Design, clinical applications and post-surgical assessment of bioresorbable 3D-printed craniofacial composite implants.

This study details the design, fabrication, clinical trials' evaluation, and analysis after the clinical application of 3D-printed bone reconstruction implants made of nHAp@PLDLLA [nanohydroxyapatite@poly(L-lactide-co-D,L-lactide)] biomaterial. The 3D-printed formulations have been tested as bone reconstruction Cranioimplants in 3 different medical cases, including frontal lobe, mandibular bone, and cleft palate reconstructions. Replacing one of the implants after 6 months provided a unique opportunity to evaluate the post-surgical implant obtained from a human patient. This allowed us to quantify physicochemical changes and develop a spatial map of osseointegration and material degradation kinetics as a function of specific locations. To the best of our knowledge, hydrolytic degradation and variability in the physicochemical and mechanical properties of the biomimetic, 3D-printed implants have not been quantified in the literature after permanent placement in the human body. Such analysis has revealed the constantly changing properties of the implant, which should be considered to optimize the design of patient-specific bone substitutes. Moreover, it has been proven that the obtained composition can produce biomimetic, bioresorbable and bone-forming alloplastic substitutes tailored to each patient, allowing for shorter surgery times and faster patient recovery than currently available methods.

Multi-element analysis of metals in human pathological and unchanged thyroid glands - pilot study.

Disturbances in the homeostasis of the elemental composition of thyroid tissue may have serious metabolic and health consequences. It is believed that the accumulation of some metals or the deficiency of others may even cause lethal tumours. Due to the fact that metallomics most often uses human serum to analyse macro and microelements as well as trace elements, it was decided to use material that is more difficult to obtain, but also adds credibility to the research - thyroid tissue samples biopsy. The experiments were conducted on 17 patients diagnosed with: nodular (10) and colloidal goitre (2), chronic thyroiditis (2), follicular adenoma (2) and papillary carcinoma (1). They were recruited by collecting a tumour fragment, control fragment and serum from each of them. The content of Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Zn was examined using ICP-OES (Inductively Coupled Plasma - Optical Emission Spectrometers). Simultaneously, biochemical methods were used to determine the markers of inflammation, glycation and peroxidation: malondialdehyde, pentosidine, reactive free amine content, compounds with thiol groups and galectin 3 in the sera of the examined patients. Three statistically significant correlations were identified: Ca-Mg and Cu-Zn in control tissues (p < 0.05) and Cr-Mn in pathological tissues (p < 0.05). A comparison of individual groups of patients shows that there are some potentail tendencies to increase or decrease in the concentration of certain elements or markers of inflammation and glycation, therefore we discuss potential relationships between a given parameter and a thyroid disorder. The pilot study is an introduction to a deeper analysis aimed at tracing the pathomechanism of the development of thyroid diseases, so that the risk of developing these diseases can be effectively minimized.

The Study of Nanosized Silicate-Substituted Hydroxyapatites Co-Doped with Sr2+ and Zn2+ Ions Related to Their Influence on Biological Activities.

Nanosized silicate-substituted hydroxyapatites, characterized by the general formula Ca9.8-x-nSrnZnx(PO4)6-y(SiO4)y(OH)2 (where: n = 0.2 [mol%]; x = 0.5-3.5 [mol%]; y = 4-5 [mol%]), co-doped with Zn2+ and Sr2+ ions, were synthesized with the help of a microwave-assisted hydrothermal technique. The structural properties were determined using XRD (X-ray powder diffraction) and Fourier-transformed infrared spectroscopy (FT-IR). The morphology, size and shape of biomaterials were detected using scanning electron microscopy techniques (SEM). The reference strains of Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa were used to assess bacterial survivability and the impact on biofilm formation in the presence of nanosilicate-substituted strontium-hydroxyapatites. Safety evaluation was also performed using the standard cytotoxicity test (MTT) and hemolysis assay. Moreover, the mutagenic potential of the materials was assessed (Ames test). The obtained results suggest the dose-dependent antibacterial activity of nanomaterials, especially observed for samples doped with 3.5 mol% Zn2+ ions. Moreover, the modification with five SiO4 groups enhanced the antibacterial effect; however, a rise in the toxicity was observed as well. No harmful activity was detected in the hemolysis assay as well as in the mutagenic assay (Ames test).

