Matrix Coating Research Articles

Impact of polyurethane versus acellular dermal matrix coating on prepectoral reconstruction outcomes: Interface does matter

BackgroundInterfaces continue to be used in prepectoral breast reconstruction to refine breast appearance, but more clinical data are required to assess their effectiveness. This study compares the rates of capsular contracture, breast esthetics, and patient satisfaction between two commonly used interface materials, acellular dermal matrix (ADM) and polyurethane (PU) foam. MethodsA cross-sectional assessment was conducted on all patients who underwent prepectoral direct-to-implant reconstruction with an interface material between June 2018 and June 2022. We compared capsular contracture rates (assessed in-person), esthetic outcomes (evaluated by a three-member panel using a specially designed scale), and patient satisfaction (measured using the Breast-Q questionnaire) among the members of the interface groups. ResultsAmong the 79 reconstructed breasts (20 bilateral cases), 35 were reconstructed using ADM and 44 using PU implants. The ADM group had a significantly higher frequency of Baker III/IV capsular contracture compared with the PU group (14.3% vs. 0%, p = 0.014) and lower ratings from the panel in terms of capsular contracture (median 3.7 vs. 4.0, p < 0.001). PU reconstructions scored worse in implant visibility (median 2.3 vs. 3.3, p < 0.001) and rippling (median 3.0 vs. 3.7, p < 0.001). However, after appropriate adjustment for confounders, no significant differences in overall appearance and patient satisfaction were found. ConclusionsADM reconstructions are prone to capsular contracture with all their related esthetic issues, but PU implants have certain cosmetic flaws, such as implant visibility and malposition. Since each technique has its own limitations, neither the experienced surgeons nor patients exhibited a clear preference for either approach.

Encapsulation of Ethanol Extract Sonneratia Alba Leaves with Inulin Matrix Coating as an Antioxidant Supplement

Encapsulation of Ethanol Extract Sonneratia Alba Leaves with Inulin Matrix Coating as an Antioxidant Supplement

Oxidation Study of Ni-W Alloy Matrix Coating Reinforced with Multiple Dissimilar Nanoparticles

Oxidation Study of Ni-W Alloy Matrix Coating Reinforced with Multiple Dissimilar Nanoparticles

Human Adipose-Derived Mesenchymal Stem Cell-Secreted Extracellular Matrix Coating on a Woven Nanotextile Vascular Patch for Improved Endothelial Cell Response.

Biomedical implants possessing the structural and functional characteristics of extracellular matrix (ECM) are pivotal for vascular applications. This study investigated the potential of recreating a natural ECM-like structural and functional environment on the surface of biodegradable polymeric nanotextiles for vascular implants. Human adipose-derived mesenchymal stem cells (MSCs) were grown on a suitably engineered polycaprolactone (PCL) nanofibrous textile and were allowed to modify its surface through the deposition of MSC-specific ECM. This surface-modified nanotextile showed mechanical characteristics and functionality appropriate for vascular patch material. The uniformity of ECM coating significantly improved the viability, proliferation, and migration of human endothelial cells compared to bare and xenogeneic collagen-coated PCL nanotextile patches. Thus, a polymeric nanotextile, which is surface modified using MSC-driven ECM, provided a rapid and improved endothelialization, thereby suggesting its potential for vascular patch applications.

Preparation and high-temperature tribological performance of laser clad MoNi coatings with chromium addition

In order to enhance the wear resistance of MoNi matrix coatings at elevated temperature, high-temperature wear resistant MoNi matrix coatings with different Cr contents (3.0 wt%, 7.0 wt% and 11.0 wt%) were prepared on the 718 alloy substrate by laser cladding. The high-temperature tribological performance was investigated sliding against Si3N4 ceramic ball by using ball-on-disk tribo-tester from room temperature to 1000 °C. The effects of chromium addition on the microstructure and the tribological performance of coatings were systematically studied. The coatings with dendritic structure consisted of Mo, Cr9Mo21Ni20 and Cr1.12Ni2.88 phases. The coatings showed a good metallurgical bonding interface with the substrate. There was a critical value of Cr content which could best reinforce the high-temperature wear resistance of MoNi matrix coating. The coating containing 7 wt% Cr had the best wear resistance over a wide temperature range, which was due to the in-situ formed salt compounds, high hardness and oxide lubricating film. The wear mechanism of three coatings transferred from the fatigue wear and abrasive wear to the oxidative wear with the increase in testing temperature.

Reinforcing Mechanism of WC Particles in Fe-Based Amorphous Matrix Coating on Magnesium Alloy Surface.

