Hypericin-loaded nanoparticles for the photodynamic treatment of ovarian cancer

Hypericin supramolecular assembles: A way to increase the skin availability and photodynamic efficiency in tumor cells

Cyclodextrins (CDs) are molecules approved by the FDA and show promise in increasing the solubility of hydrophobic molecules and making them more available to the skin. These CDs have been used to form complexes with some photosensitizers for Photodynamic Therapy (PDT), such as Hypericin (HY). HY is a lipophilic photosensitizer known for its exceptional fluorescence and singlet oxygen quantum yield generation of over 20 % under 590 nm irradiation. In this study, we found a six-fold increase in the release of HY in vitro after complexation with β-CD. The β-CDHY assembly also demonstrated better skin retention, which is crucial for the topical application of this photosensitizer. Furthermore, the β-CD complexation led to a significant increase in the phototoxicity of HY at three different light doses (3, 6, and 10 J cm-2) due to its improved water solubility and higher in vitro accumulation (approximately two times compared with free HY) in HeLa and Vero cell lines.

The use of nanomaterials in advancing photodynamic therapy (PDT) for deep-seated tumors and synergy with radiotherapy

Photodynamic therapy (PDT) has been under development for at least 40 years. Multiple studies have demonstrated significant anti-tumor efficacy with limited toxicity concerns. PDT was expected to become a major new therapeutic option in treating localized cancer. However, despite a shifting focus in oncology to aggressive local therapies, PDT has not to date gained widespread acceptance as a standard-of-care option. A major factor is the technical challenge of treating deep-seated and large tumors, due to the limited penetration and variability of the activating light in tissue. Poor tumor selectivity of PDT sensitizers has been problematic for many applications. Attempts to mitigate these limitations with the use of multiple interstitial fiberoptic catheters to deliver the light, new generations of photosensitizer with longer-wavelength activation, oxygen independence and better tumor specificity, as well as improved dosimetry and treatment planning are starting to show encouraging results. Nanomaterials used either as photosensitizers per se or to improve delivery of molecular photosensitizers is an emerging area of research. PDT can also benefit radiotherapy patients due to its complementary and potentially synergistic mechanisms-of-action, ability to treat radioresistant tumors and upregulation of anti-tumoral immune effects. Furthermore, recent advances may allow ionizing radiation energy, including high-energy X-rays, to replace external light sources, opening a novel therapeutic strategy (radioPDT), which is facilitated by novel nanomaterials. This may provide the best of both worlds by combining the precise targeting and treatment depth/volume capabilities of radiation therapy with the high therapeutic index and biological advantages of PDT, without increasing toxicities. Achieving this, however, will require novel agents, primarily developed with nanomaterials. This is under active investigation by many research groups using different approaches.

Photoactive Parietin-loaded nanocarriers as an efficient therapeutic platform against triple-negative breast cancer

The application of photodynamic therapy has become more and more important in combating cancer. However, the high lipophilic nature of most photosensitizers limits their parenteral administration and leads to aggregation in the biological environment. To resolve this problem and deliver a photoactive form, the natural photosensitizer parietin (PTN) was encapsulated in poly(lactic-co-glycolic acid) nanoparticles (PTN NPs) by emulsification diffusion method. PTN NPs displayed a size of 193.70 nm and 157.31 nm, characterized by dynamic light scattering and atomic force microscopy, respectively. As the photoactivity of parietin is essential for therapy, the quantum yield of PTN NPs and the in vitro release were assessed. The antiproliferative activity, the intracellular generation of reactive oxygen species, mitochondrial potential depolarization, and lysosomal membrane permeabilization were evaluated in triple-negative breast cancer cells (MDA-MB-231 cells). At the same time, confocal laser scanning microscopy (CLSM) and flow cytometry were used to investigate the cellular uptake profile. In addition, the chorioallantoic membrane (CAM) was employed to evaluate the antiangiogenic effect microscopically. The spherical monomodal PTN NPs show a quantum yield of 0.4. The biological assessment on MDA-MB-231 cells revealed that free PTN and PTN NPs inhibited cell proliferation with IC50 of 0.95 µM and 1.9 µM at 6 J/cm2, respectively, and this can be attributed to the intracellular uptake profile as proved by flow cytometry. Eventually, the CAM study illustrated that PTN NPs could reduce the number of angiogenic blood vessels and disrupt the vitality of xenografted tumors. In conclusion, PTN NPs are a promising anticancer strategy in vitro and might be a tool for fighting cancer in vivo.

The Application of Nanoparticle-Based Imaging and Phototherapy for Female Reproductive Organs Diseases

Various female reproductive disorders affect millions of women worldwide and bring many troubles to women's daily life. Let alone, gynecological cancer (such as ovarian cancer and cervical cancer) is a severe threat to most women's lives. Endometriosis, pelvic inflammatory disease, and other chronic diseases-induced pain have significantly harmed women's physical and mental health. Despite recent advances in the female reproductive field, the existing challenges are still enormous such as personalization of disease, difficulty in diagnosing early cancers, antibiotic resistance in infectious diseases, etc. To confront such challenges, nanoparticle-based imaging tools and phototherapies that offer minimally invasive detection and treatment of reproductive tract-associated pathologies are indispensable and innovative. Of late, several clinical trials have also been conducted using nanoparticles for the early detection of female reproductive tract infections and cancers, targeted drug delivery, and cellular therapeutics. However, these nanoparticle trials are still nascent due to the body's delicate and complex female reproductive system. The present review comprehensively focuses on emerging nanoparticle-based imaging and phototherapies applications, which hold enormous promise for improved early diagnosis and effective treatments of various female reproductive organ diseases.

Photoactivity of hypericin: from natural product to antifungal application

Considering the multifaceted and increasing application of photodynamic therapy (PDT), in recent years the antimicrobial employment of this therapy has been highlighted, because of the antiviral, antibacterial, antiparasitic, and antifungal activities that have already been demonstrated. In this context, research focussed on antimycological action, especially for treatment of superficial infections, presents promising growth due to the characteristics of these infections that facilitate PDT application as new therapeutic options are needed in the field of medical mycology. Among the more than one hundred classes of photosensitizers the antifungal action of hypericin (Hyp) stands out due to its ability to permeate the lipid membrane and accumulate in different cytoplasmic organelles of eukaryotic cells. In this review, we aim to provide a complete overview of the origin, physicochemical characteristics, and optimal alternative drug deliveries that promote the photodynamic action of Hyp (Hyp-PDT) against fungi. Furthermore, considering the lack of a methodological consensus, we intend to compile the best strategies to guide researchers in the antifungal application of Hyp-PDT. Overall, this review provides a future perspective of new studies and clinical possibilities for the advances of such a technique in the treatment of mycoses in humans.

Enhancement of hypericin nanoparticle-mediated sonoinduced disruption of biofilm and persister cells of Streptococcus mutans by dermcidin-derived peptide DCD-1L

BACKGROUND

Streptococcus mutans is considered a major significant contributor to dental caries and its effective removal is difficult due to the formation of biofilm. Therefore, the development of adjuvant therapeutic strategies with anti-biofilm properties is a promising approach. In the present study, we examined the effect of dermcidin-derived peptide DCD-1 L on the antibacterial activity of hypericin nanoparticle (HypNP)-mediated antimicrobial sonodynamic therapy (aSDT) against persister cells growing- and biofilm cultures of S. mutans.

