Macromolecular therapeutics in cancer treatment: the EPR effect and beyond

Facile lipid nanoparticle size engineering approach via controllable fusion induced by depletion forces

Lipid nanoparticles (LNPs) are among the most promising drug delivery carriers in research and development, with one major clinical application being messenger RNA (mRNA) vaccine. Current LNP production methods have the limit of generating low polydispersity index (PDI; PDI < 0.1) only for relatively small particles (<100 nm). It is known that larger LNPs have desirable properties, for example, particles with diameters in the 100 to 200 nm range have good immunogenicity. Yet, these larger particles' large PDI limits their clinical translation because of concerns about manufacturing reproducibility and possible side effects. We report here a facile approach to produce large and monodisperse (100-200 nm, PDI < 0.1) LNPs. The approach is based on adding 10 kDa polyethylene glycol (PEG) to a solution containing smaller LNPs. We show that PEG-induced depletion forces lead to the fusion of LNPs to form particles of approximately double the original size while keeping the same starting PDI. We discuss the fusion mechanism and show the parameters it depends on. In particular, we show that the fusion leads to a decrease in the fraction of empty LNPs. We show that the purification for PEG after fusion is simple and complete, thus, we believe that this is a method for the production of large LNP with low PDI that has a lot of potential to find industrial use.

Hybrid Systems of Gels and Nanoparticles for Cancer Therapy: Advances in Multifunctional Therapeutic Platforms

Cancer is a global health concern. Various therapeutic approaches, including chemotherapy, photodynamic therapy, and immunotherapy, have been developed for cancer treatment. Silica nanoparticles, quantum dots, and metal-organic framework (MOF)-based nanomedicines have gained interest in cancer therapy because of their selective accumulation in tumors via the enhanced permeability and retention (EPR) effect. However, bare nanoparticles face challenges including poor biocompatibility, low stability, limited drug-loading capacity, and rapid clearance by the reticuloendothelial system (RES). Gels with unique three-dimensional network structures formed through various interactions such as covalent and hydrogen bonds are emerging as promising materials for addressing these challenges. Gel hybridization enhances biocompatibility, facilitates controlled drug release, and confers cancer-targeting abilities to nanoparticles. This review discusses gel-nanoparticle hybrid systems for cancer treatment developed in the past five years and analyzes the roles of gels in these systems.

Anticancer Nanoparticle Carriers of the Proapoptotic Protein Cytochrome c

This review discusses the literature data on the synthesis, physicochemical properties, and cytotoxicity of composite nanoparticles bearing the mitochondrial protein cytochrome c (cytC), which can act as a proapoptotic mediator in addition to its main function as an electron carrier in the electron transport chain. The introduction of exogenous cytC via absorption of carrier particles, the phagocytosis of colloid particles of submicrometric size, or the receptor-mediated endocytosis of nanoparticles in cancer cells, initiates the process of apoptosis-a multistage cascade of biochemical reactions leading to complete destruction of the cells. CytC-carrier composite particles have the potential for use in the treatment of neoplasms with superficial localization: skin, mouth, stomach, colon, etc. This approach can solve the two main problems of anticancer therapy: selectivity and non-toxicity. Selectivity is based on the incapability of the normal cell to absorb (nano)particles, except for the cells of the immune system. The use of cytC as a protein that normally functions in mitochondria is harmless for the macroorganism. In this review, the factors limiting cytotoxicity and the ways to increase it are discussed from the point of view of the physicochemical properties of the cytC-carrier particles. The different techniques used for the preparation of cytC-bearing colloids and nanoparticles are discussed. Articles reporting the achievement of high cytotoxicity with each of the techniques are critically analyzed.

Ferritin versus Liposomes: A Comparative Analysis of Protein- and Lipid-Based Drug Delivery Systems

Drug delivery systems (DDSs) are crucial for the controlled release and targeted delivery of therapeutic agents, enhancing the stability and specificity of small molecules, nucleic acids, or peptides and addressing challenges such as drug instability and poor tissue targeting, particularly in oncology. Over the past few decades, liposomes have become one of the most widely used DDSs due to their unique physicochemical properties and biocompatibility. In the 1990s, liposomes were approved by the FDA as the first nanomedicine for disease treatment. Ferritin, a natural protein with a hollow nanocage structure, shares many similarities in architecture and functionality with liposomes. As an innovative DDS, ferritin offers distinct advantages including inherent tumor-targeting capabilities and exceptional biocompatibility. Liposomes and ferritin represent, respectively, established and emerging approaches in drug delivery, both excelling in key features like encapsulation efficiency and biocompatibility, which align with the standards for pharmaceutical carriers. While liposomal formulations have been clinically used, challenges such as precision targeting remain unresolved. In contrast, although ferritins hold considerable promise for drug delivery, they have not yet been implemented in clinical practice. In this review, we provide a comprehensive analysis of ferritins and liposomes as drug delivery vehicles, evaluating their drug-loading capacities, tumor-targeting capabilities, biocompatibility, and therapeutic potential. On the basis of a comparison of their intended applications and inherent limitations in the context of current treatment strategies, ferritin is expected to be an ideal delivery vehicle for tumor-targeted therapy and a strong candidate for clinical translation in the near future.

Dual Thermo- and pH-Responsive Polymer Nanoparticle Assemblies for Potential Stimuli-Controlled Drug Delivery

The development of stimuli-responsive drug delivery systems enables targeted delivery and environment-controlled drug release, thereby minimizing off-target effects and systemic toxicity. We prepared and studied tailor-made dual-responsive systems (thermo- and pH-) based on synthetic diblock copolymers consisting of a fully hydrophilic block of poly[N-(1,3-dihydroxypropyl)methacrylamide] (poly(DHPMA)) and a thermoresponsive block of poly[N-(2,2-dimethyl-1,3-dioxan-5-yl)methacrylamide] (poly(DHPMA-acetal)) as drug delivery and smart stimuli-responsive materials. The copolymers were designed for eventual medical application to be fully soluble in aqueous solutions at 25 °C. However, they form well-defined nanoparticles with hydrodynamic diameters of 50-800 nm when heated above the transition temperature of 27-31 °C. This temperature range is carefully tailored to align with the human body's physiological conditions. The formation of the nanoparticles and their subsequent decomposition was studied using dynamic light scattering (DLS), transmission electron microscopy (TEM), isothermal titration calorimetry (ITC), and nuclear magnetic resonance (NMR). 1H NMR studies confirmed that after approximately 20 h of incubation at pH 5, which closely mimics tumor microenvironment, approximately 40% of the acetal groups were hydrolyzed, and the thermoresponsive behavior of the copolymers was lost. This smart polymer response led to disintegration of the supramolecular structures, possibly releasing the therapeutic cargo. By tuning the transition temperature to the values relevant for medical applications, we ensure precise and effective drug release. In addition, our systems did not exhibit any cytotoxicity against any of the three cell lines. Our findings underscore the immense potential of these nanoparticles as eventual advanced drug delivery systems, especially for cancer therapy.

Advances in Drug Targeting, Drug Delivery, and Nanotechnology Applications: Therapeutic Significance in Cancer Treatment

In the 21st century, thanks to advances in biotechnology and developing pharmaceutical technology, significant progress is being made in effective drug design. Drug targeting aims to ensure that the drug acts only in the pathological area; it is defined as the ability to accumulate selectively and quantitatively in the target tissue or organ, regardless of the chemical structure of the active drug substance and the method of administration. With drug targeting, conventional, biotechnological and gene-derived drugs target the body's organs, tissues, and cells that can be selectively transported to specific regions. These systems serve as drug carriers and regulate the timing of release. Despite having many advantageous features, these systems have limitations in thoroughly treating complex diseases such as cancer. Therefore, combining these systems with nanoparticle technologies is imperative to treat cancer at both local and systemic levels effectively. The nanocarrier-based drug delivery method involves encapsulating target-specific drug molecules into polymeric or vesicular systems. Various drug delivery systems (DDS) were investigated and discussed in this review article. The first part discussed active and passive delivery systems, hydrogels, thermoplastics, microdevices and transdermal-based drug delivery systems. The second part discussed drug carrier systems in nanobiotechnology (carbon nanotubes, nanoparticles, coated, pegylated, solid lipid nanoparticles and smart polymeric nanogels). In the third part, drug targeting advantages were discussed, and finally, market research of commercial drugs used in cancer nanotechnological approaches was included.

