Photo-decomposable Organic Nanoparticles for Combined Tumor Optical Imaging and Multiple Phototherapies

Photodynamic black phosphorus nanosheets functionalized with polymyxin B for targeted ablation of drug-resistant mixed-species biofilms

Biofilms, particularly those formed by multiple bacterial species, pose significant economic and environmental challenges, especially in the context of medical implants. Addressing the urgent need for effective treatment strategies that do not exacerbate drug resistance, we developed a novel nanoformulation, Ce6&PMb@BPN, based on black phosphorus nanosheets (BPN) for targeted treatment of mixed-species biofilms formed by Acinetobacter baumannii (A. baumannii) and methicillin-resistant Staphylococcus aureus (MRSA).The formulation leverages polymyxin B (PMb) for bacterial targeting and chlorin e6 (Ce6) for photodynamic action. Upon near-infrared (NIR) irradiation, Ce6&PMb@BPN efficiently eliminates biofilms by combining chemotherapy, photodynamic therapy (PDT) and photothermal therapy (PTT), reducing biofilm biomass significantly within 30 min. In vivo studies on mice infected with mixed-species biofilm-coated catheters demonstrated the formulation's potent antibacterial and biofilm ablation effects. Moreover, comprehensive biosafety evaluations confirmed the excellent biocompatibility of Ce6&PMb@BPN. Taken together, this intelligently designed nanoformulation holds potential for effectively treating biofilm-associated infections, addressing the urgent need for strategies to combat antibiotic-resistant biofilms, particularly mixed-species biofilm, in medical settings.

Nanoenzymes: A Radiant Hope for the Early Diagnosis and Effective Treatment of Breast and Ovarian Cancers

Breast and ovarian cancers, despite having chemotherapy and surgical treatment, still have the lowest survival rate. Experimental stages using nanoenzymes/nanozymes for ovarian cancer diagnosis and treatment are being carried out, and correspondingly the current treatment approaches to treat breast cancer have a lot of adverse side effects, which is the reason why researchers and scientists are looking for new strategies with less side effects. Nanoenzymes have intrinsic enzyme-like activities and can reduce the shortcomings of naturally occurring enzymes due to the ease of storage, high stability, less expensive, and enhanced efficiency. In this review, we have discussed various ways in which nanoenzymes are being used to diagnose and treat breast and ovarian cancer. For breast cancer, nanoenzymes and their multi-enzymatic properties can control the level of reactive oxygen species (ROS) in cells or tissues, for example, oxidase (OXD) and peroxidase (POD) activity can be used to generate ROS, while catalase (CAT) or superoxide dismutase (SOD) activity can scavenge ROS. In the case of ovarian cancer, most commonly nanoceria is being investigated, and also when folic acid is combined with nanoceria there are additional advantages like inhibition of beta galactosidase. Nanocarriers are also used to deliver small interfering RNA that are effective in cancer treatment. Studies have shown that iron oxide nanoparticles are actively being used for drug delivery, similarly ferritin carriers are used for the delivery of nanozymes. Hypoxia is a major factor in ovarian cancer, therefore MnO2-based nanozymes are being used as a therapy. For cancer diagnosis and screening, nanozymes are being used in sonodynamic cancer therapy for cancer diagnosis and screening, whereas biomedical imaging and folic acid gold particles are also being used for image guided treatments. Nanozyme biosensors have been developed to detect ovarian cancer. This review article summarizes a detailed insight into breast and ovarian cancers in light of nanozymes-based diagnostic and therapeutic approaches.

PEGylated chitosan-coated nanophotosensitizers for effective cancer treatment by photothermal-photodynamic therapy combined with glutathione depletion

The combination of photothermal therapy (PTT) and photodynamic therapy (PDT) has emerged as a promising strategy for cancer treatment. However, the poor photostability and photothermal conversion efficiency (PCE) of organic small-molecule photosensitizers, and the intracellular glutathione (GSH)-mediated singlet oxygen scavenging largely decline the antitumor efficacy of PTT and PDT. Herein, a versatile nanophotosensitizer (NPS) system is developed by ingenious incorporation of indocyanine green (ICG) into the PEGylated chitosan (PEG-CS)-coated polydopamine (PDA) nanoparticles via multiple π-π stacking, hydrophobic and electrostatic interactions. The PEG-CS-covered NPS showed prominent colloidal and photothermal stability as well as high PCE (ca 62.8 %). Meanwhile, the Michael addition between NPS and GSH can consume GSH, thus reducing the GSH-induced singlet oxygen scavenging. After being internalized by CT26 cells, the NPS under near-infrared laser irradiation produced massive singlet oxygen with the aid of thermo-enhanced intracellular GSH depletion to elicit mitochondrial damage and lipid peroxide formation, thus leading to ferroptosis and apoptosis. Importantly, the combined PTT and PDT delivered by NPS effectively inhibited CT26 tumor growth in vivo by light-activated intense hyperthermia and redox homeostasis disturbance. Overall, this work presents a new tactic of boosting antitumor potency of ICG-mediated phototherapy by PEG-CS-covered NPS.

Cationic Porphyrin-Based Ionic Nanomedicines for Improved Photodynamic Therapy

This study presents the synthesis and characterization of monosubstituted cationic porphyrin as a photodynamic therapeutic agent. Cationic porphyrin was converted into ionic materials by using a single-step ion exchange reaction. The small iodide counteranion was replaced with bulky BETI and IR783 anions to reduce aggregation and enhance the photodynamic effect of porphyrin. Carrier-free ionic nanomedicines were then prepared by using the reprecipitation method. The photophysical characterization of parent porphyrin, ionic materials, and ionic nanomaterials, including absorbance, fluorescence and phosphorescence emission, quantum yield, radiative and nonradiative rate, and lifetimes, was performed. The results revealed that the counteranion significantly affects the photophysical properties of porphyrin. The ionic nanomaterials exhibited an increase in the reactive oxygen yield and enhanced cytotoxicity toward the MCF-7 cancer cell line. Examination of results revealed that the ionic materials exhibited an enhanced photodynamic therapeutic activity with a low IC50 value (nanomolar) in cancerous cells. These nanomedicines were mainly localized in the mitochondria. The improved light cytotoxicity is attributed to the enhanced photophysical properties and positive surface charge of the ionic nanomedicines that facilitate efficient cellular uptake. These results demonstrate that ionic material-based nanodrugs are promising photosensitizers for photodynamic therapy.

