Effect of bone‐like hydroxyapatite/poly amino acid loaded with rifapentine microspheres on bone and joint tuberculosis in vitro

Rifapentine‐loaded poly(lactic‐co‐glycolic acid) microspheres (RPMs)‐loaded bone‐like hydroxyapatite/poly amino acid (BHA/PAA) is effective in curing Staphylococcus aureus ‐induced chronic osteomyelitis. This study continues to investigate the effect of RPM‐loaded BHA/PAA on the bacterial growth of Mycobacterium tuberculosis (MTB), cell proliferation and differentiation in MTB H37Rv‐infected MG63 cells. Furthermore, whether Wnt/β‐catenin signaling pathway was activated by RPM‐loaded BHA/PAA was explored. We found the bactec growth index of H37Rv was significantly inhibited by RPM‐loaded BHA/PAA. The MTT assay showed that RPM‐loaded BHA/PAA could promote the cell proliferation of H37Rv‐infected MG63 cells, as determined by MTT assay. The alkaline phosphatase (ALP) activity and the expression of runt‐related transcription factor 2 (Runx2) and osteocalcin (OCN) was examined by commercial kit and Western blot analysis to determine the effect of RPM‐loaded BHA/PAA on MTB H37Rv‐infected MG63 cell differentiation. It was revealed that RPM‐loaded BHA/PAA could promote cell differentiation of H37Rv‐infected MG63 cells. Furthermore, we found the expression of Wnt1, LDL receptor related protein 6 (Lrp6) and β‐catenin was significantly increased in H37Rv‐infected MG63 cells following treatment with RPM‐loaded BHA/PAA, as determined by Western blot analysis. In conclusion, this study demonstrated that RPM‐loaded BHA/PAA has an effective activity against MTB. RPM‐loaded BHA/PAA promoted cell proliferation and cell differentiation of H37Rv‐infected MG63 cells. Wnt/β‐catenin signaling could be activated by RPM‐loaded BHA/PAA in MG63 cells infected with H37Rv. This study demonstrated the potential value of RPM‐loaded BHA/PAA in treating bone and joint TB, and suggested Wnt/β‐catenin signaling may be an important pathway underlying its function.