Novel phthalocyanine-based polymeric micelles with high near-infrared photothermal conversion efficiency under 808 nm laser irradiation for in vivo cancer therapy

CDs-ICG@BSA nanoparticles for excellent phototherapy and in situ bioimaging

For the diagnosis and treatment of cancer, a great challenge is the fabrication of straightforward, non-toxic, multifunctional green nanomaterials. In this study, carbon quantum dots self-assembled with indocyanine green dye at bovine serum albumin for phototherapy and in situ bioimaging are produced by a flexible hydrothermal method. We find that the synthesized nanoparticles have high tumor photothermal therapeutic activity when exposed to 808 nm light, with a photothermal conversion efficiency up to 61 %. The phototoxicity study revealed the excellent phototherapy of the nanoparticles mainly arises from photothermal therapeutic effect other than photodynamic therapy effect. Simultaneously, it allows biological imaging in the visible and near-infrared ranges because of the significant absorption at 365 nm and 840 nm. The current work offers a simple, environmentally friendly, and reasonable method for developing photothermal drugs with a high photothermal conversion efficiency in the near-infrared region, as well as good biosafety for multifunctional nanomaterials for bioimaging tumor diagnosis and direct phototherapy.

Phthalocyanine-based probes in alleviating or evading tumour-hypoxia for enhanced photo- and/ sono-mediated therapeutic efficacies

This review discusses the possible methods for improving therapeutic efficacies of phthalocyanine (Pcs) -based therapeutic probes in photo- and sono-dynamic therapies under hypoxic conditions. Herein, the structural design strategies including varying the central metal, position substituents and the effects of adjuvant used in supplementing the therapeutics activities of Pcs or formation of NPs are discussed for cancer therapies in hypoxic conditions. Different mechanisms induced for cell death influenced by the compositions of the Pcs-probes are discussed. The focus mainly highlights the oxygen (O2) -dependent mechanisms including methods of supplementing tumour microenvironment O2-concentrations to promote PDT or SDT therapies. Alternatively, O2-independent mechanisms mainly used to evade hypoxia by stimulating anticancer processes that don't require O2 to initiate cell death, such as the Fenton reaction or thermal ablation effects.

MRI-guided photothermal/photodynamic immune activation combined with PD-1 inhibitor for the multimodal combination therapy of melanoma and metastases

Non-invasive image-guided precise photothermal/photodynamic therapy (PTT/PDT) has been proven to be an effective local treatment modality but incompetent against metastases. Hence, the combination of local PTT/PDT and systemic immunotherapy would be a promising strategy for tumor eradication. Herein, a magnetic resonance imaging (MRI)-visualized PTT/PDT agent (SIDP NMs) was constructed, and the efficacy of its multimodal combination with a programmed cell death 1 (PD-1) inhibitor in the treatment of melanoma and metastases was studied. Due to the hydrophobic encapsulation of indocyanine green within the micellar core, SIDP NMs exhibited excellent photothermal/photodynamic properties and stability under an 808 nm near-infrared laser. In vitro cell experiments showed that SIDP NMs had a good killing effect. After incubating with B16-F10 cells for 24 h and irradiating with an 808-nm laser for 10 min, cell viability decreased significantly. Magnetic resonance imaging experiments in melanoma-bearing mice have shown that the dynamic distribution of SIDP NMs in tumor tissue could be monitored by T2WI and T2-MAP non-invasively due to the presence of superparamagnetic iron oxide nanocrystal in SIDP NMs. When the 808 nm laser was irradiated at the maximum focusing time point shown by MRI, the temperature of the tumor area rapidly increased from 32°C to 60.7°C in 5 min. In mouse melanoma ablation and distant tumor immunotherapy studies, SIDP NMs provided excellent MRI-guided PTT/PDT results and, when combined with PD-1 inhibitor, have great potential to cure primary tumors and eradicate metastases.

