Plasma Immersion Ion Implantation Technique Research Articles

A Preclinical Trial Protocol Using an Ovine Model to Assess Scaffold Implant Biomaterials for Repair of Critical-Sized Mandibular Defects.

The present work describes a preclinical trial (in silico, in vivo and in vitro) protocol to assess the biomechanical performance and osteogenic capability of 3D-printed polymeric scaffolds implants used to repair partial defects in a sheep mandible. The protocol spans multiple steps of the medical device development pipeline, including initial concept design of the scaffold implant, digital twin in silico finite element modeling, manufacturing of the device prototype, in vivo device implantation, and in vitro laboratory mechanical testing. First, a patient-specific one-body scaffold implant used for reconstructing a critical-sized defect along the lower border of the sheep mandible ramus was designed using on computed-tomographic (CT) imagery and computer-aided design software. Next, the biomechanical performance of the implant was predicted numerically by simulating physiological load conditions in a digital twin in silico finite element model of the sheep mandible. This allowed for possible redesigning of the implant prior to commencing in vivo experimentation. Then, two types of polymeric biomaterials were used to manufacture the mandibular scaffold implants: poly ether ether ketone (PEEK) and poly ether ketone (PEK) printed with fused deposition modeling (FDM) and selective laser sintering (SLS), respectively. Then, after being implanted for 13 weeks in vivo, the implant and surrounding bone tissue was harvested and microCT scanned to visualize and quantify neo-tissue formation in the porous space of the scaffold. Finally, the implant and local bone tissue was assessed by in vitro laboratory mechanical testing to quantify the osteointegration. The protocol consists of six component procedures: (i) scaffold design and finite element analysis to predict its biomechanical response, (ii) scaffold fabrication with FDM and SLS 3D printing, (iii) surface treatment of the scaffold with plasma immersion ion implantation (PIII) techniques, (iv) ovine mandibular implantation, (v) postoperative sheep recovery, euthanasia, and harvesting of the scaffold and surrounding host bone, microCT scanning, and (vi) in vitro laboratory mechanical tests of the harvested scaffolds. The results of microCT imagery and 3-point mechanical bend testing demonstrate that PIII-SLS-PEK is a promising biomaterial for the manufacturing of scaffold implants to enhance the bone-scaffold contact and bone ingrowth in porous scaffold implants. MicroCT images of the harvested implant and surrounding bone tissue showed encouraging new bone growth at the scaffold-bone interface and inside the porous network of the lattice structure of the SLS-PEK scaffolds.

Identification of Expanded Austenite in Nitrogen-Implanted Ferritic Steel through In Situ Synchrotron X-ray Diffraction Analyses

The existence and formation of expanded austenite in ferritic stainless steels remains a subject of debate. This research article aims to provide comprehensive insights into the formation and decomposition of expanded austenite through in situ structure analyses during thermal treatments of ferritic steels. To achieve this objective, we employed the Plasma Immersion Ion Implantation (PIII) technique for nitriding in conjunction with in situ synchrotron X-ray diffraction (ISS-XRD) for microstructural analyses during the thermal treatment of the samples. The PIII was carried out at a low temperature (300–400 °C) to promote the formation of metastable phases. The ISS-XRD analyses were carried out at 450 °C, which is in the working temperature range of the ferritic steel UNS S44400, which has applications, for instance, in the coating of petroleum distillation towers. Nitrogen-expanded ferrite (αN) and nitrogen-expanded austenite (γN) metastable phases were formed by nitriding in the modified layers. The production of the αN or γN phase in a ferritic matrix during nitriding has a direct relationship with the nitrogen concentration attained on the treated surfaces, which depends on the ion fluence imposed during the PIII treatment. During the thermal evolution of crystallographic phase analyses by ISS-XRD, after nitriding, structure evolution occurs mainly by nitrogen diffusion. In the nitrided samples prepared under the highest ion fluences—longer treatment times and frequencies (PIII 300 °C 6 h and PIII 400 °C 3 h) containing a significant amount of γN—a transition from the γN phase to the α and CrN phases and the formation of oxides occurred.

