Perspectives for Improving the Tumor Targeting of Nanomedicine via the EPR Effect in Clinical Tumors

A tumor targeted nano micelle carrying astragaloside IV for combination treatment of bladder cancer

Immune checkpoint inhibitors (ICIs) are effective agents for tumor immunotherapy. However, their clinical effectiveness is unsatisfactory due to off-target effects and a suppressive immune microenvironment. This study developed a nanodrug delivery system for bladder cancer (BCa) using PCL-MPEG and PCL-PEG-CHO to synthesize internal hydrophobic and external hydrophilic micelles (PP) that encapsulated water-insoluble astragaloside IV (PPA). The aldehyde group on the surface of PPA reacted with the amino group of aPD-L1, allowing the decoration of this antibody on the surface of the micelles. The resultingPPA@aPD-L1effectively piggybacked astragaloside IV and aPD-L1 antibody. These findings suggest that PPA@aPD-L1 is relatively stable in circulation and efficiently binds to BCa cells with the aid of aPD-L1. Additionally, this strategy prolongs the drug's retention time in tumors. Compared to PBS, PP, and PPA with PPA + aPD-L1 groups, PPA@aPD-L1significantly prolonged the survival of mice with BCa and reduced tumor volume. Mechanistic studies showed that PPA inhibited the NF-κB and STAT3 signaling pathways in tumor cells. Additionally, PPA@aPD-L1increased IFN-γ and decreased IL-10 expression in bladder tumors, affecting the number and type of intratumorally infiltrating T cells. Our study presents a simple and effective drug delivery system that combines herbal monomers with ICIs. It has demonstrated a potent ability to suppress tumor growth and holds potential for future applications.

Nano-Delivery of Immunogenic Cell Death Inducers and Immune Checkpoint Blockade Agents: Single-Nanostructure Strategies for Enhancing Immunotherapy

Cancer immunotherapy has revolutionized oncology by harnessing the patient's immune system to target and eliminate cancer cells. However, immune checkpoint blockades (ICBs) face limitations such as low response rates, particularly in immunologically 'cold' tumors. Enhancing tumor immunogenicity through immunogenic cell death (ICD) inducers and advanced drug delivery systems represents a promising solution. This review discusses the development and application of various nanocarriers, including polymeric nanoparticles, liposomes, peptide-based nanoparticles, and inorganic nanoparticles, designed to deliver ICD inducers and ICBs effectively. These nanocarriers improve therapeutic outcomes by converting cold tumors into hot tumors, thus enhancing immune responses and reducing systemic toxicity. By focusing on single-nanoparticle systems that co-deliver both ICD inducers and ICBs, this review highlights their potential in achieving higher drug concentrations at tumor sites, improving pharmacokinetics and pharmacodynamics, and facilitating clinical translation. Future research should aim to optimize these nanocarrier systems for better in vivo performance and clinical applications, ultimately advancing cancer immunotherapy.

Mathematical modeling of heat transfer in tissues with skin tumor during thermotherapy

The study of thermal therapy to tumors and the response of living cells to this therapy used to treat tumor is very important due to the complexity of heat transfer in biological tissues. In the past few years, there has been a growing interest among clinicians, mathematicians, and engineers regarding the use of computational and mathematical methods to simulate biological systems. Numerous medical proceedings also employ mathematical modeling and engineering techniques as a means to guarantee their safety and evaluate the associated risks effectively. This manuscript provides an analytical solution used for the first time to study the mechanism of biological thermal response during heat therapy on spheroidal skin tumor. The proposed method used a generalized thermoelasticity model with one relaxation time. The influence of relaxation times on the responses of diseased and healthy tissues is studied and interpreted graphically. Also, the impact of different laser irradiance on the thermal profile of the malignant tumor cells over a period of 2 minutes is interpreted graphically. To investigate the transfer of heat within biological tissues during the thermal therapy, the Laplace transform and inverse Laplace transform methods were applied. A comparison of the present generalized thermoelasticity model and different models based on Pennes bioheat transfer PBT shows that our proposed model yields more realistic and accurate predictions. The current model can be used to explain various therapeutic methods.

