Angle Measurements Research Articles

Trochlear Morphological Changes in Skeletally Immature Patients Across Consecutive MRI Studies.

Trochlear dysplasia is a consistent risk factor for recurrent patellofemoral instability (PFI), but there is limited understanding of how the trochlea develops during growth. The aim of this study was to evaluate serial magnetic resonance imaging (MRI) studies performed in skeletally immature patients with and without PFI to characterize changes in trochlear anatomy over time. PFI leads to progressive worsening of trochlear dysplasia over time. Cohort study; Level of evidence, 3. A retrospective case-control study was conducted on pediatric patients (<18 years of age) with and without a diagnosis of PFI who had multiple ipsilateral MRI studies of the knee at least 6 months apart. Inclusion criteria were patients with open distal femoral physes at the initial MRI study and no intervening surgery between MRI studies. All patients with PFI were included, and 30 patients without PFI were identified for comparison. MRI scans were retrospectively reviewed to evaluate trochlear morphology using the Dejour and Oswestry-Bristol classifications and to measure the sulcus angle, trochlear depth index, medial condylar trochlear offset, and lateral trochlear inclination (LTI). Univariate and bivariate statistics were performed to evaluate differences in morphology between MRI studies and between groups. A total of 128 patients were identified (98 in the PFI group, 30 in the non-PFI group) with a mean age of 12.3 ± 2.4 years and mean time between MRI studies of 2.3 ± 1.5 years (range, 0.5-6.5 years). Among patients with PFI, rates of moderate to severe (Dejour grades B-D and Oswestry-Bristol classification flat or convex) trochlear dysplasia increased from the initial to most recent imaging study (67% vs 89%; P < .001), and statistically significantly more dysplastic LTI and sulcus angle were observed on follow-up (P < .05). Among the non-PFI group, the percentage of patients with normal trochlear morphology increased from 53% to 87% (P < .001), and less dysplastic measures of trochlear depth index, LTI, and sulcus angle were seen on follow-up imaging (P < .05). When comparing rates of change, trochlear metrics changed toward a more shallow and dysplastic direction in the PFI cohort and toward a deeper and less dysplastic direction in the non-PFI group. Skeletally immature patients with untreated PFI have trochlear dysplasia that progressively worsens over time. Conversely, those without PFI have trochlear characteristics that appear to normalize with growth.

Unlocking Probiotic Potential: Physicochemical Approaches to Evaluate Probiotic Bacterial Adhesion Potential to the Intestinal Tract.

Bacterial adhesion in the gut is critical to evaluate their effectiveness as probiotics. Understanding the bacterial adhesion within the complex gut environment is challenging. This study explores the adhesion mechanisms and the adhesion potential of five selected bacterial strains (Escherichia coli, Lactiplantibacillus plantarum, Faecalibacterium duncaniae, Bifidobacterium longum, and Bifidobacterium longum subsp. infantis) at the initial stages when bacterial cells arriving in the gut, using different physicochemical approaches. Bacterial morphology, rheology, and surface properties were evaluated. Surprisingly, previous methods such as bacterial adhesion to hydrocarbon and the interfacial tension between bacterial suspensions and mineral oil did not fully capture the bacterial adhesion to intestinal mucus. Consequently, this study introduced a novel approach to assess bacterial adhesion to mucus, based on contact angle measurements, calculation of surface tension, and work of adhesion. Interestingly, both small and large intestinal mucus are rather hydrophilic, and thus highly hydrophilic bacteria such as E. coli and B. infantis tend to adhere better. Additionally, a multicriteria evaluation of bacterial adhesion to the gut, from the bulk liquid transport stage until the irreversible adhesion, was proposed. E. coli and B. infantis demonstrated the highest overall adhesion potential in the intestinal tract, followed by Lpb. plantarum, B. longum, and F. duncaniae, respectively. This work contributed original physicochemical approaches to comprehensively examine bacterial adhesion in the gut.

Isoelectric Point of Metal Oxide Films Formed by Anodization.

