Previous works applied hydroxyapatite nanoparticles as a drug delivery system. Hydroxyapatite has been manufactured as co-doped Ag/Fe, showing improved efficacy in curing cancer cells by MTT assay in HeLa cells and non-toxicity towards normal cells . By chemically joining the rhEGF-rP64k antigen, the rhEGF, and rP64k proteins in two forms to hydroxyapatite, three novel systems were synthesized that cause no injection site harm while producing an antibody response to EGF in immunized animals . Additionally, hydroxyapatite has been used as a drug delivery system for anti-inflammatory drugs, anti-osteoporotic substances, tissue antibiotics, and other substances such as vitamins, hormones, and proteins . One example is bioceramic composite microneedles fabricated with gelatin and hydroxyapatite to deliver insulin in diabetic rats, showing low cytotoxicity and excellent mechanical properties .