scholarly journals An overview of biofunctionalization of metals in Japan

2009 ◽  
Vol 6 (suppl_3) ◽  
Author(s):  
Takao Hanawa
Keyword(s):  
Surface Modification ◽  
Metal Surface ◽  
Surface Composition ◽  
Polyurethane Composite ◽  
Modification Technique ◽  
Composition Structure ◽  
Poly Ethylene ◽  
Surface Modification Techniques ◽  
The Relationship ◽  
Metal Polymer

Surface modification is an important and predominant technique for obtaining biofunction and biocompatibility in metals for biomedical use. The surface modification technique is a process that changes the surface composition, structure and morphology of a material, leaving the bulk mechanical properties intact. A tremendous number of surface modification techniques using dry and wet processes to improve the hard tissue compatibility of titanium have been developed. Some are now commercially available. Most of these processes have been developed by Japanese institutions since the 1990s. A second approach is the immobilization of biofunctional molecules to the metal surface to control the adsorption of proteins and adhesion of cells, platelets and bacteria. The immobilization of poly(ethylene glycol) to a metal surface with electrodeposition and its effect on biofunction are reviewed. The creation of a metal–polymer composite is another way to obtain metal-based biofunctional materials. The relationship between the shear bonding strength and the chemical structure at the bonding interface of a Ti-segmentated polyurethane composite through a silane coupling agent is explained.

scholarly journals A Framework for Surface Modification by Electrical Discharge Coating using Variable Density Electrodes

2021 ◽  
Vol 309 ◽  
pp. 01093
Author(s):  
Mohd Yunus Khan ◽  
P. S. Rao ◽  
B.S. Pabla
Keyword(s):  
Surface Modification ◽  
Electrical Discharge ◽  
Variable Density ◽  
Work Piece ◽  
Hard Material ◽  
Metal Powders ◽  
Material Transfer ◽  
Modification Technique ◽  
Polarity Condition ◽  
Surface Modification Techniques

Surface modification is the process of altering physical or chemical characteristics of the work-piece surface. In this paper, various surface modification techniques have been discussed. One of the most appropriate surface modification technique is electrical discharge coating (EDC), in which the hard material is made to deposit onto the work-piece in a state of reverse polarity condition. Different mechanisms of carrying out EDC are presented. Deliberate material transfer takes place by using electrodes or by dispersant of metal powders into the di-electric. A detailed review of the literature on the theme of surface modification through the EDC has been conducted. In last, a framework for conducting surface modification by EDC employing using density electrodes of same material is presented.

Polymeric Nanoparticles for Brain Drug Delivery - A Review

2020 ◽  
Vol 21 (9) ◽  
pp. 649-660
Author(s):  
Subashini Raman ◽  
Syed Mahmood ◽  
Ayah R. Hilles ◽  
Md Noushad Javed ◽  
Motia Azmana ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Surface Modification ◽  
Polymeric Nanoparticles ◽  
Drug Loading ◽  
Preparation Methods ◽  
Brain Drug Delivery ◽  
Polymeric Nanoparticle ◽  
Relationship Of ◽  
The Relationship ◽  
The Brain

Background: Blood-brain barrier (BBB) plays a most hindering role in drug delivery to the brain. Recent research comes out with the nanoparticles approach, is continuously working towards improving the delivery to the brain. Currently, polymeric nanoparticle is extensively involved in many therapies for spatial and temporal targeted areas delivery. Methods: We did a non-systematic review, and the literature was searched in Google, Science Direct and PubMed. An overview is provided for the formulation of polymeric nanoparticles using different methods, effect of surface modification on the nanoparticle properties with types of polymeric nanoparticles and preparation methods. An account of different nanomedicine employed with therapeutic agent to cross the BBB alone with biodistribution of the drugs. Results: We found that various types of polymeric nanoparticle systems are available and they prosper in delivering the therapeutic amount of the drug to the targeted area. The effect of physicochemical properties on nanoformulation includes change in their size, shape, elasticity, surface charge and hydrophobicity. Surface modification of polymers or nanocarriers is also vital in the formulation of nanoparticles to enhance targeting efficiency to the brain. Conclusion: More standardized methods for the preparation of nanoparticles and to assess the relationship of surface modification on drug delivery. While the preparation and its output like drug loading, particle size, and charge, permeation is always conflicted, so it requires more attention for the acceptance of nanoparticles for brain delivery.