To protect magnesium alloy surfaces from wear and corrosion, an Fe-based amorphous coating was prepared on WE43 through the Ni60 interlayer by high-velocity oxygen-fuel (HVOF) spraying. The porosity was ~1%, and the amorphous content exceeded 90%. The wear and corrosion resistance of the composite coating with WC particles wrapped in a Ni layer as the reinforcing phase were compared with that of the completely amorphous coating. The friction coefficient (COF) of the composite coating was 0.3, which is only half of that of the WE43 substrate, and the composite coating exhibited a more stable wear behavior than the completely amorphous coating. The corrosion tendency of the composite coating is lower than that of stainless steel, with a corrosion potential of −0.331 V, and the addition of WC particles did not deteriorate the corrosion resistance considerably. The bonding mechanism of the bonding interface between the amorphous structure and the particles of the reinforcing phase was investigated by transmission electron microscopy (TEM). Reinforcing particles were confirmed to form metallurgical bonding with the coating. It was found that the Ni layer showed excellent bonding performance in the form of a mixture that is amorphous and nanocrystalline. Therefore, the Fe-based amorphous composite coating on a magnesium alloy surface shows a potential protective effect.

Effect of Extracellular Matrix Coating on Cancer Cell Membrane-Encapsulated Polyethyleneimine/DNA Complexes for Efficient and Targeted DNA Delivery In Vitro

Polyethyleneimine (PEI) has a good spongy proton effect and is an excellent nonviral gene vector, but its high charge density leads to the instability and toxicity of PEI/DNA complexes. Cell membrane (CM) capsules provide a universal and natural solution for this problem. Here, CM-coated PEI/DNA capsules (CPDcs) were prepared through extrusion, and the extracellular matrix was coated on CPDcs (ECM-CPDcs) for improved targeting. The results showed that compared with PEI/DNA complexes, CPDcs had core-shell structures (PEI/DNA complexes were coated by a 6-10 nm layer), lower cytotoxicity, and obvious homologous targeting. The internalization and transfection efficiency of 293T-CM-coated PEI70k/DNA capsules (293T-CP70Dcs) were 91.8 and 74.5%, respectively, which were higher than those of PEI70k/DNA complexes. Then, the internalization and transfection efficiency of 293T-CP70Dcs were further improved by ECM coating, which were 94.7 and 78.9%, respectively. Then, the internalization and transfection efficiency of 293T-CP70Dcs were further improved by ECM coating, which were 94.7 and 78.9%, respectively. Moreover, the homologous targeting of various CPDcs was improved by ECM coating, and other CPDcs also showed similar effects as 293T-CP70Dcs after ECM coating. These findings suggest that tumor-targeted CPDcs may have considerable advantages in gene delivery.

Microstructure and wear resistance of (Nb,Ti)C carbide reinforced Fe matrix coating with different Ti contents and interfacial properties of (Nb,Ti)C/α-Fe

In this work, the (Nb,Ti)C reinforced Fe matrix coatings were prepared by gas metal arc welding (GMAW) hardfacing technology. The microstructure, hardness and wear resistance of (Nb,Ti)C reinforced coatings with different Ti contents were investigated by experiments. The interfacial properties of (Nb,Ti)C/α-Fe interfaces were calculated by first principles method based on density functional theory (DFT). The experiment results show that as the Ti content in the coating changes from 0.15 to 0.41 wt%, the average diameter of NbC primary carbide grains decreases from 3.2 μm to 1.7 μm and their amount increase from 0.35 to 0.51 μm−2. The coating with 0.15 wt% Ti performs the lowest wear loss, which is 0.47 g/N ∗ cm2. From the calculated results, the interfacial combination between carbide and matrix are improved after Ti addition. The adhesion work of (Nb,Ti)C/Fe interfaces show the following order: CNb-Fe < NbC-Fe < CTiNb-Fe < CNbTi-Fe < NbTiC-Fe < TiNbC-Fe. In CTiNb-Fe, CNbTi-Fe and CNb-Fe surfaces, weak Fe-M covalent bonds are formed at the interfaces. In NbC-Fe, NbTiC-Fe and TiNbC-Fe surfaces, strong FeC and M-C covalent bond can be found at (Nb,Ti)C/α-Fe interfaces, besides, FeC ionic bonds are also formed.

