Regulation of transport pathways in tumor vessels: role of tumor type and microenvironment

pH-responsive carbohydrate polymer-based nanoparticles in cancer therapy

Using the specific features of the tumor microenvironment (TME) for the development and design of novel nanomaterials can improve the capacity in tumor suppression. One of the prominent features of the TME is the mild acidic pH. Therefore, the development of pH-responsive nanoparticles can lead to the release of cargo and therapeutics at the tumor site, improving the selectivity and specificity. The materials used for the development of nanoparticles should possess a number of unique features including biocompatibility and anti-cancer activity. Hence, a special attention has been directed towards the use of carbohydrate polymers in the development of nanoparticles. The carbohydrate polymers can develop smart nanoparticles respond to the pH in TME to increase targeting ability and provide controlled drug release. Such approach is also beneficial in decreasing the side effects of systemic chemotherapy. The pH-responsive nanoparticles developed from carbohydrate polymers can be also used for the combination chemotherapy/immunotherapy/phototherapy of cancer. Furthermore, these nanoparticles demonstrate theranostic application capable of cancer diagnosis and therapy. Further attention to the large-scale production, biocompatibility and long-term safety of carbohydrate polymer-based pH-responsive nanoparticles should be directed to improve the clinical translation in the treatment of cancer patients.

Deciphering a crosstalk between biological cues and multifunctional nanocarriers in lung cancer therapy

In recent years, the utilization of nanocarriers has significantly broadened across a diverse spectrum of biomedical applications. However, the clinical translation of these tiny carriers is limited and encounters hurdles, particularly in the intricate landscape of the tumor microenvironment. Lung cancer poses unique hurdles for nanocarrier design. Multiple physiological barriers hinder the efficient drug delivery to the lungs, such as the complex anatomy of the lung, the presence of mucus, immune responses, and rapid clearance mechanisms. Overcoming these obstacles necessitates a targeted approach that minimizes off-target effects while effectively penetrating nanoparticles/cargo into specific lung tissues or cells. Furthermore, understanding the cellular uptake mechanisms of these nano carriers is also essential. This knowledge aids in developing nanocarriers that efficiently enter cells and transfer their payload for the most effective therapeutic outcome. Hence, a thorough understanding of biological cues becomes crucial in designing multifunctional nanocarriers tailored for treating lung cancer. This review explores the essential biological cues critical for developing a flexible nanocarrier specifically intended to treat lung cancer. Additionally, it discusses advancements in nanotheranostics in lung cancer.

Dual-imaging nanoparticles based on surface-modified magnetic nanoparticles and biodegradable photoluminescent polymers

Theranostic nanoparticles, which combine diagnostic and therapeutic capabilities, have gained significant interest in disease management. We previously developed dual-imaging enabled cancer-targeting nanoparticles (DICT-NPs) composed of a biodegradable photoluminescent polymer (BPLP) and iron oxide-based superparamagnetic nanoparticles (MNPs). While DICT-NPs demonstrated cytocompatibility, magnetic targeting, and imaging capabilities, their fluorescence was inconsistent due to quenching by the MNP core and inefficient BPLP grafting. To address these limitations, we modified the MNP surface with silane, hydroxyapatite, or silane-coupled azide coatings before conjugating with BPLP. The resulting surface-modified DICT-NPs (mDICT-NPs) ranged in size from 200-350 nm and were cyto-compatible with human dermal fibroblasts and normal human prostate epithelial cells. Surface modifications and BPLP conjugation did not affect the superparamagnetic properties of the nanoparticles but enhanced fluorescence by ∼50% compared to the original DICT-NPs. Hydroxyapatite-modified DICT-NPs exhibited significant improvements, including sustained drug release of Paclitaxel and Docetaxel (71% and 68%, respectively, over 21 days), dose-dependent tumor cell uptake in melanoma, thyroid, and prostate cancer cells (with the highest uptake exceeding 60% at 500 μg/mL), and a reduction in cancer cell viability (less than 50% viability in TT thyroid cancer and KAT-4 cancer cell lines). These advancements represent a significant step in overcoming the fluorescence quenching issues associated with iron oxide-based magneto-fluorescent theranostic nanoparticle platforms, enhancing both their imaging and therapeutic potential in cancer treatment.

The pathways for nanoparticle transport across tumour endothelium

The active transport and retention principle is an alternative mechanism to the enhanced permeability and retention effect for explaining nanoparticle tumour delivery. It postulates that nanoparticles actively transport across tumour endothelial cells instead of passively moving through gaps between these cells. How nanoparticles transport across tumour endothelial cells remains unknown. Here we show that nanoparticles cross tumour endothelial cells predominantly using the non-receptor-based macropinocytosis pathway. We discovered that tumour endothelial cell membrane ruffles capture circulating nanoparticles, internalize them in intracellular vesicles and release them into the tumour interstitium. Tumour endothelial cells have a higher membrane ruffle density than healthy endothelium, which may partially explain the elevated nanoparticle tumour accumulation. Receptor-based endocytosis pathways such as clathrin-mediated endocytosis contribute to nanoparticle transport to a lesser extent. Nanoparticle size determines the degree of contribution for each pathway. Elucidating the nanoparticle transport mechanism is crucial for developing strategies to control nanoparticle tumour delivery.

Evaluation of blood-tumor barrier permeability and doxorubicin delivery in rat brain tumor models using additional focused ultrasound stimulation

Focused ultrasound (FUS) has emerged as a promising technique for temporarily disrupting the blood-brain barrier (BBB) and blood-tumor barrier (BTB) to enhance the delivery of therapeutic agents. Despite its potential, optimizing FUS to maximize drug delivery while minimizing adverse effects remains a significant challenge. In this study, we evaluated a novel FUS protocol that incorporates additional FUS stimulation without microbubbles (MBs) ("FUS protocol") prior to conventional BBB disruption with MBs ("BBBD protocol") in a rat brain tumor model (n = 35). This approach aimed to validate its effectiveness in enhancing BBB/BTB disruption and facilitating doxorubicin delivery. T1-weighted contrast-enhanced and dynamic contrast-enhanced (DCE) MRI demonstrated significant increases in signal intensity and permeability (Ktrans) in the tumor region under the "FUS + BBBD protocol", with 2.65-fold and 2.08-fold increases, respectively, compared to the non-sonicated contralateral region. These values were also elevated compared to the conventional "BBBD protocol" by 1.45-fold and 1.25-fold, respectively. Furthermore, doxorubicin delivery in the targeted region increased by 1.91-fold under the "FUS + BBBD protocol", compared to a 1.44-fold increase using the conventional "BBBD protocol". This novel FUS approach offers a promising, cost-effective strategy for enhancing drug delivery to brain tumors. While further studies are required to assess its applicability with different chemotherapeutics and tumor types, it holds significant potential for improving brain tumor treatment in both preclinical and clinical settings.

Translational nanorobotics breaking through biological membranes

In the dynamic realm of translational nanorobotics, the endeavor to develop nanorobots carrying therapeutics in rational in vivo applications necessitates a profound understanding of the biological landscape of the human body and its complexity. Within this landscape, biological membranes stand as critical barriers to the successful delivery of therapeutic cargo to the target site. Their crossing is not only a challenge for nanorobotics but also a pivotal criterion for the clinical success of therapeutic-carrying nanorobots. Nevertheless, despite their urgency, strategies for membrane crossing in translational nanorobotics remain relatively underrepresented in the scientific literature, signaling an opportunity for further research and innovation. This review focuses on nanorobots with various propulsion mechanisms from chemical and physical to hybrid mechanisms, and it identifies and describes four essential biological membranes that represent the barriers needed to be crossed in the therapeutic journey of nanorobots in in vivo applications. First is the entry point into the blood stream, which is the skin or mucosa or intravenous injection; next is the exit from the bloodstream across the endothelium to the target site; further is the entry to the cell through the plasma membrane and, finally, the escape from the lysosome, which otherwise destroys the cargo. The review also discusses design challenges inherent in translating nanorobot technologies to real-world applications and provides a critical overview of documented membrane crossings. The aim is to underscore the need for further interdisciplinary collaborations between chemists, materials scientists and chemical biologists in this vital domain of translational nanorobotics that has the potential to revolutionize the field of precision medicine.

