Comparison of the Visibility of Canine Menisci before and after Tibial Plateau Leveling Osteotomy: 3D-Printed Model Study.

The aim of this study was to compare the degree of visibility of the lateral and medial menisci before and after tibial plateau leveling osteotomy (TPLO) on 3D-printed models created after laser scanning of the right tibia with menisci derived from a fresh cadaver of a 4-year-old adult male golden retriever. The models were produced of white polylactic acid, and the menisci were filled with light-curing red resin. The models showed a similar conformation as the natural specimen harvested from the cadaver, maintaining the same length and width, in addition to reproducing the anatomical structures. From the pre- and post-TPLO radiographs, it was possible to identify the anatomical structures corresponding to the tibial plateau. The preoperative tibial plateau angle was 26.2°, and the postoperative one ranged between 4.0° and 5.3° (4.6 ± 0.4°). In the bird's-eye photo, the total number of red pixels in the lateral and the medial meniscus was 2,053,995 and 2,140,939, respectively. Before TPLO, only between 14% and 19% of the entire area of the menisci was visible, and the unhidden part of the entire area of the meniscus before TPLO did not differ significantly between the lateral (16.2 ± 1.6%) and the medial (16.4 ± 1.6%) meniscus (p = 0.351). The visible part of the entire meniscus area increased significantly after TPLO both in the lateral and medial menisci (p < 0.001)-mean difference ± SD of 30.3 ± 4.3% (CI 95%: 27.9%, 32.6%) and 36.4 ± 6.4% (CI 95%: 32.9%, 40.0%), respectively. In conclusion, the intraoperative examination and treatment of dog menisci are easier after TPLO.

PA-12-Zirconia-Alumina-Cenospheres 3D Printed Composites: Accelerated Ageing and Role of the Sterilisation Process for Physicochemical Properties.

The aim of this study was to conduct artificial ageing tests on polymer-ceramic composites prepared from polyamide PA-12 polymer matrix for medical applications and three different variants of ceramic fillers: zirconia, alumina and cenospheres. Before ageing, the samples were subjected to ethyl oxide sterilization. The composite variants were prepared for 3D printing using the fused deposition modeling method. The control group consisted of unsterilized samples. Samples were subjected to artificial ageing in a high-pressure autoclave. Ageing conditions were calculated from the modified Hammerlich Arrhenius kinetic equation. Ageing was carried out in artificial saliva. After ageing the composites were subjected to mechanical (tensile strength, hardness, surface roughness) testing, chemical and structural (MS, FTIR) analysis, electron microscopy observations (SEM/EDS) and absorbability measurements.

Cenospheres-Reinforced PA-12 Composite: Preparation, Physicochemical Properties, and Soaking Tests.

The main aim of this research was the preparation of a polymer-ceramic composite with PA-12 as the polymer matrix and modified aluminosilicate cenospheres (CSs) as the ceramic filler. The CSs were subjected to an early purification and cleaning process, which was also taken as a second objective. The CSs were surface modified by a two-step process: (1) etching in Piranha solution and (2) silanization in 3-aminopropyltriethoxysilane. The composite was made for 3D printing by FDM. Raw and modified CSs and a composite with PA-12 were subjected to the following tests: surface development including pores (BET), real density (HP), chemical composition and morphology (SEM/EDS, FTIR), grain analysis (PSD), phase composition (XRD), hardness (HV), and static tensile tests. The composites were subjected to soaking under simulated body fluid (SBF) conditions in artificial saliva for 14, 21, and 29 days. Compared to pure PA-12, PA-12_CS had generally better mechanical properties and was more resistant to SBF at elevated temperatures and soaking times. These results showed this material has potential for use in biomedical applications. These results also showed the necessity of developing a kinetic aging model for aging in different liquids to verify the true value of this material.

Assessment of encrustation and physicochemical properties of poly(lactide-glycolide) - Papaverine hydrochloride coating on ureteral double-J stents after long-term flow of artificial urine.

