Vitamin D plays a pivotal role in calcium homeostasis and bone metabolism, whereas vitamin A deficiency can result in delayed bone growth and reduced bone mineral density. The objective of this study was to produce, characterize, and test poly(caprolactone) (PCL) and poly(lactide-co-glycolide) (PLGA) particles containing retinyl acetate and cholecalciferol. The particles were prepared by solvent displacement, whereby water and surfactant were dripped into an oil phase of polymers (PCL or PLGA) without or with vitamins A and D in acetone. The particles were characterized in terms of their size and zeta potential. The viability of stem cells was evaluated via MTT assay following a one-day exposure to particles containing 0.77 UI/ml vitamin A and 0.15UI/ml vitamin D. The findings revealed that PCL particles exhibited a zeta potential of -60 mV. In comparison, PLGA particles demonstrated a zeta potential of -39 mV. The diameter was 213 nm for PCL and 112 nm for PLGA, as determined by the Zetasizer equipment (with a detection limit of 10 µm). However, the diameter was measured above 10 µm for PLGA using optical microscopy/ImageJ. The particles did not significantly affect stem cell viability, as indicated by the absorbance values for cells incubated with the particles of PLGA, PLGA/vitamins, PCL, and PCL/vitamins for one day (p = 0.560). Therefore, the particles exhibited nano- and micrometric sizes, a high negative surface charge, and high dispersion. These materials were not cytotoxic to stem cells, indicating that polymeric particles may represent a viable retinol and cholecalciferol supplementation strategy, with potential utility in bioinks for bone tissue engineering.

Acknowledge: Office of Naval Research Global (ONRG Award N62909-21-1-2026) and National Institute of Science and Technology for Regenerative Medicine (INCT-Regenera).