Photo-triggered release of doxorubicin from liposomes formulated by amphiphilic phthalocyanines for combination therapy to enhance antitumor efficacy

Macrophage membrane-based biomimetic nanocarrier system for enhanced immune activation and combination therapy in liver cancer

Previous studies have demonstrated that the combination of photodynamic therapy, photothermal therapy and chemotherapy is highly effective in treating hepatocellular carcinoma (HCC). However, the clinical application of this approach has been hindered by the lack of efficient and low-toxicity drug delivery platforms. To address this issue, we developed a novel biomimetic nanocarrier platform named ZID@RM, which utilizes ZIF8 functional nanoparticles encapsulated with macrophage membrane and loaded with indocyanine green and doxorubicin. The bionic nanocarrier platform has good biocompatibility, reducing the risk of rapid clearance by macrophages and improving the targeting ability for HCC cells. Under the dual regulation of acidity and infrared light, ZID@RM stimulated the generation of abundant reactive oxygen species within HCC cells, induced tumor cell pyroptosis and promoted the release of damage-associated molecular patterns to induce immune responses. In the future, this technology platform has the potential to provide personalized and improved healthcare by using patients' own macrophage membranes to create an efficient drug delivery system for tumor therapy.Graphical abstract Scheme 1 Schematic representation of the synthesis of a biomimetic nanomedicine delivery platform (ZID@RM) and its application in tumor imaging-guided combination therapy.

Innovative Design Strategies Advance Biomedical Applications of Phthalocyanines

Owing to their long absorption wavelengths, high molar absorptivity, and tunable photosensitivity, phthalocyanines have been widely used in photodynamic therapy (PDT). However, phthalocyanines still face the drawbacks of poor targeting, "always-on" photosensitizing properties, and unsatisfactory therapeutic efficiency, which limit their wide applications in biomedical fields. Thus, new design strategies such as modification of targeting molecules, formation of nanoparticles, and activating photosensitizers are developed to improve the above defects. Notably, recent studies have shown that novel phthalocyanines are not only used in fluorescence imaging and PDT, but also in photoacoustic imaging, photothermal imaging, sonodynamic therapy, and photothermal therapy. This review focuses on recent design strategies, applications in biomedicine, and clinical development of phthalocyanines, providing ideas and references for the design and application of phthalocyanine, so as to promote their future transformation into clinical applications.

Comparing PVP and Polymeric Micellar Formulations of a PEGylated Photosensitizing Phthalocyanine by NMR and Optical Techniques

Phthalocyanines are ideal candidates as photosensitizers for photodynamic therapy (PDT) of cancer due to their favorable chemical and photophysical properties. However, their tendency to form aggregates in water reduces PDT efficacy and poses challenges in obtaining efficient forms of phthalocyanines for therapeutic applications. In the current work, polyvinylpyrrolidone (PVP) and micellar formulations were compared for encapsulating and monomerizing a water-soluble zinc phthalocyanine bearing four non-peripheral triethylene glycol chains (Pc1). 1H NMR spectroscopy combined with UV-vis absorption and fluorescence spectroscopy revealed that Pc1 exists as a mixture of regioisomers in monomeric form in dimethyl sulfoxide but forms dimers in an aqueous buffer. PVP, polyethylene glycol castor oil (Kolliphor RH40), and three different triblock copolymers with varying proportions of polyethylene and polypropylene glycol units (termed P188, P84, and F127) were tested as micellar carriers for Pc1. 1H NMR chemical shift analysis, diffusion-ordered spectroscopy, and 2D nuclear Overhauser enhancement spectroscopy was applied to monitor the encapsulation and localization of Pc1 at the polymer interface. Kolliphor RH40 and F127 micelles exhibited the highest affinity for encapsulating Pc1 in the micellar core and resulted in intense Pc1 fluorescence emission as well as efficient singlet oxygen formation along with PVP. Among the triblock copolymers, efficiency in binding and dimer dissolution decreased in the order F127 > P84 > P188. PVP was a strong binder for Pc1. However, Pc1 molecules are rather surface-attached and exist as monomer and dimer mixtures. The results demonstrate that NMR combined with optical spectroscopy offer powerful tools to assess parameters like drug binding, localization sites, and dynamic properties that play key roles in achieving high host-guest compatibility. With the corresponding adjustments, polymeric micelles can offer simple and easily accessible drug delivery systems optimizing phthalocyanines' properties as efficient photosensitizers.