Culture Media Composition Influences the Antibacterial Effect of Silver, Cupric, and Zinc Ions against Pseudomonas aeruginosa.

Different metals, such as silver (Ag), copper (Cu), and zinc (Zn), have been broadly investigated as metals and cations used both in medicine and everyday life due to their broad spectrum of antibacterial activity. Although the antibacterial action of those metals and their ions is well known and studied, the main problem remains in the standardization of experimental procedures to determine the antimicrobial activity as bacteriological media composition might significantly influence the outcome. The presented study aimed to evaluate the appropriability of different culture media (four nutritionally rich and four minimal) in the testing of the antibacterial activity of Ag+, Cu2+, and Zn2+ ions against Pseudomonas aeruginosa. Our investigation revealed the influence of medium ingredients and the presence of phosphates, which significantly reduced the activity of tested metal ions. Moreover, the precipitate formation and decrease in pH in the minimal media were additionally observed. It was assumed that the most favorable medium for metal ion activity testing was Luria-Bertani complex medium and MOPS minimal medium.

Investigation of topography effect on antibacterial properties and biocompatibility of nanohydroxyapatites activated with zinc and copper ions: In vitro study of colloids, hydrogel scaffolds and pellets.

In the present work, nanohydroxyapatites (nHAp) doped with copper and/or zinc ions were investigated for the assessment of its antibacterial activity and biocompatibility. Three forms of material with diverse surfaces were tested: nanopowder in colloidal suspension, galactose hydrogel (3,6-Anhydro-α-l-Galacto-ß-d-Galactan) scaffold and pellet. The structural and morphological properties of the obtained biomaterials were comprehensively determined by using: XRPD, FT-IR, SEM-EDS, AAS, XPS and EPR techniques. The antimicrobial active ions, mostly Cu2+, were successfully released from the apatite structure despite the material being suspended in the porous galactose hydrogel matrix. The colloidal solutions of nanohydroxyapatites on bacterial viability revealed moderate activity of Cu2+-doped materials against Escherichia coli strain and significant activity against Pseudomonas aeruginosa strain. The comparative study of bacterial attachment to the hydrogel and pellet surface indicated that hydrogels were more prone to be colonized by both tested strains. Moreover, an additive of the Cu2+ ion modified bacterial attachment and biofilms forming on nHAp:Cu2+ and nHAp:Cu2+-Zn2+ materials. In the case of hydrogels, the biofilms were scattered while these forming on other materials were more clumped. The cytotoxicity evaluation of tested biomaterials showed biocompatible properties of both nanomaterial colloidal solutions as well as galactose hydrogel eluates toward normal mouse osteoblast cell lines (7F2) and human chondrocytes (TC28A2) and osteosarcoma cell line (U2OS). The biocompatibility of tested materials was additionally confirmed by conducting a hemolysis assay which showed full hemocompatibility of nanopowder colloidal solutions and galactose-based materials. Furthermore, unaltered red blood cell morphology was visible after a short and long time of incubation with the obtained biomaterials by using confocal laser scanning microscopy (CLSM). The comparison research provided data of 7F2, TC28 and U2OS cell attachment to the galactose hydrogel surface.

Multifunctionality of Nanosized Calcium Apatite Dual-Doped with Li+/Eu3+ Ions Related to Cell Culture Studies and Cytotoxicity Evaluation In Vitro.

