Background: Nanocarriers for antibacterial drugs became hopeful tools against the increasing resistance of bacteria to antibiotics. This work focuses on a comprehensive study of the applicability and therapeutic suitability of dermal carbopol-based hydrogels containing chloramphenicol carried by various nanoparticles (AuNPs and SiNPs). Methods: The different forms of carbopol-based drugs for dermal use were obtained. Five different concentrations of chloramphenicol and two types of nanoparticles (silica and gold) in carbopol-based ointments were tested. The influence of different carbopol formulations with nanocarriers on the rheological properties as well as the release profile of active substances and bacteriostatic activity on five reference strains were determined. Results: The properties of the obtained hydrogels were compared to a commercial formulation, and finally it was possible to obtain a formulation that allowed improved antimicrobial activity over a commercially available detreomycin ointment while reducing the concentration of the antibiotic. Conclusion: The work indicates that it is possible to reduce the concentration of chloramphenicol by four times while maintaining its bacteriostatic activity, which can improve the patient’s safety profile while increasing the effectiveness of the therapy. Graphical

The research was focused on alternative treatment techniques, separating immediate and long-term recon-struction stages. The work involved development of ceramic materials dedicated to reconstruction of the temporomandibular joint area. They were based on alumina (aluminum oxide) and characterized by varying porosities. A broad spectrum of studies was conducted to test the proposed material and determine its suitability for mandibular reconstruction. They compared the effects of substrate properties of ceramic materials in terms of biocompatibility, microbiology and systemic toxicity in in vivo studies. Finally it was concluded that Alumina LithaLox 350D is best suited for jawbone implants.

Yersinia enterocolitica O:3 is mentioned among the most common arthritogenic pathogens. Bacterial components (including lipopolysaccharide (LPS)) may persist in the joint after eradication of infection. Having an adjuvant activity, LPS may enhance production of anticollagen antibodies, involved in the pathogenesis of rheumatoid arthritis. Furthermore, its ability to activate complement contributes to the inflammation. The aim of this work was to investigate whether Yersinia LPS (coinjected with collagen) is associated with arthritis progression or other pathological effects and to elucidate the mechanism of this association. It was demonstrated that murine mannose-binding lectin C (MBL-C) recognizes the inner core heptoses of the Rd1 chemotype LPS of Yersinia. In addition, the Rd1 LPS activates the MBL-associated serine protease 1 (MASP-1) stronger than the S and Ra chemotype LPS and comparable to Klebsiella pneumoniae O:3 LPS. However, in contrast to the latter, Yersinia Rd1 LPS was associated neither with the adjuvancity nor with the enhancement of pathological changes in animal paws/impairment of motility. On the other hand, it seemed to be more hepatotoxic when compared with the other tested endotoxins, while the enlargement of inguinal lymph nodes and drop in hepatic MBL-C expression (at the mRNA level) were independent of LPS chemotype. Our data did not suggest no greater impact Y. enterocolitica O:3 on the development or severity of arthropathy related to anticollagen antibody-induced arthritis in mice, although its interaction with MBL-C and subsequent complement activation may contribute to some adverse effects.

The goal of the work was to develop materials dedicated to spine surgery that minimized the potential for infection originating from the transfer of bacteria during long surgeries. The bacteria form biofilms, causing implant loosening, pain and finally, a risk of paralysis for patients. Our strategy focused both on improvement of antibacterial properties against bacteria adhesion and on wear and corrosion resistance of tools for spine surgery. Further, a ~35% decrease in implant and tool dimensions was expected by introducing ultrahigh-strength titanium alloys for less-invasive surgeries. The tested materials, in the form of thin, multi-layered coatings, showed nanocrystalline microstructures. Performed direct-cytotoxicity studies (including lactate dehydrogenase activity measurement) showed that there was a low probability of adverse effects on surrounding SAOS-2 (Homo sapiens bone osteosarcoma) cells. The microbiological studies (e.g., ISO 22196 contact tests) showed that implanting Ag nanoparticles into Ti/Ti_xN coatings inhibited the growth of E. coli and S. aureus cells and reduced their adhesion to the material surface. These findings suggest that Ag-nanoparticles present in implant coatings may potentially minimize infection risk and lower inherent stress.

Mining and processing phosphate ore are among the essential branches of the economy in some developing countries, including Algeria. Conventional ore beneficiation methods can harm the environment by consuming tremendous amounts of water resources (during washing and flotation), potentially hazardous chemicals, and thermal energy. Mine water contains toxic metals that, when released, interfere with environmental functioning. Therefore, in line with environmental needs, conventional methods should be gradually replaced with safe biotechnological processes. This study aimed to investigate the biosorption and adhesion abilities of native microorganisms isolated from Djebel Onk ore (Algeria). The examined bacterial strains differed in their metal accumulation efficiency. The incubation of phosphate ore with the native strain Bacillus HK4 significantly increased the recovery of Mg and Cd (at pH 7, 8147.00 and 100.89 µg/g⁻¹, respectively). The HK4 strain also revealed better adhesion to the ore particles than the reference strain of Bacillus subtilis. Thus, biosorption could be more effective when using the native HK4 strain, which can remove Cd and/or Mg over a pH 4–10 range. Moreover, concerning the unique adhesion capacity of HK4, the strain can be considered in the design of bioflotation methods, as well as in the development of an eco-friendly method of ore and post-flotation waste beneficiation.

Cardiovascular clamping procedures can cause tissue traumatization, leading to serious adverse events interrupting blood flow and causing life-threatening hemorrhage. The aim of the study is to evaluate the properties of 3D-printed, high-elasticity elastomeric materials—BioMed Flex 50A and 80A (Formlabs Inc., Sommerville, MA, USA)—in terms of their suitability for the fabrication of atraumatic inserts used for surgical clamping instruments. To show the importance of the elaboration of the new atraumatic materials, finite element simulations of blood vessel compression by a surgical tool were validated experimentally with porcine vessels, and histopathology assessed the tissue response. These results confirm that excessive clamping forces can cause vessel wall stratification and rupture. Specimens BioMed Flex 50A and 80A underwent surface, mechanical, and biological testing, including topography, wettability, acoustic microscopy for structural voids, cytotoxicity with human dermal fibroblasts, pro-inflammatory marker analysis, and bacterial biofilm assessment. The results of the testing of the 3D-printed BioMed Flex 50A and 80A materials show good potential for applications in safe atraumatic surgical instruments. Further research may include the possibilities to develop 3D-printed metamaterials with pressure adapting properties.