Schottky Junction Nanozyme Based on Mn-Bridged Co-Phthalocyanines and Ti3C2Tx Nanosheets Boosts Integrative Type I and II Photosensitization for Multimodal Cancer Therapy

Cancer phototheranostics have the potential for significantly improving the therapeutic effectiveness, as it can accurately diagnose and treat cancer. However, the current phototheranostic platforms leave much to be desired and are often limited by tumor hypoxia. Herein, a Schottky junction nanozyme has been established between a manganese-bridged cobalt-phthalocyanines complex and Ti₃C₂T_x MXene nanosheets (CoPc-Mn/Ti₃C₂T_x), which can serve as an integrative type I and II photosensitizer for enhancing cancer therapeutic efficacy via a photoacoustic imaging-guided multimodal chemodynamic/photothermal/photodynamic therapy strategy under near-infrared (808 nm) light irradiation. The Schottky junction not only possessed a narrow-bandgap, enhanced electron-hole separation ability and exhibited a potent redox potential but also enabled improved H₂O₂ and O₂ supplying performances in vitro. Accordingly, the AS1411 aptamer-immobilized CoPc-Mn/Ti₃C₂T_x nanozyme illustrated high accuracy and excellent anticancer efficiency through a multimodal therapy strategy in in vitro and in vivo experiments. This work presents a valuable method for designing and constructing a multifunctional nanocatalytic medicine platform for synergistic cancer therapy of solid tumors.

Near-Infrared Phototheranostic Iron Pyrite Nanocrystals Simultaneously Induce Dual Cell Death Pathways via Enhanced Fenton Reactions in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is considered more aggressive with a poorer prognosis than other breast cancer subtypes. Through systemic bioinformatic analyses, we established the ferroptosis potential index (FPI) based on the expression profile of ferroptosis regulatory genes and found that TNBC has a higher FPI than non-TNBC in human BC cell lines and tumor tissues. To exploit this finding for potential patient stratification, we developed biologically amenable phototheranostic iron pyrite FeS2 nanocrystals (NCs) that efficiently harness near-infrared (NIR) light, as in photovoltaics, for multispectral optoacoustic tomography (MSOT) and photothermal ablation with a high photothermal conversion efficiency (PCE) of 63.1%. Upon NIR irradiation that thermodynamically enhances Fenton reactions, dual death pathways of apoptosis and ferroptosis are simultaneously triggered in TNBC cells, comprehensively limiting primary and metastatic TNBC by regulating p53, FoxO, and HIF-1 signaling pathways and attenuating a series of metabolic processes, including glutathione and amino acids. As a unitary phototheranostic agent with a safe toxicological profile, the nanocrystal represents an effective way to circumvent the lack of therapeutic targets and the propensity of multisite metastatic progression in TNBC in a streamlined workflow of cancer management with an integrated image-guided intervention.

Cancer therapeutics based on diverse energy sources

Light-based phototherapy has been developed for cancer treatment owing to its non-invasiveness and spatiotemporal control. Despite the unique merits of phototherapy, one critical disadvantage of light is its limited penetration depth, which restricts its application in cancer treatment. Although many researchers have developed various strategies to deliver light into deep-seated tumors with two-photon and near-infrared light irradiation, phototherapy encounters the peculiar limitations of light. In addition, high oxygen dependency is another limitation of photodynamic therapy to treat hypoxic tumors. To overcome the drawbacks of conventional treatments, various energy sources have been developed for cancer treatment. Generally, most energy sources, such as ultrasound, chemiluminescence, radiation, microwave, electricity, and magnetic field, are relatively free from the restraint of penetration depth. Combining other strategies or therapies with other energy-source-based therapies improves the strength and compensates for the weakness. This tutorial review focuses on recent advances in the diverse energy sources utilized in cancer treatment and their future perspectives.

