Sequential Drug Delivery in Targeted Cancer Therapy

Engineering of a double targeting nanoplatform to elevate ROS generation and DSF anticancer activity

Intracellular oxidative protection mechanisms and adverse systemic toxicity are major obstacles for the success of chemodynamic therapy (CDT)/chemotherapy (CT) synergistic therapy. To tackle the fundamental challenges of current CDT and circumvent the side effects of conventional CT, we developed a copper peroxide (CP) and disulfiram (DSF)-loaded 3-aminotriazole (3-AT) doped ZIF-8 (MAF) with partial sequence-specificity using hyaluronic acid (HA) and triphenylphosphine (TPP) in this study. Upon intravenous administration, CP@MAF-DSF@PEG-TPP@HA (CPMDTH) nanoparticles (NPs) were enriched in tumor tissues through HA-mediated endocytosis, followed by enhanced accumulation in mitochondria by the TPP target. The acidic tumor environment (TME) triggered the decomposition of MAF to release CP, DSF and 3-AT. Cu2+ and H2O2 hydrated from CP NPs produced ˙OH via a Fenton-like reaction. CAT activity inhibition and GSH consumption induced by 3-AT dramatically amplified mitochondrial oxidative stress, thereby promoting the overproduction of ˙OH. In addition, the accumulation of DSF and Cu2+ led to the formation of a cytotoxic bis(N,N-diethyldithiocarbamate) copper(II) complex (Cu(DTC)2) in situ, achieving efficient CT. CPMDTH NPs demonstrated significantly improved antitumor efficiency and excellent biosafety both in vitro and in vivo. This study offers a promising therapeutic strategy for CDT/CT synergistic oncotherapy.

Beyond the Maze: Recent Advancements in Molecular and Cellular Tethered Drug Delivery Systems

The relentless pursuit of precision medicine has catalyzed the development of molecular and cellular tethered drug delivery systems, a burgeoning field that stands to redefine the paradigms of therapeutic delivery. This review encapsulates the cutting-edge advancements within this domain, emphasizing the engineering of molecular tethers and cellular vectors designed to ferry therapeutics directly to their target sites with unparalleled specificity and efficiency. By exploiting the unique biochemical signatures of disease states, these systems promise a substantial reduction in off-target effects and an enhancement in drug bioavailability, thereby mitigating the systemic side effects that are often associated with conventional drug therapies. Through a synthesis of recent research findings, this review highlights the innovative approaches being explored in the design and application of these tethered systems, ranging from nanotechnology-based solutions to genetically engineered cellular carriers. The potential of these systems to provide targeted therapy for a wide array of diseases, including cancer, autoimmune disorders, and neurological conditions, is thoroughly examined. This abstract aims to provide a succinct overview of the current state and future prospects of molecular and cellular tethered drug delivery systems in advancing the frontiers of precision medicine.

Light-Responsive Layer-By-Layer Film Containing Gold Nanorods for Sequential Drug Release

Chemically and physically stable multidrug-loaded layer-by-layer (LbL) films are promising candidates for sequential and on-demand drug release at concentrations suitable for various applications. The synergistic effect of the sequential release of drugs may enhance their therapeutic efficacy in treating skin cancer and other complex medical conditions. In this study, we prepared LbL films by alternating the deposition of cationic linear polyethylenimine, camptothecin (CPT)-loaded gold nanorods (GNRs), anionic poly(styrenesulfonate), and doxorubicin (DOX) based on electrostatic interactions. The film exhibited loading of CPT and DOX, which could be tuned according to the requirements of the application by changing the parameters of the LbL process. Herein, CPT was encapsulated in GNRs and showed good stability and absorption in the near-infrared (NIR) range (650-900 nm). The prepared LbL film showed a pH-dependent DOX release. Subsequently, the functionalized GNRs showed excellent photothermal properties, which assisted the on-demand release of CPT upon NIR irradiation with further release of DOX. Our results suggest that the LbL approach for sequential drug release can be an effective drug delivery platform owing to its cytocompatibility, anticancer effects, and stimuli-responsive properties.