Communication and Conflict Resolution in the Workplace

Good communication is required to build and maintain mutual relationship in project teams. This is because effective communication can enable a work team to achieve their goals. This stems from the fact that when the employees understand the management expectations and target goals, they will be able to do their work task based on the required standard. Also, effective communication is critical to the success of team work because the ability to work together without issues is determined by conveying the right information at the right. However, despite the crucial role played by effective communication in a productive work environment, it was found that Matrix Coating Resource Sdn Bhd (MCR) often experience communication issues among the workforce and this result to workplace conflict and employee relationship issues. It was on this note that this consultancy project critically examined the communications and employee relationships practices of MCR in order to determine key areas required to improve project tasks completion. A sample of 50 respondents were chosen from the workforce using both interview and questionnaire instruments. The study found that the staff of Matrix often experience communication issues and this leads to disagreements and misunderstanding among the workforce. This is because proper communication using appropriate channel can help to ease both the number and severity of workplace conflicts. Driven by this, it was proposed that the management of Matrix should do well to employ people with solid communication skills because this will allow them to work together cohesively and professionally, address the issue through training exercises and behaviour modeling. It should conduct constant training programmes especially for the new staff so as to improve their ability to communicate clearly and concisely with colleagues and work team members, include communication skills in the appraisal of employees’ performance and tie the organization’s objectives into performance appraisal so as to achieve the goals of the company and develop team building exercises to strengthen intra-office relationship. This is because high performance teams often become more cohesive overtime as they gain experiences working and communicating with other teams in the workplace. Therefore, exciting activities such as informal networking groups, team exercises and others so as to enable the staff to work together in a cohesive way. The team building process will allow the team members to learn the best ways to work together through team experience without issues.

Demineralized Bone Matrix Coating Si-Ca-P Ceramic Does Not Improve the Osseointegration of the Scaffold.

The aim of this study was to manufacture and evaluate the effect of a biphasic calcium silicophosphate (CSP) scaffold ceramic, coated with a natural demineralized bone matrix (DBM), to evaluate the efficiency of this novel ceramic material in bone regeneration. The DBM-coated CSP ceramic was made by coating a CSP scaffold with gel DBM, produced by the partial sintering of different-sized porous granules. These scaffolds were used to reconstruct defects in rabbit tibiae, where CSP scaffolds acted as the control material. Micro-CT and histological analyses were performed to evaluate new bone formation at 1, 3, and 5 months post-surgery. The present research results showed a correlation among the data obtained by micro-CT and the histomorphological results, the gradual disintegration of the biomaterial, and the presence of free scaffold fragments dispersed inside the medullary cavity occupied by hematopoietic bone marrow over the 5-month study period. No difference was found between the DBM-coated and uncoated implants. The new bone tissue inside the implants increased with implantation time. Slightly less new bone formation was observed in the DBM-coated samples, but it was not statistically significant. Both the DBM-coated and the CSP scaffolds gave excellent bone tissue responses and good osteoconductivity.

Effect of Collagen-Polycaprolactone Nanofibers Matrix Coating on the In Vitro Cytocompatibility and In Vivo Bone Responses of Titanium.

The objective of this study was to improve the biomechanical performance of titanium (Ti) using a biocompatible electrospun nanofiber matrix. The study is based on the hypothesis that coating a Ti surface with a nanofiber matrix (NFM) made of collagen (CG) and polycaprolactone (PCL) electrospun nanofibers could increase the mechanical fixation of Ti/bone by improving the surface and cytocompatibility properties of Ti. This study prepared Ti samples with and without CG-PCL NFM coatings. This study determined the in vitro effects of each group of Ti samples on the surface topography and cytocompatibility (osteoblast cell adhesion, proliferation, mineralization and protein adsorption) properties. This study also determined in vivo interface shear strength and bone volume fraction of each group of Ti samples with bone using a rabbit model. This study found that the CG-PCL NFM coating on Ti improved the surface roughness, osteoblast cell adhesion, proliferation, mineralization and protein adsorption properties of Ti. In vivo studies found that interface shear strength of CG-PCL NFM-coated Ti/bone samples was significantly higher compared to those values of control Ti/bone samples (p value < 0.05) due to an increase in the amount of growth of the connective tissue joining the Ti implant. Therefore, the developed CG-PCL NFM coating technique should further be investigated for its potential in clinical applications.