Intraoperative imaging of residual ovarian cancer after neoadjuvant chemotherapy using indocyanine green

OBJECTIVES

Interval debulking surgery has similar outcomes and less morbidity compared with primary debulking in advanced ovarian cancer. However, there is controversy regarding the selection of chemotherapy-resistant clones. Complete resection is an essential prerequisite, and near-infrared surgery combined with various techniques for highlighting malignant foci strives to achieve actual complete resection. This study investigated the role of indocyanine green (ICG) in identifying additional residual malignant foci during interval debulking of apparently intact peritoneum not deemed clinically suspicious under white light inspection.

METHODS

Patients diagnosed with stage III or IV high-grade serous ovarian carcinoma, older than 18 years of age, with satisfactory hepatic and renal functions who underwent neoadjuvant chemotherapy according to the institutional protocol and were scheduled to undergo interval debulking surgery between 2020 and 2022 were deemed suitable for inclusion after agreeing to the study protocol and acknowledging no contraindications for the administration of the ICG product. After laparotomy and white light inspection, using bolus administration of ICG, additional suspect peritoneal samples in near infrared (defined by clinical hyper- or hypointensity areas compared with surrounding ICG fluorescence using the Zeiss Opmi Pentero 800 surgical microscope, that were not deemed clinically suspicious under white light) were excised. Descriptive statistics were inferred and the chi-square test was used for the comparison of excised areas. The Kaplan-Meier method was deployed for computing the overall survival and progression-free survival of the cohort. All statistical analyses were performed using IBM SPSS Statistics software.

RESULTS

Fifteen patients with a median age of 56 years were included. Most cases (n=10, 66.7%) were International Federation of Gynecology and Obstetrics (FIGO) stage III, and all patients received four to seven cycles of neoadjuvant platinum chemotherapy, with 40% of regimens using bevacizumab. The mean interval between neoadjuvant treatment and surgery was 39 (median 42, range 20-78) days. A total of 39 suspect additional peritoneal samples were analyzed, with 41% confirming malignant foci. The positive predictive value (PPV) for malignant foci was 30% in ICG hyperintense areas and 46% in ICG hypointense areas. Germline BRCA1/2 mutant patients and using neoadjuvant bevacizumab led to a higher PPV for ICG hypointense areas (60% and 72.7%, respectively). Overall, the number of additionally resected pathologically confirmed malignant lesions through ICG fluorescence increased by 25%.

CONCLUSIONS

The use of ICG was associated with an increase in the resection of samples with residual malignant foci. Overall, hypointense areas had a higher positive PPV for malignant foci in comparison with hyperintense ICG areas (46% vs 30%), which could be interpreted in the context of dynamic changes in the tumor microenvironment or enhanced permeability and retention effect following neoadjuvant chemotherapy.

A bleomycin-mimicking manganese-porphyrin-conjugated mitochondria-targeting peptoid for cancer therapy

Bleomycin (BLM) is a natural product with established anticancer activity, attributed to its ability to cleave intracellular DNA. BLM complexes with iron (BLM-Fe3+) exhibit peroxidase-like activity, generate reactive oxygen species (ROS), and cause DNA cleavage. Inspired by the mechanism of BLM, we synthesized a novel conjugate of manganese tetraphenylporphyrin (MnTPP) with a biomimetic peptoid (i.e., oligo-N-substituted glycines); this conjugate harnesses the oxidative capabilities of manganese porphyrins combined with the cell-penetrating ability of a previously reported mitochondria-targeting peptoid (MTP). UV-vis spectroscopy showed the formation of Mn(V)-oxo porphyrin, a potent oxidative species, in the presence of hydrogen peroxide, simulating metallobleomycin reactivity. Biological assays demonstrated that MnTPP-MTP significantly boosted ROS production and induced cytotoxicity toward cancer cells, while sparing normal fibroblasts. Tetramethylrhodamine ethyl ester (TMRE) assay revealed reversible, dose-dependent impairment of the mitochondrial membrane potential by MnTPP-MTP treatment. DNA cleavage assays showed that MnTPP-MTP, specifically in the presence of hydrogen peroxide, could elicit substantial DNA damage, in a similar way to BLM. In vivo studies using liposome-encapsulated MnTPP-MTP (lipo-peptoid) indicated superior tumor suppression, without systemic toxicity, when administered locally. Immunofluorescence staining for Ki67 and TUNEL confirmed reduced cell proliferation and increased apoptosis, respectively, validating the anticancer efficacy of lipo-peptoid. These results suggest that MnTPP-MTP, particularly in a liposomal formulation, is a promising new chemotherapeutic agent with robust oxidative mechanisms, poised for further development and application against diverse cancers.

Magnetic Resonance Imaging-Based Radiogenomic Analysis Reveals Genomic Determinants for Nanoparticle Delivery into Tumors

Even though the enhanced permeability and retention (EPR) effect is applicable for the passive targeting of solid tumors, many nanodrugs have failed to achieve meaningful clinical outcomes due to the heterogeneity of EPR effect. Therefore, understanding the mechanism of the EPR effect is crucial to overcome the obstacles nanomedicines face in clinical translation. The aim of this study was to establish a reliable method to increase awareness of the critical influencing factors of nanoparticle (NP) transport into tumors based on the EPR effect using a combined radiogenomics and clinical magnetic resonance imaging (MRI) technique and gene set pathway enrichment analysis. Employing poly(lactic-co-glycolic acid) (PLGA)-coated Fe3O4 NPs as the contrast agent, the monolayer and multilayer distribution of the NPs were observed and quantitatively analyzed by MRI, improving the accuracy of evaluating vascular permeability by MRI. By performing Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of genes and pathways, we identified a variety of genes affecting vascular permeability, such as Cldn1, Dlg2, Bves, Prkag3, Cldn10, and Cldn8, which are related to tight junctions and control the permeability of blood vessels in tumors. The method presented here provides an MRI-supported approach to increase the breadth of data collected from genetic screens, reveals genetic evidence of the presence of NPs in tumors and lays a foundation for clinical patient stratification and personalized treatment.

Synthesis and Characterization of Polyion Complex Micelles with Glycopolymer Shells for Drug Delivery Carriers

Double hydrophilic diblock copolymers (G20A100 and G100A98), composed of non-charged poly(glycosyloxyethyl methacrylate) (PGEMA, G) and cationic poly((3-acrylamidopropyl)trimethylammonium chloride), were synthesized via reversible addition-fragementation chain transfer (RAFT) radical polymerization. Likewise, diblock copolymers (G20S80 and G100S78), composed of PGEMA and anionic poly(2-acrylamido-2-methylpropanesulfonate) were synthesized via RAFT. The subscripts in these abbreviations indicate the degree of polymerization (DP) of each block. Polyion complex (PIC) aggregates (G20A100/G20S80 and G100A98/G100S78) were formed through electrostatic interactions by combining oppositely charged diblock copolymers with matched DPs for charge neutralization. The hydrodynamic radii of the G20A100/G20S80 and G100A98/G100S78 PIC aggregates were 77.4 and 26.2 nm, respectively, with zeta potentials close to 0 mV. The G20A100/G20S80 PIC micelles tend to form intermicellar aggregates, resulting in an increase in the particle size over time. In contrast, G100A98/G100S78 PIC micelles exhibited colloidal stability with a constant spherical core-shell shape, which was unaffected by time. The morphology and stability of the PIC aggregates depend upon the DP ratio of PGEMA and oppositely charged polyelectrolyte blocks. Both G20A100/G20S80 and G100A98/G100S78 PIC aggregates dissociated above 0.8 M NaCl due to the screening effect of NaCl.