Aptamer-functionalized quantum dots as theranostic nanotools against cancer and bacterial infections: A comprehensive overview of recent trends

Aptamers (Apts) are synthetic nucleic acid ligands that can be engineered to target various molecules, including amino acids, proteins, and pharmaceuticals. Through a series of adsorption, recovery, and amplification steps, Apts are extracted from combinatorial libraries of synthesized nucleic acids. Using aptasensors in bioanalysis and biomedicine can be improved by combining them with nanomaterials. Moreover, Apt-associated nanomaterials, including liposomes, polymeric, dendrimers, carbon nanomaterials, silica, nanorods, magnetic NPs, and quantum dots (QDs), have been widely used as promising nanotools in biomedicine. Following surface modifications and conjugation with appropriate functional groups, these nanomaterials can be successfully used in aptasensing. Advanced biological assays can use Apts immobilized on QD surfaces through physical interaction and chemical bonding. Accordingly, modern QD aptasensing platforms rely on interactions between QDs, Apts, and targets to detect them. QD-Apt conjugates can be used to directly detect prostate, ovarian, colorectal, and lung cancers or simultaneously detect biomarkers associated with these malignancies. Tenascin-C, mucin 1, prostate-specific antigen, prostate-specific membrane antigen, nucleolin, growth factors, and exosomes are among the cancer biomarkers that can be sensitively detected using such bioconjugates. Furthermore, Apt-conjugated QDs have shown great potential for controlling bacterial infections such as Bacillus thuringiensis, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, Campylobacter jejuni, Staphylococcus aureus, and Salmonella typhimurium. This comprehensive review discusses recent advancements in the design of QD-Apt bioconjugates and their applications in cancer and bacterial theranostics.

Sialic acid-targeting multi-functionalized silicon quantum dots for synergistic photodynamic and photothermal cancer therapy

To explore the potential of silicon quantum dots (SiQDs) in combined photodynamic therapy (PDT) and photothermal therapy (PTT), we engineered the surface of SiQDs with the photosensitizer Ce6 and the tumor-cell-targeting ligand phenylboronic acid (PBA) via polydopamine-mediated chemistry. Upon irradiation with light of specific wavelengths, SiQDs@Ce6/PBA could generate high levels of reactive oxygen species (ROS) and trigger effective photo-to-thermal conversion. PBA-conjugation could not only increase the cellular uptake and transcellular transport capability of nanoparticles, but also enhance their tumor accumulation. In the presence of a 635 nm laser, SiQDs@Ce6/PBA was able to trigger intracellular ROS production, which further altered the mitochondrial membrane potential and promoted apoptosis of tumor cells. Finally, combined PDT/PTT treatments led to synergistically enhanced cancer cell killing and tumor-growth inhibition effects. This study demonstrates the surface engineering of silicon quantum dots for synergistic PDT/PTT cancer therapy.

Combinatorial Polydopamine-Liposome Nanoformulation as an Effective Anti-Breast Cancer Therapy

Introduction

Drug delivery systems (DDSs) based on liposomes are potential tools to minimize the side effects and substantially enhance the therapeutic efficacy of chemotherapy. However, it is challenging to achieve biosafe, accurate, and efficient cancer therapy of liposomes with single function or single mechanism. To solve this problem, we designed a multifunctional and multimechanism nanoplatform based on polydopamine (PDA)-coated liposomes for accurate and efficient combinatorial cancer therapy of chemotherapy and laser-induced PDT/PTT.

Methods

ICG and DOX were co-incorporated in polyethylene glycol modified liposomes, which were further coated with PDA by a facile two-step method to construct PDA-liposome nanoparticles (PDA@Lipo/DOX/ICG). The safety of nanocarriers was investigated on normal HEK-293 cells, and the cellular uptake, intracellular ROS production capacity, and combinatorial treatment effect of the nanoparticles were assessed on human breast cancer cells MDA-MB-231. In vivo biodistribution, thermal imaging, biosafety assessment, and combination therapy effects were estimated based on MDA-MB-231 subcutaneous tumor model.

Results

Compared with DOX·HCl and Lipo/DOX/ICG, PDA@Lipo/DOX/ICG showed higher toxicity on MDA-MB-231 cells. After endocytosis by target cells, PDA@Lipo/DOX/ICG produced a large amount of ROS for PDT by 808 nm laser irradiation, and the cell inhibition rate of combination therapy reached up to 80.4%. After the tail vein injection (DOX equivalent of 2.5 mg/kg) in mice bearing MDA-MB-231 tumors, PDA@Lipo/DOX/ICG significantly accumulated at the tumor site at 24 h post injection. After 808 nm laser irradiation (1.0 W/cm², 2 min) at this timepoint, PDA@Lipo/DOX/ICG efficiently suppressed the proliferation of MDA-MB-231 cell and even thoroughly ablated tumors. Negligible cardiotoxicity and no treatment-induced side effects were observed.

Conclusion

PDA@Lipo/DOX/ICG is a multifunctional nanoplatform based on PDA-coated liposomes for accurate and efficient combinatorial cancer therapy of chemotherapy and laser-induced PDT/PTT.

Systematic Screening and Therapeutic Evaluation of Glyconanoparticles with Differential Cancer Affinities for Targeted Cancer Therapy

Cancer-targeting ligands used for nanomedicines have been limited mostly to antibodies, peptides, aptamers, and small molecules thus far. Here, a library of glycocalyx-mimicking nanoparticles as a platform to enable screening and identification of cancer-targeting nanomedicines is reported. Specifically, a library of 31 artificial glycopolymers composed of either homogeneous or heterogeneous display of five different sugar moieties (β-glucose, β-galactose, α-mannose, β-N-acetyl glucosamine, and β-N-acetyl galactosamine) is converted to a library of glyconanoparticles (GlyNPs). GlyNPs optimal for targeting CT26, DU145, A549, and PC3 tumors are systematically screened and identified. The cypate-conjugated GlyNP displaying α-mannose and β-N-acetyl glucosamine show selective targeting and potent photothermal therapeutic efficacy against A549 human lung tumors. The docetaxel-contained GlyNP displaying β-glucose, β-galactose, and α-mannose demonstrate targeted chemotherapy against DU145 human prostate tumors. The results presented herein collectively demonstrate that the GlyNP library is a versatile platform enabling the identification of cancer-targeting glyconanoparticles and suggest its potential applicability for targeting various diseased cells beyond cancer.

Penetration and photodynamic ablation of drug-resistant biofilm by cationic Iron oxide nanoparticles

As we step into the post-antibiotic era, the accelerated emergence of antibiotic-resistant pathogenic bacteria poses an increasingly serious threat to public health. The formation of antibiotic-resistant biofilms further challenges currently available drugs and treatment options, calling for novel strategies for effective ablation of such biofilm with minimal concern on safety and development of resistance. Herein, we report a novel type of photodynamic nanoagent, composed of chlorin e6 (Ce6)-loaded water-soluble chitosan-coated iron oxide nanoparticles (named Ce6@WCS-IONP), for drug-resistant bacteria killing and biofilm eradication. The fabricated Ce6@WCS-IONP has negligible toxicity to mammalian cells and exhibited equivalent singlet oxygen generation capacity to free Ce6; however, its association with methicillin-resistant Staphylococcus aureus (MRSA) was greatly enhanced, as evidenced by flow cytometry analysis and transmission electron microscope. In vitro studies verified that Ce6@WCS-IONP has superior photodynamic bactericidal effect against planktonic MRSA. Furthermore, with the aid of the cationic nature and small size, Ce6@WCS-IONP could effectively penetrate into MRSA biofilm, revealed by 3D fluorescence imaging. Both biomass analysis and viable bacteria counting demonstrated that Ce6@WCS-IONP showed potent biofilm ablation efficacy, averagely 7.1 log unit lower than that in free Ce6 group upon identical light irradiation. In addition, local treatment of MRSA-infected mice with Ce6@WCS-IONP plus light irradiation resulted in significant antibacterial and wound healing effect, accompanied by good biocompatibility in vivo. Collectively, photosensitizer-loaded cationic IONP with effective biofilm penetration and photodynamic eradication potential might be a promising nano platform in fighting against antibiotic-resistant microbial pathogen and biofilm.

