Self-Assembled Naphthalimide Conjugated Porphyrin Nanomaterials with D–A Structure for PDT/PTT Synergistic Therapy

Glycosylated nanoplatforms: From glycosylation strategies to implications and opportunities for cancer theranostics

Glycosylated nanoplatforms have emerged as promising tools in the field of cancer theranostics, integrating both therapeutic and diagnostic functionalities. These nanoscale platforms are composed of different materials such as lipids, polymers, carbons, and metals that can be modified with glycosyl moieties to enhance their targeting capabilities towards cancer cells. This review provides an overview of different modification strategies employed to introduce glycosylation onto nanoplatforms, including chemical conjugation, enzymatic methods, and bio-orthogonal reactions. Furthermore, the potential applications of glycosylated nanoplatforms in cancer theranostics are discussed, focusing on their roles in drug delivery, imaging, and combination therapy. The ability of these nanoplatforms to selectively target cancer cells through specific interactions with overexpressed glycan receptors is highlighted, emphasizing their potential for enhancing efficacy and reducing the side effects compared to conventional therapies. In addition, the incorporation of diagnostic components onto the glycosylated nanoplatforms provided the capability of simultaneous imaging and therapy and facilitated the real-time monitoring of treatment response. Finally, challenges and future perspectives in the development and translation of glycosylated nanoplatforms for clinical applications are addressed, including scalability, biocompatibility, and regulatory considerations. Overall, this review underscores the significant progress made in the field of glycosylated nanoplatforms and their potential to revolutionize cancer theranostics.

A Novel Multi-Effect Photosensitizer for Tumor Destruction via Multimodal Imaging Guided Synergistic Cancer Phototherapy

Background

How to ingeniously design multi-effect photosensitizers (PSs), including multimodal imaging and multi-channel therapy, is of great significance for highly spatiotemporal controllable precise phototherapy of malignant tumors.

Methods

Herein, a novel multifunctional zinc(II) phthalocyanine-based planar micromolecule amphiphile (ZnPc 1) was successfully designed and synthesized, in which N atom with photoinduced electron transfer effect was introduced to enhance the near-infrared absorbance and nonradiative heat generation. After simple self-assembling into nanoparticles (NPs), ZnPc 1 NPs would exhibit enhanced multimodal imaging properties including fluorescence (FL) imaging (FLI) /photoacoustic (PA) imaging (PAI) /infrared (IR) thermal imaging, which was further used to guide the combined photodynamic therapy (PDT) and photothermal therapy (PTT).

Results

It was that under the self-guidance of the multimodal imaging, ZnPc 1 NPs could precisely pinpoint the tumor from the vertical and horizontal boundaries achieving highly efficient and accurate treatment of cancer.

Conclusion

Accordingly, the integration of FL/PA/IR multimodal imaging and PDT/PTT synergistic therapy pathway into one ZnPc 1 could provide a blueprint for the next generation of phototherapy, which offered a new paradigm for the integration of diagnosis and treatment in tumor and a promising prospect for precise cancer therapy.

Self-Assembled Matrine-PROTAC Encapsulating Zinc(II) Phthalocyanine with GSH-Depletion-Enhanced ROS Generation for Cancer Therapy

The integration of a multidimensional treatment dominated by active ingredients of traditional Chinese medicine (TCM), including enhanced chemotherapy and synergistically amplification of oxidative damage, into a nanoplatform would be of great significance for furthering accurate and effective cancer treatment with the active ingredients of TCM. Herein, in this study, we designed and synthesized four matrine-proteolysis-targeting chimeras (PROTACs) (depending on different lengths of the chains named LST-1, LST-2, LST-3, and LST-4) based on PROTAC technology to overcome the limitations of matrine. LST-4, with better anti-tumor activity than matrine, still degrades p-Erk and p-Akt proteins. Moreover, LST-4 NPs formed via LST-4 self-assembly with stronger anti-tumor activity and glutathione (GSH) depletion ability could be enriched in lysosomes through their outstanding enhanced permeability and retention (EPR) effect. Then, we synthesized LST-4@ZnPc NPs with a low-pH-triggered drug release property that could release zinc(II) phthalocyanine (ZnPc) in tumor sites. LST-4@ZnPc NPs combine the application of chemotherapy and phototherapy, including both enhanced chemotherapy from LST-4 NPs and the synergistic amplification of oxidative damage, through increasing the reactive oxygen species (ROS) by photodynamic therapy (PDT), causing an GSH decrease via LST-4 mediation to effectively kill tumor cells. Therefore, multifunctional LST-4@ZnPc NPs are a promising method for killing cancer cells, which also provides a new paradigm for using natural products to kill tumors.