Fluorescence-guided tumor visualization of colorectal cancer using tumor-initiating probe yellow in preclinical models

Fluorescence-guided surgery has emerged as an innovative technique with promising applications in the treatment of various tumors, including colon cancer. Tumor-initiating probe yellow (TiY) has been discovered for identifying tumorigenic cells by unbiased phenotypic screening with thousands of diversity-oriented fluorescence library (DOFL) compounds in a patient-derived lung cancer cell model. This study demonstrated the clinical feasibility of TiY for tumor-specific fluorescence imaging in the tissues of patients with colorectal cancer (CRC). To evaluate the efficacy of TiY in tumor imaging, surgical specimens were obtained, consisting of 36 tissues from 18 patients with CRC, for ex vivo molecular fluorescence imaging, histology, and immunohistochemistry. Orthotopic and chemically induced CRC mice models were administered TiY topically, and distinct tumor lesions were observed in 10 min by real-time fluorescence colonoscopy and ex vivo imaging. In a hepatic metastasis mouse model using splenic injection, TiY accumulation was detected in metastatic liver lesions through fluorescence imaging. Correlation analysis between TiY intensity and protein expression, assessed via immunohistochemistry and Western blotting, revealed a positive correlation between TiY and vimentin and Zeb1, which are known as epithelial-mesenchymal transition (EMT) markers of cancers. A comparative analysis of TiY with other FDA-approved fluorescence probes such as ICG revealed greater quantitative differences in TiY fluorescence intensity between tumor and normal tissues than those observed with ICG. Altogether, these results demonstrated that TiY has a strong potential for visualizing CRC by fluorescence imaging in various preclinical models, which can be further translated for clinical use such as fluorescence-guided surgery. Furthermore, our data indicate that TiY is preferentially uptaken by cells with EMT induction and progression, and overexpressing vimentin and Zeb1 in patients with CRC.

Hypocrellin: A Natural Photosensitizer and Nano-Formulation for Enhanced Molecular Targeting of PDT of Melanoma

Nano-formulation has generated attention in the battle against cancer, because of its great flexibility, reduced adverse side effects, and accuracy in delivering drugs to target tissues dependent on the size and surface characteristics of the disease. The field of photodynamic treatment has advanced significantly in the past years. Photodynamic techniques that use nano-formulations have surfaced to further the field of nanotechnology in medicine, especially in cancer treatment. The pharmaceutical industry is seeing a growing trend toward enhanced drug formulation using nano-formulations such as liposomes, polymeric nanoparticles, dendrimers, nano-emulsions, and micelles. Natural extracts have also shown adverse effects when employed as photosensitizers in cancer therapy because they are cytotoxic when activated by light. Still, natural photosensitizers are a big part of cancer treatment. However, some shortcomings can be minimized by combining nano-formulations with these natural photosensitizers. The synergistic improvement in medication delivery that maintains or increases the mechanism of cell death in malignant cells has also been demonstrated by the combination of photodynamic therapy with nano-formulations and natural photosensitizers. Lastly, this review assesses the feasibility and potential of a photodynamic therapy system based on nano-formulations and natural photosensitizers in clinical treatment applications and briefly discusses the removal of toxic compounds associated with nano-formulations within cells.

Physiological and tumor-associated angiogenesis: Key factors and therapy targeting VEGF/VEGFR pathway

Cancer remains one of the leading causes of death worldwide and poses a significant challenge to effective treatment due to its complexity. Angiogenesis, the formation of new blood vessels, is one of the cancer hallmarks and is a critical process in tumor growth and metastasis. The pivotal role of angiogenesis in cancer development has made antiangiogenic treatment a promising strategy for cancer therapy. To develop an effective therapy, it is essential to understand the basics of the physiological and tumor angiogenesis process. This review presents the primary factors related to physiological and tumor angiogenesis and the mechanisms of angiogenesis in tumors. We summarize potential molecular targets for cancer treatment by focusing on the vasculature, with the VEGF/VEGFR pathway being one of the most important and well-studied. Additionally, we present the advantages and limitations of currently used clinical protocols for cancer treatment targeting the VEGF/VEGFR pathway.

What is the Reason That the Pharmacological Future of Chemotherapeutics in the Treatment of Lung Cancer Could Be Most Closely Related to Nanostructures? Platinum Drugs in Therapy of Non-Small and Small Cell Lung Cancer and Their Unexpected, Possible Interactions. The Review

Over the course of several decades, anticancer treatment with chemotherapy drugs for lung cancer has not changed significantly. Unfortunately, this treatment prolongs the patient's life only by a few months, causing many side effects in the human body. It has also been proven that drugs such as Cisplatin, Carboplatin, Oxaliplatin and others can react with other substances containing an aromatic ring in which the nitrogen atom has a free electron group in its structure. Thus, such structures may have a competitive effect on the nucleobases of DNA. Therefore, scientists are looking not only for new drugs, but also for new alternative ways of delivering the drug to the cancer site. Nanotechnology seems to be a great hope in this matter. Creating a new nanomedicine would reduce the dose of the drug to an absolute minimum, and thus limit the toxic effect of the drug; it would allow for the exclusion of interactions with competitive compounds with a structure similar to nucleobases; it would also permit using the so-called targeted treatment and bypassing healthy cells; it would allow for the introduction of other treatment options, such as radiotherapy directly to the cancer site; and it would provide diagnostic possibilities. This article is a review that aims to systematize the knowledge regarding the anticancer treatment of lung cancer, but not only. It shows the clear possibility of interactions of chemotherapeutics with compounds competitive to the nitrogenous bases of DNA. It also shows the possibilities of using nanostructures as potential Platinum drug carriers, and proves that nanomedicine can easily become a new medicinal product in personalized medicine.

Advancing Ovarian Cancer Therapeutics: The Role of Targeted Drug Delivery Systems

Ovarian cancer (OC) is the most lethal reproductive system cancer and a leading cause of cancer-related death. The high mortality rate and poor prognosis of OC are primarily due to its tendency for extensive abdominal metastasis, late diagnosis in advanced stages, an immunosuppressive tumor microenvironment, significant adverse reactions to first-line chemotherapy, and the development of chemoresistance. Current adjuvant chemotherapies face challenges such as poor targeting, low efficacy, and significant side effects. Targeted drug delivery systems (TDDSs) are designed to deliver drugs precisely to the tumor site to enhance efficacy and minimize side effects. This review highlights recent advancements in the use of TDDSs for OC therapies, including drug conjugate delivery systems, nanoparticle drug delivery systems, and hydrogel drug delivery systems. The focus is on employing TDDS to conduct direct, effective, and safer interventions in OC through methods such as targeted tumor recognition and controlled drug release, either independently or in combination. This review also discusses the prospects and challenges for further development of TDDSs. Undoubtedly, the use of TDDSs shows promise in the battle against OCs.

Stimuli-Responsive Polymers at the Interface with Biology

There has been growing interest in polymeric systems that break down or undergo property changes in response to stimuli. Such polymers can play important roles in biological systems, where they can be used to control the release of therapeutics, modulate imaging signals, actuate movement, or direct the growth of cells. In this Perspective, after discussing the most important stimuli relevant to biological applications, we will present a selection of recent exciting developments. The growing importance of stimuli-responsive polysaccharides will be discussed, followed by a variety of stimuli-responsive polymeric systems for the delivery of small molecule drugs and nucleic acids. Switchable polymers for the emerging area of therapeutic response measurement in theranostics will be described. Then, the diverse functions that can be achieved using hydrogels cross-linked covalently, as well as by various dynamic approaches will be presented. Finally, we will discuss some of the challenges and future perspectives for the field.

Strategies for the development of metalloimmunotherapies

Metal ions play crucial roles in the regulation of immune pathways. In fact, metallodrugs have a long record of accomplishment as effective treatments for a wide range of diseases. Here we argue that the modulation of interactions of metal ions with molecules and cells involved in the immune system forms the basis of a new class of immunotherapies. By examining how metal ions modulate the innate and adaptive immune systems, as well as host-microbiota interactions, we discuss strategies for the development of such metalloimmunotherapies for the treatment of cancer and other immune-related diseases.

