Tumor delivery of Photofrin® by PLL-g-PEG for photodynamic therapy

Biomimetic Materials Based on Poly-3-hydroxybutyrate and Chlorophyll Derivatives

Electrospinning of biomimetic materials is of particular interest due to the possibility of producing flexible layers with highly developed surfaces from a wide range of polymers. Additionally, electrospinning is characterized by a high simplicity of implementation and the ability to modify the produced fibrous materials, which resemble structures found in living organisms. This study explores new electrospun materials based on polyhydroxyalkanoates, specifically poly-3-hydroxybutyrate, modified with chlorophyll derivatives. The research investigates the impact of chlorophyll derivatives on the morphology, supramolecular structure, and key properties of nonwoven materials. The obtained results are of interest for the development of new flexible materials with low concentrations of chlorophyll derivatives.

Enhanced Permeability and Retention Effect: A key facilitator for solid tumor targeting by nanoparticles

Exploring the enhanced permeability and retention (EPR) effect through therapeutic nanoparticles has been a subject of considerable interest in tumor biology. This passive targeting based phenomenon exploits the leaky blood vasculature and the defective lymphatic drainage system of the heterogeneous tumor microenvironment resulting in enhanced preferential accumulation of the nanoparticles within the tumor tissues. This article reviews the fundamental studies to assess how the EPR effect plays an essential role in passive targeting. Further, it summarizes various therapeutic modalities of nanoformulation including chemo-photodynamic therapy, intravascular drug release, and photothermal immunotherapy to combat cancer using enhanced EPR effect in neoplasia region.

Recent Advance of Nanomaterial-Mediated Tumor Therapies in the Past Five Years

Cancer has posed a major threat to human life and health with a rapidly increasing number of patients. The complexity and refractory of tumors have brought great challenges to tumor treatment. In recent years, nanomaterials and nanotechnology have attracted more attention and greatly improved the efficiency of tumor therapies and significantly prolonged the survival period, whether for traditional tumor treatment methods such as radiotherapy, or emerging methods, such as phototherapy and immunotherapy, sonodynamic therapy, chemodynamic therapy and RNA interference therapeutics. Various monotherapies have obtained positive results, while combination therapies are further proposed to prevent incomplete eradication and recurrence of tumors, strengthen tumor killing efficacy with minimal side effects. In view of the complementary promotion effects between different therapies, it is vital to utilize nanomaterials as the link between monotherapies to achieve synergistic performance. Further development of nanomaterials with efficient tumor-killing effect and better biosafety is more in line with the needs of clinical treatment. In a word, the development of nanomaterials provides a promising way for tumor treatment, and here we will review the emerging nanomaterials towards radiotherapy, phototherapy and immunotherapy, and summarized the developed nanocarriers applied for the tumor combination therapies in the past 5 years, besides, the advances of some other novel therapies such as sonodynamic therapy, chemodynamic therapy, and RNA interference therapeutics have also been mentioned.

RBC-derived nanosystem with enhanced ferroptosis triggered by oxygen-boosted phototherapy for synergized tumor treatment

Photodynamic and ferroptosis therapies for cancer treatment are restricted by the scarcity of oxygen and Fe in cancer cells, and the complicated structure of delivery systems. Herein, a red blood cell-derived vehicle (RDV) inherently enriched with hemoglobin co-delivers a photosensitizer, Ce6, and a ferroptosis promoter, sorafenib (SRF) into cancer cells for boosting oxygen and providing iron, which leads to enhanced PDT and stronger ferroptosis therapy. Damage to the RDV membrane under local irradation leads to SRF release at the tumor site for tumor-targeted therapy. The lipid membrane of the RDV could also improve the drug delivery efficiency in vitro and in vivo. The novel nanosystem exhibited enhanced tumor killing efficacy and improved safety compared with traditional PDT and ferroptosis therapy.

