Establishment of an Animal Model of Dog Bite Injuries.

Nowadays dog bite is becoming a world public health problem. Therefore, the study aimed to develop a dog bite animal model that is helpful to solve these problems. In this study, the skull of an adult dog was scanned. The three-dimensional model of the dog maxillofacial bones and dentition was built by MIMICS. Next, the model was printed with Co-Cr alloy by using selective laser sintering technology to develop the dog bite simulation pliers. Then, to simulate dog bite to most, the maximum bite force of the pliers was measured and actions contained in dog bite process was analyzed. Afterwards, according to action analysis results, rabbits were bitten by the prepared instrument in actions that simulate dog's bite. Finally, the reproducibility and controllability of this animal model of dog bite injuries was validated in an in vivo study. The results showed a reliable animal model of dog bite injuries has been developed in this study. The sites and severities of the injuries could be adjusted as the operator wishes and the animal model of dog bite injuries was highly repeatable. This study also indicates the feasibility of using digital technology in establishing animal bite models.

Using the Photo-Piezoelectric Effect of AuPt@BaTiO3 Oxidase Mimetics for Colorimetric Detection of GSH in Serum.

Nanozymes possess major advantages in catalysis and biosensing compared with natural nanozymes. In this study, the AuPt@BaTiO3 bimetallic alloy Schottky junction is prepared to act as oxidase mimetics, and its photo-piezoelectric effect is investigated. The synergy between the photo-piezoelectric effect and the local surface plasmon resonance enhances the directional migration and separation of photogenerated electrons, as well as hot electrons induced by the AuPt bimetallic alloy. This synergy significantly improves the oxidase-like activity. A GSH colorimetric detection platform is developed based on this fading principle. Leveraging the photo-piezoelectric effect allows for highly sensitive detection with a low detection limit (0.225 µM) and reduces the detection time from 10 min to 3 min. The high recovery rate (ranging from 99.91% to 101.8%) in actual serum detection suggests promising potential for practical applications. The development of bimetallic alloy heterojunctions presents new opportunities for creating efficient nanozymes.

Aqueous Synthesis of Plasmonic Gold-Tin Alloy Nanoparticles.

This protocol describes the synthesis of Au nanoparticle seeds and the subsequent formation of Au-Sn bimetallic nanoparticles. These nanoparticles have potential applications in catalysis, optoelectronics, imaging, and drug delivery. Previously, methods for producing alloy nanoparticles have been time-consuming, require complex reaction conditions, and can have inconsistent results. The outlined protocol first describes the synthesis of approximately 13 nm Au nanoparticle seeds using the Turkevich method. The protocol next describes the reduction of Sn and its incorporation into the Au seeds to generate Au-Sn alloy nanoparticles. The optical and structural characterization of these nanoparticles is described. Optically, prominent localized surface plasmon resonances (LSPRs) are apparent using UV-visible spectroscopy. Structurally, powder X-ray diffraction (XRD) reflects all particles to be less than 20 nm and shows patterns for Au, Sn, and multiple Au-Sn intermetallic phases. Spherical morphology and size distribution are obtained from transmission electron microscopy (TEM) imaging. TEM reveals that after Sn incorporation, the nanoparticles grow to approximately 15 nm in diameter.

Surface modification of a commercial bone plate (Ti6Al4V) implant for improved antibacterial and cytocompatibility via thermal dewetting of a silver thin film.

The high demand for bone grafts has motivated the development of implants with excellent osteogenic activity, whereas the risk of implant-associated infection, particularly given the rise of antimicrobial resistance, has compelled the development of implants with innovative antimicrobial strategies in which a small amount of bactericidal agent can effectively kill a wide range of bacteria. To induce antibacterial property, the surface of Grade-5 bone plate titanium implants used in clinical applications was modified using direct current (DC) sputter coating followed by thermal annealing. The 15 nm silver film-coated implants were thermally annealed in the furnace for 15 min at 750 °C. The modified implant surface's antibacterial efficacy againstEscherichia coli(E. coli),Staphylococcus aureus(S. aureus),Salmonella typhi, andMethicillin-resistant staphylococcus aureusbacteria has been assessed using a colony-forming assay. On the modified implant surface, the growth ofE. coliandS. aureusbacteria is reduced by 99.72%, while highly drug-resistant bacteria are inhibited by 96.59%. The MTT assay was used to assess the cytotoxicity of the modified bone-implant surface against NIH3T3 mouse fibroblast cells. The modified bone-implant surface promoted fibroblast growth and demonstrated good cytocompatibility. Furthermore, the mechanical properties of the implant were not harmed by this novel surface modification method. This method is simple and provides new insight into surface modification of commercial metallic implants to have effective antibacterial properties against various classes of bacteria.