Detection of Hepatocellular Carcinoma in an Orthotopic Patient-Derived Xenograft with an Epithelial Cell Adhesion Molecule-Specific Peptide

Hepatocellular carcinoma (HCC) has emerged as a major contributor to the worldwide cancer burden. Improved methods are needed for early cancer detection and image-guided surgery. Peptides have small dimensions that can overcome delivery challenges to achieve high tumor concentrations and deep penetration. We used phage display methods to biopan against the extra-cellular domain of the purified EpCAM protein, and used IRDye800 as a near-infrared (NIR) fluorophore. The 12-mer sequence HPDMFTRTHSHN was identified, and specific binding to EpCAM was validated with HCC cells in vitro. A binding affinity of kd = 67 nM and onset of k = 0.136 min-1 (7.35 min) were determined. Serum stability was measured with a half-life of T1/2 = 2.6 h. NIR fluorescence images showed peak uptake in vivo by human HCC patient-derived xenograft (PDX) tumors at 1.5 h post-injection. Also, the peptide was able to bind to foci of local and distant metastases in liver and lung. Peptide biodistribution showed high uptake in tumor versus other organs. No signs of acute toxicity were detected during animal necropsy. Immunofluorescence staining of human liver showed specific binding to HCC compared with cirrhosis, adenoma, and normal specimens.

Stimulating macropinocytosis of peptide-drug conjugates through DNA-dependent protein kinase inhibition for treating KRAS-mutant cancer

KRAS-mutant cancers, due to their protein targeting complexity, present significant therapeutic hurdles. The identification of the macropinocytic phenotype in these cancers has emerged as a promising alternative therapeutic target. Our study introduces MPD1, an macropinocytosis-targeting peptide-drug conjugates (PDC), which is developed to treat KRAS mutant cancers. This PDC is specifically designed to trigger a positive feedback loop through its caspase-3 cleavable characteristic. However, we observe that this loop is hindered by DNA-PK mediated DNA damage repair processes in cancer cells. To counter this impediment, we employ AZD7648, a DNA-PK inhibitor. Interestingly, the combined treatment of MPD1 and AZD7648 resulted in a 100% complete response rate in KRAS-mutant xenograft model. We focus on the synergic mechanism of it. We discover that AZD7648 specifically enhances macropinocytosis in KRAS-mutant cancer cells. Further analysis uncovers a significant correlation between the increase in macropinocytosis and PI3K signaling, driven by AMPK pathways. Also, AZD7648 reinforces the positive feedback loop, leading to escalated apoptosis and enhanced payload accumulation within tumors. AZD7648 possesses broad applications in augmenting nano-sized drug delivery and preventing DNA repair resistance. The promising efficacy and evident synergy underscore the potential of combining MPD1 with AZD7648 as a strategy for treating KRAS-mutant cancers.

Polymer-Tethered Quenched Fluorescent Probes for Enhanced Imaging of Tumor-Associated Proteases

Fluorescence-based contrast agents enable real-time detection of solid tumors and their neovasculature, making them ideal for use in image-guided surgery. Several agents have entered late-stage clinical trials or secured FDA approval, suggesting they are likely to become the standard of care in cancer surgeries. One of the key parameters to optimize in contrast agents is molecular size, which dictates much of the pharmacokinetic and pharmacodynamic properties of the agent. Here, we describe the development of a class of protease-activated quenched fluorescent probes in which a N-(2-hydroxypropyl)methacrylamide copolymer is used as the primary scaffold. This copolymer core provides a high degree of probe modularity to generate structures that cannot be achieved with small molecules and peptide probes. We used a previously validated cathepsin substrate and evaluated the effects of length and type of linker, as well as the positioning of the fluorophore/quencher pair on the polymer core. We found that the polymeric probes could be optimized to achieve increased overall signal and tumor-to-background ratios compared to the reference small molecule probe. Our results also revealed multiple structure-activity relationship trends that can be used to design and optimize future optical imaging probes. Furthermore, they confirm that a hydrophilic polymer is an ideal scaffold for use in optical imaging contrast probes, allowing a highly modular design that enables efficient optimization to maximize probe accumulation and overall biodistribution properties.

Construction of Smart DNA-Based Drug Delivery Systems for Cancer Therapy

Due to the disadvantages of poor targeting, slow action, and low effectiveness of current commonly used cancer treatments, including surgery, chemotherapy, and radiotherapy, researchers have turned to DNA as a biomaterial for constructing drug delivery nanocarriers. DNA is favored for its biocompatibility and programmability. In order to overcome the limitations associated with traditional drug delivery systems (DDSs), researchers have developed smart-responsive DNA DDSs that can control drug release in response to specific physical or chemical stimuli at targeted sites. In this review, a summary of multiple targeted ligand structures is provided, various shapes of stable DNA nanomaterials, and different stimuli-responsive drug release strategies in DNA DDSs. Specifically, targeted cell recognition, in vivo stable transport, and controlled drug release of smart DDSs are focused. Finally, the further development prospects and challenges of clinical application of DNA nanomaterials in the field of smart drug delivery are discussed. The objective of this review is to enhance researchers' comprehension regarding the potential application of DNA nanomaterials in precision drug delivery, with the aim of expediting the clinical implementation of intelligent DDSs.

Evaluating a targeted Palbociclib-Trastuzumab loaded smart niosome platform for treating HER2 positive breast cancer cells

In this study, we present a targeted and pH-sensitive niosomal (pHSN) formulation, incorporating quantum dot (QD)-labeled Trastuzumab (Trz) molecules for the specific delivery of Palbociclib (Pal) to cells overexpressing human epidermal growth factor receptor 2 (HER2). FTIR analyses confirmed the successful preparation of the pHSNs and their bioconjugation. The labeled Trz-conjugated Pal-pHSNs (Trz-Pal-pHSNs) exhibited a size of approximately 170 nm, displaying a spherical shape with a neutral surface charge of -1.2 mV. Pal encapsulation reached ∼86%, and the release pattern followed a two-phase pH-dependent mechanism. MTT assessments demonstrated enhanced apoptosis induction, particularly in HER2-positive cells, by Trz-Pal-pHSNs. Fluorescence imaging further validated the internalization of particles into cells. In conclusion, Trz-Pal-pHSNs emerge as a promising platform for personalized medicine in the treatment of HER2-positive breast cancer.

Polymer-tethered quenched fluorescent probes for enhanced imaging of tumor associated proteases

Fluorescence-based contrast agents enable real-time detection of solid tumors and their neovasculature, making them ideal for use in image-guided surgery. Several agents have entered late-stage clinical trials or secured FDA approval, suggesting they are likely to become standard of care in cancer surgeries. One of the key parameters to optimize in contrast agent is molecular size, which dictates much of the pharmacokinetic and pharmacodynamic properties of the agent. Here, we describe the development of a class of protease-activated quenched fluorescent probes in which a N-(2-hydroxypropyl)methacrylamide copolymer is used as the primary scaffold. This copolymer core provides a high degree of probe modularity to generate structures that cannot be achieved with small molecules and peptide probes. We used a previously validated cathepsin substrate and evaluated the effects of length and type of linker as well as positioning of the fluorophore/quencher pair on the polymer core. We found that the polymeric probes could be optimized to achieve increased over-all signal and tumor-to-background ratios compared to the reference small molecule probe. Our results also revealed multiple structure-activity relationship trends that can be used to design and optimize future optical imaging probes. Furthermore, they confirm that a hydrophilic polymer is an ideal scaffold for use in optical imaging contrast probes, allowing a highly modular design that enables efficient optimization to maximize probe accumulation and overall biodistribution properties.

A stable, highly concentrated fluorous nanoemulsion formulation for in vivo cancer imaging via 19F-MRI

Magnetic resonance imaging (MRI) is a routine diagnostic modality in oncology that produces excellent imaging resolution and tumor contrast without the use of ionizing radiation. However, improved contrast agents are still needed to further increase detection sensitivity and avoid toxicity/allergic reactions associated with paramagnetic metal contrast agents, which may be seen in a small percentage of the human population. Fluorine-19 (19F)-MRI is at the forefront of the developing MRI methodologies due to near-zero background signal, high natural abundance of 100%, and unambiguous signal specificity. In this study, we have developed a colloidal nanoemulsion (NE) formulation that can encapsulate high volumes of the fluorous MRI tracer, perfluoro-[15-crown-5]-ether (PFCE) (35% v/v). These nanoparticles exhibit long-term (at least 100 days) stability and high PFCE loading capacity in formulation with our semifluorinated triblock copolymer, M2F8H18. With sizes of approximately 200 nm, these NEs enable in vivo delivery and passive targeting to tumors. Our diagnostic formulation, M2F8H18/PFCE NE, yielded in vivo 19F-MR images with a high signal-to-noise ratio up to 100 in a tumor-bearing mouse model at clinically relevant scan times. M2F8H18/PFCE NE circulated stably in the vasculature, accumulated in high concentration of an estimated 4-9 × 1017 19F spins/voxel at the tumor site, and cleared from most organs over the span of 2 weeks. Uptake by the mononuclear phagocyte system to the liver and spleen was also observed, most likely due to particle size. These promising results suggest that M2F8H18/PFCE NE is a favorable 19F-MR diagnostic tracer for further development in oncological studies and potential clinical translation.