Processed Human Extracellular Matrix Coating of Human Amniotic Epicardial Patch Material Modulates Its Immunomodulatory Capacity

Processed Human Extracellular Matrix Coating of Human Amniotic Epicardial Patch Material Modulates Its Immunomodulatory Capacity

Metabolomic profiling of prostate cancer by matrix assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry imaging using Matrix Coating Assisted by an Electric Field (MCAEF)

In this work, we combined the use of two MALDI matrices (quercetin and 9-aminoacridine), a recently developed new matrix coating technique – matrix coating assisted by an electric field (MCAEF), and matrix-assisted laser desorption/ionization – Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICRMS) to detect and image endogenous compounds in the cancerous and non-cancerous regions of three human prostate cancer (stage II) tissue specimens. After three rounds of imaging data acquisitions (i.e., quercetin for positive and negative ion detection and 9-aminoacridine for negative ion detection), and metabolite identification, a total of 1091 metabolites including 1032 lipids and 59 other metabolites were routinely detected and successfully localized. Of these compounds, 250 and 217 were only detected in either the cancerous or the non-cancerous regions respectively, although we cannot rule out the presence of these metabolites at concentrations below the detection limit. In addition, 152 of the other 624 metabolites showed differential distributions (p<0.05, t-test) between the two regions of the tissues. Further studies on a larger number of clinical specimens will need to be carried out to confirm this large number of apparently cancer-related metabolites. The successful determination of the spatial locations and abundances of these endogenous biomolecules indicated significant metabolism abnormalities – e.g., increased energy charge and under-expression of neutral acyl glycerides, in the prostate cancer samples. To our knowledge, this work has resulted in MALDI-MS imaging of the largest group of metabolites in prostate cancer thus far and demonstrated the importance of using complementary matrices for comprehensive metabolomic imaging by MALDI-MS. This article is part of a Special Issue entitled: MALDI Imaging, edited by Dr. Corinna Henkel and Prof. Peter Hoffmann.

Electric Field-Assisted Matrix Coating Method Enhances the Detection of Small Molecule Metabolites for Mass Spectrometry Imaging.

Small molecule metabolites (SMMs, typically <500 Da) are important cellular constituents closely associated with tumor development and progression. However, in situ label-free detection of tissue SMMs has been limited due to interference from matrix and/or low sensitivity. Herein, we develop an electric field-assisted scanning-spraying (EFASS) matrix coating system to deposit matrix on tissue with crystal sizes of <10 μm, followed by matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) in negative ion mode. A comparison with other matrix deposition methods (i.e., airbrush and sublimation) using common matrixes (i.e., N-(1-naphthyl) ethylenediamine dihydrochloride (NEDC), 9-aminoacridine (9-AA), 2,5-dihydroxybenoic acid (DHB)) indicated that the EFASS system could effectively enhance detection sensitivity and the number of tissue SMMs detected. MSI of five gastric cancer tissues coated with NEDC by the EFASS system demonstrated that significantly increased levels of fatty acids (i.e., palmitic acid and oleic acid) and nucleosides monophosphate (i.e., uridine monophosphate, adenosine monophosphate, and guanosine monophosphate) and significantly decreased levels of nucleosides (i.e., inosine, guanosine, and uridine) and N-acetylneuraminic acid were observed in cancerous areas.

Thrombotic Responses of Endothelial Outgrowth Cells to Protein-Coated Surfaces

There is significant clinical need for viable small-diameter vascular grafts. While there are many graft biomaterials in development, few have been clinically successful. Evaluation of grafts with a clinically relevant model is needed to drive development. This work examined extracellular matrix coatings on the thrombotic phenotype of endothelial outgrowth cells (EOCs). EOCs were tested on flat plates and tubular grafts. Flat plate studies examined collagen I, collagen IV, fibronectin and α-elastin coatings. EOCs attached or proliferated more readily on collagen I and fibronectin surfaces as determined by total DNA. The production of activated protein C (APC) by EOCs was also dependent on the surface coating, with collagen I and fibronectin displaying a higher activity than both collagen IV and α-elastin on flat plate studies. Based on these results, only collagen I and fibronectin coatings were tested on expanded polytetrafluoroethylene (ePTFE) in the ex vivo model. Tubular samples showed significantly greater tissue factor pathway inhibitor gene expression on collagen I than on fibronectin. Platelet adhesion was not significantly different, but EOCs on collagen I produced significantly lower APC than on fibronectin, suggesting that differences exist between the flat plate and tubular cultures. Overall, while the hemostatic phenotype of EOCs displayed some differences, cell responses were largely independent of the matrix coating. EOCs adhered strongly to both fibronectin- and collagen-I-coated ePTFE grafts under ex vivo (100 ml/min) flow conditions suggesting the usefulness of this clinically relevant cell source, testing modality, and shunt model for future work examining biomaterials and cell conditioning before implantation.

