Near infrared dye-conjugated oxidative stress amplifying polymer micelles for dual imaging and synergistic anticancer phototherapy

Prospects of nano-theranostic approaches against breast and cervical cancer

The bottleneck on therapeutics and diagnostics is removed by an alternate approach known as theranostics which combines both therapeutics and diagnostics within a single platform. Due to this "all in one" nature of theranostics, it is now extensively applied in the medicinal field mainly in cancer treatment over the conventional therapy. Recently, FDA approval of lutetium 177 (177Lu) DOTATATE and 177Lu-PSMA-based radionuclide theranostics are clinically used and very few theranostics specific to breast cancer are in clinical trials. In this review, we are willing to draw special attention to the application of theranostics in the most relevant cancers in women, the breast and the cervical as these cancers affect women harshly but talked very silently due to the social restrictions and discriminations mainly in rural areas of developing and under developing countries. This approach not only combines therapeutics and diagnostics but targeting moieties can also be accommodated for the precise medication. Herein, our main objective is to enlighten the broader aspects of different kinds of theranostic devices based on radioisotopes, nanoparticles, graphene quantum dots, dendrimers and their fruitful application against breast and cervical cancer. The development of synthetic nano-theranostics was reported by accommodating therapeutic drugs, imaging probes and targeting ligands through conjugation or encapsulation. The imaging modalities like optical fluorescence, photosensitizers and radiotracers are used to get the diagnostic images through NIR, PET, MRI and CT/SPECT to detect the progress of cancer non-invasively and also at the same time targeting ligands such as antibodies, proteins and peptides in attachment with the theranostics enhances the therapeutic efficacy in addition to the clarity in diagnostics. The applications of theranostics from the last decade with their present scenario in clinics and future perspectives, as well as the pitfalls with the hurdles that still leave questions to rethink from the root are also been discussed in this review.

Fluorogenic In Situ Thioacetalization: Expanding the Chemical Space of Fluorescent Probes, Including Unorthodox, Bifurcated, and Mechanosensitive Chalcogen Bonds

Progress with fluorescent flippers, small-molecule probes to image membrane tension in living systems, has been limited by the effort needed to synthesize the twisted push-pull mechanophore. Here, we move to a higher oxidation level to introduce a new design paradigm that allows the screening of flipper probes rapidly, at best in situ. Late-stage clicking of thioacetals and acetals allows simultaneous attachment of targeting units and interfacers and exploration of the critical chalcogen-bonding donor at the same time. Initial studies focus on plasma membrane targeting and develop the chemical space of acetals and thioacetals, from acyclic amino acids to cyclic 1,3-heterocycles covering dioxanes as well as dithiolanes, dithianes, and dithiepanes, derived also from classics in biology like cysteine, lipoic acid, asparagusic acid, DTT, and epidithiodiketopiperazines. From the functional point of view, the sensitivity of membrane tension imaging in living cells could be doubled, with lifetime differences in FLIM images increasing from 0.55 to 1.11 ns. From a theoretical point of view, the complexity of mechanically coupled chalcogen bonding is explored, revealing, among others, intriguing bifurcated chalcogen bonds.

Tumor-targeted redox-regulating and antiangiogenic phototherapeutics nanoassemblies for self-boosting phototherapy

Cancer cells are equipped with abundant antioxidants such as glutathione (GSH) that eliminate reactive oxygen species (ROS) to deteriorate the therapeutic efficacy of photodynamic therapy (PDT). Another challenge in PDT is circumventing PDT-induced hypoxic condition that provokes upregulation of pro-angiogenic factor such as vascular endothelial growth factor (VEGF). It is therefore reasonable to expect that therapeutic outcomes of PDT could be maximized by concurrent delivery of photosensitizers with GSH depleting agents and VEGF suppressors. To achieve cooperative therapeutic actions of PDT with in situ GSH depletion and VEGF suppression, we developed tumor targeted redox-regulating and antiangiogenic phototherapeutic nanoassemblies (tRAPs) composed of self-assembling disulfide-bridged borylbenzyl carbonate (ssBR), photosensitizer (IR780) and tumor targeting gelatin. As a framework of tRAPs, ssBR was rationally designed to form nanoconstructs that serve as photosensitizer carriers with intrinsic GSH depleting- and VEGF suppressing ability. tRAPs effectively depleted intracellular GSH to render cancer cells more vulnerable to ROS and also provoked immunogenic cell death (ICD) of cancer cells upon near infrared (NIR) laser irradiation. In mouse xenograft models, tRAPs preferentially accumulated in tumors and dramatically eradicated tumors with laser irradiation. The design rationale of tRAPs provides a simple and versatile strategy to develop self-boosting phototherapeutic agents with great potential in targeted cancer therapy.

