Development of inhalable curcumin loaded Nano-in-Microparticles for bronchoscopic photodynamic therapy

Natural Products-Based Inhaled Formulations for Treating Pulmonary Diseases

Given the unique physiological and pathological characteristics of the lung, the direct, inhalable route is more conducive to pulmonary drug delivery and disease control than traditional systemic drug delivery, significantly circumventing drug loss, off-target effects, systemic and organ toxicity, etc., and is widely regarded as the preferred regimen for pulmonary drug delivery. However, very few lung diseases are currently treated with the preferred inhaled formulations, such as asthma, chronic obstructive pulmonary disease and pulmonary hypertension. And there is a lack of appropriate inhaled formulations for other critical lung diseases, such as lung cancer and pulmonary fibrosis, due to the fact that the physicochemical properties of the drugs and their pharmacokinetic profiles do not match the physiology of the lung, and conventional inhalation devices are unable to deliver them to the specific parts of the lung. Phytochemicals of natural origin, due to their wide availability and clear safety profile, hold great promise for the preparation of inhalable formulations to improve the current dilemma in the treatment of lung diseases. In particular, the preparation of inhalable formulations based on nano- and microparticulate carriers for drug delivery to deep lung tissues, which overcome the shortcomings of conventional inhalation therapies while targeting the drug activity directly to a specific part of the lung, may be the best approach to change the current dilemma of lung disease treatment. In this review, we discuss recent advances in nano- and micron-carrier-based inhalation formulations for the delivery of natural products for the treatment of pulmonary diseases, which may represent an opportunity for practical clinical translation of natural products.

Dual Action of Curcumin as an Anti- and Pro-Oxidant from a Biophysical Perspective

Curcumin, a natural polyphenol widely used as a spice, colorant and food additive, has been shown to have therapeutic effects against different disorders, mostly due to its anti-oxidant properties. Curcumin also reduces the efficiency of melanin synthesis and affects cell membranes. However, curcumin can act as a pro-oxidant when blue light is applied, since upon illumination it can generate singlet oxygen. Our review aims to describe this dual role of curcumin from a biophysical perspective, bearing in mind its concentration, bioavailability-enhancing modifications and membrane interactions, as well as environmental conditions such as light. In low concentrations and without irradiation, curcumin shows positive effects and can be recommended as a beneficial food supplement. On the other hand, when used in excess or irradiated, curcumin can be toxic. Therefore, numerous attempts have been undertaken to test curcumin as a potential photosensitizer in photodynamic therapy (PDT). At that point, we underline that curcumin-based PDT is limited to the treatment of superficial tumors or skin and oral infections due to the weak penetration of blue light. Additionally, we conclude that an increase in curcumin bioavailability through the using nanocarriers, and therefore its concentration, as well as its topical use if skin is exposed to light, may be dangerous.

Multifunctional systems based on nano-in-microparticles as strategies for drug delivery: advances, challenges, and future perspectives

INTRODUCTION

Innovative delivery systems are a promising and attractive approach for drug targeting in pharmaceutical technology. Among the various drug delivery systems studied, the association of strategies based on nanoparticles and microparticles, called nano-in-microparticles, has been gaining prominence as it allows targeting in a specific and personalized way, considering the physiological barriers faced in each disease.

AREAS COVERED

This review proposes to discuss nano-in-micro systems, updated progress on the main biomaterials used in the preparation of these systems, preparation techniques, physiological considerations, applications and challenges, and possible strategies for drug administration. Finally, we bring future perspectives for advances in clinical and field translation of multifunctional systems based on nano-in-microparticles.

EXPERT OPINION

This article brings a new approach to exploring the use of multifunctional systems based on nano-in-microparticles for different applications, in addition, it also emphasizes the use of biomaterials in these systems and their limitations. There is currently no study in the literature that explores this approach, making a review article necessary to address this association of strategies for application in pharmaceutical technology.