Fabrication of Multiple Ceramic Particle Reinforced Iron Matrix Coating by Laser Cladding

Multiple ceramic particle reinforced iron matrix coatings were produced by laser beam melting mixture of B4C, TiO2, Al, and Fe-based self-melting powders. The results showed that the coating were mainly composed of α-Fe, TiB2, and TiC. TiB2 grains showed rectangle structures with deep grey, and that TiC grains exhibited near-cubic morphologies with light grey in the coating. The amount, type, and size of the reinforcements were influenced by the content of B4C, TiO2, and Al. Compared to the substrate, wear resistance of the composite coatings were significantly improved. Furthermore, the coatings possessed more effective protection for scratching and plastic deformation.

Automated MALDI Matrix Coating System for Multiple Tissue Samples for Imaging Mass Spectrometry

Uniform matrix deposition on tissue samples for matrix-assisted laser desorption/ionization (MALDI) is key for reproducible analyte ion signals. Current methods often result in nonhomogenous matrix deposition, and take time and effort to produce acceptable ion signals. Here we describe a fully-automated method for matrix deposition using an enclosed spray chamber and spray nozzle for matrix solution delivery. A commercial air-atomizing spray nozzle was modified and combined with solenoid controlled valves and a Programmable Logic Controller (PLC) to control and deliver the matrix solution. A spray chamber was employed to contain the nozzle, sample, and atomized matrix solution stream, and to prevent any interference from outside conditions as well as allow complete control of the sample environment. A gravity cup was filled with MALDI matrix solutions, including DHB in chloroform/methanol (50:50) at concentrations up to 60mg/mL. Various samples (including rat brain tissue sections) were prepared using two deposition methods (spray chamber, inkjet). A linear ion trap equipped with an intermediate-pressure MALDI source was used for analyses. Optical microscopic examination showed a uniform coating of matrix crystals across the sample. Overall, the mass spectral images gathered from tissues coated using the spray chamber system were of better quality and more reproducible than from tissue specimens prepared by the inkjet deposition method.

Effect of Al Content on the Microstructure and Property of TiC/Al Ceramic Matrix Coating Deposited by Laser Cladding on Ti-6Al-4V Alloy

Laser surface cladding of Ti-6Al-4V alloy by Ti+C+Al powders (Titanium and carbon powders with an atomic ratio of 1:1 were mixed with 20-40wt.% aluminum powders) was investigated. TiC particles were in situ formed mainly during the solidification. Effect of Al content on the porosity and microstructure of the cladding layer was studied. The resultant microstructure in the modified surface layer was characterized and the micro-hardness on the cladding layers was measured, as well as the wear rates. The results show that the coating had good metallurgical bonding with substrate when the Al mass fraction in Al-Ti-C system is 30 %. The micro-hardness of coating is 802HV0.5 which is 2~3 times as that of the Ti-6Al-4V alloy approximately.

Laser Alloying of Multi-Carbides Reinforced Metal Matrix Coating on a Ductile Iron

A ductile iron coated with metal-matrix pastes containing hard phase TiC and CrxCy was laser alloyed by an Nd: YAG laser and a CO2 laser. The microstructure, composition and wear resistance were analyzed by scanning electron microscopy (SEM), incorporating energy dispersive spectrum (EDS), X-ray diffraction analysis (XRD) and friction wear tester respectively. Results revealed that the alloyed area was composed by alloyed zone and heat affected zone. The microstructure of the alloyed layer was significantly influenced by the laser beam kind. Finer grains and fewer cementites were contained in the alloyed layer produced by Nd: YAG laser. Friction and wear experiments showed that the alloyed layer had better tribology properties.

Microstructure and polarisation behaviour of TiN–TiB2 matrix coating prepared by reactive plasma spraying

Two TiN–TiB2 matrix coatings were prepared by reactive plasma spraying with two spraying powders (Ti+B4C+Cr, Ti+B4C). Their microstructure, phases, microhardness and polarisation behaviours in 3·5 wt-% NaCl solution have been investigated by SEM, XRD, hardness tester and electrochemical analyser. The thermodynamics analysis for reactive plasma spraying was discussed and the effect of addition of Cr on adiabatic temperature of TiB2 forming reaction was also analysed. The thermodynamics analysis shows that the reaction temperature during reactive spraying process is >2030 K. To satisfy the criterion of self-propagating high temperature TiB2 forming reaction, the addition of Cr should be >192·6 wt-% of the total weight of Ti and B4C. The experimental results show that the addition of Cr decreases the stress in the coating so as to the cracks of coating at the expense of microhardness, yet the microhardness of both two coatings is a high value. The corrosion resistance of TiN–TiB2 matrix coating was greatly improved. The anodic polarisation curve of TiN–TiB2 coating includes a narrow activation zone and a broad passivation zone, which indicates the stability of coating is very excellent. The addition of Cr increases the corrosion potential of coating, yet an overpassivation zone appears, which is due to the breakage of passivation film.