Detailed investigation of ROS arisen from chlorophyll a/Chitosan based-biofilm

Sodium copper chlorophyllin-loaded chitosan nanoparticle-based photodynamic therapy for B16 melanoma cancer cells

Melanoma is one of the most aggressive and fatal skin cancers owing to its ability to metastasize and develop resistance to chemotherapy. Photodynamic therapy (PDT) is a minimally noninvasive treatment modality comprising photosensitizers (PSs), light sources, and endogenous molecular oxygen that exert a localized cytotoxic effect on cancer cells. The current study explores the therapeutic potential of sodium copper chlorophyllin-loaded chitosan nanoparticles (CH-SCC NPs) along with handheld laser-based PDT on B16 cancer cells. A modified chlorophyll derivative identified as sodium copper chlorophyllin (SCC) is a dietary supplement that has anticancer properties. Herein, we have synthesized CH-SCC NPs using the ionic gelation method to enhance the PS's bioavailability and efficiency. Chitosan nanoparticles exhibited high biocompatibility in a normal cell line L929, zebrafish, and chick embryos, and were successfully employed to deliver the SCC to cancer cells. CH-SCC NPs showed an enhanced PDT effect that killed approximately 80%-85% of B16 cells. CH-SCC NPs in combination with a handheld portable laser source showed significant therapeutic potential against the B16 skin cancer cell line. The experimental findings further strengthen our device-repurposing strategy, which suggests that SCC nanoformulations along with handheld laser can be a suitable treatment for skin cancer even in remote areas where power source and treatment cost can be a limitation.

Cell-derived nanomaterials for biomedical applications

The ever-growing use of nature-derived materials creates exciting opportunities for novel development in various therapeutic biomedical applications. Living cells, serving as the foundation of nanoarchitectonics, exhibit remarkable capabilities that enable the development of bioinspired and biomimetic systems, which will be explored in this review. To understand the foundation of this development, we first revisited the anatomy of cells to explore the characteristics of the building blocks of life that is relevant. Interestingly, animal cells have amazing capabilities due to the inherent functionalities in each specialized cell type. Notably, the versatility of cell membranes allows red blood cells and neutrophils' membranes to cloak inorganic nanoparticles that would naturally be eliminated by the immune system. This underscores how cell membranes facilitate interactions with the surroundings through recognition, targeting, signalling, exchange, and cargo attachment. The functionality of cell membrane-coated nanoparticles can be tailored and improved by strategically engineering the membrane, selecting from a variety of cell membranes with known distinct inherent properties. On the other hand, plant cells exhibit remarkable capabilities for synthesizing various nanoparticles. They play a role in the synthesis of metal, carbon-based, and polymer nanoparticles, used for applications such as antimicrobials or antioxidants. One of the versatile components in plant cells is found in the photosynthetic system, particularly the thylakoid, and the pigment chlorophyll. While there are challenges in consistently synthesizing these remarkable nanoparticles derived from nature, this exploration begins to unveil the endless possibilities in nanoarchitectonics research.

Realizing Eco-Friendly Water-Resistant Sodium-Alginate-Based Films Blended with a Polyphenolic Aqueous Extract from Grape Pomace Waste for Potential Food Packaging Applications

Water-resistant and environmentally friendly sodium-alginate-based films have been investigated to develop functional materials to extend the food's shelf-life. A water-stable alginate-based film was prepared, employing both the internal and external gelation approach in the presence of CaCl₂. To apply this film to food packaging and thus preserve food quality, the aim of this work is to perform a chemical and physical characterization of the proposed materials, evidencing the main features and stability under different work conditions. Water contact angle measurements showed a value of 65°, suggesting an important reduced hydrophilic character of the obtained alginate films due to the novel CaCl₂-induced compacted polymer network. The film's stability was thus checked through swelling measurements in water after varying pH, temperature, and ionic strength. The film was stable at high temperatures and not pH-responsive. Only highly concentrated salt-based solutions negatively affected the proposed packaging, causing a large swelling. Furthermore, a water-based polyphenolic extract from grape (Vitis vinifera L.) pomace waste was embedded inside the films in different amounts in order to confer additional properties. The extract's polyphenolic content (evaluated from HPLC/MS-MS measurements) endowed the films' UV-light screening and enhanced antioxidant properties. These important findings suggest the additional potential role of these films in protecting food from light deterioration. The stability of these hybrid films was also checked by observation, as the polyphenols' presence did not largely alter the alginate network that occurred yet was water-resistant under the described work conditions.

