Photodynamic therapy with the dual-mode association of IR780 to PEG-PLA nanocapsules and the effects on human breast cancer cells

Enhanced Intracellular IR780 Delivery by Acidity-Triggered PEG-Detachable Hybrid Nanoparticles to Augment Photodynamic and Photothermal Combination Therapy for Melanoma Treatment

The PEGylation of drug-carrying nanoparticles has often been used to prolong blood circulation and improve drug deposition at tumor sites. Nevertheless, the PEG-rich hydrophilic surfaces retard the release of the payloads and internalization of therapeutic nanoparticles by cancer cells, thus lowering the anticancer efficacy. To boost the anticancer potency of the combined photodynamic therapy (PDT) and photothermal therapy (PTT) against melanoma by conquering the PEG dilemma, herein, the hybrid PEGylated chitosan-covered polydopamine (PDA) nanoparticles (PCPNs) with acidity-elicited PEG detachment ability were fabricated as carriers of IR780, a small-molecule photosensitizer used for PTT and PDT. The IR780@PCPNs displayed a uniform, solid-like spherical shape and sound colloidal stability. Under near-infrared (NIR) irradiation, the IR780@PCPNs showed prominent photothermal conversion efficiency (ca. 54.6%), robust photothermal stability, reduced IR780 photobleaching, sufficient singlet oxygen (1O2) production, and glutathione-depleting ability. Moreover, with the environmental pH being reduced from 7.4 to 5.0 at 37 °C, the decreased interactions between IR780 and PCPNs due to the increased protonation of phenolic hydroxyl residues within PDA and primary amine groups of chitosan accelerated the release of IR780 species from IR780@PCPNs. Importantly, the cellular uptake of IR780@PCPNs by B16F10 melanoma was remarkably promoted in a weakly acidic milieu upon PEG detachment driven by the disintegration of acid-labile benzoic imine. With NIR irradiation, the internalized IR780@PCPNs generated hyperthermia and 1O2 to damage mitochondria, thereby effectively inhibiting the proliferation of B16F10 cells. Collectively, our findings present a practical strategy for amplifying the anticancer efficacy of PTT combined with PDT using PEG-detachable IR780@PCPNs.

Multi-pathway oxidative stress amplification via controllably targeted nanomaterials for photoimmunotherapy of tumors

Photoimmunotherapy, which combines phototherapy with immunotherapy, exhibits significantly improved therapeutic effects compared with mono-treatment regimens. However, its use is associated with drawbacks, such as insufficient reactive oxygen species (ROS) production and uneven photosensitizer distribution. To address these issues, we developed a controllable, targeted nanosystem that enhances oxidative stress through multiple pathways, achieving synergistic photothermal, photodynamic, and immunotherapy effects for tumor treatment. These nanoparticles (D/I@HST NPs) accurately target overexpressed transferrin receptors (TfRs) on the surface of tumor cells through surface-modified transferrin (Tf). After endocytosis, D/I@HST NPs generate ROS under 808-nm laser irradiation, breaking the ROS-responsive crosslinking agent and increasing drug release and utilization. Tf also carries Fe3+, which is reduced to Fe2+ by iron reductase in the acidic tumor microenvironment (TME). Consequently, the endoperoxide bridge structure in dihydroartemisinin is cleaved, causing additional ROS generation. Furthermore, the released IR-780 exerts both photodynamic and photothermal effects, enhancing tumor cell death. This multi-pathway oxidative stress amplification and photothermal effect can trigger immunogenic cell death in tumors, promoting the release of relevant antigens and damage-associated molecular patterns, thereby increasing dendritic cell maturation and sensitivity of tumor cells to immunotherapy. Mature dendritic cells transmit signals to T cells, increasing T cells infiltration and activation, facilitating tumor growth inhibition and the suppression of lung metastasis. Furthermore, the myeloid-derived suppressor cells in the tumor decreases significantly after treatment. In summary, this multi-pathway oxidative stress-amplified targeted nanosystem effectively inhibits tumors, reverses the immunosuppressive tumor microenvironment, and provides new insights into tumor immunotherapy combined with phototherapy.