Properties and Applications of Modified Bacterial Cellulose-Based Materials

2020 ◽  
Vol 16 ◽  
Author(s):  
Munair Badshah ◽  
Hanif Ullah ◽  
Fazli Wahid ◽  
Taous Khan
Keyword(s):  
Surface Modification ◽  
Bacterial Cellulose ◽  
Degree Of Polymerization ◽  
Biomedical Science ◽  
Hydroxyl Groups ◽  
Market Demand ◽  
Ideal Candidate ◽  
Fibrous Network ◽  
Potential Applications ◽  
Surface Modification Techniques

Background: Bacterial cellulose (BC) is purest form of cellulose as it is free from pactin, lignin, hemicellulose and other active constituents associated with cellulose derived from plant sources. High biocompatibility and easy molding into desired shape make BC an ideal candidate for applications in biomedical field such as tissue engineering, wound healing and bone regeneration. In addition to this, BC has been widely studied for applications in the delivery of proteins and drugs in various forms via different routes. However, BC lacks therapeutic properties and resistance to free movement of small molecules i.e., gases and solvents. Therefore, modification of BC is required to meet the research ad market demand. Methods: We have searched the updated data relevant to as-synthesized and modified BC, properties and applications in various fields using Web of science, Science direct, Google and PubMed. Results: As-synthesized BC possesses properties such as high crystallinity, well organized fibrous network, higher degree of polymerization, and ability of being produced in swollen form. The large surface area with abundance of free accessible hydroxyl groups makes BC an ideal candidate for carrying out surface functionalization to enhance its features. The various reported surface modification techniques including, but not limited to, are amination, methylation and acetylation. Conclusion: In this review, we have highlighted various approaches made for BC surface modification. We have also reported enhancement in the properties of modified BC and potential applications in different fields ranging from biomedical science to drug delivery and paper-making to various electronic devices.

scholarly journals Osseointegration Improvement of Co-Cr-Mo Alloy Produced by Additive Manufacturing

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 724
Author(s):  
Amilton Iatecola ◽  
Guilherme Arthur Longhitano ◽  
Luiz Henrique Martinez Antunes ◽  
André Luiz Jardini ◽  
Emilio de Castro Miguel ◽  
...  
Keyword(s):  
Surface Modification ◽  
Additive Manufacturing ◽  
Bone Ingrowth ◽  
Orthopedic Implants ◽  
Coated Sample ◽  
High Mechanical Strength ◽  
Coated Surface ◽  
Surface Modification Techniques ◽  
Almost All ◽  
Cobalt Base

Cobalt-base alloys (Co-Cr-Mo) are widely employed in dentistry and orthopedic implants due to their biocompatibility, high mechanical strength and wear resistance. The osseointegration of implants can be improved by surface modification techniques. However, complex geometries obtained by additive manufacturing (AM) limits the efficiency of mechanical-based surface modification techniques. Therefore, plasma immersion ion implantation (PIII) is the best alternative, creating nanotopography even in complex structures. In the present study, we report the osseointegration results in three conditions of the additively manufactured Co-Cr-Mo alloy: (i) as-built, (ii) after PIII, and (iii) coated with titanium (Ti) followed by PIII. The metallic samples were designed with a solid half and a porous half to observe the bone ingrowth in different surfaces. Our results revealed that all conditions presented cortical bone formation. The titanium-coated sample exhibited the best biomechanical results, which was attributed to the higher bone ingrowth percentage with almost all medullary canals filled with neoformed bone and the pores of the implant filled and surrounded by bone ingrowth. It was concluded that the metal alloys produced for AM are biocompatible and stimulate bone neoformation, especially when the Co-28Cr-6Mo alloy with a Ti-coated surface, nanostructured and anodized by PIII is used, whose technology has been shown to increase the osseointegration capacity of this implant.

scholarly journals Control of Local Hardness Gradient of Metal Surface by Inclined Surface Treatment Using Ultrasonic Nanocrystal Surface Modification