Implantation of ureteral stents is associated with inconvenience for the patient, which is related to the natural ability of the ureter to contract. The most frequently used solution is the systemic administration of a diastolic drug, which has a relaxing effect on smooth muscle cells and decreases inconvenience. Current interdisciplinary research aimed at reducing the complications after the implantation of ureteral stents used in the treatment of upper urinary tracts with regard to infection, initiation of encrustation, and fragmentation of stents, and patient pain has not been resolved. This study presents the results of research regarding the impact of a biodegradable coating with the active substance on the physical and chemical properties of ureteral stents used in the treatment of the upper urinary tract. The surface of polyurethane double-J stents was coated with poly(lactide-glycolide) (PLGA) 85/15 loaded with papaverine hydrochloride (PAP) with diastolic properties. The coating for ureteral stents has been designed for short-term implantation. The effect of the coating on the process of encrustation and PAP release by the dynamic in vitro model with artificial urine (AU) up to 30 days was evaluated. The influence of AU on the physical and chemical properties of ureteral stents was determined. As part of the study, surface structure and topography researches; chemical composition analyses using X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and wetting; and surface roughness studies of both PUR stents and coated stents were carried out. The proposed biodegradable PLGA+PAP coating is characterized by controlled drug release, while optimal physicochemical properties does not increase the encrustation process.

Modern methods of surface modification for new-generation titanium alloys.

The constantly growing need for the use of implants in osteotomy is mainly due to the aging population and the need for long-term use of this type of biomaterials. Improving implant materials requires the selection of appropriate functional properties. Currently used titanium (Ti) alloys, such as Ti6Al4V and Ti6Al7Nb, are being replaced by materials with better biocompatibility, such as vanadium (V) or niobium (Nb), allowing for creation of the so-called new generation alloys. These new alloys, with the incorporation of zirconium (Zr), iron, and tantalum, possess Young's modulus close to that of a bone, which further improves the improves the biomaterial's. biocompatibility. This article describes the atomic layer deposition (ALD) method and its possible applications in the new generation of titanium alloys for biomedical applications. Also, the exemplary results of tin oxide (SnO2) thin coatings deposited by ALD and physical vapor deposition (PVD) methods are presented. This study aimed to evaluate the physicochemical properties of a Ti13Nb13Zr alloy used for elements in the skeletal system. As the temperature and the number of cycles vary, the results demonstrate that the surface area of the samples changes. The uncoated Ti13Nb13Zr alloy exhibits hydrophilic properties. However, all coated specimens improve in this respect and provide improved clinical results. after the applied modification, the samples have a smaller contact angle, but still remain in the range of 0-90°, which makes it possible to conclude that their nature remains hydrophilic. Coating the specimens decreased the mineralization risk of postoperative complications. As a result, the biomaterials demonstrated improved effectiveness, decreased complication indicators, and improved patient well-being.

Effect of Calcination Temperature on the Phase Composition, Morphology, and Thermal Properties of ZrO2 and Al2O3 Modified with APTES (3-aminopropyltriethoxysilane).

This paper describes the effect of calcination temperature on the phase composition, chemical composition, and morphology of ZrO2 and Al2O3 powders modified with 3-aminopropyltriethoxysilane (APTES). Both ceramic powders were modified by etching in piranha solution, neutralization in ammonia water, reaction with APTES, ultrasonication, and finally calcination at 250, 350, or 450 °C. The obtained modified powders were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, particle size distribution (PSD), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS), and thermogravimetric analysis (TGA).

Alumina and Zirconia-Reinforced Polyamide PA-12 Composites for Biomedical Additive Manufacturing.

This work aimed to prepare a composite with a polyamide (PA) matrix and surface-modified ZrO2 or Al2O3 to be used as ceramic fillers (CFs). Those composites contained 30 wt.% ceramic powder to 70 wt.% polymer. Possible applications for this type of composite include bioengineering applications especially in the fields of dental prosthetics and orthopaedics. The ceramic fillers were subjected to chemical surface modification with Piranha Solution and suspension in 10 M sodium hydroxide and Si3N4 to achieve the highest possible surface development and to introduce additional functional groups. This was to improve the bonding between the CFs and the polymer matrix. Both CFs were examined for particle size distribution (PSD), functional groups (FTIR), chemical composition (XPS), phase composition (XRD), and morphology and chemical composition (SEM/EDS). Filaments were created from the powders prepared in this way and were then used for 3D FDM printing. Samples were subjected to mechanical tests (tensility, hardness) and soaking tests in a high-pressure autoclave in artificial saliva for 14, 21, and 29 days.