Cinnamaldehyde-Contained Polymers and Their Biomedical Applications

Cinnamaldehyde, a natural product that can be extracted from a variety of plants of the genus Cinnamomum, exhibits excellent biological activities including antibacterial, antifungal, anti-inflammatory, and anticancer properties. To overcome the disadvantages (e.g., poor water solubility and sensitivity to light) or enhance the advantages (e.g., high reactivity and promoting cellular reactive oxygen species production) of cinnamaldehyde, cinnamaldehyde can be loaded into or conjugated with polymers for sustained or controlled release, thereby prolonging the effective action time of its biological activities. Moreover, when cinnamaldehyde is conjugated with a polymer, it can also introduce environmental responsiveness to the polymer through the form of stimuli-sensitive linkages between its aldehyde group and various functional groups of polymers. The environmental responsiveness provides the great potential of cinnamaldehyde-conjugated polymers for applications in the biomedical field. In this review, the strategies for preparing cinnamaldehyde-contained polymers are summarized and their biomedical applications are also reviewed.

Dual-Site Chemosensor for Monitoring ·OH-Cysteine Redox in Cells and In Vivo

The reaction between hydroxyl radical (^·OH) and cysteine (Cys) plays an important role in the redox balance of living cells. A deeper insight into this intracellular reaction modulation and process is necessary and draws great interest. A highly effective technique consists of the real-time visualization of the two bioactive species and the perception of their respective changes by using a fluorescent probe. In this study, a dual-site chemosensor SPI based on phenothiazine-cyanine was developed, which realized quantitative detection and real-time imaging of ^·OH and Cys at their own fluorescence channels (^·OH: λ_ex = 485 nm, λ_em = 608 nm; Cys: λ_ex = 426 nm, λ_em = 538 nm) without spectral crosstalk. The fluorescent sensor showed excellent anti-interference and selectivity for common biological substances, apart from the successful imaging of exogenous and endogenous ^·OH and Cys. We further visualized the redox dynamic reaction and explored the correlation of ^·OH and Cys generated by different inhibitors (sulfasalazine and (1S, 3R)-RSL3). Notably, the chemosensor also possesses the capacity to clearly monitor ^·OH and Cys in living mice and zebrafish. This study reports on the first chemosensor to investigate the process of intracellular redox modulation and control between ^·OH and Cys, which show potential to further explore some metabolic and physiological mechanisms.

Tumor-Targeted Polydopamine-Based Nanoparticles for Multimodal Mapping Following Photothermal Therapy of Metastatic Lymph Nodes

PURPOSE

Lymphadenectomy with lymph node (LN) mapping is essential for surgical removal of solid tumors. Existing agents do not provide accurate multimodal mapping and antitumor therapy for metastatic LNs; therefore, we fabricated a polydopamine (PDA) nanoparticle (NP)-based tumor-targeted LN mapping agent capable of multimodal mapping and guided photothermal therapy (PTT) for metastatic LNs.

MATERIALS AND METHODS

PDA NPs modified with polyethylene glycol (PEG) were obtained by polymerization under alkaline conditions. The PEG-PDA NPs were loaded with the circular tripeptide Arg-Gly-Asp (cRGD) to achieve tumor-targeting capacity and with the fluorescent dye IR820 and magnetic resonance imaging (MRI) contrast Gd(NH2)2 for in situ detection. The resulting cRGD-PEG-PDA@IR820/Gd(NH2)2 (cRGD-PPIG) NPs were tested for their biosafety and metastatic LN mapping ability. They were drained specifically into LNs and selectively taken up by gastric MKN45 cells via αvβ3 integrin-mediated endocytosis.

RESULTS

This phenomenon enabled MR/optical/near-infrared fluorescence multimodal metastatic LN mapping, guiding the creation of accurate and highly efficient PTT for gastric cancer metastatic LNs in mice.

CONCLUSION

In summary, we fabricated tumor-targeted cRGD-PPIG NPs with MR/optical/near-infrared fluorescence multimodal metastatic LN mapping capacity for surgery and efficient PTT guidance post-surgery.

Self-deliverable and self-immolative prodrug nanoassemblies as tumor targeted nanomedicine with triple cooperative anticancer actions

Stimulus-responsive self-assembling prodrug-based nanomedicine has emerged as a novel paradigm in controlled drug delivery. All-trans retinoic acid (RA), one of vitamin A metabolites, induces apoptotic cancer cell death, but its clinical applications are limited by weak anticancer efficacy. To fully maximize the therapeutic potential of RA, we exploited the unique chemistry of arylboronic acid which undergoes hydrogen peroxide (H2O2)-triggered degradation to release quinone methide (QM) that alkylates glutathione (GSH) to disrupt redox homeostasis and is also converted into hydroxybenzyl alcohol (HBA) to suppress the expression of vascular endothelial growth factor (VEGF). Here, we report that boronated retinoic acid prodrug (RABA) can be formulated into self-deliverable nanoassemblies which release both RA and QM in a H2O2-triggered self-immolative manner to exert cooperative anticancer activities. RABA nanoassemblies exert anticancer effects by inducing reactive oxygen species (ROS)-mediated apoptosis, eliciting immunogenic cell death (ICD) and suppressing angiogenic VEGF expression. The excellent anticancer efficacy of RABA nanoassemblies can be explained by benefits of self-assembling prodrug-based drug self-delivery and cooperative anticancer actions. The design strategy of RABA would provide a new insight into the rational design of self-deliverable and self-immolative boronated prodrug nanoassemblies for targeted cancer therapy.

