The aim of this work was to study effect of the type of silica nanoparticles on the properties of nanocomposites for application in the guided bone regeneration (GBR). Two types of nanometric silica particles with different size, morphology and specific surface area (SSA) i.e., high specific surface silica (hss-SiO₂) and low specific surface silica (lss-SiO₂), were used as nano-fillers for a resorbable polymer matrix: poly(L-lactide-co-D,L-lactide), called PLDLA. It was shown that higher surface specific area and morphology (including pore size distribution) recorded for hss-SiO₂ influences chemical activity of the nanoparticle; in addition, hydroxyl groups appeared on the surface. The nanoparticle with 10 times lower specific surface area (lss-SiO₂) characterized lower chemical action. In addition, a lack of hydroxyl groups on the surface obstructed apatite nucleation (reduced zeta potential in comparison to hss-SiO₂), where an apatite layer appeared already after 48 h of incubation in the simulated body fluid (SBF), and no significant changes in crystallinity of PLDLA/lss-SiO₂ nanocomposite material in comparison to neat PLDLA foil were observed. The presence and type of inorganic particles in the PLDLA matrix influenced various physicochemical properties such as the wettability, and the roughness parameter note for PLDLA/lss-SiO₂ increased. The results of biological investigation show that the bioactive nanocomposites with hss-SiO₂ may stimulate osteoblast and fibroblast cells’proliferation and secretion of collagen type I. Additionally, both nanocomposites with the nanometric silica inducted differentiation of mesenchymal cells into osteoblasts at a proliferation stage in in vitro conditions. A higher concentration of alkaline phosphatase (ALP) was observed on the material modified with hss-SiO₂ silica.

The aim of the work was to examine the possibility of using modified halloysite nanotubes as a gentamicin carrier and to determine the usefulness of the modification in terms of the effect on the amount of the drug attached, its release time, but also on the biocidal properties of the carriers. In order to fully examine the halloysite in terms of the possibility of gentamicin incorporating, a number of modifications of the native halloysite were carried out prior to gentamicin intercalation with the use of sodium alkali, sulfuric and phosphoric acids, curcumin and the process of delamination of nanotubes (expanded halloysite) with ammonium persulfate in sulfuric acid. Gentamicin was added to unmodified and modified halloysite in an amount corresponding to the cation exchange capacity of pure halloysite from the Polish Dunino deposit, which was the reference sample for all modified carriers. The obtained materials were tested to determine the effect of surface modification and their interaction with the introduced antibiotic on the biological activity of the carrier, kinetics of drug release, as well as on the antibacterial activity against Escherichia coli Gram-negative bacteria (reference strain). For all materials, structural changes were examined using infrared spectroscopy (FTIR) and X-ray diffraction (XRD); thermal differential scanning calorimetry with thermogravimetric analysis (DSC/TG) was performed as well. The samples were also observed for morphological changes after modification and drug activation by transmission electron microscopy (TEM). The conducted tests clearly show that all samples of halloysite intercalated with gentamicin showed high antibacterial activity, with the highest antibacterial activity for the sample modified with sodium hydroxide and intercalated with the drug. It was found that the type of halloysite surface modification has a significant effect on the amount of gentamicin intercalated and then released into the surrounding environment but does not significantly affect its ability to further influence drug release over time. The highest amount of drug released among all intercalated samples was recorded for halloysite modified with ammonium persulfate (real loading efficiency above 11%), for which high antibacterial activity was found after surface modification, before drug intercalation. It is also worth noting that intrinsic antibacterial activity was found for non-drug-intercalated materials after surface functionalization with phosphoric acid (V) and ammonium persulfate in the presence of sulfuric acid (V).

This paper aims to study the suitability of partial replacement of lime by waste originating from the cleaning of flue gases from the combustion of industrial wastes in the production of autoclaved aerated concrete (AAC). The compressive strength, bulk density, pore structure, phase composition, and microstructure of hydration products of the AAC were analyzed. According to the results, the addition of the waste can effectively enhance the mechanical properties of AAC due to the differences in morphology of hydration product—1.1 nm tobermorite and related dense microstructure. The pore size distribution was significantly influenced by waste addition, which was one of the main reasons for the increase in thermal conductivity. The XRD and SEM results showed that foreign ions introduced with the wastes affect the synthesis of 1.1 nm tobermorite. Moreover, it was shown that waste containing a high content of CaO can be used as lime replacement, which allows reducing CO₂ emissions during the AAC production process.

The aim of the study was to develop hybrid nanomaterials based on monodisperse silica spheres as carriers for silver nanoparticles (AgNPs) or bismuth nanoparticles (BiNPs) and to evaluate their antimicrobial properties. Silica spheres were synthesized using a modified Stöber method, either unmodified or functionalized with (3-aminopropyl)triethoxysilane (APTES), prior to AgNP or BiNP deposition. The materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP-OES), and zeta potential measurements, while antimicrobial activity was assessed by microdilution against Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Enterococcus faecium) and Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), with Helicobacter pylori as a clinical model. The results show that both SiO₂-AgNP and SiO₂-BiNP composites completely inhibited H. pylori and showed high activity against other pathogens, although P. aeruginosa remained less susceptible. Functionalization of AgNP-coated samples with APTES promoted uniform distribution of AgNPs, with the minimum bactericidal concentration (MBC) to minimum inhibitory concentration (MIC) ratios ranging from 1 to 4, confirming a bactericidal rather than bacteriostatic effect. In contrast, BiNP-coated samples without APTES exhibited lower MIC values from 74 to 595 μg mL⁻¹, consistent with increased Bi³⁺ release from amorphous phases. This indicates the antimicrobial potential, highlighting the role of surface functionalization in regulating ion release and biological performance, and suggesting applications in the biomedical and food industries.