Docetaxel-Loaded Novel Nano-Platform for Synergistic Therapy of Non-Small Cell Lung Cancer

Nowadays, non-small cell lung cancer (NSCLC) is threatening the health of all mankind. Although many progresses on treatment of lung cancer have been achieved in the past few decades, the current treatment methods are still traditional surgery, radiotherapy, and chemotherapy, which had poor selectivity and side effects. Lower-toxicity and more efficient treatments are in sore need. In this paper, a smart nanodelivery platform based on photothermal therapy, chemotherapy, and immunotherapy was constructed. The nanoparticles are composed of novel photothermal agents, Mn-modified phthalocyanine derivative (Mn^IIIPC), docetaxel (DTX), and an effective targeting molecule, hyaluronic acid. The nanoplatform could release Mn²⁺ from Mn^IIIPC@DTX@PLGA@Mn²⁺@HA(MDPMH) and probably activate tumor immunity through cGAS-STING and chemotherapy, respectively. Furthermore, DTX could be released in the process for removal of tumor cells. The “one-for-all” nanomaterial may shed some light on treating NSCLC in multiple methods.

Photophysical Properties of Linked Zinc Phthalocyanine to Acryloyl Chloride:N-vinylpyrrolidone Copolymer

This paper focuses on the linking of zinc phthalocyanine (ZnPc) to N-vinylpyrrolidone (N-VP): acryloyl chloride (ClAC) copolymer. The synthesis of binary N-VP:ClAC copolymer was performed by the radical polymerization method and then grafted to ZnPc by the Friedel Crafts acylation reaction. We have developed a water-soluble ZnPc:ClAC:N-VP photosensitizer with a narrow absorption band at 970 nm, fluorescence at λ_em = 825 nm and the decay fluorescence profile with 3-decay relatively longer times of 1.2 µs, 4.6 µs, and 37 µs. The concentration-dependent dark cytotoxicity investigated in normal fibroblasts (NHDF), malignant melanoma (MeWo), adenocarcinoma (HeLa), and hepatocellular carcinoma (HepG2) cell lines incubated to increased concentrations of ZnPc:ClAC:N-VP (up to 40 μM) for 24 h in the dark show low cytotoxicity. Maximum cell viability in HeLa and HepG2 tumor cell lines was observed.

A bacteria-triggered wearable colorimetric band-aid for real-time monitoring and treating of wound healing

Early diagnosis of bacterial infection and tracking of treatment effect are of great importance for developing a "sense-and-treat" integrated system. Herein, we developed a bacteria-triggered, portable, wearable and colorimetric film-based band-aid (FBA) for closed-loop monitoring and light-controlled therapy of wound infection. FBA with high photothermal conversion efficiency of 52.56% was prepared by wrapping Bi₂S₃ nanoflowers (BS NFs) loaded with rhodium nanoparticles (Rh NPs) and bromothymol blue (BTB) into LB agar film, integrating bacteria-triggered color change, photothermal/photodynamic therapy (PTT/PDT) synergistic bactericidal therapy and agar-based band aid in one intelligent system. Initially, FBA effectively simulates the pH sensing mechanism, and monitors the occurrence of bacterial infections within 5 min through color changes of Staphylococcus aureus (S. aureus) from blue to yellow and Escherichia coli (E. coli) from yellow to blue. Additionally, the short-term and controlled antibacterial strategy of "one light dual-mode responses" (photothermal and photodynamic responses) was implemented with the introduce of near-infrared (NIR). Ultimately, the effectiveness of FBA was fully validated in the monitoring and treating of S. aureus-infected mouse wounds. Notably, the designed FBA decisively abandoned off-target side effects maximizing the treatment effect and nakedly tracking therapeutic situation in real time, contributing an effective antibacterial alternative strategy for reducing the use of antibiotics. To the best of our knowledge, such integrated system is still unreported on film-fixed model. In view of the advantages of the low cost and convenience of the simple device, the integrated design is expected to provide a solution for the development of a closed-loop biomedical system combining diagnosis and treatment.