2021 ◽  
Vol 8 (2) ◽  
pp. 533-546
Author(s):  
Yeong-Kwan Jo ◽  
Yeong-Wook Gil ◽  
Do-Sik Shim ◽  
Young-Sik Pyun ◽  
Sang-Hu Park
Keyword(s):  
Surface Modification ◽  
Surface Treatment ◽  
Metal Surface ◽  
Incident Angle ◽  
Surface Hardness ◽  
Parameter Study ◽  
Local Hardness ◽  
Practical Usefulness ◽  
Inclined Surface ◽  
Hardness Gradient

AbstractWe propose an effective method to control the local hardness and morphology of a metal surface by tilting the incident angle of a horn during ultrasonic nanocrystal surface modification (UNSM). In this study, surface treatment using UNSM was performed on an S45C specimen and a parameter study was conducted for optimization. The process parameters were the feeding rate, static load, striking force, and processing angle (Ф). In particular, the Ф was analyzed by tilting the horn by 0°, 10°, 20°, 30°, 40°, and 45° to understand its effect on surface hardness and changes in the morphology. From fundamental experiments, some important phenomena were observed, such as grain-microstructure changes along the processing and thickness directions. Furthermore, to verify the practical usefulness of this study, a flat and a hemispherical specimen of S45C material were treated using UNSM with various values of Ф. A significant change in hardness (an increase from 2–45%) and a gradual hardness gradient on the tested specimens could be easily realized by the proposed method. Therefore, we believe that the method is effective for controlling the mechanical hardness of a metal surface.

A Novel Approach for Metal Surface Modification

2007 ◽  
Vol 280-283 ◽  
pp. 1805-1806
Author(s):  
Zhi Jun Cao ◽  
Jia Chen Liu ◽  
Li Bin Liu ◽  
Hao Ye ◽  
Yan Qiu Wei
Keyword(s):  
Surface Modification ◽  
Wear Rate ◽  
Charge State ◽  
Metal Surface ◽  
Surface Hardness ◽  
Metallic Surface ◽  
New Approach ◽  
Novel Approach ◽  
Complex Shapes ◽  
Enhanced Surface

A new approach was developed for surface modification of metallic surface. By treating nano-zirconia particles and metal surface in different charge state, nano-zirconia particles can be dispersedly inlaid in metal surface owing to electrostatic and nanometer effects. By using this method, metal components of complex shapes, especially those having inside surfaces, might be easily improved, i.e., enhanced surface hardness and wear rate.

On the 3D Correlation between Myofibroblast Shape and Contraction

2021 ◽  
Author(s):  
Alex Khang ◽  
Emma Lejeune ◽  
Ali Abbaspour ◽  
Daniel Howsmon ◽  
Michael Sacks
Keyword(s):  
Cell Shape ◽  
Interstitial Cell ◽  
Stable State ◽  
Stress Fiber ◽  
Poly Ethylene Glycol ◽  
Critical Feature ◽  
Peg Hydrogels ◽  
Poly Ethylene ◽  
And Function ◽  
The Relationship

Abstract Cell shape is known to correlate closely with stress-fiber geometry and function, and is thus a critical feature of cell biophysical state. However, the relationship between myofibroblast shape and contraction is complex, even as well in regards to steady-state contractile level (basal tonus). At present, the relationship between myofibroblast shape and basal tonus in 3D is poorly understood. Herein, we utilize the aortic valve interstitial cell (AVICs) as a representative myofibroblast to investigate the relationship between basal tonus and overall cell shape. AVICs were embedded within 3D poly (ethylene glycol) (PEG) hydrogels containing degradable peptide crosslinkers, adhesive peptide sequences, and sub-micron fluorescent micro-spheres to track the local displacement field. We then developed a methodology to evaluate the correlation between overall AVIC shape and basal tonus induced contraction. We computed a volume averaged stretch tensor <U> for the volume occupied by the AVIC, which had three distinct eigenvalues (1.08, 0.99, and 0.89), suggesting that AVIC shape is a result of anisotropic contraction. Furthermore, the direction of maximum contraction correlated closely with the longest axis of a bounding ellipsoid enclosing the AVIC. As gel--imbedded AVIC are known to be in a stable state by three days of incubation used herein, this finding suggests that the overall quiescent AVIC shape is driven by the underlying stress-fiber directional structure and possibly contraction level.

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