Molecular imaging in cancer

Cathepsin B-Activated Fluorescent and Photoacoustic Imaging of Tumor

Early diagnosis is crucial to the treatment of cancer. Cathepsin B (CTB) plays an important role in numerous cancers, which is a promising biomarker for early diagnosis of cancer. It is necessary to exploit new probes for visualization of CTB in vivo. Fluorescent/photoacoustic (FL/PA) imaging is a powerful tool for in vivo study which possesses both excellent sensitivity and spatial resolution. To our knowledge, there has been no FL/PA probe to image CTB in vitro or in vivo. Therefore, we developed two CTB-activated FL/PA probes HCy-Cit-Val and HCy-Gly-Leu-Phe-Gly, which could successfully monitor CTB activity in vivo. Both two probes had excellent sensitivity and selectivity in vitro. Cell imaging showed that HCy-Cit-Val or HCy-Gly-Leu-Phe-Gly could image endogenous CTB in lysosome with 6.8-fold or 5.1-fold enhancement of the FL signal and 5.8-fold or 3.4-fold enhancement of the PA signal compared to their inhibitor contrast groups. Tumor imaging in vivo further confirmed the good applicability of these two probes to monitor CTB activity with high sensitivity and spatial resolution. Moreover, the property of HCy-Cit-Val is superior to HCy-Gly-Leu-Phe-Gly due to the higher catalytic efficiency of CTB toward HCy-Cit-Val than HCy-Gly-Leu-Phe-Gly. We envision that our FL/PA probe HCy-Cit-Val will be suitable for clinical early diagnosis of CTB-related cancer in the near future.

Albumin-Coated Single-Core Iron Oxide Nanoparticles for Enhanced Molecular Magnetic Imaging (MRI/MPI)

Colloidal stability of magnetic iron oxide nanoparticles (MNP) in physiological environments is crucial for their (bio)medical application. MNP are potential contrast agents for different imaging modalities such as magnetic resonance imaging (MRI) and magnetic particle imaging (MPI). Applied as a hybrid method (MRI/MPI), these are valuable tools for molecular imaging. Continuously synthesized and in-situ stabilized single-core MNP were further modified by albumin coating. Synthesizing and coating of MNP were carried out in aqueous media without using any organic solvent in a simple procedure. The additional steric stabilization with the biocompatible protein, namely bovine serum albumin (BSA), led to potential contrast agents suitable for multimodal (MRI/MPI) imaging. The colloidal stability of BSA-coated MNP was investigated in different sodium chloride concentrations (50 to 150 mM) in short- and long-term incubation (from two hours to one week) using physiochemical characterization techniques such as transmission electron microscopy (TEM) for core size and differential centrifugal sedimentation (DCS) for hydrodynamic size. Magnetic characterization such as magnetic particle spectroscopy (MPS) and nuclear magnetic resonance (NMR) measurements confirmed the successful surface modification as well as exceptional colloidal stability of the relatively large single-core MNP. For comparison, two commercially available MNP systems were investigated, MNP-clusters, the former liver contrast agent (Resovist), and single-core MNP (SHP-30) manufactured by thermal decomposition. The tailored core size, colloidal stability in a physiological environment, and magnetic performance of our MNP indicate their ability to be used as molecular magnetic contrast agents for MPI and MRI.

Recent progress in targeted delivery vectors based on biomimetic nanoparticles

Over the past decades, great interest has been given to biomimetic nanoparticles (BNPs) since the rise of targeted drug delivery systems and biomimetic nanotechnology. Biological vectors including cell membranes, extracellular vesicles (EVs), and viruses are considered promising candidates for targeted delivery owing to their biocompatibility and biodegradability. BNPs, the integration of biological vectors and functional agents, are anticipated to load cargos or camouflage synthetic nanoparticles to achieve targeted delivery. Despite their excellent intrinsic properties, natural vectors are deliberately modified to endow multiple functions such as good permeability, improved loading capability, and high specificity. Through structural modification and transformation of the vectors, they are pervasively utilized as more effective vehicles that can deliver contrast agents, chemotherapy drugs, nucleic acids, and genes to target sites for refractory disease therapy. This review summarizes recent advances in targeted delivery vectors based on cell membranes, EVs, and viruses, highlighting the potential applications of BNPs in the fields of biomedical imaging and therapy industry, as well as discussing the possibility of clinical translation and exploitation trend of these BNPs.

In Vivo Assessment of Hypoxia Levels in Pancreatic Tumors Using a Dual-Modality Ultrasound/Photoacoustic Imaging System

Noninvasive anatomical and functional imaging has become an essential tool to evaluate tissue oxygen saturation dynamics in preclinical or clinical studies of hypoxia. Our dual-wavelength technique for photoacoustic (PA) imaging based on the differential absorbance spectrum of oxyhemoglobin (oxy-Hb) and deoxyhemoglobin (deoxy-Hb) can quantify tissue oxygen saturation using the intrinsic contrast property. PA imaging of tissue oxygen saturation can be used to monitor tumor-related hypoxia, which is a particularly relevant functional parameter of the tumor microenvironment that has a strong influence on tumor aggressiveness. The simultaneous acquisition of anatomical and functional information using dual-modality ultrasound (US) and PA imaging technology enhances the preclinical applicability of the method. Here, the developed dual-modality US/PA system was used to measure relative tissue oxygenation using the dual-wavelength technique. Tissue oxygen saturation was quantified in a pancreatic tumor mouse model. The differences in tissue oxygenation were detected by comparing pancreatic samples from normal and tumor-bearing mice at various time points after implantation. The use of an in vivo pancreatic tumor model revealed changes in hypoxia at various stages of tumor growth. The US/PA imaging data positively correlated with the results of immunohistochemical staining for hypoxia. Thus, our dual-modality US/PA imaging system can be used to reliably assess and monitor hypoxia in pancreatic tumor mouse models. These findings enable the use of a combination of US and PA imaging to acquire anatomical and functional information on tumor growth and to evaluate treatment responses in longitudinal preclinical studies.

