Laser-assisted calcium phosphate deposition on polymer substrates in supersaturated solutions

Abstract

Calcium phosphate (CaP) deposition was induced on optically semitransparent polymers irradiated with laser in a supersaturated CaP solution, but not on a transparent polymer.

Physicochemical fabrication of calcium phosphate-based thin layers and nanospheres using laser processing in solutions

“…7), but not on the PE substrate. 40 These results correlated well with the light absorption ability of the substrate at the employed laser wavelength (355 nm) and with the temperature change of the CP solution during laser irradiation of the substrate without a temperature-controlled water bath. For example, the PE substrate exhibited little light absorption at 355 nm and negligible heating of the CP solution under irradiation, thereby inducing no CaP precipitation during the LAB process.…”

“…Conventionally, CaP-based thin layers and nanoparticles have been fabricated by either physical or chemical process (this will be described in more detail later). Recently, we developed a new physicochemical process for the fabrication of CaP-based thin layers [38][39][40][41][42] and nanospheres 43,44 by combining a physical laser process and a chemical precipitation process. In this process, pulsed laser irradiation is performed without focusing to a metastable or labile supersaturated CaP solution to induce lightmaterial interactions at a laser-irradiated substrate surface (for thin layer fabrication) or in the entire solution (for sphere fabrication) ( Fig.…”

“…[50][51][52][53][54] Such two-step CaP coating techniques are described in Section 2.2. Recently, these twostep techniques have been refined, and one-step CaP coating was achieved using a laser-assisted biomimetic (LAB) process; [38][39][40][41][42] this process is described in detail in Section 2.3.…”

“…Our CaP coating technique using the LAB process is applicable to not only EVOH, but other polymeric, ceramic, and metallic substrates that can absorb sufficient laser light energy. [39][40][41][42] However, it is not applicable to substrates with insufficient laser absorption because laser absorption by a substrate is a prerequisite for CaP precipitation in the LAB process, as verified in the preceding section.…”

“…We have tested four substrates in addition to EVOH: polyethylene terephthalate (PET, polymer), polyethylene (PE, polymer), sintered HAp (sHAp, ceramic), and titanium (Ti, metal). After the LAB process using UV laser (l = 355 nm), CaP layers were formed on the PET, 40 sHAp, 39 and Ti substrates 41,42 (Fig. 7), but not on the PE substrate.…”