Manganese-Implanted Titanium Modulates the Crosstalk between Bone Marrow Mesenchymal Stem Cells and Macrophages to Improve Osteogenesis.

Manganese (Mn) is an essential micronutrient in various physiological processes, but its functions in bone metabolism remain undefined. This is partly due to the interplay between immune and bone cells because Mn plays a central role in the immune system. In this study, we utilized the plasma immersion ion implantation and deposition (PIII&D) technique to introduce Mn onto the titanium surface. The results demonstrated that Mn-implanted surfaces stimulated the shift of macrophages toward the M1 phenotype and had minimal effects on the osteogenic differentiation of mouse bone marrow mesenchymal stem cells (mBMSCs) under mono-culture conditions. However, they promoted the M2 polarization of macrophages and improved the osteogenic activities of mBMSCs under co-culture conditions, indicating the importance of the crosstalk between mBMSCs and macrophages mediated by Mn in osteogenic activities. This study provides a positive incentive for the application of Mn in the field of osteoimmunology.

Effect of plasma immersion ion implantation on wear behavior of Ti-6Al-4V alloy

Ti-6Al-4V alloy is ideal for use in the aeronautical and aerospace industries because of its excellent strength/weight ratio and corrosion resistance. However, its applications at high temperatures are vulnerable due to its high affinity for interstitial elements, such as nitrogen and oxygen. The plasma immersion ion implantation (PIII) technique, performed at high temperature, allows formation of modified layers that can improve the mechanical and tribological properties without compromising the corrosion resistance, which is a characteristic of this alloy. In this work, the samples were treated by PIII at three different temperatures (700, 800, and 900 °C) for 120 min of exposure to evaluate PIII on the mechanical behavior of Ti-6Al-4V alloy compared to data already available in the literature. The aim of this process is to improve surface mechanical properties of the Ti-6Al-4V alloy. The techniques used in this work were x-ray diffraction microhardness, glow discharge optical emission spectrometer, and wear testing in a ball-on-disk tribometer. The results indicate a significantly increased material resistance, with a reduced wear for all treated samples and a reduced friction coefficient for samples treated at 800 and 900 °C. The best results were for alloy treated at 800 and 900 °C, because they maintain the low coefficient throughout the test, which indicates better wear resistance.

Improved In Vitro and In Vivo Corrosion Resistance of Mg and Mg Alloys by Plasma Ion Implantation and Deposition Techniques—A Mini-Review

Enhanced in vitro corrosion resistance, cytocompatibility, in vitro antibacterial activities, in vivo antibacterial activities, in vivo corrosion resistance and in vivo stimulation of bone formation on plasma-modified biodegradable Mg and its alloys are reviewed, where the plasma modification includes plasma ion implantation (PII), plasma immersion ion implantation (PIII), or plasma immersion ion implantation and deposition (PIII&D) techniques. PII, PIII, and PIII&D are useful surface modification techniques, which can alter the surface properties of the biomaterials while preventing the bulk properties, which is much desirable factor especially for Mg based biomaterials. At first, this paper reviews the improved corrosion resistance by the formation of protective passive surface layer containing Zr-O, Zr-N, N, Si, Al-O, Zn-Al, Cr-O, Ti-O, Ti-N, Fe, Y, Sr, P, Pr, Ce, Nd, Hf, Ta, or C on Mg or its alloys using PII, PIII, or PIII&D techniques. Then, this paper reviews the improved biological properties such as cytocompatibility, in vitro antibacterial activities, and in vivo antibacterial activities on plasma-modified Mg or its alloys. Finally, this paper reviews the improved in vivo corrosion resistance and in vivo stimulation of bone formation on plasma modified Mg alloys. This review suggests that PII, PIII, and PIII&D techniques are effective techniques to improve the in vitro and in vivo corrosion resistance of Mg and its alloys for the development of degradable bio-implants.

