Microcalorimetric studies of the effects of artesunate liposomes on the metabolism of Escherichia coli during growth

A thermal dynamic model of nanoformulations entrapped in artesunate liposomes was established and biological thermodynamics was applied for investigation of the drug formulations. Effects of artesunate liposomes on the growth metabolism of Escherichia coli were studied by microcalorimetry. The results showed that (1) Comparison of artesunate and artesunate liposomes, the thermogenesis curves of E. coli were significant different in the metabolic process: lag phase (AB), log phase (BC), stationary phase (CD), and decline phase (DE); (2) Linear fit of the data of total metabolic heat of E. coli effected by different concentration artesunate (1-300 mu g), the equation can be obtained as follows: Y = 364720.61-1075.25x, R = 0.9985; Linear fit of the data of total metabolic heat of E. coli effected by different concentration artesunate liposomes (30-120 mu g), the linear equation can be obtained as follows: Y = 54251.5765-35.71122x, R = 0.98345; (3) The half inhibitory concentration I-C50 was 50.05 mu g/mL, the relative sensitivity was obviously different; (4) Artesunate liposomes having better sustained release properties as compare to artesunate.