Contributions of photochemistry to bio-based antibacterial polymer materials

Surgical site infections constitute a major health concern that may be addressed by conferring antibacterial properties to surgical tools and medical devices via functional coatings. Bio-sourced polymers are particularly well-suited to prepare such coatings as they are usually safe and can exhibit intrinsic antibacterial properties or serve as hosts for bactericidal agents. The goal of this Review is to highlight the unique contribution of photochemistry as a green and mild methodology for the development of such bio-based antibacterial materials. Photo-generation and photo-activation of bactericidal materials are illustrated. Recent efforts and current challenges to optimize the sustainability of the process, improve the safety of the materials and extend these strategies to 3D biomaterials are also emphasized.

Supramolecular nanomedicine derived from cucurbit[7]uril-conjugated nano-graphene oxide for multi-modality cancer therapy

Nano-graphene oxide (NGO) has attracted increasing attention as an advanced drug delivery system. However, the current surface functionalization and drug-loading of NGO either rely on π-π stacking that is limited to aromatic molecules, or covalent conjugation that requires tedious synthesis. Herein, we developed the first cucurbit[7]uril (CB[7])-conjugated NGO (NGO-CB[7]) that allows non-covalent, modular surface functionalization and drug loading via not only traditional π-π stacking interactions between the NGO surface and functional molecules, but also strong host-guest interactions between CB[7] and guest payloads or adamantane (ADA)-tagged functional molecules, for more versatile biomedical applications. To this end, chlorin e6 (Ce6, a photosensitizer), banoxantrone dihydrochloride (AQ4N, a hypoxia-responsive prodrug) and oxaliplatin (OX, a guest of CB[7]) were co-loaded onto NGO-CB[7] via π-π stacking and host-guest interactions, respectively. Subsequently, ADA-tagged hyaluronic acid (ADA-HA) wrapped NGO-CB[7] non-covalently via CB[7]-ADA host-guest interactions to improve the physiological stability and overall biocompatibility of this supramolecular nanosystem, and to enable targeted delivery into cancer cells with CD44 receptors overexpressed. Remarkably, this supramolecular nanomedicine exhibited significant antitumor efficacy via combined photothermal/photodynamic therapy (PTT/PDT) from NGO/Ce6, as well as dual chemotherapy from OX and AQ4N (activated by PDT-enhanced hypoxia), in vitro and in vivo. This study not only offers a new supramolecular inorganic/organic hybrid nanosystem for multi-modality cancer therapy, but may also provide important new insights into noncovalent functionalization of other carbon nanomaterials and inorganic nanomaterials leading to multifunctional drug delivery systems.

Development of Spirulina sea-weed raw extract/polyamidoamine hydrogel system as novel platform in photodynamic therapy: Photostability and photoactivity of chlorophyll a

The aim of this paper is to present and characterize Polyamidoamine-based hydrogels (PAA) as scaffolds to host photoactive Chlorophyll a (Chl a) from Spirulina (Arthrospira platensis) sea-weed Extract (SE), for potential applications in Photodynamic Therapy (PDT). The pigment extracted from SE was blended inside PAA without further purification, according to Green Chemistry principles. A comprehensive investigation of this hybrid platform, PAA/SE-based, was thus performed in our laboratory and, by means of Visible absorption and emission spectroscopies, the Chl a features, stability and photoactivity were studied. The obtained results evidenced the presence of two main Chl a forms, monomeric and dimeric, interacting with hydrogel polyamidoamines network. To better understand the nature of this interaction, the spectroscopic investigation of this system was performed both before and after the solidification of the hydrogel, that occurred at least in 24 h. Then, focusing the attention on solid scaffold, the ¹Chl a^⁎ fluorescence lifetime and FTIR-ATR analyses of PAA/SE were carried out, confirming the findings. The swelling and Point Zero Charge (PZC) measurements of solid PAA and PAA/SE were additionally performed to investigate the hydrogel behavior in water. Chl a molecules blended in PAA were (photo) stable and photoactive, and this latter feature was demonstrated showing that the pigment induced, when swelled in water and under irradiation, the formation of singlet oxygen (¹O₂), measured by direct and indirect methods.