The influence of plasma nitriding hardness treatment on the dynamic compressive behavior of the Hardox 400 at a wide temperature range

This paper aims to study the effect of hardness nitriding treatment on the overall mechanical behavior of Hardox 400 steel. A Plasma Immersion Ion Implantation (PIII) technique was used for material nitriding while a split Hopkinson pressure bar equipped with an electromagnetic heating system was used for the thermomechanical characterization of the studied steel. The collected data are analyzed to identify the combined effect of the high strain rates and elevated temperatures on the flow stress and ductility. The microstructure and the physical properties of the nitrided Hardox 400 were studied using scanning electron microscopy (SEM), X-ray diffraction, and nano-indentation tests. Although the increase of the surface hardness by 37%, the quasistatic and dynamic compression tests showed a decrease in the flow stress due to the microstructure modification caused by the increase of the temperature during the plasma nitriding process. For a better assessment of the experimental results, reduction factors for the main mechanical properties are reported. The test data from SHPB indicated a dependency of the strain rate to the temperature of untreated un-nitrided Hardox 400. Finally, a critical review of the well-known Johnson-Cook constitutive model is highlighted, where material parameters are calibrated with special attention to the thermal softening parameter. The obtained results could be of great interest for the assessment of structural components’ robustness where the combined strain rate and temperature for Hardox 400 are met.

High quality low thermal budget low cost SiO2 film fabricated by O2 plasma immersion ion implantation

O2 plasma immersion ion implantation technique has been developed to form high quality low thermal budget low cost SiO2 films with unique feature of selective oxidation for three-dimensional or nonplanar structures of ultra-large-scale integration applications. The formed SiO2 material was extensively characterized and investigated. The SiO2 films have demonstrated good chemical stoichiometric composition, and good electrical properties including higher bulk resistivity ρ, higher breakdown charge QBD, comparable dielectric constant k and interface state density Dit. The formed SiO2 material has demonstrated better qualities than those of tetraethyl orthosilicate SiO2 film and comparable to those of thermal grown SiO2 film.

Truncated vascular endothelial cadherin enhances rapid endothelialization of small diameter synthetic vascular grafts

Complete and rapid endothelialization is critical to the long-term performance of synthetic vascular grafts. A fully formed endothelium is resistant to thrombosis and mitigates the development of neointimal hyperplasia, the dominant modes of acute and chronic graft failure, respectively. Significant research efforts aim to develop strategies which enhance graft endothelialization through the incorporation of surface ligands that promote the attachment and growth of endothelial cells. In native vessels these functions are regulated by the adhesion molecule vascular endothelial cadherin (VE-Cad). VE-Cad is exclusive to endothelial cells and possesses high self-affinity, forming homodimers with VE-Cad on adjacent endothelial cells. Leveraging this targeted binding ability, we developed a graft functionalization approach using a recombinant truncated form of VE-Cad (VEtr). VEtr contains only the domains responsible for self-interaction, recognition and adhesion. Using the plasma functionalization technique, plasma immersion ion implantation (PIII) technique we immobilize VEtr onto the surface of electrospun polycaprolactone (PCL). VEtr scaffolds achieved a nearly 2-fold increase in attachment and spreading, and a 2.5-fold increase in proliferation of human coronary artery endothelial cells (HCAECs) compared with control scaffolds in vitro. Following 14-day implantation in a mouse carotid artery model, VEtr grafts showed ∼90% CD31-positive endothelial coverage. The benefits of this enhanced endothelialization included an ∼88% reduction in fibrin deposition (early thrombosis) as well as ∼63% reduction in macrophage recruitment (early neointimal hyperplasia). These findings highlight VEtr functionalization as a promising approach for rapid graft endothelialization which may potentially improve the long-term performance of synthetic vascular grafts.

