We analyzed the influence of inflammatory macrophages on the osteogenic process in subcutaneous implants composed of mineral bone substitute. Thioglycollate-elicited peritoneal macrophages (TEPMs) were characterized as inflammatory. This was confirmed microscopically by the nitroblue tetrazolium (NBT) test and the production of tumor necrosis factor ? (TNF-?). The implants (M-type) were made of mineral bone substitute (Bio-Oss?) mixed with TEPMs and blood clot. Implants without macrophages served as the control (C-type). Subcutaneous implantation in the interscapular area was performed on BALB/c mice. Implants were extracted after 2 and 8 weeks. In M-type implants, phagocytosis and angiogenesis were more pronounced, and osteoblast-like cells aligned onto granules of implanted material and osteoid structures can be seen. The observed higher osteocalcin and lower osteopontin immunoexpression in M-type implants when compared to the control after 8 weeks suggest a more advanced osteogenic process. Our results indicate that the presence of inflammatory macrophages in the composition of an implant may have a beneficial effect on the osteogenic process.

Biphasic calcium phosphate (BCP) materials are widely employed as bone substitute materials due to their resorption/degradation properties. Inflammation after implantation of such materials represents a prerequisite for bone tissue repair and regeneration but can be also problematic if it is not only transient and if it is followed by fibrosis and scarring. Here, we modified BCP covalently with hyaluronan (HA) and heparin (Hep), glycosaminoglycans that possess anti‐inflammatory properties. Beside the characterization of particle surface properties, the focus was on in vivo tissue response after subcutaneous implantation in mice. Histological analysis revealed a decrease in signs of inflammatory response to BCP when modified with either HA or Hep. Reduced vascularization after 30 days was noticed when BCP was modified with either HA or Hep with greater cellularity in all examined time points. Compared to plain BCP, expression of endothelial‐related genes Flt1 and Vcam1 was higher in BCP‐HA and BCP‐Hep group at day 30. Expression of osteogenesis‐related genes Sp7 and Bglap after 30 days was the highest in BCP group, followed by BCP‐Hep, while the lowest expression was in BCP‐HA group which correlates with collagen amount. Hence, coating of BCP particles with HA seems to suppress inflammatory response together with formation of new bone‐like tissue, while the presence of Hep delays the onset of inflammatory response but permits osteogenesis in this subcutaneous bone‐forming model. Transferring the results of this study to other coated materials intended for biomedical application may also pave the way to reduction of inflammation after their implantation.

Osteoclasts, as the only cells capable of resorbing bone, play a significant role in all processes that take place at the level of bone tissue and are involved in the development of the skeleton, maintenance of its integrity, repair, and regeneration of bones. Therefore, it is not surprising that even small deviations from their normal functioning result in diseases that not only affect skeletal system but also the entire organism. There are a number of rare genetic bone diseases associated with mutations in osteoclast genes that govern their differentiation and function. Specifically, they are known as osteoclast-related diseases, and their main hallmark is either decreased or increased bone resorption. To understand the impact of osteoclast gene mutations on the course of these diseases, it is also necessary to know the cellular and molecular mechanisms underlying osteoclast development and function. Moreover, identification of specific gene mutations as potential therapeutic targets would be an important step in creating personalized gene therapies in the future.

The aim of this study was to compare the stability and texture of three zinc oxide suspensions with different additives. Suspension 1 was made as official magistral formulation Suspensio album 7.5% from Formulae magistrales 2008. Suspension 2 was prepared when 1% carbomer gel was added to suspension 1 and suspension 3 was prepared when polysorbate 20 was added to suspension 2. After stability tests, texture analysis was performed on all suspensions. Following parameters were measured: hardness cycle 1, hardness cycle 2, cohesiveness, adhesiveness, resilience and springiness. The study showed that suspension 3 had the lowest value of hardness, and therefore the best spreadability. Also, suspension 3 was the least sticky of all three, since it was characterized with the lowest adhesiveness. Further, suspension 3 was the most cohesive and is predicted to withstand the stress during packing and use longer than others. On the other hand, the highest values of resilience and springiness were detected for suspension 1, while the lowest was related to suspension 2. Therefore, the best textural characteristics were assigned to suspension 3. This result is in accordance with the results of performed stability tests. The results of our study offer insight into potential improvements of the current magistral formulation Suspensio album 7.5%.