with regenerative, anti-aging and rejuvenation potential is suggested and proposed for wider and thorough testing. Proposed methodology of age assessment is rather generic and can be used for quantitative assessment of the anti-aging and rejuvenation potential of different interventions. Further research aimed at the tests of the suggested strategy using more substances and different interventions, and the thorough studies of molecular mechanisms related to the action of the substance used for testing the suggested search methodology, are needed.