The Influence of Contamination and Different Cleaning Methods and the Effect of Plasma Treatment of CoCr Alloy on Tensile Bond Strength to Composite Resin.

PURPOSE: To investigate the influence of contamination and different cleaning methods on resin bonding to cobalt-chro- mium (CoCr) alloy disks. MATERIALS AND METHODS: A total of 160 CoCr disks were divided into 3 groups. The first group (N = 64) was air abraded with alumina particles and contaminated with a silicone disclosing agent and saliva; the second group (N = 64) was air abraded but not contaminated; the third group (N = 32) was neither air abraded nor contaminated. The first two groups were di- vided into 4 subgroups (N = 16) according to the cleaning method: ultrasonic bath in 99% isopropanol, use of a cleaning suspension of zirconium oxide particles, use of a cleaning suspension based on 10-MDP salt, and treatment with atmo- spheric plasma. The third group was divided into 2 subgroups (N = 16): treatment with atmospheric plasma and no treat- ment. All CoCr specimens were bonded to plexiglas tubes filled with a bonding resin that contained phosphate monomer. Tensile bond strength (TBS) was examined by tensile testing after 3 and 150 days of water storage plus 37,500 thermal cy- cles (N = 8). RESULTS: After contamination, TBS was significantly reduced after 150 days of water storage. Groups without air abrasion showed initially low TBS and debonded spontaneously after 150 days of water storage. CONCLUSION: None of the cleaning methods was able to remove saliva and silicone disclosing agent on CoCr-alloy sur- faces. Surface activation by plasma treatment has no long-term effect on the bond strength.

Employing Piper longum extract for eco-friendly fabrication of PtPd alloy nanoclusters: advancing electrolytic performance of formic acid and methanol oxidation.

Advancement in bioinspired alloy nanomaterials has a crucial impact on fuel cell applications. Here, we report the synthesis of PtPd alloy nanoclusters via the hydrothermal method using Piper longum extract, representing a novel and environmentally friendly approach. Physicochemical characteristics of the synthesized nanoclusters were investigated using various instrumentation techniques, including X-ray photoelectron spectroscopy, X-ray diffraction, and High-Resolution Transmission electron microscopy. The electrocatalytic activity of the biogenic PtPd nanoclusters towards the oxidation of formic acid and methanol was evaluated chronoamperometry and cyclic voltammetry studies. The surface area of the electrocatalyst was determined to be 36.6 m2g-1 by Electrochemical Surface Area (ECSA) analysis. The biologically inspired PtPd alloy nanoclusters exhibited significantly higher electrocatalytic activity compared to commercial Pt/C, with specific current responses of 0.24 mA cm - 2 and 0.17 mA cm - 2 at synthesis temperatures of 180 °C and 200 °C, respectively, representing approximately four times higher oxidation current after 120 min. This innovative synthesis approach offers a promising pathway for the development of PtPd alloy nanoclusters with enhanced electrocatalytic activity, thereby advancing fuel cell technology towards a sustainable energy solution.

Heating of metallic orthodontic devices during anti-aging treatment with vacuum and electromagnetic fields: In vitro study.