Ultra-high-frequency radio-frequency acoustic molecular imaging with saline nanodroplets in living subjects

Molecular imaging is a crucial technique in clinical diagnostics but it relies on radioactive tracers or strong magnetic fields that are unsuitable for many patients, particularly infants and pregnant women. Ultra-high-frequency radio-frequency acoustic (UHF-RF-acoustic) imaging using non-ionizing RF pulses allows deep-tissue imaging with sub-millimetre spatial resolution. However, lack of biocompatible and targetable contrast agents has prevented the successful in vivo application of UHF-RF-acoustic imaging. Here we report our development of targetable nanodroplets for UHF-RF-acoustic molecular imaging of cancers. We synthesize all-liquid nanodroplets containing hypertonic saline that are stable for at least 2 weeks and can produce high-intensity UHF-RF-acoustic signals. Compared with concentration-matched iron oxide nanoparticles, our nanodroplets produce at least 1,600 times higher UHF-RF-acoustic signals at the same imaging depth. We demonstrate in vivo imaging using the targeted nanodroplets in a prostate cancer xenograft mouse model expressing gastrin release protein receptor (GRPR), and show that targeting specificity is increased by more than 2-fold compared with untargeted nanodroplets or prostate cancer cells not expressing this receptor.

Biopolymer and Biomaterial Conjugated Iron Oxide Nanomaterials as Prostate Cancer Theranostic Agents: A Comprehensive Review

Prostate cancer (PCa) is the most common malignancy in men and the leading cause of death for men all over the world. Early diagnosis is the key to start treatment at an early stage of PCa and to reduce the death toll. Generally, PCa expresses characteristic morphologic features and serum biomarkers; however, early diagnosis is challenging due to its heterogeneity and long-term indolent phase in the early stage. Following positive diagnosis, PCa patients receive conventional treatments including surgery, radiation therapy, androgen deprivation therapy, focal therapy, and chemotherapy to enhance survival time and alleviate PCa-related complications. However, these treatment strategies have both short and long-term side effects, notably impotence, urinary incontinence, erectile dysfunctions, and recurrence of cancer. These limitations warrant the quest for novel PCa theranostic agents with robust diagnostic and therapeutic potentials to lessen the burden of PCa-related suffering. Iron oxide nanoparticles (IONPs) have recently drawn attention for their symmetrical usage in the diagnosis and treatment of several cancer types. Here, we performed a systematic search in four popular online databases (PubMed, Google Scholar, Scopus, and Web of Science) for the articles regarding PCa and IONPs. Published literature confirmed that the surface modification of IONPs with biopolymers and diagnostic biomarkers improved the early diagnosis of PCa, even in the metastatic stage with reliable accuracy and sensitivity. Furthermore, fine-tuning of IONPs with biopolymers, nucleic acids, anticancer drugs, and bioactive compounds can improve the therapeutic efficacy of these anticancer agents against PCa. This review covers the symmetrical use of IONPs in the diagnosis and treatment of PCa, investigates their biocompatibility, and examines their potential as PCa theranostic agents.

Plant tissue imaging with bipyramidal upconversion nanocrystals by introducing Tm3+ ions as energy trapping centers

Plant cell imaging is critical for agricultural production and plant pathology study. Advanced upconversion nanoparticles (UCNPs) are being developed as fluorescent probes for imaging cells and tissues in vivo and in vitro. Unfortunately, the thick cellulosic walls as barriers together with hemicelluloses and pectin hinder the entrance of macromolecules into the epidermal plant cell. Hence, realizing satisfactory temporal and spatial resolution with UCNPs remains an arduous task. Here, bipyramidal LiErF₄:1%Tm³⁺@LiYF₄ core-shell UCNPs with a super-bright red emission upon 980 nm laser excitation are explored, where the introduction of Tm³⁺ ions permits alleviation of the energy loss at defective sites and a significant improvement of the upconversion output. The as-obtained bipyramidal UCNPs could readily puncture plant cell walls and further penetrate into cell membranes, facilitating improved tissue imaging of cellular internalization, as demonstrated with the luminescence images obtained by multiphoton laser-scanning microscopy. Hence our work opens up a new avenue for exploring effective upconversion nanoparticles for achieving high resolution imaging of plant tissues.

Recent Advances in the Development of Magnetic Nanoparticles for Biomedical Applications

The unique properties of magnetic nanoparticles have led them to be considered materials with significant potential in the biomedical field. Nanometric size, high surface-area ratio, ability to function at molecular level, exceptional magnetic and physicochemical properties, and more importantly, the relatively easy tailoring of all these properties to the specific requirements of the different biomedical applications, are some of the key factors of their success. In this paper, we will provide an overview of the state of the art of different aspects of magnetic nanoparticles, specially focusing on their use in biomedicine. We will explore their magnetic properties, synthetic methods and surface modifications, as well as their most significative physicochemical properties and their impact on the in vivo behaviour of these particles. Furthermore, we will provide a background on different applications of magnetic nanoparticles in biomedicine, such as magnetic drug targeting, magnetic hyperthermia, imaging contrast agents or theranostics. Besides, current limitations and challenges of these materials, as well as their future prospects in the biomedical field will be discussed.

Nanotechnology-Based Strategies to Evaluate and Counteract Cancer Metastasis and Neoangiogenesis

Cancer metastasis is the major cause of cancer-related morbidity and mortality. It represents one of the greatest challenges in cancer therapy, both because of the ability of metastatic cells to spread into different organs, and because of the consequent heterogeneity that characterizes primary and metastatic tumors. Nanomaterials can potentially be used as targeting or detection agents owing to unique chemical and physical features that allow tailored and tunable theranostic functions. This review highlights nanomaterial-based approaches in the detection and treatment of cancer metastasis, with a special focus on the evaluation of nanostructure effects on cell migration, invasion, and angiogenesis in the tumor microenvironment.

Peptidyl Activity-Based Probes for Imaging Serine Proteases

Proteases catalyze the hydrolysis of peptide bonds. Products of this breakdown mediate signaling in an enormous number of biological processes. Serine proteases constitute the most numerous group of proteases, accounting for 40%, and they are prevalent in many physiological functions, both normal and disease-related functions, making them one of the most important enzymes in humans. The activity of proteases is controlled at the expression level by posttranslational modifications and/or endogenous inhibitors. The study of serine proteases requires specific reagents not only for detecting their activity but also for their imaging. Such tools include inhibitors or substrate-related chemical molecules that allow the detection of proteolysis and visual observation of active enzymes, thus facilitating the characterization of the activity of proteases in the complex proteome. Peptidyl activity-based probes (ABPs) have been extensively studied recently, and this review describes the basic principles in the design of peptide-based imaging agents for serine proteases, provides examples of activity-based probe applications and critically discusses their strengths, weaknesses, challenges and limitations.

