Biomimetic Coatings Obtained by Combinatorial Laser Technologies

Abstract

The modification of implant devices with biocompatible coatings has become necessary as a consequence of premature loosening of prosthesis. This is caused mainly by chronic inflammation or allergies that are triggered by implant wear, production of abrasion particles, and/or release of metallic ions from the implantable device surface. Specific to the implant tissue destination, it could require coatings with specific features in order to provide optimal osseointegration. Pulsed laser deposition (PLD) became a well-known physical vapor deposition technology that has been successfully applied to a large variety of biocompatible inorganic coatings for biomedical prosthetic applications. Matrix assisted pulsed laser evaporation (MAPLE) is a PLD-derived technology used for depositions of thin organic material coatings. In an attempt to surpass solvent related difficulties, when different solvents are used for blending various organic materials, combinatorial MAPLE was proposed to grow thin hybrid coatings, assembled in a gradient of composition. We review herein the evolution of the laser technological process and capabilities of growing thin bio-coatings with emphasis on blended or multilayered biomimetic combinations. These can be used either as implant surfaces with enhanced bioactivity for accelerating orthopedic integration and tissue regeneration or combinatorial bio-platforms for cancer research.

Hybrid Nanocomposite Thin Films for Photovoltaic Applications: A Review

“…The MAPLE deposition involves the following steps: (i) firstly, the organic material is dissolved in the appropriate solvent, the solution being stirred for homogenization; (ii) the organic solution is frozen in the liquid nitrogen in order to obtain the solid frozen target used in the deposition; and (iii) during the MAPLE process, when the laser pulses impinged the target, the energy absorbed by the matrix is converted in thermal energy, the solvent and organic molecules being ejected simultaneously from the target: the volatile solvent molecules are pumped away by the vacuum system, whereas the organic molecules form the layer on the surface of the substrate [ 65 , 67 ]. It is worth mentioning that during the MAPLE process, organic and solvent clusters can be ejected toward the substrate resulting in the formation of droplets or aggregates structures on the surface of the deposited films, their presence influencing the contact between the layers from the developed structure [ 68 ]. Nevertheless, in the MAPLE deposition, an accurate control of the thin film thickness can be achieved by tuning the experimental parameters such as laser fluence, repetition rate, target-substrate distance, temperature of the substrate and number of the applied laser pulses.…”

“…Although UV lasers are usually employed in the MAPLE process, other MAPLE-based techniques, such as resonant infrared-MAPLE (RIR-MAPLE) or emulsion-based RIR-MAPLE using IR pulses, were developed for the deposition involving organic solvents characterized by vibrational frequencies in the infrared region [ 69 ]. Additionally, combinatorial-MAPLE (C-MAPLE) is an alternative technique used to grow, in a single-step process, thin hybrid bio-coatings with a gradient of composition, as was reviewed in [ 68 ].…”

Physical Vapour Deposited Biomedical Coatings

“…Furthermore, this Special Issue suitably demonstrates the current landscape for future generations of biological layers containing two extensive review articles on the emerging popularity of more recent/novel manufacturing methods and their relevance to biomaterial applications. These specifically pertain to the Pulsed Electron Deposition (PED) [6] and Combinatorial Laser deposition technologies [7].…”

“…Axente et al [7] reviews PLD-based techniques (well-known for preservation of stoichiometry and tune-ability of input energies for desired chemistries/reactability with working gases (e.g., for the deposition of TiN coatings)). The state-of-the-art manufacturing development is described, with emphasis on the Matrix Assisted Pulsed Laser Evaporation (MAPLE) method's capability to fabricate thin (heat-sensitive) organic, inorganic, and hybrid organic-inorganic films.…”

“…Some applications include deposition of fibronectin, bovine serum albumin-functionalized graphene oxide nanomaterials. Axente et al [7] focuses on the "Combinatorial" approach, referring to the use of multiple laser systems to produce material blends across a substrate, demonstrating formation of strontium doped HA-zinc doped β-tricalcium phosphate in bone regenerative applications, sulphated Halomonas Levan blended quaternized low molecular weight chitosan for antibacterial properties, graphene oxide nanomaterials with hybrid bovine serum albumin, and introduced Dabrafenib/Trichostatin A drugs for targeting melanoma cells.…”