Construction of injectable, pH sensitive, antibacterial, mineralized amino acid yolk-shell microspheres for potential minimally invasive treatment of bone infection.

INTRODUCTION

Treatment of infection within bone is difficult, and conventional surgical treatment brings intense pain to the patients physically and mentally. There is an urgent need to develop injectable nano- and/or micro-medicine for minimally invasive treatment of osteomyelitis.

METHODS

In this paper, amino acid (L-lysine [Lys]) was mineralized into yolk-shell structured CaCO microspheres (MSs). The morphologies of the obtained MSs were investigated by scanning electron microscopy and transmission electron microscopy. The composition of CaCO MSs was identified by using Fourier transform infrared spectroscopy. The as-prepared CaCO MSs were examined with power X-ray diffraction analysis to obtain the crystallographic structure of the MSs.

RESULTS

The as prepared Lys encapsulated CaCO MSs (Lys@CaCO MSs) were used as micro-drug to improve acidic environment of osteomyelitis caused by bacterial infection and promote osteoblast proliferation under oxidative stress. These pH responsive Lys@CaCO MSs have a drug loading efficiency of 89.8 wt % and drug loading content (DLC) of 22.3 wt %.

CONCLUSION

Our results demonstrated that Lys@CaCO MSs can effectively kill and promote proliferation and differentiation of osteoblasts under stimulation of HO at pH = 5.5.