Photosensitizer-Functionalized Nanocomposites for Light-Activated Cancer Theranostics

Photosensitizers (PSs) have received significant attention recently in cancer treatment due to its theranostic capability for imaging and phototherapy. These PSs are highly responsive to light source of a suitable wavelength for image-guided cancer therapy from generated singlet oxygen and/or thermal heat. Various organic dye PSs show tremendous attenuation of tumor cells during cancer treatment. Among them, porphyrin and chlorophyll-based ultraviolet-visible (UV-Vis) dyes are employed for photodynamic therapy (PDT) by reactive oxygen species (ROS) and free radicals generated with 400-700 nm laser lights, which have poor tissue penetration depth. To enhance the efficacy of PDT, other light sources such as red light laser and X-ray have been suggested; nonetheless, it is still a challenging task to improve the light penetration depth for deep tumor treatment. To overcome this deficiency, near infrared (NIR) (700-900 nm) PSs, indocyanine green (ICG), and its derivatives like IR780, IR806 and IR820, have been introduced for imaging and phototherapy. These NIR PSs have been used in various cancer treatment modality by combining photothermal therapy (PTT) and/or PDT with chemotherapy or immunotherapy. In this review, we will focus on the use of different PSs showing photothermal/photodynamic response to UV-Vis or NIR-Vis light. The emphasis is a comprehensive review of recent smart design of PS-loaded nanocomposites for targeted delivery of PSs in light-activated combination cancer therapy.

The simultaneous role of porphyrins' H- and J- aggregates and host-guest chemistry on the fabrication of reversible Dextran-PMMA polymersome

Aggregation-induced quenching of porphyrin molecules as photosensitizer significantly reduces the quantum yield of the singlet oxygen generation, and it is able to decrease the efficacy of photodynamic therapy. We utilized amphiphilic copolymers in this work to precisely control porphyrin H-type and J-type aggregations in water. The amphiphilic copolymer bearing azobenzene, β-cyclodextrin, and porphyrin was successfully synthesized by the atom transfer radical polymerization technique. The azobenzene and β-cyclodextrin complex, as a host-guest supramolecular interaction, has great potential in the design of light-responsive nanocarriers. The amphiphilic block copolymer can be self-assembled into polymersomes, whose application in the generation of singlet oxygen has been also tested. We further demonstrate that, due to the stable H- and J-aggregates of porphyrin, which act as noncovalent cross-linking points, the structure of polymersomes can be reversible under light-stimulus. This formation method has the advantage of allowing for both the encapsulation of hydrophilic and hydrophobic molecules and release upon external light without any distinguishable changes in the structure. Furthermore, the morphology and particle size distribution of the polymersomes were also investigated by using transition electron microscopy, dynamic light scattering, and field emission scanning electron microscopy.

Multifunctional nanoparticles as photosensitizer delivery carriers for enhanced photodynamic cancer therapy

Photodynamic therapy (PDT) is an emerging cancer treatment combining light, oxygen, and a photosensitizer (PS) to produce highly cytotoxic reactive oxygen species that cause cancer cell death. However, most PSs are hydrophobic molecules that have poor water solubility and cannot target tumor tissues, causing damage to normal tissues and cells during PDT. Thus, there is a substantial demand for the development of nanocarrier systems to achieve targeted delivery of PSs into tumor tissues and cells. This review summarizes the research progress in PS delivery systems for PDT treatment of tumors and focuses on the recent design and development of multifunctional nanoparticles as PS delivery carriers for enhanced PDT. These multifunctional nanoparticles possess unique properties, including tunable particle size, changeable shape, stimuli-responsive PS activation, controlled PS release, and hierarchical targeting capability. These properties can increase tumor accumulation, penetration, and cellular internalization of nanoparticles to achieve PS activation and/or release in cancer cells for enhanced PDT. Finally, recent developments in multifunctional nanoparticles for tumor-targeted PS delivery and their future prospects in PDT are discussed.

The feasibility of using Saffron to reduce the photosensitivity reaction of selected photosensitizers using red blood cells and staphylococcusAureus bacteria as targets

BACKGROUND

The photosensitivity reaction which appears after a Photodynamic therapy treatment session is a challenge that needs further investigation. The goal of this research is to evaluate the possibility of using saffron to reduce or control this photosensitivity reaction and to present mathematical modeling of the cell survival curves and their dependency on saffron concentration.

METHODS

Red blood cells (RBC) and Staphylococcus aureus Bacteria (STB) were used as targets in this study. The Photosensitivity of Rose Bengali, Methylene Blue, and Photofrin independently and incorporated with saffron was investigated for continued irradiation at different Saffron concentrations. Gompertz's function was used to fit the survival curve parameters. The 50% cell survival rate was fit to an empirical formula based on Saffron concentrations.

