Hydroxyapatite has been used in medicine for many years as a biomaterial or a cover for other biomaterials in orthopedics and dentistry. This study characterized the physicochemical properties (structure, particle size and morphology, surface properties) of Li+- and Li+/Eu3+-doped nanohydroxyapatite obtained using the wet chemistry method. The potential regenerative properties against neurite damage in cultures of neuron-like cells (SH-SY5Y and PC12 after differentiation) were also studied. The effect of nanohydroxyapatite (nHAp) on the induction of repair processes in cell cultures was assessed in tests of metabolic activity, the level of free oxygen radicals and nitric oxide, and the average length of neurites. The study showed that nanohydroxyapatite influences the increase in mitochondrial activity, which is correlated with the increase in the length of neurites. It has been shown that the doping of nanohydroxyapatite with Eu3+ ions enhances the antioxidant properties of the tested nanohydroxyapatite. These basic studies indicate its potential application in the treatment of neurite damage. These studies should be continued in primary neuronal cultures and then with in vivo models.

Background. Despite the wide range of medical dressings available commercially, there is still a search for better biomaterials for use in the treatment of especially difficult-to-heal wounds. For several years, attention has been paid to the use of substances, compounds, and even whole plants in medicine. Flax is a plant that has been used as a dressing for thousands of years. Therefore, we decided to test flax fibres that had previously been genetically modified as a potential wound dressing. Materials and Methods. In this study, two modified flax fibres and their combinations were tested on cell lines (mice fibroblast, normal human dermal fibroblast, normal human epidermal keratinocytes, human dermal microvascular endothelial cell, epidermal carcinoma cancer cells, monocyte cells). In the tests, fibres of the traditional flax (Nike) were used as a control. Several experiments were performed to assess cell proliferation and viability, the number of apoptotic cells, the cell cycle, genotoxicity, the level of free oxygen radicals, and determination of the number of cells after 48 hours of incubation of cell cultures with the tested flax fibres. Results. The obtained results confirm the positive influence of flax on the used cell lines. Both traditional fibres (Nike) and genetically modified fibres increased the proliferation of fibroblast cells and keratinocytes, reduced the level of free oxygen radicals, and influenced the repair of DNA damage. At the same time, the tested flax fibres did not have a proproliferative effect on the neoplastic cell line. Interestingly, genetic modifications had a stronger impact on the proliferative activity of fibroblasts, keratinocytes, and microvascular endothelium compared to the traditional flax fibre used. Conclusions. In this study, the positive properties of the tested flax fibres on cell lines were proved. In the next stage, it is worth carrying out in vivo tests of tested genetically modified flax fibres.

Feline tooth resorption (odontoclastic resorptive lesion) is a common and important issue in veterinary dentistry. This study aimed to analyse the disease’s severity and correlation with clinical information in the population of feline patients in Poland in the area of Lower Silesia. An analysis of the clinical charts of 174 cats with dental problems, which were diagnosed as tooth resorption, was conducted. The gender and breed had no influence on the disease severity, but the disease progressed with age. The lesions were mostly encountered within the third and fourth maxillary premolars (107, 108, 207, 208) and mandibular molars (309, 409). No direct correlation was found between the presence or severity of the disease and the clinical signs of affected cats. The study shows that feline tooth resorption is a common issue in feline dentistry and should be taken into account in all cases of animals with any signs of oral disease, including gingivitis and/or dental plaque with preserved appetite. A careful intraoral radiographic examination is essential to avoid false negative results in ambiguous cases.