MATERIALS AND METHODS

Following synthesis and confirmation of HypNP, the fractional inhibitory concentration (FIC) index of HypNP and DCD-1 L was determined by checkerboard assay. Cellular uptake of HypNP-DCD-1 L and generation of endogenous reactive oxygen species (ROS) were assessed and followed by the determination of antimicrobial sonoactivity of HypNP-DCD-1 L against persister cells growing- and biofilm cultures of S. mutans. The water-insoluble extracellular polysaccharide (EPS) and expression of the gtfD, comDE, and smuT genes were then evaluated in persister cells growing- and biofilm cultures of S. mutans.

RESULTS

There was a synergistic activity in the combination of HypNP and DCD-1 L against S. mutans with an FIC index value of 0.37. The HypNP-DCD-1L-mediated aSDT also displayed the highest cellular uptake and endogenous ROS generation by bacterial cells. When biofilm and persister cells of S. mutans were treated with HypNP-DCD-1 L and subsequently exposed to ultrasound waves, 5.1 log and 3.8 log reductions, respectively, in bacterial numbers were observed (P<0.05). According to the data, EPS in both persister cells growing- and biofilm cultures of S. mutans were significantly decreased after exposure to the HypNP-DCD-1L-mediated aSDT (P<0.05). In addition, the quantitative real-time PCR data illustrated the high level of similarities in very low-expression profiles of the gtfD before and after all treated groups for persister cells. While, following HypNP-DCD-1L-mediated aSDT treatment, the expression levels of gtfD, comDE, and smuT were significantly lower in treated persister cells growing- and biofilm cultures of S. mutans in comparison with control groups (P<0.05).

CONCLUSIONS

Combined, the results of this study indicate that ultrasound waves-activated HypNP-DCD-1 L can sonoinactivate S. mutans biofilms and persister cells, as well as reduce effectively pathogenicity potency of S. mutans. Hence, HypNP-DCD-1L-mediated aSDT may be proposed as a promising adjunctive therapeutic approach for dental caries.

Antimicrobial activity of D-amino acid in combination with photo-sonoactivated hypericin nanoparticles against Acinetobacter baumannii

BACKGROUND

The emergence of multidrug-resistant Acinetobacter baumannii strains is increasing worldwide. To overcome these life-threatening infections, the development of new treatment approaches is critical. For this purpose, this study was conducted to determine the antimicrobial photo-sonodynamic therapy (aPSDT) using hypericin nanoparticles (HypNP) in combination with D-Tryptophan (D-Trp) against A. baumannii.

MATERIALS AND METHODS

HypNP was synthesized and characterized, followed by the determination of the fractional inhibitory concentration (FIC) index of HypNP and D-Trp by checkerboard assay. Next, the antimicrobial and anti-biofilm potential of HypNP@D-Trp-mediated aPSDT against A. baumannii was evaluated. Finally, the anti-virulence activity of aPSDT using HypNP@D-Trp was accessed following the characterization of HypNP@D-Trp interaction with AbaI using in silico virtual screening and molecular docking.

RESULTS

A synergistic activity in the combination of HypNP and D-Trp against A. baumannii was observed with a FIC index value of 0.5. There was a 5.10 log₁₀ CFU/mL reduction in the cell viability of A. baumannii when the bacterial cells were treated with 1/2 × MIC of HypNP@D-Trp and subsequently exposed to ultrasound waves and blue light (P < 0.05). Moreover, a significant biofilm degradation effect on biofilm-associated cells of A. baumannii was observed after treatment with aPSDT using 2 × MIC of HypNP@D-Trp in comparison with the control groups (P < 0.05). According to the molecular docking analysis of the protein-ligand complex, Hyp with a high affinity for AbaI showed a binding affinity of - 9.41 kcal/mol. Also, the expression level of abaI gene was significantly downregulated by 10.32-fold in A. baumannii treated with aPSDT as comprised with the control group (P < 0.05).

CONCLUSIONS

It can be concluded that HypNP@D-Trp-mediated aPSDT can be considered a promising strategy to overcome the infections caused by A. baumannii by reducing the growth of bacterial biofilm and decreasing the expression of abaI as a gene involved in A. baumannii biofilm formation.

PLGA-based nanoparticles for the treatment of cancer: current strategies and perspectives

Research on cancer treatment is always of great importance because of the extensive and difficult treatment options and side effects of chemotherapeutic agents. Due to this, novel techniques for cancer treatment are the need of the day. Nowadays, nanotechnology is of great interest for its applications as diagnostic tools, theragnostic, contrasting agents, and vehicles for delivering drugs. Nanoparticles (NPs) are made up of biocompatible and biodegradable polymers that improve the pharmacokinetic and pharmacodynamic properties of drugs, reduce side effects, improve stability, prolong the release of drug, and reduce the dosing frequency. Poly (lactic-co-glycolic acid) (PLGA) is FDA-approved synthetic polymer which can be used to formulate NPs that can be targeted to a specific site for the safe and effective delivery of drugs. PLGA-based NPs can be used for a variety of cancer therapies including tumor-targeted drug delivery, gene therapy, hyperthermia, and photodynamic therapy. This article discusses the method of preparation, characterization, encapsulation of chemotherapeutic drugs, effect of physicochemical properties of PLGA- based NPs, and how we can exploit these aspects through various methods of preparation for drug loading, biodistribution, target specificity, and their use in cancer treatment. Along with these targeting strategies, gene therapy, cancer immunotherapy, and various applications have also been discussed. This article also aims to discuss the incorporation of diagnostic tools and therapeutic moiety in one versatile formulation of PLGA-NPs and the difficulties faced in translating this promising tool to clinical use.

Improved Hypericin solubility via β-cyclodextrin complexation: Photochemical and theoretical study for PDT applications

Hypericin (HY) is a lipophilic photosensitizer (PS) extensively employed for photodynamic therapy (PDT), presenting high absorption in the visible region, chemical and photostability, as well as a good triplet quantum yield. Supramolecular complexation of photosensitizers into cyclodextrins (CD) is promising to improve their poor solubility, compromising their bioavailability and upcoming applications in PDT. This research produced an inclusion complex between HY and β-CD through the co-solvent method. HY became soluble after inclusion into β-CD cavities, besides retaining its fluorescent and singlet oxygen quantum yields (ϕ_f =0.115 and ϕ_Δ= 0.23, respectively), which are essential parameters for PDT uses and are not reported in the literature. By the theoretical analysis, since ΔG < 0, it was easy to conclude that HY inclusion into β-CD is a spontaneous process. Additionally, the complexes presented no changes in excited states after complexation. β-CDHY was 27% more phototoxic than free HY when tested in MCF7 cells using 3 J cm^-2 of irradiation, indicating a better cell uptake of HY. These outcomes suggest that the inclusion complex of HY into β-CD has the potential for use in PDT.

Interaction effects between macromolecules and photosensitizer on the ability of AlPc and InPc-loaded PHB magnetic nanoparticles in photooxidatizing simple biomolecules

The parameters used in the preparation of polymeric nanoparticles can influence its ability to photooxidate biomolecules. This work evaluated the effects of four parameter to prepare Poly(3-hydroxybutyrate) (PHB) nanoparticle loaded with aluminum and indium phthalocyanine (AlPc and InPc), together with iron oxide nanoparticles, assessing their influence on the size, the entrapment efficiency, and the nanoparticles recovery efficacy. The capability of free, and encapsulated, AlPc and InPc in photooxidating the bovine serum albumin (BSA) and tryptophan (Trp) was monitored by fluorescence. The AlPc-loaded nanoparticles had a larger size and a greater entrapment efficiency than that obtained by InPc-loaded nanoparticles. The free InPc was more efficient than the free AlPc to photooxidize the BSA and Trp; whereas the encapsulated AlPc was more efficient than encapsulated InPc to photooxidize the biomolecules. The higher hydrophobicity of the AlPc, combined with the greater aggregation state and the major interaction with the BSA, quenching the capacity of the free AlPc to photooxidate the biomolecules; whereas the greater interaction of the AlPc with PHB reduce the aggregation effect on the free molecules in the aqueous phase and increase the entrapment efficiency, resulting in an improving of the photodynamic efficiency and an increase of the photooxidation rate constant.

