Stem Cell-Derived Extracellular Vesicle-Bearing Dermal Filler Ameliorates the Dermis Microenvironment by Supporting CD301b-Expressing Macrophages.

Hyaluronic acid-based hydrogels (Hyal-Gels) have the potential to reduce wrinkles by physically volumizing the skin. However, they have limited ability to stimulate collagen generation, thus warranting repeated treatments to maintain their volumizing effect. In this study, stem cell-derived extracellular vesicle (EV)-bearing Hyal-Gels (EVHyal-Gels) were prepared as a potential dermal filler, ameliorating the dermis microenvironment. No significant differences were observed in rheological properties and injection force between Hyal-Gels and EVHyal-Gels. When locally administered to mouse skin, Hyal-Gels significantly extended the biological half-life of EVs from 1.37 d to 3.75 d. In the dermis region, EVHyal-Gels induced the overexpression of CD301b on macrophages, resulting in enhanced proliferation of fibroblasts. It was found that miRNAs, such as let-7b-5p and miR-24-3p, were significantly involved in the change of macrophages toward the CD301bhi phenotype. The area of the collagen layer in EVHyal-Gel-treated dermis was 2.4-fold higher than that in Hyal-Gel-treated dermis 4 weeks after a single treatment, and the collagen generated by EVHyal-Gels was maintained for 24 weeks in the dermis. Overall, EVHyal-Gels have the potential as an antiaging dermal filler for reprogramming the dermis microenvironment.

An anti-DR5 antibody-curcumin conjugate for the enhanced clearance of activated hepatic stellate cells.

Anti-death receptor 5 (DR5) antibody is a potential therapeutic agent for liver fibrosis because it exhibits anti-fibrotic effects by inducing the apoptosis of activated hepatic stellate cells (HSCs), which are responsible for hepatic fibrogenesis. However, the clinical applications of anti-DR5 antibodies have been limited by their low agonistic activity against DR5. In this study, an anti-DR5 antibody-curcumin conjugate (DCC) was prepared to investigate its effect on the clearance of activated HSCs. The DCC was synthesized through a coupling reaction between a maleimide-functionalized curcumin derivative and a thiolated anti-DR5 antibody. No significant differences were observed in the uptake behaviors of activated HSCs between the bare anti-DR5 antibodies and DCC. Owing to the antioxidant and anti-inflammatory effects of curcumin, DCC-treated HSCs produced much lower levels of reactive oxygen species and inducible nitric oxide synthase than the bare anti-DR5 antibody-treated HSCs. Additionally, the anti-fibrotic effects of DCC on activated HSCs were more prominent than those of the bare anti-DR5 antibodies, as demonstrated by the immunocytochemical analysis of α-smooth muscle actin. DCC preferentially accumulated in the liver after its systemic administration to mice with liver fibrosis. Thus, DCC may serve as a potential therapeutic agent for treating liver fibrosis.

Vitamin A-coupled stem cell-derived extracellular vesicles regulate the fibrotic cascade by targeting activated hepatic stellate cells in vivo.

Allogeneic transplantation of mesenchymal stem cell-derived extracellular vesicles (EVs) offers great potential for treating liver fibrosis. However, owing to their intrinsic surface characteristics, bare EVs are non-specifically distributed in the liver tissue after systemic administration, leading to limited therapeutic efficacy. To target activated hepatic stellate cells (HSCs), which are responsible for hepatic fibrogenesis, vitamin A-coupled small EVs (V-EVs) were prepared by incorporating vitamin A derivative into the membrane of bare EVs. No significant differences were found in the particle size and morphology between bare and V-EVs. In addition, surface engineering of EVs did not affect the expression of surface marker proteins (e.g., CD63 and CD9), as demonstrated by flow cytometry. Owing to the surface incorporation of vitamin A, V-EVs were selectively taken up by activated HSCs via receptor-mediated endocytosis. When systemically administered to mice with liver fibrosis, V-EVs effectively targeted activated HSCs in the liver tissue, resulting in reversal of the fibrotic cascade. Consequently, even at a 10-fold lower dose, V-EVs exhibited comparable anti-fibrotic effects to those of bare EVs, substantiating their therapeutic potential for liver fibrosis.

Metabolically engineered stem cell-derived exosomes to regulate macrophage heterogeneity in rheumatoid arthritis.