BACKGROUND: The physical appearance of an individual plays a primary role as it influences the opinion of the viewer. For this reason, orthodontic therapy to improve perceived aesthetics is in high demand among patients. This factor, combined with the increase in the number of non-invasive facial aesthetic treatments, has led to the need to understand potential risk factors in the application of medical devices to the perioral skin in patients with fixed orthodontic appliances. The aim of this study was to evaluate in vitro heating of the orthodontic bracket following electromagnetic fields and negative pressure (V-EMF) used as an anti-aging treatment. METHODS: Two different types of titanium alloy wires, one made of "beta-Titanium" alloy and the other "Ni-Ti" (DW Lingual Systems GmbH-Bad Essen-Germany) were used. The orthodontic wires and brackets mounted on a resin mouth were covered with porcine muscle tissue, then subjected to anti-aging therapy with a Bi-one LifeTouchTherapy medical device (Expo Italia Srl-Florence-Italy) which generates a combination of vacuum and electromagnetic fields (V-EMF) already adopted for antiaging therapy. During administration of the therapy, the orthodontic brackets and porcine tissue were thermally monitored using a Wavetek Materman TMD90 thermal probe (Willtek Communications GmbH-Germany). In total 20 orthodontic mouths were used, 10 with Beta Titanium wires and 10 with Nickel Titanium wires. RESULTS: A temperature increase of about 1°C was recorded in each group. The outcome of the present research shows that the absolute temperatures measured on orthodontic appliances, which, despite having a slightly different curve, both show an increase in temperature of 1.1°C at the end of the session, thus falling well within the safety range of 2°C as specified by the standard CENELEC EN 45502-1. Therefore, V-EMF therapy can be considered safe for the entire dental system and for metal prostheses, which tend to heat up at most as much as biological tissue (+0.9°C/1.1°C vs. 1.1°C/1.1°C). CONCLUSION: In conclusion, anti-aging therapy with V-EMF causes a thermal increase on orthodontic brackets that is not harmful to pulp health.

Microcomputed tomography analysis of curved root canal preparation when coronal flaring and glide path files used with heat-treated nickel titanium rotary files.

The objective was to evaluate the effect of glide path and coronal flaring on the dentin volume removal and percentage of touched walls in curved canals using two heat-treated rotary files. The mesiobuccal canal of forty-eight, randomly selected, extracted mandibular molars was divided into two groups of 24 each, according to the type of instrument used (RACE EVO and EdgeSequel rotary files). Each group was further divided into three subgroups; Group (A): Control using one file shaped to 04/30, Group (B) with a glide path (EdgeGlidePath (EGP)), and Group (C): with a glide path and coronal flaring (EGP and EdgeTaper Platinum (ETP) SX file respectively). The root canals were then instrumented using the assigned instruments. The assessment was carried out using micro-CT. The comparison of the mean values of the tested groups about dentin volume removal and percentage of untouched walls did not reach statistical significance (p<0.05). Glide path and coronal flaring had an insignificant effect on the dentin volume removal and percentage of untouched walls in curved canals.

An efficient method of preparing Si-Fe-Al-Ca alloy from coal gasification fine slag via plasma smelting and alternating current magnetic field.

It is of great significance to solve the environmental problems caused by the unreasonable treatment of coal gasification slag. This study successfully produced Si-Fe-Al-Ca alloy from low-carbon fine slag with petroleum coke as reducing agent in a plasma furnace with an alternating current magnetic field, which solved the problem of the high reactivity requirement of carbon reductant for plasma smelting. The optimum carbon content of the mixed low-carbon fine slag and petroleum coke is 105% of the theoretical value. As the strength of the alternating current magnetic field increased (from 0% to 100% of the maximum power), the yield of the alloy (from 25.46% to 58.19%) and the recovery ratios of each element (Si, Fe, Al, Ca, Ti) increased. In addition, as the magnetic field strength increased, the pores inside the alloy became smaller, the composition of the alloy became more homogeneous, and a better separation of the alloy from the slag was observed. The main composition of the alloy at the strongest alternating current magnetic field is Si: 51.14 wt%, Fe: 28.41 wt%, Al: 9.14 wt%, Ca: 7.15 wt%, Ti: 2.03 wt%. We attribute the enhanced smelting effect of the alternating current magnetic field to the resistive heat and Lorentz force produced by the induced current. In addition, the skin effect concentrated the induced current on the surface of the oxide particles and carbon particles, which increased the temperature of the reaction interface and promoted the carbothermal reduction reaction.

Corrosion and Biological Behaviors of Biomedical Ti-24Nb-4Zr-8Sn Alloy under an Oxidative Stress Microenvironment.

