Matrix-Assisted Pulsed laser Evaporation-deposited Rapamycin Thin Films Maintain Antiproliferative Activity

Abstract

Matrix-assisted pulsed laser evaporation (MAPLE) has many benefits over conventional methods (e.g., dip-coating, spin coating, and Langmuir-Blodgett dip-coating) for manufacturing coatings containing pharmacologic agents on medical devices. In particular, the thickness of the coating that is applied to the surface of the medical device can be tightly controlled. In this study, MAPLE was used to deposit rapamycin-polyvinylpyrrolidone (rapamycin-PVP) thin films onto silicon and borosilicate optical glass substrates. Alamar Blue and PicoGreen studies were used to measure the metabolic health and DNA content of L929 mouse fibroblasts as measures of viability and proliferation, respectively. The cells on the MAPLE-deposited rapamycin-PVP surfaces exhibited 70.6% viability and 53.7% proliferation compared to a borosilicate glass control. These data indicate that the antiproliferative properties of rapamycin were maintained after MAPLE deposition.

Keywords: Drug delivery; Matrix-assisted pulsed laser evaporation; Rapamycin; Thin film.

Figure 1

Schematic of the MAPLE process.

Figure 2

Representative atomic force micrograph of MAPLE-deposited rapamycin-PVP thin films on Si <100>.

Figure 3

Typical Fourier transform infrared spectrum of MAPLE-deposited rapamycin-PVP thin film (red spectrum) and dropcast coating (black spectrum), respectively.

Figure 4

Reductions in proliferation (left) and cell viability (right) were observed in L929 fibroblasts cultured on borosilicate glass coated with rapamycin using MAPLE (rapamycin-PVP) versus untreated borosilicate glass (control). Values represent of x̄ ± SD N = 3 independent replicate experiments. Bars with asterisks are significantly different from the negative control (P < 0.05).