Adoptive Transfer of Photosensitizer-Loaded Cytotoxic T Cells for Combinational Photodynamic Therapy and Cancer Immuno-Therapy.

Adoptive cell transfer (ACT) has shown remarkable therapeutic efficacy against blood cancers such as leukemia and lymphomas, but its effect is still limited due to the lack of well-defined antigens expressed by aberrant cells within tumors, the insufficient trafficking of administered T cells to the tumor sites, as well as immunosuppression induced by the tumor microenvironment (TME). In this study, we propose the adoptive transfer of photosensitizer (PS)-loaded cytotoxic T cells for a combinational photodynamic and cancer immunotherapy. Temoporfin (Foscan®), a clinically applicable porphyrin derivative, was loaded into OT-1 cells (PS-OT-1 cells). The PS-OT-1 cells efficiently produced a large amount of reactive oxygen species (ROS) under visible light irradiation in a culture; importantly, the combinational photodynamic therapy (PDT) and ACT with PS-OT-1 cells induced significant cytotoxicity compared to ACT alone with unloaded OT-1 cells. In murine lymphoma models, intravenously injected PS-OT-1 cells significantly inhibited tumor growth compared to unloaded OT-1 cells when the tumor tissues were locally irradiated with visible light. Collectively, this study suggests that combinational PDT and ACT mediated by PS-OT-1 cells provides a new approach for effective cancer immunotherapy.

Evading Doxorubicin-Induced Systemic Immunosuppression Using Ultrasound-Responsive Liposomes Combined with Focused Ultrasound.

Doxorubicin (DOX) is a representative anticancer drug with a unique ability to induce immunogenic cell death of cancer cells. However, undesired toxicity on immune cells has remained a significant challenge, hindering the usage of DOX in cancer immunotherapy. Here, we report a combined therapy to avoid the off-target toxicity of DOX by adapting ultrasound-responsive liposomal doxorubicin and focused ultrasound exposure. Histological analysis demonstrated that the combined therapy induced less hemosiderosis of splenocytes and improved tumor infiltration of cytotoxic T lymphocytes. Additionally, in vivo therapeutic evaluation results indicate that the combined therapy achieved higher efficacy when combined with PD-1 immune-checkpoint blockade therapy by improving immunogenicity.

Self-immolative nanosensitizer for glutathione depletion- assisted sonodynamic therapy.

Background: Despite remarkable advances in sonodynamic therapy (SDT) of cancer, the low reactive oxygen species (ROS) quantum yield of the sonosensitizer remains a critical concern in glutathione (GSH)-overexpressing cancer cells. Methods: For enhanced SDT, we report hydrophilized self-immolative polymer (SIP)-decorated TiO2 nanoparticles (HSIPT-NPs) to achieve on-demand GSH depletion and ROS generation. Results: Upon intracellular delivery of HSIPT-NPs into hydrogen peroxide-rich cancer cells, SIP is degraded through electron transfer to produce GSH-depleting quinone methide, reprogramming GSH high cancer cells into GSH low phenotype. In the presence of ultrasound, compared to conventional TiO2 NPs, HSIPT-NPs induce significantly higher oxidative stress to cancer cells by incapacitating their antioxidant effects. SDT with HSIPT-NPs effectively inhibit tumor growth in mice via the synergistic effects of GSH depletion and ROS generation. Conclusion: On the basis of their ability to reprogram cancer cells, HSIPT-NPs offer considerable potential as a nanosensitizer for enhanced SDT.

Liposome-mediated PD-L1 multivalent binding promotes the lysosomal degradation of PD-L1 for T cell-mediated antitumor immunity.