Harnessing macrophage-drug conjugates for allogeneic cell-based therapy of solid tumors via the TRAIN mechanism

Treatment of solid tumors remains challenging and therapeutic strategies require continuous development. Tumor-infiltrating macrophages play a pivotal role in tumor dynamics. Here, we present a Macrophage-Drug Conjugate (MDC) platform technology that enables loading macrophages with ferritin-drug complexes. We first show that macrophages actively take up human heavy chain ferritin (HFt) in vitro via macrophage scavenger receptor 1 (MSR1). We further manifest that drug-loaded macrophages transfer ferritin to adjacent cancer cells through a process termed 'TRAnsfer of Iron-binding protein' (TRAIN). The TRAIN process requires direct cell-to-cell contact and an immune synapse-like structure. At last, MDCs with various anti-cancer drugs are formulated with their safety and anti-tumor efficacy validated in multiple syngeneic mice and orthotopic human tumor models via different routes of administration. Importantly, MDCs can be prepared in advance and used as thawed products, supporting their clinical applicability. This MDC approach thus represents a promising advancement in the therapeutic landscape for solid tumors.

Pathological angiogenesis was associated with cerebrovascular lesion and neurodegeneration in Alzheimer's disease

INTRODUCTION

We investigated the specific factors driving abnormal angiogenesis in Alzheimer's disease (AD) and its role in cerebrovascular lesions and neurodegeneration.

METHODS

We assessed cerebrovascular pathologies, amyloid-beta (Aβ), and tau pathologies in post mortem human brains and detected 12 angiogenic factors in cerebrospinal fluid (CSF) from the China Aging and Neurodegenerative Disease Initiative (CANDI) cohort.

RESULTS

We observed severe blood-brain barrier damage and elevated levels of the vascular marker CD31 in human AD brains, which had a stronger correlation with tau pathology than Aβ pathology. Consistently, only CSF pTau181 showed positive associations with CSF angiogenesis factors (soluble vascular endothelial growth factor receptor 2 [sVEGFR2], VEGF-C, VEGF-D, placental growth factor [PLGF], Angiopoietin2, and Serpin E1), but not CSF Aβ42/40. Additionally, higher levels of CSF sVEGFR1, soluble Tyrosine-protein kinase receptor 2 [sTIE2], PLGF, and interleukin 8 [IL8], as well as lower levels of CSF urokinase-type plasminogen activator [uPA], were associated with worsen cerebrovascular pathologies and neurodegeneration.

DISCUSSION

Our findings indicate that tau pathology may play a critical role in pathological angiogenesis, contributing to cerebrovascular lesions and neurodegeneration in AD.

HIGHLIGHTS

BBB damage and elevated vascular marker CD31 in human AD brains had a stronger correlation with tau pathology than Aβ pathology. CSF pTau181 mediated the effect of CSF Aβ42/40 on CSF sVEGFR1 and sTIE2. Only CSF pTau181 showed positive associations with sVEGFR2, VEGF-C, VEGF-D, PLGF, Angiopoietin2, and Serpin E1. Higher sVEGFR1, sTIE2, PLGF, and IL8, and lower uPA in CSF, were associated with cerebrovascular pathologies and neurodegeneration.

Fabrication and characterization of lactoperoxidase coated the modified graphene oxide-based nanocomposite for medical applications

This study aims to synthesize an innovative (GO-PAA-Cu-LP) nanocomposite through multi-steps for medical applications. First, graphene oxide (GO) was radically anchored with polyacrylic acid (PAA), subsequently, activation through substituting the H-atom of the carboxylic group in PAA with Na-atom. Afterward, Cu-ions are easily loaded over the activated carboxylated groups to act as a satellite in combination with bovine milk lactoperoxidase (LP). The prepared composites were characterized by various techniques, including SEM, TEM, EDX, FTIR, TGA, and XRD analysis, as well as determination of zeta size and potentials for each composite. The experimental results exhibited the ability of LP in the modified form (GO-PAA-Cu-LP) to keep its stability during storage conditions with activity around 73 % of its original reactivity after storage for 9 weeks at 4 °C. The results revealed the selectivity of GO-PAA-Cu-LP against both treated Caco-2 and Huh-7 cells greater than free GO-PAA-Cu composite and free LP. Therefore, these results indicate that the combination of LP with the modified GO-PAA-Cu composite increased its selectivity against all treated cancer cells. These results indicate that the modified GO-PAA-Cu-LP enhanced cell cycle arrest of treated cancer cells in both sub-G1 phase (apoptotic phase) and S phase compared with untreated cells, stimulating apoptotic mechanism.

Enzymatic interlocking aptamer-micelles for enhanced cellular internalization and nucleus-targeted cancer phototherapy

Multifunctional micelles that permit both diagnosis and treatment present enormous advantage and potential for precision medicine. However, the inherent complexities and structural instability of these systems often cause unsatisfactory targeting and therapeutic performances. Herein, by ingenious design of a 2,5-bis(2-thienyl)pyrrole (SNS) modifier to covalently link with AS1411 aptamer and lipid segment, a simple strategy is proposed for one-step enzymatic preparation of interlocked aptamer-micelle (IApM) under bio-friendly conditions. The interlocked poly(SNS) skeleton in IApM can not only stabilize the micelle structure but also enhance near-infrared (NIR) absorption ability, thus further enhancing cellular internalization and photothermal therapy. In addition, the multivalent AS1411 aptamers tethered in the hydrophilic shell can simultaneously increase the specific binding affinity of DNA micelles and induce nucleus-targeted accumulation for DNA damage-triggered apoptosis. This DNA micelle achieves "best of both worlds" with enhanced biostability for cellular internalization and improved NIR photothermal conversion efficiency for nucleus-targeted therapy, which provides a promising formulation strategy for precision cancer treatment.

In Vitro Potentiation of Doxorubicin Cytotoxicity Utilizing Clarithromycin Loaded-PEGylated Liposomes

BACKGROUND

Doxorubicin (DOX) is a potent chemotherapeutic agent for breast cancer, but its effectiveness is often diminished by resistance mechanisms, particularly through p-glycoprotein (P-gp) mediated drug efflux. Clarithromycin (CAM), a macrolide antibiotic, inhibits multiple metabolic pathways including CYP3A and P-gp, potentially countering DOX resistance.

OBJECTIVE

This study aimed to evaluate the potentiation of DOX and its effectiveness against the MCF-7 breast cancer cell line by encapsulating both DOX and CAM in PEGylated liposomes.

METHODS

PEGylated liposomes containing DOX and CAM were prepared using the thin film hydration method. The physicochemical properties of the liposomes, including average particle size, polydispersity index (PDI), and zeta potential, were characterized. Encapsulation efficiencies for CAM and DOX were assessed, and stability of the liposomes was evaluated over 9 days at room temperature. Cell viability was measured using an IC50 assay, and P-gp expression levels were determined by ELISA.

RESULTS

The CAM/DOX-PEGylated liposomes exhibited optimal average particle size (238 ± 26.7 nm), PDI (0.29 ± 0.107), and zeta potential (-20.9 ± 2.17 mV). These liposomes maintained good stability regarding size and charge over 9 days. Encapsulation efficiencies were 81.05% for CAM and 78.13% for DOX. The IC50 value for CAM/DOX-PEGylated liposomes was 0.13 µM, representing a significant reduction compared to the physical mixture of CAM and DOX (0.25 µM) and free DOX (0.21 µM) against MCF-7 cells. ELISA analysis showed a reduction in P-gp expression of approximately 5% with CAM/DOX-PEGylated liposomes compared to 1.61% with free DOX.

CONCLUSION

The results indicate that CAM encapsulated in PEGylated liposomes enhances the effectiveness of DOX against breast cancer cells, likely through the inhibition of p-glycoprotein. This approach may offer a promising strategy to overcome DOX resistance and improve chemotherapy outcomes.