Curcumin a Natural Phenol and Its Therapeutic Role in Cancer and Photodynamic Therapy: A Review

Cancer continues to cause an alarming number of deaths globally, and its burden on the health system is significant. Though different conventional therapeutic procedures are exploited for cancer treatment, the prevalence and death rates remain elevated. These, therefore, insinuate that novel and more efficient treatment procedures are needed for cancer. Curcumin, a bioactive, natural, phenolic compound isolated from the rhizome of the herbaceous plant turmeric, is receiving great interest for its exciting and broad pharmacological properties. Curcumin presents anticancer therapeutic capacities and can be utilized as a photosensitizing drug in cancer photodynamic therapy (PDT). Nonetheless, curcumin's poor bioavailability and related pharmacokinetics limit its clinical utility in cancer treatment. This review looks at the physical and chemical properties, bioavailability, and safety of curcumin, while focusing on curcumin as an agent in cancer therapy and as a photosensitizer in cancer PDT. The possible mechanisms and cellular targets of curcumin in cancer therapy and PDT are highlighted. Furthermore, recent improvements in curcumin's bioavailability in cancer therapy using nanoformulations and delivery systems are presented.

Inhalable microparticles as drug delivery systems to the lungs in a dry powder formulations

Inhalation-administrated drugs remain an interesting possibility of addressing pulmonary diseases. Direct drug delivery to the lungs allows one to obtain high concentration in the site of action with limited systemic distribution, leading to a more effective therapy with reduced required doses and side effects. On the other hand, there are several difficulties in obtaining a formulation that would meet all the criteria related to physicochemical, aerodynamic and biological properties, which is the reason why only very few of the investigated systems can reach the clinical trial phase and proceed to everyday use as a result. Therefore, we focused on powders consisting of polysaccharides, lipids, proteins or natural and synthetic polymers in the form of microparticles that are delivered by inhalation to the lungs as drug carriers. We summarized the most common trends in research today to provide the best dry powders in the right fraction for inhalation that would be able to release the drug before being removed by natural mechanisms. This review article addresses the most common manufacturing methods with novel modifications, pros and cons of different materials, drug loading capacities with release profiles, and biological properties such as cytocompatibility, bactericidal or anticancer properties.

Effect of Silica Microparticles on Interactions in Mono- and Multicomponent Membranes

Advancing our understanding of the mechanism of the interaction between inhaled pollutant microparticles and cell membrane components is useful to study the impact of fine particulate matter on human health. In this paper, we focus on the effect of cholesterol (Chol) molecules on the surface properties of a model membrane in the presence of silica microparticles (MPs). Mixed monolayers containing phospholipid-dipalmitoylphosphatidylcholine (DPPC), Chol and silica particle dispersions (MPs; 0.033% w/w, 0.33% w/w and 0.83% w/w) were formed and studied using the Langmuir monolayer technique complemented by Brewster Angle Microscopy (BAM) images. It was shown that Chol caused a condensation of the DPPC monolayer, which influenced the penetration of MPs and their interactions with the model membrane. The relaxation experiments of the lipid–MP monolayer proved that the presence of Chol molecules in the monolayer led to the formation of lipid and MP complexes. Strong interactions between Chol and MPs contributed to the formation of more stable monolayers. The presented results can be useful to better comprehend the interaction between particulate materials and the lipid components of biomembranes.