Immune checkpoint blockade (ICB) has shown remarkable therapeutic efficacy in a variety of cancers. However, patients exhibit unexpectedly low response rates to ICB therapy owing to the unwanted recycling and cellular abundance of PD-L1. Herein, rational design of PD-L1 multivalent binding liposome is investigated through PEGylated liposomes incorporating different ratios of PD-L1 binding peptide. Liposomes incorporating 10 mol% PD-L1 binding peptides (10-PD-L1-Lipo) promote the multivalent binding with PD-L1 on tumor cell surface, which is endocytosed for its trafficking toward the lysosomes instead of the recycling endosomes. Thereby, 10-PD-L1-Lipo leads to a significant PD-L1 degradation that prevents its recycling and cellular abundance compared to anti-PD-L1 antibody, disrupting immune escape mechanism of tumor cells and enhancing T cell-mediated antitumor immunity. Moreover, a clinically applicable doxorubicin (DOX) liposomal formulation is established via drug encapsulation into 10-PD-L1-Lipo. The resulting DOX-PD-L1-Lipo primes tumors via immunogenic chemotherapy by preferential DOX accumulation by the EPR effect and overcomes PD-L1 abundance induced following chemotherapy through multivalent binding-mediated PD-L1 degradation. As a result, the synergistic immunogenic chemotherapy and multivalent binding-mediated PD-L1 degradation by DOX-PD-L1-Lipo show significantly enhanced antitumor efficacy and immune responses in colon tumor models. Collectively, this study suggests the rationally designed PEGylated liposomes to promote PD-L1 multivalent binding providing a new route for safe and more effective ICB therapy.

Dissolving microneedles for long-term storage and transdermal delivery of extracellular vesicles.

Extracellular vesicles (EVs) have shown great potential in disease diagnosis and treatment; however, their clinical applications remain challenging due to their unsatisfactory long-term stability and the lack of effective delivery strategies. In this study, we prepared human adipose stem cell-derived EV (hASC-EV)-loaded hyaluronic acid dissolving microneedles (EV@MN) to investigate the feasibility of EVs for their clinical applications. The biological activities of the EVs in this formulation were maintained for more than six months under mild storage conditions, especially at temperatures lower than 4 °C. Moreover, the EV@MN enabled precise and convenient intradermal delivery for sustained release of EVs in the dermis layer. Therefore, EV@MN significantly improved the biological functions of hASC-EVs on dermal fibroblasts by promoting syntheses of proteins for the extracellular matrix such as collagen and elastin, enhancing fibroblast proliferation, and regulating the phenotype of fibroblast, compared with other administration methods. This research revealed a possible and feasible formulation for the clinical application of EVs.

Light-Activated Monomethyl Auristatin E Prodrug Nanoparticles for Combinational Photo-Chemotherapy of Pancreatic Cancer.

Pancreatic cancer is a highly fatal disease that is becoming an increasingly leading cause of cancer-related deaths. In clinic, the most effective approach to treat pancreatic cancers is the combination treatment of several chemotherapeutic drugs, including fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX), but this approach is not adequate to manage patients due to their severe toxic side effects. Herein, we proposed light-activated monomethyl auristatin E (MMAE) prodrug nanoparticles for combinational photo-chemotherapy and optimized its applications for pancreatic cancer treatment. The photosensitizer (Ce6) and chemotherapeutic drug (MMAE) were conjugated through caspase-3-specific cleavable peptide (KGDEVD). The resulting CDM efficiently promoted the reactive oxygen species (ROS) under visible light irradiation and thereby induced caspase-3 overexpression in pacreatic cancers, which subsequently released the MMAE from the system. Importantly, MMAE released from CDM further amplified the activation of CDM into MMAE by inducing extensive apoptotic cell death in tumor microenvironment for treatment of tumor cells in deep in the tumor tissues as far visible light cannot reach. In addition, CDM formed prodrug nanoparticles via intermolecular π-π stacking and hydrophobic interactions, allowing durable and reliable treatment by preventing fast leakage from the pancreatic cancers via the lymphatic vessels. The CDM directly (intratumoral) injected into pancreatic cancers in orthotopic models through an invasive approach significantly delayed the tumor progression by combinational photo-chemotherapy with less toxic side effects. This study offers a promising and alternative approach for safe and more effective pancreatic cancer treatment via prodrug nanoparticles that combine photodynamic therapy and chemotherapy.

Polymeric Hydrogels for Controlled Drug Delivery to Treat Arthritis.