Ultrasound-triggered drug release and cytotoxicity of microbubbles with diverse drug attributes

Ultrasound (US)-triggered cavitation of drug-loaded microbubbles (MBs) represents a promising approach for targeted drug delivery, with substantial benefits attainable through precise control over drug release dosage and form. This study investigates Camptothecin-loaded MBs (CPT-MBs) and Doxorubicin-loaded MBs (DOX-MBs), focusing on how properties such as hydrophilicity, hydrophobicity, and charged functional groups affect their interaction with the lipid surfaces of MBs, thereby influencing the fundamental characteristics and acoustic properties of the drug-loaded MBs. In comparison to DOX-MBs, CPT-MBs showed larger MB size (2.2 ± 0.3 and 1.4 ± 0.1 μm, respectively), a 2-fold increase in drug loading, and an 18 % reduction in leakage after 2 h at 37℃. Under 1 MHz US with a 100 ms pulse repetition interval (PRI), 1000 cycles, 5-minute duration, and 550 kPa acoustic pressure, CPT-MBs undergo inertial cavitation, while DOX-MBs undergo stable cavitation. Drug particles released from these MBs under US-induced cavitation were analyzed using dynamic light scattering, NanoSight, cryo-electron microscopy, and density gradient ultracentrifugation. Results showed that CPT-MBs mainly release free CPT, while DOX-MBs release multilayered DOX-lipid aggregates. The cytotoxicity to C6 cells induced by US-triggered cavitation of these two types of MBs also differed. DOX-lipid aggregates delayed initial uptake, leading to less pronounced short-term (2 h) effects compared to the rapid release of free CPT from CPT-MBs. These findings underscore the need to optimize drug delivery strategies by fine-tuning MB composition and US parameters to control drug release kinetics and achieve the best tumoricidal outcomes.

3D electron microscopy for analyzing nanoparticles in the tumor endothelium

Delivering medical agents to diseased tissues has been challenging, leading researchers to study the in vivo transport process in the body for improving delivery. Many imaging techniques exist for mapping the distribution of medical agent-carrying nanoparticles in tissues, but they cannot capture the three-dimensional context of tissues with single nanoparticle resolution. Here, we developed 3DEM-NPD, a three-dimensional electron microscopy (3D EM) machine learning strategy to image and map single nanoparticle distributions (NPD) in tissues. 3DEM-NPD provides unbiased visualization and quantification of individual nanoparticles within organs. We applied this technique to quantify nanoparticle transport through tumor blood vessel endothelial cells. We measured the cell diameter, surface area, and volume and found that traditional 2D EM cannot accurately measure these features. We used machine learning to locate over 550,000 nanoparticles in less than 3 h with an accuracy of over 82%. The 3DEM-NPD method allowed us to establish a metric to quantify nanoparticle transport at the single nanoparticle level and to quantify the morphological features of ~2,800 vesicles. We find that on average there are only 2.4 nanoparticles per vesicle with a theoretical maximum of 158 nanoparticles per vesicle (~66x increase). These surprising results suggest the need to increase vesicle encapsulation efficiency for improved transport and they provide a benchmark for increasing nanoparticle transport and delivery. This technique may provide unique insights into the interactions between medical agents, drug carriers, emerging materials, and cells at the single-nanoparticle level throughout tissues.

In Vivo Delivery Processes and Development Strategies of Lipid Nanoparticles

Lipid nanoparticles (LNPs) represent an advanced and highly efficient delivery system for RNA molecules, demonstrating exceptional biocompatibility and remarkable delivery efficiency. This is evidenced by the clinical authorization of three LNP formulations: Patisiran, BNT162b2, and mRNA-1273. To further maximize the efficacy of RNA-based therapy, it is imperative to develop more potent LNP delivery systems that can effectively protect inherently unstable and negatively charged RNA molecules from degradation by nucleases, while facilitating their cellular uptake into target cells. Therefore, this review presents feasible strategies commonly employed for the development of efficient LNP delivery systems. The strategies encompass combinatorial chemistry for large-scale synthesis of ionizable lipids, rational design strategy of ionizable lipids, functional molecules-derived lipid molecules, the optimization of LNP formulations, and the adjustment of particle size and charge property of LNPs. Prior to introducing these developing strategies, in vivo delivery processes of LNPs, a crucial determinant influencing the clinical translation of LNP formulations, is described to better understand how to develop LNP delivery systems.

Heat-guided drug delivery via thermally induced crosslinking of polymeric micelles

Targeted drug delivery in response to external stimuli is therapeutically desirable, but long-term drug retention at the target site after stimulation is turned off remains a challenge. Herein, we present a targeted-delivery strategy via irreversible aggregation of drug carriers in response to mild external heating. We constructed two types of polymeric micelles, DBCO-TRM and Az-TRM, having a thermo-responsive polymer shell based on N-isopropylacrylamide (NIPAAm) and incorporating alkyne and azide moieties, respectively. Upon heating at 42 °C, the micelles aggregated through hydrophobic interaction between their dehydrated shells. Further, the azide moieties of Az-TRM become exposed on the surface due to the thermally shrinkage of the shells, thereby enabling crosslinking between the two types of micelles via azide-alkyne click chemistry to form irreversible aggregates. These aggregates were efficiently accumulated at tumor sites in mice by local heating after intravenous administration of a mixture of the micelles, and were well retained after cessation of heating due to their increased size. As proof of concept, we show that delivery of doxorubicin in this heat-guided drug delivery system dramatically improved the anti-tumor effect in a mouse model after a single treatment. Our results suggest that this platform could be an efficient tool for on-demand drug delivery.

Assessing Therapeutic Nanoparticle Accumulation in Tumors Using Nanobubble-Based Contrast-Enhanced Ultrasound Imaging

This study explores the challenges associated with nanoparticle-based drug delivery to the tumor parenchyma, focusing on the widely utilized enhanced permeability and retention effect (EPR). While EPR has been a key strategy, its inconsistent clinical success lacks clear mechanistic understanding and is hindered by limited tools for studying relevant phenomena. This work introduces an approach that employs multiparametric dynamic contrast-enhanced ultrasound (CEUS) with a nanoscale contrast agent for noninvasive, real-time examination of tumor microenvironment characteristics. We demonstrate that CEUS imaging can: (1) evaluate tumor microenvironment features, (2) be used to help predict the distribution of doxorubicin-loaded liposomes in the tumor parenchyma, and (3) be used to predict nanotherapeutic efficacy. CEUS using nanobubbles (NBs) was carried out in two tumor types of high (LS174T) and low (U87) vascular permeability. LS174T tumors consistently showed significantly different time intensity curve (TIC) parameters, including area under the rising curve (AUCR, 2.7×) and time to peak intensity (TTP, 1.9×) compared to U87 tumors. Crucially, a recently developed decorrelation time (DT) parameter specific to NB CEUS dynamics successfully predicted the distribution of doxorubicin-loaded liposomes within the tumor parenchyma (r = 0.86 ± 0.13). AUCR, TTP, and DT were used to correlate imaging findings to nanotherapeutic response with 100% accuracy in SKOV-3 tumors. These findings suggest that NB-CEUS parameters can effectively discern tumor vascular permeability, serving as a biomarker for identifying tumor characteristics and predicting the responsiveness to nanoparticle-based therapies. The observed differences between LS174T and U87 tumors and the accurate prediction of nanotherapeutic efficacy in SKOV-3 tumors indicate the potential utility of this method in predicting treatment efficacy and evaluating EPR in diseases characterized by pathologically permeable vasculature. Ultimately, this research contributes valuable insights into refining drug delivery strategies and assessing the broader applicability of EPR-based approaches.

Fixation alters the physical properties of tumor tissue that regulate nanomedicine transport

To have the desired therapeutic effect, nanomedicines and macromolecular medications must move from the site of injection to the site of action, without having adverse effects. Transvascular transport is a critical step of this navigation, as exemplified by the Enhanced Permeability and Retention (EPR) effect in solid tumors, not found in normal organs. Numerous studies have concluded that passive, diffusion- and convection-based transport predominates over active, cellular mechanisms in this effect. However, recent work using a new approach reevaluated this principle by comparing tumors with or without fixation and concluded the opposite. Here, we address the controversy generated by this new approach by reporting evidence from experimental investigations and computer simulations that separate the contributions of active and passive transport. Our findings indicate that tissue fixation reduces passive transport as well as active transport, indicating the need for new methods to distinguish the relative contributions of passive and active transport.

