Synthesis of Multifunctional Nanoparticles for the Combination of Photodynamic Therapy and Immunotherapy

Liposomal chlorin e6-mediated photodynamic therapy induces cell pyroptosis and promotes anti-tumor immune effects in breast cancer

Pyroptosis is a form of inflammatory cell death that has been demonstrated to trigger anti-tumor immune responses. Photodynamic therapy (PDT) is an innovative non-invasive treatment for tumors that effectively destroys tumor cells and boosts anti-tumor immune response. The ability of PDT to trigger pyroptosis and its mechanism of action are yet uncertain. In this study, we firstly verified that PDT effectively eliminates tumor cells. TEM and Western blot analysis demonstrated that tumor cells underwent pyroptosis following PDT therapy. Lipo-Ce6 mostly accumulates in the mitochondria of 4 T1 cells, and abundant ROS generated during PDT severely damage cell mitochondria, leading to the release of mitochondrial DNA, triggering the inflammasome caspase-1 signaling cascade, and ultimately causing cell pyroptosis, in addition NAC (a scavenger of ROS) and EB (a scavenger of mitochondrial DNA) can effectively prevent cell pyroptosis by PDT, which indicated the key role of ROS in PDT induced pyroptosis. Moreover, we also found PDT tiggered immunogenic cell death (ICD). Fourthermore, PDT can efficiently suppress tumor growth, trigger ICD and induce cell pyroptosis in mice. The introducing of immune checkpoint inhibitor BMS202 significantly boosts the tumor inhibition rate and promotes the infiltration of immune cells into the tumor. The body weight and HE. staining of normal organs primarily indicated the safety of this combined strategy. Our study demonstrated that PDT induced cell pyroptosis through mitochondrial oxidative damage and PDT induced pyroptosis effectively boost anti-cancer immunity, the combination of PDT and immune checkpoint inhibitor may be a promising clinical tumor treatment approaches.

Upconversion nanoparticle-based fluorescence resonance energy transfer sensing of programmed death ligand 1 using sandwich epitope-imprinted polymers

Programmed death ligand 1 (PD-L1) has been shown to suppress the anti-tumor immune response of some lung cancer patients, and thus PD-L1 expression may be a valuable predictor of the efficacy of anti-PD-1/PD-L1 monoclonal therapy in such patients. In this work, a sandwich approach to fluorescence resonance energy transfer (FRET) was used with green-emitting Yb3+/Ho3+-doped upconversion nanoparticles (UCNPs) and a rhodamine-conjugated conductive polymer as donor and acceptor, respectively. Yb3+/Ho3+-doped UCNPs were synthesized and then coated with poly(ethylene-co-vinyl alcohol), pEVAL, imprinted with PD-L1 peptide. Epitope-imprinted composite nanoparticles were characterized by dynamic light scattering, superconducting quantum interference magnetometry, and atomic force microscopy. Poly(triphenylamine rhodamine-3-acetic acid-co-3,4-ethoxylenedioxythiophene)s copolymers (p(TPAR-co-EDOT)) were imprinted with various epitopes of PD-L1 by in situ electrochemical polymerization. The epitope-imprinted polymer-coated electrodes were then characterized by scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. Finally, the sandwich sensing of various PD-L1 concentrations with peptide-imprinted p(TPAR-co-EDOT)-coated substrate and UCNP-containing magnetic peptide-imprinted pEVAL nanoparticles by FRET was conducted to measure the concentration of PD-L1 in A549 lung cancer cell lysate.

Molecularly Imprinted Carriers for Diagnostics and Therapy-A Critical Appraisal

Simultaneous diagnostics and targeted therapy provide a theranostic approach, an instrument of personalized medicine-one of the most-promising trends in current medicine. Except for the appropriate drug used during the treatment, a strong focus is put on the development of effective drug carriers. Among the various materials applied in the production of drug carriers, molecularly imprinted polymers (MIPs) are one of the candidates with great potential for use in theranostics. MIP properties such as chemical and thermal stability, together with capability to integrate with other materials are important in the case of diagnostics and therapy. Moreover, the MIP specificity, which is important for targeted drug delivery and bioimaging of particular cells, is a result of the preparation process, conducted in the presence of the template molecule, which often is the same as the target compound. This review focused on the application of MIPs in theranostics. As a an introduction, the current trends in theranostics are described prior to the characterization of the concept of molecular imprinting technology. Next, a detailed discussion of the construction strategies of MIPs for diagnostics and therapy according to targeting and theranostic approaches is provided. Finally, frontiers and future prospects are presented, stating the direction for further development of this class of materials.