Hollow microneedle assisted intradermal delivery of hypericin lipid nanocapsules with light enabled photodynamic therapy against skin cancer

Photodynamic therapy (PDT) to manage non-melanoma skin cancers has garnered great attention over the past few years. Hypericin (Hy) is a potent lipid-soluble photosensitiser with promising anticancer therapeutic activities. Nevertheless, its poor water-solubility, aggregation in biological systems and insufficient skin penetration restricted its effective exploitation. Herein, we report for the first-time encapsulation of Hy into lipid nanocapsules (Hy-LNCs), and then application of an AdminPen™ hollow microneedles (Ho-MNs) array and an in-house fabricated Ho-MN to enable efficient intradermal delivery. The physicochemical properties, photoactivity, ex vivo drug distribution and cellular uptake were evaluated. Results showed that Hy-LNCs were successfully formed with a particle size of 47.76 ± 0.49 nm, PDI of 0.12 ± 0.02, high encapsulation efficiency (99.67% ± 0.35), 396 fold higher photoactivity, 7 fold higher skin drug deposition, significantly greater cellular uptake and higher photocytotoxicity compared to free Hy. The therapeutic effect of Hy-LNCs was finally assessed in vivo using a nude mouse model with transplanted tumours. Interestingly, Hy-LNCs delivered by Ho-MN exhibited remarkable anti-tumour destruction (85.84%) after irradiation with 595 nm. This study showed that Ho-MNs-driven delivery of Hy-LNCs followed by irradiation could form a promising minimally invasive, effective and site-specific approach for managing non-melanoma skin cancers.

Recent advancements of nanoparticles application in cancer and neurodegenerative disorders: At a glance

Nanoscale engineering is one of the innovative approaches to heal multitudes of ailments, such as varieties of malignancies, neurological problems, and infectious illnesses. Therapeutics for neurodegenerative diseases (NDs) may be modified in aspect because of their ability to stimulate physiological response while limiting negative consequences by interfacing and activating possible targets. Nanomaterials have been extensively studied and employed for cancerous therapeutic strategies since nanomaterials potentially play a significant role in medical transportation. When compared to conventional drug delivery, nanocarriers drug delivery offers various benefits, such as excellent reliability, bioactivity, improved penetration and retention impact, as well as precise targeting and administering. Upregulation of drug efflux transporters, dysfunctional apoptotic mechanisms, and a hypoxic atmosphere are all elements that lead to cancer treatment sensitivity in humans. It has been possible to target these pathways using nanoparticles and increase the effectiveness of multidrug resistance treatments. As innovative strategies of tumor chemoresistance are uncovered, nanomaterials are being developed to target specific pathways of tumor resilience. Scientists have recently begun investigating the function of nanoparticles in immunotherapy, a field that is becoming increasingly useful in the care of malignancies. Nanoscale therapeutics have been explored in this scientific literature and represent the most current approaches to neurodegenerative illnesses and cancer therapy. In addition, current findings and various biomedical nanomaterials' future promise for tissue regeneration, prospective medication design, and the synthesis of novel delivery approaches have been emphasized.

Multifunctional Nanoplatforms as a Novel Effective Approach in Photodynamic Therapy and Chemotherapy, to Overcome Multidrug Resistance in Cancer

It is more than sixty years since the era of modern photodynamic therapy (PDT) for cancer began. Enhanced selectivity for malignant cells with a reduced selectivity for non-malignant cells and good biocompatibility along with the limited occurrence of side effects are considered to be the most significant advantages of PDT in comparison with conventional therapeutic approaches, e.g., chemotherapy. The phenomenon of multidrug resistance, which is associated with drug efflux transporters, was originally identified in relation to the application of chemotherapy. Unfortunately, over the last thirty years, numerous papers have shown that many photosensitizers are the substrates of efflux transporters, significantly restricting the effectiveness of PDT. The concept of a dynamic nanoplatform offers a possible solution to minimize the multidrug resistance effect in cells affected by PDT. Indeed, recent findings have shown that the utilization of nanoparticles could significantly enhance the therapeutic efficacy of PDT. Additionally, multifunctional nanoplatforms could induce the synergistic effect of combined treatment regimens, such as PDT with chemotherapy. Moreover, the surface modifications that are associated with nanoparticle functionalization significantly improve the target potential of PDT or chemo-PDT in multidrug resistant and cancer stem cells.

Herbal nanomedicines: Recent advancements, challenges, opportunities and regulatory overview

BACKGROUND

Herbal Nano Medicines (HNMs) are nano-sized medicine containing herbal drugs as extracts, enriched fractions or biomarker constituents. HNMs have certain advantages because of their increased bioavailability and reduced toxicities. There are very few literature reports that address the common challenges of herbal nanoformulations, such as selecting the type/class of nanoformulation for an extract or a phytochemical, selection and optimisation of preparation method and physicochemical parameters. Although researchers have shown more interest in this field in the last decade, there is still an urgent need for systematic analysis of HNMs.

PURPOSE

This review aims to provide the recent advancement in various herbal nanomedicines like polymeric herbal nanoparticles, solid lipid nanoparticles, phytosomes, nano-micelles, self-nano emulsifying drug delivery system, nanofibers, liposomes, dendrimers, ethosomes, nanoemulsion, nanosuspension, and carbon nanotube; their evaluation parameters, challenges, and opportunities. Additionally, regulatory aspects and future perspectives of herbal nanomedicines are also being covered to some extent.

METHODS

The scientific data provided in this review article are retrieved by a thorough analysis of numerous research and review articles, textbooks, and patents searched using the electronic search tools like Sci-Finder, ScienceDirect, PubMed, Elsevier, Google Scholar, ACS, Medline Plus and Web of Science.

RESULTS

In this review, the authors suggested the suitability of nanoformulation for a particular type of extracts or enriched fraction of phytoconstituents based on their solubility and permeability profile (similar to the BCS class of drugs). This review focuses on different strategies for optimising preparation methods for various HNMs to ensure reproducibility in context with all the physicochemical parameters like particle size, surface area, zeta potential, polydispersity index, entrapment efficiency, drug loading, and drug release, along with the consistent therapeutic index.

CONCLUSION

A combination of herbal medicine with nanotechnology can be an essential tool for the advancement of herbal medicine research with enhanced bioavailability and fewer toxicities. Despite the challenges related to traditional medicine's safe and effective use, there is huge scope for nanotechnology-based herbal medicines. Overall, it is well stabilized that herbal nanomedicines are safer, have higher bioavailability, and have enhanced therapeutic value than conventional herbal and synthetic drugs.