Biomaterials can induce an inflammatory response in surrounding tissues after implantation, generating and releasing reactive oxygen species (ROS), such as hydrogen peroxide (H2O2). The excessive accumulation of ROS may create a microenvironment with high levels of oxidative stress (OS), which subsequently accelerates the degradation of the passive film on the surface of titanium (Ti) alloys and affects their biological activity. The immunomodulatory role of macrophages in biomaterial osteogenesis under OS is unknown. This study aimed to explore the corrosion behavior and bone formation of Ti implants under an OS microenvironment. In this study, the corrosion resistance and osteoinduction capabilities in normal and OS conditions of the Ti-24Nb-4Zr-8Sn (wt %, Ti2448) were assessed. Electrochemical impedance spectroscopy analysis indicated that the Ti2448 alloy exhibited superior corrosion resistance on exposure to excessive ROS compared to the Ti-6Al-4V (TC4) alloy. This can be attributed to the formation of the TiO2 and Nb2O5 passive films, which mitigated the adverse effects of OS. In vitro MC3T3-E1 cell experiments revealed that the Ti2448 alloy exhibited good biocompatibility in the OS microenvironment, whereas the osteogenic differentiation level was comparable to that of the TC4 alloy. The Ti2448 alloy significantly alleviates intercellular ROS levels, inducing a higher proportion of M2 phenotypes (52.7%) under OS. Ti2448 alloy significantly promoted the expression of the anti-inflammatory cytokine, interleukin 10 (IL-10), and osteoblast-related cytokines, bone morphogenetic protein 2 (BMP-2), which relatively increased by 26.9 and 31.4%, respectively, compared to TC4 alloy. The Ti2448 alloy provides a favorable osteoimmune environment and significantly promotes the proliferation and differentiation of osteoblasts in vitro compared to the TC4 alloy. Ultimately, the Ti2448 alloy demonstrated excellent corrosion resistance and immunomodulatory properties in an OS microenvironment, providing valuable insights into potential clinical applications as implants to repair bone tissue defects.

Data analysis of the influence of microstructure, composition, and loading conditions on stress corrosion cracking behavior of Mg alloys.

Stress corrosion cracking (SCC) can be a crucial problem in applying rare earth (RE) Magnesium alloys in environments where mechanical loads and electrochemical driven degradation processes interact. It has been proven already that the SCC behavior is associated with microstructural features, compositions, loading conditions, and corrosive media, especially in-vivo. However, it is still unclear when and how mechanisms acting on multiple scales and respective system descriptors predictable contribute to SCC for the wide set of existing Mg alloys. In the present work, suitable literature data along SCC of Mg alloys has been analyzed to enable the development of a reliable SCC model for MgGd binary alloys. Pearson correlation coefficient and linear fitting are utilized to describe the contribution of selected parameters to corrosion and mechanical properties. Based on our data analysis, a parameter ranking is obtained, providing information on the SCC impact with regard to ultimate tensile strength (UTS) and fracture elongation of respective materials. According to the analyzed data, SCC susceptibility can be grouped and mapped onto Ashby type diagrams for UTS and elongation of respective base materials tested in air and in corrosive media. The analysis reveals the effect of secondary phase content as a crucial materials descriptor for our analyzed materials and enables better understanding towards SCC model development for Mg-5Gd alloy based implant.

A cutting tool architecture designed to address the parasitic mechanisms consuming excess power during machining and manufacturing operations-A review-based study towards sustainable manufacturing.

Metal cutting has been extensively studied over the years for improving its efficacy, yet, parasitic mechanisms like chatter and tool wear continue to generate higher forces and energy consumption with poor surface integrity. To address these parasitic mechanisms, a single-point turning cutter design is proposed based on the physics-of-machining including chatter theory to achieve reduced power consumption during the cutting of various metallic alloys like Al-6061, Ti-6Al-4V and others used by critical sectors such as aerospace and automotive. The current work focuses on aspects of machining that effectively reduce parasitic forces feeding into cutting power. The proposed cutter amalgamates features such as optimum side and end cutting edge angles, smaller nose radius and textured rake face into the cutter-body. Such a design is further proposed for use with a mechanochemical effect on a recently discovered plastic flow mode called sinuous flow, which has been reported to bring down cutting forces significantly. Experimental and analytical tests on the cutter design features validate reduction of cutting forces and through that alleviate the tendency to chatter as well as bring about energy savings for cutting of Al 6061. The potential for reduced real-time power consumption makes this design-framework significant for multipoint milling cutters too. It will greatly facilitate frugal manufacturing to account for sustainability in manufacturing operations.