A combination strategy of functionalized polymer coating with Ta ion implantation for multifunctional and biodegradable vascular stents

Biodegradable stents made of magnesium (Mg) and its alloys have been developed to minimize persistent inflammation or in-stent restenosis, which are the main problems for permanent stents. However, their rapid corrosion behavior under physiological conditions leads to poor vascular compatibility and premature structural failure, which remains an important unsolved clinical problem. Herein, we demonstrate a new strategy for solving this problem by combining poly (ether imide) (PEI) coating and subsequent tantalum (Ta) ion implantation. The PEI coating covers the whole surface of the Mg stent uniformly via a spray coating technique and provides Mg with superior corrosion resistance and stable sirolimus-carrying ability. Ta ion implantation is conducted by a sputtering-based plasma immersion ion implantation technique only onto the luminal surface of the PEI-coated Mg stent. Its extremely short processing time (< 30 s) permits preservation of the PEI coating's corrosion protection ability and sirolimus loading characteristics. In addition, a Ta-implanted skin layer that forms on the topmost surface of the PEI coating plays an effective role in not only preventing a rapid release of sirolimus from the surface but also improving the PEI coating's surface hydrophilicity. Based on in vitro cellular response and blood compatibility tests, Ta ion implantation leads to the improvement of endothelial cell adhesion/proliferation and suppression of platelet adhesion/activation regardless of sirolimus loading. These results indicate that the combination of PEI coating and Ta ion implantation has significant innovative potential to provide excellent vascular compatibility and prevent in-stent restenosis and thrombosis.

Construction of tantalum/poly(ether imide) coatings on magnesium implants with both corrosion protection and osseointegration properties

Poly(ether imide) (PEI) has shown satisfactory corrosion protection capability with good adhesion strength as a coating for magnesium (Mg), a potential candidate of biodegradable orthopedic implant material. However, its innate hydrophobic property causes insufficient osteoblast affinity and a lack of osseointegration. Herein, we modify the physical and chemical properties of a PEI-coated Mg implant. A plasma immersion ion implantation technique is combined with direct current (DC) magnetron sputtering to introduce biologically compatible tantalum (Ta) onto the surface of the PEI coating. The PEI-coating layer is not damaged during this process owing to the extremely short processing time (30 s), retaining its high corrosion protection property and adhesion stability. The Ta-implanted layer (roughly 10-nm-thick) on the topmost PEI surface generates long-term surface hydrophilicity and favorable surface conditions for pre-osteoblasts to adhere, proliferate, and differentiate. Furthermore, in a rabbit femur study, the Ta/PEI-coated Mg implant demonstrates significantly enhanced bone tissue affinity and osseointegration capability. These results indicate that Ta/PEI-coated Mg is promising for achieving early mechanical fixation and long-term success in biodegradable orthopedic implant applications.

Improvement on UHMWPE and PMMA Surface Flashover Under Atmospheric Pressure Using PIII Processing

Polymers are plastic materials used as insulators in power supplies, pulsers, transformers, etc., because of their low cost and excellent insulating properties. However, in several applications, the insulating performance of these materials is limited by the surface flashover instead of the dielectric bulk breakdown (BD). On the other hand, many works have demonstrated that the material hydrophobicity has a huge effect on the increase of resistance to surface flashover in polymers. In this article, to change this material property, the plasma immersion ion implantation (PIII) technique has been used for the treatment of sample surfaces of two important polymers: ultrahigh molecular weight polyethylene (UHMWPE) and poly-methyl-methacrylate (PMMA) used in medical and industrial applications, respectively. By means of the PIII treatment, it was shown that the surface BD voltage of such polymers has increased, improving the resistance to surface flashover. Contact angle diagnostic and atomic force microscopy (AFM) were measured, respectively, for the surface hydrophobicity and roughness to correlate with the increase of the surface BD voltage. Moreover, a special BD testing pulser is employed to assess the polymer resistance to surface flashover by measuring the corresponding BD voltage under atmospheric pressure.

Study of nitrogen implantation in Ti surface using plasma immersion ion implantation & deposition technique as biocompatible substrate for artificial membranes.

