Targeted Near-Infrared Fluorescent Turn-on Nanoprobe for Activatable Imaging and Effective Phototherapy of Cancer Cells

An Indocyanine Green-Based Nanocluster for Imaging Orthodox Endometriosis Lesions with Negative Contrast

Indocyanine green (ICG), as the sole near-infrared dye FDA-approved, is limited in biomedical applications because of its poor photostability, lack of targeting, and rapid removal in vivo. Herein, we presented a nanoformulation of poly-l-lysine-indocyanine green-hyaluronic acid (PIH) and demonstrated that it can image orthodox endometriosis (EM) lesions with a negative contrast. The PIH nanocluster, with an average diameter of approximately 200 nm, exhibited improved fluorescence photostability and antioxidant ability compared to free ICG. In the in vivo imaging, EM lesions were visualized, featuring apparent voids and clear boundaries. After colocalizing with the green fluorescent protein, we concluded that the contrast provided by PIH peaked at 4 h postinjection and was observable for at least 8 h. The negative contrast, clear boundaries, and enhanced observable time might be due to the low permeation of PIH to lesions and the enhanced retention on the surfaces of lesions. Thus, our findings suggest an ICG-based nanoprobe with the potential to diagnose abdominal diseases.

Nanotechnology-Based Drug Delivery Systems in the Transdermal Treatment of Melanoma

The incidence rate of melanoma is dramatically increasing worldwide, raising it to the fifth most common cancer in men and the sixth in women currently. Resistance generally occurs to the agents used in chemotherapy; besides their high toxicity destroys the normal cells. This study reviewed a detailed summary of the structure, advantages, and disadvantages of nanotechnology-based drug delivery systems in the treatment of melanoma, as well as some nanocarrier applications in animal models or clinical studies. Respective databases were searched for the target keywords and 93 articles were reviewed and discussed. A close study of the liposomes, niosomes, transferosomes, ethosomes, transethosomes, cubosomes, dendrimers, cyclodextrins, solid lipid nanoparticles, and carbon nanotubes (CNTs) was conducted. It was found that these nanocarriers could inhibit metastasis and migration of melanoma cells and decrease cell viability. Conclusively, some nanocarriers like liposomes, niosomes, and transferosomes have been discussed as superior to conventional therapies for melanoma treatment.

Polydopamine-containing nano-systems for cancer multi-mode diagnoses and therapies: A review

Polydopamine (PDA) has fascinating properties such as inherent biocompatibility, simple preparation, strong near-infrared absorption, high photothermal conversion efficiency, and strong metal ion chelation, which have catalyzed extensive research in PDA-containing multifunctional nano-systems particularly for biomedical applications. Thus, it is imperative to overview synthetic strategies of various PDA-containing nanoparticles (NPs) for state-of-the-art cancer multi-mode diagnoses and therapies applications, and offer a timely and comprehensive summary. In this review, we will focus on the synthetic approaches of PDA NPs, and summarize the construction strategies of PDA-containing NPs with different structure forms. Additionally, the application of PDA-containing NPs in bioimaging such as photoacoustic imaging, fluorescence imaging, magnetic resonance imaging and other imaging modalities will be reviewed. We will especially offer an overview of their therapeutic applications in tumor chemotherapy, photothermal therapy, photodynamic therapy, photocatalytic therapy, sonodynamic therapy, radionuclide therapy, gene therapy, immunotherapy and combination therapy. At the end, the current trends, limitations and future prospects of PDA-containing nano-systems will be discussed. This review aims to provide guidelines for new scientists in the field of how to design PDA-containing NPs and what has been achieved in this area, while offering comprehensive insights into the potential of PDA-containing nano-systems used in cancer diagnosis and treatment.

Functionalized Magnetic Nanoparticles for NIR-Induced Photothermal Therapy of Potential Application in Cervical Cancer

Photothermal therapy (PTT) holds great promise for cancer treatment with its effective ablation of solid tumors. As the essential core point, photothermal agents (PTAs) with excellent photothermal properties and good biocompatibility could help to fulfill highly efficient PTT. Herein, a novel type of nanoplatform Fe₃O₄@PDA/ICG (FPI) nanoparticle (NP) was designed and synthesized, which was composed of magnetic Fe₃O₄ and near-infrared excitable indocyanine green via encapsulation of polydopamine. The FPI NPs showed spherical structures in shape with uniform distribution and good chemical stability. Under 793 nm laser irradiation, FPI NPs could generate hyperthermia of 54.1 °C and photothermal conversion efficiency of 35.21%. The low cytotoxicity of FPI NPs was further evaluated and confirmed on HeLa cells with a high survival rate (90%). Moreover, under laser irradiation (793 nm), FPI NPs showed effective photothermal therapeutic characteristics for HeLa cells. Therefore, FPI NPs, as one of the promising PTAs, have great potential in the field of PTT for tumor treatment.

A carrier-free nano-drug assembled via π-π stacking interaction for the treatment of osteoarthritis

Osteoarthritis (OA) is considered to be the most common joint disorder. Exogenous drug intervention is one of the effective means for OA treatment. Clinical applications of numerous drugs are restricted owing to the short retention as well as rapid clearance in the joint cavity. A wide variety of carrier-based nanodrugs have been developed, but additional carriers may bring unexpected side effects or even toxicity. Herein, by exploiting the spontaneous fluorescence of Curcumin, we designed a new carrier-free self-assembly nanomedicine Curcumin (Cur)/icariin (ICA) nanoparticles with adjustable particle size, which is composed of two small-molecule natural drugs assembled via π-π stacking interaction. Experimental results revealed that Cur/ICA NPs endowed with little cytotoxicity, high cellular uptake and sustained drug release, could inhibit secretion of inflammatory cytokines and reduce cartilage degeneration. Moreover, both the in vitro and in vivo experiments showed the NPs exerted superior synergism effects in anti-inflammatory and cartilage protection than either Cur or ICA alone, and self-monitored its retention by autofluorescence. Thus, the new self-assembly nano-drug combining Cur and ICA represents a new strategy for the treatment of osteoarthritis.