The surface charge of metal oxides is an important property that significantly contributes to a wide range of phenomena, including adsorption, catalysis, and material science. The surface charge can be predicted by determining the isoelectric point (IEP) of a material and the pH of a solution. Although there have been several studies of the IEP of metal oxide (nano)particles, only a few have reported the IEP of metal oxide films. The IEP of various compact metal oxide films such as TiO2, Nb2O5, WO3, ZrO2, NiO, and Al2O3 formed via electrochemical anodization was determined using the streaming potential technique. Nanostructured TiO2 and NiO were additionally produced using a single-step anodization technique, and their IEP was compared with the compact ones. The surface morphology and wettability of the oxides were studied by scanning electron microscopy and contact angle measurements, respectively. X-ray powder diffraction and X-ray photoelectron spectroscopy measurements were carried out to assess the phase and elemental composition, respectively. The IEP of compact anodic oxides deviates from that of their nanoparticle and atomic layer-deposited counterparts. The comparative results indicate that the IEP of metal oxides is influenced by factors such as the chemical composition, degree of hydroxylation, and crystallographic phases of the oxide.

Structure and properties of chitosan plasticized with hydrophobic short-chain fatty acid cosolvent.

The application of chitosan in packaging has always been limited due to its brittle and hygroscopic nature. In this study, hydrophobic short-chain fatty acids (SCFAs) were utilized to modify chitosan to overcome this issue. For the first time, hydrophobic SCFAs, typically hexanoic acid and its homologs, were found to be able to dissolve chitosan in water as well as its hydrophilic analog. After water was removed through evaporation, hydrophobic SCFA-modified chitosan films were obtained. The results of mechanical testing and DSC analysis confirmed that these hydrophobic SCFAs could effectively plasticize the chitosan film. Moreover, water contact angle measurements revealed that the hydrophilicity of these plasticized chitosan films was significantly reduced. The findings from the moisture uptake experiments indicated that linear hydrophobic SCFAs reduced the hygroscopicity of the chitosan film. Additionally, the crystal structures, thermal and gas barrier properties, and antibacterial activities of these hydrophobic SCFA-modified films were systematically examined and compared with those of hydrophilic SCFA-modified chitosan. This study presents an innovative and practical method for modifying chitosan films by regulating the structure of the cosolvent, thereby facilitating the real-world application of chitosan-based food packaging materials.

Facile Fabrication of Multifunctional Superhydrophobic Surfaces Synthesized by the Additive Manufacturing Technique Modified with ZnO Nanoparticles.

This article reports facile fabrication of a multifunctional smart surface having superhydrophobic self-cleaning property, superoleophilicity, and antimicrobial property. These smart surfaces have been synthesized using the stereolithography (SLA) method of the additive manufacturing technique. SLA is a fast additive manufacturing technique used to create complex parts with intricate geometries. A wide variety of materials and high-resolution techniques can be utilized to create functional parts such as superhydrophobic surfaces. Various materials have been studied to improve the functionality of 3D printing. However, the fabrication of such materials is not easy, as it is quite expensive. In this work, we used a commercially available SLA printer and its photopolymer resin to create various micropatterned surfaces. Additionally, we applied a low surface energy coating with ZnO nanoparticles and tetraethyl orthosilicate to create hierarchical roughness. The wettability studies of created superhydrophobic surfaces were evaluated by means of static contact angle using the sessile drop method and rolling angle measurements. The effects of various factors, including different concentrations of coating mixture, drying temperatures, patterns (pyramids, pillars, and eggbeater structures), and pillar spacing, were studied in relation to contact angles. Subsequently, all the functional properties (i.e., self-cleaning, oleophilicity, and antibacterial properties) of the as-obtained surfaces were demonstrated using data, images, and supporting videos. This inexpensive and scalable process can be easily replicated with an SLA 3D printer and photopolymer resin for many applications such as self-cleaning, oil-water separation, channel-less microfluidics, antibacterial coating, etc.

Swelling Degree of Polyelectrolyte Layers Determined by an Electrochemical Quartz Crystal Microbalance.