Weakly acidic pH-responsive liposomal content release induced by histidine-modified agents

Internal stimuli-responsive controlled release from liposomal vesicles is an innovative approach for site-specific delivery of therapeutic drugs. In this study, to enhance the endosomal pH control of drug release from liposomes, a series of histidine-modified pH-sensitive Cn-His (n = 8, 12, 18) agents were designed and utilized as triggers for liposomal content release. The pH-dependent properties of Cn-His-incorporated liposomes were characterized using dynamic light scattering, ζ-potential, and fluorescence spectroscopy. The liposomes maintained a relatively uniform size across all pH conditions. However, the ζ-potential exhibited positive values at endosomal acidic pH levels and neutral or negative values at physiological pH levels. Furthermore, acidic pH-dependent release of both polar content (carboxyfluorescein) and nonpolar content (Nile red) was observed from the Cn-His-incorporated liposomes. Notably, with C12-His as the pH sensitizer, the pH dependence of liposomal content release was significantly evident. This work establishes endosomal pH-controllable liposome platforms, laying the groundwork for developing clinically applicable triggered release formulations.

Chemical modification of bradykinin-polymer conjugates for optimum delivery of nanomedicines to tumors

We recently prepared pH-responsive HPMA copolymer conjugates of bradykinin (P-BK), which release BK in response to the acidic tumor microenvironment, and found that administration of P-BK increased the tumor accumulation and therapeutic efficacy of nanomedicine. Because the release of BK from P-BK determines its onset of action, P-BKs with different release rates were prepared, and their properties were evaluated. The release kinetics were significantly altered by substitution proximal to hydrazone bond, release constant of methyl-substituted P-BK (P-MeBK) was approximately 4- and 80-fold higher than that of cyclopropyl-substituted P-BK (P-CPBK) and phenyl-substituted P-BK (P-PhBK). None of the P-BKs were active, but the release of BK restored their BK-like activity. Pre-administration of the P-BKs increased the tumor accumulation of nanomedicine in C26 tumor-bearing mice by 2- and 1.4-fold for P-MeBK and P-PhBK at 3 and 6 h. Altogether, this study provides insights into the design of pH-responsive nanodrugs with the desired release properties to target acidic lesions such as cancer and inflammation.

MicroRNA-targeting nanomedicines for the treatment of intervertebral disc degeneration

Low back pain stands as a pervasive global health concern, afflicting almost 80% of adults at some point in their lives with nearly 40% attributable to intervertebral disc degeneration (IVDD). As only symptomatic relief can be offered to patients there is a dire need for innovative treatments.Given the accumulating evidence that multiple microRNAs (miRs) are dysregulated during IVDD, they could have a huge potential against this debilitating condition. The way miRs can profoundly modulate signaling pathways and influence several cellular processes at once is particularly exciting to tackle this multifaceted disorder. However, miR delivery encounters extracellular and intracellular biological barriers. A promising technology to address this challenge is the vectorization of miRs within nanoparticles, providing both protection and enhancing their uptake within the scarce target cells of the degenerated IVD. This comprehensive review presents the diverse spectrum of miRs' connection with IVDD and demonstrates their therapeutic potential when vectorized in nanomedicines.

A Review on Emerging Techniques for Diagnosis of Colorectal Cancer

Common detection methods in practice for diagnosing colorectal cancer (CRC) are painful and invasive leading to less participation of individuals for CRC diagnosis. Whereas, improved or enhanced imaging systems and other minimally invasive techniques with shorter detection times deliver greater detail and less discomfort in individuals. Thus, this review is a summary of the diagnostic tests, ranging from the simple potential use in developing a flexible CRC treatment to the patient's potential benefits in receiving less invasive procedures and the advanced treatments that might provide a better assessment for the diagnosis of CRC and reduce the mortality related to CRC.

Key processes in tumor metastasis and therapeutic strategies with nanocarriers: a review

Cancer metastasis is the leading cause of cancer-related death. Metastasis occurs at all stages of tumor development, with unexplored changes occurring at the primary site and distant colonization sites. The growing understanding of the metastatic process of tumor cells has contributed to the emergence of better treatment options and strategies. This review summarizes a range of features related to tumor cell metastasis and nanobased drug delivery systems for inhibiting tumor metastasis. The mechanisms of tumor metastasis in the ideal order of metastatic progression were summarized. We focus on the prominent role of nanocarriers in the treatment of tumor metastasis, summarizing the latest applications of nanocarriers in combination with drugs to target important components and processes of tumor metastasis and providing ideas for more effective nanodrug delivery systems.

Stepwise optimization of tumor-targeted dual-action platinum(iv)-gemcitabine prodrugs

While platinum-based chemotherapeutic agents have established themselves as indispensable components of anticancer therapy, they are accompanied by a variety of side effects and the rapid occurrence of drug resistance. A promising strategy to address these challenges is the use of platinum(iv) prodrugs, which remain inert until they reach the tumor tissue, thereby mitigating detrimental effects on healthy cells. Typically, platinum drugs are part of combination therapy settings. Consequently, a very elegant strategy is the development of platinum(iv) prodrugs bearing a second, clinically relevant therapeutic in axial position. In the present study, we focused on gemcitabine as an approved antimetabolite, which is highly synergistic with platinum drugs. In addition, to increase plasma half-life and facilitate tumor-specific accumulation, an albumin-binding maleimide moiety was attached. Our investigations revealed that maleimide-cisplatin(iv)-gemcitabine complexes cannot carry sufficient amounts of gemcitabine to induce a significant effect in vivo. Consequently, we designed a carboplatin(iv) analog, that can be applied at much higher doses. Remarkably, this novel analog demonstrated impressive in vivo results, characterized by significant improvements in overall survival. Notably, these encouraging results could also be transferred to an in vivo xenograft model with acquired gemcitabine resistance, indicating the high potential of this approach.

Microfluidics-mediated Liposomal Nanoparticles for Cancer Therapy: Recent Developments on Advanced Devices and Technologies

Liposomes, spherical particles with phospholipid double layers, have been extensively studied over the years as a means of drug administration. Conventional manufacturing techniques like thin-film hydration and extrusion have limitations in controlling liposome size and distribution. Microfluidics enables superior tuning of parameters during the self-assembly of liposomes, producing uniform populations. This review summarizes microfluidic methods for engineering liposomes, including hydrodynamic flow focusing, jetting, micro mixing, and double emulsions. The precise control over size and lamellarity afforded by microfluidics has advantages for cancer therapy. Liposomes created through microfluidics and designed to encapsulate chemotherapy drugs have exhibited several advantageous properties in cancer treatment. They showcase enhanced permeability and retention effects, allowing them to accumulate specifically in tumor tissues passively. This passive targeting of tumors results in improved drug delivery and efficacy while reducing systemic toxicity. Promising results have been observed in pancreatic, lung, breast, and ovarian cancer models, making them a potential breakthrough in cancer therapy. Surface-modified liposomes, like antibodies or carbohydrates, also achieve active targeting. Overall, microfluidic fabrication improves reproducibility and scalability compared to traditional methods while maintaining drug loading and biological efficacy. Microfluidics-engineered liposomal formulations hold significant potential to overcome challenges in nanomedicine-based cancer treatment.