In vivo evaluation of safety and performance of a tapered nitinol venous stent with inclined proximal end in an ovine iliac venous model.

A tapered stent with inclined proximal end is designed for fitting the iliac anatomically. The aim of the present study was to evaluate the safety and performance of the new stent in ovine left iliac veins. The experiment was performed in 30 adult sheep, and one nitinol-based VENA-BT® iliac venous stent (KYD stent) was implanted into each animal's left common iliac vein. Follow-up in all sheep consisted of angiographic, macroscopic, and microscopic examinations at Day 0 (< 24 h), Day 30, Day 90, Day 180 and Day 360 post-stenting (six animals per each time-point). 30 healthy ~ 50 kg sheep were included in this study and randomly divided into five groups according to the follow-up timepoint. All stents were implanted successfully into the left ovine common iliac vein. No significant migration occurred at follow-up. There is no statistically significant difference between the groups (p > 0.05), indicating no serious lumen loss occurred during the follow-up period. Common iliac venous pressure was further measured and the results further indicated the lumen patency at follow-up. Histological examinations indicated that no vessel injury and wall rupture, stent damage, and luminal thrombus occurred. There was moderate inflammatory cell infiltration around the stent in Day-0 and Day-30 groups with the average inflammation score of 2.278 and 2.167, respectively. The inflammatory reaction was significantly reduced in Day-90, Day-180 and Day-360 groups and the average inflammation scores were 0.9444 (p < 0.001, Day-90 vs Day-0), 1.167 (p < 0.001, Day-180 vs Day-0) and 0.667 (p < 0.001, Day-90 vs Day-0), respectively. The microscopic examinations found that the stents were well covered by endothelial cells in all follow-up time points. The results suggested that the KYD stent is feasible and safe in animal model. Future clinical studies may be required to further evaluate its safety and efficacy.

In vivo validation of highly customized cranial Ti-6AL-4V ELI prostheses fabricated through incremental forming and superplastic forming: an ovine model study.

Cranial reconstructions are essential for restoring both function and aesthetics in patients with craniofacial deformities or traumatic injuries. Titanium prostheses have gained popularity due to their biocompatibility, strength, and corrosion resistance. The use of Superplastic Forming (SPF) and Single Point Incremental Forming (SPIF) techniques to create titanium prostheses, specifically designed for cranial reconstructions was investigated in an ovine model through microtomographic and histomorphometric analyses. The results obtained from the explanted specimens revealed significant variations in bone volume, trabecular thickness, spacing, and number across different regions of interest (VOIs or ROIs). Those regions next to the center of the cranial defect exhibited the most immature bone, characterized by higher porosity, decreased trabecular thickness, and wider trabecular spacing. Dynamic histomorphometry demonstrated differences in the mineralizing surface to bone surface ratio (MS/BS) and mineral apposition rate (MAR) depending on the timing of fluorochrome administration. A layer of connective tissue separated the prosthesis and the bone tissue. Overall, the study provided validation for the use of cranial prostheses made using SPF and SPIF techniques, offering insights into the processes of bone formation and remodeling in the implanted ovine model.

Lipid changes and molecular mechanism inducing cuproptosis in Cryptocaryon irritans after copper-zinc alloy exposure.