Photodynamic therapy regulates fate of cancer stem cells through reactive oxygen species

Photodynamic therapy (PDT) is an effective and promising cancer treatment. PDT directly generates reactive oxygen species (ROS) through photochemical reactions. This oxygen-dependent exogenous ROS has anti-cancer stem cell (CSC) effect. In addition, PDT may also increase ROS production by altering metabolism, endoplasmic reticulum stress, or potential of mitochondrial membrane. It is known that the half-life of ROS in PDT is short, with high reactivity and limited diffusion distance. Therefore, the main targeting position of PDT is often the subcellular localization of photosensitizers, which is helpful for us to explain how PDT affects CSC characteristics, including differentiation, self-renewal, apoptosis, autophagy, and immunogenicity. Broadly speaking, excess ROS will damage the redox system and cause oxidative damage to molecules such as DNA, change mitochondrial permeability, activate unfolded protein response, autophagy, and CSC resting state. Therefore, understanding the molecular mechanism by which ROS affect CSCs is beneficial to improve the efficiency of PDT and prevent tumor recurrence and metastasis. In this article, we review the effects of two types of photochemical reactions on PDT, the metabolic processes, and the biological effects of ROS in different subcellular locations on CSCs.

Cremophor EL Nano-Emulsion Monomerizes Chlorophyll a in Water Medium

In this paper, the application of a non-ionic detergent Cremophor EL for monomerization of chlorophyll a in an aqueous medium is studied. The spectrophotometric properties of chlorophyll a encapsulated into the Cremophor EL nano-emulsion system were characterized by electronic absorption, steady-state and time-resolved fluorescence as well as circular dichroism spectroscopy. The results have shown that chlorophyll a dissolves more efficiently in the aqueous medium containing low-level Cremophor (5 wt%) than at an ethanolic solution even in the concentration of 10⁻⁴ M. The molecular organization of the chlorophyll a in the Cremophor EL nano-micelles was also investigated by means of Raman spectroscopy. The spectral changes in the frequency of the C=O stretching group were used to distinguish the aggregation state of chlorophyll. It was revealed that chlorophyll a exists dominantly in the monomeric form in the Cremophor EL aqueous solution. The promising aspect of the use of Cremophor EL nano-emulsion as a delivery system is to maintain stable chlorophyll monomer in an aqueous medium. It would open the potential for a new, practical application of chlorophyll a in medicine, as a dietary supplement or studies on molecular organization of chlorophyll a in the well-defined artificial system.

Porphyrinoid-Cyclodextrin Assemblies in Biomedical Research: An Update

Porphyrinoids, well-known cofactors in fundamental processes of life, have stimulated interest as synthetic models of natural systems and integral components of photodynamic therapy, but their utilization is compromised by self-aggregation in aqueous media. The capacity of cyclodextrins to include hydrophobic molecules in their cavity provides porphyrinoids with a protective environment against oxidation and the ability to disperse efficiently in biological fluids. Moreover, engineered cyclodextrin-porphyrinoid assemblies enhance the photodynamic abilities of porphyrinoids, can carry chemotherapeutics for synergistic modalities, and can be enriched with functions including cell recognition, tissue penetration, and imaging. This Perspective includes synthetic porphyrinoid-cyclodextrin models of proteins participating in fundamental processes, such as enzymatic catalysis, respiration, and electron transfer. In addition, since porphyrinoid-cyclodextrin systems comprise third generation photosensitizers, recent developments for their utilization in photomedicine, that is, multimodal therapy for cancer (e.g., PDT, PTT) and antimicrobial treatment, and eventually in biocompatible therapeutic or diagnostic platforms for next-generation nanomedicine and theranostics are discussed.

Removal of tetracycline from polluted water by chitosan-olive pomace adsorbing films

This paper focuses on the removal of tetracycline from polluted water by chitosan-olive pomace adsorbing films. More specifically, both raw olive solid wastes (olive pomace) and the olive solid wastes/chitosan composite were compared and used for this purpose. Adsorption capacities values of 16 mg × g^-1 and 1.6 mg × g^-1 were obtained for the two adsorbents respectively. However, chitosan/olive pomace is proposed as suitable for environmental applications avoiding the dispersion of the pomace blocked inside the chitosan film. To detail the adsorption process, the effect of several experimental parameters such as the pH values, ionic strength, amount of adsorbent and pollutant and temperature values was investigated. The results showed that the adsorption process improved increasing the pH values, with a maximum at pH 8, and it was negatively affected by the presence of salts that retarded the adsorption. Indeed, the desorption of tetracycline was obtained in a MgCl₂ 2 M solution. So, a low-cost and cleaner approach, fundamental for the pollutant recovery and for an adsorbent safe reuse, for several cycles of adsorption/desorption, transforming a waste in resource is presented. The kinetics, isotherms models of adsorption and the thermodynamic parameters (ΔG°, ΔH° and ΔS°) were also evaluated observing that the physisorption of the pollutant occurred with and an endothermic character (ΔH° > 0) with ΔG° < 0 and ΔS° > 0. The use of Advanced Oxidation Processes was proposed as possible alternative to the tetracycline recovery, obtaining its degradation after the desorption. With the present paper, the alternative reuse of olive pomace is reported avoiding its disposal in the environment claiming its potential in the removal/recover of emerging contaminants from water.