Exploring the Potential of Nanogels: From Drug Carriers to Radiopharmaceutical Agents

Nanogels open up access to a wide range of applications and offer among others hopeful approaches for use in the field of biomedicine. This review provides a brief overview of current developments of nanogels in general, particularly in the fields of drug delivery, therapeutic applications, tissue engineering, and sensor systems. Specifically, cyclodextrin (CD)-based nanogels are important because they have exceptional complexation properties and are highly biocompatible. Nanogels as a whole and CD-based nanogels in particular can be customized in a wide range of sizes and equipped with a desired surface charge as well as containing additional molecules inside and outside, such as dyes, solubility-mediating groups or even biological vector molecules for pharmaceutical targeting. Currently, biological investigations are mainly carried out in vitro, but more and more in vivo applications are gaining importance. Modern molecular imaging methods are increasingly being used for the latter. Due to an extremely high sensitivity and the possibility of obtaining quantitative data on pharmacokinetic and pharmacodynamic properties, nuclear methods such as single photon emission computed tomography (SPECT) and positron emission tomography (PET) using radiolabeled compounds are particularly suitable here. The use of radiolabeled nanogels for imaging, but also for therapy, is being discussed.

Direct immunoactivation by chemotherapeutic drugs in cancer treatment

The immune system plays a crucial role in recognizing and eliminating pathogenic substances and malignant cells in the body. For cancer treatment, immunotherapy is becoming the standard treatment for many types of cancer and is often combined with chemotherapy. Although chemotherapeutic agents are often reported to have adverse effects, including immunosuppression, they can also play a positive role in immunotherapy by directly stimulating the immune system. This has been demonstrated in preclinical and clinical studies in the past decades. Chemotherapeutics can activate immune cells through different immune receptors and signaling pathways depending on their chemical structure and formulation. In this review, we summarize and discuss the direct immunoactivation effects of chemotherapeutics and possible mechanisms behind these effects. Finally, we prospect chemo-immunotherapeutic combinations for the more effective and safer treatment of cancer.

Optimization of PLGA-DSPE hybrid nano-micelles with enhanced hydrophobic capacity for curcumin delivery

Poly (D, L Lactic-co-Glycolic acid) (PLGA) is an FDA-approved polymer. It is distinguished from other biocompatible polymers by its feasibility of production and safety for intravenous cancer tumor targeting. Curcumin (CUR) is a natural molecule with versatile bioactivities including inhibiting the nuclear Factor kappa B (Nf-kB) levels in cancer cells, increased by chemotherapy agents. Our group previously reported a successful decrease in the p65 (RelA) subunit of Nf-kB using 125 µg/ml CUR loaded into PLGA nano-micelles. However, this amount was insufficient to reduce all Nf-kB subunits. This study aimed to increase the hydrophobic capacity of PLGA toward CUR using 1,2-Distearoyl-sn-glycerol-3-phosphoethanolamine (DSPE), an FDA-approved phospholipid. PLGA-DSPE hybrid nano-micelles (HNM) were prepared using two different methods, oil-in-water (OiWa) and film preparation-rehydration (FiRe). The encapsulated CUR was successfully increased to 250 µg/ml using the FiRe method. Physicochemical characterization of CUR-loaded HNM was performed using DLS FT-IR, DSC, and HPLC. In HNM with a size of 156.6 nm, DSPE, incorporated with all functional groups of PLGA, and CUR was trapped in the core of this structure. The release profile of CUR was suitable for targeted cancer therapy and the Encapsulation Efficacy was 92%.

Biodegradable polyester-based nano drug delivery system in cancer chemotherapy: a review of recent progress (2021-2023)

Cancer presents a formidable threat to human health, with the majority of cases currently lacking a complete cure. Frequently, chemotherapy drugs are required to impede its progression. However, these drugs frequently suffer from drawbacks such as poor selectivity, limited water solubility, low bioavailability, and a propensity for causing organ toxicity. Consequently, a concerted effort has been made to seek improved drug delivery systems. Nano-drug delivery systems based on biodegradable polyesters have emerged as a subject of widespread interest in this pursuit. Extensive research has demonstrated their potential for offering high bioavailability, effective encapsulation, controlled release, and minimal toxicity. Notably, poly (ε-caprolactone) (PCL), poly (lactic-co-glycolic acid) (PLGA), and polylactic acid (PLA) have gained prominence as the most widely utilized options as carriers of the nano drug delivery system. This paper comprehensively reviews recent research on these materials as nano-carriers for delivering chemotherapeutic drugs, summarizing their latest advancements, acknowledging their limitations, and forecasting future research directions.

In vivo MR imaging for tumor-associated initial neovascularization by supramolecular contrast agents

Microvascular imaging is required to understand tumor angiogenesis development; however, an appropriate whole-body imaging method has not yet been established. Here, we successfully developed a supramolecular magnetic resonance (MR) contrast agent for long-term whole-tissue observation in a single individual. Fluorescein- and Gd-chelate-conjugated polyethylene glycols (PEGs) were synthesized, and their structures were optimized. Spectroscopic and pharmacokinetic analyses suggested that the fluorescein-conjugated linear and 8-arm PEGs with a molecular weight of approximately 10 kDa were suitable to form a supramolecular structure to visualize the microvessel structure and blood circulation. Microvascular formation was evaluated in a glioma cell transplantation model, and neovascularization around the glioma tissue at 5 days was observed, with the contrast agent leaking out into the cancer tissue. In contrast, after 12 days, microvessel structures were formed inside the glioma tissue, but the agents did not leak out. These imaging data for the first time proved that the microvessels formed inside cancer tissues at the early stage are very leaky, but that they form continuous microvessels after 12 days.

Meeting Contemporary Challenges: Development of Nanomaterials for Veterinary Medicine

In recent decades, nanotechnology has been rapidly advancing in various fields of human activity, including veterinary medicine. The review presents up-to-date information on recent advancements in nanotechnology in the field and an overview of the types of nanoparticles used in veterinary medicine and animal husbandry, their characteristics, and their areas of application. Currently, a wide range of nanomaterials has been implemented into veterinary practice, including pharmaceuticals, diagnostic devices, feed additives, and vaccines. The application of nanoformulations gave rise to innovative strategies in the treatment of animal diseases. For example, antibiotics delivered on nanoplatforms demonstrated higher efficacy and lower toxicity and dosage requirements when compared to conventional pharmaceuticals, providing a possibility to solve antibiotic resistance issues. Nanoparticle-based drugs showed promising results in the treatment of animal parasitoses and neoplastic diseases. However, the latter area is currently more developed in human medicine. Owing to the size compatibility, nanomaterials have been applied as gene delivery vectors in veterinary gene therapy. Veterinary medicine is at the forefront of the development of innovative nanovaccines inducing both humoral and cellular immune responses. The paper provides a brief overview of current topics in nanomaterial safety, potential risks associated with the use of nanomaterials, and relevant regulatory aspects.

Tuning the Cross-Linking Density and Cross-Linker in Core Cross-Linked Polymeric Micelles and Its Effects on the Particle Stability in Human Blood Plasma and Mice

Core cross-linked polymeric micelles (CCPMs) are designed to improve the therapeutic profile of hydrophobic drugs, reduce or completely avoid protein corona formation, and offer prolonged circulation times, a prerequisite for passive or active targeting. In this study, we tuned the CCPM stability by using bifunctional or trifunctional cross-linkers and varying the cross-linkable polymer block length. For CCPMs, amphiphilic thiol-reactive polypept(o)ides of polysarcosine-block-poly(S-ethylsulfonyl-l-cysteine) [pSar-b-pCys(SO2Et)] were employed. While the pCys(SO2Et) chain lengths varied from Xn = 17 to 30, bivalent (derivatives of dihydrolipoic acid) and trivalent (sarcosine/cysteine pentapeptide) cross-linkers have been applied. Asymmetrical flow field-flow fraction (AF4) displayed the absence of aggregates in human plasma, yet for non-cross-linked PM and CCPMs cross-linked with dihydrolipoic acid at [pCys(SO2Et)]17, increasing the cross-linking density or the pCys(SO2Et) chain lengths led to stable CCPMs. Interestingly, circulation time and biodistribution in mice of non-cross-linked and bivalently cross-linked CCPMs are comparable, while the trivalent peptide cross-linkers enhance the circulation half-life from 11 to 19 h.