Nitroreductase-Responsive Fluorescent "Off-On" Photosensitizer for Hypoxic Tumor Imaging and Dual-Modal Therapy

Photothermal therapy synergized with photodynamic therapy for the treatment of tumors has emerged as a promising strategy. However, designing photosensitizers with both high photothermal efficiency and high photodynamic performance remains challenging. In contrast, the strategy of rationalizing the design of photosensitizers using the physiological properties of tumors to improve the photon utilization of photosensitizers during phototherapy is more advantageous than the approach of endowing a single photosensitizer with complex functions. Herein, we propose a molecular design (CyNP) to convert from photothermal therapy to photodynamic synergistic photothermal therapy based on the prevalent properties of hypoxic tumors. In the normoxic region of tumors, the deactivation pathway of CyNP excited state is mainly the conversion of photon energy to thermal energy; in the hypoxic region of tumors, CyNP is reduced to CyNH by nitroreductase, and the deactivation pathway mainly includes radiation leap, energy transfer between CyNP and oxygen, and conversion of photons energy to heat energy. This strategy enables real-time fluorescence detection of hypoxic tumors, and it also provides dual-mode treatment for photothermal and photodynamic therapy of tumors, achieving good therapeutic effects in vivo tumor treatment. Our study achieves more efficient tumor photoablation and provides a reference for the design ideas of smart photosensitizers.

Combination Nano-Delivery Systems Remodel the Immunosuppressive Tumor Microenvironment for Metastatic Triple-Negative Breast Cancer Therapy

Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer for which effective therapies are lacking. Targeted remodeling of the immunosuppressive tumor microenvironment (TME) and activation of the body's immune system to fight tumors with well-designed nanoparticles have emerged as pivotal breakthroughs in tumor treatment. To simultaneously remodel the immunosuppressive TME and trigger immune responses, we designed two potential therapeutic nanodelivery systems to inhibit TNBC. First, the bromodomain-containing protein 4 (BRD4) inhibitor JQ1 and the cyclooxygenase-2 (COX-2) inhibitor celecoxib (CXB) were coloaded into chondroitin sulfate (CS) to obtain CS@JQ1/CXB nanoparticles (NPs). Then, the biomimetic nanosystem MM@P3 was prepared by coating branched polymer poly(β-amino ester) self-assembled NPs with melittin embedded macrophage membranes (MM). Both in vitro and in vivo, the CS@JQ1/CXB and MM@P3 NPs showed excellent immune activation efficiencies. Combination treatment exhibited synergistic cytotoxicity, antimigration ability, and apoptosis-inducing and immune activation effects on TNBC cells and effectively suppressed tumor growth and metastasis in TNBC tumor-bearing mice by activating the tumor immune response and inhibiting angiogenesis. In summary, this study offers a novel combinatorial immunotherapeutic strategy for the clinical TNBC treatment.

Drug repurposing-based nanoplatform via modulating autophagy to enhance chemo-phototherapy against colorectal cancer

Multi-modal combination therapy is regarded as a promising approach to cancer treatment. Combining chemotherapy and phototherapy is an essential multi-modal combination therapy endeavor. Ivermectin (IVM) is a potent antiparasitic agent identified as having potential antitumor properties. However, the fact that it induces protective autophagy while killing tumor cells poses a challenge to its further application. IR780 iodide (IR780) is a near-infrared (NIR) dye with outstanding photothermal therapy (PTT) and photodynamic therapy (PDT) effects. However, the hydrophobicity, instability, and low tumor uptake of IR780 limit its clinical applications. Here, we have structurally modified IR780 with hydroxychloroquine, an autophagy inhibitor, to synthesize a novel compound H780. H780 and IVM can form H780-IVM nanoparticles (H-I NPs) via self-assembly. Using hyaluronic acid (HA) to modify the H-I NPs, a novel nano-delivery system HA/H780-IVM nanoparticles (HA/H-I NPs) was synthesized for chemotherapy-phototherapy of colorectal cancer (CRC). Under NIR laser irradiation, HA/H-I NPs effectively overcame the limitations of IR780 and IVM and exhibited potent cytotoxicity. In vitro and in vivo experiment results showed that HA/H-I NPs exhibited excellent anti-CRC effects. Therefore, our study provides a novel strategy for CRC treatment that could enhance chemo-phototherapy by modulating autophagy.