Li+/Eu3+ dual-doped calcium apatite analogues were fabricated using a microwave stimulated hydrothermal technique. XRPD, FT-IR, micro-Raman spectroscopy, TEM and SAED measurements indicated that obtained apatites are single-phased, crystallize with a hexagonal structure, have similar morphology and nanometric size as well as show red luminescence. Lithium effectively modifies the local symmetry of optical active sites and, thus, affects the emission efficiency. Moreover, the hydrodynamic size and surface charge of the nanoparticles have been extensively studied. The protein adsorption (lysozyme, LSZ; bovine serum albumin, BSA) on the nanoparticle surface depended on the type of cationic dopant (Li+, Eu3+) and anionic group (OH-, Cl-, F-) of the apatite matrix. Interaction with LSZ resulted in a positive zeta potential, and the nanoparticles had the lowest hydrodynamic size in this protein medium. The cytotoxicity assessment was carried out on the human osteosarcoma cell line (U2OS), murine macrophages (J774.E), as well as human red blood cells (RBCs). The studied apatites were not cytotoxic to RBCs and J774.E cells; however, at higher concentrations of nanoparticles, cytotoxicity was observed against the U2OS cell line. No antimicrobial activity was detected against Gram-negative bacteria with one exception for P. aeruginosa treated with Li+-doped fluorapatite.

New Approach to Antifungal Activity of Fluconazole Incorporated into the Porous 6-Anhydro-α-l-Galacto-ß-d-Galactan Structures Modified with Nanohydroxyapatite for Chronic-Wound Treatments-In Vitro Evaluation.

New fluconazole-loaded, 6-Anhydro-α-l-Galacto-ß-d-Galactan hydrogels incorporated with nanohydroxyapatite were prepared and their physicochemical features (XRD, X-ray Diffraction; SEM-EDS, Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy; ATR-FTIR, Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy), fluconazole release profiles and enzymatic degradation were determined. Antifungal activity of pure fluconazole was tested using Candida species (C. albicans, C. tropicalis, C. glabarata), Cryptococcus species (C. neoformans, C. gatti) and Rhodotorula species (R. mucilaginosa, R. rubra) reference strains and clinical isolates. Standard microdilution method was applied, and fluconazole concentrations of 2-250 µg/mL were tested. Moreover, biofilm production ability of tested isolates was tested on the polystyrene surface at 28 and 37 ± 0.5 °C and measured after crystal violet staining. Strains with the highest biofilm production ability were chosen for further analysis. Confocal microscopy photographs were taken after live/dead staining of fungal suspensions incubated with tested hydrogels (with and without fluconazole). Performed analyses confirmed that polymeric hydrogels are excellent drug carriers and, when fluconazole-loaded, they may be applied as the prevention of chronic wounds fungal infection.

Application of Selected Nanomaterials and Ozone in Modern Clinical Dentistry.

This review is an attempt to summarize current research on ozone, titanium dioxide (TiO2), silver (Ag), copper oxide CuO and platinum (Pt) nanoparticles (NPs). These agents can be used in various fields of dentistry such as conservative dentistry, endodontic, prosthetic or dental surgery. Nanotechnology and ozone can facilitate the dentist's work by providing antimicrobial properties to dental materials or ensuring a decontaminated work area. However, the high potential of these agents for use in medicine should be confirmed in further research due to possible side effects, especially in long duration of observation so that the best way to apply them can be obtained.

Preparation of a New Biocomposite Designed for Cartilage Grafting with Antibiofilm Activity.

New polymer-inorganic composites with antibiofilm features based on the granulated poly(tetrafluoroethylene) (PTFE) and apatite materials were obtained using a standard hydraulic press. The study was performed in hydroxy- and fluorapatites doped with different amounts of silver ions and followed by heat treatment at 600 °C. The structural, morphological, and physicochemical properties were determined by X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy-energy-dispersive spectrometry (SEM-EDS), and transition electron microscopy (TEM). The antibacterial properties of the obtained materials were evaluated against Gram-negative pathogens such as Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli as well as against Gram-positive bacteria Staphylococcus epidermidis. The cytotoxicity assessment was carried out on the red blood cells (RBC) as a cell model for in vitro study. Moreover, the biofilm formation on the biocomposite surface was studied using confocal laser scanning microscopy (CLSM).

