RESUMEN
Preventing hepatic stellate cell (HSC) activation represents a promising approach to resolve liver fibrosis. Several drugs have been reported to delay/prevent HSCs activation, however with limited clinical benefits. The latter may be in part attributed to the limited ability of such drugs in targeting more than one pathway of HSC activation. Added to that, is their inability of reaching their target cell in sufficient amounts to induce a therapeutic effect. In this work, chitosan NPs were loaded with JQ1 and atorvastatin, two drugs that have been reported to prevent HSCs activation, however via different mechanisms. NPs were then modified with different densities of retinol (Rt) for active targeting of HSCs. The NP HSCs targeting ability as a function of Rt density was assessed in vitro on primary HSCs and in vivo in carbon tetrachloride (CCl4) induced fibrotic mouse models. In vitro NPs modified with a low Rt density (LRt-NPs) showed ≈2 folds enhanced HSCs uptake in comparison to unmodified NPs, whereas NPs modified with a high Rt density (HRt-NPs) showed ≈0.8 folds change in uptake relative to unmodified NPs. Similarly, in vivo LRt-NPs showed higher accumulation in fibrotic livers in comparison to healthy livers whereas HRt-NPs and unmodified NPs showed lower accumulation in fibrotic livers relative to healthy controls respectively. Finally, the ability of drug-loaded NPs in preventing HSCs activation was assessed by monitoring the reduction in α-smooth muscle actin (α-SMA) expression by Western blot. NPs loaded with both JQ1 and atorvastatin showed reduction in α-SMA expression. In addition, a synergistic reduction in α-SMA was observed when cells were co-treated with JQ1 and atorvastatin loaded NPs.