Nanocarrier systems loaded with IR780, iron oxide nanoparticles and chlorambucil for cancer theragnostics

Theragnostics has become a popular term nowadays, since it enables both diagnosis and therapy at the same time while only using one carrier platform. Therefore, formulating a nanocarrier system that could serve as theragnostic agent by using simple techniques would be an advantage during production. In this project, we aimed to develop a nanocarrier that can be loaded with the chemotherapeutic medication chlorambucil and magnetic resonance imaging agents (e.g., iron oxide nanoparticles and near-infrared fluorophore IR780) for theragnostics. Poly(lactic-co-glycolic acid) was combined with the aforementioned ingredients to generate poly(vinyl alcohol)-based nanoparticles (NPs) using the single emulsion technique. Then the NPs were coated with F127 and F127-folate by simple incubation for five days. The nanoparticles have the hydrodynamic size of approx. 250 nm with negative charge. Similar to chlorambucil and IR780, iron oxide loadings were observed for all three kinds of NPs. The release of chlorambucil was quicker at pH 5.4 than at pH 7.4 at 37 °C. The F127@NPs and F127-folate@NPs demonstrated much greater cell uptake and toxicity up to 72 h after incubation. Our in vitro results of F127@NPs and F127-folate@NPs have demonstrated the ability of these systems to serve as medication and imaging agent carriers for cancer treatment and diagnostics, respectively.

Photoresponsive 'chemo-free' phytotherapy: formulation development for the treatment of triple-negative breast cancer

Aim: The present investigation aimed to develop a chemo-free, nanophytosomal system to treat triple-negative breast cancer (TNBC) via a phyto-photo dual treatment strategy. Method: Size, shape, surface analysis, photoprovoked release profile, photothermal stability, (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide assay, apoptotic assay, DNA fragmentation, in vitro cellular uptake evaluation, mitochondrial membrane potential and caspase-3 assay, and photodynamic evaluation. Results: Biological experiments using MDA-MB-231 cells displayed dose-dependent synergistic anti-TNBC activity of PhytoS/Houttuynia cordata extract (HCE)/IR780 as compared with Phyto/HCE, PhytoS/IR780 and even more promising under laser treatment. Apoptotic assay and DNA fragmentation analysis also showed enhanced anti-TNBC effects. Investigation found that HCE acts via suppression of mitochondrial membrane potential and inducing caspase-3 activity in cells. Conclusion: Our findings suggested that photo-empowered phytotherapy can be employed effectively and safely against TNBC.

Dual Stimuli-Responsive Micelles for Imaging-Guided Mitochondrion-Targeted Photothermal/Photodynamic/Chemo Combination Therapy-Induced Immunogenic Cell Death

Introduction

As the special modality of cell death, immunogenic cell death (ICD) could activate immune response. Phototherapy in combination with chemotherapy (CT) is a particularly efficient tumor ICD inducing method that could overcome the defects of monotherapies.

Methods

In this study, new dual stimuli-responsive micelles were designed and prepared for imaging-guided mitochondrion-targeted photothermal/photodynamic/CT combination therapy through inducing ICD. A dual-sensitive methoxy-polyethylene glycol-SS-poly(L-γ-glutamylglutamine)-SS-IR780 (mPEG-SS-PGG-SS-IR780) polymer was synthesized by grafting IR780 with biodegradable di-carboxyl PGG as the backbone, and mPEG-SS-PGG-SS-IR780/paclitaxel micelles (mPEG-SS-PGG-SS-IR780/PTXL MCs) were synthesized by encapsulating PTXL in the hydrophobic core.

Results

In-vivo and -vitro results demonstrated that the three-mode combination micelles inhibited tumor growth and enhanced the therapeutic efficacy of immunotherapy. The dual stimuli-responsive mPEG-SS-PGG-SS-IR780/PTXL MCs were able to facilitate tumor cell endocytosis of nanoparticles. They were also capable of promoting micelles disintegration and accelerating PTXL release. The mPEG-SS-PGG-SS-IR780/PTXL MCs induced mitochondrial dysfunction by directly targeting the mitochondria, considering the thermo- and reactive oxygen species (ROS) sensitivity of the mitochondria. Furthermore, the mPEG-SS-PGG-SS-IR780/PTXL MCs could play the diagnostic and therapeutic roles via imaging capabilities.

Conclusion

In summary, this study formulated a high-efficiency nanoscale platform with great potential in combined therapy for tumors through ICD.

Controlled Release of Drug-Encapsulated Protein Films with Various Sodium Dodecyl Sulfate Concentrations

Protein-based drug carriers are ideal drug-delivery platforms because of their biocompatibility, biodegradability, and low toxicity. Many types and shapes of protein-based platforms, including nanoparticles, hydrogels, films, and minipellets, have been prepared to deliver drug molecules. In this study, protein films containing the desired amounts of doxorubicin (DOX) as cancer drugs were developed using a simple mixing method. The release ratio and rate of DOXs were dependent on the surfactant concentration. The drug release ratio was controlled within the range of 20-90% depending on the amount of the surfactant used. The protein film surface was analyzed using a microscope before and after drug release, and the relationship between the degree of film swelling and the drug release ratio was discussed. Moreover, the effects of cationic surfactants on the protein film were investigated. Non-toxic conditions of the protein films were confirmed in normal cells, while the toxicity of the drug-encapsulated protein film was confirmed in cancer cells. Remarkably, it was observed that the drug-encapsulated protein film could eliminate 10-70% of cancer cells, with the extent of efficacy varying based on the surfactant amount.