Polymethine dyes for PDT: recent advances and perspectives to drive future applications

It has been proved that the effectiveness of photodynamic therapy (PDT) is closely related to the intrinsic features of the photosensitizer (PS). Over the recent years, several efforts have been devoted to the discovery of novel and more efficient photosensitizers showing higher efficacy and lower side effects. In this context, squaraine and cyanine dyes have been reported to potentially overcome the drawbacks related to the traditional PSs. In fact, squaraines and cyanines are characterized by sharp and intense absorption bands and narrow emission bands with high extinction coefficients typically in the red and near-infrared region, good photo and thermal stability and a strong fluorescent emission in organic solvents. In addition, biocompatibility and low toxicity make them suitable for biological applications. Despite these interesting intrinsic features, their chemical instability and self-aggregation properties in biological media still limit their use in PDT. To overcome these drawbacks, the self-assembly and incorporation into smart nanoparticle systems are forwarded promising approaches that can control their physicochemical properties, providing rational solutions for the limitation of free dye administration in the PDT application. The present review summarizes the latest advances in squaraine and cyanine dyes for PDT application, analyzing the different strategies, i.e.the self-assembly and the incorporation into nanoparticles, to further enhance their photochemical properties and therapeutic potential. The in vivo assessments are still limited, thus further delaying their effective application in PDT.

Light-Decomposable Polymeric Micelles with Hypoxia-Enhanced Phototherapeutic Efficacy for Combating Metastatic Breast Cancer

Oxygen dependence and anabatic hypoxia are the major factors responsible for the poor outcome of photodynamic therapy (PDT) against cancer. Combining of PDT and hypoxia-activatable bioreductive therapy has achieved remarkably improved antitumor efficacy compared to single PDT modality. However, controllable release and activation of prodrug and safety profiles of nanocarrier are still challenging in the combined PDT/hypoxia-triggered bioreductive therapy. Herein, we developed a near infrared (NIR) light-decomposable nanomicelle, consisting of PEGylated cypate (pCy) and mPEG-polylactic acid (mPEG_2k-PLA_2k) for controllable delivery of hypoxia-activated bioreductive prodrug (tirapazamine, TPZ) (designated TPZ@pCy), for combating metastatic breast cancer via hypoxia-enhanced phototherapies. TPZ@pCy was prepared by facile nanoprecipitation method, with good colloidal stability, excellent photodynamic and photothermal potency, favorable light-decomposability and subsequent release and activation of TPZ under irradiation. In vitro experiments demonstrated that TPZ@pCy could be quickly internalized by breast cancer cells, leading to remarkable synergistic tumor cell-killing potential. Additionally, metastatic breast tumor-xenografted mice with systematic administration of TPZ@pCy showed notable tumor accumulation, promoting tumor ablation and lung metastasis inhibition with negligible toxicity upon NIR light illumination. Collectively, our study demonstrates that this versatile light-decomposable polymeric micelle with simultaneous delivery of photosensitizer and bioreductive agent could inhibit tumor growth as well as lung metastasis, representing a promising strategy for potent hypoxia-enhanced phototherapies for combating metastatic breast cancer.

Improved Photophysical Properties of Ionic Material-Based Combination Chemo/PDT Nanomedicine

Herein, a cost-effective and prompt approach to develop ionic material-based combination nanodrugs for cancer therapy is presented. A chemotherapeutic (phosphonium) cation and photodynamic therapeutic (porphyrin) anion are combined using a single step ion exchange reaction. Afterward, a nanomedicine is prepared from this ionic materials-based combination drug using a simplistic strategy of reprecipitation. Improved photophysical characteristics such as a slower nonradiative rate constant, an enhanced phosphorescence emission, a longer lifetime, and a bathochromic shift in absorbance spectra of porphyrin are observed in the presence of a chemotherapeutic countercation. The photodynamic therapeutic activity of nanomedicines is investigated by measuring the singlet oxygen quantum yield using two probes. As compared to the parent porphyrin compound, the synthesized combination material showed a 2-fold increase in the reactive oxygen species quantum yield, due to inhibition of face-to-face aggregation of porphyrin units in the presence of bulky chemotherapeutic ions. The dark cytotoxicity of combination therapy nanomedicines in the MCF-7 (cancerous breast) cell line is also increased as compared to their corresponding parent compounds in vitro. This is due to the high cellular uptake of the combination nanomedicines as compared to that of the free drug. Further, selective toxicity toward cancer cells was acquired by functionalizing nanomedicine with folic acid followed by incubation with MCF-7 and MCF-10A (noncancerous breast). Light toxicity experiments indicate that the synthesized ionic nanomedicine shows a greater cell death than either parent drug due to the improved photophysical properties and effective combination effect. This facile and economical strategy can easily be utilized in the future to develop many other combination ionic nanomedicines with improved photodynamics.

A natural anthocyanin-based multifunctional theranostic agent for dual-modal imaging and photothermal anti-tumor therapy

Nowadays, cancer is one of the most serious diseases threatening the health of human beings, and imaging-guided photothermal therapy (PTT) is rapidly emerging as a potent oncotherapy strategy due to its unique advantages of high efficiency, noninvasiveness, visualization, and accuracy. In this study, a multifunctional nanoplatform based on gadolinium ion chelated natural anthocyanins (ACNs) is reported, which can be used not only as an excellent photoacoustic/magnetic resonance (PA/MR) dual-modal contrast agent but also for imaging-guided tumor PTT. The nanoparticles obtained have a suitable size, good dispersity, and physiological stability. The excellent biocompatibility and remarkable photothermal effect of the nanoparticles in vitro were demonstrated by CCK-8 assays and co-staining experiments. Moreover, the magnetic resonance imaging (MRI) and photoacoustic imaging (PAI) results obtained in vivo showed that the nanoparticles were ideal dual-modal contrast agents whether given by intravenous or intratumoral injection. After intratumoral injection, the dual-modal PAI/MRI was used for determining the maximum diffusion time of the probe in the tumor site to guide laser treatment, achieving complete tumor elimination without normal tissue injury. Importantly, ACN is a natural compound extracted from black carrots, possessing native biocompatibility and biodegradability, which was further proved by the results of the detailed safety evaluation. Overall, the as-prepared nanoparticles displayed significant tumor diagnosis and treatment effects while mitigating biosafety concerns, and thus this was found to be a promising nanotherapeutic method for cancer treatment.

Hyaluronic Acid Coated Liposomes Co-Delivery of Natural Cyclic Peptide RA-XII and Mitochondrial Targeted Photosensitizer for Highly Selective Precise Combined Treatment of Colon Cancer

Background

Natural cyclopeptide RA-XII, isolated from Rubia yunnanensis, is a promising chemotherapeutic agent for colon cancer. The photosensitizer protoporphyrin-IX attached with triphenylphosphonium (TPP) could possess mitochondria targeting capacity and exert photodynamic therapy (PDT) by inducing oxidizing damage to the mitochondria and cell apoptosis eventually. In this work, pH-sensitive liposomes were constructed to simultaneously deliver RA-XII as a chemotherapeutic drug and modified porphyrin as a mitochondria-targeting photosensitizer to treat colon cancer, and verified its mechanism of action and antitumor therapeutic efficacy.

