Safety studies of polyethylene glycol–hydroxyapatite nanocomposites on Drosophila melanogaster: an in vivo model

Hydroxyapatite Nanoparticle (HAp NPs) is similar to the crystal structure of human bone. It has excellent properties such as biocompatibility, osteoconductivity, and biodegradable. Owing to these properties, it has been used in the field of drug delivery, dental applications, and bone tissue engineering. PEG (Polyethylene glycol) is a synthetic biodegradable polymer. It prevents the agglomeration of the nanoparticles, surface oxidation of the particles and thereby making it more biocompatible. Rose Bengal (RB) is a photo sensitiser which has the ability to generate singlet oxygen. In the present study, PEG/HAp nanocomposite has been synthesised and characterised using DLS and Zeta potential, TEM, and FTIR. The safety efficacy of the PEG/HAp nanocomposite was studied in wild type Drosophila larvae and adult flies after oral administration. Larval crawling assay, negative geotaxis assay, survival assay, biochemical assays—SOD activity, DPPH activity and GSH activity were performed. This study showed that the nanocomposite did not affect the development of the larva rather it enhanced the behavioural and antioxidant activity. In the adult flies, the climbing activity and the survivability patterns were greatly improved. Earlier studies with HAp NPs on the Drosophila model did not enhance behavioural and antioxidant activities whilst in the present study, PEG might help in improving these activities due to its non-immunogenic and non-antigenic properties.