Cryptocaryons irritans is a ciliate parasite responsible for cryptocaryoniasis, leading to considerable economic losses in aquaculture. It is typically managed using a copper-zinc alloy (CZA), effectively diminishing C. irritans infection rates while ensuring the safety of aquatic organisms. Nevertheless, the precise mechanism underlying cuproptosis induced C. irritans mortality following exposure to CZA remains enigmatic. Therefore, this study delves into assessing the efficacy of CZA, investigate cuproptosis as a potential mechanism of CZA action against C. irritans, and determine the alterations in antioxidant enzymes, peroxidation, and lipid metabolism. The mRNA expression of dihydrolipoamide S-acetyltransferase was upregulated after 40 and 70 min, while aconitase 1 was implicated in cuproptosis following 70 min of CZA exposure. Furthermore, the relative mRNA levels of glutathione reductase experienced a significant increase after 40 and 70 min of CZA exposure. In contrast, the relative mRNA levels of glutathione S-transferase and phospholipid-hydroperoxide glutathione peroxidase were significantly decreased after 70 min, suggesting a disruption in antioxidant defense and an imbalance in copper ions. Lipidomics results also unveiled an elevation in glycerophospholipids metabolism and the involvement of the lipoic acid pathway, predominantly contributing to cuproptosis. In summary, exposure to CZA induces cuproptosis in C. irritans, impacts glutathione-related enzymes, and alters glycerophospholipids, consequently triggering lipid oxidation.

Surface modification of additive manufactured Ti6Al4V scaffolds with gelatin/alginate- IGF-1 carrier: An effective approach for healing bone defects.

The study investigates the potential of porous scaffolds with Gel/Alg-IGF-1 coatings as a viable candidate for orthopaedic implants. The scaffolds are composed of additively manufactured Ti6Al4V lattices, which were treated in an alkali solution to obtain the anatase and rutile phases. The treated surface exhibited hydrophilicity of <11.5°. A biopolymer carrier containing Insulin-like growth factor 1 was coated on the samples using immersion treatment. This study showed that the surface-modified porous Ti6Al4V scaffolds increased cell viability and proliferation, indicating potential for bone regeneration. The results demonstrate that surface modifications can enhance the osteoconduction and osteoinduction of Ti6Al4V implants, leading to improved bone regeneration and faster recovery. The porous Ti6Al4V scaffolds modified with surface coating of Gel/Alg-IGF-1 exhibited a noteworthy increase in cell viability (from 80.7 to 104.1%viability) and proliferation. These results suggest that the surface modified scaffolds have potential for use in treating bone defects.

Fixation technique of biodegradable magnesium alloy suture anchor in the rotator cuff repair of the shoulder in a goat model: a technical note.

BACKGROUND: Shoulder disorders, particularly rotator cuff tears, are prevalent musculoskeletal conditions related to aging. Although the widely used suture anchor technique provides strong mechanical support to the tendon, it is associated with a risk of postoperative tendon retearing. The conventionally used titanium alloys can affect the interpretation of magnetic resonance imaging. Degradable magnesium alloys possess excellent biocompatibility, similar mechanical property to the bone, and stimulating bone formation ability from Mg2+. The purpose of this experiment was to develop innovative magnesium-based suture anchors to enhance rotator cuff repair by improving fixation materials, and to evaluate their feasibility in a goat model. METHODS: We developed fluoridized ZK60 suture anchors as the implantation material for two goats, who underwent rotator cuff repair surgery on both shoulders. Computed tomography (CT) and histological analysis were performed at 12 weeks postoperatively, and the results were compared between the magnesium and titanium alloy groups. Additionally, a hematological examination was conducted, which included assessments of red blood cells, white blood cells, platelets, coagulation function, liver function, kidney function, and magnesium ion concentration. RESULTS: The 12-week postoperative CT images showed intact MgF2 ZK60 suture anchors, effectively reconnecting the infraspinatus tendon to the humeral head. The anchors became less visible on CT scans, indicating absorption by surrounding tissues. New bone formation in the MgF2 group surpassed that in the Ti group, demonstrating superior osseointegration. The similarity between cortical bone and magnesium reduced stress-shielding and promoted bone regeneration. Histological analysis revealed successful tendon healing with MgF2 anchors, while the Ti group showed discontinuous interfaces and reduced collagen secretion. Hematological examination showed stable liver, renal function, and magnesium ion levels. CONCLUSIONS: The findings indicate that MgF2-coated suture anchors are feasible for rotator cuff repair and potentially other orthopedic applications. We hope that magnesium alloy anchors can become the solution for rotator cuff tendon repair surgery.

In Vitro Assessment of the Neuro-Compatibility of Fe-20Mn as a Potential Bioresorbable Material for Craniofacial Surgery.

