Remodeling Collagen Microenvironment in Liver Using a Biomimetic Nano-Regulator for Reversal of Liver Fibrosis

Engineered Stem Cell Booster Breaks Pathological Barriers to Treat Chronic Pancreatitis

Chronic pancreatitis (CP) is a long-standing progressive fibrosis and has long been considered incurable, which remains a heavy health burden worldwide. Mesenchymal stem cells (MSCs) with anti-fibrosis properties are currently used in the treatment of fibroinflammatory diseases. However, its therapeutic effect is limited mainly due to two main types of pathological barriers in CP: 1) Fibrotic collagen hinders cell delivery, and 2) Malignant microenvironment attacks cell inactivation. Here, a MSCs-based exogenous nitric oxide (NO) delivery system (MSCs-Lip@RNO) is constructed. In the MSCs-Lip@RNO, NO not only can be a cell booster to regulate collagen fibers, relieve the vascular compression and enhance the accumulation of MSCs in the whole pancreas, but also can form a protective gas layer on the cell surface, which enhances the therapeutic effect of MSCs. In the CP rat model, the pancreatic injury and fibrosis are reduced with 7 days after a single dose administration of this long-acting MSCs. Collectively, this study offers a promising strategy for enhancing the delivery and therapeutic efficacy of MSCs to break pathological barriers in CP treatment.

Trojan Horse Strategy for Wireless Electrical Stimulation-Induced Zn2+ Release to Regulate Neural Stem Cell Differentiation for Spinal Cord Injury Repair

Due to the uncertain differentiation of neural stem cells (NSCs), replenishing lost neurons by endogenous neural differentiation to repair spinal cord injury (SCI) remains challenging. The electrical stimulation-induced drug release is a promising approach for the localized and controlled release of drugs to regulate the differentiation of NSCs into neurons. Here, we developed Zn-PDA@BT nanoparticles acted as Trojan Horse to enter cells through endocytosis for Zn2+-controlled release therapy by the potentials generated by the piezoelectric effect. Due to the presence of polydopamine (PDA), under ultrasound stimulation, the electrical signal derived from the piezoelectric effect of barium titanate nanoparticles can be attracted to the surface of Trojan Horse nanoparticles to facilitate the controlled release of Zn2+. And Zn2+ bonded with PDA can increase the intracellular Zn2+ concentration within mouse-derived NSCs (mNSCs) to regulate the differentiation of mNSCs, which could enhance excitatory neuronal differentiation and inhibit astrocyte differentiation of mNSCs by activating the TGF-β and p53 pathways. More importantly, this Trojan Horse therapy allowed mNSCs to differentiate into mature neurons in 5 days, while the natural differentiation process took 10 days. Moreover, the transplantation of mNSC-ingested Zn-PDA@BT nanoparticles effectively replenished lost neurons at the damaged site and promoted function recovery after SCI in vivo, demonstrating the great potential of electrical stimulation-induced Zn2+ release for SCI repair.

Berberine-Loaded PVCL-PVA-PEG Self-Assembled Micelles for the Treatment of Liver Fibrosis

Background

Liver fibrosis is a necessary pathological process in many chronic liver diseases. Studies have shown that the progression of chronic liver disease can be slowed by rational intervention in hepatic fibrosis. Berberine (BBR), a natural extract of Phellodendron amurense, inhibits the development of liver fibrosis through several mechanisms. However, the clinical application of BBR is limited due to its low solubility. Drug delivery systems have been developed to improve the solubility of hydrophobic drugs and increase their efficacy in treating the liver fibrosis.

Methods

In this study, a biocompatible nanomicelle was constructed by thin-film dispersion method using polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (PVCL-PVA-PEG) as a carrier to encapsulate BBR (PVCL-PVA-PEG/BBR-MCs) to improve the solubility of BBR and reduce the systemic side effects. The ability to inhibit HSC-T6 cell activation of PVCL-PVA-PEG/BBR-MCs was evaluated in vitro. The anti-hepatic fibrosis effects of PVCL-PVA-PEG/BBR-MCs were investigated in vivo.

Results

PVCL-PVA-PEG/BBR-MCs have a uniform spherical shape with a mean particle size of 60.04 ± 0.027 nm and a potential of 1.49 ± 0.32 mV. It had an encapsulation efficiency of 98.52% ± 0.70 and drug loading content of 6.16% ± 0.04. Compared to free BBR, PVCL-PVA-PEG/BBR-MCs significantly inhibited HSC-T6 cell activation and TGF-β1-induced HSC-T6 cell migration in vitro. In vivo biodistribution experiments showed significantly improved hepatic distribution of PVCL-PVA-PEG/DiD-MCs compared to free DiD, suggesting that PVCL-PVA-PEG micelles enhance the ability of BBR to enter the liver and improve therapeutic efficacy. After treatment, PVCL-PVA-PEG/BBR-MCs significantly improved fibrotic liver structure and reduced collagen deposition in comparison to the CCl4-treated group; the treatment outcome was more effective than that of the free BBR group.