Design, Synthesis and Binding Affinity Evaluation of Cytochrome P450 1B1 Targeted Chelators

BACKGROUND

Cytochrome P450 1B1 (CYP1B1) is specifically expressed in a variety of tumors which makes it a promise imaging target of tumor.

OBJECTIVE

We aimed to design and synthesize CYP1B1 targeted chelators for the potential application in positron emission tomography (PET) imaging of tumor.

METHODS

1,4,7-triazacyclononane-1,4-diiacetic acid (NODA) was connected to the CYP1B1 selective inhibitor we developed before through polyethylene glycol (PEG) linkers with different lengths. The inhibitory activities of chelators 6a-c against CYP1 family were evaluated by 7-ethoxyresorufin o-deethylation (EROD) assay. The manual docking between the chelators and the CYP1B1 are conducted subsequently. To determine the binding affinities of 6a-c to CYP1B1 in cells, we further performed a competition study at the cell level.

RESULTS

Among three chelators, 6a with the shortest linker showed the best inhibitory activity against CYP1B1. In the following molecular simulation study, protein-inhibitor complex of 6a showed the nearest F-heme distance which is consistent with the results of enzymatic assay. Finally, the cell based competitive assay proved the binding affinity of 6a-c to CYP1B1 enzyme.

CONCLUSION

We designed and synthesized a series of chelators which can bind to CYP1B1 enzyme in cancer cells.To our knowledge, this work is the first attempt to construct CYP1B1 targeted chelators for radiolabeling and we hope it will prompt the application of CYP1B1 imaging in tumor detection.

A Cyclodextrin-Hosted Ir(III) Complex for Ratiometric Mapping of Tumor Hypoxia In Vivo

Hypoxia is considered as a key microenvironmental feature of solid tumors. Luminescent transition metal complexes particularly those based on iridium and ruthenium have shown remarkable potentials for constructing sensitive oxygen-sensing probes due to their unique oxygen quenching pathway. However, the low aqueous solubility of these complexes largely retards their sensing applications in biological media. Moreover, it remains difficult so far to use the existing complexes typically possessing only one luminescent domain to quantitatively detect the intratumoral hypoxia degree. Herein, an Ir(III) complex showing red emissions is designed and synthesized, and innovatively encapsulated within a hydrophobic pocket of Cyanine7-modified cyclodextrin. The Ir(III) complex enables the oxygen detection, while the cyclodextrin is used not only for improving the water solubility and suppressing the luminescence quenching effect of the surrounding aqueous media, but also for carrying Cyanine7 to establish a ratiometric oxygen fluorescence probe. 2D nuclear magnetic resonance is carried out to confirm the host-guest structure. The oxygen-responsive ability of the resulting ratiometric probe is evaluated through in vitro cell and multicellular experiments. Further animal studies about tumor oxygen level mapping demonstrate that the probe can be successfully used for quantitatively visualizing tumor hypoxia in vivo.

Recent advances in iron oxide nanoparticles for brain cancer theranostics: from in vitro to clinical applications

Introduction: Today, the development of multifunctional nanoplatforms is more seriously considered in the field of cancer theranostics.Areas covered: In this respect, nanoparticles provide several advantages over the routine, conventional diagnostic methods, and treatments. Due to the expedient properties of iron oxide nanoparticles, such as being readily modified, great payload potential, intrinsic magnetic qualification, considerable biocompatibility, and overwhelming response to targeting strategies, these nanoparticles can be considered good candidates for application as diagnostic contrast agents and drug/gene delivery vehicles, while also being incorporated into hyperthermia-based approaches. Interestingly, these agents are detectable with routine imaging modalities such as magnetic resonance imaging.Expert opinion: Therefore, combining the traditional diagnostics and therapies with nanotechnological approaches may leave a positive impact on the survival rate of patients with cancer. This review summarizes the application of magnetic iron oxide nanoparticles in both in vitro and in vivo models of brain tumors.

Near-Infrared Fluorescent Probe Activated by Nitroreductase for In Vitro and In Vivo Hypoxic Tumor Detection

Tumor hypoxia is correlated with increased resistance to chemotherapy and poor overall prognoses across a number of cancer types. We present here a cancer cell-selective and hypoxia-responsive probe (fol-BODIPY) designed on the basis of density functional theory (DFT)-optimized quantum chemical calculations. The fol-BODIPY probe was found to provide a rapid fluorescence "off-on" response to hypoxia relative to controls, which lack the folate or nitro-benzyl moieties. In vitro confocal microscopy and flow cytometry analyses, as well as in vivo near-infrared optical imaging of CT26 solid tumor-bearing mice, provided support for the contention that fol-BODIPY is more readily accepted by folate receptor-positive CT26 cancer cells and provides a superior fluorescence "off-on" signal under hypoxic conditions than the controls. Based on the findings of this study, we propose that fol-BODIPY may serve as a tumor-targeting, hypoxia-activatable probe that allows for direct cancer monitoring both in vitro and in vivo.

Dendrimers based cancer nanotheranostics: An overview

Cancer is a known deadliest disease that requires a judicious diagnostic, targeting, and treatment strategy for an early prognosis and selective therapy. The major pitfalls of the conventional approach are non-specificity in targeting, failure to precisely monitor therapy outcome, and cancer progression leading to malignancies. The unique physicochemical properties offered by nanotechnology derived nanocarriers have the potential to radically change the landscape of cancer diagnosis and therapeutic management. An integrative approach of utilizing both diagnostic and therapeutic functionality using a nanocarrier is termed as nanotheranostic. The nanotheranostics platform is designed in such a way that overcomes various biological barriers, efficiently targets the payload to the desired locus, and simultaneously supports planning, monitoring, and verification of treatment delivery to demonstrate an enhanced therapeutic efficacy. Thus, a nanotheranostic platform could potentially assist in drug targeting, image-guided focal therapy, drug release and distribution monitoring, predictionof treatment response, and patient stratification. A class of highly branched nanocarriers known as dendrimers is recognized as an advanced nanotheranostic platform that has the potential to revolutionize the oncology arena by its unique and exciting features. A dendrimer is a well-defined three-dimensional globular chemical architecture with a high level of monodispersity, amenability of precise size control, and surface functionalization. All the dendrimer properties exhibit a reproducible pharmacokinetic behavior that could ensure the desired biodistribution and efficacy. Dendrimers are thus being exploited as a nanotheranostic platform embodying a diverse class of therapeutic, imaging, and targeting moieties for cancer diagnosis and treatment.