Thermosensitive liposomes encapsulating hypericin: Characterization and photodynamic efficiency

The potent photodynamic properties of Hypericin (Hyp) elicit a range of light-dose-dependent anti-tumor activities. However, its low water solubility hampers its broad application. Therefore, the administration of Hyp into biological systems requires drug carriers that would enable sufficient bioavailability. Stimuli-triggered nanocarriers, which are sensitive to endogenous or exogenous stimuli, have become an attractive replacement for conventional therapeutic regimens. Herein, we produced optimized Hyp thermosensitive liposomes (Hyp-TSL), self-assembled from DPPC, DSPC, DSPE-PEG2000. Hyp-TSL displayed a hydrodynamic diameter below 100 nm with an adequate encapsulation efficiency of 94.5 % and good colloidal stability. Hyp-TSL exhibited thermal sensitivity over a narrow range with a phase transition temperature of 41.1 °C, in which liposomal destruction was evident in AFM images after elevated temperature above the phase transition temperature. The uptake of TSL-Hyp into MDA-MB-231 cells was significantly increased with hyperthermic treatment of 42 °C when compared to the uptake at a average physiological temperature of 37 °C. Consequent enhancement of cellular reactive oxygen species was observed after hyperthermic treatment at 42 °C. The half-maximal inhibitory concentration of Hyp TSL was reduced by 3.8 fold after hyperthermic treatment at 42 °C in comparison to treatment at 37 °C. Hyp-TSL were considered safe for intravenous applications as compared by hemocompatibility studies, where coagulation time was <50 s and hemolytic potential was <10%. Conclusively, the enhancement in tumor drug availability correlated with improved therapeutic outcomes.

Hypericin-loaded oil-in-water nanoemulsion synthesized by ultrasonication process enhances photodynamic therapy efficiency

Hypericin (Hy) is a hydrophobic photosensitizer used in photodynamic therapy for cancer therapeutic. In this study, Hy-loaded oil-in-water (O/W) nanoemulsions (NEs) were produced by the ultrasonication method combing different biocompatible oils and surfactants to enhance Hy aqueous solubility and bioavailability. Experimental parameters were optimized by the characterization of droplet size, zeta potential, and physicochemical properties. In vitro studies based on the release profile, cytotoxicity, cell morphology, and Hy intracellular accumulation were assayed. Hy at 100 mg L^-1 was incorporated into the low viscosity (~0.005 Pa s) NEs with spherical droplets averaging 20-40 nm in size and polydispersity index <0.02. Hy release from the NE was significantly higher (4-fold) than its suspension (p < 0.001). The NEs demonstrated good physical stability during storage at 5 °C for at least six months. The Hy-loaded NEs exhibited an IC50 value 6-fold lower than Hy suspension during PDT against breast cancer cell lines (MCF-7). Cell microscopy imaging confirmed the increased cytotoxic effects of Hy-loaded NEs, showing damaged and apoptotic cells. Confocal laser scanning microscopy evidenced greater Hy delivery through NE into MCF-7 cells followed by improved intracellular ROS generation. Our results suggest that the Hy-loaded NEs can improve hypericin efficacy and assist Hy-PDT's preclinical development as a cancer treatment.

Hypericin in photobiological assays: An overview

Hypericin is considered a potent photosensitizer for use in antitumor and antimicrobial photodynamic therapy (PDT). This review presents the primary biological results obtained with hypericin in photodynamic therapy applications, such as photodynamic cancer treatment, photoinactivation of microorganisms (PDI), tissue scarring, and photo diagnosis. We present a compilation of in vitro results that have been published thus far; for these studies, we highlight the hypericin concentration, light dose, and other experimental conditions to evaluate the efficiency of photodynamic treatment like cell death, cell viability, or cell proliferation. The results indicate that different hypericin phototoxicity levels can be observed according to the specific light dose and concentration. Furthermore, it was shown that cellular localization and cell death mechanisms (apoptosis and necrosis) are dependent on the cell type.

Development of multifunctional nanocomposites for controlled drug delivery and hyperthermia

Magnetic nano/micro-particles based on clinoptilolite-type of natural zeolite (CZ) were fabricated and were expected to act as carriers for controlled drug delivery/release, imaging and local heating in biological systems. Adsorption of rhodamine B, sulfonated aluminum phthalocyanine and hypericin by magnetic CZ nano/micro-particles was investigated, as was the release of hypericin. Using an alternating magnetic field, local temperature increase by 10 °C in animal tissue with injected magnetic CZ particles was demonstrated. In addition, the CZ-based particles have been found to exhibit an anti-amyloidogenic effect on the amyloid aggregation of insulin and lysozyme in a dose- and temperature-dependent manner. Therefore, the mesoporous structure of CZ particles provided a unique platform for preparation of multifunctional magnetic and optical probes suitable for optical imaging, MRI, thermo- and phototherapy and as effective containers for controlled drug delivery. We concluded that magnetic CZ nano/micro-particles could be evaluated for further application in cancer hyperthermia therapy and as anti-amyloidogenic agents.

In vivo study of hypericin-loaded poloxamer-based mucoadhesive in situ gelling liquid crystalline precursor system in a mice model of vulvovaginal candidiasis

The present study reports the performance of the pigment hypericin (HYP)-loaded poloxamer-based mucoadhesive in situ gelling liquid crystalline precursor system (LCPS) for the treatment of vulvovaginal candidiasis (VVC) in mice. LCPS composed of 40% of ethoxylated and propoxylated cetyl alcohol, 30% of oleic acid and cholesterol (7:1), 30% of a dispersion of 16% poloxamer 407 and 0.05% of HYP (HYP-LCPS) was prepared and characterized by polarized light microscopy (PLM), small-angle X-ray scattering (SAXS) and ex vivo permeation and retention studies across vaginal porcine mucosa were performed. In addition, the antifungal properties of the HYP-LCPS were evaluated in a murine in vivo model; for this, infected C57BL female mice groups were treated with both HYP in solution and HYP-LCPS, and after 6 days colony forming unit (CFU)/ml count was performed. PLM and SAXS confirmed that HYP-LCPS is a microemulsion situated in boundary transition region confirming its action as an LCPS. When in contact with simulated vaginal fluid, HYP-LCPS became rigid and exhibited maltase crosses and bragg peaks characteristics of lamellar phase. Ex vivo permeation and retention studies showed that HYP-LCPS provides a localized treatment on the superficial layers of porcine vaginal mucosa. HYP-LCPS induced a significant reduction in the number of CFU/ml in the mice; thus this formulation indicated it is as effective as a commercial dosage form. It was concluded that LCPS maintains the biological activity of HYP and provides an adequate drug delivery system for this lipophilic molecule at the vaginal mucosa, being a promising option in cases of VVC.

A novel multimodal nanoplatform for targeting tumor necrosis

Peri-necrotic tumor regions have been found to be a source of cancer stem cells (CSC), important in tumor recurrence. Necrotic and peri-necrotic tumor zones have poor vascular supply, limiting effective exposure to systemically administered therapeutics. Therefore, there is a critical need to develop agents that can effectively target these relatively protected tumor areas. We have developed a multi-property nanoplatform with necrosis avidity, fluorescence imaging and X-ray tracking capabilities to evaluate its feasibility for therapeutic drug delivery. The developed nanoparticle consists of three elements: poly(ethylene glycol)-block-poly(ε-caprolactone) as the biodegradable carrier; hypericin as a natural compound with fluorescence and necrosis avidity; and gold nanoparticles for X-ray tracking. This reproducible nanoparticle has a hydrodynamic size of 103.9 ± 1.7 nm with a uniform spherical morphology (polydispersity index = 0.12). The nanoparticle shows safety with systemic administration and a stable 30 day profile. Intravenous nanoparticle injection into a subcutaneous tumor-bearing mouse and intra-arterial nanoparticle injection into rabbits bearing VX2 orthotopic liver tumors resulted in fluorescence and X-ray attenuation within the tumors. In addition, ex vivo and histological analysis confirmed the accumulation of hypericin and gold in areas of necrosis and peri-necrosis. This nanoplatform, therefore, has the potential to enhance putative therapeutic drug delivery to necrotic and peri-necrotic areas, and may also have an application for monitoring early response to anti-tumor therapies.

Au-Hyp-NP developed by encapsulation of gold and hypericin into PEG-PCL nanoplatform for fluorescence and X-ray tracking with tumor necrosis targeting.