Red fluorescent BODIPY-based nanoparticles for targeted cancer imaging-guided photodynamic therapy

Imaging-guided diagnosis and treatment of cancer hold potential to significantly improve therapeutic accuracies and efficacies. Central to this theragnostic approach has been the use of multicomponent-based multimodal nanoparticles (NPs). Apart from this conventional approach, here we propose a design strategy for the simple and straightforward formulation of NPs based on boron dipyrromethene (BODIPY) derivatives, LaB-X (X = H, Et, and Br). Specifically, the conjugation of lactose to the inherently hydrophobic BODIPY promoted the formation of LaB-X NPs in water. Furthermore, the BODIPY backbone was subjected to distyrylation, dibromination, and diethylation to tailor the optical window and the balance between fluorescence and singlet oxygen generation capabilities. We demonstrate that while the photoinduced anticancer activities of LaB-H and LaB-Et NPs were trivial, LaB-Br NPs effectively induced the apoptotic death of hepatocellular carcinoma cells under red light irradiation while allowing fluorescence cell imaging in the phototherapeutic window. This dual fluorescence photosensitizing activity of LaB-Br NPs could be switched off and on, so that both fluorescence and singlet oxygen generation were paused during NP formation in an aqueous solution, while both processes resumed after cellular uptake, likely due to NP disassembly.

Novel naphthalimide bridged zinc porphyrin/BODIPY nanomaterials with D-A structure for photodynamic therapy

As a non-invasive cancer therapy method, photodynamic therapy (PDT) shows tremendous promise in clinical cancer treatment. Light-activated singlet oxygen production of photosensitizers (PSs) is the prerequisite for cancer PDT, and the use of organic photosensitizers is always limited by visible light-based activation, hydrophilicity, biocompatibility, selectivity and quantum yield of singlet oxygen. Currently, both zinc porphyrin- and BODIPY-based structures have been widely used in the development of PDT PSs. Here, we developed a novel naphthalimide bridged zinc porphyrin/BODIPY molecule (Por-BDP-1) with two poly(ethylene glycol) (PEG) chains, in which D-A structure was constructed between the naphthalimide group and porphyrin group. After self-assembly into nanoparticles, Por-BDP-1 NPs (Diameter: 122.4 nm) could quench fluorescence in 600–700 nm, bind with calf thymus-DNA, and produce singlet oxygen during light-irradiation (laser: 680 nm, 1.0 W/cm[Formula: see text]. In addition, Por-BDP-1 NPs effectively killed HeLa cells with a IC[Formula: see text] value = 44.8 μg/mL and showed a lower dark toxicity under the same conditions. All our results demonstrated that our naphthalimide bridged zinc porphyrin/BODIPY nano-photosensitizer is a promising nanoagent for PDT in the clinic.

Biomedical Application of Porphyrin-Based Amphiphiles and Their Self-Assembled Nanomaterials

Porphyrins have been vastly explored and applied in many cutting-edge fields with plenty of encouraging achievements because of their excellent properties. As important derivatives of porphyrins, porphyrin-based amphiphiles (PBAs) not only maintain the advanced properties of porphyrins (catalysis, imaging, and energy transfer) but also possess self-assembly and encapsulation capability in aqueous solution. Accordingly, PBAs and their self-assembles have had important roles in diagnosing and treating tumors and inflammation lesions in vivo, but not limited to these. In this article, we introduce the research progress of PBAs, including their constitution, structure design strategies, and performances in tumor and inflammation lesion diagnosis and treatments. On that basis, the defects of synthesized PBAs during their application and the possible effective strategies to overcome the limitations are also proposed. Finally, perspectives on PBAs exploration are updated based on our knowledge. We hope this review will bring researchers from various domains insights about PBAs.

Molecular Engineering Design of Enhanced Donor-Acceptor Therapeutic Reagent for Efficient Image-Guided Photodynamic Therapy