Various polycations and polyanions were sequentially adsorbed onto the gold electrode of a quartz crystal microbalance with dissipation monitoring. The study focused on determining the adsorption kinetics, viscoelastic properties, and electroresponsivity of polyelectrolyte layers. For the first time, it was demonstrated that the structure (compact or expanded) of the layers can be determined by electroresponsivity. Viscoelastic modeling alone did not provide a conclusive answer as to whether the layers were compact or expanded. The study was further enriched by streaming potential and contact angle measurements, where polyelectrolyte multilayers were formed on mica. It was found that successive adsorption of layers led to periodic inversion of the zeta potential. Systematic differences were observed between the different top layers, which were explained by intermixing between layers. The presence or absence of interpenetration, as determined by the measurements of streaming potential and contact angles, correlated well with electroresponsivity.

Interaction studies unveil potential binding sites on bovine serum albumin for gut metabolite trimethylamine n-oxide (TMAO)

Trimethylamine-N-oxide (TMAO) is gut microbiota-derived metabolite, plays a critical role in human health and diseases such as metabolic, cardiovascular, colorectal cancer and, neurological disorders. Binding interactions between TMAO and serum albumins are crucial to understand the impact of TMAO on disease mechanisms. However, detailed insights into the interaction mechanisms, preferred binding locations, and conformational changes in BSA upon binding TMAO are still unclear. TMAO interacts with serum albumin in human body and thus, a model study of interaction for TMAO-BSA conjugate is presented in support of it. Decrease in absorbance intensity of protein upon interaction with metabolites reveals conjugate formation, while fluorescence spectroscopy indicate static quenching. Contact angle measurements further reveal the hydrophilic nature of the TMAO-BSA complex, while CD and FTIR support conformational changes in BSA upon binding but structure remain intact. Computational studies, such as molecular docking, molecular dynamics simulation and, MM/GBSA, confirm a stable complex with a binding energy of − 3.6 kcal/mol. These findings provide a foundation for understanding the pharmacodynamics and pharmacokinetics of TMAO and may aid in developing strategies for treating diseases, such as chronic kidney disease and neurological disorder where TMAO-serum albumins interaction are implicated.

Films Based on Chitosan/Konjac Glucomannan Blend Containing Resveratrol for Potential Skin Application.

Biopolymers represent a significant class of materials with potential applications in skin care due to their beneficial properties. Resveratrol is a natural substance that exhibits a range of biological activities, including the scavenging of free radicals and anti-inflammatory and anti-aging effects. In this study, chitosan/konjac glucomannan resveratrol-enriched thin films were prepared. The enrichment of biomaterials with active ingredients is a common practice, as it allows the desired properties to be obtained in the final product. To characterize the films, several analyses were performed, including infrared spectroscopy, imaging of the samples by SEM and AFM techniques, swelling analysis in pH 5.5 and 7.4, mechanical and antioxidant assays, contact angle measurements, and determination of the resveratrol release profile under the skin mimicking conditions. Resveratrol incorporation into the matrices resulted in modifications to the chemical structure and film morphology. The mechanical characteristics of films with additives were found to undergo deterioration. The sample containing 10% of resveratrol exhibited a higher swelling degree than other films. The resveratrol-modified films demonstrated a notable antioxidant capacity, a reduced contact angle, and enhanced wettability. The resveratrol release occurred rapidly initially, with a maximum of 84% and 56% of the substance released depending on the sample type. Thus, the proposed formulations have promising properties, in particular good swelling capacity, high antioxidant potential, and improved wettability, and may serve as skin dressings after further investigation.

Development of a Sustainable Flexible Humidity Sensor Based on Tenebrio molitor Larvae Biomass-Derived Chitosan.