Antiproliferative Effects of St. John's Wort, Its Derivatives, and Other Hypericum Species in Hematologic Malignancies

Hypericum is a widely present plant, and extracts of its leaves, flowers, and aerial elements have been employed for many years as therapeutic cures for depression, skin wounds, and respiratory and inflammatory disorders. Hypericum also displays an ample variety of other biological actions, such as hypotensive, analgesic, anti-infective, anti-oxidant, and spasmolytic abilities. However, recent investigations highlighted that this species could be advantageous for the cure of other pathological situations, such as trigeminal neuralgia, as well as in the treatment of cancer. This review focuses on the in vitro and in vivo antitumor effects of St. John’s Wort (Hypericum perforatum), its derivatives, and other Hypericum species in hematologic malignancies. Hypericum induces apoptosis in both myeloid and lymphoid cells. Other Hypericum targets include matrix metalloproteinase-2, vascular endothelial growth factor, and matrix metalloproteinase-9, which are mediators of cell migration and angiogenesis. Hypericum also downregulates the expression of proteins that are involved in the resistance of leukemia cells to chemotherapeutic agents. Finally, Hypericum and its derivatives appear to have photodynamic effects and are candidates for applications in tumor photodynamic therapy. Although the in vitro studies appear promising, controlled in vivo studies are necessary before we can hypothesize the introduction of Hypericum and its derivatives into clinical practice for the treatment of hematologic malignancies.

Hypericin-mediated photodynamic therapy for the treatment of cancer: a review

OBJECTIVES

Hypericin is a polycyclic aromatic naphthodianthrone that occurs naturally. It is also an active ingredient in some species of the genus Hypericum. Emerging evidence suggests that hypericin has attracted great attention as a potential anticancer drug and exhibits remarkable antiproliferative effect upon irradiation on various tumour cells. This paper aims to summarise the anticancer effect and molecular mechanisms modulated by hypericin-medicated photodynamic therapy and its potential role in the cancer treatment.

KEY FINDINGS

Hypericin-medicated photodynamic therapy could inhibit the proliferation of various tumour cells including bladder, colon, breast, cervical, glioma, leukaemia, hepatic, melanoma, lymphoma and lung cancers. The effect is primarily mediated by p38 mitogen-activated protein kinase (MAPK), JNK, PI3K, CCAAT-enhancer-binding protein homologous protein (CHOP)/TRIB3/Akt/mTOR, TRAIL/TRAIL-receptor, c-Met and Ephrin-Eph, the mitochondria and extrinsic signalling pathways. Furthermore, hypericin-medicated photodynamic therapy in conjunction with chemotherapeutic agents or targeted therapies is more effective in inhibiting the growth of tumour cells.

SUMMARY

During the past few decades, the anticancer properties of photoactivated hypericin have been extensively investigated. Hypericin-medicated photodynamic therapy can modulate a variety of proteins and genes and exhibit a great potential to be used as a therapeutic agent for various types of cancer.

A Review of Analytical Methods for the Determination of Hypericin in Foods, Herbal, Biological and Pharmaceutical Matrices

Aims:

A review of analytical methods for the determination of hypericin in foods, herbal, biological and pharmaceutical matrices.

Background:

Hypericin (HYP) is a naturally-occurring pigment obtained from some plants of the genus Hypericum. Although HYP has been known for many years, it has recently attracted attention due to its varied biological properties, such as anti-inflammatory and antidepressant activity and it is also an efficient photosensitizer.

Objective:

The objective of this review is to provide insights into the physicochemical properties of HYP, as well as to report the analytical methods existing in the literature and official compendia for different matrices.

Methods:

The survey data were collected by Google Scholar® and Scopus® using keys terms.

Result:

Analytical methods involving HYP are mainly concerned with the quality control of pharmaceutical preparations, foods, beverages, biological samples and drug delivery systems using different types of analysis methods. Some difficulties have also been identified due to the physicochemical properties of HYP. It presents great solubility in alkaline solutions, organic bases and common polar organic solvents.

Conclusion:

It can be analyzed by thin layer chromatography, spectrophotometry in the ultraviolet region, but the most commonly used method is by HPLC. HYP presents monographs in the American, British and European Pharmacopoeias, however, the methods of analysis are not yet harmonized.

Role of Photoactive Phytocompounds in Photodynamic Therapy of Cancer

Cancer is one of the greatest life-threatening diseases conventionally treated using chemo- and radio-therapy. Photodynamic therapy (PDT) is a promising approach to eradicate different types of cancers. PDT requires the administration of photosensitisers (PSs) and photoactivation using a specific wavelength of light in the presence of molecular oxygen. This photoactivation exerts an anticancer effect via apoptosis, necrosis, and autophagy of cancer cells. Recently, various natural compounds that exhibit photosensitising potentials have been identified. Photoactive substances derived from medicinal plants have been found to be safe in comparison with synthetic compounds. Many articles have focused on PDT mechanisms and types of PSs, but limited attention has been paid to the phototoxic activities of phytocompounds. The reduced toxicity and side effects of natural compounds inspire the researchers to identify and use plant extracts or phytocompounds as a potent natural PS candidate for PDT. This review focusses on the importance of common photoactive groups (furanocoumarins, polyacetylenes, thiophenes, curcumins, alkaloids, and anthraquinones), their phototoxic effects, anticancer activity and use as a potent PS for an effective PDT outcome in the treatment of various cancers.

The Influence of Hypericin-Mediated Photodynamic Therapy on Interleukin-8 and -10 Secretion in Colon Cancer Cells

The aim of this study was to measure the secretion of interleukin (IL)-8 and -10 during an elicited immune response following sublethal doses of hypericin-mediated photodynamic therapy (HY-PDT) in experimental models of residual colon cancer cells in vitro. Investigations were performed on the cancer cell lines SW480 and SW620. Each cell line was exposed to 3 different concentrations of the photosensitizer HY and various doses of irradiation. The cell metabolic activity using an MTT assay was performed and then the measurement of IL-8 and IL-10 secretion was achieved using the Bio-Plex ProTMAssay. There was a statistically significant amplification of IL-8 secretion during HY-PDT in the SW620 cell line (at 1 J/cm2: P = .01, 5 J/cm2: P = .002, and 10 J/cm2: P = .025) and a statistically significant decrease in IL-8 during HY-PDT in the SW480 cell line (at 1 J/cm2: P = .05, 5 J/cm2: P = .035, and 10 J/cm2: P = .035). No statistically significant differences in IL-10 concentration were found following HY-PDT in the SW480 (at 1 J/cm2: P > .4, 5 J/cm2: P = .1, and 10 J/cm2: P = .075) or in the SW620 cell line (at 1 J/cm2: P > .4, 5 J/cm2: P > .4, and 10 J/cm2: P > .4). HY-PDT can both eliminate and control a primary tumor via cytotoxic effects, and at sublethal doses, it can affect IL release by colon cancer cells. In this experiment, this influence depended on the level of tumor cell metastatic activity.