Molecularly targeted nanoparticles: an emerging tool for evaluation of expression of the receptor for advanced glycation end products in a murine model of peripheral artery disease

Background

Molecular imaging with molecularly targeted probes is a powerful tool for studying the spatio-temporal interactions between complex biological processes. The pivotal role of the receptor for advanced glycation end products (RAGE), and its involvement in numerous pathological processes, aroused the demand for RAGE-targeted imaging in various diseases. In the present study, we evaluated the use of a diagnostic imaging agent for RAGE quantification in an animal model of peripheral artery disease, a multimodal dual-labeled probe targeted at RAGE (MMIA-CML).

Methods

PAMAM dendrimer was conjugated with Nε-carboxymethyl-lysine (CML) modified albumin to synthesize the RAGE-targeted probe. A control untargeted agent carried native non-modified human albumin (HSA). Bifunctional p-SCN-Bn-NOTA was used to conjugate the ⁶⁴Cu radioisotope. Surgical right femoral artery ligation was performed on C57BL/6 male mice. One week after femoral artery ligation, mice were injected with MMIA-CML or MMIA-HSA labeled with ⁶⁴Cu radioisotope and 60 min later in vivo microPET-CT imaging was performed. Immediately after PET imaging studies, the murine hindlimb muscle tissues were excised and prepared for gene and protein expression analysis. RAGE gene and protein expression was assessed using real-time qPCR and Western blot technique respectively. To visualize RAGE expression in excised tissues, microscopic fluorescence imaging was performed using RAGE-specific antibodies and RAGE-targeted and -control MMIA.

Results

Animals subjected to PET imaging exhibited greater MMIA-CML uptake in ischemic hindlimbs than non-ischemic hindlimbs. We observed a high correlation between fluorescent signal detection and radioactivity measurement. Significant RAGE gene and protein overexpression were observed in ischemic hindlimbs compared to non-ischemic hindlimbs at one week after surgical ligation. Fluorescence microscopic staining revealed significantly increased uptake of RAGE-targeted nanoparticles in both ischemic and non-ischemic muscle tissues compared to the control probe but at a higher level in ischemic hindlimbs. Ischemic tissue exhibited explicit RAGE dyeing following anti-RAGE antibody and high colocalization with the MMIA-CML targeted at RAGE.

Conclusions

The present results indicate increased expression of RAGE in the ischemic hindlimb and enable the use of multimodal nanoparticles in both in vitro and in vivo experimental models, creating the possibility for imaging structural and functional changes with a RAGE-targeted tracer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11658-021-00253-0.

Fluorescent Probe for Monitoring Hydrogen Peroxide in COX-2-Positive Cancer Cells

Hydrogen peroxide (H₂O₂), an important marker for oxidative stress, plays a vital role in cellular biological functions. Overproduction of H₂O₂ causes oxidative damage to cellular functions and promotes cancer and other neurodegenerative diseases. Also, cyclooxygenase-2 (COX-2) enzyme is known to be expressed in several cancer types and exerts multifaceted roles in carcinogenesis and resistance to cancer treatment. Hence, it is important to monitor the H₂O₂ concentration changes in the COX-2-expressing cancer cells. Herein, we have developed a molecular fluorescent ratiometric H₂O₂-responsive probe (NPDIN) composed of indomethacin (COX-2 inhibitor) conjugated with 1,8-napthalimide boronate ester as fluorescent reporter through a chemical linker. The probe was capable of imaging the endogenous H₂O₂ in COX-2 overexpressing cancer cell lines (A549, LoVo, HT29, and Caco-2). Further studies revealed the critical role of the indomethacin moiety in the cellular uptake behavior of NPDIN in COX-2-overexpressing cancer cells. Collectively, our results demonstrated NPDIN as a COX-2-positive cancer-targeting sensitive ratiometric fluorescent probe (I₅₅₄/I₃₉₈) for H₂O₂ imaging and showed its promising biological applications in the future.

DOTAM-Based, Targeted, Activatable Fluorescent Probes for the Highly Sensitive and Selective Detection of Cancer Cells

The utilization of an activatable, substrate-based probe design in combination with a cellular targeting approach has been rarely explored for cancer imaging on a small-molecule basis, although such probes could benefit from advantages of both concepts. Cysteine proteases like cathepsin S are known to be involved in fundamental processes associated with tumor development and progression and thus are valuable cancer markers. We report the development of a combined dual functional DOTAM-based, RGD-targeted internally quenched fluorescent probe that is activated by cathepsin S. The probe exhibits excellent in vitro activation kinetics which can be fully translated to human cancer cell lines. We demonstrate that the targeted, activatable probe is superior to its nontargeted analog, exhibiting improved uptake into α_νβ₃-integrin expressing human sarcoma cells (HT1080) and significantly higher resultant fluorescence staining. However, profound activation was also found in cancer cells with a lower integrin expression level, whereas in healthy cells almost no probe activation could be observed, highlighting the high selectivity of our probe toward cancer cells. These auspicious results show the outstanding potential of the dual functionality concept combining a substrate-based probe design with a targeting approach, which could form the basis for highly sensitive and selective in vivo imaging probes.

Nuclear hyperpolarization of (1-13C)-pyruvate in aqueous solution by proton-relayed side-arm hydrogenation

We employ Parahydrogen Induced Polarization with Side-Arm Hydrogenation (PHIP-SAH) to polarize (1-13C)-pyruvate. We introduce a new method called proton-relayed side-arm hydrogenation (PR-SAH) in which an intermediate proton is used to transfer polarization from the side-arm to the 13C-labelled site of the pyruvate before hydrolysis. This significantly reduces the cost and effort needed to prepare the precursor for radio-frequency transfer experiments while still maintaining acceptable polarization transfer efficiency. Experimentally we have attained on average 4.33% 13C polarization in an aqueous solution of (1-13C)-pyruvate after about 10 seconds of cleavage and extraction. PR-SAH is a promising pulsed NMR method for hyperpolarizing 13C-labelled metabolites in solution, conducted entirely in high magnetic field.