Methods

The colon cancer targeting liposome nanoparticle RA/TPPP-Lip was synthesized using thin film hydration. The therapeutic effect and targeting ability of RA/TPPP-Lip was investigated in vitro. And use HCT116 cell allogeneic subcutaneous transplantation tumor model to investigate the anti-tumor and targeting effects of RA/TPPP-Lip in vivo.

Results

RA/TPPP-Lip gained the targeting ability through surface-modified HA to increase the accumulation of RA-XII and TPPP in colon cancer cells. A series of in vitro experimental results showed that TPPP produced cytotoxic ROS under laser irradiation to directly damage cell mitochondria and played a combined role with RA-XII, making RA/TPPP-Lip the best colon cancer cell growth inhibitory effect. Furthermore, in vivo antitumor experiments showed that the RA/TPPP-Lip substantially accumulated at the tumor site and efficiently repressed tumor growth in nude mice.

Conclusion

We have successfully designed a new cancer-targeted nanomedicine platform (RA/TPPP-Lip) for the collaborative treatment of colon cancer, which can achieve the targeted continuous release of multiple therapeutic drugs. This work provides a new strategy for precise combination therapy, which may promote the further development of collaborative cancer treatment platforms.

Semiconductor small molecule IHIC/ITIC applied to photothermal therapy and photoacoustic imaging of tumors

Organic semiconductor small molecules IHIC and ITIC have been developed as solar cell materials, and because of their strong near-infrared absorption capabilities, they are promising for cancer phototherapy. This article reports the application of semiconductor small molecule IHIC/ITIC liposomes in photothermal therapy and photoacoustic imaging of tumors firstly. Experiments show that the liposome-loaded IHIC/ITIC material has good biocompatibility and can be effectively enriched in tumor sites. After being irradiated with laser, it can emit strong photoacoustic signals, and has achieved good results in the photothermal treatment of breast cancer mice. We believe that organic semiconductor small molecule IHIC/ITIC will become a promising photothermal agent with wonderful development possibilities.

Facile Synthesis of a Croconaine-Based Nanoformulation for Optoacoustic Imaging and Photothermal Therapy

Near-infrared (NIR) light absorbing theranostic agents can integrate optoacoustic imaging and photothermal therapy for effective personalized precision medicine. However, most of these agents face the challenges of unstable optical properties, material-associated toxicity, and nonbiodegradability, all of which limit their biomedical application. Several croconaine-based organic agents able to overcome some of these limitations have been recently reported, but these suffer from complicated multistep synthesis protocols. Herein, the use of CR760, a croconaine dye with excellent optical properties, is reported for nanoparticle formulation and subsequent optoacoustic imaging and photothermal therapy. Importantly, CR760 can be conveniently prepared in a single step from commercially available materials. Furthermore, CR760 can be covalently attached, via a polyethylene glycol linker, to the α_v β₃ integrin ligand c(RGDyC), resulting in self-assembled nanoparticles (NPs) with cancer-targeting capability. Such CR760RGD-NPs exhibit strong NIR absorption, high photostability, high optoacoustic generation efficiency, and active tumor-targeting, making them ideal candidates for optoacoustic imaging. Due to favorable electron transfer, CR760RGD-NPs display a 45.37% photothermal conversion efficiency thereby rendering them additionally useful for photothermal therapy. Targeted tumor elimination, biosafety, and biocompatibility are demonstrated in a 4T1 murine breast tumor model. This work points to the use of CR760RGD-NPs as a promising nanoagent for NIR-based cancer phototheranostics.

A cyanine-based polymeric nanoplatform with microenvironment-driven cascaded responsiveness for imaging-guided chemo-photothermal combination anticancer therapy

Finding out how to overcome multistage biological barriers for nanocarriers in cancer therapy to obtain highly precise drug delivery is still a challenge. Herein, we prepared a multistage and cascaded switchable polymeric nanovehicle, self-assembled from polyethylene glycol grafted amphiphilic copolymer containing hydrophobic poly(ortho ester) and hydrophilic ethylenediamine-modified poly(glycidyl methacrylate) (PEG-g-p(GEDA-co-DMDEA)) for imaging-guided chemo-photothermal combination anticancer therapy. Notably, a novel ATRP initiator containing cyanine dye was designed and attached to the polymer, providing the nanovehicle with NIR-light induced photothermal and fluorescent properties. The PEG shell displayed tumor-microenvironment-induced detachment, resulting in the surface charge change of the nanovehicle from neutral to positive and thus enhancing cellular uptake. Subsequently, the hydrophobic pDMDEA hydrolyzed into a hydrophilic segment in the acidic lysosome, leading to sufficient drug release. Finally, with the aid of the photothermal property, the therapeutic drug DOX successfully escaped from the lysosome to exert chemotherapy. This well-defined polymeric nanoplatform promoted the development of designing novel theranostic polymeric nanovehicles for precise cancer therapy.

Cyanine conjugates in cancer theranostics

Cyanine is a meritorious fluorogenic core for the construction of fluorescent probes and its phototherapeutic potential has been enthusiastically explored as well. Alternatively, the covalent conjugation of cyanine with other potent therapeutic agents not only boosts its therapeutic efficacy but also broadens its therapeutic modality. Herein, we summarize miscellaneous cyanine-therapeutic agent conjugates in cancer theranostics from literature published between 2014 and 2020. The application scenarios of such theranostic cyanine conjugates covered common cancer therapeutic modalities, including chemotherapy, phototherapy and targeted therapy. Besides, cyanine conjugates that serve as nanocarriers for drug delivery are introduced as well. In an additional section, we analyze the potential of these conjugates for clinical translation. Overall, this review is aimed to stimulate research interest in exploring unattempted therapeutic agents and novel conjugation strategies and hopefully, accelerate clinical translation in this field.

Rational Design of Near-Infrared-Absorbing Pt(II)-Chelated Azadipyrromethene Dyes as a New Generation of Photosensitizers for Synergistic Phototherapy

Pt(II) photosensitizers are emerging as novel Pt anticancer agents for cancer photodynamic therapy (PDT) to avoid uncontrollable toxicity of cisplatin. However, the application of Pt(II) photosensitizers is limited by tumor hypoxia and the poor penetration depth of excitation light. To overcome these drawbacks, exploiting the next generation of Pt anticancer agents is of urgent need. According to theoretical calculations, novel near-infrared (NIR)-absorbing Pt(II)-chelated azadipyrromethene dyes (PtDP-X, where X = N, C, and S) were designed. Importantly, spin-orbit coupling of the Pt atom could promote the intersystem crossing of a singlet-to-triplet transition for converting oxygen to singlet oxygen (¹O₂), and the azadipyrromethene skeleton could provide a strong photothermal effect. As expected, PtDP-X exhibited intense NIR absorption and synergistic PDT and photothermal effects with low dark cytotoxicity. Furthermore, water-soluble and biocompatible PtDP-N nanoparticles (PtDP-N NPs) were prepared that achieved effective tumor cell elimination with low side effects under 730 nm light irradiation in vitro and in vivo. This pioneering work could push the exploitation of NIR-absorbing metal-chelated azadipyrromethene dyes, so as to promote the positive evolution of phototherapy agents.