Precise control over the silica shell thickness and finding the optimal thickness for the peak heat diffusion property of AuNR@SiO2

Silica-coated gold nanorods (AuNRs) exhibit significantly enhanced photothermal effects and photoacoustic (PA) signal intensities, which is beneficial for various nanophotonic applications in materials science. However, the silica shell thickness for optimum enhancement is not fully understood and is even controversial depending on the physical state of the silica shell. This is because of the lack of systematic investigations of the nanoscale silica shell thickness and the photothermal effect. This study provides a robust synthetic method to control the silica shell thickness at the nanoscale and the physical state-dependent heat diffusion property. The selected base and solvent system enabled the production of silica-coated AuNRs (AuNR@SiO₂) with silica shell thicknesses of 5, 10, 15, 20, 25, 30, 35, and 40 nm. AuNRs with a 20 nm silica shell showed the highest photothermal effect with a 1.45-times higher photothermal efficiency than that of AuNRs without a silica shell. The low density of the silica shell on the AuNRs showed a low photothermal effect and photostability. It was found that the disruption of cetyltrimethyl ammonium bromide (CTAB) layers on the AuNRs was responsible for the low photostability of the AuNRs. The simulation study for the heat diffusion property showed facilitated heat diffusion in the presence of a 20 nm silica shell. In a cell-based study, AuNRs with a 20 nm silica shell showed the most sensitive photothermal effect for cell death. The results of this robust study can provide conclusive conditions for the optimal silica shell thickness to obtain the highest photothermal effect, which will be useful for the future design of nanomaterials in various fields of application.

An Edaravone-Guided Design of a Rhodamine-Based Turn-on Fluorescent Probe for Detecting Hydroxyl Radicals in Living Systems

The hydroxyl radical (·OH), one of the reactive oxygen species (ROS) in biosystems, is found to be involved in many physiological and pathological processes. However, specifically detecting endogenous ·OH remains an outstanding challenge owing to the high reactivity and short lifetime of this radical. Herein, inspired by the scavenging mechanism of a neuroprotective drug edaravone toward ·OH, we developed a new ·OH-specific fluorescent probe RH-EDA. RH-EDA is a hybrid of rhodamine and edaravone and exploits a ·OH-specific 3-methyl-pyrazolone moiety to control its fluorescence behavior. RH-EDA itself is almost nonfluorescent in physiological conditions, which was attributed to the formation of a twisted intramolecular charge transfer (TICT) state upon photoexcitation and the acylation of its rhodamine nitrogen at the 3' position. However, upon a treatment with ·OH, its edaravone subunit was converted to the corresponding 2-oxo-3-(phenylhydrazono)-butanoic acid (OPB) derivative (to afford RH-OPB), thus leading to a significant fluorescence increase (ca. 195-fold). RH-EDA shows a high sensitivity and selectivity to ·OH without interference from other ROS. RH-EDA has been utilized for imaging endogenous ·OH production in living cells and zebrafishes under different stimuli. Moreover, RH-EDA allows a high-contrast discrimination of cancer cells from normal ones by monitoring their different ·OH levels upon stimulation with β-Lapachone (β-Lap), an effective ROS-generating anticancer therapeutic agent. The present study provides a promising methodology for the construction of probes through a drug-guided approach.

Preclinical Cancer Theranostics—From Nanomaterials to Clinic: The Missing Link

Nanomaterials with cancer‐imaging and therapeutic properties have emerged as the principal focus of nanotheranostics. The past decade has experienced a significant increase in research in the design, formulation, and preclinical and clinical trials of theranostic nanosystems. However, current theranostic nanoformulations have yet to be approved by the FDA for clinical use. Consequently, the present review focuses on the importance of the careful examination of the in vivo preclinical status of specific nanotheranostic materials as a prerequisite for their clinical translation. The scope of coverage is structured according to all of the major organic, inorganic, 2D, and hybrid nanotheranostic materials and their in vivo preclinical status. The therapeutic advantages and limitations of these materials in animal models are considered and the various strategies to enhance the biocompatibility of theranostic nanoparticles are summarized.