Comprehensive Review on Bubbles: Synthesis, Modification, Characterization and Biomedical Applications

Accurate detection, treatment, and imaging of diseases are important for effective treatment outcomes in patients. In this regard, bubbles have gained much attention, due to their versatility. Bubbles usually 1 nm to 10 μm in size can be produced and loaded with a variety of lipids, polymers, proteins, and therapeutic and imaging agents. This review details the different production and loading methods for bubbles, for imaging and treatment of diseases/conditions such as cancer, tumor angiogenesis, thrombosis, and inflammation. Bubbles can also be used for perfusion measurements, important for diagnostic and therapeutic decision making in cardiac disease. The different factors important in the stability of bubbles and the different techniques for characterizing their physical and chemical properties are explained, for developing bubbles with advanced therapeutic and imaging features. Hence, the review provides important insights for researchers studying bubbles for biomedical applications.

In vitro evaluation of lipidic nanocarriers for mebendazole delivery to improve anticancer activity

OBJECTIVE

To enhance the anticancer activity of the repurposed drug mebendazole (MBZ) against A549 cell lines by developing nanostructured lipid carriers (NLCs).

SIGNIFICANCE

MBZ, an anthelmintic drug, exhibits anticancer properties primarily through the inhibition of Ran GTPase and mitotic spindle assembly. Enhancing its delivery and efficacy via NLC could provide a novel and effective approach for lung cancer treatment.

METHODS

NLCs were prepared by mixing different ratios of solid lipid (stearic acid) and liquid lipid (oleic acid) with surfactants and emulsifiers. The NLCs were fully characterized to ensure stability, particle size, zeta potential, and encapsulation efficiency (EE%). The stability of the NLCs was monitored over a 3-week period. The anticancer activity of MBZ-NLCs was evaluated using IC50 assays and in vitro scratch assays.

RESULTS

The NLCs exhibited an average particle size of 300 ± 10 nm and a zeta potential of -27 ± 0.5 mV, indicating good stability. EE% significantly improved from 40% in conventional liposome formulations to 90.7% in NLCs. The anticancer activity of MBZ-NLCs was markedly enhanced, with an IC50 of 62 nM compared to 581 nM for free MBZ, representing a 10-fold increase in potency. Additionally, in vitro scratch assays revealed that MBZ-NLCs effectively prevented cell-cell contact, further supporting their potential for improved therapeutic efficacy.

CONCLUSION

MBZ-NLCs exhibit significantly improved stability, EE%, and anticancer activity compared to free MBZ. These promising results suggest that MBZ-NLCs could be a potent therapeutic approach for lung cancer treatment, warranting further in vivo studies and exploration of different administration routes.

High loading and sustained-release system of doxorubicin-carbon dots as nanocarriers for cancer therapeutics

Nanocarriers for drugs have been investigated for decades, yet it is still challenging to achieve sustained release from nanomaterials due to drug loading inefficiency and burst release. In this study, we developed novel functional carbon dots (CDs) and investigated the therapeutic efficacy by studying the loading efficiency and release behavior of the anticancer drug doxorubicin (DOX). CDs were successfully synthesized using a one-step pyrolysis method with varying concentrations of citric acid (CA) and thiourea (TU). Functional groups, morphology, particle size, and zeta potential of synthesized CT-CDs and DOX loaded CT-CDs were investigated by UV-visible, Fluorescence, dynamic light scattering, Zeta Potential measurements, FTIR, and transmission electron microscopy. The zeta potential data revealed DOX loading onto CT-CDs by charge difference, i.e. -24.6 ± 0.44 mV (CT-CDs) and 20.57 ± 0.55 mV (DOX-CT-CDs). DOX was loaded on CDs with a loading efficiency of 88.67 ± 0.36%.In vitrodrug release studies confirmed pH-dependent biphasic drug release, with an initial burst effect and sustained release of DOX was found to be 21.42 ± 0.28% (pH 5), 13.30 ± 0.03% (pH 7.4), and 13.95 ± 0.18% (pH 9) even after 144 h at 37 °C. The CT-CDs were non-toxic and biocompatible with L929 Fibroblasts cells. The cytotoxic effect of DOX-CT-CDs showed a concentration-dependent effect after 48 h with Glioblastoma U251 cells. Flow cytometry was used to examine the cellular uptake of CT-CDs and DOX-CT-CDs in L929 and U251 cells. It was observed that the maximum CT-CDs uptake was around 75% at the end of 24 h. This study showed that the synthesized fluorescent CT-CDs demonstrated a high drug loading capacity, pH-dependent sustained release of DOX, and high cellular uptake by mammalian cells. We believe this work provides practical and biocompatible CDs for chemotherapeutic drug delivery that can be applied to other drugs for certain therapeutic aims.

Investigation of Ultrasound Mediated Extravasation of a Model Drug by Perfluorobutane Nanodroplets

OBJECTIVE

Perfluorocarbon nanodroplets (NDs) have been widely investigated as both diagnostic and therapeutic agents. There remains, however, a challenge in generating NDs that do not vaporize spontaneously but can be activated at ultrasound pressures that do not produce unwanted bioeffects. In previous work, it has been shown that phospholipid-coated perfluorobutane (PFB) NDs can potentially overcome this challenge. The aim of this study was to investigate whether these NDs can promote drug delivery.

METHODS

A combination of high-speed optical imaging and passive cavitation detection was used to study the acoustic properties of the PFB-NDs in a tissue mimicking phantom. PFB-NDs were exposed to ultrasound at frequencies from 0.5 to 1.5 MHz and peak negative pressures from 0.5 to 3.5 MPa. In addition, the penetration depth of two model drugs (Nile Red and 200 nm diameter fluorescent polymer spheres) into the phantom was measured.

RESULTS

PFB NDs were found to be stable in aqueous suspension at both 4°C and 37°C; their size remaining unchanged at 215 ± 11 nm over 24 h. Penetration of both model drugs in the phantom was found to increase with increasing ultrasound peak negative pressure and decreasing frequency and was found to be positively correlated with the energy of acoustic emissions. Extravasation depths >1 mm were observed at 0.5 MHz with pressures <1 MPa.

CONCLUSION

The results of the study thus suggest that PFB NDs can be used both as drug carriers and as nuclei for cavitation to enhance drug delivery without the need for high intensity ultrasound.

Deformable nanocarriers for enhanced drug delivery and cancer therapy

Recently, the field of nanomedicine has witnessed substantial advancements in the development of nanocarriers for targeted drug delivery, emerges as promising platforms to enhance therapeutic efficacy and minimize adverse effects associated with conventional chemotherapy. Notably, deformable nanocarriers have garnered considerable attention due to their unique capabilities of size changeable, tumor-specific aggregation, stimuli-triggered disintegration, and morphological transformations. These deformable nanocarriers present significant opportunities for revolutionizing drug delivery strategies, by responding to specific stimuli or environmental cues, enabling achieved various functions at the tumor site, including size-shrinkage nanocarriers enhance drug penetration, aggregative nanocarriers enhance retention effect, disintegrating nanocarriers enable controlled drug release, and shape-changing nanocarriers improve cellular uptake, allowing for personalized treatment approaches and combination therapies. This review provides an overview of recent developments and applications of deformable nanocarriers for enhancing tumor therapy, underscores the diverse design strategies employed to create deformable nanocarriers and elucidates their remarkable potential in targeted tumor therapy.