Hypericin photodynamic activity in DPPC liposomes - part II: stability and application in melanoma B16-F10 cancer cells

Hypericin (Hyp) is considered a promising photosensitizer for Photodynamic Therapy (PDT), due to its high hydrophobicity, affinity for cell membranes, low toxicity and high photooxidation activity. In this study, Hyp photophysical properties and photodynamic activity against melanoma B16-F10 cells were optimized using DPPC liposomes (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) as a drug delivery system. This nanoparticle is used as a cell membrane biomimetic model and solubilizes hydrophobic drugs. Hyp oxygen singlet lifetime (τ) in DPPC was approximately two-fold larger than that in P-123 micelles (Pluronic™ surfactants), reflecting a more hydrophobic environment provided by the DPPC liposome. On the other hand, singlet oxygen quantum yield values (Φ_Δ¹O₂) in DPPC and P-123 were similar; Hyp molecules were preserved as monomers. The Hyp/DPPC liposome aqueous dispersion was stable during fluorescence emission and the liposome diameter remained stable for at least five days at 30 °C. However, the liposomes collapsed after the lyophilization/rehydration process, which was resolved by adding the lyoprotectant Trehalose to the liposome dispersion before lyophilization. Cell viability of the Hyp/DPPC formulation was assessed against healthy HaCat cells and high-metastatic melanoma B16-F10 cells. Hyp incorporated into the DPPC carrier presented a higher selectivity index than the Hyp sample previously solubilized in ethanol under the illumination effect. Moreover, the IC₅₀ was lower for Hyp in DPPC than for Hyp pre-solubilized in ethanol. These results indicate the potential of the formulation of Hyp/DPPC for future biomedical applications in PDT treatment.

Nanoscale drug delivery strategies for therapy of ovarian cancer: conventional vs targeted

Ovarian cancer is the second most common gynaecological malignancy. It usually occurs in women older than 50 years, and because 75% of cases are diagnosed at stage III or IV it is associated with poor diagnosis. Despite the chemosensitivity of intraperitoneal chemotherapy, the majority of patients is relapsed and eventually dies. In addition to the challenge of early detection, its treatment presents several challenges like the route of administration, resistance to therapy with recurrence and specific targeting of cancer to reduce cytotoxicity and side effects. In ovarian cancer therapy, nanocarriers help overcome problems of poor aqueous solubility of chemotherapeutic drugs and enhance their delivery to the tumour sites either by passive or active targeting, and thus reducing adverse side effects to the healthy tissues. Moreover, the bioavailability to the tumour site is increased by the enhanced permeability and retention (EPR) mechanism. The present review aims to describe the current conventional treatment with special reference to passively and actively targeted drug delivery systems (DDSs) towards specific receptors designed against ovarian cancer to overcome the drawbacks of conventional delivery. Conclusively, targeted nanocarriers would optimise the intra-tumour distribution, followed by drug delivery into the intracellular compartment. These features may contribute to greater therapeutic effect.

Glyco-nanoparticles: New drug delivery systems in cancer therapy

Cancer is known as one of the most common diseases that are associated with high mobility and mortality in the world. Despite several efforts, current cancer treatment modalities often are highly toxic and lack efficacy and specificity. However, the application of nanotechnology has led to the development of effective nanosized drug delivery systems which are highly selective for tumors and allow a slow release of active anticancer agents. Different Nanoparticles (NPs) such as the silicon-based nano-materials, polymers, liposomes and metal NPs have been designed to deliver anti-cancer drugs to tumor sites. Among different drug delivery systems, carbohydrate-functionalized nanomaterials, specially based on their multi-valent binding capacities and desirable bio-compatibility, have attracted considerable attention as an excellent candidate for controlled release of therapeutic agents. In addition, these carbohydrate functionalized nano-carriers are more compatible with construction of the intracellular delivery platforms like the carbohydrate-modified metal NPs, quantum dots, and magnetic nano-materials. In this review, we discuss recent research in the field of multifunctional glycol-nanoparticles (GNPs) intended for cancer drug delivery applications.

The Dark Side: Photosensitizer Prodrugs

Photodynamic therapy (PDT) and photodiagnosis (PD) are essential approaches in the field of biophotonics. Ideally, both modalities require the selective sensitization of the targeted disease in order to avoid undesired phenomena such as the destruction of healthy tissue, skin photosensitization, or mistaken diagnosis. To a large extent, the occurrence of these incidents can be attributed to “background” accumulation in non-target tissue. Therefore, an ideal photoactive compound should be optically silent in the absence of disease, but bright in its presence. Such requirements can be fulfilled using innovative prodrug strategies targeting disease-associated alterations. Here we will summarize the elaboration, characterization, and evaluation of approaches using polymeric photosensitizer prodrugs, nanoparticles, micelles, and porphysomes. Finally, we will discuss the use of 5-aminolevulinc acid and its derivatives that are selectively transformed in neoplastic cells into photoactive protoporphyrin IX.

Enhancing Breast Cancer Treatment Using a Combination of Cannabidiol and Gold Nanoparticles for Photodynamic Therapy

Indisputably, cancer is a global crisis that requires immediate intervention. Despite the use of conventional treatments over the past decades, it is acceptable to admit that these are expensive, invasive, associated with many side effects and, therefore, a reduced quality of life. One of the most possible solutions to this could be the use of gold nanoparticle (AuNP) conjugated photodynamic therapy (PDT) in combination with cannabidiol (CBD), a Cannabis derivative from the Cannabis sativa. Since the use of Cannabis has always been associated with recreation and psychoactive qualities, the positive effects of Cannabis or its derivatives on cancer treatment have been misunderstood and hence misinterpreted. On the other hand, AuNP-PDT is the most favoured form of treatment for cancer, due to its augmented specificity and minimal risk of side effects compared to conventional treatments. However, its use requires the consideration of several physical, biologic, pharmacologic and immunological factors, which may hinder its effectiveness if not taken into consideration. In this review, the role of gold nanoparticle mediated PDT combined with CBD treatment on breast cancer cells will be deliberated.

Copolymeric micelles as efficient inert nanocarrier for hypericin in the photodynamic inactivation of Candida species

Aim: To evaluate the efficacy of photodynamic inactivation (PDI) mediated by hypericin encapsulated in P-123 copolymeric micelles (P123-Hyp) alone and in combination with fluconazole (FLU) against planktonic cells and biofilm formation of Candida species Materials & methods: PDI was performed using P123-Hyp and an LED device with irradiance of 3.0 mW/cm2 . Results: Most of isolates (70%) were completely inhibited with concentrations up to 2.0 μmol/l of HYP and light fluence of 16.2 J/cm2. FLU-resistant strains had synergic effect with P123-HYP-PDI and FLU. The biofilm formation was inhibited in all species, in additional the changes in Candida morphology observed by scanning electron microscopy. Conclusion: P123-Hyp-PDI is a promising option to treat fungal infections and medical devices to prevent biofilm formation and fungal spread.

Biosynthesis of Silver Nanoparticles Using Ligustrum Ovalifolium Fruits and Their Cytotoxic Effects

The present study reports for the first time the efficacy of bioactive compounds from Ligustrum ovalifolium L. fruit extract as reducing and capping agents of silver nanoparticles (AgNPs), developing a green, zero energetic, cost effective and simple synthesis method of AgNPs. The obtained nanoparticles were characterized by UV-Vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR), confirming that nanoparticles were crystalline in nature, spherical in shape, with an average size of 7 nm. The FTIR spectroscopy analysis demonstrated that the AgNPs were capped and stabilized by bioactive molecules from the fruit extract. The cytotoxicity of the biosynthesized AgNPs was in vitro evaluated against ovarian carcinoma cells and there were found to be effective at low concentration levels.

Hypericin-assisted photodynamic therapy against anaplastic thyroid cancer

BACKGROUND

Hypericin (HYP) extracted from St. John's wort (Hypericum perforatum L.) is a natural photosensitizer in clinical photodynamic therapy (PDT). PDT is one of the powerful methods for cancer treatments because of its excellent tumoritropic characteristics and photosensitizing properties. However, limited reports on the efficacy of PDT on anaplastic thyroid cancer (ATC) have been published. Especially HYP-associated PDT has not been investigated in vitro and in vivo. In this study, we evaluated the effect of HYP for PDT against FRO ATC cells.