Polydopamine nanomotors loaded indocyanine green and ferric ion for photothermal and photodynamic synergistic therapy of tumor

The limited penetration depth of nanodrugs in the tumor and the severe hypoxia inside the tumor significantly reduce the efficacy of photothermal-photodynamic synergistic therapy (PTT-PDT). Here, we synthesized a methoxypolyethylene glycol amine (mPEG-NH₂)-modified walnut-shaped polydopamine nanomotor (PDA-PEG) driven by near-infrared light (NIR). At the same time, it also loaded the photosensitizer indocyanine green (ICG) via electrostatic/hydrophobicinteractions and chelated with ferric ion (Fe³⁺). Under the irradiation of NIR, the asymmetry of PDA-PEG morphology led to the asymmetry of local photothermal effects and the formation of thermal gradient, which can make the nanomotor move autonomously. This ability of autonomous movement was proved to be used to improve the permeability of the nanomotor in three-dimensional (3D) tumor sphere. Fe³⁺ can catalyze endogenous hydrogen peroxide to produce oxygen, so as to overcome the hypoxia of tumor microenvironment and thereby generate more singlet oxygen to kill tumor cells. Animal experiments in vivo confirmed that the nanomotors had a good PTT-PDT synergistic treatment effect. The introduction of nanomotor technology has brought new ideas for cancer optical therapy.

Nanoarchitectonics of Indocyanine Green/Doxorubicin-Loaded Hydroxyl Boron Nitride Nanosheets for Chemophotothermal Therapy

Biocompatible hydroxylated boron nitride nanosheets were effectively loaded with indocyanine green and doxorubicin using successive assembly. The indocyanine green/doxorubicin-loaded hydroxyl boron nitride nanosheets (ICG/DOX@OH-BNNS) integrated photothermal therapy and chemotherapy into a single nano vehicle. It had been confirmed that ICG/DOX@OH-BNNS could produce reactive oxygen species and exhibit excellent photothermal effects and light-triggered faster DOX release with NIR laser irradiation. On the other hand, the fluorescence of DOX in ICG/DOX@OH-BNNS was also used for visualizing subcellular location. Compared with individual chemotherapy and photothermal therapy, the combined treatment of ICG/DOX@OH-BNNS could synergistically induce the apoptosis and death of A549 cells and suppress S180 tumor growth in vivo.

PDA-Based Drug Delivery Nanosystems: A Potential Approach for Glioma Treatment

Glioma is characterized by high mortality and low postoperative survival. Despite the availability of various therapeutic approaches and molecular typing, the treatment failure rate and the recurrence rate of glioma remain high. Given the limitations of existing therapeutic tools, nanotechnology has emerged as an alternative treatment option. Nanoparticles, such as polydopamine (PDA)-based nanoparticles, are embodied with reliable biodegradability, efficient drug loading rate, relatively low toxicity, considerable biocompatibility, excellent adhesion properties, precisely targeted delivery, and strong photothermal conversion properties. Therefore, they can further enhance the therapeutic effects in patients with glioma. Moreover, polydopamine contains pyrocatechol, amino and carboxyl groups, active double bonds, catechol, and other reactive groups that can react with biofunctional molecules containing amino, aldehyde, or sulfhydryl groups (main including, self-polymerization, non-covalent self-assembly, π-π stacking, electrostatic attraction interaction, chelation, coating and covalent co-assembly), which form a reversible dynamic covalent Schiff base bond that is extremely sensitive to pH values. Meanwhile, PDA has excellent adhesion capability that can be further functionally modified. Consequently, the aim of this review is to summarize the application of PDA-based NPs in glioma and to acquire insight into the therapeutic effect of the drug-loaded PDA-based nanocarriers (PDA NPs). A wealthy understanding and argument of these sides is anticipated to afford a better approach to develop more reasonable and valid PDA-based cancer nano-drug delivery systems. Finally, we discuss the expectation for the prospective application of PDA in this sphere and some individual viewpoints.

Bacteria Wear ICG Clothes for Rapid Detection of Intracranial Infection in Patients After Neurosurgery and Photothermal Antibacterial Therapy Against Streptococcus Mutans

Bacterial infection is one of the most serious physiological conditions threatening human health. There is an increasing demand for more effective bacterial diagnosis and treatment through non-invasive approaches. Among current antibacterial strategies of non-invasive approaches, photothermal antibacterial therapy (PTAT) has pronounced advantages with properties of minor damage to normal tissue and little chance to trigger antimicrobial resistance. Therefore, we developed a fast and simple strategy that integrated the sensitive detection and photothermal therapy of bacteria by measuring adenosine triphosphate (ATP) bioluminescence following targeted photothermal lysis. First, 3-azido-d-alanine (d-AzAla) is selectively integrated into the cell walls of bacteria, photosensitizer dibenzocyclooctyne, and double sulfonic acid-modified indocyanine green (sulfo-DBCO-ICG) are subsequently designed to react with the modified bacteria through in vivo click chemistry. Next, the sulfo-DBCO-ICG modified bacteria under irradiation of 808 nm near-infrared laser was immediately detected by ATP bioluminescence following targeted photothermal lysis and even the number of bacteria on the infected tissue can be significantly reduced through PTAT. This method has demonstrated the ability to detect the presence of the bacteria for ATP value in 32 clinical samples. As a result, the ATP value over of 100 confirmed the presence of bacteria in clinical samples for 22 patients undergoing craniotomy and ten otitis media patients. Overall, this study paves a brand new avenue to facile diagnosis and a treatment platform for clinical bacterial infections.

NIR-activated nanosystems with self-modulated bacteria targeting for enhanced biofilm eradication and caries prevention

The efficacious delivery of antimicrobial drugs to intractable oral biofilms remains a challenge due to inadequate biofilm penetration and lack of pathogen targeting. Herein, we have developed a microenvironment-activated poly(ethylene glycol) (PEG)-sheddable nanoplatform to mediate targeted delivery of drugs into oral biofilms for the efficient prevention of dental caries. The PEGylated nanoplatform with enhanced biofilm penetration is capable of deshielding the PEG layer under slightly acidic conditions in a PEG chain length-dependent manner to re-expose the bacteria-targeting ligands, thereby facilitating targeted codelivery of ciprofloxacin (CIP) and IR780 to the bacteria after accumulation within biofilms. The nanoplatform tends to induce bacterial agglomeration and suffers from degradation in the acidic oral biofilm microenvironment, triggering rapid drug release on demand around bacterial cells. The self-modulating nanoplatform under near-infrared (NIR) irradiation accordingly displays greatly augmented potency in oral biofilm penetration and disruption compared with drugs alone. Topical oral treatment with nanoplatforms involving synergetic pharmacological and photothermal/photodynamic trinary therapy results in robust biofilm dispersion and efficacious suppression of severe tooth decay in rats. This versatile nanoplatform can promote local accumulation and specific drug transport into biofilms and represents a new paradigm for targeted drug delivery for the management of oral biofilm-associated infections.