Ultrasound lighting up AIEgens for potential surgical navigation

Multifunctional contrast-enhanced agents suitable for application in surgical navigation by taking advantage of the merits of their diverse imaging modalities at different surgical stages are highly sought-after. Herein, an amphipathic polymer composed of aggregation-induced emission fluorogens (AIEgens) and Gd³⁺ chelates was successfully synthesized and assembled into ultrasound responsive microbubbles (AIE-Gd MBs) to realize potential tri-modal contrast-enhanced ultrasound (US) imaging, magnetic resonance imaging (MRI), and AIEgen-based fluorescence imaging (FI) during the perioperative period. Through ultrasound targeted microbubble destruction (UTMD) and cavitation effect, the as-prepared AIE-Gd MBs went through a MBs-to-nanoparticles (NPs) conversion, which not only resulted in targeted accumulation in tumor tissues but also led to stronger fluorescence being exhibited due to the more aggregated AIE-Gd molecules in the NPs. As a proof-of-concept, our work proposes a strategy of US-lit-up AIEgens in tumors which could offer a simple and powerful tool for surgical navigation in the future.

Near-infrared fluorescence-guided resection of micrometastases derived from esophageal squamous cell carcinoma using a c-Met-targeted probe in a preclinical xenograft model

The postoperative survival of esophageal squamous cell carcinoma (eSCC) is notably hindered by cancer recurrence due to difficulty in identifying occult metastases. Cellular mesenchymal-epithelial transition factor (c-Met), which is highly expressed in different cancers, including eSCC, has become a target for the development of imaging probes and therapeutic antibodies. In this study, we synthesized an optical probe (SHRmAb-IR800) containing a near-infrared fluorescence (NIRF) dye and c-Met antibody, which may help in NIRF-guided resection of micrometastases derived from eSCC. Cellular uptake of SHRmAb-IR800 was assessed by flow cytometry and confocal microscopy. In vivo accumulation of SHRmAb-IR800 and the potential application of NIRF-guided surgery were evaluated in eSCC xenograft tumor models. c-Met expression in human eSCC samples and lymph node metastases (LNMs) was analyzed via immunohistochemistry (IHC). Cellular accumulation of SHRmAb-IR800 was higher in c-Met-positive EC109 eSCC cells than in c-Met-negative A2780 cells. Infusion of SHRmAb-IR800 produced higher fluorescence intensity and a higher tumor-to-background ratio (TBR) than the control probe in EC109 subcutaneous tumors (P < 0.05). The TBRs of orthotopic EC109 tumors and LNMs were 3.01 ± 0.17 and 2.77 ± 0.56, respectively. The sensitivity and specificity of NIRF-guided resection of metastases derived from orthotopic cancers were 92.00% and 89.74%, respectively. IHC results demonstrated positive staining in 97.64% (124/127) of eSCC samples and 91.67% (55/60) of LNMs. Notably, increased c-Met expression was observed in LNMs compared to normal lymph nodes (P < 0.0001). Taken together, the results of this study indicated that SHRmAb-IR800 facilitated the resection of micrometastases of eSCC in the xenograft tumor model. This c-Met-targeted probe possesses translational potential in NIRF-guided surgery due to the high positive rate of c-Met protein in human eSCCs.

Exploring Solvent Effects in the Radiosynthesis of 18F-Labeled Thymidine Analogues toward Clinical Translation for Positron Emission Tomography Imaging

Thymidine analogues, 5-substituted 2'-deoxy-2'-[¹⁸F]fluoro-arabinofuranosyluracil derivatives, are promising positron emission tomography (PET) tracers being evaluated for noninvasive imaging of cancer cell proliferation and/or reporter gene expression. We report the radiosynthesis of 2'-deoxy-2'-[¹⁸F]fluoro-5-methyl-1-β-d-arabinofuranosyluracil ([¹⁸F]FMAU) and other 2'-deoxy-2'-[¹⁸F]fluoro-5-substituted-1-β-d-arabinofuranosyluracil analogues using 1,4-dioxane to replace the currently used 1,2-dichloroethane. Compared to 1,2-dichloroethane, 1,4-dioxane is analyzed as a better solvent in terms of radiochemical yield and toxicity concern. The use of a less toxic solvent allows for the translation of the improved approach to clinical production. The new radiolabeling method can be applied to an extensive range of uses for ¹⁸F-labeling of other nucleoside analogues.

Photoacoustic Imaging and Photothermal Therapy of Semiconducting Polymer Nanoparticles: Signal Amplification and Second Near-Infrared Construction

Photoacoustic (PA) imaging and photothermal therapy (PTT) have attracted extensive attention in disease diagnosis and treatment. Although many exogenous contrast agents have been developed for PA imaging and PTT, the design guidelines to amplify their imaging and therapy performances remain challenging and are highly demanded. Semiconducting polymer nanoparticles (SPNs) composed of polymers with π-electron delocalized backbones can be designed to amplify their PA imaging and PTT performance, because of their clear structure-property relation and versatility in modifying their molecular structures to tune their photophysical properties. This review summarizes the recent advances in the photoacoustic imaging and photothermal therapy applications of semiconducting polymer nanoparticles with a focus on signal amplification and second near-infrared (NIR-II, 1000-1700 nm) construction. The strategies such as structure-property screening, fluorescence quenching, accelerated heat dissipation, and size-dependent heat dissipation are first discussed to amplify the PA brightness of SPNs for in vivo PA. The molecular approaches to shifting the absorption of SPNs for NIR-II PA imaging and PTT are then introduced so as to improve the tissue penetration depth for diagnosis and therapy. At last, current challenges and perspectives of SPNs in the field of imaging and therapy are discussed.

Targeting Glycans and Heavily Glycosylated Proteins for Tumor Imaging

Simple Summary

Distinguishing malignancy from healthy tissue is essential for oncologic surgery. Targeted imaging during an operation aids the surgeon to operate better. The present tracers for detecting cancer are directed against proteins that are overexpressed on the membrane of tumor cells. This review evaluates the use of tumor-associated sugar molecules as an alternative for proteins to image cancer tissue. These sugar molecules are present as glycans on glycosylated membrane proteins and glycolipids. Due to their location and large numbers per cell, these sugar molecules might be better targets for tumor imaging than proteins.