Development of Novel Thin Polycaprolactone (PCL)/Clay Nanocomposite Films with Antimicrobial Activity Promoted by the Study of Mechanical, Thermal, and Surface Properties.

Infection with pathogenic microorganisms is of great concern in many areas, especially in healthcare, but also in food packaging and storage, or in water purification systems. Antimicrobial polymer nanocomposites have gained great popularity in these areas. Therefore, this study focused on new approaches to develop thin antimicrobial films based on biodegradable polycaprolactone (PCL) with clay mineral natural vermiculite as a carrier for antimicrobial compounds, where the active organic antimicrobial component is antifungal ciclopirox olamine (CPX). For possible synergistic effects, a sample in combination with the inorganic antimicrobial active ingredient zinc oxide was also prepared. The structures of all the prepared samples were studied by X-ray diffraction, FTIR analysis and, predominantly, by SEM. The very different structure properties of the prepared nanofillers had a fundamental influence on the final structural arrangement of thin PCL nanocomposite films as well as on their mechanical, thermal, and surface properties. As sample PCL/ZnOVER_CPX possessed the best results for antimicrobial activity against examined microbial strains, the synergic effect of CPX and ZnO combination on antimicrobial activity was proved, but on the other hand, its mechanical resistance was the lowest.

Functional Properties of Polyurethane Ureteral Stents with PLGA and Papaverine Hydrochloride Coating.

Despite the obvious benefits of using ureteral stents to drain the ureters, there is also a risk of complications from 80-90%. The presence of a foreign body in the human body causes disturbances in its proper functioning. It can lead to biofilm formation on the stent surface, which may favor the development of urinary tract infections or the formation of encrustation, as well as stent fragmentation, complicating its subsequent removal. In this work, the effect of the polymeric coating containing the active substance-papaverine hydrochloride on the functional properties of ureteral stents significant for clinical practice were assessed. Methods: The most commonly clinically used polyurethane ureteral Double-J stent was selected for the study. Using the dip-coating method, the surface of the stent was coated with a poly(D,L-lactide-glycolide) (PLGA) coating containing the papaverine hydrochloride (PAP). In particular, strength properties, retention strength of the stent ends, dynamic frictional force, and the fluoroscopic visibility of the stent during X-ray imaging were determined. Results: The analysis of the test results indicates the usefulness of a biodegradable polymer coating containing the active substance for the modification of the surface of polyurethane ureteral stents. The stents coated with PLGA+PAP coating compared to polyurethane stents are characterized by more favorable strength properties, the smaller value of the dynamic frictional force, without reducing the fluoroscopic visibility.

Selected Physicochemical Properties of Diamond Like Carbon (DLC) Coating on Ti-13Nb-13Zr Alloy Used for Blood Contacting Implants.

Despite high interest in the issues of hemocompatibility of titanium implants, particularly those made of the Ti-13Nb-13Zr alloy, the applied methods of surface modification still do not always guarantee the physicochemical properties required for their safe operation. The factors that reduce the efficiency of the application of titanium alloys in the treatment of conditions of the cardiovascular system include blood coagulation and fibrous proliferation within the vessel's internal walls. They result from their surfaces' physicochemical properties not being fully adapted to the specifics of the circulatory system. Until now, the generation and development mechanics of these adverse processes are not fully known. Thus, the fundamental problem in this work is to determine the correlation between the physicochemical properties of the diamond like carbon (DLC) coating (shaped by the technological conditions of the process) applied onto the Ti-13Nb-13Zr alloy designed for contact with blood and its hemocompatibility. In the paper, microscopic metallographic, surface roughness, wettability, free surface energy, hardness, coating adhesion to the substrate, impendence, and potentiodynamic studies in artificial plasma were carried out. The surface layer with the DLC coating ensures the required surface roughness and hydrophobic character and sufficient pitting corrosion resistance in artificial plasma. On the other hand, the proposed CrN interlayer results in better adhesion of the coating to the Ti-13Nb-13Zr alloy. This type of coating is an alternative to the modification of titanium alloy surfaces using various elements to improve the blood environment's hemocompatibility.

