Category Archives: Biomedical

Laser Surface Texturing of Biomaterials

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By Antonio Riveiro, Ramón Soto, Rafael Comesaña, Mohamed Boutinguiza, Jesús del Val, Félix Quintero, Fernando Lusquiños, Juan Pou

One of the main requirements of a bone implant is to be able to withstand severe mechanical conditions during the required lifetime of the component. Nevertheless, the success of a bone implant relies upon the quality of the bone-implant reaction, which is markedly influenced by the surface topography and chemistry of the implant material. Biomaterials commonly used in implants only satisfy part of these requirements (see Fig. 1); for example, biomaterials such as Titanium or PEEK (poly aryl-ether-ether-ketone), have a high strength, good wear resistance, and excellent chemical resistance but their inferior bioactivity may lead to poor bone-implant interactions. Therefore, an intervening fibrous tissue layer occurs around the contact area between the bone and the implant. Continue reading →

Using UV Laser Surface Treatment to Modify the Wettability Characteristics of Polyamide 6,6 and its Effects on Osteoblast Cell Activity

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By: David G. Waugh and Jonathan Lawrence

Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, UK
Lincoln School of Engineering, University of Lincoln, UK

The need for biological implants grows year upon year and it has been realized that there is a drive within the biomedical industry for cheaper and easier to manufacture products. This could be met by the use of polymeric materials; however, it has been seen that polymeric materials can often fail clinically and be rejected by body due to the fact that the surface properties do not give rise to adequate cell growth. One way to counteract this is to treat the polymeric surfaces prior to the implantation such that they then have properties which enhance the cell response and ultimately reduce the failure/rejection rate. Many techniques have been developed for the surface treatment of polymeric materials; however, many only have the ability to modify one surface parameter at any one time and can have detrimental effects on the bulk properties. One promising and interesting method to carry out these surface treatments is that of the use of laser technology which can be applied to a number of different materials ranging from ceramics, to metals, to polymers. Lasers have the ability to change both the surface dimensions (roughness and surface pattern) and the surface chemistry simultaneously which can then lead to a change in the wettability characteristics. Wettability characteristics are those surface parameters which are directly linked to the wetting nature of materials; for instance, the contact angle is the angle the liquid droplet makes with the solid surface and the surface free energy is the energy associated with the solid surface giving rise to the contact angle observed. The wettability characteristics of a material have already been shown that they can be implemented to predict the adhesive nature of materials. As a result of this, many believe that wettability can be implemented as a tool to estimate the bioactive nature of materials. This would give a massive opportunity to the biological industry as it would allow those within the bio-implant field to have the ability to predict whether an implant will fail. Continue reading →

Femtosecond Laser 3D Micromachining for Fabricating Nanoaquariums: Exploring the Functions of Aquatic Microorganisms

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By: Koji Sugioka, Yasutaka Hanada, Katsumi Midorikawa, Ikuko Shihira Ishikawa, Hiroyuki Kawano, Atsushi Miyawaki

RIKEN – Advanced Science Institute, Brain Science Institute

It is becoming increasingly important to observe and analyze the dynamics and functions of microorganisms both for fundamental investigations (such as elucidating the functions of biological cells) and for applications to biomicro systems and medicine. We used femtosecond (fs) laser 3D micromachining to fabricate microfluidic chips (which we term nanoaquariums) for observing microorganisms. Nanoaquariums enable us to drastically reduce the observation time relative to that for the conventional observation method using Petri dishes. Furthermore, they can be used to perform highly functional analysis, which biologists have long desired to realize. We have developed a technique for fabricating nanoaquariums that involves directly forming 3D hollow microstructures with smooth internal surfaces in photostructurable glass by fs laser direct writing followed by annealing and wet etching in dilute hydrofluoric acid (see Fig. 1). This technique permits rapid prototyping of 3D microfluidic systems with different structures, which is greatly desired by biologists for observing different microorganisms. Furthermore, functional microelements such as micromechanical elements and micro optical elements can be easily integrated into the microfluidic structure, permitting more functional observation and analysis to be performed.

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