Acid-responsive endosomolytic polymeric nanoparticles with amplification of intracellular oxidative stress for prodrug delivery and activation

Prodrug strategy especially in the field of chemotherapy of cancers possesses significant advantages reducing the side toxicity of anticancer drugs. However, high-efficiency delivery and in situ activation of prodrugs for tumor growth suppression are still a great challenge. Herein, we report rationally engineered pH-responsive endosomolytic polymeric micelles for the delivery of an oxidation-activable prodrug into the cytoplasm of cancer cells and amplification of intracellular oxidative stress for further prodrug activation. The prepared block copolymers consist of a poly(ethylene glycol) (PEG) block and a segment grafted by endosomolytic moieties and acetal linkage-connected cinnamaldehyde groups. The amphiphilic diblock copolymers can self-assemble to form micelles in water for loading the oxidation-activable phenylboronic pinacol ester-caged camptothecin prodrug (ProCPT). The obtained micelles can release free cinnamaldehyde under acidic conditions in tumor tissues and endo/lysosomes followed by efficient endosomal escape, which further induces enhancement of intracellular reactive oxygen species (ROS) to activate the prodrugs. Simultaneously, intracellular glutathione (GSH) can be reduced by quinone methide that was produced during prodrug activation. The ProCPT-loaded micelles can finally achieve efficient tumor accumulation and retention as well as effective tumor growth inhibition. More importantly, hematological and pathological analysis of toxicity reveals that the ProCPT-loaded micelles do not cause obvious toxic side effects toward important organs of mice. A positive immunomodulatory microenvironment in tumor tissue and serum can be detected after treatment with ProCPT-loaded micelles. Therefore, the endosomolytic ProCPT-loaded micelles exert synergistic therapeutic effects toward tumors through amplification of intracellular oxidative stress and activation of the prodrugs.

Tumor-Targeting H2O2-Responsive Photosensitizing Nanoparticles with Antiangiogenic and Immunogenic Activities for Maximizing Anticancer Efficacy of Phototherapy

Phototherapy including photothermal therapy (PTT) and photodynamic therapy (PDT) uses photosensitizers and light to kill cancer cells and has become a promising therapeutic modality because of advantages such as minimal invasiveness and high cancer selectivity. However, PTT or PDT as a single treatment modality has insufficient therapeutic efficacy. Moreover, oxygen consumption by PDT activates angiogenic factors and leads to cancer recurrence and progression. Therefore, the therapeutic outcomes of phototherapy would be maximized by employing photosensitizers for concurrent PTT and PDT and suppressing angiogenic factors. Therefore, integrating photosensitive agents and antiangiogenic agents in a single nanoplatform would be a promising strategy to maximize the therapeutic efficacy of phototherapy. In this study, we developed hyaluronic acid-coated fluorescent boronated polysaccharide (HA-FBM) nanoparticles as a combination therapeutic agent for phototherapy and antiangiogenic therapy. Upon a single near-infrared laser irradiation, HA-FBM nanoparticles generated heat and singlet oxygen simultaneously to kill cancer cells and also induced immunogenic cancer cell death. Beside their fundamental roles as photosensitizers, HA-FBM nanoparticles exerted antiangiogenic effects by suppressing the vascular endothelial growth factor (VEGF) and cancer cell migration. In a mouse xenograft model, intravenously injected HA-FBM nanoparticles targeted tumors by binding CD44-overexpressing cancer cells and suppressed angiogenic VEGF expression. Upon laser irradiation, HA-FBM nanoparticles remarkably eradicated tumors and increased anticancer immunity. Given their synergistic effects of phototherapy and antiangiogenic therapy from tumor-targeting HA-FBM nanoparticles, we believe that integrating the photosensitizers and antiangiogenic agents into a single nanoplatform presents an attractive strategy to maximize the anticancer therapeutic efficacy of phototherapy.

pH-Responsive Amphiphilic Polyether Micelles with Superior Stability for Smart Drug Delivery

Despite widespread interest in the amphiphilic polymeric micelles for drug delivery systems, it is highly desirable to achieve high loading capacity and high efficiency to reduce the side effects of therapeutic agents while maximizing their efficacy. Here, we present a novel hydrophobic epoxide monomer, cyclohexyloxy ethyl glycidyl ether (CHGE), containing an acetal group as a pH-responsive cleavable linkage. A series of its homopolymers, poly(cyclohexyloxy ethyl glycidyl ether)s (PCHGEs), and block copolymers, poly(ethylene glycol)-block-poly(cyclohexyloxy ethyl glycidyl ether)s (mPEG-b-PCHGE), were synthesized via anionic ring-opening polymerization in a controlled manner. Subsequently, the self-assembled polymeric micelles of mPEG-b-PCHGE demonstrated high loading capacity, excellent stability in biological media, tunable release efficiency, and high cell viability. Importantly, quantum mechanical calculations performed by considering prolonged hydrolysis of the acetal group in CHGE indicated that the CHGE monomer had higher hydrophobicity than three other functional epoxide monomer analogues developed. Furthermore, the preferential cellular uptake and in vivo therapeutic efficacy confirmed the enhanced stability and the pH-responsive degradation of the amphiphilic block copolymer micelles. This study provides a new platform for the development of versatile smart polymeric drug delivery systems with high loading efficiency and tailorable release profiles.