Self-assembled heptamethine cyanine dye dimer as a novel theranostic drug delivery carrier for effective image-guided chemo-photothermal cancer therapy

Near-infrared (NIR)-induced dye-based theranostic drug delivery carriers are used for critical image-guided chemo-photothermal cancer therapy. However, most carriers fail to deliver sufficient heat and fluorescence efficiently due to direct π-π stacking of the aromatic rings of the NIR dye and drug. In the work reported herein, we examined a self-assembled heptamethine cyanine dye dimer (CyD) with improved heat and fluorescence delivery that was developed by manipulating the unique structural and optical properties of the dimer. The H-aggregation of CyD in an aqueous solution generated a great amount of heat by transforming the energy of the excited electrons into non-radiative energy. Moreover, the disulfide bond of CyD assisted nanoparticles with a drug by minimizing the interaction between the NIR dye and drug, and also by releasing the drug in a redox environment. As a result, DOX encapsulated within CyD (CyD/DOX) showed strong heat generation and fluorescence imaging in tumor-bearing mice, allowing detection of the tumor site and inhibition of tumor growth by chemo-photothermal therapy. The multiplicity of features supplied by the newly developed CyD demonstrated the potential of CyD/DOX as an NIR dye-based theranostic drug-delivery carrier for effective chemo-photothermal cancer therapy.

Surface-modified polymeric nanoparticles for drug delivery to cancer cells

INTRODUCTION

The utilization of polymeric nanoparticles, as drug payloads, has been extensively prevailed in cancer therapy. However, the precise distribution of these nanocarriers is restrained by various physiological and cellular obstacles. Nanoparticles must avoid nonspecific interactions with healthy cells and in vivo compartments to circumvent these barriers. Since in vivo interactions of nanoparticles are mainly dependent on surface properties of nanoparticles, efficient control on surface constituents is necessary for the determination of nanoparticles' fate in the body.

AREAS COVERED

In this review, the surface-modified polymeric nanoparticles and their utilization in cancer treatment were elaborated. First, the interaction of nanoparticles with numerous in vivo barriers was highlighted. Second, different strategies to overcome these obstacles were described. Third, some inspiring examples of surface-modified nanoparticles were presented. Later, fabrication and characterization methods of surface-modified nanoparticles were discussed. Finally, the applications of these nanoparticles in different routes of treatments were explored.

EXPERT OPINION

Surface modification of anticancer drug-loaded polymeric nanoparticles can enhance the efficacy, selective targeting, and biodistribution of the anticancer drug at the tumor site.

Handheld endomicroscope using a fiber-optic harmonograph enables real-time and in vivo confocal imaging of living cell morphology and capillary perfusion

Confocal laser endomicroscopy provides high potential for noninvasive and in vivo optical biopsy at the cellular level. Here, we report a fully packaged handheld confocal endomicroscopic system for real-time, high-resolution, and in vivo cellular imaging using a Lissajous scanning fiber-optic harmonograph. The endomicroscopic system features an endomicroscopic probe with a fiber-optic harmonograph, a confocal microscope unit, and an image signal processor. The fiber-optic harmonograph contains a single mode fiber coupled with a quadrupole piezoelectric tube, which resonantly scans both axes at ~ 1 kHz to obtain a Lissajous pattern. The fiber-optic harmonograph was fully packaged into an endomicroscopic probe with an objective lens. The endomicroscopic probe was hygienically packaged for waterproofing and disinfection of medical instruments within a 2.6-mm outer diameter stainless tube capable of being inserted through the working channel of a clinical endoscope. The probe was further combined with the confocal microscope unit for indocyanine green imaging and the image signal processor for high frame rate and high density Lissajous scanning. The signal processing unit delivers driving signals for probe actuation and reconstructs confocal images using the auto phase matching process of Lissajous fiber scanners. The confocal endomicroscopic system was used to successfully obtain human in vitro fluorescent images and real-time ex vivo and in vivo fluorescent images of the living cell morphology and capillary perfusion inside a single mouse.

Application of Nanomaterials in Biomedical Imaging and Cancer Therapy

Nanomaterials, such as nanoparticles, nanorods, nanosphere, nanoshells, and nanostars, are very commonly used in biomedical imaging and cancer therapy. They make excellent drug carriers, imaging contrast agents, photothermal agents, photoacoustic agents, and radiation dose enhancers, among other applications. Recent advances in nanotechnology have led to the use of nanomaterials in many areas of functional imaging, cancer therapy, and synergistic combinational platforms. This review will systematically explore various applications of nanomaterials in biomedical imaging and cancer therapy. The medical imaging modalities include magnetic resonance imaging, computed tomography, positron emission tomography, single photon emission computerized tomography, optical imaging, ultrasound, and photoacoustic imaging. Various cancer therapeutic methods will also be included, including photothermal therapy, photodynamic therapy, chemotherapy, and immunotherapy. This review also covers theranostics, which use the same agent in diagnosis and therapy. This includes recent advances in multimodality imaging, image-guided therapy, and combination therapy. We found that the continuous advances of synthesis and design of novel nanomaterials will enhance the future development of medical imaging and cancer therapy. However, more resources should be available to examine side effects and cell toxicity when using nanomaterials in humans.

Tumor Microenvironment-triggered Nanosystems as dual-relief Tumor Hypoxia Immunomodulators for enhanced Phototherapy

Photodynamic therapy (PDT) is a promising strategy in cancer treatment that utilizes photosensitizers (PSs) to produce reactive oxygen species (ROS) and eliminate cancer cells under specific wavelength light irradiation. However, special tumor environments, such as those with overexpression of glutathione (GSH), which will consume PDT-mediated ROS, as well as hypoxia in the tumor microenvironment (TME) could lead to ineffective treatment. Moreover, PDT is highly light-dependent and therefore can be hindered in deep tumor cells where light cannot easily penetrate. To solve these problems, we designed oxygen-dual-generating nanosystems MnO2@Chitosan-CyI (MCC) for enhanced phototherapy. Methods: The TME-sensitive nanosystems MCC were easily prepared through the self-assembly of iodinated indocyanine green (ICG) derivative CyI and chitosan, after which the MnO2 nanoparticles were formed as a shell by electrostatic interaction and Mn-N coordinate bonding. Results: When subjected to NIR irradiation, MCC offered enhanced ROS production and heat generation. Furthermore, once endocytosed, MnO2 could not only decrease the level of GSH but also serve as a highly efficient in situ oxygen generator. Meanwhile, heat generation-induced temperature increase accelerated in vivo blood flow, which effectively relieved the environmental tumor hypoxia. Furthermore, enhanced PDT triggered an acute immune response, leading to NIR-guided, synergistic PDT/photothermal/immunotherapy capable of eliminating tumors and reducing tumor metastasis. Conclusion: The proposed novel nanosystems represent an important advance in altering TME for improved clinical PDT efficacy, as well as their potential as effective theranostic agents in cancer treatment.