This study presents the fabrication of a sustainable flexible humidity sensor utilizing chitosan derived from mealworm biomass as the primary sensing material. The chitosan-based humidity sensor was fabricated by casting chitosan and polyvinyl alcohol (PVA) films with interdigitated copper electrodes, forming a laminate composite suitable for real-time, resistive-type humidity detection. Comprehensive characterization of the chitosan film was performed using Fourier-transform infrared (FTIR) spectroscopy, contact angle measurements, and tensile testing, which confirmed its chemical structure, wettability, and mechanical stability. The developed sensor exhibited a broad range of measurements from 6% to 97% relative humidity (RH), a high sensitivity of 2.43 kΩ/%RH, and a rapid response time of 18.22 s with a corresponding recovery time of 22.39 s. Moreover, the chitosan-based humidity sensor also demonstrated high selectivity for water vapor when tested against various volatile organic compounds (VOCs). The superior performance of the sensor is attributed to the structural properties of chitosan, particularly its ability to form reversible hydrogen bonds with water molecules. This mechanism was further elucidated through molecular dynamics simulations, revealing that the conductivity in the sensor is modulated by proton mobility, which operates via the Grotthuss mechanism under high-humidity and the packed-acid mechanism under low-humidity conditions. Additionally, the chitosan-based humidity sensor was further seamlessly integrated into an Internet of Things (IoT) framework, enabling wireless humidity monitoring and real-time data visualization on a mobile device. Comparative analysis with existing polymer-based resistive-type sensors further highlighted the superior sensing range, rapid dynamic response, and environmental sustainability of the developed sensor. This eco-friendly, biomass-derived, eco-friendly sensor shows potential for applications in environmental monitoring, smart agriculture, and industrial process control.

Application of synthesized Fe3O4@Gelatin nanoparticles on interfacial properties and enhanced oil recovery

Due to the unique properties of nanoparticles (NPs), their application has been proposed as an innovative and promising enhanced oil recovery (EOR) technique. They enhance oil recovery by improving EOR mechanisms including decreasing interfacial tension (IFT), wettability alteration to water-wet, and preventing asphaltene precipitation. In this study, Fe3O4@Gelatin NPs were synthesized by a convenient and single-step method and then investigated for EOR purposes for the first time. These NPS were characterized by Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). Afterward, various experiments including contact angle, interfacial tension (IFT), and micromodel flooding were performed to evaluate the capability of Fe3O4@Gelatin NPs for EOR application. Based on the results of IFT measurements, the synthesized NPs caused the highest reduction in IFT of crude oil-seawater compared to Fe3O4 NPs and gelatin. This significant reduction is due to the synergistic effects of Fe3O4 NPs and gelatin in the form of a nanocomposite. According to the results from contact angle measurements, the Fe3O4@Gelatin NPs could significantly change the glass surface wettability from oil-wet to water-wet, which showed a better performance than Fe3O4 NPs. The surface modification of Fe3O4 NPs with gelatin causes to enhance the capability of these NPs for wettability alteration because the gelatin has surface active property. In the micromodel flooding tests, the seawater containing 0.06 wt. % Fe3O4@Gelatin NPs had the highest oil recovery factor (RF = 42.9%) compared to the seawater containing 0.06 wt. % Fe3O4 NPs (RF = 33.92%) and only seawater (RF = 26.57%), due to more IFT reduction and altering the surface wettability from oil-wet to strongly water-wet. Therefore, according to the results of this research, the synthesized NPs can be a good option for EOR.

Ultra-low tilt angle measurement using temporal phase shifting in Sagnac interferometer

Temporal phase shifting has been achieved in the Sagnac interferometer for the first time. To achieve this phase shifting, a rectangular parallel glass plate is introduced into one half of the beam, leaving the other half without a parallel glass plate. When rotation is applied to the parallel glass plate, phase shifting occurs. This technique is used to measure the ultra-low tilt angle given to one of the mirrors of the Sagnac interferometer. In this study, we also elaborate on the method to determine the initial angle (rotation angle) of the parallel glass plate with respect to the beam direction. The design of the interferometer, theory for temporal phase shifting, tilt angle measurement, and finding the initial angle of the parallel glass plate are explained, and experimental results with error analysis are presented to verify them.