Doxorubicin loaded thermostable nanoarchaeosomes: a next-generation drug carrier for breast cancer therapeutics

Breast cancer has a poor prognosis due to the toxic side effects associated with high doses of chemotherapy. Liposomal drug encapsulation has resulted in clinical success in enhancing chemotherapy tolerability. However, the formulation faces severe limitations with a lack of colloidal stability, reduced drug efficiency, and difficulties in storage conditions. Nanoarchaeosomes (NA) are a new generation of highly stable nanovesicles composed of the natural ether lipids extracted from archaea. In our study, we synthesized and characterized the NA, evaluated their colloidal stability, drug release potential, and anticancer efficacy. Transmission electron microscopy images have shown that the NA prepared from the hyperthermophilic archaeon Aeropyrum pernix K1 was in the size range of 61 ± 3 nm. The dynamic light scattering result has confirmed that the NA were stable at acidic pH (pH 4) and high temperature (70 °C). The NA exhibited excellent colloidal stability for 50 days with storage conditions at room temperature. The cell viability results have shown that the pure NA did not induce cytotoxicity in NIH 3T3 fibroblast cells and are biocompatible. Then NA were loaded with doxorubicin (NAD), and FTIR and UV-vis spectroscopy results have confirmed high drug loading efficiency of 97 ± 1% with sustained drug release for 48 h. The in vitro cytotoxicity studies in MCF-7 breast cancer cell lines showed that NAD induced cytotoxicity at less than 10 nM concentration. Fluorescence-activated cell sorting (FACS) results confirmed that NAD induced late apoptosis in nearly 92% of MCF-7 cells and necrosis in the remaining cells with cell cycle arrest at the G0/G1 phase. Our results confirmed that the NA could be a potential next-generation carrier with excellent stability, high drug loading efficiency, sustained drug release ability, and increased therapeutic efficacy, thus reducing the side effects of conventional drugs.

An FOF1-ATPase motor-embedded chromatophore as a nanorobot for overcoming biological barriers and targeting acidic tumor sites

Despite the booming progress of anticancer nanomedicines in the past two decades, precise tumor-targetability and sufficient tumor-accumulation are less successful and still require further research. To tackle this challenge, herein we present a biomolecular motor (FOF1-ATPase)-embedded chromatophore as nanorobot to efficiently overcome biological barriers, and thoroughly investigate its chemotactic motility, tumor-accumulation ability and endocytosis. Chromatophores embedded with FOF1-ATPase motors were firstly extracted from Thermus thermophilus, then their properties were fully characterized. Specifically, two microfluidic platforms (laminar flow microchip and tumor microenvironment (TME) microchip) were designed and developed to fully investigate the motility, tumor-accumulation ability and endocytosis of the chromatophore nanorobot (CN). The results from the laminar flow microchip indicated that the obtained CN possessed the strongly positive chemotaxis towards protons. And the TME microchip experiments verified that the CN had a desirable tumor-accumulation ability. Cellular uptake experiments demonstrated that the CN efficiently promoted the endocytosis of the fluorescence DiO into the HT-29 cells. And the in vivo studies revealed that the intravenously administered CN exhibited vigorous tumor-targetability and accumulation ability as well as highly efficient antitumor efficacy. All the results suggested that FOF1-ATPase motors-embedded CN could be promising nanomachines with powerful self-propulsion for overcoming physiological barriers and tumor-targeted drug delivery. STATEMENT OF SIGNIFICANCE: In this study, we demonstrated that FOF1-ATPase-embedded chromatophore nanorobots exhibit a strong proton chemotaxis, which not only plays a key role in tumor-targetability and accumulation, but also promotes tumor tissue penetration and internalization. The results of in vitro and in vivo studies indicated that drug-loaded chromatophore nanorobots are capable to simultaneously accomplish tumor-targeting, accumulation, penetration and internalization for enhanced tumor therapy. Our study provides a fundamental basis for further study on FOF1-ATPase-embedded chromatophore as tumor-targeting drug delivery systems that have promising clinical applications. It offers a new and more efficient delivery vehicle for cancer related therapeutics.

Multi-functional nanomedicines for combinational cancer immunotherapy that transform cold tumors to hot tumors

INTRODUCTION

Currently, cancer immunotherapy is widely used as a groundbreaking method that can completely cure advanced cancers. However, this new immunotherapy has the challenge of low patient response, which is often due to many patients' tumors having an immunosuppressive environment, known as cold tumors.

