Evaluation of antibacterial activity of nano-hydroxyapatite (HAp) from freshwater mussel (Pilsbryoconcha sp.) shell against Escherichia coli

Abstract

Freshwater mussel shells have a high calcium content as a precursor in the synthesis of hydroxyapatite (HAp). The main components of HAp are calcium and phosphate, which can prevent dental plaque bacteria, such as Escherichia coli. This research aimed to evaluate the antibacterial activity of nano-hydroxyapatite (nano-HAp) from Pilsbryoconcha sp. against E. coli. The procedure for preparing nano-HAp consisted of producing CaO flour through a calcination process and producing nano-HAp using the bottom up method. The test parameters consisted of the yield and evaluation of antibacterial activity at different concentrations of nano-HAp, namely 50 mg/mL, 25 mg/mL, and 12.5 mg/mL. The results showed that the yield of nano-HAp was 65.13±0.83%. Based on antibacterial activity, nano-HAp had an inhibition zone against the bacteria that causes dental plaque E. coli. The diameters of the inhibition zones of nano-HAp against E. coli bacteria at concentration of 12.5 mg/mL, 25 mg/mL, and 50 mg/mL were relatively weak, those were 1.23±0.31 mm, 2.51±0.38 mm, and 3.77±0.28 mm, respectively. The antibacterial activity of nano-HAp can be increased through modification with metal doping or natural materials with antioxidant or antibacterial activity.