Preparation and Characterization of Self-Assembled Poly(l-Lactide) on the Surface of ß-Tricalcium Diphosphate(V) for Bone Tissue Theranostics.

This work was aimed to obtain and characterize the well-defined biocomposites based on ß-tricalcium diphosphate(V) (ß-TCP) co-doped with Ce3+ and Pr3+ ions modified by poly(l-lactide) (PLLA) with precise tailored chain length and different phosphate to polymer ratio. The composites as well as ß-tricalcium diphosphate(V) were spectroscopically characterized using emission spectroscopy and luminescence kinetics. Morphological and structural properties were studied using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The self-assembled poly(l-lactide) in a shape of rose flower has been successfully polymerized on the surface of the ß-tricalcium diphosphate(V) nanocrystals. The studied materials were evaluated in vitro including cytotoxicity (MTT assay) and hemolysis tests. The obtained results suggested that the studied materials may find potential application in tissue engineering.

Structural modification of nanohydroxyapatite Ca10(PO4)6(OH)2 related to Eu3+ and Sr2+ ions doping and its spectroscopic and antimicrobial properties.

The Eu3+ and Sr2+ ions co-doped hydroxyapatite nanopowders (Ca10(PO4)6(OH)2) were synthesized via a precipitation method and post heat-treated at 500 °C. The concentration of Eu3+ ions was established in the range of 0.5-5 mol% to investigate the site occupancy preference. The concentration of Sr2+ ions was set at 5 mol%. The structural and morphological properties of the obtained materials were studied by an X-ray powder diffraction, a transmission electron microscopy techniques and infrared spectroscopy. As synthesized nanoparticles were in the range of 11-17 nm and annealed particles were in the range of 20-26 nm. The luminescence properties in dependence of the dopant concentration and applied temperature were investigated. The 5D0 → 7F0 transition shown the abnormally strong intensity for annealed materials connected with the increase of covalency character of Eu3+-O2- bond, which arise as an effect of charge compensation mechanism. The Eu3+ ions occupied three possible crystallographic sites in these materials revealed in emission spectra: one Ca(1) site with C3 symmetry and two Ca(2) sites with Cs symmetry arranged as cis and trans symmetry. The antibacterial properties of Eu3+ and Sr2+ ions doped and co-doped hydroxyapatite nanopowders were also determined against Gram-negative pathogens such as Pseudomonas aeruginosa, Klebsiella pneumoniae and Escherichia coli. Obtained results suggest that both europium and strontium ions may implement antibacterial properties for hydroxyapatites. In the most cases, better antibacterial effect we noticed for dopants at 5 mol% ratio. However, the effect is strongly species- and strain-dependent feature.

Activity of gemini quaternary ammonium salts against microorganisms.

Quaternary ammonium salts (QAS), as the surface active compounds, are widely used in medicine and industry. Their common application is responsible for the development of microbial resistance to QAS. To overcome, this issue novel surfactants, including gemini-type ones, were developed. These unique compounds are built of two hydrophilic and two hydrophobic parts. The double-head double-tail type of structure enhances their physicochemical properties (like surface activity) and biological activity and makes them a potential candidate for new drugs and disinfectants. Antimicrobial activity is mainly attributed to the biocidal action towards bacteria and fungi in their planktonic and biofilm forms, but the mode of action of gemini QAS is not yet fully understood. Moreover, gemini surfactants are of particular interest towards their application as gene carriers. Cationic charge of gemini QAS and their ability to form liposomes facilitate DNA compaction and transfection of the target cells. Multifunctional nature of gemini QAS is the reason of the long-standing research on mainly their structure-activity relationship.