The radial dynamics and acoustic emissions of phase-shift droplets are impacted by mechanical properties of tissue-mimicking hydrogels

Acoustic droplet vaporization (ADV) offers a dynamic approach for generating bubbles on demand, presenting new possibilities in biomedical applications. Although ADV has been investigated in various biomedical applications, its potential in tissue characterization remains unexplored. Here, we investigated the effects of surrounding media on the radial dynamics and acoustic emissions of ADV bubbles using theoretical and experimental methodologies. For theoretical studies, bubble dynamics were combined with the Kelvin-Voigt material constitutive model, accounting for viscoelasticity of the media. The radial dynamics and acoustic emissions of the ADV-bubbles were recorded via ultra-high-speed microscopy and passive cavitation detection, respectively. Perfluoropentane phase-shift droplets were embedded in tissue-mimicking hydrogels of varying fibrin concentrations, representing different elastic moduli. Radial dynamics and the acoustic emissions, both temporal and spectral, of the ADV-bubbles depended significantly on fibrin elastic modulus. For example, an increase in fibrin elastic modulus from ≈0.2 kPa to ≈6 kPa reduced the maximum expansion radius of the ADV-bubbles by 50%. A similar increase in the elastic modulus significantly impacted both linear (e.g., fundamental) and nonlinear (e.g., subharmonic) acoustic responses of the ADV-bubbles, by up to 10 dB. The sensitivity of ADV to the surrounding media was dependent on acoustic parameters such as driving pressure and the droplets concentration. Further analysis of the acoustic emissions revealed distinct ADV signal characteristics, which were significantly influenced by the surrounding media.

The Influence of Size on the Intracranial Distribution of Biomedical Nanoparticles Administered by Convection-enhanced Delivery in Minipigs

Because of the blood-brain barrier (BBB), successful drug delivery to the brain has long been a key objective for the medical community, calling for pioneering technologies to overcome this challenge. Convection-enhanced delivery (CED), a form of direct intraparenchymal microinfusion, shows promise but requires optimal infusate design and real-time distribution monitoring. The size of the infused substances appears to be especially critical, with current knowledge being limited. Herein, we examined the intracranial administration of polyethylene glycol (PEG)-coated nanoparticles (NPs) of various sizes using CED in groups of healthy minipigs (n = 3). We employed stealth liposomes (LIPs, 130 nm) and two gold nanoparticle designs (AuNPs) of different diameters (8 and 40 nm). All were labeled with copper-64 for quantitative and real-time monitoring of the infusion via positron emission tomography (PET). NPs were infused via two catheters inserted bilaterally in the putaminal regions of the animals. Our results suggest CED with NPs holds promise for precise brain drug delivery, with larger LIPs exhibiting superior distribution volumes and intracranial retention over smaller AuNPs. PET imaging alongside CED enabled dynamic visualization of the process, target coverage, timely detection of suboptimal infusion, and quantification of distribution volumes and concentration gradients. These findings may augment the therapeutic efficacy of the delivery procedure while mitigating unwarranted side effects associated with nonvisually monitored delivery approaches. This is of vital importance, especially for chronic intermittent infusions through implanted catheters, as this information enables informed decisions for modulating targeted infusion volumes on a catheter-by-catheter, patient-by-patient basis.

Boron Neutron Capture Therapy Enhanced by Boronate Ester Polymer Micelles: Synthesis, Stability, and Tumor Inhibition Studies

Boron neutron capture therapy (BNCT) targets invasive, radioresistant cancers but requires a selective and high B-10 loading boron drug. This manuscript investigates boron-rich poly(ethylene glycol)-block-(poly(4-vinylphenyl boronate ester)) polymer micelles synthesized via atom transfer radical polymerization for their potential application in BNCT. Transmission electron microscopy (TEM) revealed spherical micelles with a uniform size of 43 ± 10 nm, ideal for drug delivery. Additionally, probe sonication proved effective in maintaining the micelles' size and morphology postlyophilization and reconstitution. In vitro studies with B16-F10 melanoma cells demonstrated a 38-fold increase in boron accumulation compared to the borophenylalanine drug for BNCT. In vivo studies in a B16-F10 tumor-bearing mouse model confirmed enhanced tumor selectivity and accumulation, with a tumor-to-blood (T/B) ratio of 2.5, surpassing BPA's T/B ratio of 1.8. As a result, mice treated with these micelles experienced a significant delay in tumor growth, highlighting their potential for BNCT and warranting further research.

Nanoplatform-Based In Vivo Gene Delivery Systems for Cancer Therapy

Gene therapy uses modern molecular biology methods to repair disease-causing genes. As a burgeoning therapeutic, it has been widely applied for cancer therapy. Since 1989, there have been numerous clinical gene therapy cases worldwide. However, a few are successful. The main challenge of clinical gene therapy is the lack of efficient and safe vectors. Although viral vectors show high transfection efficiency, their application is still limited by immune rejection and packaging capacity. Therefore, the development of non-viral vectors is overwhelming. Nanoplatform-based non-viral vectors become a hotspot in gene therapy. The reasons are mainly as follows. 1) Non-viral vectors can be engineered to be uptaken by specific types of cells or tissues, providing effective targeting capability. 2) Non-viral vectors can protect goods that need to be delivered from degradation. 3) Nanoparticles can transport large-sized cargo such as CRISPR/Cas9 plasmids and nucleoprotein complexes. 4) Nanoparticles are highly biosafe, and they are not mutagenic in themselves compared to viral vectors. 5) Nanoparticles are easy to scale preparation, which is conducive to clinical conversion and application. Here, an overview of the categories of nanoplatform-based non-viral gene vectors, the limitations on their development, and their applications in cancer therapy.

Microwave-Responsive Metal-Organic Frameworks (MOFs) for Enhanced In Vitro Controlled Release of Doxorubicin

Metal-organic frameworks (MOFs) are excellent candidates for a range of applications because of their numerous advantages, such as high surface area, porosity, and thermal and chemical stability. In this study, microwave (MW) irradiation is used as a novel stimulus in vitro controlled release of Doxorubicin (DOX) from two MOFs, namely Fe-BTC and MIL-53(Al), to enhance drug delivery in cancer therapy. DOX was encapsulated into Fe-BTC and MIL-53(Al) with drug-loading efficiencies of up to 67% for Fe-BTC and 40% for MIL-53(Al). Several characterization tests, including XRD, FTIR, TGA, BET, FE-SEM, and EDX, confirmed both MOF samples' drug-loading and -release mechanisms. Fe-BTC exhibited a substantial improvement in drug-release efficiency (54%) when exposed to microwave irradiation at pH 7.4 for 50 min, whereas 11% was achieved without the external modality. A similar result was observed at pH 5.3; however, in both cases, the release efficiencies were substantially higher with microwave exposure (40%) than without (6%). In contrast, MIL-53(Al) exhibited greater sensitivity to pH, displaying a higher release rate (66%) after 38 min at pH 5.3 compared to 55% after 50 min at pH 7.4 when subjected to microwave irradiation. These results highlight the potential of both MOFs as highly heat-responsive to thermal stimuli. The results of the MTT assay demonstrated the cell viability across different concentrations of the MOFs after two days of incubation. This suggests that MOFs hold promise as potential candidates for tumor targeting. Additionally, the fact that the cells maintained their viability at different durations of microwave exposure confirms that the latter is a safe modality for triggering drug release from MOFs.

Advances of ultrasound in tumor immunotherapy

Immunotherapy has become a revolutionary method for treating tumors, offering new hope to cancer patients worldwide. Immunotherapy strategies such as checkpoint inhibitors, chimeric antigen receptor T-cell (CAR-T) therapy, and cancer vaccines have shown significant potential in clinical trials. Despite the promising results, there are still limitations that impede the overall effectiveness of immunotherapy; the response to immunotherapy is uneven, the response rate of patients is still low, and systemic immune toxicity accompanied with tumor cell immune evasion is common. Ultrasound technology has evolved rapidly in recent years and has become a significant player in tumor immunotherapy. The introductions of high intensity focused ultrasound and ultrasound-stimulated microbubbles have opened doors for new therapeutic strategies in the fight against tumor. This paper explores the revolutionary advancements of ultrasound combined with immunotherapy in this particular field.