•

A targeted drug delivery system was developed to scavenge oral biofilms and prevent dental caries.

•

The system is activated by pH gradient to modulate biofilm penetration, bacterial anchorage and drug release.

•

The system demonstrated significant efficacy in preventing dental caries under a multimodal treatment regimen.

•

This strategy is expected to be applied to control a range of oral biofilm-associated infections.

Nanodiamond-based multifunctional platform for oral chemo-photothermal combinational therapy of orthotopic colon cancer

Combination therapy system has become a promising strategy for achieving favorable antitumor efficacy. Herein, a novel oral drug delivery system with colon localization and tumor targeting functions was designed for orthotopic colon cancer chemotherapy and photothermal combinational therapy. The polydopamine coated nanodiamond (PND) was used as the photothermal carrier, through the coupling of sulfhydryl-polyethylene glycol-folate (SH-PEG-FA) on the surface of PND to achieve systematic colon tumor targeting, curcumin (CUR) was loaded as the model drug, and then coated with chitosan (CS) to achieve the long gastrointestinal tract retention and colon localization functions to obtain PND-PEG-FA/CUR@CS nanoparticles. It has high photothermal conversion efficiency and good photothermal stability and exhibited near-infrared (NIR) laser-responsive drug release behavior. Folate (FA) modification effectively promotes the intracellular uptake of nanoparticles by CT26 cells, and the combination of chemotherapy and photothermal therapy (CT/PTT) can enhance cytotoxicity. Compared with free CUR group, nanoparticles prolonged the gastrointestinal tract retention time, accumulated more in colon tumor tissues, and exhibited good photothermal effect in vivo. More importantly, the CT/PTT group exhibited satisfactory tumor growth inhibition effects with good biocompatibility in vivo. In summary, this oral drug delivery system is an efficient platform for chemotherapy and photothermal combinational therapy of orthotopic colon cancer.

A Virus-like-inspired Nanoparticles Facilitates Bacterial Internalization for Enhanced Eradication of Drug-resistant Pathogen

The emergence and rapid spread of bacterial resistance pose an extremely serious threat to treat infections. Inspired that the spiny surface structure of virus plays an important role in mediating...

Engineered Exosomes-Based Photothermal Therapy with MRI/CT Imaging Guidance Enhances Anticancer Efficacy through Deep Tumor Nucleus Penetration

Exosomes, as natural nanovesicles, have become a spotlight in the field of cancer therapy due to their reduced immunogenicity and ability to overcome physiological barriers. However, the tumor targeting ability of exosomes needs to be improved before its actual application. Herein, a multiple targeted engineered exosomes nanoplatform was constructed through rare earth element Gd and Dy-doped and TAT peptide-modified carbon dots (CDs:Gd,Dy-TAT) encapsulated into RGD peptide engineered exosomes (Exo-RGD), which were used to enhance the effect of cancer imaging diagnosis and photothermal therapy. In vitro and in vivo experiments showed that the resulting CDs:Gd,Dy-TAT@Exo-RGD could effectively accumulate at cancer site with an increased concentration owing to the targeting peptides modification and exosomes encapsulation. The tumor therapy effects of mice treated with CDs:Gd,Dy-TAT@Exo-RGD were heightened compared with mice from the CDs:Gd,Dy control group. After intravenous injection of CDs:Gd,Dy-TAT@Exo-RGD into tumor-bearing mice, the temperature of tumors rose to above 50 °C under NIR irradiation and the localized hyperpyrexia induced by CDs could remarkably ablate tumors. The survival rate of the mice was 100% after 60 days. In addition, the CDs:Gd,Dy-TAT@Exo-RGD exhibited higher MRI/CT imaging contrast enhancement of tumor sites than that of CDs:Gd,Dy. Our study identified that engineered exosomes are a powerful tool for encapsulating multiple agents to enhance cancer theranostic efficiency and provide insight into precise personalized nanomedicine.

A diselenide bond-containing ROS-responsive ruthenium nanoplatform delivers nerve growth factor for Alzheimer's disease management by repairing and promoting neuron regeneration

Alzheimer's disease (AD) is an incurable neurodegenerative disease. Repairing damaged nerves and promoting nerve regeneration are key ways to relieve AD symptoms. However, due to the lack of effective strategies to deliver nerve growth factor (NGF) to the brain, achieving neuron regeneration is a major challenge for curing AD. Herein, a ROS-responsive ruthenium nanoplatform (R@NGF-Se-Se-Ru) drug delivery system for AD management by promoting neuron regeneration and Aβ clearance was investigated. Under near-infrared (NIR) irradiation, nanoclusters have good photothermal properties, which can effectively inhibit the aggregation of Aβ and disaggregate Aβ fibrils. Interestingly, the diselenide bond in the nanoclusters is broken, and the nanoclusters are degraded into small ruthenium nanoparticles in the high reactive oxygen species (ROS) environment of the diseased area. Besides, NGF can promote neuronal regeneration and repair damaged nerves. Furthermore, R@NGF-Se-Se-Ru efficiently crosses the blood-brain barrier (BBB) owing to the covalently grafted target peptides of RVG (R). In vivo studies demonstrate that R@NGF-Se-Se-Ru nanoclusters decrease Aβ deposits, inhibit Aβ-induced cytotoxicity, and promote neurite outgrowth. The study confirms that promoting both Aβ clearance and neuron regeneration is an important therapeutic target for anti-AD drugs and provides a novel insight for AD therapy.

Comparative Toxicity, Biodistribution and Excretion of Ultra-Small Gold Nanoclusters with Different Emission Wavelengths

The exponentially increased use of gold nanoclusters in diagnosis and treatment has raised serious concern about their potential threat to living organisms. However, the mechanisms of toxicity of gold nanoclusters in vitro and in vivo remain poorly understood. In this work, comparative toxicity studies, including biodistribution and excretion, were carried out with mildly and chemically synthesized ultra-small L-histidine-protected and bovine serum albumin (BSA)-protected gold nanoclusters in an all-aqueous process. These nanoclusters did not induce a remarkable impact on cell viability, even at relatively high concentrations (100 μg/mL). The haemolytic assay demonstrated that the gold nanoclusters could not destroy blood cell at 600 μg/mL. After intravenous injection with mice, the biocompatibility, biodistribution, and excretion were determined. Quantitative analysis results showed that accumulation varied in the liver, spleen, kidney, and lung, though primarily in the liver and spleen. They were excreted in urine and faeces, but mainly excreted through urine. In our study, no obvious abnormalities were found in body weight, behavioral changes, blood and serum biochemical indicators, and histopathology. These findings suggested that both gold nanoclusters showed similar effects in vivo and were safe and biocompatible, laying the foundation for safe biomedical application in the future.