Tailored Beta-Lapachone Nanomedicines for Cancer-Specific Therapy

Nanotechnology shows the power to improve efficacy and reduce the adverse effects of anticancer agents. As a quinone-containing compound, beta-lapachone (LAP) is widely employed for targeted anticancer therapy under hypoxia. The principal mechanism of LAP-mediated cytotoxicity is believed due to the continuous generation of reactive oxygen species with the aid of NAD(P)H: quinone oxidoreductase 1 (NQO1). The cancer selectivity of LAP relies on the difference between NQO1 expression in tumors and that in healthy organs. Despite this, the clinical translation of LAP faces the problem of narrow therapeutic window that is challenging for dose regimen design. Herein, the multifaceted anticancer mechanism of LAP is briefly introduced, the advance of nanocarriers for LAP delivery is reviewed, and the combinational delivery approaches to enhance LAP potency in recent years are summarized. The mechanisms by which nanosystems boost LAP efficacy, including tumor targeting, cellular uptake enhancement, controlled cargo release, enhanced Fenton or Fenton-like reaction, and multidrug synergism, are also presented. The problems of LAP anticancer nanomedicines and the prospective solutions are discussed. The current review may help to unlock the potential of cancer-specific LAP therapy and speed up its clinical translation.

Targeting endosomal receptors, a new direction for polymers in nanomedicine

In this perspective, we outline a new opportunity for exploiting nanoparticle delivery of antagonists to target G-protein coupled receptors localized in intracellular compartments. We discuss the specific example of antagonizing endosomal receptors involved in pain to develop long-lasting analgesics but also outline the broader application potential of this delivery approach. We discuss the materials used to target endosomal receptors and indicate the design requirements for future successful applications.

Water-Soluble Gd(III)-Porphyrin Complexes Capable of Both Photosensitization and Relaxation Enhancement

With the aim of developing more stable Gd(III)-porphyrin complexes, two types of ligands 1 and 2 with carboxylic acid anchors were synthesized. Due to the N-substituted pyridyl cation attached to the porphyrin core, these porphyrin ligands were highly water-soluble and formed the corresponding Gd(III) chelates, Gd-1 and Gd-2. Gd-1 was sufficiently stable in neutral buffer, presumably due to the preferred conformation of the carboxylate-terminated anchors connected to nitrogen in the meta position of the pyridyl group helping to stabilize Gd(III) complexation by the porphyrin center. ¹H NMRD (nuclear magnetic relaxation dispersion) measurements on Gd-1 revealed high longitudinal water proton relaxivity (r₁ = 21.2 mM^-1 s^-1 at 60 MHz and 25 °C), which originates from slow rotational motion resulting from aggregation in aqueous solution. Under visible light irradiation, Gd-1 showed extensive photoinduced DNA cleavage in line with efficient photoinduced singlet oxygen generation. Cell-based assays revealed no significant dark cytotoxicity of Gd-1, while it showed sufficient photocytotoxicity on cancer cell lines under visible light irradiation. These results indicate the potential of this Gd(III)-porphyrin complex (Gd-1) as a core for the development of bifunctional systems acting as an efficient photodynamic therapy photosensitizer (PDT-PS) with magnetic resonance imaging (MRI) detection capabilities.

Complex Structures Made Simple - Continuous Flow Production of Core Cross-Linked Polymeric Micelles for Paclitaxel Pro-Drug-Delivery

Translating innovative nanomaterials to medical products requires efficient manufacturing techniques that enable large-scale high-throughput synthesis with high reproducibility. Drug carriers in medicine embrace a complex subset of tasks calling for multifunctionality. Here, the synthesisof pro-drug-loaded core cross-linked polymeric micelles (CCPMs) in a continuous flow processis reported, which combines the commonly separated steps of micelle formation, core cross-linking, functionalization, and purification into a single process. Redox-responsive CCPMs are formed from thiol-reactive polypept(o)ides of polysarcosine-block-poly(S-ethylsulfonyl-l-cysteine) and functional cross-linkers based on dihydrolipoic acid hydrazide for pH-dependent release of paclitaxel. The precisely controlled microfluidic process allows the production of spherical micelles (D_h  = 35 nm) with low polydispersity values (PDI < 0.1) while avoiding toxic organic solvents and additives with unfavorable safety profiles. Self-assembly and cross-linking via slit interdigital micromixers produces 350-700 mg of CCPMs/h per single system, while purification by online tangential flow filtration successfully removes impurities (unimer ≤ 0.5%). The formed paclitaxel-loaded CCPMs possess the desired pH-responsive release profile, display stable drug encapsulation, an improved toxicity profile compared to Abraxane (a trademark of Bristol-Myers Squibb), and therapeutic efficiency in the B16F1-xenotransplanted zebrafish model. The combination of reactive polymers, functional cross-linkers, and microfluidics enables the continuous-flow synthesis of therapeutically active CCPMs in a single process.

Enhanced lysosomal escape of cell penetrating peptide-functionalized metal-organic frameworks for co-delivery of survivin siRNA and oridonin

In recent years, small interfering RNA (siRNA) has been widely used in the treatment of human diseases, especially tumors, and has shown great appeal. However, the clinical application of siRNA faces several challenges. Insufficient efficacy, poor bioavailability, poor stability, and lack of responsiveness to a single therapy are the main problems affecting tumor therapy. Here, we designed a cell-penetrating peptide (CPP)-modified metal organic framework nanoplatform (named PEG-CPP33@ORI@survivin siRNA@ZIF-90, PEG-CPP33@NPs) for targeted co-delivery of oridonin (ORI), a natural anti-tumor active ingredient) and survivin siRNA in vivo. This can improve the stability and bioavailability of siRNA and the efficacy of siRNA monotherapy. The high drug-loading capacity and pH-sensitive properties of zeolite imidazolides endowed the PEG-CPP33@NPs with lysosomal escape abilities. The Polyethylene glycol (PEG)-conjugated CPP (PEG-CPP33) coating significantly improved the uptake in the PEG-CPP33@NPs in vitro and in vivo. The results showed that the co-delivery of ORI and survivin siRNA greatly enhanced the anti-tumor effect of PEG-CPP33@NPs, demonstrating the synergistic effect between ORI and survivin siRNA. In summary, the novel targeted nanobiological platform loaded with ORI and survivin siRNA presented herein showed great advantages in cancer therapy, and provides an attractive strategy for the synergistic application of chemotherapy and gene therapy.

A Supramolecular Assembly Strategy for Hydrophilic Drug Delivery towards Synergistic Cancer Treatment

To improve the drug loading, tumor targeting, and delivery simplicity of hydrophilic drugs, we propose a supramolecular assembly strategy that potentially benefits a wide range of hydrophilic drug delivery. Firstly, we choose a hydrophilic drug (tirapazamine) as a model drug to directly co-assemble with chlorin e6 (Ce6) at different molar ratios, and systematically evaluate the resultant Ce6-tirapazamine nanoparticles (CT NPs) in aspects of size distribution, polydispersity, morphology, optical properties and molecular dynamics simulation. Based on the assembling facts between Ce6 and tirapazamine, we summarize a plausible rule of the supramolecular assembly for hydrophilic drugs. To validate our findings, more drugs with increasing hydrophilicity, such as temozolomide, gemcitabine hydrochloride and 5-azacytidine, successfully co-assemble with Ce6 into nanostructures by following similar assembling behaviors, demonstrating that our assembling rule may guide a wide range of hydrophilic drug delivery. Next, the combination of Ce6 and tirapazamine was chosen as the representative to investigate the anti-tumor activities of the supramolecular assemblies. CT NPs showed synergistic anti-tumor efficacy, increased tumor accumulation and significant tumor progression and metastasis inhibition in tumor-bearing mice. We anticipate that the supramolecular assembly mechanism will provide broad guidance for developing easy-to-make but functional nanomedicines. STATEMENT OF SIGNIFICANCE: Although thousands of nanomedicines have been developed, only a few have been approved for clinical use. The manufacturing complexity significantly hinders the "bench-to-bed" translation of nanomedicines. Hence, we need to rethink how to conduct research on translational nanomedicines by avoiding more and more complex chemistry and complicated nanostructures. Here, we summarize a plausible rule according to multiple supramolecular assembly pairs and propose a supramolecular assembly strategy that can improve the drug loading, tumor targeting, and manufacturing simplicity of nanomedicine for hydrophilic drugs. The supramolecular assembly strategy would guide a broader range of drug delivery to provide a new paradigm for developing easy-to-make but multifunctional nanoformulations for synergistic cancer treatment.