880 nm NIR-Triggered Organic Small Molecular-Based Nanoparticles for Photothermal Therapy of Tumor

Photothermal therapy (PTT) has received constant attention as an efficient cancer therapy method due to locally selective treatment, which is not affected by the tumor microenvironment. In this study, a novel 880 nm near-infrared (NIR) laser-triggered photothermal agent (PTA), 3TT-IC-4Cl, was used for PTT of a tumor in deep tissue. Folic acid (FA) conjugated amphiphilic block copolymer (folic acid-polyethylene glycol-poly (β-benzyl-L-aspartate)₁₀, FA-PEG-PBLA₁₀) was employed to encapsulate 3TT-IC-4Cl by nano-precipitation to form stable nanoparticles (TNPs), and TNPs exhibit excellent photothermal stability and photothermal conversion efficiency. Furthermore, the in vitro results showed TNPs display excellent biocompatibility and significant phototoxicity. These results suggest that 880 nm triggered TNPs have great potential as effective PTAs for photothermal therapy of tumors in deep tissue.

An "all-in-one" strategy based on the organic molecule DCN-4CQA for effective NIR-fluorescence-imaging-guided dual phototherapy

Dual phototherapy combining photodynamic therapy (PDT) and photothermal therapy (PTT) is considered to be a more effective therapeutic method against cancer than single treatment. Therefore, the development of a single material with both near-infrared (NIR)-laser-triggered PDT and PTT abilities is highly desirable but remains a great challenge. A design philosophy for photosensitizers for integrated PDT and PTT treatment has been put forward: (1) a high molar extinction coefficient in the NIR region; (2) suitable LUMO and T1 energy levels to regulate intersystem crossing for effective singlet oxygen (1O2) generation for PDT; and (3) the suppression of fluorescence emission to enhance the process of nonradiative transition with appropriate chemical modifications. Herein, an "all-in-one" functional material, di-cyan substituted 5,12-dibutylquinacridone (DCN-4CQA), for diagnosis and therapy was obtained. DCN-4CQA possesses dual-functional phototherapeutic activity and NIR fluorescence and it was produced via a facile synthesis process from the classic organic photoelectric material quinacridone. We then prepared smart water-soluble nanoparticles (NPs), DCN-4CQA/F127, using Pluronic® 127 (F127) as a drug carrier. The NPs exhibited excellent biocompatibility, robust photostability, NIR fluorescence, a high photothermal conversion efficiency (η = 47.3%), and sufficient 1O2 generation (ΦΔ = 24.3%) under NIR laser irradiation. Remarkably, the DCN-4CQA/F127 NPs significantly inhibited tumor growth in mice subjected to NIR laser irradiation. This study provides a new route for the development of highly efficient, low-cytotoxicity photosensitizers for fluorescence-imaging-guided PTT/PDT.

Construction of biodegradable core cross-linked nanoparticles from near infrared dyes encoded in polyprodrug amphiphiles and investigation of their synergistic anticancer activity

Amphiphilic polyprodrugs with reduction-responsive camptothecin prodrug and photothermal converted IR780 dyes was performed via core cross-linking protocol. The nanoparticles could be served as a nanocarrier and presented severe cytotoxicity to HeLa cells.

Zoledronate and SPIO dual-targeting nanoparticles loaded with ICG for photothermal therapy of breast cancer tibial metastasis

Currently, nanoparticles (NPs) for cancer photothermal therapy (PTT) have limited in vivo clearance, lack targeting ability and have unsatisfactory therapeutic efficiency. Herein, we report a dual-targeting and photothermally triggered nanotherapeutic system based on superparamagnetic iron oxide (Fe3O4) and indocyanine green (ICG)-entrapped poly-lactide-co-glycolide modified by ZOL (PLGA-ZOL) NPs (ICG/Fe3O4@PLGA-ZOL) for PTT of breast cancer tibial metastasis, which occurs frequently in the clinic and causes challenging complications in breast cancer. In this system, both ICG and Fe3O4 can convert light into heat, while NPs with Fe3O4 and ZOL can be attracted to a specific location in bone under an external magnetic field. Specifically, the dual-targeting and double photothermal agents guaranteed high accumulation in the tibia and perfect PTT efficiency. Furthermore, the in vivo studies showed that ICG/Fe3O4@PLGA-ZOL NPs have extraordinary antitumor therapeutic effects and that these NPs can be accurately located in the medullary cavity of the tibia to solve problems with deep lesions, such as breast cancer tibial metastasis, showing great potential for cancer theranostics.

Chitosan based pH-responsive polymeric prodrug vector for enhanced tumor targeted co-delivery of doxorubicin and siRNA

The co-delivery of chemotherapeutic drugs and siRNA has gained increasing attentions owing to the enhanced antitumor efficacy over single administration. In this work, a chitosan-based pH-responsive prodrug vector was developed for the co-delivery of doxorubicin (DOX) and Bcl-2 siRNA. The accumulation of fabricated nanoparticles in hepatoma cells was enhanced by glycyrrhetinic acid receptor-mediated endocytosis. The cumulative release amount of the encapsulated DOX and siRNA reached 90.2 % and 81.3 % in 10 h, respectively. More strikingly, this nanoplatform can efficiently integrate gene- and chemo-therapies with a dramatically enhanced tumor inhibitory rate (88.0 %) in vivo. This co-delivery system may provide the latest strategy to meet the needs of combination therapies for tumors, offering safe and efficient improvements to the synergistic antitumor efficacy of gene-chemotherapies.