Efficacy, biocompatibility and degradability of carbon nanoparticles for photothermal therapy of lung cancer

Aim: To investigate near infrared-induced phototoxicity toward lung cancer cells, and the biodegradability and effect on immune cells of glucose-derived carbon nanoparticles (CNPs). Methods: The human A549 lung adenocarcinoma cell line was used as a model to study the phototoxicity of CNPs. The biodegradability and the effect on immune cells was demonstrated in primary human neutrophils and macrophages. Results: Near infrared-activated CNPs elicited rapid cell death, characterized by the elevation of heat shock proteins and the induction of DNA damage. CNPs were found to be noncytotoxic toward primary human macrophages and were susceptible to biodegradation when cocultured with human neutrophils. Conclusions: Our results identify CNPs as promising platforms for photothermal therapy of lung cancer.

Phenolic-enabled nanotechnology: versatile particle engineering for biomedicine

Phenolics are ubiquitous in nature and have gained immense research attention because of their unique physiochemical properties and widespread industrial use. In recent decades, their accessibility, versatile reactivity, and relative biocompatibility have catalysed research in phenolic-enabled nanotechnology (PEN) particularly for biomedical applications which have been a major benefactor of this emergence, as largely demonstrated by polydopamine and polyphenols. Therefore, it is imperative to overveiw the fundamental mechanisms and synthetic strategies of PEN for state-of-the-art biomedical applications and provide a timely and comprehensive summary. In this review, we will focus on the principles and strategies involved in PEN and summarize the use of the PEN synthetic toolkit for particle engineering and the bottom-up synthesis of nanohybrid materials. Specifically, we will discuss the attractive forces between phenolics and complementary structural motifs in confined particle systems to synthesize high-quality products with controllable size, shape, composition, as well as surface chemistry and function. Additionally, phenolic's numerous applications in biosensing, bioimaging, and disease treatment will be highlighted. This review aims to provide guidelines for new scientists in the field and serve as an up-to-date compilation of what has been achieved in this area, while offering expert perspectives on PEN's use in translational research.

Polydopamine-Based Nanoparticles for Photothermal Therapy/Chemotherapy and their Synergistic Therapy with Autophagy Inhibitor to Promote Antitumor Treatment

Polydopamine (PDA) has attracted much attention recently due to its strong adhesion capability to most substrates. After combining with organic (such as organic metal framework, micelles, hydrogel, polypeptide copolymer) or inorganic nanomaterials (such as gold, silicon, carbon), polydopamine-based nanoparticles (PDA NPs) exhibit the merging of characteristics. Until now, the preparation methods, polymerization mechanism, and photothermal therapy (PTT) or chemotherapy (CT) applications of PDA NPs have been reported detailly. Since the PTT or CT treatment process is often accompanied by exogenous stimuli, tumor cells usually induce pro-survival autophagy to protect the cells from further damage, which will weaken the therapeutic effect. Therefore, an in-depth understanding of PDA NPs modulated PTT, CT, and autophagy is required. However, this association is rarely reviewed. Herein, we briefly described the relationship between PTT/CT, autophagy, and tumor treatment. Then, the outstanding performances of PDA NPs in PTT/CT and their combination with autophagy inhibitors for tumor synergistic therapy have been summarized. This work is expected to shed light on the multi-strategy antitumor therapy applications of PDA NPs.

Nanocarrier-Based Drug Delivery for Melanoma Therapeutics

Melanoma, as a tumor cell derived from melanocyte transformation, has the characteristics of malignant proliferation, high metastasis, rapid recurrence, and a low survival rate. Traditional therapy has many shortcomings, including drug side effects and poor patient compliance, and so on. Therefore, the development of an effective treatment is necessary. Currently, nanotechnologies are a promising oncology treatment strategy because of their ability to effectively deliver drugs and other bioactive molecules to targeted tissues with low toxicity, thereby improving the clinical efficacy of cancer therapy. In this review, the application of nanotechnology in the treatment of melanoma is reviewed and discussed. First, the pathogenesis and molecular targets of melanoma are elucidated, and the current clinical treatment strategies and deficiencies of melanoma are then introduced. Following this, we discuss the main features of developing efficient nanosystems and introduce the latest reports in the literature on nanoparticles for the treatment of melanoma. Subsequently, we review and discuss the application of nanoparticles in chemotherapeutic agents, immunotherapy, mRNA vaccines, and photothermal therapy, as well as the potential of nanotechnology in the early diagnosis of melanoma.

Ligand-Targeted Delivery of Photosensitizers for Cancer Treatment

Photodynamic therapy (PDT) is a promising cancer treatment which involves a photosensitizer (PS), light at a specific wavelength for PS activation and oxygen, which combine to elicit cell death. While the illumination required to activate a PS imparts a certain amount of selectivity to PDT treatments, poor tumor accumulation and cell internalization are still inherent properties of most intravenously administered PSs. As a result, common consequences of PDT include skin photosensitivity. To overcome the mentioned issues, PSs may be tailored to specifically target overexpressed biomarkers of tumors. This active targeting can be achieved by direct conjugation of the PS to a ligand with enhanced affinity for a target overexpressed on cancer cells and/or other cells of the tumor microenvironment. Alternatively, PSs may be incorporated into ligand-targeted nanocarriers, which may also encompass multi-functionalities, including diagnosis and therapy. In this review, we highlight the major advances in active targeting of PSs, either by means of ligand-derived bioconjugates or by exploiting ligand-targeting nanocarriers.

Polydopamine-based nanoreactors: synthesis and applications in bioscience and energy materials

Polydopamine (PDA)-based nanoreactors have shown exceptional promise as multifunctional materials due to their nanoscale dimensions and sub-microliter volumes for reactions of different systems. Biocompatibility, abundance of active sites, and excellent photothermal conversion have facilitated their extensive use in bioscience and energy storage/conversion. This minireview summarizes recent advances in PDA-based nanoreactors, as applied to the abovementioned fields. We first highlight the design and synthesis of functional PDA-based nanoreactors with structural and compositional diversity. Special emphasis in bioscience has been given to drug/protein delivery, photothermal therapy, and antibacterial properties, while for energy-related applications, the focus is on electrochemical energy storage, catalysis, and solar energy harvesting. In addition, perspectives on pressing challenges and future research opportunities regarding PDA-based nanoreactors are discussed.