Lung surfactant negatively affects the photodynamic inactivation of bacteria-in vitro and molecular dynamic simulation analyses

In the context of the rapid increase of antibiotic-resistant infections, in particular of pneumonia, antimicrobial photodynamic therapy (aPDT), the microbiological application of photodynamic therapy (PDT), comes in as a promising treatment alternative since the induced damage and resultant death are not dependent on a specific biomolecule or cellular pathway. The applicability of aPDT using the photosensitizer indocyanine green with infrared light has been successfully demonstrated for different bacterial agents in vitro, and the combination of pulmonary delivery using nebulization and external light activation has been shown to be feasible. However, there has been little progress in obtaining sufficient in vivo efficacy results. This study reports the lung surfactant as a significant suppressor of aPDT in the lungs. In vitro, the clinical surfactant Survanta® reduced the aPDT effect of indocyanine green, Photodithazine®, bacteriochlorin-trizma, and protoporphyrin IX against Streptococcus pneumoniae. The absorbance and fluorescence spectra, as well as the photobleaching profile, suggested that the decrease in efficacy is not a result of singlet oxygen quenching, while a molecular dynamics simulation showed an affinity for the polar head groups of the surfactant phospholipids that likely impacts uptake of the photosensitizers by the bacteria. Methylene blue is the exception, likely because its high water solubility confers a higher mobility when interacting with the surfactant layer. We propose that the interaction between lung surfactant and photosensitizer must be taken into account when developing pulmonary aPDT protocols.

To Enhance Mucus Penetration and Lung Absorption of Drug by Inhalable Nanocrystals-In-Microparticles

To effectively achieve the pulmonary delivery for curcumin (CN), novel inhalable mucus-penetrating nanocrystal-based microparticles (INMP) were designed. The D-Tocopherol acid polyethylene glycol 1000 succinate (TPGS) modified CN nanocrystals (CN-NS@TPGS) were prepared by high pressure homogenization and further converted into nanocrystal-based microparticles (CN-INMP@TPGS) using spray-drying. It was demonstrated that CN-NS@TPGS exhibited little interaction with the negatively charged mucin due to a strong electrostatic repulsion effect and PEG hydrophilic chain, and exhibited a much higher penetration ability across the mucus layer compared with poloxamer 407 modified CN-NS (CN-NS@P407) and tween 80 modified CN-NS (CN-NS@TW80). The aerodynamic results demonstrated that the CN-INMP with 10% TPGS acting as the stabilizer presented a high FPF value, indicating excellent deposition in the lung after inhalation administration. Additionally, in vivo bioavailability studies indicated that the AUC(0-t) of CN-INMP@TPGS (2413.18 ± 432.41 µg/L h) were 1.497- and 3.32-fold larger compared with those of CN-INMP@TW80 (1612.35 ± 261.35 µg/L h) and CN-INMP@P407 (3.103 ± 196.81 µg/L h), respectively. These results indicated that the CN-INMP@TPGS were absorbed rapidly after pulmonary administration and resulted in increased systemic absorption. Therefore, the inhalable CN-INMP could significantly improve the bioavailability of CN after inhalation administration. The developed mucus-penetrating nanocrystals-in-microparticles might be regarded as a promising formulation strategy for the pulmonary administration of poorly soluble drugs.

Can Nanoparticles in Homeopathic Remedies Enhance Phototherapy of Cancer? A Hypothetical Model

The continuous rise in cancer incidence places a massive burden on the health sector to increase efforts in the fight against cancer. As a holistic complementary medicine modality, homeopathy has the potential to assist in the supportive and palliative treatment of cancer patients. Recent empirical studies demonstrate the presence of silica and original source nanoparticles in ultra-high dilutions of several homeopathic medicines. Recent studies have also demonstrated the efficacy of phototherapy in inducing the ablation of cancer cells through laser-activated nanoparticle photosensitizers. A new hypothetical research model is presented herein, in an attempt to investigate and compare the phototherapeutic effects of homeopathic source nanoparticles with photosensitizing nanoparticle agents that have previously been tested.