One Stone Two Birds: Zr-Fc Metal-Organic Framework Nanosheet for Synergistic Photothermal and Chemodynamic Cancer Therapy

Metal-organic frameworks (MOFs) have been identified as promising materials for the delivery of therapeutics to cure cancer owing to their intrinsic porous structure. However, in a majority of cases, MOFs act as only a delivery cargo for anticancer drugs while little attention has been focused on the utilization of their intriguing physical and chemical properties for potential anticancer purposes. Herein for the first time, an ultrathin (16.4 nm thick) ferrocene-based MOF (Zr-Fc MOF) nanosheet has been synthesized for synergistic photothermal therapy (PTT) and Fenton reaction-based chemodynamic (CDT) therapy to cure cancer without additional drugs. The Zr-Fc MOF nanosheet acts not only as an excellent photothermal agent with a prominent photothermal conversion efficiency of 53% at 808 nm but also as an efficient Fenton catalyst to promote the conversion of H₂O₂ into hydroxyl radical (^•OH). As a consequence, an excellent therapeutic performance has been achieved in vitro as well as in vivo through this combinational effect. This work aims to construct an "all-in-one" MOF nanoplatform for PTT and CDT treatments without incorporating any additional therapeutics, which may launch a new era in the investigation of MOF-based synergistic therapy platforms for cancer therapy.

Curcuminoids encapsulated liposome nanoparticles as a blue light emitting diode induced photodynamic therapeutic system for cancer treatment

Unlike normal cells, cancer cells mutate to thrive in exaggerated levels of reactive oxygen species (ROS). This potentially makes them more susceptible to small molecule-induced oxidative stress. The intracellular ROS increase in cancer cells is a potential area under investigation for the development of cancer therapeutics targeting cancer cells. Visible photons of 430-490 nm wavelengths from a blue-light emitting diode (BLED) encompass the visible region of the spectrum known to induce ROS in cancer cells. Curcuminoids (CUR) naturally occurring photosensitizers sensitized by the blue wavelength of the visible light, well known for its potent anti-inflammatory and anticancer activity. Poor solubility and bioavailability, of the compound of the small molecule CUR restrict the therapeutic potential and limits CUR to be used as a photosensitizer. Here, our research group reports the use of small molecules CUR, encapsulated in liposome nanocarriers (LIP-CUR) coupled with blue light-emitting diode (BLED) induced photodynamic therapy (BLED-PDT). In A549 cancer cells in vitro, LIP-CUR coupled with BLED initiated BLED-PDT and triggered ¹O₂, ultimately resulting in caspase-3 activated apoptotic cell death. The combination of a non-cytotoxic dose of small molecule CUR co-treated with BLED to trigger BLED-PDT could be translated and be developed as a novel strategy for the treatment of cancer.

Multifunctional materials conjugated with near-infrared fluorescent organic molecules and their targeted cancer bioimaging potentialities

Near-infrared fluorescent dyes based on small organic molecules are believed to have a great influence on cancer diagnosis at large and targeted cancer cell bioimaging, in particular. NIR dyes-based organic molecules have notable characteristics features, such as high tissue penetration and low tissue autofluorescence in the NIR spectral region. Cancer targeted bioimaging relies significantly on the synthesis of highly specific molecular probes with excellent stability. Recently, NIR dyes have emerged as unique fluorescent probes for cancer bioimaging. These current advancements have overcome many limitations of conventional NIR probes e.g., poor photostability and hydrophilicity, insufficient stability and low quantum yield. The further potential lies in NIR dyes or NIR dyes-coated nanocarriers conjugated with cancer-specific ligand (e.g., peptides, antibodies, proteins or other small molecules). Multifunctional NIR dyes have synthesized, which efficiently accumulate in cancer cells without requiring chemical conjugation and also these dyes have presented novel photophysical and pharmaceutical properties for in vivo imaging. This review highlights the recently developed NIR dyes with novel applications in cancer bioimaging. We believe that these novel fluorophores will enhance our understanding of cancer imaging and pave a new road in cancer diagnosis and treatment.