Despite the remarkable advances in therapeutics for rheumatoid arthritis (RA), a large number of patients still lack effective countermeasures. Recently, the reprogramming of macrophages to an immunoregulatory phenotype has emerged as a promising therapeutic strategy for RA. Here, we report metabolically engineered exosomes that have been surface-modified for the targeted reprogramming of macrophages. Qualified exosomes were readily harvested from metabolically engineered stem cells by tangential flow filtration at a high yield while maintaining their innate immunomodulatory components. When systemically administered into mice with collagen-induced arthritis, these exosomes effectively accumulated in the inflamed joints, inducing a cascade of anti-inflammatory events via macrophage phenotype regulation. The level of therapeutic efficacy obtained with bare exosomes was achievable with the engineered exosomes of 10 times less dose. On the basis of the boosted nature to reprogram the synovial microenvironment, the engineered exosomes display considerable potential to be developed as a next-generation drug for RA.

Bioorthogonally surface-edited extracellular vesicles based on metabolic glycoengineering for CD44-mediated targeting of inflammatory diseases.

Extracellular vesicles (EVs) are essential mediators in intercellular communication that have emerged as natural therapeutic nanomedicines for the treatment of intractable diseases. Their therapeutic applications, however, have been limited by unpredictable in vivo biodistribution after systemic administration. To control the in vivo fate of EVs, their surfaces should be properly edited, depending on the target site of action. Herein, based on bioorthogonal copper-free click chemistry (BCC), surface-edited EVs were prepared by using metabolically glycoengineered cells. First, the exogenous azide group was generated on the cellular surface through metabolic glycoengineering (MGE) using the precursor. Next, PEGylated hyaluronic acid, capable of binding specifically to the CD44-expressing cells, was labelled as the representative targeting moiety onto the cell surface by BCC. The surface-edited EVs effectively accumulated into the target tissues of the animal models with rheumatoid arthritis and tumour, primarily owing to prolonged circulation in the bloodstream and the active targeting mechanism. Overall, these results suggest that BCC combined with MGE is highly useful as a simple and safe approach for the surface modification of EVs to modulate their in vivo fate.

Engineering approaches for effective therapeutic applications based on extracellular vesicles.

The biological significance of extracellular vesicles (EVs) as intercellular communication mediators has been increasingly revealed in a wide range of normal physiological processes and disease pathogenesis. In particular, regenerative and immunomodulatory EVs hold potential as innate biotherapeutics, whereas pathological EVs are considered therapeutic targets for inhibiting their bioactivity. Given their ability to transport functional cargos originating from the source cells to target cells, EVs can also be used as a therapeutic means to deliver drug molecules. This review aims to provide an updated overview of the key engineering approaches for better exploiting EVs in disease intervention. The emphasis is lying on the preconditioning methods for therapeutic EVs, drug loading and targeting technologies for carrier EVs, and activity control strategies for pathological EVs.

Hyaluronic Acid Nanoparticles as Nanomedicine for Treatment of Inflammatory Diseases.

Owing to their unique biological functions, hyaluronic acid (HA) and its derivatives have been explored extensively for biomedical applications such as tissue engineering, drug delivery, and molecular imaging. In particular, self-assembled HA nanoparticles (HA-NPs) have been used widely as target-specific and long-acting nanocarriers for the delivery of a wide range of therapeutic or diagnostic agents. Recently, it has been demonstrated that empty HA-NPs without bearing any therapeutic agent can be used therapeutically for the treatment of inflammatory diseases via modulating inflammatory responses. In this review, we aim to provide an overview of the significant achievements in this field and highlight the potential of HA-NPs for the treatment of inflammatory diseases.

Human adipose stem cell-derived extracellular nanovesicles for treatment of chronic liver fibrosis.

Liver fibrosis is an excessive wound healing process that occurs in response to liver damage depending on underlying aetiologies. Currently, there are no effective therapies and FDA-approved therapeutics for the treatment of liver fibrosis except liver transplantation. Multipotent adipose-derived stem cells (ADSCs) have received significant attention as regenerative medicine for liver fibrosis owing to their advantages over stem cells with other origins. However, intrinsic limitations of stem cell therapies, such as cellular rejection and tumor formation, have impeded clinical applications of the ADSC-based liver therapeutics. To overcome these problems, the extracellular nanovesicles (ENVs) responsible for the therapeutic effect of ADSCs (A-ENVs) have shown considerable promise as cell-free therapeutics for liver diseases. However, A-ENVs have not been used for the treatment of intractable chronic liver diseases including liver fibrosis and cirrhosis. Therefore, in this study, we investigated the in vitro and in vivo antifibrotic efficacy of A-ENVs in thioacetamide-induced liver fibrosis models. A-ENVs significantly downregulated the expression of fibrogenic markers, such as matrix metalloproteinase-2, collagen-1, and alpha-smooth muscle actin. The systemic administration of A-ENVs led to high accumulation in fibrotic liver tissue and the restoration of liver functionality in liver fibrosis models through a marked reduction in α-SMA and collagen deposition. These results demonstrate the significant potential of A-ENVs for use as extracellular nanovesicles-based therapeutics in the treatment of liver fibrosis and possibly other intractable chronic liver diseases.