Latest Innovations and Nanotechnologies with Curcumin as a Nature-Inspired Photosensitizer Applied in the Photodynamic Therapy of Cancer

In the context of the high incidence of cancer worldwide, state-of-the-art photodynamic therapy (PDT) has entered as a usual protocol of attempting to eradicate cancer as a minimally invasive procedure, along with pharmacological resources and radiation therapy. The photosensitizer (PS) excited at certain wavelengths of the applied light source, in the presence of oxygen releases several free radicals and various oxidation products with high cytotoxic potential, which will lead to cell death in irradiated cancerous tissues. Current research focuses on the potential of natural products as a superior generation of photosensitizers, which through the latest nanotechnologies target tumors better, are less toxic to neighboring tissues, but at the same time, have improved light absorption for the more aggressive and widespread forms of cancer. Curcumin incorporated into nanotechnologies has a higher intracellular absorption, a higher targeting rate, increased toxicity to tumor cells, accelerates the activity of caspases and DNA cleavage, decreases the mitochondrial activity of cancer cells, decreases their viability and proliferation, decreases angiogenesis, and finally induces apoptosis. It reduces the size of the primary tumor, reverses multidrug resistance in chemotherapy and decreases resistance to radiation therapy in neoplasms. Current research has shown that the use of PDT and nanoformulations of curcumin has a modulating effect on ROS generation, so light or laser irradiation will lead to excessive ROS growth, while nanocurcumin will reduce the activation of ROS-producing enzymes or will determine the quick removal of ROS, seemingly opposite but synergistic phenomena by inducing neoplasm apoptosis, but at the same time, accelerating the repair of nearby tissue. The latest curcumin nanoformulations have a huge potential to optimize PDT, to overcome major side effects, resistance to chemotherapy, relapses and metastases. All the studies reviewed and presented revealed great potential for the applicability of nanoformulations of curcumin and PDT in cancer therapy.

Use of nanosystems to improve the anticancer effects of curcumin

Curcumin (CUR) is a phenolic compound that is safe for human consumption. It exhibits chemopreventive, antiproliferative, antiangiogenic, and antimetastatic effects. However, these benefits can be hampered due to the lipophilic nature, rapid metabolism, low bioavailability, and fast elimination of the molecule. Considering this, the present work reviews the use of CUR-based nanosystems as anticancer agents, including conventional nanosystems (i.e., liposomes, nanoemulsions, nanocrystals, nanosuspensions, polymeric nanoparticles) and nanosystems that respond to external stimuli (i.e., magnetic nanoparticles and photodynamic therapy). Previous studies showed that the effects of CUR were improved when loaded into nanosystems as compared to the free compound, as well as synergist effects when it is co-administrated alongside with other molecules. In order to maximize the beneficial health effects of CUR, critical factors need to be strictly controlled, such as particle size, morphology, and interaction between the encapsulating material and CUR. In addition, there is an area of study to be explored in the development of CUR-based smart materials for nanomedical applications. Imaging-guided drug delivery of CUR-based nanosystems may also directly target specific cells, thereby increasing the therapeutic and chemopreventive efficacy of this versatile compound.

Membrane-disruptive peptides/peptidomimetics-based therapeutics: Promising systems to combat bacteria and cancer in the drug-resistant era

Membrane-disruptive peptides/peptidomimetics (MDPs) are antimicrobials or anticarcinogens that present a general killing mechanism through the physical disruption of cell membranes, in contrast to conventional chemotherapeutic drugs, which act on precise targets such as DNA or specific enzymes. Owing to their rapid action, broad-spectrum activity, and mechanisms of action that potentially hinder the development of resistance, MDPs have been increasingly considered as future therapeutics in the drug-resistant era. Recently, growing experimental evidence has demonstrated that MDPs can also be utilized as adjuvants to enhance the therapeutic effects of other agents. In this review, we evaluate the literature around the broad-spectrum antimicrobial properties and anticancer activity of MDPs, and summarize the current development and mechanisms of MDPs alone or in combination with other agents. Notably, this review highlights recent advances in the design of various MDP-based drug delivery systems that can improve the therapeutic effect of MDPs, minimize side effects, and promote the co-delivery of multiple chemotherapeutics, for more efficient antimicrobial and anticancer therapy.