Reduced graphene oxide, but not carbon nanotubes, slows murine melanoma after thermal ablation using LED light in B16F10 lineage cells

Photodynamic therapy is a minimally invasive health technology used to treat cancer and other non-malignant diseases, as well as inactivation of viruses, bacteria and fungi. In this work, we sought to combine the phototherapy technique using low intensity LED (660 nm) to induce ablation in melanoma tumor in mice treated with nanoparticles. In vitro and in vivo studies were conducted, and our results demonstrated that multi-walled carbon nanotubes (MWCNTs) do not destroy tumor cells in vivo, but stimulate the inflammatory process and angiogenesis. Reduced graphene oxide (rGO), has been shown to play a protective role associated with the LED ablation, inducing necrosis, stimulation of immune response by lymphoproliferation, and decreased tumor mass in vivo. We consider that LED alone can be very effective in controlling the growth of melanoma tumors and its association with rGO is potentiated.

Targeted nanocarriers based on iodinated-cyanine dyes as immunomodulators for synergistic phototherapy

Photodynamic therapy (PDT), as one of the most powerful photo-therapeutic strategies for cancer treatment with minimum invasiveness, can effectively damage local tumor cells and significantly induce systemic antitumor immunity. However, current nanotechnology-assisted PDT-immunomodulators have either poor penetration for deep tumors or low singlet oxygen generation. Herein, we construct a novel theranostic nanocarrier (HA-PEG-CyI, HPC) by inducing the self-assembly of PEGylated CyI and attaching the ligand HA to its surface. The prepared HPC can be used as an ideal PDT-immunomodulator for synergistic cancer therapy. CyI is an iodinated-cyanine dye with enhanced singlet oxygen generation ability as well as excellent photo-to-photothermal and near-infrared fluorescence imaging properties. Under 808 nm laser irradiation, the prepared HPC can generate both reactive oxygen species (ROS) and elevate temperature which can subsequently result in apoptosis and necrosis at tumor sites. Moreover, the HPC-induced cell death can generate a series of acute inflammatory reactions, leading to systemic immunity induction and secondary death of tumor cells, which further results in reducing tumor recurrence. In vitro and in vivo results show that HPC can enhance the tumor targeting efficacy, generate ROS efficiently and exhibit a high temperature response under NIR irradiation, which working together can activate immune responses for synergistic phototherapy on tumor cells. Accordingly, the proposed multi-functional HPC nanocarriers represent an important advance in PDT and can be used as a superior cancer treatment strategy with great promise for clinical applications.

Nano-Medicine for Thrombosis: A Precise Diagnosis and Treatment Strategy

Thrombosis is a global health issue and one of the leading factors of death. However, its diagnosis has been limited to the late stages, and its therapeutic window is too narrow to provide reasonable and effective treatment. In addition, clinical thrombolytics suffer from a short half-life, allergic reactions, inactivation, and unwanted tissue hemorrhage. Nano-medicines have gained extensive attention in diagnosis, drug delivery, and photo/sound/magnetic-theranostics due to their convertible properties. Furthermore, diagnosis and treatment of thrombosis using nano-medicines have also been widely studied. This review summarizes the recent advances in this area, which revealed six types of nanoparticle approaches: (1) in vitro diagnostic kits using "synthetic biomarkers"; (2) in vivo imaging using nano-contrast agents; (3) targeted drug delivery systems using artificial nanoparticles; (4) microenvironment responsive drug delivery systems; (5) drug delivery systems using biological nanostructures; and (6) treatments with external irradiation. The investigations of nano-medicines are believed to be of great significance, and some of the advanced drug delivery systems show potential applications in clinical theranotics.

Prototypic Heptamethine Cyanine Incorporating Nanomaterials for Cancer Phototheragnostic

Developing technologies that allow the simultaneous diagnosis and treatment of cancer (theragnostic) has been the quest of numerous interdisciplinary research teams. In this context, nanomaterials incorporating prototypic near infrared (NIR)-light responsive heptamethine cyanines have been showing very promising results for cancer theragnostic. The precisely engineered features of these nanomaterials endow them with the ability to achieve a high tumor accumulation, enabling a tumor's visualization by NIR fluorescence and photoacoustic imaging modalities. Upon interaction with NIR light, the tumor-homed heptamethine cyanine-incorporating nanomaterials can also produce a photothermal/photodynamic effect with a high spatio-temporal resolution and minimal side effects, leading to an improved therapeutic outcome. This progress report analyses the application of nanomaterials incorporating prototypic NIR-light responsive heptamethine cyanines (IR775, IR780, IR783, IR797, IR806, IR808, IR820, IR825, IRDye 800CW, and Cypate) for cancer photothermal therapy, photodynamic therapy, and imaging. Overall, the continuous development of nanomaterials incorporating the prototypic NIR absorbing heptamethine cyanines will cement their phototheragnostic capabilities.

PEGylated WS2 nanodrug system with erythrocyte membrane coating for chemo/photothermal therapy of cervical cancer

The side effects of chemical drugs and multi-drug resistance are serious obstacles hindering efficient tumor therapy.

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.

Enzyme-induced in vivo assembly of gold nanoparticles for imaging-guided synergistic chemo-photothermal therapy of tumor

This article describes a nanoplatform based on matrix metalloproteinase (MMP)-responsive gold nanoparticles (AuNPs) for tumor-targeted photoacoustic (PA) imaging-guided photothermal therapy and drug delivery. AuNPs were grafted with complementary DNA strands, tethered with doxorubicin and coated with poly(ethylene glycol) via a thermal-labile linker and a MMP-cleavable peptide, respectively. The nanoprobes remained well-isolated in healthy tissues, but formed aggregates rapidly under MMP-abundant conditions. The DNA hybridization-induced assembly of the nanoprobes led to prolonged tumor retention and strong near-infrared (NIR) absorption, which is beneficial to deep-tissue imaging and therapy. Compared with MMP-inert nanoprobes, our platform demonstrated significantly enhanced efficiency in PA imaging and photothermal conversion upon NIR irradiation. Meanwhile, doxorubicin could be released rapidly in response to the localized elevation of temperature, leading to synergistic chemo-photothermal therapy. The unique nanoplatform may find applications in effective disease control by delivering imaging and therapy to tumors with high specificity, safety, and universality.