Activatable Phototheranostic Materials for Imaging-Guided Cancer Therapy

Cancer theranostics, which combines diagnostic and therapeutic effects into one entity, holds promise in precision medicine. Conventional theranostic agents possess always-on imaging signals and cytotoxic effects and thus often encounter poor selectivity or specificity in cancer treatment. To tackle this issue, activatable phototheranostic materials (PMs) have been developed to simultaneously and specifically turn on their diagnostic signals (fluorescence/self-luminescence/photoacoustic signals) and photothermal/photodynamic effects in response to cancer hallmarks. This Review summarizes the recent progress in the design, synthesis and proof-of-concept applications of activatable PMs. The molecular engineering strategy to increase tumor accumulation and enhance treatment efficacy are highlighted. Current challenges and future perspectives in this emerging field are also discussed.

Nanoparticle-based drug delivery systems for controllable photodynamic cancer therapy

Compared with the traditional treatment, photodynamic therapy (PDT) in the treatment of malignant tumors has the advantages of less damage to normal tissues, quick therapeutic effect, and ability to repeat treatments to the same site. However, most of the traditional photosensitizers (PSs) have severe skin photosensitization, poor tumor targeting, and low therapeutic effect in hypoxic tumor environment, which limit the application of PDT. Nanoparticle-based drug delivery systems can improve the targeting of PSs and release drugs with controllable photoactivity at predetermined locations, so as to achieve desired therapeutic effects with minimal side-effects. The present review summarizes the current nanoparticle platforms for PDT, and offers the description of different strategies including tumor-targeted delivery, controlled-release of PSs and the triggered photoactivity to achieve controllable PDT by nanoparticle-based drug delivery systems. The challenges and prospects for further development of intelligent PSs for PDT are also discussed.

Bioinspired Heteromultivalent Ligand-Decorated Nanotherapeutic for Enhanced Photothermal and Photodynamic Therapy of Antibiotic-Resistant Bacterial Pneumonia

Pseudomonas aeruginosa can cause a multitude of inflammations in humans. Due to its ability to form biofilm, the bacteria show durable resistance to drugs. Herein, we developed a heteromultivalent ligand-decorated nanotherapeutic inspired by living system for inhibition of antibiotic-resistant bacterial pneumonia. The nanotherapeutic with a heteromultivalent glycomimetic shell can specifically recognize P. aeruginosa to inhibit its biofilm formation and protect native cells from bacterial infection; the rate of biofilm inhibition was up to 85%. The nanotherapeutic with a bioresponsive hydrophobic core can protonate and control drug release in the microenvironment of bacterial infections. By utilizing these properties, the nanotherapeutics can effectively penetrate the internal structure of biofilms to release the drug, dispersing the biofilm by over 80% under laser irradiation. In vivo bioinspired nanotherapeutics have the potential to efficiently inhibit antibiotic-resistant P. aeruginosa-induced pneumonia. Collectively, we expect biomimicking systems to be the next generation of prevention and treatment as integrated antibacterial agents against P. aeruginosa.

A Dual-Model Imaging Theragnostic System Based on Mesoporous Silica Nanoparticles for Enhanced Cancer Phototherapy

Mesoporous silica nanoparticles (MSNs) show great promise to be exploited as versatile multifunctional nanocarriers for effective cancer diagnosis and treatment. In this work, perfluorohexane (PFH)-encapsulated MSNs with indocyanine green (ICG)-polydopamine (PDA) layer and poly(ethylene glycol)-folic acid coating (designated as MSNs-PFH@PDA-ICG-PEG-FA) are successfully fabricated to achieve tumor ultrasonic (US)/near-infrared fluorescence (NIRF) imaging as well as photothermal therapy (PTT)/photodynamic therapy (PDT). MSNs-PFH@PDA-ICG-PEG-FA exhibits good monodispersity with high ICG loading, significantly enhances ICG photostability, and greatly improves cellular uptake. Upon single 808 nm NIR irradiation, the nanocarrier not only efficiently generates hyperthermia to realize PTT, but also produces reactive oxygen species (ROS) for effective PDT. Meanwhile, NIR irradiation can trigger PFH to undergo vaporization and provide a super-resolution US image. Thus, the PTT/PDT combination therapy can be dually guided by PFH-induced US imaging and ICG-induced NIRF imaging. In vivo antitumor studies demonstrate that PTT/PDT from MSNs-PFH@PDA-ICG-PEG-FA significantly inhibits tumor growth and achieves a cure rate of 60% (three out of five mice are completely cured). Hence, the multifunctional MSNs appear to be a promising theragnostic nanoplatform for multimodal cancer imaging and therapy.

Cartilage-targeting and dual MMP-13/pH responsive theranostic nanoprobes for osteoarthritis imaging and precision therapy

Osteoarthritis (OA) microenvironment is marked by matrix metalloproteinases-13 (MMP-13) overexpression and weak acidity, making it possible to develop dual-stimuli responsive theranostic nanoprobes for OA diagnosis and therapy. However, current MMP/pH-responsive systems are not suitable for OA because of their poor biocompatibility, poor degradation and non-cartilage-targeting of the responsive probes. Here we designed a novel biocompatible cartilage-targeting and MMP-13/pH-responsive ferritin nanocages (CMFn) loaded with an anti-inflammatory drug (Hydroxychloroquine, HCQ), termed CMFn@HCQ, for OA imaging and therapy. We found that CMFn could be smartly "turned on" to emit light for OA imaging in response to the level of overexpressed MMP-13 in OA microenvironment, corresponding to the degree of OA severity. Thus the light intensity detected reflected the degree of OA severity, enabling the precise disease classification by our CMFn. CMFn could be "turned off" to stop emitting light in the normal joint. CMFn@HCQ nanocages could target the cartilage and release HCQ in the OA joint specifically under acidic pH conditions in a sustained manner, prolonging the drug retention time to 14 days to remarkably reduce synovial inflammation in the OA joints. The CMFn@HCQ nanocages represent a smart dual-stimuli responsive and cartilage-targeting nanoprobes, and hold promise for imaging-guided precision therapy for OA.