Improvement of Pulmonary Photodynamic Therapy: Nebulisation of Curcumin-Loaded Tetraether Liposomes

Lung cancer is one of the most common causes for a high number of cancer related mortalities worldwide. Therefore, it is important to improve the therapy by finding new targets and developing convenient therapies. One of these novel non-invasive strategies is the combination of pulmonary delivered tetraether liposomes and photodynamic therapy. In this study, liposomal model formulations containing the photosensitiser curcumin were nebulised via two different technologies, vibrating-mesh nebulisation and air-jet nebulisation, and compared with each other. Particle size and ζ-potential of the liposomes were investigated using dynamic light scattering and laser Doppler anemometry, respectively. Furthermore, atomic force microscopy and transmission electron microscopy were used to determine the morphological characteristics. Using a twin glass impinger, suitable aerodynamic properties were observed, with the fine particle fraction of the aerosols being ≤62.7 ± 1.6%. In vitro irradiation experiments on lung carcinoma cells (A549) revealed an excellent cytotoxic response of the nebulised liposomes in which the stabilisation of the lipid bilayer was the determining factor. Internalisation of nebulised curcumin-loaded liposomes was visualised utilising confocal laser scanning microscopy. Based on these results, the pulmonary application of curcumin-loaded tetraether liposomes can be considered as a promising approach for the photodynamic therapy against lung cancer.

Exploring the Role of Phytochemicals as Potent Natural Photosensitizers in Photodynamic Therapy

BACKGROUND

Cancer is still considered a deadly disease worldwide due to difficulties in diagnosis, painful treatment procedures, costly therapies, side effects, and cancer relapse. Cancer treatments using conventional methods like chemotherapy and radiotherapy were not convincing due to its post-treatment toxicity in the host. In Photodynamic Therapy (PDT), three individual non-toxic components including a photosensitizer, light source and oxygen cause damage to the cells and tissues when they are combined.

OBJECTIVE

In recent years, phytochemicals are being increasingly recognized as potent complementary drugs for cancer because of its natural availability, less toxicity and therapeutic efficiency in par with commercial drugs. Hence, the idea of using phytochemicals as natural photosensitizers in PDT resulted in a multiple pool of research studies with promising results in preclinical and clinical investigations.

METHODS

In this review, the potential of phytochemicals to act as natural photosensitizers for PDT, their mode of action, drawbacks, challenges and possible solutions are discussed in detail.

RESULTS

In PDT, natural photosensitizers, when used alone or in combination with other photosensitizers, induced cell death by apoptosis and necrosis, increased oxidative stress, altered cancer cell death signaling pathways, increased cytotoxicity and DNA damage in cancer cells. The pro-oxidant nature of certain antioxidant polyphenols, hormesis phenomenon, Warburg effect and DNA damaging potential plays a significant role in the photosensitizing mechanism of phytochemicals in PDT.

CONCLUSION

This review explores the role of phytochemicals that can act as photosensitizers alone or in combination with PDT and its mechanism of action on different cancers.

Curcumin: Modern Applications for a Versatile Additive

The recent development of several methods for extracting curcumin from the root of the plant Curcuma longa has led to intensified research on the properties of curcumin and its fields of application. Following the studies and the accreditation of curcumin as a natural compound with antifungal, antiviral, and antibacterial properties, new fields of application have been developed in two main directions—food and medical, respectively. This review paper aims to synthesize the fields of application of curcumin as an additive for the prevention of spoilage, safety, and quality of food. Simultaneously, it aims to present curcumin as an additive in products for the prevention of bacterial infections and health care. In both cases, the types of curcumin formulations in the form of (nano)emulsions, (nano)particles, or (nano)composites are presented, depending on the field and conditions of exploitation or their properties to be used. The diversity of composite materials that can be designed, depending on the purpose of use, leaves open the field of research on the conditioning of curcumin. Various biomaterials active from the antibacterial and antibiofilm point of view can be intuited in which curcumin acts as an additive that potentiates the activities of other compounds or has a synergistic activity with them.