Recent Progress in Phthalocyanine-Polymeric Nanoparticle Delivery Systems for Cancer Photodynamic Therapy

This perspective article summarizes the last decade’s developments in the field of phthalocyanine (Pc)-polymeric nanoparticle (NP) delivery systems for cancer photodynamic therapy (PDT), including studies with at least in vitro data. Moreover, special attention will be paid to the various strategies for enhancing the behavior of Pc-polymeric NPs in PDT, underlining the great potential of this class of nanomaterials as advanced Pcs’ nanocarriers for cancer PDT. This review shows that there is still a lot of research to be done, opening the door to new and interesting nanodelivery systems.

Recent advances in nanoparticles mediated photothermal therapy induced tumor regression

Photothermal therapy (PTT) is a minimally invasive procedure for treating cancer. The two significant prerequisites of PTT are the photothermal therapeutic agent (PTA) and near-infrared radiation (NIR). The PTA absorbs NIR, causing hyperthermia in the malignant cells. This increased temperature at the tumor microenvironment finally results in tumor cell damage. Nanoparticles play a crucial role in PTT, aiding in the passive and active targeting of the PTA to the tumor microenvironment. Through enhanced permeation and retention effect and surface-engineering, specific targeting could be achieved. This novel delivery tool provides the advantages of changing the shape, size, and surface attributes of the carriers containing PTAs, which might facilitate tumor regression significantly. Further, inclusion of surface engineering of nanoparticles is facilitated through ligating ligands specific to overexpressed receptors on the cancer cell surface. Thus, transforming nanoparticles grants the ability to combine different treatment strategies with PTT to enhance cancer treatment. This review emphasizes properties of PTAs, conjugated biomolecules of PTAs, and the combinatorial techniques for a better therapeutic effect of PTT using the nanoparticle platform.

Nucleic Acid Delivery with Red-Blood-Cell-Based Carriers

Gene therapy has the potential to become a staple of 21st-century medicine. However, to overcome the limitations of existing gene-delivery therapies, that is, poor stability and inefficient and delivery and accumulation of nucleic acids (NAs), safe drug-delivery systems (DDSs) allowing the prolonged circulation and expression of the administered genes in vivo are needed. In this review article, the development of DDSs over the past 70 years is briefly described. Since synthetic DDSs can be recognized and eliminated as foreign substances by the immune system, new approaches must be found. Using the body's own cells as DDSs is a unique and exciting strategy and can be used in a completely new way to overcome the critical limitations of existing drug-delivery approaches. Among the different circulatory cells, red blood cells (RBCs) are the most abundant and thus can be isolated in sufficiently large quantities to decrease the complexity and cost of the treatment compared to other cell-based carriers. Therefore, in the second part, this article describes 70 years of research on the development of RBCs as DDSs, covering the most important RBC properties and loading methods. In the third part, it focuses on RBCs as the NA delivery system with advantages and drawbacks discussed to decide whether they are suitable for NA delivery in vivo.

Poly(2-ethyl-2-oxazoline-co-ethyleneimine)-block-poly(ε-caprolactone) based micelles: synthesis, characterization, peptide conjugation and cytotoxic activity

Here we present self-assembled polymeric micelles as potential delivery systems for therapeutic agents with highly tunable properties.

Dual-light triggered metabolizable nano-micelles for selective tumor-targeted photodynamic/hyperthermia therapy

Phototherapy, including photodynamic and photothermal therapies, is a non-invasive photo-triggered tumor treatment. Combination therapy and new synergistic therapeutic reagents may hold promise for improving these treatments. Herein, we report an amphiphilic iridium-based photosensitizer (C14-IP2000) loaded with a hydrophobic photo-thermal drug (ZnPc) to form nano-micelles (ZNPs) for dual-light triggered tumor phototherapy. The C14-IP2000 was contained within ZNPs consisting of an iridium complex core decorated with hydrophilic polyethylene glycol chains to extend the time in blood circulation, and two hydrophobic carbon chains to enhance the loading capacity and the hydrophobic interaction with the loaded reagent. The designed ZNPs showed effective blood circulation, passive tumor targeting ability, remarkable photodynamic conversion ability, and good photothermal conversion capability, and therefore may be used for combined tumor ablation. Our results demonstrated that the amphipathic bionic structure of ZNPs not only enables self-assembled reagent fabrication with prolonged circulation time and favorable metabolic characteristics for tumor combination therapy, but also provides a nanostructure strategy for the modification of functionalized reagents.