Abstract

Real-time tumor imaging techniques are increasingly used in oncological surgery, but still need to be supplemented with novel targeted tracers, providing specific tumor tissue detection based on intra-tumoral processes or protein expression. To maximize tumor/non-tumor contrast, targets should be highly and homogenously expressed on tumor tissue only, preferably from the earliest developmental stage onward. Unfortunately, most evaluated tumor-associated proteins appear not to meet all of these criteria. Thus, the quest for ideal targets continues. Aberrant glycosylation of proteins and lipids is a fundamental hallmark of almost all cancer types and contributes to tumor progression. Additionally, overexpression of glycoproteins that carry aberrant glycans, such as mucins and proteoglycans, is observed. Selected tumor-associated glyco-antigens are abundantly expressed and could, thus, be ideal candidates for targeted tumor imaging. Nevertheless, glycan-based tumor imaging is still in its infancy. In this review, we highlight the potential of glycans, and heavily glycosylated proteoglycans and mucins as targets for multimodal tumor imaging by discussing the preclinical and clinical accomplishments within this field. Additionally, we describe the major advantages and limitations of targeting glycans compared to cancer-associated proteins. Lastly, by providing a brief overview of the most attractive tumor-associated glycans and glycosylated proteins in association with their respective tumor types, we set out the way for implementing glycan-based imaging in a clinical practice.

Sound Out the Deep Colors: Photoacoustic Molecular Imaging at New Depths

Photoacoustic tomography (PAT) has become increasingly popular for molecular imaging due to its unique optical absorption contrast, high spatial resolution, deep imaging depth, and high imaging speed. Yet, the strong optical attenuation of biological tissues has traditionally prevented PAT from penetrating more than a few centimeters and limited its application for studying deeply seated targets. A variety of PAT technologies have been developed to extend the imaging depth, including employing deep-penetrating microwaves and X-ray photons as excitation sources, delivering the light to the inside of the organ, reshaping the light wavefront to better focus into scattering medium, as well as improving the sensitivity of ultrasonic transducers. At the same time, novel optical fluence mapping algorithms and image reconstruction methods have been developed to improve the quantitative accuracy of PAT, which is crucial to recover weak molecular signals at larger depths. The development of highly-absorbing near-infrared PA molecular probes has also flourished to provide high sensitivity and specificity in studying cellular processes. This review aims to introduce the recent developments in deep PA molecular imaging, including novel imaging systems, image processing methods and molecular probes, as well as their representative biomedical applications. Existing challenges and future directions are also discussed.

Studies of nanoparticle delivery with in vitro bio-engineered microtissues

A variety of engineered nanoparticles, including lipid nanoparticles, polymer nanoparticles, gold nanoparticles, and biomimetic nanoparticles, have been studied as delivery vehicles for biomedical applications. When assessing the efficacy of a nanoparticle-based delivery system, in vitro testing with a model delivery system is crucial because it allows for real-time, in situ quantitative transport analysis, which is often difficult with in vivo animal models. The advent of tissue engineering has offered methods to create experimental models that can closely mimic the 3D microenvironment in the human body. This review paper overviews the types of nanoparticle vehicles, their application areas, and the design strategies to improve delivery efficiency, followed by the uses of engineered microtissues and methods of analysis. In particular, this review highlights studies on multicellular spheroids and other 3D tissue engineering approaches for cancer drug development. The use of bio-engineered tissues can potentially provide low-cost, high-throughput, and quantitative experimental platforms for the development of nanoparticle-based delivery systems.

DNA Nanostructures and DNA-Functionalized Nanoparticles for Cancer Theranostics

In the last two decades, DNA has attracted significant attention toward the development of materials at the nanoscale for emerging applications due to the unparalleled versatility and programmability of DNA building blocks. DNA-based artificial nanomaterials can be broadly classified into two categories: DNA nanostructures (DNA-NSs) and DNA-functionalized nanoparticles (DNA-NPs). More importantly, their use in nanotheranostics, a field that combines diagnostics with therapy via drug or gene delivery in an all-in-one platform, has been applied extensively in recent years to provide personalized cancer treatments. Conveniently, the ease of attachment of both imaging and therapeutic moieties to DNA-NSs or DNA-NPs enables high biostability, biocompatibility, and drug loading capabilities, and as a consequence, has markedly catalyzed the rapid growth of this field. This review aims to provide an overview of the recent progress of DNA-NSs and DNA-NPs as theranostic agents, the use of DNA-NSs and DNA-NPs as gene and drug delivery platforms, and a perspective on their clinical translation in the realm of oncology.

Nanobodies in cancer

For treatment and diagnosis of cancer, antibodies have proven their value and now serve as a first line of therapy for certain cancers. A unique class of antibody fragments called nanobodies, derived from camelid heavy chain-only antibodies, are gaining increasing acceptance as diagnostic tools and are considered also as building blocks for chimeric antigen receptors as well as for targeted drug delivery. The small size of nanobodies (∼15 kDa), their stability, ease of manufacture and modification for diverse formats, short circulatory half-life, and high tissue penetration, coupled with excellent specificity and affinity, account for their attractiveness. Here we review applications of nanobodies in the sphere of tumor biology.

Red blood cell membrane-coated upconversion nanoparticles for pretargeted multimodality imaging of triple-negative breast cancer

Upconversion nanoparticles (UCNPs) have been widely employed for tumor imaging using magnetic resonance imaging (MRI) and upconversion luminescence (UCL) imaging. The short blood clearance time and immunogenicity of UCNPs have limited their further application in vivo. We have designed UCNPs camouflaged with an exterior red blood cell (RBC) membrane coating (RBC-UCNPs) to solve these problems. Moreover, because of some intrinsic disadvantages of MRI and UCL imaging, we investigated the use of pretargeted RBC-UCNPs for positron-emission tomography (PET) imaging to obtain more comprehensive information. Our data showed that RBC-UCNPs retained the immunity feature from the source cells and the superior optical and chemical features from the pristine UCNP cores. The tumor-targeting ability of RBC-UCNPs was enhanced by binding 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[folate(polyethylene glycol)-2000] (DSPE-PEG-FA) molecules onto the cell membranes. PET imaging with short half-life radionuclides to visualize the RBC-UCNPs was successfully realized by a combination of pre-targeting and in vivo click chemistry. Blood chemistry, hematology, and histologic analysis suggested good in vivo biocompatibility of the RBC-UCNPs. Our method provides a new potential biomedical application of biomimetic nanoparticles.