Nutraceuticals with anti-inflammatory and anti-oxidant properties as intervention for reducing the health effects of fine particulate matter: Potential and Prospects

Air pollution, especially particulate matter pollution adversely affects human health. A growing pool of evidence has emerged which underscores the potential of individual-level nutritional interventions in attenuating the adverse health impact of exposure to PM2.5. Although controlling emission and reducing the overall levels of air pollution remains the ultimate objective globally, the sustainable achievement of such a target and thus consequent protection of human health will require a substantial amount of time and concerted efforts worldwide. In the meantime, smaller-scale individual-level interventions that can counter the inflammatory or oxidative stress effects triggered by exposure to particulate matter may be utilized to ameliorate the health effects of PM2.5 pollution. One such intervention is incorporation of nutraceuticals in the diet. Here, we present a review of the evidence generated from various in vitro, in vivo and human studies regarding the effects of different anti-inflammatory and antioxidant nutraceuticals in ameliorating the health effects of particulate matter air pollution. The studies discussed in this review suggest that these nutraceuticals when consumed as a part of the diet, or as additional supplementation, can potentially negate the cellular level adverse effects of exposure to particulate pollution. The potential benefits of adopting a non-pharmacological diet-based approach to air pollution-induced disease management have also been discussed. We argue that before a nutraceuticals-based approach can be used for widespread public adoption, further research, especially human clinical trials, is essential to confirm the beneficial action of relevant nutraceuticals and to explore the safe limits of human supplementation and the risk of side effects. Future research should focus on systematically translating bench-based knowledge regarding nutraceuticals gained from in-vitro and in-vivo studies into clinically usable nutritional guidelines.

Current Trends in Drug Delivery System of Curcumin and its Therapeutic Applications

Curcumin is a poly phenolic compound extracted from turmeric. Over the past years, it has acquired significant interest among researchers due to its numerous pharmacological activities like anti- cancer, anti-alzheimer, anti-diabetic, anti-bacterial, anti-inflammatory and so on. However, the clinical use of curcumin is still obstructed due to tremendously poor bioavailability, rapid metabolism, lower gastrointestinal absorption, and low permeability through cell that makes its pharmacology thrilling. These issues have led to enormous surge of investigation to develop curcumin nano formulations which can overcome these restrictive causes. The scientists all across the universe are working on designing several drug delivery systems viz. liposomes, micelles, magnetic nano carriers, etc. for curcumin and its composites which not only improve its physiochemical properties but also enhanced its therapeutic applications. The review aims to systematically examine the treasure of information about the medicinal use of curcumin. This article delivers a general idea of the current study piloted to overwhelm the complications with the bioavailability of curcumin which have exhibited an enhanced biological activity than curcumin. This article explains the latest and detailed study of curcumin and its conjugates, its phytochemistry and biological perspectives and also proved curcumin as an efficient drug candidate for the treatment of numerous diseases. Recent advancements and futuristic viewpoints are also deliberated, which shall help researchers and foster commercial translations of improved nanosized curcumin combination for the treatment of various diseases.

Mitochondria-targeted curcumin loaded CTPP–PEG–PCL self-assembled micelles for improving liver fibrosis therapy