Versatile Polydopamine Platforms: Synthesis and Promising Applications for Surface Modification and Advanced Nanomedicine

As a mussel-inspired material, polydopamine (PDA), possesses many properties, such as a simple preparation process, good biocompatibility, strong adhesive property, easy functionalization, outstanding photothermal conversion efficiency, and strong quenching effect. PDA has attracted increasingly considerable attention because it provides a simple and versatile approach to functionalize material surfaces for obtaining a variety of multifunctional nanomaterials. In this review, recent significant research developments of PDA including its synthesis and polymerization mechanism, physicochemical properties, different nano/microstructures, and diverse applications are summarized and discussed. For the sections of its applications in surface modification and biomedicine, we mainly highlight the achievements in the past few years (2016-2019). The remaining challenges and future perspectives of PDA-based nanoplatforms are discussed rationally at the end. This timely and overall review should be desirable for a wide range of scientists and facilitate further development of surface coating methods and the production of PDA-based materials.

Functionalized theranostic nanocarriers with bio-inspired polydopamine for tumor imaging and chemo-photothermal therapy

Nanocarriers sensitive to near infrared light (NIR) are useful templates for chemo-photothermal therapy (PTT) and imaging of tumors due to the ability to change the absorbed NIR energy to heat. The conventional photo-absorbing reagents lack the efficient loading and release of drug before reaching the target site leading to insufficient therapeutic outcomes. To overcome these limitations, the surface of nanocarriers can be modified with different polymers with wide functionalities to provide systems with diagnostic, therapeutic, and theranostic capabilities. Among various polymers, polydopamine (PDA) has been more interested due to complex structure with various chemical moieties, and the capacity to be used through different coating mechanism. In this review, we describe the complex structure, chemical properties, and coating mechanisms of PDA. Moreover, the advantage and surface modification of some relevant nanosystems based on carbon materials, gold, iron oxide, manganese, and upconverting nanomaterials by using PDA will be discussed, in detail.

Gold nanorods functionalized by a glutathione response near-infrared fluorescent probe as a promising nanoplatform for fluorescence imaging guided precision therapy

Theranostics nanoplatforms offer opportunities for imaging-guided precision therapy and hold great potential for clinical applications. In most reported works, the imaging unit has a lack of site selectivity, and is always kept in the "on" modality regardless of whether it is in normal tissues or tumor sites, increasing the risk of unsafe treatment. Herein, we designed a near-infrared (NIR) fluorescence-guided theranostics nanoplatform by integrating the functions of tumor-response and photodynamic therapy (PDT)/photothermal therapy (PTT). A novel NIR fluorescent dye, CyPT, with excellent optical and PDT/PTT properties, was synthesized and linked onto the gold nanorods (AuNRs) to form CyPT-AuNRs nanohybrids via a sulfur-sulfur bond that can be broken by glutathione (GSH) with high selectivity and sensitivity. In normal cells where the concentration of GSH is low, the fluorescence of CyPT is quenched by the AuNRs. By contrast, the high level of GSH in tumor cells leads to the breaking of the sulfur-sulfur bond, resulting in the release of CyPT and the accomplishment of a "off-on" fluorescence response. Followed by precise NIR tumor-imaging diagnosis, the PDT and PTT treatment which rely on the released CyPT and AuNRs, respectively, can be effectively performed. The CyPT-AuNRs nanoplatform has been successfully applied to the treatment of tumor xenograft models and no distinct damage has been observed in the nearby normal tissues. This versatile nanoplatform has potential for use in targeted tumor imaging and precision therapy.

Dopamine-Mediated Assembly of Citrate-Capped Plasmonic Nanoparticles into Stable Core-Shell Nanoworms for Intracellular Applications

Plasmonic nanochains, derived from the one-dimensional assembly of individual plasmonic nanoparticles (NPs), remain infrequently explored in biological investigations due to their limited colloidal stability, ineffective cellular uptake, and susceptibility to intracellular disassembly. We report the synthesis of polydopamine (PDA)-coated plasmonic "nanoworms" (NWs) by sonicating citrate-capped gold (Cit-Au) NPs in a concentrated dopamine (DA) solution under alkaline conditions. DA mediates the assembly of Cit-Au NPs into Au NWs within 1 min, and subsequent self-polymerization of DA for 60 min enables the growth of an outer conformal PDA shell that imparts stability to the inner Au NW structure in solution, yielding "core-shell" Au@PDA NWs with predominantly 4-5 Au cores per worm. Our method supports the preparation of monometallic Au@PDA NWs with different core sizes and bimetallic PDA-coated NWs with Au and silver cores. The protonated primary amine and catechol groups of DA, with their ability to interact with Cit anions via hydrogen bonding and electrostatic attraction, are critical to assembly. When compared to unassembled PDA-coated Au NPs, our Au@PDA NWs scatter visible light and absorb near-infrared light more intensely and enter HeLa cancer cells more abundantly. Au@PDA NWs cross the cell membrane as intact entities primarily via macropinocytosis, mostly retain their inner NW structure and outer PDA shell inside the cell for 24 h, and do not induce noticeable cytotoxicity. We showcase three intracellular applications of Au@PDA NWs, including label-free dark-field scattering cell imaging, delivery of water-insoluble cargos without pronounced localization in acidic compartments, and photothermal killing of cancer cells.

Tumor-Activatable Clinical Nanoprobe for Cancer Imaging

Purpose: A successful cancer surgery requires the complete removal of cancerous tissue, while also sparing as much healthy, non-cancerous tissue as possible. To achieve this, an accurate identification of tumor boundaries during surgery is critical, but intra-operative tumor visualization remains challenging. Fluorescence imaging is a promising method to improve tumor detection and delineate tumor boundaries during surgery, but the lack of stable, long-circulating, clinically-translatable fluorescent probes that can identify tumors with high signal-to-noise ratios and low background fluorescence signals have prevented its widespread application. Methods: We screened the optical properties of several fluorescent dyes before and after nanoprobe encapsulation, and then identified nanoprobes with quenched fluorescence that were re-activated upon dye release. The physical and biological properties of these nanoprobes leading to fluorescence activation were investigated in vitro. Further, the cancer imaging properties of both free dyes and nanoprobe-encapsulated dyes were compared in vivo. Results: A novel fluorescent nanoprobe was prepared by combining two FDA-approved agents commonly used in the clinic: Feraheme (FH) and indocyanine green (ICG). The resulting FH-entrapped ICG nanoprobe [FH(ICG)] displayed quenched fluorescence compared to other nanoprobes, and this quenched fluorescence was re-activated in acidic tumor microenvironment conditions (pH 6.8) and upon uptake into cancer cells. Finally, in vivo studies in a prostate cancer mouse model demonstrated that FH(ICG) treatments enhance long-term fluorescence signals in tumors compared to ICG treatments, allowing for fluorescence-guided tumor identification using clinically relevant fluorescence cameras. Conclusions: FH(ICG) nanoprobes were identified as fluorescent nanoprobes with beneficial fluorescence activation properties compared to other FH-entrapped dyes. The activatable nature of this nanoprobe allows for a low background fluorescence signal and high signal-to-noise ratio within a long-circulating nanoagent, which allows for long-term fluorescence signals from tumors that enabled their fluorescence-guided detection. This activatable nanoprobe offers tremendous potential as a clinically translatable image-guided cancer therapy modality that can be prepared in a clinical setting.