The present investigation reports the modification of Ti substrates by a plasma technique to enhance their physio-chemical properties as biocompatible substrates for the deposition of artificial membranes. For that purpose, nitrogen ions are implanted into Ti substrate using the plasma immersion ion implantation & deposition (PIII&D) technique in a capacitively coupled radio frequency plasma. The plasma was characterized using optical emission spectroscopy, together with radio frequency compensated Langmuir probe, while the ion current towards the substrate was measured during the implantation process using an opto-electronic device. X-ray photoelectron spectroscopy (XPS) was used for chemical analysis of the surface, confirming the presence of δ-TiN. The penetration depth of the nitrogen ions into the Ti substrate was measured using secondary ions mass spectroscopy (SIMS) while the morphological changes were observed using atomic force microscopy (AFM). A calorimetric assay was used to prove that the TiN samples maintain the biocompatibility of the untreated Ti surface with its native oxide layer. The ion implantation increases the load bearing ability of Ti surface by the formation of α-Ti(N) and δ-TiN phases on the sub-surface of Ti, and maintains the bio compatibility of Ti surface. After the plasma treatment a thin layer of chitosan (CH) was deposited in order to provide a moisturizing matrix for the artificial membrane of 1,2-dipalmitoyl-sn-3- phosphor glycerocholine (DPPC). The CH and subsequently the DPPC were deposited on the plasma deposited TiN substrate by using physical vapor deposition. The formation of artificial membranes was confirmed by AFM, measuring the topography at different temperatures and performing force curves.

The responses of human gingival fibroblasts to magnesium-doped titanium.

The titanium (Ti) implant is widely used in implant dentistry; yet peri-implantitis has always been one of the most common and serious complications. Here, we demonstrated that magnesium-doping would be an effective way of enhancing the integration between implant surfaces and gingival tissues, which is critical to peri-implant health. The magnesium (2.76-6.35 at %) was immobilized onto the titanium substrate by a magnesium plasma immersion ion implantation (Mg-PIII) technique. Mg-PIII treatments did not alter surface topographies of the original titanium substrate but improved its hydrophilicity. The in vitro study including cell viability, adhesion, proliferation, migration, and real-time polymerase chain reaction assays disclosed improved adhesion, proliferation, migration, and extracellular matrix remodeling abilities of human gingival fibroblasts (HGFs) on the magnesium-doped titanium. The results of western blot suggested that the Mg-modified titanium induced the phosphorylation of AKT through the activation of PI3K. Our results revealed that magnesium-doping would potentially enhance soft tissue sealings by promoting cellular functions of HGFs in a dose-dependent manner, boding well for its applications on surfaces of implant necks in early peri-implant soft tissue integrations.

Plasma‐immersion ion implantation: A path to lower the annealing temperature of implanted boron emitters and simplify PERT solar cell processing

AbstractIon implantation is a suitable and promising solution for the massive industrialization of boron doping, which is a crucial process step for most next‐generation solar cells based on crystalline silicon (c‐Si). However, the use of ion implantation for boron doping is limited by the high temperature (in the 1050°C range) of the subsequent activation anneal, which is essential to dissolve the boron clusters and reach a high‐emitter quality. In this work, we propose the use of plasma‐immersion ion implantation (PIII) from B2H6 gas precursor instead of the standard beamline ion implantation (BLII) technique to decrease this temperature down to 950°C. PIII and BLII boron emitters were compared with annealing temperatures ranging from 950°C to 1050°C. Contrary to BLII, no degradation of the emitter quality was observed with PIII implants annealed at 950°C along with a full activation of the dopants in the emitter. At 1000°C, emitter saturation current densities (J0e) below 21 fA/cm2 were obtained using the PIII technique regardless of the tested implantation doses for sheet resistances between 110 and 160 Ω/sq. After metallization steps, the metal/emitter contact resistances were assessed, indicating that these emitters were compatible with a conventional metallization by screen‐printing/firing. The PIII boron emitters' performances were further tested with their integration in n‐type passivated emitter rear totally diffused (PERT) solar cells fully doped by PIII. Promising results already show a conversion efficiency of 20.8% using a lower annealing temperature than with BLII and a reduced production cost.