Polymeric nanotheranostics for solid tumor management: Recent developments and global regulatory landscape

Polymeric nanotheranostics have emerged as promising vehicles for diagnosis‐cum‐targeted therapy in solid tumors, offering precise delivery of therapeutic agents at the site of solid tumors and minimizing systemic side effects. This article summarizes the latest developments in using polymeric nanoparticles for specific treatment strategies in solid tumors. It explores the various methods these nanoparticles utilize for targeted medication delivery. This includes passive targeting through the amplified permeability and retention effect, active targeting via interactions between ligands and receptors, and stimuli‐responsive release mechanisms such as pH, temperature, and enzymatic triggers. Furthermore, we highlight recent developments in stimuli‐responsive polymeric nanoparticles, which enable controlled drug release in response to specific cues in the tumor microenvironment, thus enhancing therapeutic efficacy. Also, we focus on the theranostic polymeric nanoparticles, which are used for diagnosing and treating solid tumors. We discuss critical regulatory considerations and the regulatory bodies of different countries that regulate nanomedicines' safety, efficacy, quality, and manufacturing processes. Overall, this review provides insights into the latest innovations in polymeric nanoparticles for targeted therapy in solid tumors, elucidating their mechanisms of action, stimuli‐responsive properties, and regulatory pathways, which collectively contribute to developing effective and safe nanomedicines for cancer treatment.

Semiconducting polymer dots for multifunctional integrated nanomedicine carriers

The expansion applications of semiconducting polymer dots (Pdots) among optical nanomaterial field have long posed a challenge for researchers, promoting their intelligent application in multifunctional nano-imaging systems and integrated nanomedicine carriers for diagnosis and treatment. Despite notable progress, several inadequacies still persist in the field of Pdots, including the development of simplified near-infrared (NIR) optical nanoprobes, elucidation of their inherent biological behavior, and integration of information processing and nanotechnology into biomedical applications. This review aims to comprehensively elucidate the current status of Pdots as a classical nanophotonic material by discussing its advantages and limitations in terms of biocompatibility, adaptability to microenvironments in vivo, etc. Multifunctional integration and surface chemistry play crucial roles in realizing the intelligent application of Pdots. Information visualization based on their optical and physicochemical properties is pivotal for achieving detection, sensing, and labeling probes. Therefore, we have refined the underlying mechanisms and constructed multiple comprehensive original mechanism summaries to establish a benchmark. Additionally, we have explored the cross-linking interactions between Pdots and nanomedicine, potential yet complete biological metabolic pathways, future research directions, and innovative solutions for integrating diagnosis and treatment strategies. This review presents the possible expectations and valuable insights for advancing Pdots, specifically from chemical, medical, and photophysical practitioners' standpoints.

Nucleic acid-based drugs for patients with solid tumours

The treatment of patients with advanced-stage solid tumours typically involves a multimodality approach (including surgery, chemotherapy, radiotherapy, targeted therapy and/or immunotherapy), which is often ultimately ineffective. Nucleic acid-based drugs, either as monotherapies or in combination with standard-of-care therapies, are rapidly emerging as novel treatments capable of generating responses in otherwise refractory tumours. These therapies include those using viral vectors (also referred to as gene therapies), several of which have now been approved by regulatory agencies, and nanoparticles containing mRNAs and a range of other nucleotides. In this Review, we describe the development and clinical activity of viral and non-viral nucleic acid-based treatments, including their mechanisms of action, tolerability and available efficacy data from patients with solid tumours. We also describe the effects of the tumour microenvironment on drug delivery for both systemically administered and locally administered agents. Finally, we discuss important trends resulting from ongoing clinical trials and preclinical testing, and manufacturing and/or stability considerations that are expected to underpin the next generation of nucleic acid agents for patients with solid tumours.

Layered rare-earth hydroxides as multi-modal medical imaging probes: particle size optimisation and compositional exploration

Recently, layered rare-earth hydroxides (LRHs) have received growing attention in the field of theranostics. We have previously reported the hydrothermal synthesis of layered terbium hydroxide (LTbH), which exhibited high biocompatibility, reversible uptake of a range of model drugs, and release-sensitive phosphorescence. Despite these favourable properties, LTbH particles produced by the reported method suffered from poor size-uniformity (670 ± 564 nm), and are thus not suitable for therapeutic applications. To ameliorate this issue, we first derive an optimised hydrothermal synthesis method to generate LTbH particles with a high degree of homogeneity and reproducibility, within a size range appropriate for in vivo applications (152 ± 59 nm, n = 6). Subsequently, we apply this optimised method to synthesise a selected range of LRH materials (R = Pr, Nd, Gd, Dy, Er, Yb), four of which produced particles with an average size under 200 nm (Pr, Nd, Gd, and Dy) without the need for further optimisation. Finally, we incorporate Gd and Tb into LRHs in varying molar ratios (1 : 3, 1 : 1, and 3 : 1) and assess the combined magnetic relaxivity and phosphorescence properties of the resultant LRH materials. The lead formulation, LGd1.41Tb0.59H, was demonstrated to significantly shorten the T2 relaxation time of water (r2 = 52.06 mM-1 s-1), in addition to exhibiting a strong phosphorescence signal (over twice that of the other LRH formulations, including previously reported LTbH), therefore holding great promise as a potential multi-modal medical imaging probe.

The dawn of a new Era: mRNA vaccines in colorectal cancer immunotherapy

Colorectal cancer (CRC) is a typical cancer that accounts for 10% of all new cancer cases annually and nearly 10% of all cancer deaths. Despite significant progress in current classical interventions for CRC, these traditional strategies could be invasive and with numerous adverse effects. The poor prognosis of CRC patients highlights the evident and pressing need for more efficient and targeted treatment. Novel strategies regarding mRNA vaccines for anti-tumor therapy have also been well-developed since the successful application for the prevention of COVID-19. mRNA vaccine technology won the 2023 Nobel Prize in Physiology or Medicine, signaling a new direction in human anti-cancer treatment: mRNA medicine. As a promising new immunotherapy in CRC and other multiple cancer treatments, the mRNA vaccine has higher specificity, better efficacy, and fewer side effects than traditional strategies. The present review outlines the basics of mRNA vaccines and their advantages over other vaccines and informs an available strategy for developing efficient mRNA vaccines for CRC precise treatment. In the future, more exploration of mRNA vaccines for CRC shall be attached, fostering innovation to address existing limitations.

Ultrasound-mediated drug-free theranostics for treatment of prostate cancer

Lipid-shelled nanobubbles (NBs) can be visualized and activated using noninvasive ultrasound (US) stimulation, leading to significant bioeffects. Prior work demonstrates that active targeting of NBs to prostate-specific membrane antigen (PSMA) overexpressed in prostate cancer (PCa) results in enhanced cellular internalization and prolongs NB retention with persistent, cancer-cell specific acoustic activity. In this work, we hypothesized that tumor-accumulated PSMA-NBs combined with low frequency unfocused therapeutic US (TUS) will lead to selective damage and induce a specific therapeutic effect in PSMA-expressing tumors compared to PSMA-negative tumors. We observed that the internalized NBs and cellular compartments were disrupted after the PSMA-NB + TUS (targeted NB therapy or TNT) application, yet treated cells remained intact and viable. In vivo, PSMA-expressing tumors in mice receiving TNT treatment demonstrated a significantly greater extent of apoptosis (78.4 ± 9.3 %, p < 0.01) compared to controls. TNT treatment significantly inhibited the PSMA expressing tumor growth and increased median survival time by 103 %, p < 0.001). A significant reduction in tumor progression compared to untreated control was also seen in an orthotopic rabbit PCa model. Results demonstrate that cavitation of PSMA-NBs internalized via receptor-mediated endocytosis into target PCa cells using unfocused ultrasound results in significant, tumor-specific bioeffects. The effects, while not lethal to PSMA-expressing cancer cells in vitro, result in significant in vivo reduction in tumor progression in two models of PCa. While the mechanism of action of these effects is yet unclear, it is likely related to a locally-induced immune response, opening the door to future investigations in this area.