Synthesis of a novel β-cyclodextrin-functionalized Fe3O4/BaMoO4:Dy3+ magnetic luminescent hybrid nanomaterial and its application as a drug carrier

Magnetic luminescent hybrid nanoparticles Fe3O4/BaMoO4:Dy3+ (MLHNPs) were successfully synthesized by the co-precipitation method using ethylene glycol. The MLHNPs are functionalized with β-cyclodextrin (CD) using 3-aminopropyl triethoxysilane (APTES). The surface functionalization of nanoparticles and their conjugation have been confirmed via powder XRD, FTIR, HRTEM, and PL analyses. The feasibility of functionalized MLHNPs as nanocarriers for hydrophobic drugs (triazole derivatives) was verified by studying the uptake and release profile using a triazole derivative as a hydrophobic drug. In addition, the photoluminescence spectroscopy results confirmed the optical imaging capability of MLHNPs. The outcomes of loading and release disclose that this system is likely to be a suitable tool as a hydrophobic drug carrier.

The Oncolytic Virus in Cancer Diagnosis and Treatment

Cancer has always been an enormous threat to human health and survival. Surgery, radiotherapy, and chemotherapy could improve the survival of cancer patients, but most patients with advanced cancer usually have a poor survival or could not afford the high cost of chemotherapy. The emergence of oncolytic viruses provided a new strategy for us to alleviate or even cure malignant tumors. An oncolytic virus can be described as a genetically engineered or naturally existing virus that can selectively replicate in cancer cells and then kill them without damaging the healthy cells. There have been many kinds of oncolytic viruses, such as herpes simplex virus, adenovirus, and Coxsackievirus. Moreover, they have different clinical applications in cancer treatment. This review focused on the clinical application of oncolytic virus and predicted the prospect by analyzing the advantages and disadvantages of oncolytic virotherapy.

Bone-targeting polymer vesicles for simultaneous imaging and effective malignant bone tumor treatment

We present a bone-targeting polymer vesicle with excellent single photon emission computed tomography/computed tomography (SPECT/CT) imaging capability and high antitumor drug delivery efficiency as an integrated platform for the simultaneous diagnosing and treatment of malignant bone tumors. This polymer vesicle can be self-assembled from poly(ε-caprolactone)₆₇-b-poly[(L-glutamic acid)₆-stat-(L-glutamic acid-alendronic acid)₁₆] (PCL₆₇-b-P[Glu₆-stat-(Glu-ADA)₁₆]), directly in water without the aid of a cosolvent. SPECT/CT dynamically tracked the drug distribution in the bone tumor rabbit models, and the tumor size was significantly reduced from >2.0 cm³ to <0.6 cm³ over 11 days. The pathological analysis demonstrated obvious necrosis and apoptosis of the tumor cells. Overall, this bone-targeting polymer vesicle provides us with a new platform for the combination of real-time diagnosis and therapy of malignant bone tumors.

Polymeric Nanoparticles for Drug Delivery: Recent Developments and Future Prospects

The complexity of some diseases—as well as the inherent toxicity of certain drugs—has led to an increasing interest in the development and optimization of drug-delivery systems. Polymeric nanoparticles stand out as a key tool to improve drug bioavailability or specific delivery at the site of action. The versatility of polymers makes them potentially ideal for fulfilling the requirements of each particular drug-delivery system. In this review, a summary of the state-of-the-art panorama of polymeric nanoparticles as drug-delivery systems has been conducted, focusing mainly on those applications in which the corresponding disease involves an important morbidity, a considerable reduction in the life quality of patients—or even a high mortality. A revision of the use of polymeric nanoparticles for ocular drug delivery, for cancer diagnosis and treatment, as well as nutraceutical delivery, was carried out, and a short discussion about future prospects of these systems is included.

A novel luminescent Ir(iii) complex for dual mode imaging: synergistic response to hypoxia and acidity of the tumor microenvironment

The early detection of cancer shows great promise for the control and prevention of cancer. For early detection, one of the challenges that still exists is searching for methods that can illuminate tumors with high sensitivity. Here, acidity and hypoxia, two typical features that exist universally in a solid tumor microenvironment, were focused on to attain synergistic imaging with an enhanced signal-to-noise ratio. This was realized using an iridium(iii) based optical probe (Ir-1) that could sense acidity and hypoxia simultaneously and synergistically. Through the synergistic sensing of acidic pH and hypoxia, stronger emission signals or larger lifetime changes can be obtained than if a single factor (acidity or hypoxia) is used to induce variations. Furthermore, its potential for biological applications was confirmed by employing Ir-1 for phosphorescence synergistic intensity and lifetime imaging of acidity and hypoxia in live monolayer cells and 3D multicellular spheroids.

Enzyme-activated anchoring of peptide probes onto plasma membranes for selectively lighting up target cells

In a cellular microenvironment, numerous biomolecules are involved in various physiological and pathological processes. However, for the in-depth and comprehensive understanding of their roles at the molecular level, there is still a lack of detection techniques for the in situ tracking of these biomolecules in a local environment. Herein, we engineered a membrane insertion peptide (MIP) as an enzyme-activated membrane insertion peptide probe (eaMIP) that allowed the in situ tracking of the activity of target enzymes in living cells. In this strategy, the membrane insertion capacity of the MIP motif in each eaMIP was caged by appending a chemical moiety. In the presence of target enzymes, the caging moiety in each eaMIP was removed by enzymatic decaging, leading to the generation of active MIPs. The versatility of this design was demonstrated by lighting up different tumor cells with distinct fluorescence signal patterns, affording an alternative tool for clinical diagnostics, biochemical research and membrane engineering.

The role of integrins in melanoma: a review

Integrins are the major family of cell adhesion receptors in humans and essential for a wide range of normal physiology, including formation and maintenance of tissue structure integrity, cell migration, proliferation, and differentiation. Integrins also play a prominent role in tumor growth and metastasis. Translational research has tried to define the contribution of integrins to the phenotypic aggressiveness of melanoma because such knowledge is clinically useful. For example, differential expression of integrins in primary cutaneous melanoma can be used to distinguish indolent from aggressive, prometastatic melanoma. Recent studies have shown that gene expression-based testing of patient-derived melanoma tissue is feasible, and molecular tests may fully replace interventional surgical methods such as sentinel lymph node biopsies in the future. Because of their central role in mediating invasion and metastasis, integrins are likely to be useful biomarkers. Integrins are also attractive candidate targets for interventional therapy. This article focuses on the role of integrins in melanoma and highlights recent advances in the field of translational research.