Impact of Surface Treatment on the Functional Properties Stainless Steel for Biomedical Applications.

The main goal of the carried out tests was to analyze the influence of the surface modification of a substrate by depositing composite ZnO layers by the Atomic Layer Deposition (ALD) method. The samples were subjected to preliminary surface modification consisting of being sandblasted and electropolished. A ZnO layer was applied to the prepared substrates by the ALD method. As a precursor of ZnO, diethylzinc (DEZ) was used, which reacted with water, enabling the deposition of the thin films. The chamber temperature was as follows: T = 100-300 °C. The number of cycles was 500 and 1500. As part of the assessment of the physicochemical properties of the resulting surface layers, the tests of chemical composition of the layer, pitting corrosion, impedance corrosion, adhesion to the metal substrate, morphology surface, and wettability were carried out. On the basis of the obtained research, it was found that a composite ZnO layer deposited onto a substrate previously subjected to the electrochemical polishing process has more favorable physicochemical properties. Moreover, an influence of temperature and the number of cycles of the deposition process on the obtained properties was observed, where the ZnO layer was characterized by more favorable properties at a temperature of 200-300 °C at 1500 cycles of the deposition process.

Electrochemical and Biological Performance of Biodegradable Polymer Coatings on Ti6Al7Nb Alloy.

The inhibition of the corrosion of metal implants is still a challenge. This study aimed to increase the corrosion resistance of Ti6Al7Nb alloy implants through surface modification, including grinding, sandblasting, and anodic oxidation followed by the deposition of a polymer coating. The aim of the work was to determine the influence of biodegradable polymer coatings on the physico-chemical properties of a Ti6Al7Nb alloy used for short-term implants. Biodegradable coatings prepared from poly(glycolide-caprolactone) (P(GCap)), poly(glycolide ε-caprolactone-lactide) (P(GCapL)), and poly(lactide-glycolide) (PLGA) were applied in the studies. The dip-coating method with three cycles of dipping was applied. Corrosion resistance was assessed on the basis of potentiodynamic studies. The studies were carried out on samples after 30, 60, and 90 days of exposure to Ringer's solution. Surface topography, wettability, and cytotoxicity studies were also carried out. The degradation process of the base material was evaluated on the basis of the mass density of the metal ions released to the solution. The results indicated the influence of the coating type on corrosion resistance. In addition, a beneficial effect of the polymer coating on the reduction of the density of the released metal ions was found, as compared to the samples without polymer coatings. The obtained results provide basic knowledge for the development of polymer coatings enriched with an active substance. The presence of ciprofloxacin in the coating did not reduce the corrosion resistance of the metal substrate. Moreover, the cytotoxicity test using the extract dilution method demonstrated that the implants' coatings are promising for further in vitro and in vivo studies.

Biodegradable polymer coatings on Ti6Al7Nb alloy.

The aim of the study was to determine the influence of long term exposure to Ringer's solution of biodegradable polymer coatings containing an active substance on the Ti6Al7Nb alloy substrate on the physical and chemical properties of the coatings and the degradation process of the metal substrate. The studies used poly(L-lactide-co-trimethylene carbonate) P(L/TMC), poly(L-lactide-co-trimethylene carbonate-glycolide) P(L/TMC/G) and poly(D,L-lactide-glycolide) (PLGA) coatings applied to the anodically oxidized Ti6Al7Nb alloy by means of dipping method (1, 2 and 3 dips). The polymer coatings contained ciprofloxacin. Roughness and wettability tests were carried out on the substrate and polymer coatings, the pitting corrosion resistance of the substrate and samples with polymer coating was determined, the number of metallic ions released to the solution from the coated and uncoated samples was determined as well as the adhesion of polymer coatings. The research was supplemented by microscopic observations. The results of the research indicate different influence of exposure to Ringer's solution on the physical and chemical properties of biodegradable polymer coatings containing ciprofloxacin and the course of the degradation process of the metal substrate.