METHODS

The activities of HYP-assisted PDT were investigated in ATC cells. The ATC FRO cells were treated with a combination of HYP dose and laser power. The viability of FRO cells was measured by MTT assay, and Trypan blue staining was performed to monitor cell death. Detection reactive oxygen species (ROS) and mitochondrial membrane potential after HYP-assisted PDT were analyzed by confocal microscopy. For in vivo study, FRO cells were injected into nude mice. After intravenous injection of HYP, Laser was irradiated and nude mice were monitored in Day 4, 7, 14.

RESULTS AND CONCLUSIONS

The rate of FRO cell death was increased by applying HYP dose and laser power dependent. Moreover, HYP and laser irradiation induced FRO cell death was mediated by the intracellular ROS generation and mitochondrial damage. Finally, the HYP-assisted PDT eliminated FRO cell tumor from the mouse in vivo. These data demonstrate that HYP could be an effective photosensitizer for human ATC therapy.

Facile fabrication of hypericin-entrapped glyconanoparticles for targeted photodynamic therapy

BACKGROUND

Photodynamic therapy is a safe, noninvasive modality for cancer therapy, in which the photosensitizer (PS) is a crucial component. Hypericin (Hy) is a promising PS; however, its clinical application is significantly limited by its poor hydrophilicity.

MATERIALS AND METHODS

To overcome the clinical application limitation of Hy, a novel strategy is developed here by entrapping Hy into polydopamine (PDA) film formed on the surface of magnetic iron oxide nanoparticles (MNPs) through the self-polymerization of dopamine under alkaline condition. The amount of Hy in the Hy-entrapped PDA-MNP composite nanoparticles (denoted as PHMs) was measured by spectrophotometry. Furthermore, lactose, as the targeting ligand to asialoglycoprotein receptors, was conjugated to the surface of the PHMs by taking advantage of the spontaneous reaction of PDA with amino groups.

RESULTS

Spectrophotometry analysis revealed that the amount of Hy in the PHMs was 72 μmol g-1 PHMs. The fabricated Hy-entrapped glyconanoparticle (Lac-PHM) exhibited excellent water dispersibility, stability, and selectivity for asialoglycoprotein receptors overexpressing HepG2 cells. Atomic absorption spectroscopy analysis showed that the amount of the Lac-PHMs taken in HepG2 cells was 2.1-fold higher than that of the triethylene glycol-modified PHMs. The results of intracellular reactive oxygen species generation detection, cytotoxicity study, and apoptosis detection indicated that the Lac-PHMs had a satisfying photodynamic effect to HepG2 cells.

CONCLUSION

The strategy developed in this work offers great potential for delivery of a variety of hydrophobic PSs.

Photodynamic therapy - mechanisms, photosensitizers and combinations

Photodynamic therapy (PDT) is a modern and non-invasive form of therapy, used in the treatment of non-oncological diseases as well as cancers of various types and locations. It is based on the local or systemic application of a photosensitive compound - the photosensitizer, which is accumulated in pathological tissues. The photosensitizer molecules absorb the light of the appropriate wavelength, initiating the activation processes leading to the selective destruction of the inappropriate cells. The photocytotoxic reactions occur only within the pathological tissues, in the area of photosensitizer distribution, enabling selective destruction. Over the last decade, a significant acceleration in the development of nanotechnology has been observed. The combination of photosensitizers with nanomaterials can improve the photodynamic therapy efficiency and eliminate its side effects as well. The use of nanoparticles enables achievement a targeted method which is focused on specific receptors, and, as a result, increases the selectivity of the photodynamic therapy. The object of this review is the anticancer application of PDT, its advantages and possible modifications to potentiate its effects.

Nanotechnology for Cancer Therapy Based on Chemotherapy

Chemotherapy has been widely applied in clinics. However, the therapeutic potential of chemotherapy against cancer is seriously dissatisfactory due to the nonspecific drug distribution, multidrug resistance (MDR) and the heterogeneity of cancer. Therefore, combinational therapy based on chemotherapy mediated by nanotechnology, has been the trend in clinical research at present, which can result in a remarkably increased therapeutic efficiency with few side effects to normal tissues. Moreover, to achieve the accurate pre-diagnosis and real-time monitoring for tumor, the research of nano-theranostics, which integrates diagnosis with treatment process, is a promising field in cancer treatment. In this review, the recent studies on combinational therapy based on chemotherapy will be systematically discussed. Furthermore, as a current trend in cancer treatment, advance in theranostic nanoparticles based on chemotherapy will be exemplified briefly. Finally, the present challenges and improvement tips will be presented in combination therapy and nano-theranostics.

Photodynamic Therapy

Photodynamic therapy is a clinical technique for the treatment of cancers, microbial infections and other medical conditions by means of light-induced generation of reactive oxygen species using photosensitising drugs. The intrinsic fluorescence of many such drugs make them potential theranostic agents for simultaneous diagnosis and therapy. This chapter reviews the basic chemical and biological aspects of photodynamic therapy with an emphasis on its applications in theranostics. The roles of nanotechnology is highlighted, as well as emerging trends such as photoimmunotherapy, image-guided surgery and light- and singlet-oxygen dosimetry.

Polymer-based nanoparticles loaded with a TLR7 ligand to target the lymph node for immunostimulation

Small-molecule agonists for the Toll-like receptors (TLR) 7 and 8 are effective for the immunotherapy of skin cancer when used as topical agents. Their systemic use has however been largely unsuccessful due to dose-limiting toxicity. We propose a polymer-based nanodelivery system to target resiquimod, a TLR7 ligand, to the lymph node in order to focus the immunostimulatory activity and to prevent a generalized inflammatory response. We demonstrate successful encapsulation of resiquimod in methoxypoly(ethylene glycol)-b-poly(DL-lactic acid) (mPEG-PLA) and mixed poly(DL-lactic-co-glycolic acid) (PLGA)/mPEG-PLA nanoparticles. We show that these particles are taken up mainly by dendritic cells and macrophages, which are the prime initiators of anticancer immune responses. Nanoparticles loaded with resiquimod activate these cells, demonstrating the availability of the immune-stimulating cargo. The unloaded particles are non-inflammatory and do not have cytotoxic activity on immune cells. Following subcutaneous injection in mice, mPEG-PLA and PLGA/mPEG-PLA nanoparticles are detected in dendritic cells and macrophages in the draining lymph nodes, demonstrating the targeting potential of these particles. Thus, polymer-based nanoparticles represent a promising delivery system that allows lymph node targeting for small-molecule TLR7 agonists in the context of systemic cancer immunotherapy.

Investigating the effect of poly-l-lactic acid nanoparticles carrying hypericin on the flow-biased diffusive motion of HeLa cell organelles

OBJECTIVES

In this study, we investigate in human cervical epithelial HeLa cells the intracellular dynamics and the mutual interaction with the organelles of the poly-l-lactic acid nanoparticles (PLLA NPs) carrying the naturally occurring hydrophobic photosensitizer hypericin.

METHODS

Temporal and spatiotemporal image correlation spectroscopy was used for the assessment of the intracellular diffusion and directed motion of the nanocarriers by tracking the hypericin fluorescence. Using image cross-correlation spectroscopy and specific fluorescent labelling of endosomes, lysosomes and mitochondria, the NPs dynamics in association with the cell organelles was studied. Static colocalization experiments were interpreted according to the Manders' overlap coefficient.

KEY FINDINGS

Nanoparticles associate with a small fraction of the whole-organelle population. The organelles moving with NPs exhibit higher directed motion compared to those moving without them. The rate of the directed motion drops substantially after the application of nocodazole. The random component of the organelle motions is not influenced by the NPs.