Nanoscale strides: exploring innovative therapies for breast cancer treatment

Breast cancer (BC) is a predominant malignancy in women that constitutes approximately 30% of all cancer cases and has a mortality rate of 14% in recent years. The prevailing therapies include surgery, chemotherapy, and radiotherapy, each with its own limitations and challenges. Despite oral or intravenous administration, there are numerous barriers to accessing anti-BC agents before they reach the tumor site, including physical, physiological, and biophysical barriers. The complexity of BC pathogenesis, attributed to a combination of endogenous, chronic, intrinsic, extrinsic and genetic factors, further complicates its management. Due to the limitations of existing cancer treatment approaches, there is a need to explore novel, efficacious solutions. Nanodrug delivery has emerged as a promising avenue in cancer chemotherapy, aiming to enhance drug bioavailability while mitigating adverse effects. In contrast to conventional chemotherapy, cancer nanotechnology leverages improved permeability to achieve comprehensive disruption of cancer cells. This approach also presented superior pharmacokinetic profiles. The application of nanotechnology in cancer therapeutics includes nanotechnological tools, but a comprehensive review cannot cover all facets. Thus, this review concentrates specifically on BC treatment. The focus lies in the successful implementation of systematic nanotherapeutic strategies, demonstrating their superiority over conventional methods in delivering anti-BC agents. Nanotechnology-driven drug delivery holds immense potential in treating BC. By surmounting multiple barriers and capitalizing on improved permeability, nanodrug delivery has demonstrated enhanced efficacy and reduced adverse effects compared to conventional therapies. This review highlights the significance of systematic nanotherapy approaches, emphasizing the evolving landscape of BC management.

Investigating the synergistic effects of immunotherapy and normalization treatment in modulating tumor microenvironment and enhancing treatment efficacy

We developed a comprehensive mathematical model of cancer immunotherapy that takes into account: i) Immune checkpoint blockers (ICBs) and the interactions between cancer cells and the immune system, ii) characteristics of the tumor microenvironment, such as the tumor hydraulic conductivity, interstitial fluid pressure, and vascular permeability, iii) spatial and temporal variations of the modeled components within the tumor and the surrounding host tissue, iv) the transport of modeled components through the vasculature and between the tumor-host tissue with convection and diffusion, and v) modeling of the tumor draining lymph nodes were the antigen presentation and the development of cytotoxic immune cells take place. Our model successfully reproduced experimental data from various murine tumor types and predicted immune system profiling, which is challenging to achieve experimentally. It showed that combination of ICB therapy and normalization treatments, that aim to improve tumor perfusion, decreases interstitial fluid pressure and increases the concentration of both innate and adaptive immune cells at the tumor center rather than the periphery. Furthermore, using the model, we investigated the impact of modeled components on treatment outcomes. The analysis found that the number of functional vessels inside the tumor region and the ICB dose administered have the largest impact on treatment outcomes.

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.

Selective inhibition of partial EMT-induced tumour cell growth by cerium valence states of extracellular ceria nanoparticles for anticancer treatment

Targeting specific tumour cells and their microenvironments is essential for enhancing the efficacy of chemotherapy and reducing its side effects. A partial epithelial-to-mesenchymal transition state (pEMT, with a hybrid epithelial/mesenchymal phenotype) in tumour cells is an attractive targeting for anticancer treatment because it potentially provides maximal stemness and metastasis relevant to malignant cancer stem cell-like features. However, treatment strategies to target pEMT in tumour cells remain a challenge. This study demonstrates that extracellular cerium oxide nanoparticles (CNPs) selectively inhibit the growth of pEMT-induced tumour cells, without affecting full epithelial tumour cells. Herein, highly concentrated Ce3+ and Ce4+ ions are formed on CNP-layered poly-L-lactic acid surfaces. Cell cultures of pEMT-induced and uninduced lung cancer cell lines on the CNP-layered substrates allow the effect of extracellular CNPs on tumour cell growth to be investigated. The extracellular CNPs with dominant Ce3+ and Ce4+ ions were able to trap pEMT-induced tumour cells in a growth-arrested quiescent/dormant or cytostatic state without generating redox-related reactive oxygen species (ROS), i.e. non-redox mechanisms. The dominant Ce3+ state provided highly efficient growth inhibition of the pEMT-induced tumour cells. In contrast, the dominant Ce4+ state showed highly selective and appropriate growth regulation of normal and tumour cells, including a mesenchymal phenotype. Furthermore, Ce4+-CNPs readily adsorbed serum-derived fibronectin and laminin. Cerium valence-specific proteins adsorbed on CNPs may influence receptor-mediated cell-CNP interactions, leading to tumour cell growth inhibition. These findings provide new perspectives for pEMT-targeting anticancer treatments based on the unique biointerface of extracellular CNPs with different Ce valence states.

The interaction between particles and vascular endothelium in blood flow

Particle-based drug delivery systems have shown promising application potential to treat human diseases; however, an incomplete understanding of their interactions with vascular endothelium in blood flow prevents their inclusion into mainstream clinical applications. The flow performance of nano/micro-sized particles in the blood are disturbed by many external/internal factors, including blood constituents, particle properties, and endothelium bioactivities, affecting the fate of particles in vivo and therapeutic effects for diseases. This review highlights how the blood constituents, hemodynamic environment and particle properties influence the interactions and particle activities in vivo. Moreover, we briefly summarized the structure and functions of endothelium and simulated devices for studying particle performance under blood flow conditions. Finally, based on particle-endothelium interactions, we propose future opportunities for novel therapeutic strategies and provide solutions to challenges in particle delivery systems for accelerating their clinical translation. This review helps provoke an increasing in-depth understanding of particle-endothelium interactions and inspires more strategies that may benefit the development of particle medicine.

Effect of biophysical properties of tumor extracellular matrix on intratumoral fate of nanoparticles: Implications on the design of nanomedicine

Nanomedicine has a profound impact on various research domains including drug delivery, diagnostics, theranostics, and regenerative medicine. Nevertheless, the clinical translation of nanomedicines for solid cancer remains limited due to the abundant physiological and pathological barriers in tumor that hinder the intratumoral penetration and distribution of these nanomedicines. In this article, we review the dynamic remodeling of tumor extracellular matrix during the tumor progression, discuss the impact of biophysical obstacles within tumors on the penetration and distribution of nanomedicines within the solid tumor and collect innovative approaches to surmount these obstacles for improving the penetration and accumulation of nanomedicines in tumor. Furthermore, we dissect the challenges and opportunities of the respective approaches, and propose potential avenues for future investigations. The purpose of this review is to provide a perspective guideline on how to effectively enhance the penetration of nanomedicines within tumors using promising methods.

Using imaging modalities to predict nanoparticle distribution and treatment efficacy in solid tumors: The growing role of ultrasound

Nanomedicine in oncology has not had the success in clinical impact that was anticipated in the early stages of the field's development. Ideally, nanomedicines selectively accumulate in tumor tissue and reduce systemic side effects compared to traditional chemotherapeutics. However, this has been more successful in preclinical animal models than in humans. The causes of this failure to translate may be related to the intra- and inter-patient heterogeneity of the tumor microenvironment. Predicting whether a patient will respond positively to treatment prior to its initiation, through evaluation of characteristics like nanoparticle extravasation and retention potential in the tumor, may be a way to improve nanomedicine success rate. While there are many potential strategies to accomplish this, prediction and patient stratification via noninvasive medical imaging may be the most efficient and specific strategy. There have been some preclinical and clinical advances in this area using MRI, CT, PET, and other modalities. An alternative approach that has not been studied as extensively is biomedical ultrasound, including techniques such as multiparametric contrast-enhanced ultrasound (mpCEUS), doppler, elastography, and super-resolution processing. Ultrasound is safe, inexpensive, noninvasive, and capable of imaging the entire tumor with high temporal and spatial resolution. In this work, we summarize the in vivo imaging tools that have been used to predict nanoparticle distribution and treatment efficacy in oncology. We emphasize ultrasound imaging and the recent developments in the field concerning CEUS. The successful implementation of an imaging strategy for prediction of nanoparticle accumulation in tumors could lead to increased clinical translation of nanomedicines, and subsequently, improved patient outcomes. This article is categorized under: Diagnostic Tools In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery Emerging Technologies.