Multifunctional phototheranostic nanomedicine for cancer imaging and treatment

Cancer, as one of the most life-threatening diseases, shows a high fatality rate around the world. When improving the therapeutic efficacy of conventional cancer treatments, researchers also conduct extensive studies into alternative therapeutic approaches, which are safe, valid, and economical. Phototherapies, including photodynamic therapy (PDT) and photothermal therapy (PTT), are tumor-ablative and function-reserving oncologic interventions, showing strong potential in clinical cancer treatment. During phototherapies, the non-toxic phototherapeutic agents can be activated upon light irradiation to induce cell death without causing much damage to normal tissues. Besides, with the rapid development of nanotechnology in the past decades, phototheranostic nanomedicine also has attracted tremendous interests aiming to continuously refine their performance. Herein, we reviewed the recent progress of phototheranostic nanomedicine for improved cancer therapy. After a brief introduction of the therapeutic principles and related phototherapeutic agents for PDT and PTT, the existing works on developing of phototheranostic nanomedicine by mainly focusing on their categories and applications, particularly on phototherapy-synergized cancer immunotherapy, are comprehensively reviewed. More importantly, a brief conclusion and future challenges of phototheranostic nanomedicine from our point of view are delivered in the last part of this article.

Multistep Consolidated Phototherapy Mediated by a NIR-Activated Photosensitizer

The multifunctional effect of a single molecule for therapeutic functionalities on a single theranostic nanosystem has a great significance to enhance the accuracy of diagnosis and improve the efficacy of therapy. Herein, a biocompatible multistep phototherapeutic system (Ppa-Cy7-PEG-biotin) that contains a photosensitizer pyropheophorbide A (Ppa) with the covalent conjunction of a near-infrared (NIR) cyanine dye (Cy7) was successfully fabricated and functionalized with biotin for flexible specific tumor-targeting phototherapy. These theranostic micelles will disaggregate after NIR irradiation via the photodegradation of cyanine accompanied by the photothermal conversion and the optically controlled release for the restoration of photodynamic function of quenched Ppa. Consecutively, promoted treatments of photosensitive molecules greatly prolonged the tumor retention time and treatment efficiency, having a multistep antitumor effect both in vitro and in vivo. Different from the simple phototherapeutic configurations that only act on the superficial areas of tumors at mild doses, the multistep therapy can be competent for broadly damaging the superficial and deeper regions of tumors at the same dose. Therefore, as opposed to the general combination phototherapeutic approach, this strategy presents a photoactivation-based multistep phototheranostic platform with an enormous potential in enhanced combined phototherapy for cancer.

Nanobiomaterials: from 0D to 3D for tumor therapy and tissue regeneration

Nanobiomaterials have attracted tremendous attention in the biomedical field. Especially in the past few years, a large number of low dimensional nanobiomaterials, including 0D nanostructures, 1D nanotubes and 2D nanosheets, were employed for tumor therapy due to their optically triggered tumor therapy effects and drug loading capacities. However, these low dimensional nanobiomaterials cannot support cell adhesion and possess poor tissue regeneration ability, thus they are not suitable for application in regenerative medicine. Three dimensional (3D) nanofiber scaffolds have attracted extensive attention in tissue regeneration, including bone, skin, nerve and cardiac tissues, due to their similar extracellular matrix structures. Additionally, many 3D scaffolds displayed bone and cartilage regeneration abilities. Therefore, to obtain materials with both tumor therapy and tissue regeneration abilities, it is meaningful and necessary to develop 3D nanobiomaterials with multifunctions. In this review, we systematically review the research progress of nanobiomaterials with varied dimensional structures including 0D, 1D, 2D and 3D, as well as evolutional functions from single tumor therapy to simultaneous tumor therapy and tissue regeneration. This review may pave the way for developing an interdisciplinary research of nanobiomaterials in combination of tumor therapy and regenerative medicine.

Construction of a Polypyrrole-Based Multifunctional Nanocomposite for Dual-Modal Imaging and Enhanced Synergistic Phototherapy against Cancer Cells

Design and construction of multifunctional theranostic nanoplatforms are still desired for cancer-effective treatment. Herein, a kind of polypyrrole (PPy)-based multifunctional nanocomposite was designed and successfully constructed for dual-model imaging and enhanced synergistic phototherapy against cancer cells. Through graphene oxide (GO) sheet coating, PPy nanoparticles (NPs) were effectively combined with polyethylene glycol chains, Au NPs, and IR820 molecules. The obtained PGPAI NPs showed promising ability for photoacoustic/computed tomography imaging. Under near-infrared light irradiation, the PPy core and IR820 molecule effectively generated heat and reactive oxygen species (ROS), respectively. Furthermore, the loaded Au NPs owning catalase-like activity produced oxygen by decomposing H₂O₂ (up-regulated in tumor region), enhancing the oxygen-dependent photodynamic therapy efficacy. The formed PGPAI NPs were also proved to own desirable photothermal conversion efficiency, photothermal stability, colloidal stability, cytocompatibility, and cellular internalization behaviors. Furthermore, cell assay demonstrated that PGPAI NPs displayed enhanced synergistic phototherapy efficacy against cancer cells. These developed multifunctional nanoplatforms are promising for effective cancer theranostic applications.