The greatest barrier to the further development and clinical application of tumor image-guided photodynamic therapy (PDT), is the inconsistency between the fluorescence intensity and singlet oxygen generation yield of the photosensitizer under light excitation. Herein, a novel donor-acceptor (D-A) system is designed from the point of molecular selection by wrapping a classical porphyrin molecule (5,10,15,20-tetraphenylphorphyrin, H2 TPP) as an acceptor into conjugated polymer (Poly[N,N'-bis(4-butylpheny)-N,N'-bis(phenyl)benzidine], ADS254BE) as a donor through fluorescence resonance energy transfer (FRET) mechanism, which exhibits bright red emission centered at 650 nm (quantum yield, 0.12), relatively large Stoke shift of 276 nm, enhanced singlet oxygen generation rate of 0.73, and excellent photostability. The investigations on distribution and killing effect of nanomaterials in cancer cells reveal that ADS254BE/H2 TPP NPs can accumulate in the cytoplasm for imaging while simultaneously producing a large amount of singlet oxygen to remarkably kill cancer cells, which can be used for real-time image-guided PDT. In the xenograft tumor model, real-time imaging and long-term tracing in tumor tissue with ADS254BE/H2 TPP NPs disclose that the growth of lung cancer in mice can be effectively inhibited during in situ imaging. From the standpoint of molecular engineering design, this work provides a feasible strategy for novel D-A systems to improve the development of image-guided PDT.

Near-Infrared BODIPY Photosensitizer for Modulating Mitochondrial Fusion Proteins and Inhibiting Choroidal Neovascularization

Photosensitizers have emerged as cytotoxic reactive oxygen species (ROS) activators in photodynamic therapy (PDT), which induced cell apoptosis. As the major contributors to ROS and oxidative stress, mitochondria play an important role in cell apoptosis. Although there are many reports about near-infrared 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) as photosensitizers (PSs) for PDT, this kind of PS has rarely been used for treating mitochondrial function and choroidal neovascularization application at the same time. Herein, a novel near-infrared PS (BDP2) characterized by good water solubility, long wavelength excitation, and high ROS quantum yield has been made. Under near-infrared light irradiation, BDP2 would generate ROS with high yield, induce a mitochondrial morphology change, and trigger cell apoptosis by changing the fusion protein level. Deep investigation revealed that BDP2 can cause oxidative stress, break the balance between fusion and fission of mitochondrial dynamics protein through decreasing fusion protein MFN2 and OPA1 expression, and finally cause cell apoptosis. Due to these characteristics, the BDP2 PS was used to treat choroidal neovascularization in animal models and can inhibit neovascularization.

Near-infrared photodynamic and photothermal co-therapy based on organic small molecular dyes

Near-infrared (NIR) organic small molecule dyes (OSMDs) are effective photothermal agents for photothermal therapy (PTT) due to their advantages of low cost and toxicity, good biodegradation, and strong NIR absorption over a wide wavelength range. Nevertheless, OSMDs have limited applicability in PTT due to their low photothermal conversion efficiency and inadequate destruction of tumor regions that are nonirradiated by NIR light. However, they can also act as photosensitizers (PSs) to produce reactive oxygen species (ROS), which can be further eradicated by using ROS-related therapies to address the above limitations of PTT. In this review, the synergistic mechanism, composition, and properties of photodynamic therapy (PDT)-PTT nanoplatforms were comprehensively discussed. In addition, some specific strategies for further improving the combined PTT and PDT based on OSMDs for cancer to completely eradicate cancer cells were outlined. These strategies include performing image-guided co-therapy, enhancing tumor infiltration, increasing H2O2 or O2 in the tumor microenvironment, and loading anticancer drugs onto nanoplatforms to enable combined therapy with phototherapy and chemotherapy. Meanwhile, the intriguing prospects and challenges of this treatment modality were also summarized with a focus on the future trends of its clinical application.

Enhanced Photodynamic Therapy by Improved Light Energy Capture Efficiency of Porphyrin Photosensitizers

OPINION STATEMENT

Photodynamic therapy (PDT) has garnered increasing attention in cancer treatment because of its advantages such as minimal invasiveness and selective destruction. With the development of PDT, impressive progress has been made in the preparation of photosensitizers, particularly porphyrin photosensitizers. However, the limited tissue penetration of the activating light wavelengths and relatively low light energy capture efficiency of porphyrin photosensitizers are two major disadvantages in conventional photosensitizers. Therefore, tissue penetration needs to be enhanced and the light energy capture efficiency of porphyrin photosensitizers improved through structural modifications. The indirect excitation of porphyrin photosensitizers using fluorescent donors (fluorescence resonance energy transfer) has been successfully used to address these issues. In this review, the enhancement of the light energy capture efficiency of porphyrins is discussed.