Pro- and anti-oxidant properties of near-infrared (NIR) light responsive carbon nanoparticles

Elemental carbon nanomaterials (ECNMs) are redox active agents that can be exploited to purposely modify the redox balance of cells. Both pro- or antioxidant properties have been reported. However, to the best of our knowledge, there are not comprehensive studies exploring both properties on the same material in view of a potential application in medicine. At the same time, the effect of the bulk structure on the pro/antioxidant properties is poorly known. Here, carbon nanoparticles (CNPs) derived by glucose with definite size and shape have been prepared, and their redox properties evaluated in cell free systems in the dark or following activation with a Near Infrared (NIR) laser beam (945 nm, 1.3 W/cm²). We found that, when irradiated with NIR, CNPs efficiently generate heat and singlet oxygen (¹O₂), a property that can be exploited for dual photo-thermal (PT)/photodynamic (PD) therapy in cancer. On the other hand, in the absence of photo-activation, CNPs react with both oxidant (hydroxyl radicals) and antioxidant (glutathione) species. When tested on a murine macrophages cell line (RAW 264.7) CNPs were clearly antioxidant. Furthermore, albeit efficiently internalized, CNPs do not exert cytotoxic effect up to 80 µg/ml and do not exacerbate TNF-α-mediated inflammation. Overall, the results reported herein suggest that CNPs may represent a new class of safe nanomaterials with potential applications in medicine.

Polydopamine-coated Au nanorods for targeted fluorescent cell imaging and photothermal therapy

Au nanorods (AuNRs) have attracted a great interest as a platform for constructing various composite core/shell nanoparticles for theranostics applications. However, the development of robust methods for coating AuNRs with a biocompatible shell of high loading capacity and with functional groups still remains challenging. Here, we coated AuNRs with a polydopamine (PDA) shell and functionalized AuNR-PDA particles with folic acid and rhodamine 123 (R123) to fabricate AuNR-PDA-R123-folate nanocomposites. To the best of our knowledge, such AuNR-PDA-based composites combining fluorescent imaging and plasmonic phothothermal abilities have not been reported previously. The multifunctional nanoparticles were stable in cell buffer, nontoxic and suitable for targeted fluorescent imaging and photothermal therapy of cancer cells. We demonstrate the enhanced accumulation of folate-functionalized nanoparticles in folate-positive HeLa cells in contrast to the folate-negative HEK 293 cells using fluorescent microscopy. The replacement of folic acid with polyethylene glycol (PEG) leads to a decrease in nanoparticle uptake by both folate-positive and folate-negative cells. We performed NIR light-mediated targeted phototherapy using AuNR-PDA-R123-folate and obtained a remarkable cancer cell killing efficiency in vitro in comparison with only weak-efficient nontargeted PEGylated nanoparticles. Our work illustrates that AuNR-PDA could be a promising nanoplatform for multifunctional tumor theranostics in the future.

Polydopamine-coated NaGdF4:Dy for T1/T2-weighted MRI/CT multimodal imaging-guided photothermal therapy

T₁/T₂-weighted MRI/CT imaging-guided PTT agent NaGdF₄:Dy@PPF was prepared and demonstrated its promising application for early diagnosis and therapy of tumors.

Self-quenching synthesis of coordination polymer pre-drug nanoparticles for selective photodynamic therapy

A novel “pre-photodynamic” nanoparticles (Fe-IBDP NPs) with a tumor microenvironment (TME)-activatable PDT and good biodegradability were synthesized by self-quenching strategy.

Hyaluronic Acid Layer-By-Layer (LbL) Nanoparticles for Synergistic Chemo-Phototherapy

PURPOSE

The aim of this study was to design hyaluronic acid (HA) layer-by-layer (LbL) nanoparticles, which carried paclitaxel (PTX) and Indocyanine green (ICG) to both tumor cells and tumor associated cells to achieve synergistic chemo-photothermal therapeutic effect.

METHODS

The LbL-engineered nanoparticles (PDIH) were prepared by dopamine self-polymerization on PTX nanocrystal to form thin, surface-adherent polydopamine (PDA) films, which subsequently absorbed ICG and HA. The tumor cell and tumor associated cell targeting and antitumor efficacy of PDIH were investigated both in vitro an in vivo using 4 T1 murine mammary cancer cell lines and mice bearing orthotopic 4 T1 breast tumor.

RESULTS

PDIH presented a long-rod shape in TEM and showed enhanced photothermal effect and cytotoxicity upon NIR laser irradiation both in vitro and in vivo. PDIH also displayed high target ability to CD44 overexpressed tumor cells and tumor associated cells mediated by HA. In vivo antitumor study indicated that PDIH therapeutic strategy could achieve remarkable antitumor efficacy.

CONCLUSION

PDIH showed excellent tumor-targeting property and chemo-photothermal therapeutic efficacy.

Development of Multifunctional Polydopamine Nanoparticles As a Theranostic Nanoplatform against Cancer Cells

Although demanding, the development of multifunctional theranostic nanoplatforms is attracting considerable worldwide interest. Herein, a theranostic nanoplatform with multifunctions based on polydopamine (PDA) nanoparticles (NPs) was developed, owning dual-imaging and dual-therapy functions for cancer theranostic applications. PDA NPs were generated using a facile polymerization method under alkaline conditions, followed by poly(ethylene glycol) (PEG) modification. Then, the obtained NPs were loaded with IR820 and Fe³⁺ ions to produce the final PEGylated PDA/IR820/Fe³⁺ (PPIF) NPs. The PPIF NPs thus generated displayed increasingly brighter photoacoustic and magnetic resonance signals with increasing NP concentration and were demonstrated to be cytocompatible and effectively taken up and internalized into HeLa cells. Under near-infrared light irradiation, PPIF NPs can produce heat and reactive oxygen species for photothermal/photodynamic combined cancer therapy. In this study, the versatility of PDA NPs was demonstrated to be promising as a multifunctional nanoplatform for potential cancer theranostic applications.