RESULTS

Saffron inhibits the photosensitivity reaction of the three photosensitizers and causes a significant increase in the 50% survival rate time (t₅₀) for RBC`s and STB. Saffron didn't show phototoxicity when incubated alone with RBC`s and STB. The survival curve parameters of the RBCs and STB showed a good fit to the Gompertz function. Saffron concentration is related to the RBC`s t₅₀ based on power dependency of 0.56, 0.38 and 0.31 for Photofrin, Methylene Blue and Rose Bengali respectively and 0.1 on STB for Rose Bengali.

CONCLUSION

Saffron can efficiently be used to reduce the photosensitivity reaction of Photosensitizers after a PDT treatment session. Gompertz function was found to be an appropriate mathematical model for survival rate curves. The t₅₀ and the saffron concentration are well related through a power dependence empirical formula.

Turning Toxicants into Safe Therapeutic Drugs: Cytolytic Peptide-Photosensitizer Assemblies for Optimized In Vivo Delivery of Melittin

Melittin (MEL) is recognized as a highly potent therapeutic peptide for treating various human diseases including cancer. However, the clinical applications of MEL are largely restricted by its severe hemolytic activity and nonspecific cytotoxicity. Here, it is found that MEL can form a stable supramolecular nanocomplex of ≈60 nm with the photosensitizer chlorin e6 (Ce6), which after hyaluronic acid (HA) coating can achieve robust, safe, and imaging-guided tumor ablation. The as-designed nanocomplex (denoted as MEL/Ce6@HA) shows largely reduced hemolysis and selective cytolytic activity toward cancer cells. Upon laser irradiation, the loaded photosensitive Ce6 can synergistically facilitate the membrane-lytic efficiency of melittin and greatly increase the tumor penetration depth of the complexes in multicellular tumor spheroids. In vivo experiments reveal that MEL/Ce6@HA can realize enhanced tumor accumulation, reduced liver deposition, and rapid body clearance, which are beneficial for highly efficient and safe chemo-photodynamic dual therapy. This work develops a unique supramolecular strategy for optimized in vivo delivery of melittin and may have implications for the development of peptide-based theranostics.

Molecular and Biocompatibility Characterization of Red Blood Cell Membrane Targeted and Cell-Penetrating-Peptide-Modified Polymeric Nanoparticles

Red blood cells (RBCs) express a variety of immunomodulatory markers that enable the body to recognize them as self. We have shown that RBC membrane glycophorin A (GPA) receptor can mediate membrane attachment of protein therapeutics. A critical knowledge gap is whether attaching drug-encapsulated nanoparticles (NPs) to GPA and modification with cell-penetrating peptide (CPP) will impact binding, oxygenation, and the induction of cellular stress. The objective of this study was to formulate copolymer-based NPs containing model fluorescent-tagged bovine serum albumin (BSA) with GPA-specific targeting ligands such as ERY1 (ENPs), single-chain variable antibody (scFv TER-119, SNPs), and low-molecular-weight protamine-based CPP (LNPs) and to determine their biocompatibility using a variety of complementary high-throughput in vitro assays. Experiments were conducted by coincubating NPs with RBCs at body temperature, and biocompatibility was evaluated by Raman spectroscopy, hemolysis, complement lysis, and oxidative stress assays. Data suggested that LNPs effectively targeted RBCs, conferring 2-fold greater uptake in RBCs compared to ENPs and SNPs. Raman spectroscopy results indicated no adverse effect of NP attachment or internalization on the oxygenation status of RBCs. Cellular stress markers such as glutathione, malondialdehyde, and catalase were within normal limits, and complement-mediated lysis due to NPs was negligible in RBCs. Under the conditions tested, our data demonstrates that molecular targeting of the RBC membrane is a feasible translational strategy for improving drug pharmacokinetics and that the proposed high-throughput assays can prescreen diverse NPs for preclinical and clinical biocompatibility.