Spectral-Fluorescence Properties of Zn(II)-Octaphenyltetraazaporphyrins

Zn(II)-octa-(4-chlorophenyl)- and Zn(II)-octa-(4-bromophenyl)tetraazaporphyrins were synthesized by the reaction of cyclotetramerization of di-(4-chlorophenyl)- and di-(4-bromophenyl)maleonitriles with zinc(II) chloride. The obtained compounds were identified by UV-vis, IR, NMR 1H spectroscopy and mass spectrometry. Geometry optimization of the series of halogenated Zn(II)-octaaryltetraazaporphyrins was performed using the density functional method with the BP86 functional and the def2-TZVP basis set. An analysis of the distribution of molecular orbital energies in the neighborhood of highest occupied molecular orbitals (HOMO and HOMO-1) and lowest unoccupied molecular orbitals (LUMO and LUMO+1) and the width of the HOMO - LUMO energy gaps (EH-L) was performed for the studied compounds. Fluorimetric measurements of the Zn(II)-octaphenyltetraazaporphyrins in toluene were carried out and fluorescence quantum yields of studied compounds were determined and analyzed. It has been shown that the halogen on the para-position of the phenyl groups significantly affects the value of the obtained quantum yields of fluorescence emission but does not significantly affect the Stokes shifts.

Virotheranostics, a double-barreled viral gun pointed toward cancer; ready to shoot?

Compared with conventional cancer treatments, the main advantage of oncolytic virotherapy is its tumor-selective replication followed by the destruction of malignant cells without damaging healthy cells. Accordingly, this kind of biological therapy can potentially be used as a promising approach in the field of cancer management. Given the failure of traditional monitoring strategies (such as immunohistochemical analysis (in providing sufficient safety and efficacy necessary for virotherapy and continual pharmacologic monitoring to track pharmacokinetics in real-time, the development of alternative strategies for ongoing monitoring of oncolytic treatment in a live animal model seems inevitable. Three-dimensional molecular imaging methods have recently been considered as an attractive approach to overcome the limitations of oncolytic therapy. These noninvasive visualization systems provide real-time follow-up of viral progression within the cancer tissue by the ability of engineered oncolytic viruses (OVs) to encode reporter transgenes based on recombinant technology. Human sodium/iodide symporter (hNIS) is considered as one of the most prevalent nuclear imaging reporter transgenes that provides precise information regarding the kinetics of gene expression, viral biodistribution, toxicity, and therapeutic outcomes using the accumulation of radiotracers at the site of transgene expression. Here, we provide an overview of pre-clinical and clinical applications of hNIS-based molecular imaging to evaluate virotherapy efficacy. Moreover, we describe different types of reporter genes and their potency in the clinical trials.

Melanin-based nanomaterials: The promising nanoplatforms for cancer diagnosis and therapy

Melanin-based nanoplatforms are biocompatible nanomaterials with a variety of unique physicochemical properties such as strong photothermal conversion ability, excellent drug binding capacity, strong metal chelation capacity, high chemical reactivity and versatile adhesion ability. These innate talents not only make melanin-based nanoplatforms be an inborn theranostic nanoagent for photoacoustic imaging-guided photothermal therapy of cancers, but also enable them to be conveniently transferred into cancer-targeting drug delivery systems and multimodality imaging nanoprobes. Due to the intriguing properties, melanin-based nanoplatforms have attracted much attention in investigations of cancer diagnosis and therapy. This review provides an overview of recent research advances in applications of melanin-based nanoplatforms in the fields of cancer diagnosis and therapy including cancer photothermal therapy, anticancer drug delivery, cancer-specific multimodal imaging and theranostics, etc. The remaining challenges and prospects of melanin-based nanoplatforms in biomedical applications are discussed at the end of this review.

Activity-Based Diagnostics: An Emerging Paradigm for Disease Detection and Monitoring

Diagnostics to accurately detect disease and monitor therapeutic response are essential for effective clinical management. Bioengineering, chemical biology, molecular biology, and computer science tools are converging to guide the design of diagnostics that leverage enzymatic activity to measure or produce biomarkers of disease. We review recent advances in the development of these 'activity-based diagnostics' (ABDx) and their application in infectious and noncommunicable diseases. We highlight efforts towards both molecular probes that respond to disease-specific catalytic activity to produce a diagnostic readout, as well as diagnostics that use enzymes as an engineered component of their sense-and-respond cascade. These technologies exemplify how integrating techniques from multiple disciplines with preclinical validation has enabled ABDx that may realize the goals of precision medicine.

Nanotechnological Strategies for Osteoarthritis Diagnosis, Monitoring, Clinical Management, and Regenerative Medicine: Recent Advances and Future Opportunities

PURPOSE OF REVIEW

In this review article, we discuss the potential for employing nanotechnological strategies for the diagnosis, monitoring, and clinical management of osteoarthritis (OA) and explore how nanotechnology is being integrated rapidly into regenerative medicine for OA and related osteoarticular disorders.

RECENT FINDINGS

We review recent advances in this rapidly emerging field and discuss future opportunities for innovations in enhanced diagnosis, prognosis, and treatment of OA and other osteoarticular disorders, the smart delivery of drugs and biological agents, and the development of biomimetic regenerative platforms to support cell and gene therapies for arresting OA and promoting cartilage and bone repair. Nanotubes, magnetic nanoparticles, and other nanotechnology-based drug and gene delivery systems may be used for targeting molecular pathways and pathogenic mechanisms involved in OA development. Nanocomposites are also being explored as potential tools for promoting cartilage repair. Nanotechnology platforms may be combined with cell, gene, and biological therapies for the development of a new generation of future OA therapeutics. Graphical Abstract.

Active matter therapeutics

Nanotherapies based on micelles, liposomes, polymersomes, nanocapsules, magnetic nanoparticles, and noble metal nanoparticles have been at the forefront of drug delivery in the past few decades. Some of these nanopharmaceuticals have been commercially applied to treat a wide range of diseases, from dry eye syndrome to cancer. However, the majority involve particles that are passive, meaning that they do not change shape, and they lack motility; the static features can limit their therapeutic efficacy. In this review, we take a critical look at an emerging field that seeks to utilize active matter for therapeutics. In this context, active matter can be broadly referred to as micro or nanosized constructs that energetically react with their environment or external fields and translate, rotate, vibrate or change shape. Essentially, the recent literature suggests that such particles could significantly augment present-day drug delivery, by enhancing transport and increasing permeability across anatomical barriers by transporting drugs within solid tumor microenvironments or disrupting cardiovascular plaque. We discuss examples of such particles and link the transport and permeability properties of active matter to potential therapeutic applications in the context of two major diseases, namely cancer and heart disease. We also discuss potential challenges, opportunities, and translational hurdles.