Loading IR820 Using Multifunctional Dendrimers with Enhanced Stability and Specificity

Cyanine dyes are promising candidates in biomedical applications. Although various delivery systems have been developed to enhance their properties, their dendrimer-based delivery systems are seldom investigated. Herein, amine-terminated generation 5 poly(amidoamine) (G5.NH₂) dendrimers and new indocyanine green (IR820) dyes were chosen as models to study the loading ability of dendrimers for cyanine dynes. G5.NH₂ dendrimers were pre-modified with arginine-glycine-aspartic (RGD) peptides, poly(ethylene glycol) chains, and acetyl groups to be endowed with cancer cell specificity and biocompatibility. The formed Ac-PR dendrimers were used to load IR820, followed by thorough characterization. The loaded number of IR820 was estimated to be 6.7 per dendrimer. The stability of IR820 was improved through dendrimer loading, which was proved by their UV-vis spectra under different kinds of storage conditions. In addition, the formed Ac-PR dendrimers can retain the loaded IR820 effectively. Their cytocompatibility was desirable under the studied conditions. Their cellular uptake behaviors were demonstrated to be enhanced by RGD modification, showing concentration-, co-incubation time-, and αvβ₃ integrin receptor-dependent properties, displaying a cytoplasm-location. The findings from this work demonstrated the versatile loading and delivery capacity of dendrimers for near-infrared (NIR) dyes, providing fundamental data for the development of dendrimer/NIR dye systems for biomedical applications, especially for cancer theranostic applications.

Polydopamine Nanoparticles Enhance Drug Release for Combined Photodynamic and Photothermal Therapy

Our study shows a facile two-step method which does not require the use of core templates to load a hydrophobic photosensitizer drug chlorin e6 (Ce6) within polydopamine (PDA) nanoparticles (NPs) while maintaining the intrinsic surface properties of PDA NPs. This structure is significantly different from hollow nanocapsules which are less stiff as they do not possess a core. To our knowledge, there exist no similar studies in the literature on drug loading within the polymer matrix of PDA NPs. We characterized the drug loading and release behavior of the photosensitizer Ce6 and demonstrated the therapeutic efficacy of the combined photodynamic (PDT) and photothermal therapy (PTT) from Ce6 and PDA, respectively, under a single wavelength of 665 nm irradiation on bladder cancer cells. We obtained a saturated loading amount of 14.2 ± 0.85 μM Ce6 in 1 nM PDA NPs by incubating 1 mg/mL dopamine solution with 140 μM of Ce6 for 20 h. The PDA NPs maintained colloidal stability in biological media, whereas the pi-pi (π-π) interaction between PDA and Ce6 enabled a release profile of the photosensitizer until day 5. Interestingly, loading of Ce6 in the polymer matrix of PDA NPs significantly enhanced the cell uptake because of endocytosis. An increased cell kill was observed with the combined PDT + PTT from 1 nM PDA-Ce6 compared to that with PTT alone with 1 nM PDA and PDT alone with 15 μM equivalent concentration of free Ce6. PDA-Ce6 NPs could be a promising PDT/PTT therapeutic agent for cancer therapy.

Yolk-structured multifunctional up-conversion nanoparticles for synergistic photodynamic-sonodynamic antibacterial resistance therapy

The worldwide increase in bacterial antibiotic resistance has led to a search for alternative antibacterial therapies. The present study reports the development of yolk-structured multifunctional up-conversion nanoparticles (UCNPs) that combine photodynamic and sonodynamic therapy for effective killing of antibiotic-resistant bacteria. The multifunctional nanoparticles (NPs) were achieved by enclosing hematoporphyrin monomethyl ether (HMME) into its yolk-structured up-conversion core and covalently linked rose bengal (RB) on its silica (SiO₂) shell. Excitation of UCNPs with near-infrared (NIR) light that has improved penetration depth for photodynamic therapy (PDT) enabled the activation of HMME and RB and thus the generation of singlet oxygen (¹O₂). The SiO₂ layer, which improved the biocompatibility of the UCNPs, surrounded the yolk structure, with a cavity space which had a high efficiency of loading photosensitizers. Synergistic PDT and sonodynamic therapy (SDT) improved the photosensitizer utilization rate. As a result, a greater inhibition rate was observed when antibiotic-resistant bacteria were treated with a combined therapy (100%) compared with either the PDT (74.2%) or SDT (70%) alone. Our data indicate that the multifunctional NPs developed in this study have the potential for use in the clinical synergistic PDT-SDT treatment of infectious diseases caused by antibiotic-resistant bacteria.

Polydopamine-Based Multifunctional (Nano)materials for Cancer Therapy

Since Lee published a pioneering paper about polydopamine (PDA), application of that polymer in a number of areas has grown enormously in the last 10 years and is still growing. PDA's spectacular success can be attributed to its unique features, i.e., simple preparation protocol, strong adhesive properties, easy and straightforward functionalization, and biocompatibility. Therefore, this polymer has attracted the attention of a vast group of scientists, including those working in the field of nanomedicine. In consequence, polydopamine has been merged with various nanostructures that differ in size and nature, which has resulted in novel types of multifunctional nanomaterials that have recently been extensively exploited in nanomedicine and particularly in cancer therapy. The aim of this article is to offer insight into the latest achievements (up until the end of 2016) in the field of synthesis and application of nanomaterials based on polydopamine and their application in cancer therapy. The conclusions regarding the application of polydopamine-based nanoplatforms in this area and future prospects are given at the end.

Recent developments in dopamine-based materials for cancer diagnosis and therapy

Dopamine-based materials are emerging as novel biomaterials and have attracted considerable interests in the fields of biosensing, bioimaging and cancer therapy due to their unique physicochemical properties, such as versatile adhesion property, high chemical reactivity, excellent biocompatibility and biodegradability, strong photothermal conversion capacity, etc. In this review, we present an overview of recent research progress on dopamine-based materials for diagnosis and therapy of cancer. The review starts with a summary of the physicochemical properties of dopamine-based materials in general. Then detailed description is followed on their applications in the fields of diagnosis and treatment of cancers. The review concludes with an outline of some remaining challenges for dopamine-based materials to be used for clinical applications.