Iron-Doped Metal-Zinc-Centered Organic Framework Mesoporous Carbon Derivatives for Single-Wavelength NIR-Activated Photothermal/Photodynamic Synergistic Therapy

Recently, single-wavelength synergetic photothermal/photodynamic (PTT/PDT) therapy is beginning to make its mark in cancer treatment, and the key to it is a photosensitizer. In this work, an iron-doped metal-zinc-centered organic framework mesoporous carbon derivative (denoted as Fe_x-Zn-NC_T) with a similar porphyrin property was successfully synthesized by a mild, simple, and green aqueous reaction. The effects of different Fe contents and pyrolysis temperatures on the morphology, structure, and PTT/PDT of Fe_x-Zn-NC_T were investigated. Most importantly, we found that Fe₅₀-Zn-NC₉₀₀ exhibited excellent PTT/PDT performance under single-wavelength near-infrared (808 nm) light irradiation in a hydrophilic environment. The photothermal conversion efficiency (η) was counted as ∼81.3%, and the singlet oxygen (¹O₂) quantum yield (Φ) was compared with indocyanine green (ICG) as ∼0.0041. Furthermore, Fe₅₀-Zn-NC₉₀₀ is provided with a clear ability for generating ¹O₂ in living tumor cells and inducted massive necrosis/apoptosis of tumor cells with single-wavelength near-infrared laser irradiation. All of these are clear to consider that Fe₅₀-Zn-NC₉₀₀ displays great potential as an excellent photosensitizer for single-wavelength dual-mode PTT/PDT therapy.

Unimolecular micelles from star-shaped block polymers by photocontrolled BIT-RDRP for PTT/PDT synergistic therapy

Unimolecular micelles (UIMs) exhibit promising potential in the precise diagnosis and accurate treatment of tumor tissues, a pressing problem in the field of medical treatment, because of their perfect stability in the complex and variable microenvironment. In this study, porphyrin-based four-armed star-shaped block polymers with narrow molar mass dispersity (Đ = 1.34) were facilely prepared by photocontrolled bromine-iodine transformation reversible-deactivation radical polymerization (BIT-RDRP). A photothermal conversion dye, ketocyanine, was covalently linked onto the PEG and then introduced into the polymers through a "grafting onto" strategy to obtain polymeric nanomaterial, THPP-4PMMA-b-4P(PEGMA-co-APMA)@NIR-800, with dual PTT/PDT function. The resulting polymers could form monodispersed UIMs in the water below critical aggregation concentration, meanwhile maintaining the capacities of singlet oxygen release and photothermal conversion. Importantly, the UIMs displayed excellent biocompatibility while exerting superior PTT and/or PDT therapeutic effects under the irradiation of specific wavelengths of light, according to in vitro cellular experiments, which is expected to become a new hot spot for cancer therapy and anti-tumor research. Overall, stable and powerful UIMs with dual PTT/PDT function is provided, which are expected to be competitive candidates in cancer therapy.

Activatable self-assembled organic nanotheranostics: Aspartyl aminopeptidase triggered NIR fluorescence imaging-guided photothermal/photodynamic synergistic therapy

Phototherapy has developed as a powerful method for remedial modalities. The conventional photosensitizers are "always on" state and lack tumor targeting, which contributed to poor therapeutic effect and high toxicity. Therefore, we developed an aspartyl aminopeptidase (DNPEP) activated self-assembled organic nanoparticles (NRh-Asp NPs) with sensitive external irradiation-induced photothermal therapy and photodynamic therapy (PTT/PDT). NRh-Asp NPs can be activated to NRh-NH₂ NPs by DNPEP, demonstrating strong near-infrared (NIR) fluorescence, and efficiently generating heat and singlet oxygen under the near-infrared laser. NRh-Asp NPs was successfully used for visualizing DNPEP in vitro and in vivo in NIR region, and demonstrated good synergistic anti-cancer efficacy of PDT and PTT. These results suggest that DNPEP-mediated NRh-Asp NPs are promising candidates for image-guided phototherapeutic of tumor.

Advanced Research in Cellular Pharmacokinetics and its Cutting-edge Technologies

Pharmacokinetics (PK), as a significant part of pharmacology, runs through the overall process of the preclinical and clinical research on drugs and plays a significant role in determining the material basis of efficacy and mechanism research. However, due to the limitations of classical PK, cellular PK was put forward and developed rapidly. Many novel and original technologies have been innovatively applied to cellular PK research, thereby providing powerful technical support. As a novel field of PK research, cellular PK expands the research object and enriches the theoretical framework of PK. It provides a new perspective for elucidating the mechanism of drug action and the dynamic process of drug in the body. Furthermore, it provides a scientific basis and guiding significance for the development of new drugs and clinical rational drug use. Cellular PK can explain the dynamic process of certain drugs (e.g., antineoplastic drugs and antibiotics) and the disposition kinetics characteristics in some specific tissues (e.g., brain and tumor) in a clearer and more accurate manner. It is a beneficial supplement and the perfection of traditional PK. In the future, traditional and cellular PKs will complement each other well and improve into an all-around research system in drug developments. Briefly, this paper reviews the conceptual development of cellular PK and key associated technologies, explores its main functions and applications, and looks forward to the important pioneering significance and promising value for the development of PK.