Photodynamic Chitosan Nano-Assembly as a Potent Alternative Candidate for Combating Antibiotic-Resistant Bacteria

The fact that increasing antibiotic resistance of pathogenic bacteria and a lack of new potent broad-spectrum antibiotics call for the development of alternative approaches for treating infectious diseases. With the merits of great efficacy, safety, and facile implementation, antibacterial photodynamic therapy (APDT) represents an attractive modality for this purpose. Here, we report that the newly fabricated photodynamic chitosan nano-assembly, designated CS-Ce6, could synergistically kill antibiotic-resistant bacteria with superior potency to vancomycin. CS-Ce6 nano-assembly, obtained from covalent conjugate of chlorin e6 (Ce6) with chitosan, exhibited strong association with bacteria, thus altering their morphologies and mediating great delivery efficiency of Ce6. Upon light irradiation, localized generation of singlet oxygen by CS-Ce6 nano-assembly has a remarkable bactericidal effect toward both drug-resistance Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative Acinetobacter baumannii, which was greater than that the free Ce6 and antibiotics had. We also confirmed that APDT-treated MRSA neither developed resistance to APDT nor altered their resistance to methicillin. Our in vivo studies demonstrated that the CS-Ce6 nano-assembly had comparable therapeutic efficacy with vancomycin in MRSA-infected mice. These results suggest that APDT by photodynamic chitosan nano-assembly hold great potential in combating antibiotic-resistant bacteria and hopefully in reducing the need of antibiotics in the future.

NIR-guided dendritic nanoplatform for improving antitumor efficacy by combining chemo-phototherapy

Background

Phototherapy, including photothermal therapy (PTT) and photodynamic therapy (PDT), is a promising noninvasive strategy in the treatment of cancers due to its highly localized specificity to tumors and minimal side effects to normal tissues. However, single phototherapy often causes tumor recurrence which hinders its clinical applications. Therefore, developing a NIR-guided dendritic nanoplatform for improving the phototherapy effect and reducing the recurrence of tumors by synergistic chemotherapy and phototherapy is essential.

Methods

A fluorescent targeting ligand, insisting of ICG derivative cypate and a tumor penetration peptide iRGD (CRGDKGPDC), was covalently combined with PAMAM dendrimer to prepare a single agent-based dendritic theranostic nanoplatform iRGD-cypate-PAMAM-DTX (RCPD).

Results

Compared with free cypate, the resulted RCPD could generate enhanced singlet oxygen species while maintaining its fluorescence intensity and heat generation ability when subjected to NIR irradiation. Furthermore, our in vitro and in vivo therapeutic studies demonstrated that compared with phototherapy or chemotherapy alone, the combinatorial chemo-photo treatment of RCPD with the local exposure of NIR light can significantly improve anti-tumor efficiency and reduce the risk of recurrence of tumors.

Conclusion

The multifunctional theranostic platform (RCPD) could be used as a promising method for NIR fluorescence image-guided combinatorial treatment of tumor cancers.

ROS-responsive targeting micelles for optical imaging-guided chemo-phototherapy of cancer

The combination of chemotherapy and phototherapy gives rise to a boom in cancer therapy methodology. An all-in-one nanoplatform is of particular interest for increased safety and efficacy geared toward personalized precision medicine. However, low drug loading efficiency, random dispersion and distribution without visualization are widespread concerns. Here, a reactive oxygen species (ROS) responsive drug delivery system for imaging-guided chemo-phototherapy was developed. Polymeric micelles were designed and synthesized using PTX (drug) and Cypate (fluorescence and photosensitizer) as hydrophobic segments and PEG as hydrophilic ones encapsulating PTX. Furthermore, folic acid, as a targeting moiety, was conjugated to PEG for directed drug delivery. We evaluated the ROS-responsive drug release profiles and chemo-phototherapy application in an anticancer therapy. The results suggest these biocompatible amphiphilic polymer conjugates would be promising for applications in imaging-guided chemo-phototherapy.

Fluorescence Guidance in Surgical Oncology: Challenges, Opportunities, and Translation

Surgical resection continues to function as the primary treatment option for most solid tumors. However, the detection of cancerous tissue remains predominantly subjective and reliant on the expertise of the surgeon. Surgery that is guided by fluorescence imaging has shown clinical relevance as a new approach to detecting the primary tumor, tumor margins, and metastatic lymph nodes. It is a technique to reduce recurrence and increase the possibility of a curative resection. While significant progress has been made in developing this emerging technology as a tool to assist the surgeon, further improvements are still necessary. Refining imaging agents and tumor targeting strategies to be a precise and reliable surgical strategy is essential in order to translate this technology into patient care settings. This review seeks to provide a comprehensive update on the most recent progress of fluorescence-guided surgery and its translation into the clinic. By highlighting the current status and recent developments of fluorescence image-guided surgery in the field of surgical oncology, we aim to offer insight into the challenges and opportunities that require further investigation.

Bioengineered bacterial vesicles as biological nano-heaters for optoacoustic imaging

Advances in genetic engineering have enabled the use of bacterial outer membrane vesicles (OMVs) to deliver vaccines, drugs and immunotherapy agents, as a strategy to circumvent biocompatibility and large-scale production issues associated with synthetic nanomaterials. We investigate bioengineered OMVs for contrast enhancement in optoacoustic (photoacoustic) imaging. We produce OMVs encapsulating biopolymer-melanin (OMVMel) using a bacterial strain expressing a tyrosinase transgene. Our results show that upon near-infrared light irradiation, OMVMel generates strong optoacoustic signals appropriate for imaging applications. In addition, we show that OMVMel builds up intense heat from the absorbed laser energy and mediates photothermal effects both in vitro and in vivo. Using multispectral optoacoustic tomography, we noninvasively monitor the spatio-temporal, tumour-associated OMVMel distribution in vivo. This work points to the use of bioengineered vesicles as potent alternatives to synthetic particles more commonly employed for optoacoustic imaging, with the potential to enable both image enhancement and photothermal applications.

Biodegradable Micelles for NIR/GSH-Triggered Chemophototherapy of Cancer

The chemotherapy of stimuli-responsive drug delivery systems (SDDSs) is a promising method to enhance cancer treatment effects. However, the low efficiency of chemotherapy drugs and poor degradation partly limit the application of SDDSs. Herein, we report doxorubicin (DOX)-loading mixed micelles for biotin-targeting drug delivery and enhanced photothermal/photodynamic therapy (PTT/PDT). Glutathione (GSH)-responsive mixed micelles were prepared by a dialysis method, proportionally mixing polycaprolactone-disulfide bond-biodegradable photoluminescent polymer (PCL-SS-BPLP) and biotin-polyethylene glycol-cypate (biotin-PEG-cypate). Chemically linking cypate into the mixed micelles greatly improved cypate solubility and PTT/PDT effect. The micelles also exhibited good monodispersity and stability in cell medium (~119.7 nm), low critical micelles concentration, good biodegradation, and photodecomposition. The high concentration of GSH in cancer cells and near-infrared light (NIR)-mediated cypate decomposition were able to achieve DOX centralized release. Meanwhile, the DOX-based chemotherapy combined with cypate-based NIR-triggered hyperthermia and reactive oxygen species could synergistically induce HepG2 cell death and apoptosis. The in vivo experiments confirmed that the micelles generated hyperthermia and achieved a desirable therapeutic effect. Therefore, the designed biodegradable micelles are promising safe nanovehicles for antitumor drug delivery and chemo/PTT/PDT combination therapy.

