Comparison between the Astaxanthin Release Profile of Mesoporous Bioactive Glass Nanoparticles (MBGNs) and Poly(3-hydroxybutyrate- co-3-hydroxyvalerate) (PHBV)/MBGN Composite Microspheres

Abstract

In recent years, composite biomaterials have attracted attention for drug delivery applications due to the possibility of combining desired properties of their components. However, some functional characteristics, such as their drug release efficiency and likely side effects, are still unexplored. In this regard, controlled tuning of the drug release kinetic via the precise design of a composite particle system is still of high importance for many biomedical applications. This objective can be properly fulfilled through the combination of different biomaterials with unequal release rates, such as mesoporous bioactive glass nanoparticles (MBGN) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microspheres. In this work, MBGNs and PHBV-MBGN microspheres, both loaded with Astaxanthin (ASX), were synthesised and compared in terms of ASX release kinetic, ASX entrapment efficiency, and cell viability. Moreover, the correlation of the release kinetic to phytotherapeutic efficiency and side effects was established. Interestingly, there were significant differences between the ASX release kinetic of the developed systems, and cell viability differed accordingly after 72 h. Both particle carriers effectively delivered ASX, though the composite microspheres exhibited a more prolonged release profile with sustained cytocompatibility. The release behaviour could be fine-tuned by adjusting the MBGN content in the composite particles. Comparatively, the composite particles induced a different release effect, implying their potential for sustained drug delivery applications.

Keywords: Astaxanthin; composite microspheres; controlled release; sustained release.

Figure 1

Particle size distribution of (a) MBGN/ASX and (b) composite microspheres; (c) Zeta potential of MBNG/ASX and composite particles. SEM micrographs showing the surface morphology of (d) MBGN/ASX and (e) composite microspheres and (f) comparison of MBGN and composite particle dimensions.

Figure 2

FTIR spectra of ASX, MBGN, MBGN/ASX, blank PHB, and composite microspheres. (λ is wavenumber).

Figure 3

(a) ASX Entrapment Efficiency and (b) cumulative release kinetic of MBGN/ASX and composite microspheres (SD as error bars, n = 3).

Figure 4

XRD patterns of (a) MBGN/ASX and (b) composite microspheres. SEM micrographs of (c) ASX/MBGN and (d) composite microspheres after 14 days of immersion in SBF.

Figure 5

Cell viability of NIH-3T3 cells treated with the composite microspheres, MBGN/ASX, blank PHBV microspheres, blank MBGN, free ASX, and cells without any treatment as control after (a) 24 h and (b) 72 h of incubation; (c) fluorescence microscopy micrographs of each condition after 72 h. (* indicates a significant difference of p ≤ 0.5 Tukey test, SD as error bars, n = 3).