Rheumatoid arthritis (RA) and osteoarthritis (OA) are disabling musculoskeletal disorders that affect joints and cartilage and may lead to bone degeneration. Conventional delivery of anti-arthritic agents is limited due to short intra-articular half-life and toxicities. Innovations in polymer chemistry have led to advancements in hydrogel technology, offering a versatile drug delivery platform exhibiting tissue-like properties with tunable drug loading and high residence time properties This review discusses the advantages and drawbacks of polymeric materials along with their modifications as well as their applications for fabricating hydrogels loaded with therapeutic agents (small molecule drugs, immunotherapeutic agents, and cells). Emphasis is given to the biological potentialities of hydrogel hybrid systems/micro-and nanotechnology-integrated hydrogels as promising tools. Applications for facile tuning of therapeutic drug loading, maintaining long-term release, and consequently improving therapeutic outcome and patient compliance in arthritis are detailed. This review also suggests the advantages, challenges, and future perspectives of hydrogels loaded with anti-arthritic agents with high therapeutic potential that may alter the landscape of currently available arthritis treatment modalities.

Functional Extracellular Vesicles for Regenerative Medicine.

The unique biological characteristics and promising clinical potential of extracellular vesicles (EVs) have galvanized EV applications for regenerative medicine. Recognized as important mediators of intercellular communication, naturally secreted EVs have the potential, as innate biotherapeutics, to promote tissue regeneration. Although EVs have emerged as novel therapeutic agents, challenges related to the clinical transition have led to further functionalization. In recent years, various engineering approaches such as preconditioning, drug loading, and surface modification have been developed to potentiate the therapeutic outcomes of EVs. Also, limitations of natural EVs have been addressed by the development of artificial EVs that offer advantages in terms of production yield and isolation methodologies. In this review, an updated overview of current techniques is provided for the functionalization of natural EVs and recent advances in artificial EVs, particularly in the scope of regenerative medicine.

Chemiluminescence resonance energy transfer-based immunostimulatory nanoparticles for sonoimmunotherapy.

Sonodynamic therapy (SDT) has recently emerged as a promising alternative to photodynamic therapy because of its applicability in treating deeply located tumors accessible by ultrasound (US). However, the therapeutic potential of conventional sonosensitizers is limited by the low quantum yield of reactive oxygen species (ROS) and poor immune responses eliciting canonical apoptosis of cancer cells. Herein, we report chemiluminescence resonance energy transfer (CRET)-based immunostimulatory nanoparticles (iCRET NPs) for sonoimmunotherapy, which not only amplify the ROS quantum yield of sonosensitizers but also generate carbon dioxide (CO2) bubbles to induce immunogenic cell death in the tumor microenvironment (TME). Owing to their CRET phenomena responsive to H2O2 in the TME, iCRET NPs exhibit strong cytotoxicity to cancer cells by producing a large quantity of ROS. Additionally, iCRET NPs effectively induce CO2-mediated immunogenic cell death by rupturing the cancer cell membrane in the presence of US, leading to the release of bare damage-associated molecular patterns, such as HSP 70 and HMGB1. Consequently, when iCRET NPs are combined with anti-PD-1 antibodies, iCRET NPs exhibit synergistic effects in 4T1 tumor-bearing mice, in which antitumor immunity is remarkably amplified to inhibit tumor growth and metastasis.

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.

Gold-installed hyaluronic acid hydrogel for ultrasound-triggered thermal elevation and on-demand cargo release.

The temporal and quantitative control of the cargo release is a challenging issue in the application of hydrogels for cancer therapy. Here, we report hyaluronic acid hydrogel-based depot that provides ultrasound-triggered thermal elevation and on-demand cargo release. The hyaluronic acid hydrogel was developed by employing the gold cluster as a sonothermal crosslinker which was grown on the cargo to prevent its undesired leakage until ultrasound-induced dissociation. The results demonstrated that, in the presence of ultrasound at 30 W, the hyaluronic acid hydrogel significantly increased the temperature to 53.7 °C, leading to dissociation of gold clusters and subsequent cargo release. In addition, the prepared hydrogel exhibited appropriate mechanical properties and superior biostability as an injectable hydrogel for in vivo applications.

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.

Carboxymethyl dextran-based nanocomposites for enhanced chemo-sonodynamic therapy of cancer.