Carbon dot aggregates as an alternative to gold nanoparticles for the laser-induced opening of microchamber arrays

Carbon dots (CDs) are usually used as an alternative to other fluorescent nanoparticles. Apart from fluorescence, CDs also have other important properties for use in composite materials, first of all their ability to absorb light energy and convert it into heat. In our work, for the first time, CDs have been proposed as an alternative to gold nanostructures for harvesting light energy, which results in the opening of polymer-based containers with biologically active compounds. In this paper, we propose a method for the synthesis of polylactic acid microchamber arrays with embedded CDs. A comparative analysis was made of the damage to microchambers functionalized with gold nanorods and with CD aggregates, depending on the wavelength and power of the laser used. The release of fluorescent cargo from the microchamber arrays with CD aggregates under laser exposure was demonstrated.

Recent progress in the development of near-infrared organic photothermal and photodynamic nanotherapeutics

Phototherapies including photothermal therapy (PTT) and photodynamic therapy (PDT) have gained considerable attention due to their high tumor ablation efficiency, excellent spatial resolution and minimal side effects on normal tissue. In contrast to inorganic nanoparticles, near-infrared (NIR) absorbing organic nanoparticles bypass the issue of metal-ion induced toxicity and thus are generally considered to be more biocompatible. Moreover, with the guidance of different kinds of imaging methods, the efficacy of cancer phototherapy based on organic nanoparticles has shown to be optimizable. In this review, we summarize the synthesis and application of NIR-absorbing organic nanoparticles as phototherapeutic nanoagents for cancer phototherapy. The chemistry, optical properties and therapeutic efficacies of organic nanoparticles are firstly described. Their phototherapy applications are then surveyed in terms of therapeutic modalities, which include PTT, PDT and PTT/PDT combined therapy. Finally, the present challenges and potential of imaging guided PTT/PDT are discussed.

Biotinylated Bilirubin Nanoparticles as a Tumor Microenvironment-Responsive Drug Delivery System for Targeted Cancer Therapy

The tumor microenvironment (TME) plays a crucial role in tumorigenesis and cancer cell metastasis. Accordingly, a drug-delivery system (DDS) that is capable of targeting tumor and releasing drugs in response to TME-associated stimuli should lead to potent antitumor efficacy. Here, a cancer targeting, reactive oxygen species (ROS)-responsive drug delivery vehicle as an example of a TME-targeting DDS is reported. Tumor targeting is achieved using biotin as a ligand for "biotin transporter"-overexpressing malignant tumors, and bilirubin-based nanoparticles (BRNPs) are used as a drug-delivery carrier that enables ROS-responsive drug release. Doxorubicin-loaded, biotinylated BRNPs (Dox@bt-BRNPs) with size of ≈100 nm are prepared by a one-step self-assembly process. Dox@bt-BRNPs exhibit accelerated Dox-release behavior in response to ROS and show specific binding as well as anticancer activity against biotin transporter-overexpressing HeLa cells in vitro. bt-BRNPs labeled with cypate, near-infrared dye, show much greater accumulation at tumor sites in HeLa tumor-bearing mice than BRNPs lacking the biotin ligand. Finally, intravenous injection of Dox@bt-BRNPs into HeLa tumor-bearing mice results in greater antitumor efficacy compared with free Dox, bt-BRNPs only, and Dox@BRNPs without causing any appreciable body weight loss. Collectively, these findings suggest that bt-BRNPs hold potential as a new TME-responsive DDS for effectively treating various tumors.

Polydopamine-Functionalized CA-(PCL-ran-PLA) Nanoparticles for Target Delivery of Docetaxel and Chemo-photothermal Therapy of Breast Cancer

Current limitations of cancer therapy include the lack of effective strategy for target delivery of chemotherapeutic drugs, and the difficulty of achieving significant efficacy by single treatment. Herein, we reported a synergistic chemo-photothermal strategy based on aptamer (Apt)-polydopamine (pD) functionalized CA-(PCL-ran-PLA) nanoparticles (NPs) for effective delivery of docetaxel (DTX) and enhanced therapeutic effect. The developed DTX-loaded Apt-pD-CA-(PCL-ran-PLA) NPs achieved promising advantages, such as (i) improved drug loading content (LC) and encapsulation efficiency (EE) initiated by star-shaped copolymer CA-(PCL-ran-PLA); (ii) effective target delivery of drugs to tumor sites by incorporating AS1411 aptamers; (iii) significant therapeutic efficacy caused by synergistic chemo-photothermal treatment. In addition, the pD coating strategy with simple procedures could address the contradiction between targeting modification and maintaining formerly excellent bio-properties. Therefore, with excellent bio-properties and simple preparation procedures, the DTX-loaded Apt-pD-CA-(PCL-ran-PLA) NPs effectively increased the local drug concentration in tumor sites, minimized side effects, and significantly eliminated tumors, indicating the promising application of these NPs for cancer therapy.

Tantalum Sulfide Nanosheets as a Theranostic Nanoplatform for Computed Tomography Imaging-Guided Combinatorial Chemo-Photothermal Therapy

Near-infrared (NIR)-absorbing metal-based nanomaterials have shown tremendous potential for cancer therapy, given their facile and controllable synthesis, efficient photothermal conversion, capability of spatiotemporal-controlled drug delivery, and intrinsic imaging function. Tantalum (Ta) is among the most biocompatible metals and arouses negligible adverse biological responses in either oxidized or reduced forms, and thus Ta-derived nanomaterials represent promising candidates for biomedical applications. However, Ta-based nanomaterials by themselves have not been explored for NIR-mediated photothermal ablation therapy. In this work, we report an innovative Ta-based multifunctional nanoplatform composed of biocompatible tantalum sulfide (TaS2) nanosheets (NSs) for simultaneous NIR hyperthermia, drug delivery, and computed tomography (CT) imaging. The TaS2 NSs exhibit multiple unique features including (i) efficient NIR light-to-heat conversion with a high photothermal conversion efficiency of 39%. (ii) high drug loading (177% by weight), (iii) controlled drug release triggered by NIR light and moderate acidic pH, (iv) high tumor accumulation via heat-enhanced tumor vascular permeability, (v) complete tumor ablation and negligible side effects, and (vi) comparable CT imaging contrast efficiency to the widely clinically used agent iobitridol. We expect that this multifunctional NS platform can serve as a promising candidate for imaging-guided cancer therapy and selection of cancer patients with high tumor accumulation.

Antimonene Quantum Dots: Synthesis and Application as Near-Infrared Photothermal Agents for Effective Cancer Therapy

Photothermal therapy (PTT) has shown significant potential for cancer therapy. However, developing nanomaterials (NMs)-based photothermal agents (PTAs) with satisfactory photothermal conversion efficacy (PTCE) and biocompatibility remains a key challenge. Herein, a new generation of PTAs based on two-dimensional (2D) antimonene quantum dots (AMQDs) was developed by a novel liquid exfoliation method. Surface modification of AMQDs with polyethylene glycol (PEG) significantly enhanced both biocompatibility and stability in physiological medium. The PEG-coated AMQDs showed a PTCE of 45.5 %, which is higher than many other NMs-based PTAs such as graphene, Au, MoS2 , and black phosphorus (BP). The AMQDs-based PTAs also exhibited a unique feature of NIR-induced rapid degradability. Through both in vitro and in vivo studies, the PEG-coated AMQDs demonstrated notable NIR-induced tumor ablation ability. This work is expected to expand the utility of 2D antimonene (AM) to biomedical applications through the development of an entirely novel PTA platform.