Chitosan Biopolymer from Crab Shell as Recyclable Film to Remove/Recover in Batch Ketoprofen from Water: Understanding the Factors Affecting the Adsorption Process

Seafood, a delight for many people, is sold in the market as a wide variety of products. However, seafood industries produce many by-products; for example, during the processing, the heads and shells of shellfish are generated as waste. This results in the generation of a large amount of shell waste that is accumulated over time, inducing a major environmental concern. Effective solutions for recycling shell waste should be taken into consideration, and the extraction of commercially useful substances like chitin and its derivates, such as chitosan, could be a valid solution for reducing the seafood waste’s environmental impact. Thus, during this work, we propose the use of chitosan as biowaste, to induce the formation of solid films useful for decontaminating water from emerging pollutants. In particular, ketoprofen was used as a model contaminant, and a high percentage of removal, at least 90%, was obtained in a short time under our experimental conditions. Thus, a comprehensive investigation into the adsorption of ketoprofen onto chitosan film was performed, detailing the nature of the adsorption by studying the effects of pH, temperature changes, and electrolyte presence in the solutions containing the pollutant. The process was found to be pH-dependent, involving meanly electrostatic interactions between the pollutant molecules and chitosan. The endothermic character of the adsorption was inferred. The kinetics of the process was investigated, showing that the pseudo second-order kinetic model best fit the experimental data. A recycling process of the adsorbent was proposed; therefore, the adsorbed pollutant can be recovered by reusing the same adsorbent material for further consecutive cycles of adsorption without affecting the efficiency for ketoprofen removal from water.

Chitosan Film as Eco-Friendly and Recyclable Bio-Adsorbent to Remove/Recover Diclofenac, Ketoprofen, and their Mixture from Wastewater

This paper reported the first example on the use of chitosan films, without further modification, to remove and recover, through bio-sorption processes, the emerging pollutant Diclofenac from water. The latter was adopted as a model, among non-steroidal anti-inflammatory drugs, by obtaining a maximum adsorption capacity, q_max, on chitosan of about 10 mg/g, under the applied experimental conditions of work. The literature gap about the use of chitosan films, which was already used for dyes and heavy metals removal, to adsorb emerging pollutants from water was covered, claiming the wide range application of chitosan films to remove a different class of pollutants. Several parameters affecting the Diclofenac adsorption process, such as the pH and ionic strength of solutions containing Diclofenac, the amount of the bio-sorbent and pollutant, and the temperature values, were investigated. The kinetics and the adsorption isotherms, along with the thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were also evaluated. The process occurred very efficiently, and Chitosan/Diclofenac amounts dependent, remove about the 90% of the pollutant, in 2 h, from the tested solutions, through electrostatic interaction involving the carboxylic moiety of Diclofenac and Chitosan amino groups. This finding was confirmed by the pH and salt effects on the bio-sorption process, including swelling measurements of Chitosan films and by FTIR-ATR analysis. In detail, the maximum adsorption was observed at pH 5, when pollutant and Chitosan were negatively and positively charged, respectively. By reducing or increasing the pH around this value, a reduced affinity was observed. Accordingly, the presence of salts retarded the Diclofenac removal screening its charges, which hinders the interaction with Chitosan. The sorption was spontaneous (ΔG° < 0) and endothermic (ΔH° > 0) following the pseudo-second order kinetic model. The process was Diclofenac and Chitosan amount dependent. In addition, the Freundlich and Temkin isotherms well described the process, which showed the heterogeneous character of the process. Experiments of the complete desorption were also performed by using NaCl solutions 0.25 M (like sea water salt concentration) proposing the reuse of the pollutant and the recycling of the bio-sorbent lowering the associated costs. The versatility of the adsorbent was reported by exploring the possibility to induce the Diclofenac light-induced degradation after the adsorption and by-products adsorption onto chitosan films. To emphasize the chitosan capacity of treating water, the removal of another pollutant such as Ketoprofen and the mixture of Diclofenac and Ketoprofen were investigated. In this way, a green and eco-friendly production-pollution prevention technology for removing emerging pollutants from water was presented, which reduced the overall environmental impact. This illustrated experiments both in static and dynamic conditions for potential industrial applications.