Liver fibrosis, originating from activated hepatic stellate cells (HSCs), is receiving much attention in the treatment of clinical liver disease. In this study, mitochondria-targeted curcumin (Cur) loaded 3-carboxypropyl-triphenylphosphonium bromide–poly(ethylene glycol)–poly(ε-caprolactone) (CTPP–PEG–PCL) micelles were constructed to prolong the systemic circulation of Cur, improve the bioavailability of Cur and play a precise role in anti-fibrosis. The prepared Cur–CTPP–PEG–PCL micelles with a spherical shape had satisfactory dispersion, low critical micelle concentration (CMC) and high encapsulation efficiency (92.88%). The CTPP modification endowed good endosomal escape ability to the CTPP–PEG–PCL micelles, and micelles could be selectively accumulated in mitochondria, thereby inducing the enhanced cell proliferation inhibition of HSC-T6 cells. Mitochondrial Membrane Potential (MMP) was greatly reduced due to the mitochondrial-targeting of Cur. Moreover, the system circulation of Cur was extended and bioavailability was significantly enhanced in vivo. As expected, Cur loaded CTPP–PEG–PCL micelles were more effective in improving liver fibrosis compared with Cur and Cur–mPEG–PCL micelles. In conclusion, the Cur–CTPP–PEG–PCL based micelles can be a potential candidate for liver fibrosis treatment in future clinical applications.

A mitochondria-targeting micelle system based on CTPP–PEG–PCL polymer was designed to deliver curcumin to active HSC-T6 cells and prolong the systemic circulation and bioavailability of curcumin in vivo for effective treatment of liver fibrosis.

Sensitivity of Papilloma Virus-Associated Cell Lines to Photodynamic Therapy with Curcumin-Loaded Liposomes

Simple Summary

Globally, the burden of papilloma virus-associated cancers is high. About 5% of all cancers worldwide are caused by the human papillomavirus (HPV). Photodynamic therapy (PDT) is considered as a useful therapeutic option to treat cancers, particularly those near the tissue surface, since it is typically well tolerated and less invasive with a lower risk of severe complications as compared to conventional treatment strategies. PDT requires the combination of a photosensitizer, light of a specific wavelength, and tissue oxygen. In the present study, we examined the effectiveness of PDT together with a curcumin (liposome)-based photosensitizer in three papilloma virus-associated cell lines. PDT with curcumin liposomes could inhibit proliferation, cell migration, and colony formation of the tested tumor cells. The results suggest that curcumin-encapsulated liposomes in conjunction with PDT could be a useful tool for the treatment of papilloma virus-associated tumors.

Abstract

Photodynamic therapy (PDT) is a minimally invasive therapeutic approach used in the treatment of various medical conditions and cancerous diseases, involving light, a photosensitizing substance, and oxygen. Curcumin, a naturally occurring compound, carries antitumor activities and potentially could be exploited as a photosensitizer in PDT. Only little is known about liposomal-encapsulated curcumin that could help in increasing the efficacy, stability, and bioavailability of this compound. This study investigates the in vitro effects of curcumin-loaded liposomes in combination with PDT. Three papilloma virus-associated cell lines were treated with curcumin-loaded liposomes corresponding to a curcumin concentration of 0–100 µmol/L for 4 h followed by illumination at 457 nm (blue) for 45, 136, and 227 s at a fluence of 220.2 W/m² (100 mA) corresponding to 1, 3 and 5 J·cm⁻². After 24 h, the biological outcome of the treatment was assessed with the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), SYTO9/PI (propidium iodide), Annexin V-FITC (fluorescein isothiocyanate)/PI, clonogenic survival, and scratch (wound closure) assays. Photoactivation of curcumin-loaded liposomes led to a significant reduction in colony formation and migratory abilities, as well as to an increase in tumor cell death. The results point to the combination of curcumin-loaded liposomes with PDT as a potentially useful tool for the treatment of papillomavirus-associated malignancies.

Spray-dried multidrug particles for pulmonary co-delivery of antibiotics with N-acetylcysteine and curcumin-loaded PLGA-nanoparticles