Thermosensitive Liposomal Nanoplatform Based on Metal-Free Phthalocyanine with Copper(II)-Regulated Photoactivities

This work reports the development of a multifunctional thermosensitive liposomal nanoplatform (PcS4@Lip-FA) based on a metal-free phthalocyanine modified with tetra-sulfonates (PcPS4), which exhibited photodynamic and photothermal activities simultaneously. Upon irradiation with a near infrared laser, thermosensitive PcS4@Lip-FA could release PcS4 as a result of the local hyperthermia of PcS4. Interestingly, PcS4 could easily chelate with Cu2+, leading to the enhancement of photothermal activity and decrease of photodynamic activity. In addition, in vivo fluorescence imaging revealed that PcS4@Lip-FA could selectively accumulate in tumor tissue of H22 tumor-bearing mice after tail vein injection, and exhibited a significant anticancer phototherapeutic effect, with a tumor inhibition rate of 83.5 %. Therefore, PcPS4@Lip-FA has realized fluorescence imaging-guided combined cancer treatment, providing a promising multifunctional nanoplatform for cancer diagnostics and therapy.

Metal-organic frameworks for hepatocellular carcinoma therapy and mechanism

In recent years, metal organic frameworks (MOFs) have attracted increasing attention in cancer therapy, because they can enhance the anticancer efficacy of photodynamic therapy (PDT), photothermal therapy (PTT), photoacoustic imaging, and drug delivery. Owing to stable chemical adjustability, MOFs can be used as carriers to provide excellent loading sites and protection for small-molecule drugs. In addition, MOFs can be used to combine with a variety of therapeutic drugs, including chemotherapeutics drugs, photosensitizers, and radiosensitizers, to efficiently deliver drugs to tumor tissue and achieve desired treatment. There is hardly any review regarding the application of MOFs in hepatocellular carcinoma. In this review, the design, structure, and potential applications of MOFs as nanoparticulate systems in the treatment of hepatocellular carcinoma are presented.

Systematic Review Registration: website, identifier registration number

Porphyrin-Based Nanoparticles: A Promising Phototherapy Platform

Phototherapy, including photodynamic therapy and photothermal therapy, is an emerging form of non-invasive treatment. The combination of imaging technology and phototherapy is becoming an attractive development in the treatment of cancer, as it allows for highly effective therapeutic results through image-guided phototherapy. Porphyrins have attracted significant interest in the treatment and diagnosis of cancer due to their excellent phototherapeutic effects in phototherapy and their remarkable imaging capabilities in fluorescence imaging, magnetic resonance imaging and photoacoustic imaging. However, porphyrins suffer from poor water solubility, low near-infrared absorption and insufficient tumor accumulation. The development of nanotechnology provides an effective way to improve the bioavailability, phototherapeutic effect and imaging capability of porphyrins. This review highlights the research results of porphyrin-based small molecule nanoparticles in phototherapy and image-guided phototherapy in the last decade and discusses the challenges and directions for the development of porphyrin-based small molecule nanoparticles in phototherapy.

Naphthofluorescein-based organic nanoparticles with superior stability for near-infrared photothermal therapy

Photothermal agents (PTAs) based on organic small molecules with near-infrared (NIR) absorption (700-900 nm) have attracted increasing attention in cancer photothermal therapy (PTT). However, NIR organic PTAs often suffer from poor stability. Fluorescein and its derivatives have been widely used in biological imaging and sensing due to their minimal cytotoxicity. But fluorescein and its derivatives have not been used in PTT because most of them don't have NIR absorption. In this work, two NIR naphthofluorescein derivatives, namely NFOM-1 and NFOM-2, were synthesized. In contrast to NFOM-1, NFOM-2 possesses an intramolecular hydrogen bonding network, which extends the absorption to the NIR region and significantly improves the photostability. NFOM-2 was encapsulated into an amphiphilic polymer (DSPE-mPEG2000) to obtain NFOMNPs as PTAs. Compared to the organic molecule NFOM-2, the absorption of NFOMNPs is broadened and further red-shifted to fit an 808 nm light source. Moreover, NFOMNPs exhibit good photothermal conversion efficiency (PCE, 40.4%, 808 nm, 1.0 W cm^-2), remarkable photostability and physiological stability, and significant PTT efficacy in vitro and in vivo was achieved. In other words, this study provides an intramolecular hydrogen bond network strategy and a fluorescein-based molecular platform to construct ultra-stable PTAs for efficient NIR PTT.