Injectable Thermoresponsive Microparticle/Hydrogel System with Superparamagnetic Nanoparticles for Drug Release and Magnetic Hyperthermia Applications

Cancer is a disease that continues to greatly impact our society. Developing new and more personalized treatment options is crucial to decreasing the cancer burden. In this study, we combined magnetic polysaccharide microparticles with a Pluronic thermoresponsive hydrogel to develop a multifunctional, injectable drug delivery system (DDS) for magnetic hyperthermia applications. Gellan gum and alginate microparticles were loaded with superparamagnetic iron oxide nanoparticles (SPIONs) with and without coating. The magnetic microparticles' registered temperature increases up to 4 °C upon the application of an alternating magnetic field. These magnetic microparticles were mixed with drug-loaded microparticles, and, subsequently, this mixture was embedded within a Pluronic thermoresponsive hydrogel that is capable of being in the gel state at 37 °C. The proposed DDS was capable of slowly releasing methylene blue, used as a model drug, for up to 9 days. The developed hydrogel/microparticle system had a smaller rate of drug release compared with microparticles alone. This system proved to be a potential thermoresponsive DDS suitable for magnetic hyperthermia applications, thus enabling a synergistic treatment for cancer.

AB Toxins as High-Affinity Ligands for Cell Targeting in Cancer Therapy

Conventional targeted therapies for the treatment of cancer have limitations, including the development of acquired resistance. However, novel alternatives have emerged in the form of targeted therapies based on AB toxins. These biotoxins are a diverse group of highly poisonous molecules that show a nanomolar affinity for their target cell receptors, making them an invaluable source of ligands for biomedical applications. Bacterial AB toxins, in particular, are modular proteins that can be genetically engineered to develop high-affinity therapeutic compounds. These toxins consist of two distinct domains: a catalytically active domain and an innocuous domain that acts as a ligand, directing the catalytic domain to the target cells. Interestingly, many tumor cells show receptors on the surface that are recognized by AB toxins, making these high-affinity proteins promising tools for developing new methods for targeting anticancer therapies. Here we describe the structure and mechanisms of action of Diphtheria (Dtx), Anthrax (Atx), Shiga (Stx), and Cholera (Ctx) toxins, and review the potential uses of AB toxins in cancer therapy. We also discuss the main advances in this field, some successful results, and, finally, the possible development of innovative and precise applications in oncology based on engineered recombinant AB toxins.

The Role of Molecular Imaging in Personalized Medicine

The concept of personalized medicine refers to the tailoring of medical treatment to each patient's unique characteristics. Scientific advancements have led to a better understanding of how a person's unique molecular and genetic profile makes them susceptible to certain diseases. It provides individualized medical treatments that will be safe and effective for each patient. Molecular imaging modalities play an essential role in this aspect. They are used widely in screening, detection and diagnosis, treatment, assessing disease heterogeneity and progression planning, molecular characteristics, and long-term follow-up. In contrast to conventional imaging approaches, molecular imaging techniques approach images as the knowledge that can be processed, allowing for the collection of relevant knowledge in addition to the evaluation of enormous patient groups. This review presents the fundamental role of molecular imaging modalities in personalized medicine.

Boosting Doxorubicin-Induced Mitochondria Apoptosis for the Monodrug-Mediated Combination of Chemotherapy and Chemodynamic Therapy