Nowadays, the resistance of bacterial biofilms towards the available antibiotics is a severe problem. Therefore, many efforts were devoted to develop new formulations using nanotechnology. We have developed an inhalable microparticle formulation using spray-drying combining multiple drugs: an antibiotic (tobramycin, ciprofloxacin or azithromycin), N-acetylcysteine (NAC), and curcumin (Cur). The use of PLGA nanoparticles (NP) also allowed incorporating curcumin to facilitate spray drying and modify the release of some compounds. The aerosolizable microparticles formulations were characterized in terms of size, morphology, and aerodynamic properties. Biocompatibility when tested on macrophage-like cells was acceptable after 20 h exposure for concentrations up to at least 32 µg/mL. Antibacterial activity of free drugs versus drugs in the multiple drug formulations was evaluated on P. aeruginosa in the same range. When co-delivered the efficacy of tobramycin was enhanced compared to the free drug for the 1 µg/mL concentration. The combinations of azithromycin and ciprofloxacin with NAC and Cur did not show an improved antibacterial activity. Bacteria-triggered cytokine release was not inhibited by free antibiotics, except for TNF-α. In contrast, the application of NAC and the addition of curcumin-loaded PLGA NPs showed a higher potential to inhibit TNF-α, IL-8, and IL-1β release. Overall, the approach described here allows simultaneous delivery of antibacterial, mucolytic, and anti-inflammatory compounds in a single inhalable formulation and may therefore pave the way for a more efficient therapy of pulmonary infections.

Enhancement of Phthalocyanine Mediated Photodynamic Therapy by Catechin on Lung Cancer Cells

Worldwide, lung cancer remains one of the leading cancers with increasing mortality rates. Though chemotherapy for lung cancer is effective, it is always accompanied by unavoidable and grave side effects. Photodynamic therapy (PDT), using novel photosensitizers, is an advanced treatment method with relatively few side effects. Plant products are emerging as potent photosensitizers (PSs). The dose-dependent effect of Catechin (CA) (20–100 µM) on cellular morphological changes, cell viability, cytotoxicity, proliferation, DNA damage and apoptosis were studied on A549 adenocarcinoma alveolar basal epithelial cells. The effect of CA, along with Zinc phthalocyanine PS at 680 nm and 5 J/cm² fluency was also studied. As the doses of CA increased, the results showed a pattern of increased cytotoxicity, accompanied by decreased cell viability and proliferation in A549 cells. Also, at 52 µM (IC₅₀), CA in combination with PS significantly increased the cytotoxicity, DNA damage, and apoptosis, as compared to control and PS alone, treated cells in PDT experiments. These findings leave a possible thread that CA can be used in the application of phyto-photodynamic therapy of cancer in future.

Photodynamic inactivation of circulating tumor cells: An innovative approach against metastatic cancer

The spread of a primary malignant tumor is the major reason for most of the cancer-associated deaths. To this day, treatment regimen and available drugs are still insufficient to manage these conditions. In this work, a new therapeutic concept based on photodynamic therapy (PDT) of metastasis-initiating cells is introduced. To address this issue, an experimental model was developed to simulate the movement and photodynamic inactivation of circulating tumor cells (CTCs) in vitro. Using curcumin loaded poly(lactic-co-glycolic acid) nanoparticles, a significant reduction in the cell viability of human breast cancer cells (MDA-MB-231) could be achieved after 30 min laser irradiation (λ = 447 nm, P = 100mW) under flow conditions (5 cm s^-1). Confocal laser scanning microscopy images confirmed the immediate accumulation of curcumin on the cell membrane and an increased fluorescence signal after irradiation. PDT caused time-dependent morphological cell alterations (i.e. membrane evaginations and disruption) indicating apoptosis and early necrosis. During the photoactivation of curcumin, a blue shift in the absorption spectra and a decrease in the curcumin content could be determined. This study confirms that the presented experimental model is suitable for in vitro investigations of CTCs under in vivo-like conditions, at the same time encouraging the clinical implementation of PDT as an innovative strategy against metastasis.

Hyaluronic acid hydrophilic surface rehabilitating curcumin nanocrystals for targeted breast cancer treatment with prolonged biodistribution

Due to its high therapeutic efficiency and low systemic toxicity, natural bioactive curcumin has attracted more and more attention as a potential antineoplastic drug.