Long-circulation zwitterionic dendrimer nanodrugs for phototherapy of tumors

The development of stealth and effective antitumor nanodrugs has been drawing great attention. Herein, generation five poly(amide amine) dendrimer (G5 PAMAM) was modified by zwitterionic material carboxybetaine methacrylamide (CBMAA) on its surface to prepare zwitterionic dendrimer (G5-CBMAA_n). The results showed that G5-CBMAA₃₀ had the longest blood circulation time due to its thickest zwitterionic layer, and its residual rate after injection into mice at 2 and 12 h was as high as 47.22 % and 14.37 %, respectively. Nanodrug G5-CBMAA₃₀-ICG was prepared by containing indocyanine green (ICG) in the cavity of G5-CBMAA₃₀. G5-CBMAA₃₀-ICG had better tumor targeting ability and antitumor effect than free ICG in mice after laser irradiation, and the tumor inhibition rate was 96.6 % after 14 days' treatment. The prepared G5-CBMAA₃₀-ICG has great potential applications in the field of antitumor by phototherapy.

Nanoplatform Self-Assembly from Small Molecules of Porphyrin Derivatives for NIR-II Fluorescence Imaging Guided Photothermal-Immunotherapy

Combinatorial photothermal and immunotherapy have demonstrated great potential to remove primary tumors, suppress metastases, and prevent tumor recurrence. However, this strategy still confronts patients with many limitations, such as complex components, sophisticated construction, and inadequate therapeutic efficacy. In this work, small molecules of porphyrin derivatives (PPor) which can self-assemble into monodispersed nanoparticles without supplement of any other ingredients or surfactants are developed. The formed PPor nanoparticles (PPor NPs) exhibit highly photothermal conversion efficiency of 70% and NIR-II luminous abilities originate from the strong intramolecular charge transfer (ICT) effect of D-A structure under 808 nm laser irradiation, thus achieving NIR-II fluorescence imaging guided photothermal therapy (PTT) against primary tumors with a high cure rate. More importantly, tumor-associated antigens (TAAs), together with damage-associated molecular patterns (DAMPs) released from PTT-treated cancer cells, are proved to elicit immune responses to some degree. After combination with programmed cell death-1 (PD-1) antibodies, a robust systematic antitumor immunity is generated to restrain both primary and abscopal tumors growth, prolong survival, and prevent pulmonary metastasis on an aggressive 4T1 murine breast tumor model. Thus, this study provides a promising therapeutic paradigm with porphyrin derivatives nano-assembly as phototheranostic agents for the treatment of aggressive tumors with high efficiency.

Two cationic meso-thiophenium porphyrins and their zinc-complexes as anti-HIV-1 and antibacterial agents under non-photodynamic therapy (PDT) conditions

The anti-HIV-1 and antimicrobial activities of novel cationic meso-thiophenium porphyrins and their zinc-complex are reported under in vitro non-photodynamic (PDT) conditions. While all the cationic porphyrins led to the inhibition of de novo virus infection, the Zn(II)-complexes of T₂(OH)₂M (A₂B₂-type) and T(OH)₃M (AB₃-type) displayed potent inhibition of HIV-1 entry with T₂(OH)₂MZn displaying maximal anti-HIV activity. The Zinc complex of both the thiophenium porphyrins T₂(OH)₂M and T(OH)₃M also depicted antibacterial activities against Escherichia coli (ATCC 25922) and more prominently against Staphylococcus aureus (ATCC 25923). Again, the antibacterial activity was more potent for T₂(OH)₂MZn. Our study highlighted that the presence of two thiophenium groups at the meso-positions of the A₂B₂-type porphyrins along with zinc strongly enhanced anti-HIV and antimicrobial properties of these novel thiophenium porphyrins under non-PDT conditions.

Water-soluble porphyrin photosensitizers containing electron-withdrawing and electron-donating groups for photodynamic therapy

Photodynamic therapy is used to treat a variety of cancers. In this paper, water-soluble porphyrin photosensitizers (H2P1[Formula: see text]H2P3) for photodynamic therapy were synthesized, containing three groups -CH3, -CN, and -CF3. Density functional theory is used to optimize the structure of H2P1-H2P3 and calculate the [Formula: see text]E value. The smaller the value of [Formula: see text]E, the more favorable the electron transfer and thus the higher activity of the porphyrin photosensitizers. Due to the electron-withdrawing groups of -CN and -CF3, H2P2 and H2P3 have lower [Formula: see text]E values, higher reactive oxygen species yields compared with H2P1. The H2P2 porphyrin photosensitizers showed positive photodynamic therapeutic activity against hepatocellular carcinoma cells (HepG2) and good compatibility with human umbilical vein endothelial cells (HUVECs) by cellular anticancer activity assay. The anti-cancer mechanism of PSs was explained by living and dead cell staining experiment and intracellular reactive oxygen species experiment. PSs produced reactive oxygen species (ROS) in cancer cells under light irradiation, which induced cancer cell apoptosis.