A non-aggregated zinc(II) phthalocyanine with hexadeca cations for antitumor and antibacterial photodynamic therapies

With a view to developing highly efficient photosensitizers for both antitumor and antimicrobial photodynamic therapies, herein, we reported a super cationic zinc(II) phthalocyanine (Pc4), which was prepared through the quaternization of the N, N-dimethyl-3-aminophenoxyl-hexadeca-substituted precursor Pc3. Meanwhile, two disubstituted analogues (Pc1 and Pc2) were also prepared as controls. The cationic Pc2 and Pc4 had higher photoactivities including fluorescence and singlet oxygen than the neutral counterparts Pc1 and Pc3, probably because of the inhibition of intramolecular charge transfer (ICT) effect of the amino groups. With the bulky steric effect and high hydrophilicity, Pc4 presented non-aggregated behavior in aqueous solutions. Therefore, it exhibited the highest in vitro photodynamic activity toward HepG2 cancer cells with an IC₅₀ value as low as 0.04 μM. Furthermore, Pc4 showed a highly efficient in vivo PDT effect on H22 tumor-bearing mice with 98.7% tumor growth inhibition. In addition, Pc4 also exhibited an excellent in vitro and in vivo photodynamic inactivation against S. aureus. The results indicate that the non-aggregated hexadeca-cationic Pc4 could serve as a promising photosensitizer for both antitumor and antimicrobial photodynamic therapies.

Multifunctional HNT@Fe3O4@PPy@DOX Nanoplatform for Effective Chemo-Photothermal Combination Therapy of Breast Cancer with MR Imaging

Multifunctional nanoparticles for imaging and treatment in cancer are getting more and more attention recently. Herein, halloysite nanotubes (HNTs), natural clay nanotubes, are designed as multifunctional nanoplatform for targeted delivering photothermal therapy agents and chemotherapeutic drugs. Fe₃O₄ was anchored on the outer surfaces of HNTs and then doxorubicin (DOX) was loaded on the nanotubes. Afterward, a layer of polypyrrole (PPy), as photothermal agent, was wrapped on the tubes. The nanoplatform of HNT@Fe₃O₄@PPy@DOX can be guided to tumor tissue by an external magnetic field, and then performs chemo-photothermal combined therapy by 808 nm laser irradiation. HNT@Fe₃O₄@PPy@DOX shows the ability of T₂-weighted magnetic resonance imaging, which could be considered as a promising application in magnetic targeting tumor therapy. In vitro and in vivo experiments demonstrate that HNTs nanoplatform has good biocompatibility and produces a strong antitumor effect trigged by near-infrared laser irradiation. The novel chemo-photothermal therapy nanoplatform based on HNTs may be developed as a multifunctional nanoparticle for imaging and therapy in breast cancer.

Near-infrared and metal-free tetra(butylamino)phthalocyanine nanoparticles for dual modal cancer phototherapy

Synergistic phototherapy combining photodynamic therapy (PDT) and photothermal therapy (PTT) based on near-infrared (NIR) dyes using a single light source offers the opportunity to treat diseases at deep locations. In this study, we reported human serum albumin (HSA)-involving tetra(butylamino)phthalocyanine (Pc)-based nanomaterials of HSA-α-Pc and HSA-β-Pc as highly efficient dual-phototherapy agents, namely 1(4),8(11),15(18),22(25)-tetra(butylamino)phthalocyanine (α-Pc) and 2(3),9(10),16(17),23(24)-tetra(butylamino)phthalocyanine (β-Pc). Both HSA-α-Pc and HSA-β-Pc showed excellent photothermal effects under a single NIR (808 nm) laser irradiation due to the S₁ fluorescence emission quenching of Pcs. Compared to HSA-β-Pc, HSA-α-Pc exhibited better singlet oxygen generation ability and its highly efficient PDT/PTT dual-phototherapy was also well evidenced via in vitro and vivo experiments under a single 808 nm laser irradiation. Overall, this approach would be viable for the fabrication of more new Pc-based metal-free nano agents for PDT/PTT synergistic phototherapy upon a single NIR light source.

