Biopolymer Thin Films Synthesized by Advanced Pulsed Laser Techniques

This chapter provides an overview of recent advances in the field of laser-based synthesis of biopolymer thin films for biomedical applications. The introduction addresses the importance of biopolymer thin films with respect to several applications like tissue engineering, cell instructive environments, and drug delivery systems. The next section is devoted to applications of the fabrication of organic and hybrid organic–inorganic coatings. Matrix-assisted pulsed laser evaporation (MAPLE) and Combinatorial-MAPLE are introduced and compared with other conventional methods of thin films assembling on solid substrates. Advantages and limitations of the methods are pointed out by focusing on the delicate transfer of bio-macromolecules, preservation of properties and on the prospect of combinatorial libraries’ synthesis in a single-step process. The following section provides a brief description of fundamental processes involved in the molecular transfer of delicate materials by MAPLE. Then, the chapter focuses on the laser synthesis of two polysaccharide thin films, namely Dextran doped with iron oxide nanoparticles and Levan, followed by an overview on the MAPLE synthesis of other biopolymers. The chapter ends with summary and perspectives of this fast-expanding research field, and a rich bibliographic database

Composite Coatings Based on Renewable Resources Synthesized by Advanced Laser Techniques

This chapter reviews the progress and perspectives of composite materials in the form of thin films based on renewable resources for biofabrication of a new generation of medical implants with antibacterial properties. The chapter starts with an overview of the types of renewable materials that were currently studied and of the unique properties which make them perfect candidates for numerous bio‐related applications. A briefing of recent progresses in the field of advanced laser synthesis of composites from renewable and sustainable materials, as well as the relevant results in our researches is made. The discussion spans composite coatings based on renewable resources, [e.g., chitosan (CHT) and lignin (Lig)] as biomaterials intended for metallic implants. A particular attention is given to lignin synthesis in the form of thin films due to its ability to functionalize the medical implant surface while preserving the similar composition and the structural properties of the raw, renewable biomaterial. We focused on recent technological advancements (e.g., matrix‐assisted pulsed laser evaporation (MAPLE) and Combinatorial‐MAPLE) which have brought the spotlight onto renewable biomaterials, by detailing the relevant engineering data of processing. This chapter concludes that the extensions of advanced laser techniques are viable fabrication methods of a new generation of metallic implants

Laser Ablation of Biomaterials

Biomaterials, defined by high biocompatibility and biodegradability, are intensively used in medical applications, mainly to replace partial or total, damaged or destroyed hard or soft tissues. Most of them are used not only as coatings for implant coverage but also as parts for some medical devices. In the last decades, researchers sought to find the optimum processing methods and parameters to modify or deposit the biomaterial of interest. An important family of techniques, used to process a biomaterial, is represented by laser techniques, based upon laser ablation phenomenon. Laser ablation of biomaterials ensures the transference or modification with good precision and without or with minimal disruptions generated. To obtain thin coatings from biomaterials, one can use deposition techniques: pulsed laser deposition (PLD) or matrix-assisted pulsed laser evaporation (MAPLE). These techniques are chosen according to the selected biomaterial and desired performances of the obtained coating. Therefore, some sensitive biomaterials can be transferred only by MAPLE. Some results in the field of calcium phosphates deposited by PLD or MAPLE are presented, proving the usefulness of these biomaterials for medical applications

Wettability of Nanostructured Surfaces

There are many studies in literature concerning contact angle measurements on different materials/substrates. It is documented that textiles can be coated with multifunctional materials in form of thin films or nanoparticles to acquire characteristics that can improve the protection and comfort of the wearer. The capacity of oxide nanostructures to inhibit fungal development and neutralize bacteria is a direct consequence of their wetting behavior [1–6]. Moreover, the radical modification of wetting behavior of nanostructures from hydrophilic to hydrophobic when changing the pulsed laser deposition (PLD) ambient will be thoroughly discussed

Characterization of PLD grown WO3 thin films for gas sensing

Tungsten trioxide (WO3) thin films were grown by pulsed laser deposition (PLD) with the aim to be applied in gas sensors. The films were studied by atomic force microscopy (AFM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and profilometry. To study the gas sensing behavior of these WO3 films, they were deposited on quartz resonators and the quartz crystal microbalance (QCM) method was applied to analyze their gas sensitivity. Synthesis of tetragonal-WO3 films starting from a target with predominantly monoclinic WO3 phase was observed. The films deposited at 300 degrees C presented a surface topology favorable for the sorption properties, consisting of a film matrix with protruding craters/cavities. QCM prototype sensors with such films were tested for NO2 sensing. The PLD grown WO3 thin films show good sensitivity and fast reaction at room temperature, even in as-deposited state. With the presented technology, the manufacturing of QCM gas sensors is simple, fast and cost-effective, and it is also suitable for energy-effective portable equipment for on-line monitoring of environmental changes. (C) 2017 Elsevier B.V. All rights reserved