Photodynamic Therapy and Antibacterial Activities of a Novel Synthesized Quaternary Zn-Cu-In-S/ZnS QDs- mTHPP Porphyrin Conjugate

Background

Photodynamic therapy (PDT) is a non-invasive treatment modality that destroys abnormally growing cells or microorganisms. Porphyrins are used as photosensitizers in PDT; however, their clinical application has been limited by their poor water solubility, resulting in aggregation and low quantum yields of reactive oxygen species (ROS).

Methods

To overcome these limitations and improve PDT efficacy, we herein report the conjugation of ZnCuInS/ZnS (ZCIS/ZnS) quantum dots (QDs) to 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin (mTHPP). The optimal conditions for QDs porphyrin conjugation formation were systematically evaluated.

Discussion

This study further assessed the PDT efficacy and antibacterial potency of the synthesized ZCIS/ZnS-mTHPP conjugates. The PDT efficacy of the QDs, mTHPP, and conjugate was evaluated against the murine metastatic melanoma (B16 F10 Nex2) cell line. This was performed with and without LED irradiation.

Results

The conjugate exhibited the highest reduction in cell viability following LED irradiation (72%) compared to the bare QDs (19%) and mTHPP (1%). Antimicrobial studies conducted on E. coli showed that the conjugation exhibits a higher antibacterial effect than the bare QDs, even without light.

Conclusion

The results suggest that conjugate is a promising class of materials for anti-cancer and antimicrobial PDT.

Self-assembled porphyrin polymer nanoparticles with NIR-II emission and highly efficient photothermal performance in cancer therapy

The development of new organic nanoagents with extremely high photothermal conversion efficiency and good biocompatibility has gained considerable attention in the area of photothermal cancer therapy. In this work, we designed and synthesized a new porphyrin polymer (P-PPor) with donor-acceptor (D-A) structure. P-PPor displayed intense absorbance in the near-infrared (NIR) region with the maximum peak around at 850 ​nm. Under excitation of 808 ​nm, P-PPor demonstrated the significant fluorescence in the NIR-II region (λ max ​= ​1015 ​nm), with the fluorescence quantum yield of 2.19%. Due to the presence of hydrophilic PEG chains and hydrophobic alkyl chains in the conjugated skeleton, the amphiphilic P-PPor could self-assemble into the nanoparticles (P-PPor NPs) with good dispersibility in water and enhanced absorption in the NIR region. Moreover, P-PPor NPs exhibited quenched fluorescence because of the aggregation-caused quenching (ACQ) effect, resulting in the distinct photothermal effect. The photothermal conversion efficiency (PCE) of P-PPor NPs was measured as 66% under 808 ​nm laser irradiation, higher than most of PTT agents. The remarkable photothermal effect of P-PPor NPs was further demonstrated in vitro and in vivo using 4T1 tumor mode. Meanwhile, the NIR-II fluorescence imaging in vivo indicated the high distribution of P-PPor NPs in tumor site. These results suggested that P-PPor NPs could effectively damage the cancer cells in mice under 808 ​nm laser irradiation, and did not cause any obvious side effects after phototherapy. Thus, P-PPor NPs could be used as a potential agent in photothermal cancer therapy with high effectiveness and safety.

Recent Strategies to Develop Innovative Photosensitizers for Enhanced Photodynamic Therapy

This review presents a robust strategy to design photosensitizers (PSs) for various species. Photodynamic therapy (PDT) is a photochemical-based treatment approach that involves the use of light combined with a light-activated chemical, referred to as a PS. Attractively, PDT is one of the alternatives to conventional cancer treatment due to its noninvasive nature, high cure rates, and low side effects. PSs play an important factor in photoinduced reactive oxygen species (ROS) generation. Although the concept of photosensitizer-based photodynamic therapy has been widely adopted for clinical trials and bioimaging, until now, to our surprise, there has been no relevant review article on rational designs of organic PSs for PDT. Furthermore, most of published review articles in PDT focused on nanomaterials and nanotechnology based on traditional PSs. Therefore, this review aimed at reporting recent strategies to develop innovative organic photosensitizers for enhanced photodynamic therapy, with each example described in detail instead of providing only a general overview, as is typically done in previous reviews of PDT, to provide intuitive, vivid, and specific insights to the readers.