AREAS COVERED

This review aims to introduce various nanomedicine-derived combinational cancer immunotherapy that can transform cold tumor into hot tumors. Initially, we discuss new technologies for combinational immunotherapy based on multifunctional nanomedicines that can deliver combinational immunogenic cell death (ICD) inducers, immune checkpoint blockades (ICBs) and immune modulators (IMs) to targeted tumor tissues at the same time. Ultimately, we highlight how multifunctional nanomedicines for combinational cancer immunotherapy can be used to transform cold tumor into hot tumors against advanced cancers.

EXPERT OPINION

Nanomedicine-derived combinational cancer immunotherapy for delivering multiple ICD inducers, ICBs, and IMs at the same time is recognized as a new potential technology that can activate tumor immunity and simultaneously increase the therapeutic efficacy of immune cells that can transform effectively the cold tumors into hot tumors. Finally, nanomedicine-derived combinational cancer immunotherapy can solve the serious problems of low therapeutic efficacy that occurs when treating single drug or simple combinational drugs in cancer immunotherapy.

Unleashing the Potential of Camptothecin: Exploring Innovative Strategies for Structural Modification and Therapeutic Advancements

Camptothecin (CPT) is a potent anti-cancer agent targeting topoisomerase I (TOP1). However, CPT has poor pharmacokinetic properties, causes toxicities, and leads to drug resistance, which limit its clinical use. In this paper, to review the current state of CPT research. We first briefly explain CPT's TOP1 inhibition mechanism and the key hurdles in CPT drug development. Then we examine strategies to overcome CPT's limitations through structural modifications and advanced delivery systems. Though modifications alone seem insufficient to fully enhance CPT's therapeutic potential, structure-activity relationship analysis provides insights to guide optimization of CPT analogs. In comparison, advanced delivery systems integrating controlled release, imaging capabilities, and combination therapies via stimulus-responsive linkers and targeting moieties show great promise for improving CPT's pharmacological profile. Looking forward, multifaceted approaches combining selective CPT derivatives with advanced delivery systems, informed by emerging biological insights, hold promise for fully unleashing CPT's anti-cancer potential.

Comparison of Tumor Non-specific and PD-L1 Specific Imaging by Near-Infrared Fluorescence/Cerenkov Luminescence Dual-Modality In-situ Imaging

Background

Labeled antibodies are excellent imaging agents in oncology to non-invasively visualize cancer-related antigens expression levels. However, tumor tracer uptake (TTU) of specific antibodies in-vivo may be inferior to non-specific IgG in some cases.

Objectives

To explore factors affecting labeled antibody visualization by PD-L1 specific and non-specific imaging of nude mouse tumors.

Methods

TTU was observed in RKO model on Cerenkov luminescence (CL) and near-infrared fluorescence (NIRF) imaging of radionuclide 131I or NIRF dyes labeled Atezolizumab and IgG. A mixture of NIRF dyes labeled Atezolizumab and 131I-labeled IgG was injected, and TTU was observed in the RKO and HCT8 model by NIRF/CL dual-modality in-situ imaging. TTU were observed by 131I-labeled Atezolizumab and IgG in-vitro distribution.

Results

Labeled IgG concentrated more in tumors than Atezolizumab. NIRF/CL imaging in 24 to 168 h showed that TTU gradually decreased over time, which decreased more slowly on CL imaging compared to NIRF imaging. The distribution data in-vitro showed that TTU of 131I-labeled IgG was higher than that of 131I-labeled Atezolizumab at any time point.

Conclusion

Non-specific IgG may not be suitable as a control for Atezolizumab in comparing tumor PD-L1 expression in nude mice via labeled antibody optical imaging under certain circumstances.

Ciprofloxacin and Norfloxacin Hybrid Compounds: Potential Anticancer Agents

BACKGROUND

The concept of utilizing drug repurposing/repositioning in the development of hybrid molecules is an important strategy in drug discovery. Fluoroquinolones, a class of antibiotics, have been reported to exhibit anticancer activities. Although anticancer drug development is achieving some positive outcomes, there is still a need to develop new and effective anticancer drugs. Some limitations associated with most of the available anticancer drugs are drug resistance and toxicity, poor bio-distribution, poor solubility, and lack of specificity, thereby reducing their therapeutic outcomes.

OBJECTIVES

Fluoroquinolones, a known class of antibiotics, have been explored by hybridizing them with other pharmacophores and evaluating their anticancer activity in silico and in vitro. Hence, this review provides an update on new anticancer drugs containing fluoroquinolones moiety, Ciprofloxacin and Norfloxacin between 2020 and 2023, their structural relationship activity, and the future strategies to develop potent chemotherapeutic agents.