Nanotherapeutic Intervention in Photodynamic Therapy for Cancer

The clinical need for photodynamic therapy (PDT) has been growing for several decades. Notably, PDT is often used in oncology to treat a variety of tumors since it is a low-risk therapy with excellent selectivity, does not conflict with other therapies, and may be repeated as necessary. The mechanism of action of PDT is the photoactivation of a particular photosensitizer (PS) in a tumor microenvironment in the presence of oxygen. During PDT, cancer cells produce singlet oxygen (¹O₂) and reactive oxygen species (ROS) upon activation of PSs by irradiation, which efficiently kills the tumor. However, PDT's effectiveness in curing a deep-seated malignancy is constrained by three key reasons: a tumor's inadequate PS accumulation in tumor tissues, a hypoxic core with low oxygen content in solid tumors, and limited depth of light penetration. PDTs are therefore restricted to the management of thin and superficial cancers. With the development of nanotechnology, PDT's ability to penetrate deep tumor tissues and exert desired therapeutic effects has become a reality. However, further advancement in this field of research is necessary to address the challenges with PDT and ameliorate the therapeutic outcome. This review presents an overview of PSs, the mechanism of loading of PSs, nanomedicine-based solutions for enhancing PDT, and their biological applications including chemodynamic therapy, chemo-photodynamic therapy, PDT-electroporation, photodynamic-photothermal (PDT-PTT) therapy, and PDT-immunotherapy. Furthermore, the review discusses the mechanism of ROS generation in PDT advantages and challenges of PSs in PDT.

Cellular Therapy Using Epitope-Imprinted Composite Nanoparticles to Remove α-Synuclein from an In Vitro Model

Several degenerative disorders of the central nervous system, including Parkinson’s disease (PD), are related to the pathological aggregation of proteins. Antibodies against toxic disease proteins, such as α-synuclein (SNCA), are therefore being developed as possible therapeutics. In this work, one peptide (YVGSKTKEGVVHGVA) from SNCA was used as the epitope to construct magnetic molecularly imprinted composite nanoparticles (MMIPs). These composite nanoparticles were characterized by dynamic light scattering (DLS), high-performance liquid chromatography (HPLC), isothermal titration calorimetry (ITC), Brunauer–Emmett–Teller (BET) analysis, and superconducting quantum interference device (SQUID) analysis. Finally, the viability of brain endothelial cells that were treated with MMIPs was measured, and the extraction of SNCA from CRISPR/dCas9a-activated HEK293T cells from the in vitro model system was demonstrated for the therapeutic application of MMIPs.

Progress of Nanomaterials in Photodynamic Therapy Against Tumor

Photodynamic therapy (PDT) is an advanced therapeutic strategy with light-triggered, minimally invasive, high spatiotemporal selective and low systemic toxicity properties, which has been widely used in the clinical treatment of many solid tumors in recent years. Any strategies that improve the three elements of PDT (light, oxygen, and photosensitizers) can improve the efficacy of PDT. However, traditional PDT is confronted some challenges of poor solubility of photosensitizers and tumor suppressive microenvironment. To overcome the related obstacles of PDT, various strategies have been investigated in terms of improving photosensitizers (PSs) delivery, penetration of excitation light sources, and hypoxic tumor microenvironment. In addition, compared with a single treatment mode, the synergistic treatment of multiple treatment modalities such as photothermal therapy, chemotherapy, and radiation therapy can improve the efficacy of PDT. This review summarizes recent advances in nanomaterials, including metal nanoparticles, liposomes, hydrogels and polymers, to enhance the efficiency of PDT against malignant tumor.

Embedded Upconversion Nanoparticles in Magnetic Molecularly Imprinted Polymers for Photodynamic Therapy of Hepatocellular Carcinoma

In this work, high-temperature pyrolysis was used to prepare both the core and shell of lantha-nide-doped UCNPs with lithium yttrium tetrafluoride (LiYF4) to enhance the green luminescence. Merocyanine 540 (MC540)-grafted magnetic nanoparticles were incorporated in the PD-L1 pep-tide-imprinted poly(ethylene-co-vinyl alcohol) particles, which were formed by precipitation in a non-solvent. UCNPs in the non-solvent bath were thus entrapped in the imprinted particles to generate composite nanoparticles for the targeting and photodynamic therapy of PD-L1 in tumor cells. Finally, the in vitro cytotoxicity of the nanoparticles in HepG2 human liver cancer cells was evaluated with the continuous administration of MC540/MNPs@MIPs/UCNPs under irradiation by an NIR laser. To understand the delivery of the UCNP-embedded molecularly imprinted pol-ymers, the intrinsic and extrinsic pathways were also investigated.