Nanoparticles for Triple Drug Release for Combined Chemo- and Photodynamic Therapy

A pH-responsive drug delivery system (DDS) based on mesoporous silica nanoparticles (MSNs) has been prepared for the delivery of three anticancer drugs with different modes of action. The novelty of this system is its ability to combine synergistic chemotherapy and photodynamic therapy. A photoactive conjugate of a phthalocyanine (Pc) and a topoisomerase I inhibitor (topo-I), namely camptothecin (CPT), linked by a poly(ethylene glycol) (PEG) chain has been synthesized and then loaded into the mesopores of MSNs. Doxorubicin (DOX), which is a topoisomerase II inhibitor (topo-II), has also been covalently anchored to the outer surface of the MSNs through a dihydrazide PEG linker. In the acidic environment of tumor cells, selective release of the three drugs takes place. In vitro studies have demonstrated the endocytosis of the system into HeLa and HepG2 cells, and the subsequent release of the three drugs into the cytoplasm and nucleus. Furthermore, the cytotoxic effect of DOX, CPT and Pc has been assessed in vitro before and upon light irradiation.

Triphenylamine-perylene diimide conjugate-based organic nanoparticles for photoacoustic imaging and cancer phototherapy

Phototherapy has gained great attention in the past decade owing to the advantages of high selectivity and low toxicity. However, it's still a challenge to develop a single photosensitizer that can achieve both photothermal and photodynamic effects. Herein, we design and synthesize a new organic compound (PIT) with a typical D-A-D structure through the covalent conjugation of perylene diimides (PDI) and triphenylamine (TPA). The amphiphilic PIT could be transformed to the nanoparticles (PIT NPs) through nanoprecipitation method. PIT NPs exhibit good water dispersibility with particle size around 70 nm. Because of the efficient NIR absorption, PIT NPs display high photothermal conversion efficiency (PCE) (η = 46.1 %) and strong photoacoustic signal under irradiation of 635 nm laser. Moreover, under the same laser irradiation, significant reactive oxygen species can be induced by PIT NPs both in aqueous solution and cancer cells. The MTT assay demonstrate the good biocompatibility and outstanding photocytotoxicity of PIT NPs. Thus, the as-prepared PIT NPs could be used as excellent candidates for photoacoustic imaging and photodynamic/photothermal therapy.

Assembled small organic molecules for photodynamic therapy and photothermal therapy

As a worldwide major public health problem, cancer is one of the leading causes of death. Effective treatment of cancer is an important challenge. Therefore, photodynamic therapy (PDT) and photothermal therapy (PTT) have been widely applied as anti-tumour strategies due to their high-performance and limited side effects. Inspired by natural supramolecular architectures, such as cytochromes and photosystems, the hierarchical supramolecular assembly of small organic molecules has been developed for their use as photosensitizers or photothermal agents for PDT and PTT, respectively. In this manuscript, we will summarize the recent progress of PDT and PTT based on the assembly of small organic molecules.

Triphenylamine-substituted zinc porphyrin nanoparticles with photodynamic/photothermal activity for cancer phototherapy in vitro

An amphiphilic zinc porphyrin complex with a typical donor–acceptor (D–A) structure was synthesized, where the triphenylamine acted as a donor unit while the porphyrin was used as an electronic acceptor. Due to the presence of triethylene glycol moieties on the parent structure, Zn-TPAP could spontaneously assemble to the related nanoparticles (Zn-TPAP NPs) with improved hydrophilicity. The as-prepared Zn-TPAP NPs presented relatively uniform spherical particles with the average particle sizes around 160 nm, which was suitable for tumor accumulation benefiting from the EPR effect. Due to the aggregation of the porphyrin molecules in the assembled nanostructures, Zn-TPAP NPs displayed broadened and red-shifted absorption and quenched fluorescence relative to that of Zn-TPAP. In addition to ROS generation, Zn-TPAP NPs exhibited moderate photothermal effects and the photothermal conversion efficiency was measured as 29%. Zn-TPAP NPs showed good biocompatibility and could generate ROS in the A549 cells. Under light irradiation, Zn-TPAP NPs can efficiently kill cancer cells. Thus, Zn-TPAP NPs could be used as potential nanoagents for cancer treatment through the photothermal/photodynamic synergistic modes.

Palladium porphyrin complexes for photodynamic cancer therapy: effect of porphyrin units and metal

The ROS generation ability and photocytotoxicity of the synthesized porphyrin compounds were enhanced with the number of porphyrin units in the photosensitizers.