Advances in Liposome-Encapsulated Phthalocyanines for Photodynamic Therapy

This updated review aims to describe the current status in the development of liposome-based systems for the targeted delivery of phthalocyanines for photodynamic therapy (PDT). Although a number of other drug delivery systems (DDS) can be found in the literature and have been studied for phthalocyanines or similar photosensitizers (PSs), liposomes are by far the closest to clinical practice. PDT itself finds application not only in the selective destruction of tumour tissues or the treatment of microbial infections, but above all in aesthetic medicine. From the point of view of administration, some PSs can advantageously be delivered through the skin, but for phthalocyanines, systemic administration is more suitable. However, systemic administration places higher demands on advanced DDS, active tissue targeting and reduction of side effects. This review focuses on the already described liposomal DDS for phthalocyanines, but also describes examples of DDS used for structurally related PSs, which can be assumed to be applicable to phthalocyanines as well.

Soft nano and microstructures for the photomodulation of cellular signaling and behavior

Photoresponsive soft materials are everywhere in the nature, from human's retina tissues to plants, and have been the inspiration for engineers in the development of modern biomedical materials. Light as an external stimulus is particularly attractive because it is relatively cheap, noninvasive to superficial biological tissues, can be delivered contactless and offers high spatiotemporal control. In the biomedical field, soft materials that respond to long wavelength or that incorporate a photon upconversion mechanism are desired to overcome the limited UV-visible light penetration into biological tissues. Upon light exposure, photosensitive soft materials respond through mechanisms of isomerization, crosslinking or cleavage, hyperthermia, photoreactions, electrical current generation, among others. In this review, we discuss the most recent applications of photosensitive soft materials in the modulation of cellular behavior, for tissue engineering and regenerative medicine, in drug delivery and for phototherapies.

Pegylated metal-free and zinc(II) phthalocyanines: synthesis, photophysicochemical properties and in vitro photodynamic activities against head, neck and colon cancer cell lines

In this study, a series of peripherally and non-peripherally tetra-substituted metal-free and zinc(II) phthalocyanines were successfully prepared in good yields by cyclotetramerization of the phthalonitrile derivative bearing a tetraethylene glycol methyl ether group at 3- and 4- positions. All newly synthesized compounds were characterized using spectroscopic methods, such as FT-IR, NMR, mass and UV-Vis spectroscopy. To determine the therapeutic potential of the synthesized phthalocyanines, the effects of the substitution pattern (peripheral and non-peripheral) and central metal atom on the photophysicochemical properties were investigated. When comparing their singlet oxygen generation capabilities (Φ_Δ), metallo-phthalocyanine derivatives with zinc (0.73 for 1b and 0.70 for 2b) showed higher singlet oxygen yield than metal-free derivatives (0.21 for 1a and 0.12 for 2a) in DMSO. The photodynamic therapy activities of the water-soluble phthalocyanines were tested via in vitro studies using the A253, FaDu (head and neck cancer cell lines), and HT29 (colon cancer) cell lines. The strongest photodynamic activity was found in 1b and 2b molecules with a metal core among the four molecules studied. The results suggested that the non-peripherally tetra-substituted 1b molecule was regarded as a suitable photodynamic therapy agent due to its light cytotoxicity and secondary impact induced by ROS production.

The effect of charge on Zn tetra morpholine porphyrin conjugated to folic acid-nitrogen doped graphene quantum dots for photodynamic therapy studies

Zinc tetra morpholine porphyrin (complex 2), and its quaternized derivative (complex 3) were synthesized and conjugated to folic acid nitrogen doped graphene quantum dots (FA-NGQDs) through π-π stacking to study their photodynamic therapy (PDT) efficacy. Photophysiochemical properties of complexes 2, 3, and their conjugates (2-FA-NGQDs, 3-FA-NGQDs) were studied. It was found that complex 3 had higher ϕ_Δ of 0.56 compared to complex 2 with ϕ_Δ of 0.24, and respective composites: 3-FA-NGQDs had higher ϕ_Δ compared to 2-FA-NGQDs. The PDT studies were conducted for nanoparticles (FA-NGQDs), complexes (2, 3), and respective composites (2-FA-NGQDs, and 3-FA-NGQDs) using MCF-7 breast cancer cell. Dark toxicity of all compounds was above 90% which is negligible. At a highest concentration of 40 µg/mL, 3-FA-NGQDs gave the lowest cell viability of 28% compared to all other conjugates and porphyrins alone.