Effect of different addition orders of petrochemical by-product-based mixed collectors on coal flotation

ABSTRACT An effective collector is crucial for enhancing coal flotation efficiency. The effect of a mixed collector based on petrochemical by-products on coal flotation was investigated. The investigation included various addition orders and was conducted using flotation tests, particle size distribution analysis, GC-MS, FTIR and contact angle measurements. The Mixed addition order exhibited superior performance in flotation compared to the K+Y and Y+K orders at all tested dosages. Particle size distribution analyses revealed that the mixed collector offered better dispersion in water than individual the Y-oil and K-oil, with droplet sizes below 100 µm. FTIR and contact angle measurements indicated that coal treated with the Mixed addition order demonstrated optimal reagent adsorption and the highest level of surface hydrophobicity. Aromatic compounds in the collector interacted with the hydrophobic areas of the coal surface, while partially covering some of the hydrophilic regions between these hydrophobic sites. Conversely, heteropolar components engaged with the hydrophilic regions on the coal surface to enhance adsorption. Despite these improvements, some hydrophilic sites remained after treatments with the Y+K and K+Y orders, which continued to affect the coal flotation properties.

Sodium Trithiocarbonate as a Promising Sulfidizing Agent for Efficient and Green Recovery of Azurite: Flotation Properties and Interaction Mechanism.

The sulfidization-xanthate flotation process has been used commercially with some success in recovering azurite, but it remains unsatisfactory in terms of the environmental impact and flotation index. To remediate these deficiencies, this study evaluated the flotation performance of sodium trithiocarbonate (Na2CS3) as a green sulfidizing agent for azurite. Flotation test results demonstrated that Na2CS3 has the same efficacy as sodium sulfide but markedly superior activation performance. At one-fifth the dose, the maximum flotation recovery for Na2CS3 is about 20 percentage points higher than that observed for sodium sulfide. Contact angle measurements and field emission scanning electron microscopy analysis revealed that Na2CS3 modifies the pristine azurite surface by forming a relatively uniform sulfur-rich layer composed of nanoparticles, which in turn increases the collector efficacy and thus improves flotation recovery. The results of X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry further suggest that this sulfur-rich hydrophobic layer could be cuprous trithiocarbonate. The reduction of Cu(II) in the azurite lattice is considered a key step in forming the sulfur-rich layer, and the resultant Cu(I) interacts with Na2CS3 through the latter's carbon-sulfur bonds. The results of this study will facilitate the development of better technologies to process copper oxide ores.

Influence of Graphene, Hydroxyapatite, and Hydroxyapatite‐Niobium Pentoxide Nanoparticles on Polycaprolactone Electrospun Fibers Mats Properties

ABSTRACTPolycaprolactone (PCL) electrospun fiber mats containing varying concentrations of graphene flakes (GF), hydroxyapatite (HAp), and hydroxyapatite with niobium pentoxide (HAp5Nb) were successfully prepared by electrospinning. These composites exhibit great potential in biomedical applications, particularly as scaffolds for bone tissue engineering. The addition of GF enhances the rheological properties of the PCL solution due to the intrinsic properties resulting from their interactions. Additionally, incorporating HAp and HAp5Nb nanoparticles increases the viscosity of PCL‐based solutions, leading to the formation of thinner fiber diameters. The GF, HAp, and HAp5Nb nanoparticles were characterized using transmission electron microscopy (TEM) and x‐ray diffractometry (XRD), while the degree of disorder and heterogeneity of GF was assessed using Raman spectroscopy. The physical and chemical properties of the electrospun fiber mats were also characterized by scanning electron microscopy (SEM), XRD, fourier‐transform infrared spectroscopy (FTIR), and contact angle measurements. The cytotoxicity of PCL‐based electrospun fiber mats containing GF, HAp, and HAp5Nb nanoparticles was evaluated using mouse fibroblasts. Results showed that cell viability with 100% extract from the fiber mats was higher than with pure PCL or Dulbecco's modified Eagle's medium DMEM control, indicating that the samples were non‐toxic and promoted cell growth. This highlights their potential as scaffolds for bone tissue engineering.