Two new HSA-involved tetra(butylamino)phthalocyanine composite nanoparticles, as highly efficient dual-phototherapy agents upon a single NIR laser irradiation, were reported.

Novel phthalocyanine-based micelles/PNIPAM composite hydrogels: spatially/temporally controlled drug release triggered by NIR laser irradiation

Near-infrared (NIR) light-responsive hydrogels hold significant potential for biomedical application, especially in the remote-controlled release of anticancer drugs.

Single-molecular phosphorus phthalocyanine-based near-infrared-II nanoagent for photothermal antitumor therapy

As one of the noninvasive cancer treatments, photothermal therapy (PTT) has drawn intense attention recently. In this context, an important task is to explore novel and versatile nanoscale photothermal agents (PTAs), especially those with strong NIR-II light absorption, high photothermal conversion efficiency, good photostability and biocompatibility. Phthalocyanines (Pcs), as the second-generation photosensitizers, are a promising class of candidates for PTT due to their strong NIR absorption and high photothermal conversion efficiency. However, the poor water solubility severely limited their application as PTAs in tumor treatment. Herein, we report a molecular phosphorus phthalocyanine (P-Pc)-based nanoagent via incorporation of human serum albumin (HSA) under mild conditions. The obtained nanoscale P-Pc-HSA possesses excellent photothermal conversion efficiency (64.7%) upon 1064 nm light irradiation, furthermore, it can be a highly efficient NIR-II antitumor nanoagent via photothermal treatment (PTT), which is fully evidenced by the in vitro and in vivo experiments.

A molecular phosphorus phthalocyanine (P-Pc)-based nanoagent P-Pc-HSA, which can be a highly efficient NIR-II antitumor agent, is reported.

Nanoscale Covalent Organic Framework for Combinatorial Antitumor Photodynamic and Photothermal Therapy

Despite the excellent photodynamic and photothermal properties of organic molecular photosensitizers (PSs) and photothermal agents (PTAs), such as porphyrin and naphthalocyanine, their poor water solubility severely impedes their biological applications. Covalent organic frameworks (COFs), as an emerging class of organic crystalline porous materials, possess free active end groups (bonding defects) and large inner pores, which make them an ideal type of nanocarriers for loading hydrophobic organic molecular PSs and PTAs by both bonding defect functionalization (BDF) and guest encapsulation approaches to obtain multifunctional nanomedicines for PDT/PTT combination therapy. In this work, we report a nanoscale COF (NCOF) prepared via a facile synthetic approach under ambient conditions. Furthermore, a dual-modal PDT/PTT therapeutic nanoagent, VONc@COF-Por (3), is successfully fabricated by stepwise BDF and guest encapsulation processes. The covalently grafted porphyrinic PS (Por) and the noncovalently loaded naphthalocyanine PTA (VONc) are independently responsible for the PDT and PTT functionalities of the nanoagent. Upon visible (red LED) and NIR (808 nm laser) irradiation, VONc@COF-Por (3) displayed high ¹O₂ generation and photothermal conversion ability (55.9%), consequently providing an excellent combined PDT/PTT therapeutic effect on inhibiting MCF-7 tumor cell proliferation and metastasis, which was well evidenced by in vitro and in vivo experiments. We believe that the results obtained herein can significantly promote the development of NCOF-based multifunctional nanomedicines for biomedical applications.