Reversing an S-kink effect caused by interface degradation in organic solar cells through gold ion implantation in the PEDOT:PSS layer

In this work, we performed a study on the recovery of the photovoltaic performance of an ITO/PEDOT:PSS/P3HT:PCBM/Ca/Al solar cell after the hole transport layer (PEDOT:PSS) had been degraded by contact with the environment. A device that was fully built in an inert environment exhibited a fill factor (FF) of 0.64, while the device whose hole transport layer was exposed to air presented a FF equal to 0.2. In addition, the J-V characteristic curve of the degraded device did not follow the photovoltaic pattern exhibiting the degenerate S shape. However, the elimination of the deleterious effect was achieved by bombarding gold ions on the contaminated surface of PEDOT:PSS by means of the Metal Plasma Immersion Ion Implantation technique. Due to the low energy of the ionic beam of gold, the implanted gold atoms were located at few nanometers off the surface, forming nanometric clusters, that is, gold nanoparticles. Most probably, the degradation of the J-V photovoltaic curve, represented by the S-kink effect, was caused by the appearance of a potential barrier at PEDOT:PSS/P3HT:PCBM interface, which was demolished by the gold nanoparticles that have work function close to HOMO of P3HT. This S-kink effect was also simulated by using an equivalent circuit model constituted by a two-diode circuit, one of which plays the role of the undesirable potential barrier formed at the PEDOT:PSS/P3HT:PCBM interface. Our analysis shows that deposition of gold nanoparticles next to the interface recovers the good hole injection condition from the PEDOT:PSS into the active layer, restoring the fill factor and the device efficiency.

Effect of cathode composition on microstructure and tribological properties of TiBN nanocomposite multilayer coating synthesized by plasma immersion ion implantation and deposition

Nanocomposite multilayer TiBN coatings were prepared on Si (100) and 9Cr18Mo substrates using TiBN composite cathode plasma immersion ion implantation and deposition technique (PIIID). Synthesis of TiBN composite cathodes was conducted by powder metallurgy technology and the content of hexagonal boron nitride (h-BN) was changed from 8% to 40% (mass fraction). The as-deposited coatings were characterized by energy dispersive spectrometer (EDS), grazing incidence X-ray diffraction (GIXRD), Fourier Transform Infrared Spectroscopy (FTIR) and high resolution transmission electron microcopy (HRTEM). EDS results show that the B content of the coatings was varied from 3.71% to 13.84% (molar fraction) when the composition of the h-BN in the composited cathodes was changed from 8 % to 40% (mass fraction). GIXRD results reveal that the TiBN coatings with a B content of 8% has the main diffraction peak of TiN (200), (220) and (311), and these peaks disappear when the B content is increased. FTIR analysis of the multilayer coatings showed the presence of h-BN in all coatings. TEM images reveal that all coatings have the characteristics of self-forming nanocomposite multilayers, where the nanocomposites are composed of face-centered cubic TiN or h-BN nanocrystalline embedded in amorphous matrix. The tribological tests reveal that the TiBN coatings exhibit a marked decrease of coefficient at room temperature (~0.25). The improved properties were found to be derived from the comprehensiveness of the self-forming multilayers structure and the h-BN solid lubrication effects in the coatings.

Corrosion, wear, and cell culture studies of oxygen ion implanted Ni–Ti alloy

To increase the biocompatibility of nickel–titanium (Ni–Ti) alloy substrates, oxygen ions have been implanted by the plasma immersion ion implantation (PIII–O) technique at low temperature without affecting the substrate properties. The implanted Ni–Ti surface is characterized for microhardness and composition. Energy‐dispersive spectroscopy and X‐ray photoelectron spectroscopy investigations show the replacement of native oxide on the alloy by a compact oxide during the implantation process. The corrosion behaviors of untreated substrate and PIII–O samples are investigated using potentiodynamic polarization and electrochemical impedance spectroscopy in simulated body fluid (Hanks' solution). Polarization and electrochemical impedance spectroscopy studies reveal nearly ideal capacitor behavior with better passivation characteristics for the oxygen‐implanted substrate. Sliding wear studies reveal lower friction of coefficient for the implanted layers as compared with the substrate. The bare and surface modified Ni–Ti alloy samples are evaluated for biocompatibility using osteoblast‐like cells (MG‐63). Cellular behavior in terms of cell morphology along with the viability and proliferations is evaluated by using scanning electron microscopy and in vitro cell culture assay, respectively. The results clearly show that oxygen implantation by PIII–O provides a better compatible surface for cell attachment and growth. The modified surface exhibits a higher percentage of cell viability demonstrating the enhanced biocompatibility of the oxygen‐implanted surface compared with bare Ni–Ti alloy. Copyright © 2017 John Wiley &amp; Sons, Ltd.