Self-powered ultraviolet position-sensitive detectors based on PrNiO3/Nb-doped SrTiO3 p–n junctions

Position-sensitive detectors based on the lateral photovoltaic effect have been widely used in optical engineering for the measurement of position, distance, and angles. However, self-powered ultraviolet position-sensitive detectors with high sensitivity and fast response are still lacking due to the difficulty associated with the fabrication of p-type wide bandgap semiconductors, which hinders their further design and enhancement. Here, the influence of band structures and interfacial transport properties on the performance of self-powered ultraviolet position-sensitive detectors based on PrNiO3/Nb:SrTiO3p–n junctions is systematically investigated. Large position sensitivity and fast relaxation time of the lateral photovoltaic effect were observed up to 400 K in the perovskite-based ultraviolet position-sensitive detectors. Hall effect measurements revealed that the transport of photoexcited carriers occurs mainly through the interface of the PrNiO3/Nb:SrTiO3 junctions, resulting in a fast response and a stable photovoltaic effect. This study presents insights and avenues for designing self-powered perovskite oxide ultraviolet position-sensitive detectors with enhanced photoelectric performance.

Novel Ultrafiltration Polyethersulfone Membranes Blended with Carrageenan.

The development of ultrafiltration (UF) polymeric membranes with high flux and enhanced antifouling properties bridges a critical gap in the polymeric membrane fabrication research field. In the present work, the preparation of novel PES membranes incorporated with carrageenan (CAR), which is a natural polymer derived from edible red seaweed, is reported for the first time. The PES/CAR membranes were prepared by using the nonsolvent-induced phase separation (NIPS) method at 0.1-4.0 wt.% CAR loadings in the casting solutions. The use of dimethylsulfoxide (DMSO), which is a bio-based and low-toxic solvent, is reported. Scanning electron microscopy, atomic force microscopy, water contact angle, porosity, and zeta potential measurements were used to evaluate the surface morphology, structure, pore size, hydrophilicity, and surface charge of the prepared membranes. The filtration performance of PES/CAR membranes was tested with bovine serum albumin (BSA) solutions. It was shown that CAR incorporation in the casting solutions notably increased hydrophilicity, porosity, pore size, surface charge, and fouling resistance of the prepared membranes compared with plain PES membranes due to the hydrophilic nature and pore-forming properties of CAR. The PES/CAR membranes showed a significant reduction in irreversible and total fouling during filtration of BSA solutions by 38% and 32%, respectively, an enhancement in the flux recovery ratio by 20-40%, and an improvement in mechanical properties by 1.5-fold when compared with plain PES membranes. The findings of the present study indicate that CAR can be used as a promising additive for the development of PES UF membranes with enhanced properties and performance for water treatment applications.

Plasma Treatment of Metal Surfaces for Enhanced Bonding Strength of Metal-Polymer Hybrid Structures.

The adhesion between metals and polymers plays a pivotal role in numerous industrial applications, especially within the automotive and aerospace sectors, where there is a growing demand for materials that are both lightweight and durable. This study introduces an innovative technique to improve the adhesion between a metal and a polymer in hybrid structures through the synergistic use of anodization and plasma treatment. By forming a nanoporous oxide layer on aluminum surfaces, anodization enhances the interface for polymer binding. Plasma treatment further augments the surface properties by increasing the concentration of functional groups, thus allowing better polymer infiltration during the 3D printing process. Comprehensive analyses, including X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, and contact angle measurements confirm the substantial enhancement in the bonding strength achieved through this method. Additionally, cross-sectional analysis via focused ion-beam etching provides a detailed view of polymer integration into the treated layers. The findings suggest significant potential for these surface modification strategies to advance the development of lightweight, robust composites suitable for use in sectors such as automotive, aerospace, and consumer electronics.

Scoliosis progression after lung transplantation.