METHODS

Fluoroquinolones were mostly hybridized via the N-4 of the piperazine ring on position C-7 with known pharmacophores characterized, followed by biological studies to evaluate their anticancer activity.

RESULTS

The hybrid molecules displayed promising and interesting anticancer activities. Factors such as the nature of the linker, the presence of electron-withdrawing groups, nature, and position of the substituents influenced the anticancer activity of the synthesized compounds.

CONCLUSION

The hybrids were selective towards some cancer cells. However, further in vivo studies are needed to fully understand their mode of action.

HSA-ZW800-PEG for Enhanced Optophysical Stability and Tumor Targeting

Small molecule fluorophores often face challenges such as short blood half-life, limited physicochemical and optical stability, and poor pharmacokinetics. To overcome these limitations, we conjugated the zwitterionic near-infrared fluorophore ZW800-PEG to human serum albumin (HSA), creating HSA-ZW800-PEG. This conjugation notably improves chemical, physical, and optical stability under physiological conditions, addressing issues commonly encountered with small molecules in biological applications. Additionally, the high molecular weight and extinction coefficient of HSA-ZW800-PEG enhances biodistribution and tumor targeting through the enhanced permeability and retention effect. The unique distribution and elimination dynamics, along with the significantly extended blood half-life of HSA-ZW800-PEG, contribute to improved tumor targetability in both subcutaneous and orthotopic xenograft tumor-bearing animal models. This modification not only influences the pharmacokinetic profile, affecting retention time and clearance patterns, but also enhances bioavailability for targeting tissues. Our study guides further development and optimization of targeted imaging agents and drug-delivery systems.

Recent Advances in Micro- and Nano-Drug Delivery Systems Based on Natural and Synthetic Biomaterials

Polymeric drug delivery technology, which allows for medicinal ingredients to enter a cell more easily, has advanced considerably in recent decades. Innovative medication delivery strategies use biodegradable and bio-reducible polymers, and progress in the field has been accelerated by future possible research applications. Natural polymers utilized in polymeric drug delivery systems include arginine, chitosan, dextrin, polysaccharides, poly(glycolic acid), poly(lactic acid), and hyaluronic acid. Additionally, poly(2-hydroxyethyl methacrylate), poly(N-isopropyl acrylamide), poly(ethylenimine), dendritic polymers, biodegradable polymers, and bioabsorbable polymers as well as biomimetic and bio-related polymeric systems and drug-free macromolecular therapies have been employed in polymeric drug delivery. Different synthetic and natural biomaterials are in the clinical phase to mitigate different diseases. Drug delivery methods using natural and synthetic polymers are becoming increasingly common in the pharmaceutical industry, with biocompatible and bio-related copolymers and dendrimers having helped cure cancer as drug delivery systems. This review discusses all the above components and how, by combining synthetic and biological approaches, micro- and nano-drug delivery systems can result in revolutionary polymeric drug and gene delivery devices.

Harnessing Nanomedicine to Potentiate the Chemo-Immunotherapeutic Effects of Doxorubicin and Alendronate Co-Encapsulated in Pegylated Liposomes

Encapsulation of Doxorubicin (Dox), a potent cytotoxic agent and immunogenic cell death inducer, in pegylated (Stealth) liposomes, is well known to have major pharmacologic advantages over treatment with free Dox. Reformulation of alendronate (Ald), a potent amino-bisphosphonate, by encapsulation in pegylated liposomes, results in significant immune modulatory effects through interaction with tumor-associated macrophages and activation of a subset of gamma-delta T lymphocytes. We present here recent findings of our research work with a formulation of Dox and Ald co-encapsulated in pegylated liposomes (PLAD) and discuss its pharmacological properties vis-à-vis free Dox and the current clinical formulation of pegylated liposomal Dox. PLAD is a robust formulation with high and reproducible remote loading of Dox and high stability in plasma. Results of biodistribution studies, imaging with radionuclide-labeled liposomes, and therapeutic studies as a single agent and in combination with immune checkpoint inhibitors or gamma-delta T lymphocytes suggest that PLAD is a unique product with distinct tumor microenvironmental interactions and distinct pharmacologic properties when compared with free Dox and the clinical formulation of pegylated liposomal Dox. These results underscore the potential added value of PLAD for chemo-immunotherapy of cancer and the relevance of the co-encapsulation approach in nanomedicine.