Microfluidic synthesis of lipid-based nanoparticles for drug delivery: recent advances and opportunities

Microfluidic technologies are revolutionizing the synthesis of nanoscale lipid particles and enabling new opportunities for the production of lipid-based nanomedicines. By harnessing the benefits of microfluidics for controlling diffusive and advective transport within microfabricated flow cells, microfluidic platforms enable unique capabilities for lipid nanoparticle synthesis with precise and tunable control over nanoparticle properties. Here we present an assessment of the current state of microfluidic technologies for lipid-based nanoparticle and nanomedicine production. Microfluidic techniques are discussed in the context of conventional production methods, with an emphasis on the capabilities of microfluidic systems for controlling nanoparticle size and size distribution. Challenges and opportunities associated with the scaling of manufacturing throughput are discussed, together with an overview of emerging microfluidic methods for lipid nanomedicine post-processing. The impact of additive manufacturing on current and future microfluidic platforms is also considered.

Nanotechnology-based delivery systems to overcome drug resistance in cancer

Cancer nanomedicine is defined as the application of nanotechnology and nanomaterials for the formulation of cancer therapeutics that can overcome the impediments and restrictions of traditional chemotherapeutics. Multidrug resistance (MDR) in cancer cells can be defined as a decrease or abrogation in the efficacy of anticancer drugs that have different molecular structures and mechanisms of action and is one of the primary causes of therapeutic failure. There have been successes in the development of cancer nanomedicine to overcome MDR; however, relatively few of these formulations have been approved by the United States Food and Drug Administration for the treatment of cancer. This is primarily due to the paucity of knowledge about nanotechnology and the fundamental biology of cancer cells. Here, we discuss the advances, types of nanomedicines, and the challenges regarding the translation of in vitro to in vivo results and their relevance to effective therapies.

A Tunable Glycosaminoglycan-Peptide Nanoparticle Platform for the Protection of Therapeutic Peptides

The popularity of Glycosaminoglycans (GAGs) in drug delivery systems has grown as their innate ability to sequester and release charged molecules makes them adept in the controlled release of therapeutics. However, peptide therapeutics have been relegated to synthetic, polymeric systems, despite their high specificity and efficacy as therapeutics because they are rapidly degraded in vivo when not encapsulated. We present a GAG-based nanoparticle system for the easy encapsulation of cationic peptides, which offers control over particle diameter, peptide release behavior, and swelling behavior, as well as protection from proteolytic degradation, using a singular, organic polymer and no covalent linkages. These nanoparticles can encapsulate cargo with a particle diameter range spanning 130-220 nm and can be tuned to release cargo over a pH range of 4.5 to neutral through the modulation of the degree of sulfation and the molecular weight of the GAG. This particle system also confers better in vitro performance than the unencapsulated peptide via protection from enzymatic degradation. This method provides a facile way to protect therapeutic peptides via the inclusion of the presented binding sequence and can likely be expanded to larger, more diverse cargo as well, abrogating the complexity of previously demonstrated systems while offering broader tunability.

Advancing cancer treatment: in vivo delivery of therapeutic small noncoding RNAs

In recent years, small non-coding RNAs (ncRNAs) have emerged as a new player in the realm of cancer therapeutics. Their unique capacity to directly modulate genetic networks and target oncogenes positions them as valuable complements to existing small-molecule drugs. Concurrently, the advancement of small ncRNA-based therapeutics has rekindled the pursuit of efficacious in vivo delivery strategies. In this review, we provide an overview of the most current clinical and preclinical studies in the field of small ncRNA-based cancer therapeutics. Furthermore, we shed light on the pivotal challenges hindering the successful translation of these promising therapies into clinical practice, with a specific focus on delivery methods, aiming to stimulate innovative approaches to address this foundational aspect of cancer treatment.

Selective homing of brain-derived reconstituted lipid nanoparticles to cerebral ischemic area enables improved ischemic stroke treatment

Lipid nanoparticles (LNPs) hold great promise as carriers for developing drug delivery systems (DDSs) aimed at managing ischemic stroke (IS). Previous research has highlighted the vital role played by the lipid composition and biophysical characteristics of LNPs, influencing their interactions with cells and tissues. This understanding presents an opportunity to engineer LNPs tailored specifically for enhanced IS treatment. We previously introduced the innovative concept of reconstituted lipid nanoparticles (rLNPs), which not only retain the advantages of conventional LNPs but also incorporate lipids from the originating cell or tissue. Brain-derived rLNPs (B-rLNPs) exhibit significantly superior accumulation within the cerebral ischemic region when compared to liver-derived rLNPs (L-rLNPs). The homing effect of B-rLNPs was then employed to construct 3-n-butylphthalide (NBP) loaded DDS (B-rLNPs/NBP) for the treatment of IS. Our results demonstrated that compared with free NBP, B-rLNPs/NBP can significantly reduce infarct volume, neurological deficits, blood-brain barrier (BBB) leakage rate, brain water content, neutrophil infiltration, alleviate pathological structures, and improve the motor function in MCAO/R model. We also proved that B-rLNPs/NBP showed further reinforced protective effects on the same model than free NBP through the regulation of TLR4/MyD88/NF-κB (anti-inflammation) and Bax/Bcl-2 (anti-apoptosis) pathways. This study offers a promising tool towards improved IS treatment.

Nanomaterials for Ultrasound Imaging- Guided Sonodynamic Therapy

Ultrasound examination is becoming the most popular medical imaging modality because of its low cost and high safety profile. Ultrasound contrast agents enhance the scattering of sound waves, which can improve the clarity and resolution of images. Nanoparticle Ultrasound contrast agents have the characteristics of a large specific surface area and a modifiable surface, which can increase drug loading capacity, prolong circulation time, and enable drug enrichment in specific organs or tissues. This leads to improved therapeutic effects and reducing toxic and side effects. Compared with traditional ultrasound contrast agents, Nano-ultrasound contrast agents overcome the limitation of imaging solely within blood vessels and facilitate imaging within tumor tissues, thereby extending the duration of enhanced imaging. Sonodynamic therapy is an emerging treatment method that has been developed rapidly in recent years, which has the advantages of noninvasive, high spatial and temporal resolution, and low toxicity and side effects. Sonodynamic therapy utilizes a sonosensitizer that, when excited by ultrasound at the tumor site, produces toxic reactive oxygen species, inducing apoptosis or necrosis in tumor cells. Ultrasound-guided sonodynamic therapy allows for real-time observation of lesions, is convenient and flexible, and is free of radiation exposure. With the use of nanomaterials as carriers, ultrasound-guided sonodynamic therapy has made significant strides. This study categorizes and summarizes the current research on acoustic sensitizer carrier materials, including carbon-based, silicon-based, peptide-based, iron-based, metal-organic frameworks, polymers, and liposomes. It concludes by highlighting the current challenges in the integration of ultrasound imaging with sonodynamic therapy and suggests future directions for clinical application development.

Layer-by-Layer Polymer Functionalization Improves Nanoparticle Penetration and Glioblastoma Targeting in the Brain

Glioblastoma is characterized by diffuse infiltration into surrounding healthy brain tissues, which makes it challenging to treat. Complete surgical resection is often impossible, and systemically delivered drugs cannot achieve adequate tumor exposure to prevent local recurrence. Convection-enhanced delivery (CED) offers a method for administering therapeutics directly into brain tumor tissue, but its impact has been limited by rapid clearance and off-target cellular uptake. Nanoparticle (NP) encapsulation presents a promising strategy for extending the retention time of locally delivered therapies while specifically targeting glioblastoma cells. However, the brain's extracellular structure poses challenges for NP distribution due to its narrow, tortuous pores and a harsh ionic environment. In this study, we investigated the impact of NP surface chemistry using layer-by-layer (LbL) assembly to design drug carriers for broad spatial distribution in brain tissue and specific glioblastoma cell targeting. We found that poly-l-glutamate and hyaluronate were effective surface chemistries for targeting glioblastoma cells in vitro. Coadsorbing either polymer with a small fraction of PEGylated polyelectrolytes improved the colloidal stability without sacrificing cancer cell selectivity. Following CED in vivo, gadolinium-functionalized LbL NPs enabled MRI visualization and exhibited a distribution volume up to three times larger than liposomes and doubled the retention half-time up to 13.5 days. Flow cytometric analysis of CED-treated murine orthotopic brain tumors indicated greater cancer cell uptake and reduced healthy cell uptake for LbL NPs compared to nonfunctionalized liposomes. The distinct cellular outcomes for different colayered LbL NPs provide opportunities to tailor this modular delivery system for various therapeutic applications.