Scoliosis is a potential postoperative complication of various pediatric cardiothoracic conditions. To investigate the incidence of scoliosis in pediatric lung transplant patients and explore the factors associated with its development. Retrospective observational study. About 330 consecutive lung transplant recipients at a single institution between April 2002 and June 2022. The incidence of scoliosis. After excluding 45 patients with <1 year of follow-up, 285 patients were analyzed: 43 pediatric (≤17 years) and 242 adult (>18 years) patients. Data on baseline demographics, Cobb angle measurements pre- and posttransplant, and lung volumes at 1-year posttransplant in pediatric patients were collected. The prevalence of scoliosis was compared between pediatric and adult patients. Additionally, the impact of lung volume differences (right minus left) on scoliosis progression was assessed. Pediatric (n=43) and adult (n=242) patients had a mean age of 10.3 and 44.9 years, respectively. Scoliosis was significantly more prevalent in pediatric patients, with 30.2% having a Cobb angle >10° and 13.9% having a Cobb angle >20°, compared to 11.5% and 1.6% in adults, respectively. Pediatric patients with Cobb angles >20° exhibited significant lung volume differences 1-year posttransplant. Lung volume disparities increased the risk of scoliosis progression, particularly in patients with unilateral lung collapse. Pediatric lung transplant recipients have a higher incidence of significant scoliosis than adult recipients. Posttransplant lung volume disparities, especially in cases of unilateral lung collapse, may contribute to scoliosis progression. Routine spinal assessments are necessary for managing scoliosis in pediatric lung transplant patients to prevent curvature progression and ensure long-term musculoskeletal health.

Enhancing the biological characteristics of aminolysis surface-modified 3D printed nanocomposite polycaprolactone/nanohydroxyapatite scaffold via gelatin biomacromolecule immobilization: An in vitro and in vivo study.

The surface characteristics of scaffolds utilized in bone tissue engineering profoundly influence subsequent cellular response. This study investigated the efficacy of applying a gelatin coat to the surface of aminolysis surface-modified scaffolds fabricated through 3D printing with a polycaprolactone/hydroxyapatite nanocomposite, employing the hot-melt extrusion FDM technique. Initially, aminolysis surface modification using hexamethylenediamine enhanced surface hydrophilicity by introducing amine functional groups. Subsequently, gelatin solutions were applied to the scaffolds, and crosslinking with EDC/NHS was performed to increase coating strength. Contact angle measurements revealed a significantly increased surface hydrophilicity post-aminolysis. Aminolysis facilitated uniform gelatin coating formation and distribution. Subsequently, crosslinking enhanced coating durability. The addition of gelatin coating resulted in a notable 20 % increase in scaffold mechanical strength and more than 50 % rise in Young's modulus and exhibited enhancement of biodegradability and bioactivity. Gelatin coated scaffolds also demonstrated improved cell viability and adhesion and over two times higher expression of OPN and ALP genes, suggesting improved biological properties. In addition, in vivo bone formation studies verified the biological enhancement of scaffolds. Utilizing an immobilized crosslinked gelatin biomacromolecule coating effectively enhanced the biological characteristics of 3D printed scaffolds and their potential applications as bone tissue engineering scaffolds.

Effect of mechanical instrumentation on titanium implant surface properties.

To assess the impact of mechanical decontamination using rotary brushes on the surface topography, elemental composition, roughness, and wettability of titanium implant surfaces. Four commercially available rotary brushes were used: Labrida BioClean Brush® (LB), i-Brush1 (IB), NiTiBrush Nano (NiTiB), and Peri-implantitis Brush (PIB). Seventy-five titanium discs with sandblasted, large-grit, acid-etched (SLA) surfaces were randomly assigned to five groups (n = 15): LB, IB, NiTiB, PIB, and a control group. Each disc was treated for 60 seconds with the respective rotary brush according to the manufacturer's instructions. Surface morphology was analysed using Scanning Electron Microscopy (SEM), surface elemental composition with Energy Dispersive X-ray (EDX), surface roughness via optical profilometry, and wettability with a droplet shape analyser. SEI analysis revealed morphological changes, including scratches, flattening, and loose titanium particles in the IB, PIB, and NiTiB groups, whereas the LB group preserved the original surface morphology. SEM-EDX analysis showed that LB, PIB, and NiTiB groups closely match the control elemental composition. However, IB groups showed significantly different composition. Surface roughness values in the IB, PIB, and NiTiB groups differed significantly from the control (p < 0.05), whereas the LB group had comparable roughness values (p > 0.05). Contact angle measurements indicated enhanced wettability in IB, PIB, and NiTiB groups (p < 0.05), while the LB group exhibited values comparable to the control (p > 0.05). Mechanical decontamination of implant surfaces utilising rotary brushes can alter implant surface properties.