PEGylated and functionalized polylactide-based nanocapsules: An overview

Polymeric nanocapsules (NC) are versatile mixed vesicular nanocarriers, generally containing a lipid core with a polymeric wall. They have been first developed over four decades ago with outstanding applicability in the cosmetic and pharmaceutical fields. Biodegradable polyesters are frequently used in nanocapsule preparation and among them, polylactic acid (PLA) derivatives and copolymers, such as PLGA and amphiphilic block copolymers, are widely used and considered safe for different administration routes. PLA functionalization strategies have been developed to obtain more versatile polymers and to allow the conjugation with bioactive ligands for cell-targeted NC. This review intends to provide steps in the evolution of NC since its first report and the recent literature on PLA-based NC applications. PLA-based polymer synthesis and surface modifications are included, as well as the use of NC as a novel tool for combined treatment, diagnostics, and imaging in one delivery system. Furthermore, the use of NC to carry therapeutic and/or imaging agents for different diseases, mainly cancer, inflammation, and infections is presented and reviewed. Constraints that impair translation to the clinic are discussed to provide safe and reproducible PLA-based nanocapsules on the market. We reviewed the entire period in the literature where the term "nanocapsules" appears for the first time until the present day, selecting original scientific publications and the most relevant patent literature related to PLA-based NC. We presented to readers a historical overview of these Sui generis nanostructures.

Deformable and Disintegrable Multifunctional Integrated Polyprodrug Amphiphiles for Synergistic Phototherapy and Chemotherapy

Multimodal collaborative therapy has been recognized as one of the more effective means to eliminate tumors in the current biomedicine research field as compared with monotherapy. Among them, by taking advantage of its high-precision and controllability, phototherapy has become a mainstay of treatment. However, physical encapsulation of free photosensitive units within nanocarriers was one of the main implementations, which might inevitably result in the photosensitizer leakage and side effect. For this purpose, a kind of multifunctional integrated polyprodrug amphiphiles, P(PFO-IG-CPT)-PEG, were prepared by reversible addition-fragmentation chain transfer polymerization from polymerizable pentadecafluorooctan monomers, indocyanine green monomers, reduction-responsive camptothecin monomers, and acid-responsive PEG based methacrylate monomers (GMA(-OH/-PEG)). The resultant copolymers could self-assemble into spherical nanoparticles in water, performing size-deformability in acidic conditions and subsequent disintegration in reduction environment as demonstrated by in vitro experiments. Furthermore, an enhanced CPT release ratio and rate from nanoparticles could be achieved by a NIR irradiation due to the hyperthermia induced by the covalently linked IG moieties. Not only that, because of the sufficient O₂ content brought by PFO, the NIR light-triggered generation of ¹O₂ was also detected in cells. With the combination of CPT-guided chemotherapy as well as NIR light-guided photo-thermal and photodynamic therapies, fatal and irreversible damage to cancer cells was observed by cell experiments; the implanted tumor size in the mouse model was obviously shrunk upon receiving multimodal collaborative therapy. We speculate that such fabricated nanodiagnosis and treatment systems could meet the growing emergency for effective drug delivery, programmed and on-demand drug release, and multimodal integrated therapy.

Multifunctional Polymeric Micelles for Cancer Therapy

Polymeric micelles, nanosized assemblies of amphiphilic polymers with a core-shell architecture, have been used as carriers for various therapeutic compounds. They have gained attention due to specific properties such as their capacity to solubilize poorly water-soluble drugs, biocompatibility, and the ability to accumulate in tumor via enhanced permeability and retention (EPR). Moreover, additional functionality can be provided to the micelles by a further modification. For example, micelle surface modification with targeting ligands allows a specific targeting and enhanced tumor accumulation. The introduction of stimuli-sensitive groups leads to the drug's release in response to environment change. This review highlights the progress in the development of multifunctional polymeric micelles in the field of cancer therapy. This review will also cover some examples of multifunctional polymeric micelles that are applied for tumor imaging and theragnosis.