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Věra Hedvičáková,1 Radmila Žižková,1,2 Matěj Buzgo,1,3 Lucie ViÅ¡tejnová,4 Pavel Klein,4,5 Maria Hovořáková,6 Martin BartoÅ¡,7,8 Klára Steklíková,6 Jitka Luňáčková,7 Eva Å ebová,1 Iveta Paurová,4 Miroslava Rysová,9 Eva Filová,1 Michala Rampichová1 1Department of Tissue Engineering, Institute of Experimental Medicine, the Czech Academy of Sciences, Prague, Czech Republic; 2Department of Chemistry, Faculty of Science, Humanities and Education, Technical University of Liberec, Liberec, Czech Republic; 3BIOFABICS Lda, Porto, Portugal; 4Biomedical Center, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic; 5Department of Pathological Physiology, Faculty of Medicine in Pilsen, Charles University, Pilsen, Czech Republic; 6Institute of Histology and Embryology, First Faculty of Medicine, Charles University, Prague, Czech Republic; 7Institute of Dental Medicine, First Faculty of Medicine and General University Hospital, Prague, Czech Republic; 8Institute of Anatomy, First Faculty of Medicine, Charles University, Prague, Czech Republic; 9Department of Applied Biology, Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Liberec, Czech RepublicCorrespondence: Michala Rampichová, Department of Tissue engineering, Institute of Experimental Medicine, the Czech Academy of Sciences, Videnska 1083, Prague, 14220, Czech Republic, Tel +420 241 062 692, Email michala.rampichova@iem.cas.czPurpose: Osteoporosis is a severe health problem with social and economic impacts on society. The standard treatment consists of the systemic administration of drugs such as bisphosphonates, with alendronate (ALN) being one of the most common. Nevertheless, complications of systemic administration occur with this drug. Therefore, it is necessary to develop new strategies, such as local administration.Methods: In this study, emulsion/dispersion scaffolds based on W/O emulsion of PCL and PF68 with ALN, containing hydroxyapatite (HA) nanoparticles as the dispersion phase were prepared using electrospinning. Scaffolds with different release kinetics were tested in vitro on the co-cultures of osteoblasts and osteoclast-like cells, isolated from adult osteoporotic and control rats. Cell viability, proliferation, ALP, TRAP and CA II activity were examined. A scaffold with a gradual release of ALN was tested in vivo in the bone defects of osteoporotic and control rats.Results: The release kinetics were dependent on the scaffold composition and the used system of the poloxamers. The ALN was released from the scaffolds for more than 22 days. The behavior of cells cultured in vitro on scaffolds with different release kinetics was comparable. The difference was evident between cell co-cultures isolated from osteoporotic and control animals. The PCL/HA scaffold show slow degradation in vivo and residual scaffold limited new bone formation inside the defects. Nevertheless, the released ALN supported bone formation in the areas surrounding the residual scaffold. Interestingly, a positive effect of systemic administration of ALN was not proved.Conclusion: The prepared scaffolds enabled tunable control release of ALN. The effect of ALN was proved in vitro and in in vivo study supported peri-implant bone formation.Keywords: alendronate, co-culture, fibrous scaffold, osteoporosis, drug delivery system

Cadmium has no known physiological function in the body, however, its adverse effects are associated with cancer and many types of organ system damage. Although much has been shown about Cd toxicity, the underlying mechanisms of its responses to the organism remain unclear. In this study, the role of Tor1, a catalytic subunit of the target of rapamycin complex 2 (TORC2), in Cd-mediated effects on cell proliferation, the antioxidant system, morphology, and ionome balance was investigated in the eukaryotic model organism Schizosaccharomyces pombe. Surprisingly, spectrophotometric and biochemical analyses revealed that the growth rate conditions and antioxidant defense mechanisms are considerably better in cells lacking the Tor1 signaling. The malondialdehyde (MDA) content of Tor1-deficient cells upon Cd treatment represents approximately half of the wild-type content. The microscopic determination of the cell morphological parameters indicates the role for Tor1 in cell shape maintenance. The ion content, determined by inductively coupled plasma optical emission spectroscopy (ICP-OES), showed that the Cd uptake potency was markedly lower in Tor1-depleted compared to wild-type cells. Conclusively, we show that the cadmium-mediated cell impairments in the fission yeast significantly depend on the Tor1 signaling. Additionally, the data presented here suggest the yet-undefined role of Tor1 in the transport of ions.