Conclusion

Our results demonstrate the advantages of encapsulating BBR in PVCL-PVA-PEG micelles and highlight the potential of PVCL-PVA-PEG/BBR-MCs as a therapeutic strategy for the treatment of liver fibrosis.

Hepatic stellate cell-targeted chemo-gene therapy for liver fibrosis using fluorinated peptide-lipid hybrid nanoparticles

Exploring precise and effective treatments for liver fibrosis is urgent. The effective therapy for liver fibrosis depends on the specific delivery of antifibrotic drugs to activated hepatic stellate cells (aHSCs). However, this is a challenging task due to pathological barriers, primarily caused by collagen deposition. This study developed vitamin A-functionalized fluorinated peptide/lipid hybrid nanoparticles to co-deliver sorafenib and siRNA against HSP47 (SF-siHSP47@VFPL NPs). This nanoparticle formulation offers significant advantages due to its fluorine‑fluorine and electrostatic interactions, allowing for high SF and siHSP47 loading efficiency and sustained drug release. Importantly, in vitro cell uptake and in vivo biodistribution revealed that VA functionalization significantly improved aHSC-targeted delivery efficiency by engaging retinol-binding protein receptors on HSCs. Furthermore, it dramatically reduced extracellular matrix deposition, as evidenced by diminished levels of liver fibrosis-associated genes (HSP47, TIMP-1, and collagen I), promoting collagen breakdown and preventing collagen production, thus overcoming drug delivery barriers. Thus, SF-siHSP47@VFPL NPs demonstrated optimal antifibrotic effects by triggering apoptosis and ferroptosis in aHSCs. In liver fibrosis mouse models, SF-siHSP47@VFPL NPs remodeled the pathological environment and restored liver functionality through a marked reduction in serum liver transferases, hydroxyproline content, collagen deposition, and α-SMA and CD31 expression in liver tissue, resulting in alleviated liver fibrosis. Consequently, SF-siHSP47@VFPL NPs showed significant potential for HSC-targeted, chemo-gene therapy in the treatment of liver fibrosis.

Delivery Strategy to Enhance the Therapeutic Efficacy of Liver Fibrosis via Nanoparticle Drug Delivery Systems

Liver fibrosis (LF) is a pathological repair reaction caused by a chronic liver injury that affects the health of millions of people worldwide, progressing to life-threatening cirrhosis and liver cancer without timely intervention. Due to the complexity of LF pathology, multiple etiological characteristics, and the deposited extracellular matrix, traditional drugs cannot reach appropriate targets in a time-space matching way, thus decreasing the therapeutic effect. Nanoparticle drug delivery systems (NDDS) enable multidrug co-therapy and develop multifactor delivery strategies targeting pathological processes, showing great potential in LF therapy. Based on the pathogenesis and the current clinical treatment status of LF, we systematically elucidate the targeting mechanism of NDDS used in the treatment of LF. Subsequently, we focus on the progress of drug delivery applications for LF, including combined delivery for the liver fibrotic pathological environment, overcoming biological barriers, precise intracellular regulation, and intelligent responsive delivery for the liver fibrotic microenvironment. We hope that this review will inspire the rational design of NDDS for LF in the future in order to provide ideas and methods for promoting LF regression and cure.

Engineered liposomes targeting hepatic stellate cells overcome pathological barriers and reverse liver fibrosis

Dual pathological barriers, including capillarized liver sinusoidal endothelial cells (LSECs) and deposited extracellular matrix (ECM), result in insufficient drug delivery, significantly compromising the anti-fibrosis efficacy. Additionally, excessive reactive oxygen species (ROS) in the hepatic microenvironment are crucial factors contributing to the progression of liver fibrosis. Hence, hyaluronic acid (HA) modified liposomes co-delivering all-trans retinoic acid (RA) and L-arginine (L-arg) were constructed to reverse hepatic fibrosis. By exhibiting exceptional responsiveness to the fibrotic microenvironment, our cleverly constructed liposomes efficiently disrupted the hepatic sinus pathological barrier, leading to enhanced accumulation of liposomes in activated hepatic stellate cells (HSCs) and subsequent induction of HSCs quiescence. Specially, excessive ROS in liver fibrosis promotes the conversion of loaded L-arg to nitric oxide (NO). The ensuing NO serves to reestablish the fenestrae structure of capillarized LSECs, thereby augmenting the likelihood of liposomes reaching the hepatic sinus space. Furthermore, subsequent oxidation of NO by ROS into peroxynitrite activates pro-matrix metalloproteinases into matrix metalloproteinases, which further disrupts the deposited ECM barrier. Consequently, this NO-induced cascade process greatly amplifies the accumulation of liposomes within activated HSCs. More importantly, the released RA could induce quiescence of activated HSCs by significantly downregulating the expression of myosin light chain-2, thereby effectively mitigating excessive collagen synthesis and ultimately leading to the reversal of liver fibrosis. Overall, this integrated systemic strategy has taken a significant step forward in advancing the treatment of liver fibrosis.