Doxorubicin (Dox)-mediated generation of reactive oxygen radicals (ROS) for mitochondrial apoptosis is identified as a new cytotoxic mechanism in addition to the well-established one via nuclear DNA replication interference. However, this mechanism contributes far less than the latter to Dox therapy. This newly identified pathway to make Dox therapy function like the combination of chemodynamic therapy (CDT) and chemotherapy-mediated by Dox alone would be amplified. One-pot nanoconstruction (HEBD) is fabricated based on the chemical reactions driven assemblies among epigallocatechin gallate (EGCG), buthionine sulfoximine (BSO) and formaldehyde in aqueous mediums followed by Dox adsorption. Acid tumor microenvironments allow the liberation of EGCG, BSO, and Dox due to the breakage of Schiff base bonds. EGCG component in HEBD is responsible for targeting mitochondria and disrupting mitochondrial electron transport chain (mETC) to compel electrons leakage in favor of their capture by Dox to produce more ROS. EGCG-induced mETC disruption results in mitochondrial respiration inhibition with alleviated hypoxia in tumor cells while BSO inhibits glutathione biosynthesis to protect ROS from redox depletion, further boosting Dox-induced CDT. This strategy of amplifying CDT pathway for the Dox-mediated combined therapy could largely improve antitumor effect, extend lifespan of tumor-bearing mice, reduce risks of cardiotoxicity and metastasis.

The Roles of MiRNAs (MicroRNAs) in Melanoma Immunotherapy

Melanoma is the most aggressive form of skin cancer, characterized by life-threatening and rapidly spreading progression. Traditional targeted therapy can alleviate tumors by inactivating hyperactive kinases such as BRAF or MEK but inevitably encounters drug resistance. The advent of immunotherapy has revolutionized melanoma treatment and significantly improved the prognosis of melanoma patients. MicroRNAs (miRNAs) are intricately involved in innate and adaptive immunity and are implicated in melanoma immunotherapy. This systematic review describes the roles of miRNAs in regulating the functions of immune cells in skin and melanoma, as well as the involvement of miRNAs in pharmacology including the effect, resistance and immune-related adverse events of checkpoint inhibitors such as PD-1 and CTLA-4 inhibitors, which are used for treating cutaneous, uveal and mucosal melanoma. The expressions and functions of miRNAs in immunotherapy employing tumor-infiltrating lymphocytes and Toll-like receptor 9 agonists are also discussed. The prospect of innovative therapeutic strategies such as the combined administration of miRNAs and immune checkpoint inhibitors and the nanotechnology-based delivery of miRNAs are also provided. A comprehensive understanding of the interplay between miRNAs and immunotherapy is crucial for the discovery of reliable biomarkers and for the development of novel miRNA-based therapeutics against melanoma.

The Anti-Cancer Effects of Mitochondrial-Targeted Triphenylphosphonium-Resveratrol Conjugate on Breast Cancer Cells

Breast cancer is the most commonly diagnosed cancer in women. Resveratrol, a naturally occurring phytochemical, shows great promise in developing novel anti-cancer therapies. This study hypothesized that the mitochondria-targeted delivery of resveratrol would increase its potency and induce mitochondria-mediated apoptosis. The targeted delivery of resveratrol was achieved by conjugating resveratrol to triphenylphosphonium (TPP). The anti-cancer effects of TPP-resveratrol were studied in the murine breast cancer 4T1 and the human breast cancer MDA-MB-231 cell lines. Flow cytometry was used to study apoptosis induction, cell cycle arrest, and mitochondrial membrane potential loss. The morphological changes in the mitochondria in MDA-MB-231 cells after TPP-resveratrol treatments were examined using transmission electron microscopy. Moreover, the changes in MDA-MB-231 cell metabolism after resveratrol and TPP-resveratrol treatments were studied using metabolomic analysis. We demonstrate that TPP-resveratrol significantly improved cytotoxicity in 4T1 cells and MDA-MB-231 cells by inducing apoptosis and mitochondrial membrane potential loss. Swollen and vacuolated mitochondria were observed after the TPP-resveratrol treatment. Meanwhile, TPP-resveratrol treatment down-regulated amino acid and energy metabolism and caused the dysfunction of purine and pyrimidine metabolism. Our results provide evidence supporting the targeted delivery of resveratrol to mitochondria and suggest that TPP-resveratrol may be an effective agent for breast cancer treatment.