Improved targeting delivery of WED-load immunoliposomes modified with SP-A mAb for the treatment of pulmonary fibrosis

The epithelial-mesenchymal transition (EMT) of type Ⅱ alveolar epithelial cells (AECS Ⅱ) induced by transforming growth factor (TGF-β1) is a primary pathogenesis of pulmonary fibrosis (PF). To augment the therapeutic potency of wedelolactone (WED) for PF, herein, pulmonary surfactant protein A (SP-A) specifically expressed on AECS Ⅱ was selected as the targeted receptor. Immunoliposomes modified with SP-A monoclonal antibody (SP-A mAb), novel anti-PF drug delivery systems, were developed and investigated in vivo and in vitro. In vivo fluorescence imaging technique was performed to evaluate the pulmonary-targeting effects of immunoliposomes. The result showed that immunoliposomes accumulated more in the lung, compared with non-modified nanoliposomes. Fluorescence detection methods and flow cytometry were used to investigate the function of SP-A mAb and the cellular uptake efficiency of WED-ILP in vitro. SP-A mAb enabled the immunoliposomes to specifically target the A549 cells and increased uptake more effectively. The mean fluorescence intensity (MFI) of cells treated with the targeted immunoliposomes was about 1.4-fold higher than that of cells treated with regular nanoliposomes. The cytotoxicity of nanoliposomes was assessed by the MTT assay, which demonstrated that blank nanoliposomes have no significant effect on A549 cell proliferation even at the SPC concentration of 1000 µg/mL. Additionally, in vitro pulmonary fibrosis model was established to further investigate the anti-pulmonary fibrosis effect of WED-ILP. WED-ILP significantly (**P < 0.01) inhibited the proliferation of A549 cells stimulated by TGF-β1 indicating that WED-ILP has great potential for the clinical treatment of PF.

Highlighting the Undetectable - Fluorescence Molecular Imaging in Gastrointestinal Endoscopy

Flexible high-definition white-light endoscopy is the current gold standard in screening for cancer and its precursor lesions in the gastrointestinal tract. However, miss rates are high, especially in populations at high risk for developing gastrointestinal cancer (e.g., inflammatory bowel disease, Lynch syndrome, or Barrett's esophagus) where lesions tend to be flat and subtle. Fluorescence molecular endoscopy (FME) enables intraluminal visualization of (pre)malignant lesions based on specific biomolecular features rather than morphology by using fluorescently labeled molecular probes that bind to specific molecular targets. This strategy has the potential to serve as a valuable tool for the clinician to improve endoscopic lesion detection and real-time clinical decision-making. This narrative review presents an overview of recent advances in FME, focusing on probe development, techniques, and clinical evidence. Future perspectives will also be addressed, such as the use of FME in patient stratification for targeted therapies and potential alliances with artificial intelligence. KEY MESSAGES: • Fluorescence molecular endoscopy is a relatively new technology that enables safe and real-time endoscopic lesion visualization based on specific molecular features rather than on morphology, thereby adding a layer of information to endoscopy, like in PET-CT imaging. • Recently the transition from preclinical to clinical studies has been made, with promising results regarding enhancing detection of flat and subtle lesions in the colon and esophagus. However, clinical evidence needs to be strengthened by larger patient studies with stratified study designs. • In the future fluorescence molecular endoscopy could serve as a valuable tool in clinical workflows to improve detection in high-risk populations like patients with Barrett's esophagus, Lynch syndrome, and inflammatory bowel syndrome, where flat and subtle lesions tend to be malignant up to five times more often. • Fluorescence molecular endoscopy has the potential to assess therapy responsiveness in vivo for targeted therapies, thereby playing a role in personalizing medicine. • To further reduce high miss rates due to human and technical factors, joint application of artificial intelligence and fluorescence molecular endoscopy are likely to generate added value.

Nanotechnology and cancer therapeutics: delivering on the hype?

Nanoparticle drug delivery systems are a promising development in cancer therapy for reducing toxicity and drug resistance, whilst improving precision targeting. Several types of nanotechnology are in development, with some receiving market approval and others proving difficult to translate to the bedside. [Formula: see text].

Exploiting active nuclear import for efficient delivery of Auger electron emitters into the cell nucleus

BACKGROUND

The most attractive features of Auger electrons (AEs) in cancer therapy are their extremely short range and sufficiently high linear energy transfer (LET) for a majority of them. The cytotoxic effects of AE emitters can be realized only in close vicinity to sensitive cellular targets and they are negligible if the emitters are located outside the cell. The nucleus is considered the compartment most sensitive to high LET particles. Therefore, the use of AE emitters could be most useful in specific recognition of a cancer cell and delivery of AE emitters into its nucleus.

PURPOSE

This review describes the studies aimed at developing effective anticancer agents for the delivery of AE emitters to the nuclei of target cancer cells. The use of peptide-based conjugates, nanoparticles, recombinant proteins, and other constructs for AE emitter targeted intranuclear delivery as well as their advantages and limitations are discussed.

CONCLUSION

Transport from the cytoplasm to the nucleus along with binding to the cancer cell is one of the key stages in the delivery of AE emitters; therefore, several constructs for exploitation of this transport have been developed. The transport is carried out through a nuclear pore complex (NPC) with the use of specific amino acid nuclear localization sequences (NLS) and carrier proteins named importins, which are located in the cytosol. Therefore, the effectiveness of NLS-containing delivery constructs designed to provide energy-dependent transport of AE emitter into the nuclei of cancer cells also depends on their efficient entry into the cytosol of the target cell.

Liposome-Encapsulated Melphalan Exhibits Potent Antimyeloma Activity and Reduced Toxicity

Multiple myeloma (MM), a plasma cell cancer in bone marrow, remains an incurable disease. Melphalan, an alkylating agent, is a conventional anticancer drug that is still widely used for MM treatment in clinics. However, melphalan-induced organ toxicity and side effects are common. In this study, we loaded melphalan into a liposomal capsule and constituted liposomal melphalan (liposomal MEL). Liposomal MEL particles were approximately 120 nm in size and stable in vitro. The liposomal particles could be effectively taken up by MM cells. In vitro cytotoxicity assays using MM cell lines and primary MM cells showed that liposomal MEL exhibited similar anti-MM activity compared to an equivalent amount of free melphalan (free MEL) compound. In animal models, liposomal particles had bone marrow enrichment and prolonged half-life in vivo. Liposomal MEL exposure resulted in less liver and colon organ toxicity than exposure to an equivalent amount of free MEL-treated mice. Importantly, liposomal MEL had potent anti-MM activity in vivo in a human MM xenograft mouse model. Overall, our findings suggested that liposome-encapsulated melphalan was an effective drug modification of the melphalan compound and showed promise in MM treatment.

Role of Tunable Gold Nanostructures in Cancer Nanotheranostics: Implications on Synthesis, Toxicity, Clinical Applications and Their Associated Opportunities and Challenges

The existing diagnosis and treatment modalities have major limitations related to their precision and capability to understand several stages of disease development. A superior therapeutic system consists of a multifunctional approach in early diagnosis of the disease with a simultaneous progressive cure, using a precise medical approach towards complex treatment. These challenges can be addressed via nanotheranostics and explore suitable approaches to improve health care. Nanotechnology in combination with theranostics as an unconventional platform paved the way for developing novel strategies and modalities leading to diagnosis and therapy for complex disease conditions, ranging from acute to chronic levels. Among the metal nanoparticles, gold nanoparticles are being widely used for theranostics due to their inherent non-toxic nature and plasmonic properties. The unique optical and chemical properties of plasmonic metal nanoparticles along with theranostics have led to a promising era of plausible early detection of disease conditions, and they enable real-time monitoring with enhanced non-invasive or minimally invasive imaging of several ailments. This review aims to highlight the improvement and advancement brought to nanotheranostics by gold nanoparticles in the past decade. The clinical use of the metal nanoparticles in nanotheranostics is explained, along with the future perspectives on addressing the key applications related to diagnostics and therapeutics, respectively. The scope of gold nanoparticles and their realistic potential to design a sophisticated theranostic system is discussed in detail, along with their implications in clinical advancements which are the needs of the hour. The review concluded with the challenges, opportunities, and implications on translational potential of using gold nanoparticles in nanotheranostics.