Evaluation of solubility and cytotoxicity of lanthanum-doped phosphate glasses nanoparticles for drug delivery applications

Abstract This paper examined the preparation and characterization of lanthanum-doped phosphate glasses nanoparticles designed for effective management of bone regeneration and associated infections. Glasses incorporated different La 2 O 3 contents (0, 5 and 10 mol%) were prepared successfully by a modified alkoxide sol-gel method. They were encoded as P0, PL5 and PL10. Specific surface area and the total pore volume of the glasses were found to decrease by the addition of La 2 O 3 . TEM photos showed that glasses were spherical nanoparticles and incorporated uniform mesopores which increased in size by the increase of La 2 O 3 contents. On the other hand, the dissolution of glasses nanoparticles was tested in different media (distilled H 2 O, SBF and tris-HCl buffer). The results showed that lanthanum-modified glasses demonstrated faster ionic release profiles of phosphate species relative to the base glass with faster dissolution from PL5 relative to PL10 in both distilled H 2 O and tris-HCl buffer. Furthermore, the possibility of using such glasses as a drug carrier was examined by loading the ciprofloxacin onto samples and studied its release profile. A sustained drug release profile from all phosphate glasses was achieved. Additionally, the incorporation of La 2 O 3 in the modified glasses led to a prolonged drug release pattern relative to the base glass. The cytotoxicity test against BHK fibroblast cells showed that all phosphate nanoparticles were biocompatible. The viability of incubated cells with PL10 was > 97% suggesting that PL10 was not toxic up to 2.5 mg dose. However, a mild reduction of cell viability (93.3%) occurred at 5 mg, and at this dose, the cell viability increased in the following order P0 → PL5 → PL10, as it was 80, 87.4 and 93.3%. In conclusion, the long-term sustained pattern provided merely by the lanthanum-modified phosphate glasses nanoparticles implied the possibility of their application for localized osteomyelitis treatment.