An injectable liposome for sustained release of tanshinone IIA to the treatment of acute blunt muscle injury by augmenting autophagy and alleviating oxidative stress.

Acute blunt skeletal muscle injury occurs frequently in sports and traffic accidents, and even leads to muscle necrosis and impaired functionality. Current treatment options for muscle injuries remain suboptimal and often result in delayed/incomplete recovery of damaged muscles. Tanshinone IIA is extracted from Salvia Miltiorrhizae, which is effective in the treatment of injury repair. But the clinical application of tanshinone IIA is limited due to its low water solubility, low permeability to biofilm and low bioavailability. In this study, tanshinone IIA liposomes were prepared to improve the bioavailability and sustained release of tanshinone IIA. The particle size, dispersion coefficient, zeta potential, encapsulation efficiency (EE) and drug loading (DL) of tanshinone IIA liposomes were 150.67 ± 27.23 nm, 0.20 ± 0.015, -8.73 ± 2.28 mV, 70.32 ± 4.04% and 15.63%, respectively. The results of quantitative real-time polymerase chain reaction (QRT-PCR) showed that tanshinone IIA liposome significantly promoted the expression of vimentin and reduce MHCIIB expression compared with other groups (P < 0.05). Western blotting showed that tanshinone IIA liposome could effectively promote the expression of autophagy-related proteins (VPS34, Beclin 1 and CTSD) and decrease p62 expression levels to treat injured muscle. Through HE, immunohistochemistry, ELISA and serological tests, we found that tanshinone IIA liposome not only effectively promoted the expression of desmin, but also reduced the expression of collagen-I and inhibited the production of pro-inflammatory factors, such as tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) (P < 0.05). In addition, tanshinone IIA liposome therapy significantly reduced the level of malondialdehyde (MDA) and increased the activity of superoxide dismutase (SOD) after muscle injury compared with other groups (P < 0.05). In conclusion, tanshinone IIA liposome possesses an effective therapeutic effect on acute blunt muscle injury in rats by augmenting autophagy and alleviating oxidative stress. The continuous release of tanshinone IIA encapsulated by liposomes for disease treatment provide a new idea for the efficient and safe use of drugs with low lipid solubility and bioavailability for the treatment of acute blunt muscle injury and repair of other injuries. AJTR