CONCLUSIONS

Image correlation and cross-correlation spectroscopy are most appropriate to unravel the motion of the PLLA nanocarrier and to demonstrate that the rate of the directed motion of organelles is influenced by their interaction with the nanocarriers. Not all PLLA-hypericin NPs are associated with organelles.

Hypocrellin B and nano silver loaded polymeric nanoparticles: Enhanced generation of singlet oxygen for improved photodynamic therapy

A nanoparticulate photodynamic approach was employed with an objective to achieve enhanced production of singlet oxygen (¹O₂), for the management of posterior segment eye diseases like age related macular degeneration. The hypocrellin B (HB) loaded poly lactide-co-glycolide nanoparticle formulations were incorporated with nano silver (HBS-NPs). The optimized HBS-NPs contained 2.60±0.06mg/mL of HB and showed (i) 135.6 to 828.2nm size range, and (ii) negative zeta potential with a narrow polydispersity index. The DSC thermograms suggested the amorphous nature of HB inside the HBS-NPs. With the average encapsulation efficiency of 92.9±1.79%, the drug release from the HBS-NPs followed a biphasic pattern with an initial burst of 3.50% during first 8h followed by a sustained release of 47.82% within 3days. The interaction between nano silver and HB as assessed by the increase in spectral intensity of Raman spectrum demonstrates that HB may be attached over the nano silver. Generation of reactive oxygen species (ROS) by HBS-NPs was significantly higher than that of HB/HB-NPs. The singlet oxygen generating efficiency assessed using EPR spectrometer follows the order of nano silver>HB-NPs>pure HB drug solution>HBS-NPs. The HBS-NPs had a concentration and time dependent phototoxicity on A549 (human adeno lung carcinoma) cells in the presence of light providing a superior phototoxic effect (82.2% at 50μM) at 2h irradiation. The CAM treated with HBS-NPs showed a significant anti-angiogenic effect compared to a blank formulation. In vivo biodistribution studies revealed that intravenous administration of HBS-NPs lead into significant exposure to the posterior segment of the eye. This proof of principle study demonstrates that HB based nanoparticles may be a valuable new tool for application in ocular photodynamic therapy for the treatment of AMD in future.

Tuning the local solvent composition at a drug carrier surface: the effect of dimethyl sulfoxide/water mixture on the photofunctional properties of hypericin-β-lactoglobulin complexes

Aggregation is a major problem for the anti-microbial photodynamic applications of hydrophobic photosensitizers since it strongly reduces the amount of singlet oxygen generated in aqueous solutions. Binding of hypericin (Hyp) to the milk whey protein β-lactoglobulin (βLG), occurring at the two hydrophobic cavities located at the interface of the protein homodimer, can be exploited to confer water-solubility and biocompatibility to the photosensitizer. The introduction of a small amount of the organic cosolvent dimethyl sulfoxide (DMSO) leads to a remarkable improvement of the photophysical properties of the complex Hyp-βLG by increasing its fluorescence emission and singlet oxygen photosensitization quantum yields. Surprisingly, the ability of the complex to photo-inactivate bacteria of the strain Staphylococcus aureus is strongly reduced in the presence of DMSO, despite the higher yield of photosensitization. The reasons for this apparently contradictory behavior are investigated, providing new insights into the use of carrier systems for hydrophobic photosensitizers.

Size-engineered biocompatible polymeric nanophotosensitizer for locoregional photodynamic therapy of cancer

Current approaches in use of water-insoluble photosensitizers for photodynamic therapy (PDT) of cancer often demand a nano-delivery system. Here, we report a photosensitizer-loaded biocompatible nano-delivery formulation (PPaN-20) whose size was engineered to ca. 20nm to offer improved cell/tissue penetration and efficient generation of cytotoxic singlet oxygen. PPaN-20 was fabricated through the physical assembly of all biocompatible constituents: pyropheophorbide-a (PPa, water-insoluble photosensitizer), polycaprolactone (PCL, hydrophobic/biodegradable polymer), and Pluronic F-68 (clinically approved polymeric surfactant). Repeated microemulsification/evaporation method resulted in a fine colloidal dispersion of PPaN-20 in water, where the particulate PCL matrix containing well-dispersed PPa molecules inside was stabilized by the Pluronic corona. Compared to a control sample of large-sized nanoparticles (PPaN-200) prepared by a conventional solvent displacement method, PPaN-20 revealed optimal singlet oxygen generation and efficient cellular uptake by virtue of the suitably engineered size and constitution, leading to high in vitro phototoxicity against cancer cells. Upon administration to tumor-bearing mice by peritumoral route, PPaN-20 showed efficient tumor accumulation by the enhanced cell/tissue penetration evidenced by in vivo near-infrared fluorescence imaging. The in vivo PDT treatment with peritumorally administrated PPaN-20 showed significantly enhanced suppression of tumor growth compared to the control group, demonstrating great potential as a biocompatible photosensitizing agent for locoregional PDT treatment of cancer.

A Comparative Study of Cellular Uptake and Subcellular Localization of Doxorubicin Loaded in Self-Assemblies of Amphiphilic Copolymers with Pendant Dendron by MDA-MB-231 Human Breast Cancer Cells

Previously synthesized amphiphilic diblock copolymers with pendant dendron moieties have been investigated for their potential use as drug carriers to improve the delivery of an anticancer drug to human breast cancer cells. Diblock copolymer (P71 D3 )-based micelles effectively encapsulate the doxorubicin (DOX) with a high drug-loading capacity (≈95%, 104 DOX molecules per micelle), which is approximately double the amount of drug loaded into the diblock copolymer (P296 D1 ) vesicles. DOX released from the resultant P71 D3 /DOX micelles is approximately 1.3-fold more abundant, at a tumoral acidic pH of 5.5 compared with a pH of 7.4. The P71 D3 /DOX micelles also enhance drug potency in breast cancer MDA-MB-231 cells due to their higher intracellular uptake, by approximately twofold, compared with the vesicular nanocarrier, and free DOX. Micellar nanocarriers are taken up by lysosomes via energy-dependent processes, followed by the release of DOX into the cytoplasm and subsequent translocation into the nucleus, where it exert its cytotoxic effect.

Development and characterization of bio-derived polyhydroxyalkanoate nanoparticles as a delivery system for hydrophobic photodynamic therapy agents

In this study, we developed and investigated nanoparticles of biologically-derived, biodegradable polyhydroxyalkanoates (PHAs) as carriers of a hydrophobic photosensitizer, 5,10,15,20-Tetrakis(4-hydroxy-phenyl)-21H, 23H-porphine (pTHPP) for photodynamic therapy (PDT). Three PHA variants; polyhydroxybutyrate, poly(hydroxybutyrate-co-hydroxyvalerate) or P(HB-HV) with 12 and 50% HV were used to formulate pTHPP-loaded PHA nanoparticles by an emulsification-diffusion method, where we compared two different poly(vinyl alcohol) (PVA) stabilizers. The nanoparticles exhibited nano-scale spherical morphology under TEM and hydrodynamic diameters ranging from 169.0 to 211.2 nm with narrow size distribution. The amount of drug loaded and the drug entrapment efficiency were also investigated. The in vitro photocytotoxicity was evaluated using human colon adenocarcinoma cell line HT-29 and revealed time and concentration dependent cell death, consistent with a gradual release pattern of pTHPP over 24 h. This study is the first demonstration using bacterially derived P(HB-HV) copolymers for nanoparticle delivery of a hydrophobic photosensitizer drug and their potential application in PDT.