Biomimetic hydroxyapatite as potential polymeric nanocarrier for the treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease of unknown etiology with much higher prevalence in world's population. RA is initially associated with inflammation of joints and cartilages that ultimately leads to their destruction thus requiring a therapeutic intervention. The available conventional therapeutic strategies for RA are not satisfactory because of the associated side effects such as toxicity, delayed action, and dependence. Therefore, a carrier system is required that should deliver the drug to the target site with minimal side effects. In this connection, nanocarrier systems are of prime importance because of the associated benefits such as their nano-scaled size, targeted drug delivery, and reduced toxicity that can improve the patient's compliance. Moreover, in the past few decades, nano-particulate-based drug delivery approaches that have been investigated for the treatment of RA include ceramics, polymers, and hydrogels. Among these nanocarrier systems, ceramics like hydroxyapatite have gathered striking attention due to their bioactive, biocompatible, and bio-conductive characteristics. Nano-sized hydroxyapatite (HA) permeates the bone tissues and serves as a source of calcium phosphates required for bone repairing that are damaged during disease process. The aim of this review article is to highlight the potential use of HA as nanocarrier for anti-rheumatic drugs as well its possible effect on bone remodeling.