Glutathione (GSH), a tripeptide abundant in the cancer cells, inhibits the cytotoxic effect of reactive oxygen species (ROS) and is associated with anti-apoptosis, thus facilitating tumor growth. Here, we report GSH-depleting carboxymethyl dextran nanocomposites for chemo-sonodynamic therapy for cancer. The nanocomposite is composed of the TiO2-based core as the sonosensitizer, MnO2 coat as the GSH-consuming chemosensitizer, and carboxymethyl dextran as the hydrophilic shell. The in vitro cell experiments demonstrated that, when taken up by the cancer cells, the nanocomposites can deplete intracellular GSH by reducing MnO2 to Mn2+ which induces intracellular ROS production. Upon exposure to ultrasound, the nanocomposites effectively generated cytotoxic singlet oxygen at the intracellular level, remarkably enhancing the cytotoxicity to cancer cells. Notably, chemo-sonodynamic activity of the nanocomposites induced apoptosis as well as necrosis of cancer cells, implying their high potential as the anticancer therapeutics.

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.

Recent advances in nanomaterial-based augmented sonodynamic therapy of cancer.

With interest in non-invasiveness and safety in cancer treatment, sonodynamic therapy (SDT) has emerged as a promising alternative to conventional cancer therapies. SDT offers safety and cost-effectiveness and exhibits a broad application range that is superior to photodynamic therapy. However, the insufficient reactive oxygen species (ROS) production of current sonosensitizers has hindered its clinical application to date. In this review, the ROS-generation mechanism in SDT and the limitations of current sonosensitizers are briefly reviewed. Also, highlighted are recent nanomaterial-based SDT strategies to improve the efficiency of sonosensitizers, amplify oxidative stress, and elicit antitumor immunity.

Recent Developments in Pathological pH-Responsive Polymeric Nanobiosensors for Cancer Theranostics.

Polymeric nanobiosensors (PNBS) that respond to tumor-related factors, including pH, have shown great potential for disease detection owing to their selectivity and sensitivity. PNBS can be converted into theranostic polymeric nanobiosensors (TPNBS) by incorporating therapeutic cargo, thereby enabling concomitant diagnoses and therapy of targeted diseases. The polymeric compartments in TPNBS play a significant role in the development and therapeutic efficacy of nanobiosensors. Polymers enhance the stability, biocompatibility, and selective or effective accumulation of nanobiosensors at desired pathological sites. The intrinsic pH sensitivity of either the polymers in TPNBS or the TPNBS themselves provides integrated potentialities such as cogent accumulation of TPNBS at the tumor, augmented tumor penetration, cellular uptake, and theranostic activation, including enhanced bioimaging signals and controlled release of therapeutics. In this review, we summarize recent developments in the design, preparation, and characterization of pH-responsive TPNBS and their ability to behave as efficient in vivo nanotheranostic agents in acidic cancer environments.

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.

Cavitation-Inducible Mesoporous Silica-Titania Nanoparticles for Cancer Sonotheranostics.

Sonodynamic therapy has received increasing attention for cancer treatments as an alternative to photodynamic therapy. However, its clinical applications have been limited by the lack of a sonosensitizer that is capable of producing sufficient amounts of reactive oxygen species (ROS) in response to ultrasound (US) exposure. Herein, PEGylated mesoporous silica-titania nanoparticles (P-MSTNs) are prepared and used as US-responsive nanocarriers for cancer sonotheranostics. Perfluorohexane (PFH), which is chosen as the gas precursor, is physically encapsulated into P-MSTNs using the oil-in-water emulsion method. Owing to the vaporization of the gas precursor, PFH@P-MSTNs (137 nm in diameter) exhibit a strong photoacoustic signal in vivo for at least 6 h. Compared to P-MSTNs, PFH@P-MSTNs generate significantly higher amounts of ROS due to the nanobubble-induced cavitation in the presence of US. When systemically administered to tumor-bearing mice, PFH@P-MSTNs effectively accumulate in the tumor site due to the passive targeting mechanism. Consequently, PFH@P-MSTNs show much higher antitumor efficacy than P-MSTNs due to the enhanced cavitation-mediated ROS generation in response to US exposure. It is considered that PFH@P-MSTNs may hold significant potential for cancer sonotheranostics.