Expanding the applications of photodynamic therapy-tooth bleaching

OBJECTIVES

The current tooth bleaching materials are associated with adverse effect. Photodynamic method based on a novel photosensitizer alone, without combining with peroxides, is evaluated for tooth bleaching application.

MATERIALS AND METHODS

Teeth samples were randomly divided into 3 groups with different treatment schemes, including negative control group (group A, physiological saline), experimental group (group B, ZnPc(Lys)5), and the positive control group (group C, hydrogen peroxide). Tooth color, surface microhardness, and roughness were determined at baseline, right after the first and second phase of bleaching, as well as 1 week and 1 month post-bleaching. Four samples in each group was randomly selected to evaluate the changes in surface morphology using the scanning electron microscope.

RESULTS

The color change values (ΔE) in group B (7.10 ± 1.03) and C (12.22 ± 2.35) were significantly higher than that in group A (0.93 ± 0.30, P < 0.05). Additionally, surface microhardness and roughness were significantly affected in group C, but not in the group A and B. Furthermore, the scanning electron microscope images showed no adverse effect of enamel in the group A and B while the group C demonstrated corrosive changes.

CONCLUSIONS

ZnPc(Lys)5 had a satisfactory bleaching effect and is promising to be a new type of tooth bleaching agent.

CLINICAL RELEVANCE

The current tooth bleaching materials give a satisfactory clinical outcome and long-term stability, but associated with some adverse reactions. Photosenstizer ZnPc(Lys)5 eliminated the main side effects observed in hydrogen peroxide-based agents on the enamel, and also had a satisfactory bleaching effect and provide a novel selective bleaching scheme for clinical use.

NIR Photosensitizer for Two-Photon Fluorescent Imaging and Photodynamic Therapy of Tumor

Preparation of near-infrared (NIR) emissive fluorophore for imaging-guided PDT (photodynamic therapy) has attracted enormous attention. Hence, NIR photosensitizers of two-photon (TP) fluorescent imaging and photodynamic therapy are highly desirable. In this contribution, a novel D-π-A structured NIR photosensitizer (TTRE) is synthesized. TTRE demonstrates near-infrared (NIR) emission, good biocompatibility, and superior photostability, which can act as TP fluorescent agent for clear visualization of cells and vascular in tissue with deep-tissue penetration. The PDT efficacy of TTRE as photosensitizer is exploited in vitro and in vivo. All these results confirm that TTRE would serve as potential platform for TP fluorescence imaging and imaging-guided photodynamic therapy.

Non-Oncologic Applications of Nanomedicine-Based Phototherapy

Phototherapy is widely applied to various human diseases. Nanomedicine-based phototherapy can be classified into photodynamic therapy (PDT) and photothermal therapy (PTT). Activated photosensitizer kills the target cells by generating radicals or reactive oxygen species in PDT while generating heat in PTT. Both PDT and PTT have been employed for treating various diseases, from preclinical to randomized controlled clinical trials. However, there are still hurdles to overcome before entering clinical practice. This review provides an overview of nanomedicine-based phototherapy, especially in non-oncologic diseases. Multiple clinical trials were undertaken to prove the therapeutic efficacy of PDT in dermatologic, ophthalmologic, cardiovascular, and dental diseases. Preclinical studies showed the feasibility of PDT in neurologic, gastrointestinal, respiratory, and musculoskeletal diseases. A few clinical studies of PTT were tried in atherosclerosis and dry eye syndrome. Although most studies have shown promising results, there have been limitations in specificity, targeting efficiency, and tissue penetration using phototherapy. Recently, nanomaterials have shown promising results to overcome these limitations. With advanced technology, nanomedicine-based phototherapy holds great potential for broader clinical practice.