Poly(β-Amino Esters): Synthesis, Formulations, and Their Biomedical Applications

Poly(β-amino ester) (abbreviated as PBAE or PAE) refers to a polymer synthesized from an acrylate and an amine by Michael addition and has properties inherent to tertiary amines and esters, such as pH responsiveness and biodegradability. The versatility of building blocks provides a library of polymers with miscellaneous physicochemical and mechanical properties. When used alone or together with other materials, PBAEs can be fabricated into different formulations in order to fulfill various requirements in drug delivery (for instance, gene, anticancer drugs, and antimicrobials delivery) and natural complex mimicry (nanochaperones). This progress report discusses the recent developments in design, synthesis, formulations, and applications of PBAEs in biomedical fields and provides a perspective view for the future of the PBAEs.

AIEgen functionalized inorganic–organic hybrid nanomaterials for cancer diagnosis and therapy

AIEgen functionalized inorganic–organic hybrid nanomaterials with multifunctions can be used for cancer diagnosis and imaging-guided synergistic therapy.

Polymeric Ionic Liquid-Based Fluorescent Amphiphilic Block Copolymer Micelle for Selective and Sensitive Detection of p-Phenylenediamine

A highly sensitive and selective detection of p-phenylenediamine (PPD) is achieved by a fluorescence sensor, which is constructed by encapsulating the hydrophobic fluorescent 1-pyrenecarboxaldehyde (Py-CHO) into a polymeric ionic liquid (PIL)-based amphiphilic block copolymer (BCP) micelle. The amine-aldehyde condensation reaction between PPD and Py-CHO leads to the fluorescence quenching of Py-CHO, giving rise to the basis for the quantitative detection of PPD. The core cavity of the micelle formed by the self-assembly of PIL provides an excellent hydrophobic environment for the accommodation of fluorescent Py-CHO, offering significant improved sensitivity and selectivity for PPD detection. The amount of PIL in fabricating the amphiphilic BCP micelle, the BCP-Py-CHO micelle concentration, and the detection pH condition are investigated to obtain the best performance of this sensor. The accurate detection of PPD is achieved in the range of 0.02-10 μmol L^-1 under optimal conditions, and the detection limit is 0.007 μmol L^-1 (3σ/ s). The developed sensor is successfully applied to the determination of PPD contents in hair dyes, spiked water, and urine samples.

Dual Imaging-Guided Oxidative-Photothermal Combination Anticancer Therapeutics

Heme oxygenase-1 (HO-1) is a stress-response protein with potent cytoprotective and antioxidant activity, and its expression in cancer cells is enhanced in response to chemotherapy and radiotherapy. HO-1 is known to serve as a shield to protect cancer cells from anticancer therapy and attenuate apoptotic signals. It can be therefore reasoned that inhibition of HO-1 reduces the antioxidant level, making cancer cells more sensitive to photothermal heating. In this work, we developed dual imaging-guided oxidative-photothermal combination nanotherapeutics (OPCN) consisting of amphiphilic polymers conjugated with zinc protoporphyrin as a HO-1 inhibitor and fluorescent IR820 as a photothermal agent. A combination of OPCN and near-infrared (NIR) laser irradiation markedly increased the temperature and exerted significant toxicity through induction of apoptosis. In a mouse model of xenografts, tumors were identified by the strong fluorescence and photoacoustic signals. OPCN combined with NIR laser irradiation resulted in effective and complete thermal ablation of tumors without discernable side effects and tumor recurrence. We believe that OPCN hold tremendous translational potential for dual imaging-guided oxidative-photothermal combination anticancer therapy.

A tumor treatment strategy based on biodegradable BSA@ZIF-8 for simultaneously ablating tumors and inhibiting infection

Studies have shown a clear correlation between cancer incidence and infection, and cancer treatment can also trigger infection so as to lead to an inflammatory response. In this case, we have designed a new tumor treatment strategy based on biodegradable BSA@ZIF-8 for simultaneously ablating tumors and inhibiting infection. This biodegradable ZIF contains abundant porous structures, showing increased absorption of ions and inelastic collisions. A large amount of frictional heat produced by the collisions results in increased tumor cell death under microwave irradiation. This can effectively inhibit tumor growth in mice by microwave ablation with a good anti-tumor effect (95.4%). Intriguingly, the Zn²⁺ released from the degradation of BSA@ZIF-8 causes damage to bacterial cell walls, and destruction of the metabolism and structure of the membrane, leading to bacterial cell death, and ultimately achieving good antibacterial properties. Moreover, BSA@ZIF-8 is biodegradable without long-term toxicity in vivo. The in vivo experimental results show that BSA@ZIF-8 can protect 80% of the mice from lethal challenge with tumors and the accompanying infection. Overall, we present a novel strategy using biodegradable ZIFs for microwave ablation therapy with simultaneous antibacterial and anti-infection effects for the first time, which has achieved good tumor treatment outcomes.

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.

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.

Polymer ligand-assisted fabrication of multifunctional and redox-responsive self-assembled magnetic nanoclusters for bimodal imaging and cancer treatment

We designed multifunctional magnetic nanoclusters, which can serve as bimodal imaging probes for the detection of solid tumors and act as emerging PDT agents to suppress tumor growth.