Self-Assembled Peptide- and Protein-Based Nanomaterials for Antitumor Photodynamic and Photothermal Therapy

Tremendous interest in self-assembly of peptides and proteins towards functional nanomaterials has been inspired by naturally evolving self-assembly in biological construction of multiple and sophisticated protein architectures in organisms. Self-assembled peptide and protein nanoarchitectures are excellent promising candidates for facilitating biomedical applications due to their advantages of structural, mechanical, and functional diversity and high biocompability and biodegradability. Here, this review focuses on the self-assembly of peptides and proteins for fabrication of phototherapeutic nanomaterials for antitumor photodynamic and photothermal therapy, with emphasis on building blocks, non-covalent interactions, strategies, and the nanoarchitectures of self-assembly. The exciting antitumor activities achieved by these phototherapeutic nanomaterials are also discussed in-depth, along with the relationships between their specific nanoarchitectures and their unique properties, providing an increased understanding of the role of peptide and protein self-assembly in improving the efficiency of photodynamic and photothermal therapy.

Nanoparticle Attachment to Erythrocyte Via the Glycophorin A Targeted ERY1 Ligand Enhances Binding without Impacting Cellular Function

PURPOSE

Nanoparticle (NP) attachment to biocompatible secondary carriers such as red blood cell (RBC) can prolong blood residence time of drug molecules and help create next-generation nanotherapeutics. However, little is known about the impact of RBC-targeted NPs on erythrocyte function.

METHODS

The objectives of this study were to develop and characterize in vitro a novel poly-L-lysine (PLL) and polyethylene glycol (PEG) copolymer-based NP containing fluorescent-tagged bovine serum albumin (BSA), and conjugated with ERY1, a 12 amino acid peptide with high affinity for the RBC membrane protein glycophorin A (ENP).

RESULTS

Confocal and flow cytometry data suggest that ENPs efficiently and irreversibly bind to RBC, with approximately 70% of erythrocytes bound after 24 h in a physiologic flow loop model compared to 10% binding of NPs without ERY1. Under these conditions, synthesized ENPs were not toxic to the RBCs. The rheological parameters at the applied shear. (0-15 Pa) were not influenced by ENP attachment to the RBCs. However, at high concentration, the strong affinity of ENPs to the glycophorin-A reduced the deformability of the RBC.

CONCLUSIONS

ENPs can be efficiently attached to the RBCs without adversely affecting cellular function, and this may potentially enhance circulatory half-life of drug molecules.

Redox-responsive supramolecular amphiphiles based on a pillar[5]arene for enhanced photodynamic therapy

Supramolecular amphiphiles based on a pillar[5]arene with enhanced photodynamic therapy have been fabricated.

Tumor-targeting, enzyme-activated nanoparticles for simultaneous cancer diagnosis and photodynamic therapy

Specific targeting towards tumors and the on-site activation of photosensitizers to diagnose tumors and reduce side effects for patients are currently the main challenges for photodynamic therapy (PDT) in the clinic. Herein, uniform diiodostyryl bodipy conjugated hyaluronic acid nanoparticles (DBHA-NPs) were successfully synthesized. The evaluation of their PDT effect at both a cellular level and in animal models of tumor-bearing mice shows that the DBHA-NPs present a remarkable suppression of tumorous growth due to their specific targeting and enhanced permeability and retention (EPR) effect. More importantly, the enzyme-activated "self-assembly and disaggregation" behavior in tumors can lead to the on-site activation of DBHA-NPs, which can diagnose the tumor exactly and reduce the side effects for patients significantly. These findings confirm that DBHA-NPs have significant potential for photodynamically activated cancer theranostics in a clinical setting.

Inter-polyelectrolyte nano-assembly induces folding and activation of functional peptides

Insufficient solubility, fragile folding structure and short half-life frequently hamper use of peptides as biological reagents or therapies. To enhance the peptide function, the effect of complexation of the peptides with ionic graft copolymers with water-soluble graft chains was tested in this study. Amphiphilic anionic peptide E5 acquires membrane disrupting activity at acidic pH due to folding from the random coil state to an ordered α-helical structure. Aggregation and imprecise folding of the peptide limited membrane disrupting activity of the peptide. In the presence of a cationic graft copolymer, E5 and its analogs adopted an ordered conformation without aggregation. The mixture of the peptides and the copolymer functioned more efficiently than peptide alone at not only acidic pH but also neutral pH at which the peptide alone had no activity. Similarly, a cationic peptide was successfully folded and activated by an anionic graft copolymer. Thus, our analysis indicated that spontaneous nano-assembly of ionic peptides with graft copolymers having opposite ionic charges triggers the folding of peptides without loss of solubility, leading to enhanced bioactivity.