Background and Objectives: Spring-assisted surgery is a popular option for the treatment of non-syndromic craniosynostosis. The main drawback of this procedure is the need for a second surgery for spring removal, which could be avoided if a distractor material could be metabolised over time. Iron-Manganese alloys (FeMn) have a good trade-off between degradation rate and strength; however, their biocompatibility is still debated. Materials and Methods: In this study, the neuro-compatibility of Fe-20Mn (wt.%) was assessed using standard assays. PC-12 cells were exposed to Fe-20Mn (wt.%) and stainless steel via indirect contact. To examine the cytotoxicity, a Cell Tox Green assay was carried out after 1, 2, and 3 days of incubation. Following differentiation, a neurite morphological examination after 1 and 7 days of incubation time was carried out. The degradation response in modified Hank's solution at 1, 3, and 7 days was investigated, too. Results: The cytotoxicity assay showed a higher toxicity of Fe-20Mn than stainless steel at earlier time points; however, at the latest time point, no differences were found. Neurite morphology was similar for cells exposed to Fe-20Mn and stainless steel. Conclusions: In conclusion, the Fe-20Mn alloy shows promising neuro-compatibility. Future studies will focus on in vivo studies to confirm the cellular response to Fe-20Mn.

Biocompatibility and Osseointegration of the Biomimetically Coated and Water-Soluble Eggshell Membrane Protein Cross-Linked Ti Alloy Screws.

Background: The surface properties of dental and orthopedic implants are directly related to their osseointegration rate. Coating and/or modifying the implant surface might reduce the time of healing. In this study, we aimed to examine the effects of a hybrid surface consisting of a brushite surface coating and cross-linked water-soluble eggshell membrane protein on the osseointegration of titanium (Ti) screws under in vivo conditions. Methods: Twenty Ti alloy screws were implanted monocortically in anteromedial regions of New Zealand rabbit tibiae. Ten screws were untreated and used as controls. The remaining 10 screws were coated with calcium phosphate and following cross-linked with ostrich eggshell membrane protein. All rabbits were sacrificed six weeks after the surgery. Peri-screw tissues were evaluated by micro-computed tomography (µ-CT), histological and histomorphometrical methods. Results: The µ-CT assessments indicated that the experimental group had significantly higher mean bone surface area (BSA) and trabeculae number (TbN) than those of the control group (p ˂ 0.05). Bone surface area (BV), trabecular separation (TbSp), trabecular thickness (TbTh), and bone mineral density (BMD) scores of the control and experimental groups were quite similar (p > 0.05). The vascularization score of the experimental group was significantly higher than the control group (4.29 vs. 0.92%). No sign of the graft-versus-host reaction was observed. Conclusion: Our findings reveal that coating Ti alloy implants with calcium phosphate cross-linked with ostrich eggshell membrane protein increases the osseointegration of Ti alloy screws by increasing the bone surface area, number of trabeculae and vascularization in the implant site.

Surface Modification of Zn-Cu Alloy with Heparin Nanoparticles for Urinary Implant Applications.

In this work, an investigation on the Zn-Cu alloy coated with heparin was conducted in order to explore the potentiality of its application as a feasible alternative for biodegradable implants, with the specific goal of addressing the issue of encrustation in the urinary system. The stability of the nanoparticles were characterized by dynamic light scattering. Typical surface characterization such as X-ray photoelectron spectroscopy, scanning electron microscopy, and atomic force microscopy were used to demonstrate a successful immobilization of the NPs. The in vitro corrosion behavior was studied by potentiodynamic polarization and immersion tests in artificial urine (AU) at 37 °C. The 8 weeks in vivo degradation, encrustation resistance, hemocompatibility, and histocompatibility were investigated by means of implantation into the bladders of rats. Both in vitro and in vivo degradation tests exhibited a higher degradation rate for Zn-Cu and NPs groups when compared to pure Zn. Histological evaluations and hemocompatibility revealed that there was no tissue damage or pathological alterations caused by the degradation process. Furthermore, antiencrustation performance and urinalysis results confirmed that the modified alloy demonstrated significant encrustation inhibitory properties and bactericidal activity compared to the pure Zn control. Our findings highlight the potential of this modified alloy as an antiencrustation biodegradable ureteral stent.