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Background and Objectives: The major cause of vitamin D deficiency is inadequate exposure to sunlight. It is difficult to supplement it with food because sufficient concentrations of vitamin D naturally occur only in a handful of food products. Thereby, deficiency of this vitamin is commonly corrected with oral supplements. Different supplement delivery systems for improved vitamin D stability and bioavailability are proposed. In this study, we compared efficiency of three vitamin D delivery systems: microencapsulated, micellized, and oil-based. Materials and Methods: As a model in this medical testing, laboratory rats were used for the evaluation of bioavailability of different vitamin D vehicles. Animals were divided into three groups: the first one was given microencapsulated vitamin D3, the second—oil-based vitamin D3, and the third—micellized vitamin D3. Test substances were given per os to each animal for 7 days, and vitamin D concentration in a form of 25-hydroxyvitamin D (25(OH)D) in the blood was checked both during the vitamin delivery period and later, up to the 24th day. Results: Comparison of all three tested products showed that the microencapsulated and oil-based vitamin D3 vehicles were the most bioavailable in comparison to micellized vitamin D3. Even more, the effect of the microencapsulated form of vitamin D3 remained constant for the longest period (up to 14 days). Conclusions: The results of this study suggest that the oral vitamin D supplement vehicle has an impact on its bioavailability, thus it is important to take into account how much of the suppled vitamin D will be absorbed. To maximize the full exploit of supplement, the best delivery strategy should be employed. In our study, the microencapsulated form of vitamin D was the most bioavailable.

Topography of the scaffold is one of the most important factors defining the quality of artificial bone. However, the production of precise micro-and nano-structured scaffolds, which is known to enhance osteogenic differentiation, is expensive and time-consuming. Meanwhile, little is known about macro-patterns (larger than cell diameter) effect on cell fate, while this kind of structures would significantly facilitate the manufacturing of artificial skeleton. Therefore, this research is focused on polylactic acid scaffold's macropattern impact on rat's dental pulp stem cells (DPSCs) morphology, proliferation, and osteogenic differentiation. For this study, two types of scaffolds were 3D printed: wavy and porous. Wavy scaffolds consisted of 188 μm wide joined threads, meaning that cells might have been curved on the filament as well as compressed in the groove. Porous scaffolds were designed to avoid groove formation and consisted of 500 μm threads, arranged in the woodpile manner, forming 300 μm diameter pores. We found that both macro-surfaces influenced DPSC morphology compared to control. As a consequence, enhanced DPSC proliferation and increased osteogenic differentiation potential was registered in cells grown on these scaffolds. Finally, our results showed that the construction of an artificial bone did not necessarily require the precise structuring of the scaffold, because both types of macrotopographic PLA scaffolds were sufficient enough to induce spontaneous DPSC osteogenic differentiation. How to cite this article: Alksne M, Simoliunas E, Kalvaityte M, Skliutas E, Rinkunaite I, Gendviliene I, Baltriukiene D, Rutkunas V, Bukelskiene V. 2019. The effect of larger than cell diameter polylactic acid surface patterns on osteogenic differentiation of rat dental pulp stem cells. J Biomed Mater Res Part A 2019:107A:174-186.

Background. Parvovirus B19 (B19V) is a common finding in endomyocardial biopsy specimens from myocarditis and dilated cardiomyopathy patients. However, current understanding of how B19V is contributing to cardiac damage is rather limited due to the lack of appropriate mice models. In this work we demonstrate that immunization of BALB/c mice with the major immunogenic determinant of B19V located in the unique sequence of capsid protein VP1 (VP1u) is an adequate model to study B19V associated heart damage. Methods and Results. We immunized mice in the experimental group with recombinant VP1u; immunization with cardiac myosin derived peptide served as a positive reference and phosphate buffered saline served as negative control. Cardiac function and dimensions were followed echocardiographically 69 days after immunization. Progressive dilatation of left ventricle and decline of ejection fraction were observed in VP1u- and myosin-immunized mice. Histologically, severe cardiac fibrosis and accumulation of heart failure cells in lungs were observed 69 days after immunization. Transcriptomic profiling revealed ongoing cardiac remodeling and immune process in VP1u- and myosin-immunized mice. Conclusions. Immunization of BALB/c mice with VP1u induces dilated cardiomyopathy in BALB/c mice and it could be used as a model to study clinically relevant B19V associated cardiac damage.