Amphiphilic trismethylpyridylporphyrin-fullerene (C70) dyad: an efficient photosensitizer under hypoxia conditions

Amphiphilic trismethylpyridylporphyrin-C₇₀(PC₇₀) dyad with improved photosensitization has been successfully prepared.

Photocontrollable release and enhancement of photodynamic therapy based on host–guest supramolecular amphiphiles

A light-controlled porphyrinic photosensitizer release system was developed based on host–guest TPP–Azo/PEG–β-CD supramolecular amphiphiles, which could significantly enhance the efficiency of photodynamic therapy.

Current advances in polymer-based nanotheranostics for cancer treatment and diagnosis

Nanotheranostics is a relatively new, fast-growing field that combines the advantages of treatment and diagnosis via a single nanoscale carrier. The ability to bundle both therapeutic and diagnostic capabilities into one package offers exciting prospects for the development of novel nanomedicine. Nanotheranostics can deliver treatment while simultaneously monitoring therapy response in real-time, thereby decreasing the potential of over- or under-dosing patients. Polymer-based nanomaterials, in particular, have been used extensively as carriers for both therapeutic and bioimaging agents and thus hold great promise for the construction of multifunctional theranostic formulations. Herein, we review recent advances in polymer-based systems for nanotheranostics, with a particular focus on their applications in cancer research. We summarize the use of polymer nanomaterials for drug delivery, gene delivery, and photodynamic therapy, combined with imaging agents for magnetic resonance imaging, radionuclide imaging, and fluorescence imaging.

Perspectives on the application of nanotechnology in photodynamic therapy for the treatment of melanoma

Malignant melanoma is the most aggressive form of skin cancer and has been traditionally considered difficult to treat. The worldwide incidence of melanoma has been increasing faster than any other type of cancer. Early detection, surgery, and adjuvant therapy enable improved outcomes; nonetheless, the prognosis of metastatic melanoma remains poor. Several therapies have been investigated for the treatment of melanoma; however, current treatment options for patients with metastatic disease are limited and non-curative in the majority of cases. Photodynamic therapy (PDT) has been proposed as a promising minimally invasive therapeutic procedure that employs three essential elements to induce cell death: a photosensitizer, light of a specific wavelength, and molecular oxygen. However, classical PDT has shown some drawbacks that limit its clinical application. In view of this, the use of nanotechnology has been considered since it provides many tools that can be applied to PDT to circumvent these limitations and bring new perspectives for the application of this therapy for different types of diseases. On that ground, this review focuses on the potential use of developing nanotechnologies able to bring significant benefits for anticancer PDT, aiming to reach higher efficacy and safety for patients with malignant melanoma.

A genetically-encoded KillerRed protein as an intrinsically generated photosensitizer for photodynamic therapy

Photodynamic therapy (PDT) has received considerable attention as a therapeutic treatment for cancer and other diseases; however, it is frequently accompanied by prolonged phototoxic reaction of the skin due to slow clearance of synthetic photosensitizers (PSs) administered externally. This study was designed to investigate the genetic use of pKillerRed-mem, delivered using complexes of chitosan (CS) and poly(γ-glutamic acid) (γPGA), to intracellularly express a membrane-targeted KillerRed protein that can be used as a potential PS for PDT. Following transfection with CS/pKillerRed/γPGA complexes, a red fluorescence protein of KillerRed was clearly seen at the cellular membranes. When exposed to green-light irradiation, the KillerRed-positive cells produced an excessive amount of reactive oxygen species (ROS) in a time-dependent manner. Data from viability assays indicate that ROS have an important role in mediating KillerRed-induced cytotoxicity, apoptosis, and anti-proliferation, suggesting that KillerRed can be used as an intrinsically generated PS for PDT treatments. Notably, the phototoxic reaction of KillerRed toward cells gradually became negligible over time, presumably because of its intracellular degradability. These experimental results demonstrate that this genetically encoded KillerRed is biodegradable and has potential for PDT-induced destruction of diseased cells.