Modified Lipid Nanocapsules for Targeted Tanshinone IIA Delivery in Liver Fibrosis

Liver fibrosis represents a serious global disease with no approved treatment. Tanshinone IIA (TSIIA) is a phytomedicine with documented activity in treating many hepatic disorders. TSIIA has been reported to have potent anti-inflammatory and antioxidant properties. It can also induce apoptosis for activated hepatic stellate cells, and is thereby considered as a promising herbal remedy for treating fibrotic liver. However, its poor aqueous solubility, short half-life, exposure to the first-pass effect, and low concentration reaching targeted cells constitute the major barriers hindering its effective therapeutic potential. Therefore, this work aimed at enhancing TSIIA systemic bioavailability together with achieving active targeting potential to fibrotic liver via its incorporation into novel modified lipid nanocapsules (LNCs).

Blank and TSIIA-loaded LNCs modified with either hyaluronate sodium or phosphatidyl serine were successfully prepared, optimized, and characterized both in vitro and in vivo.

The developed LNCs showed good colloidal properties (size ≤100 nm and PDI ≤0.2), high drug-entrapment efficiency (>97%) with sustained-release profile for 24 hours, high storage stability up to 6 months, and good in vitro serum stability. After a single intraperitoneal injection, the administered LNCs exhibited a 2.4-fold significant increase in AUC_0-∞ compared with the TSIIA suspension (p≤0.01). Biodistribution-study results proved the liver-targeting ability of the prepared modified LNCs, with a significant ~1.5-fold increase in hepatic accumulation compared with the unmodified formulation (p≤0.05). Moreover, the modified formulations had an improved antifibrotic effect compared with both unmodified LNCs and TSIIA suspension, as evidenced by the results of biochemical and histopathological evaluation.

The modified TSIIA-LNCs could be regarded as promising novel targeted nanomedicines for effective management of liver fibrosis.