RETRACTED ARTICLE: In vitro and in vivo responses of macrophages to magnesium-doped titanium

Modulating immune response to biomaterials through changing macrophage polarization has been proven to be a promising strategy to elicit beneficial outcomes in tissue repair. The objective of this study was to evaluate the response of macrophage polarization to titanium doped with magnesium (0.1~0.35%), which was prepared through the magnesium plasma immersion ion implantation (Mg PIII) technique. The M1/M2 polarization profile of macrophages was investigated using a murine cell line RAW 264.7 in vitro and a murine air pouch model in vivo. Our results demonstrated that the Mg PIII-treated titanium induced a higher percentage of M2 macrophages and higher concentrations of the anti-inflammatory cytokines interleukin (IL)-4 and IL-10. Genes encoding two growth factors, bone morphogenetic protein 2 (BMP2) and vascular endothelial growth factor (VEGF) were up-regulated, thus indicating the ability of the M2 phenotype to promote wound healing. The nuclear factor κB (NF-κB) signalling pathway was down-regulated. In vivo the Mg PIII -treated titanium elicited a similar effect on macrophage polarization and induced thinner fibrous capsule formation and a decrease in infiltrated cells. These results indicate that Mg PIII treatment has the immunomodulatory potential to elicit the pro-healing M2-polarized macrophage phenotype, thus providing new insight into the development of immunomodulatory biomaterials.

Mn-containing titanium surface with favorable osteogenic and antimicrobial functions synthesized by PIII&D

Reasonable incorporation of manganese into titanium is believed to be able to enhance the osteogenic and antibacterial activities of orthopedic implants. However, it is still a challenge to compromise Mn-induced cytotoxicity and better develop its biocompatibility and antimicrobial ability. To pinpoint this issue, a stable Mn ion release platform was created on Ti using plasma immersion ion implantation and deposition (PIII&D) technique. Compared with as-etched titanium, as a result, promoted antibacterial abilities against gram-negative bacteria species and enhanced osteogenic-related gene expressions on rBMMSC were observed on Mn-containing sample. Meanwhile, the Mn-containing samples showed no obvious cytotoxicity. Our results here provide insight to be better understanding the relationships between additives-induced biological performance and the dose, state, and stability of the doped element.

Boron Emitter Formation by Plasma Immersion Ion Implantation in n-type PERT Silicon Solar Cells

The use of plasma immersion ion implantation (PIII) is a relevant approach for the development of advanced solar cells technologies at lower cost (€/Wp). In this paper, we report on the development of homogeneous boron (B) doping of n-type crystalline silicon (cSi) substrate by the PIII technique. Using diborane (B2H6) as gas precursor, various doping profiles were identified fitting the requirements for boron-doped emitters in n-type PERT solar cells. Particularly, saturation current density (J0e) of 50 fA/cm2 were achieved on symmetrical samples for a 94 Ω/sg textured B-emitter passivated with SiO2/SiN stack. Bifacial n-type Passivated Emitter Rear Totally-diffused (n-PERT) solar cells were fabricated using the PIII technology and conversion efficiencies up to 19.8% on 239 cm2 Cz-Si wafers were obtained. As a consequence, these results indicate that PIII can compete with beamline technology but will have lower running cost. It is therefore a promising technology to create high efficiency cSi solar cells.