Photodynamic Chitosan Nano-Assembly as a Potent Alternative Candidate for Combating Antibiotic-Resistant Bacteria

The fact that increasing antibiotic resistance of pathogenic bacteria and a lack of new potent broad-spectrum antibiotics call for the development of alternative approaches for treating infectious diseases. With the merits of great efficacy, safety, and facile implementation, antibacterial photodynamic therapy (APDT) represents an attractive modality for this purpose. Here, we report that the newly fabricated photodynamic chitosan nano-assembly, designated CS-Ce6, could synergistically kill antibiotic-resistant bacteria with superior potency to vancomycin. CS-Ce6 nano-assembly, obtained from covalent conjugate of chlorin e6 (Ce6) with chitosan, exhibited strong association with bacteria, thus altering their morphologies and mediating great delivery efficiency of Ce6. Upon light irradiation, localized generation of singlet oxygen by CS-Ce6 nano-assembly has a remarkable bactericidal effect toward both drug-resistance Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative Acinetobacter baumannii, which was greater than that the free Ce6 and antibiotics had. We also confirmed that APDT-treated MRSA neither developed resistance to APDT nor altered their resistance to methicillin. Our in vivo studies demonstrated that the CS-Ce6 nano-assembly had comparable therapeutic efficacy with vancomycin in MRSA-infected mice. These results suggest that APDT by photodynamic chitosan nano-assembly hold great potential in combating antibiotic-resistant bacteria and hopefully in reducing the need of antibiotics in the future.

One pot environmental friendly synthesis of gold nanoparticles using Punica Granatum Juice: A novel antioxidant agent for future dermatological and cosmetic applications

HYPOTHESIS

The interesting properties of Gold Nanoparticles (AuNPs) make them attractive for different application fields such as cosmetology, medicine and clinical nanotechnologies. In this work a fast, easy and eco-friendly method for the AuNPs synthesis is proposed by using the Punica Granatum Juice (PGJ) with potential dermatological and cosmetic applications. The AuNPs antioxidant activity, due to the presence of phenols from the juice, and their use as booster for improving the Sun Protection Factor (SPF) in commercial sunscreen formulations, are thus expounded.

EXPERIMENTS

By using appropriate amounts of PGJ and HAuCl₄, under mild work conditions, AuNPs with a mean size of 100 ± 40 nm are observed and carefully characterized. Solution pH, temperature, and volume were also changed for optimizing the AuNPs formation and features. The antioxidant activity was studied, by evaluating the AuNP ability of scavenging the radical 2,2-diphenyl-1-picrylhydrazylhydrate (DPPH). This finding was confirmed performing special experiments focused on the reaction between AuNPs and H₂O₂, by using suitable probes, such as 4-thiothymidine (S⁴TdR) and Cytochrome-c (Cyt-c). The SPF value was also calculated.

FINDINGS

The synthetized AuNPs showed a surface plasmon in visible range at 577 nm and resulted stable for long time in aqueous medium, also changing the pH values in the range 2-12. The studied antioxidant activity, confirmed also by performing special experiments with suitable probes, demonstrated the high performance of AuNPs. The AuNP photostability under sun irradiation is also shown. The calculated SPF values were in the range 3-18, related to AuNPs concentration in the range 1.80 × 10^-12-1.00 × 10^-11 M. The same AuNPs concentrations were used for cellular experiments. Indeed, since the AuNPs-PGJ mediated will be potentially introduced by dermal contact, dermal fibroblasts (Human Dermal Fibroblasts, HDF) and Human Microvascular Endothelial Cells (HMVEC) were used to evaluate the possible effects of these nanoparticles as a preliminary step. The results indicated that an AuNP concentrations in the range 1.80 × 10^-12-3.60 × 10^-12 M could be adopted since they do not appeared cyctotoxic.

Chlorophyll a in cyclodextrin supramolecular complexes as a natural photosensitizer for photodynamic therapy (PDT) applications

Chlorophyll a (Chl a), an amphipathic porphyrin, was employed as natural photosensitizer for photodynamic therapy applications. Due to its lacking solubility in water and high tendency to aggregate, Chl a was included into different modified cyclodextrins (CDs) to form stable water-soluble supramolecular complexes. To achieve this aim, 2-Hydroxypropyl-β-cyclodextrin (2-HP-β-CD), 2-Hydroxypropyl-γ-cyclodextrin (2-HP-γ-CD), Heptakis(2,6-di-o-methyl)-β-cyclodextrin (DIMEB) and Heptakis(2,3,6-tri-o-methyl)-β-cyclodextrin (TRIMEB) were used. The chemical physical properties of Chl a/CD complexes in cellular medium were studied by means of UV-Vis absorption spectroscopy. Results demonstrated the good aptitude of 2-HP-γ-CD, and more particularly of 2-HP-β-CD, to solubilize the Chl a in cell culture medium in monomeric and photoactive form. Then, Chl a/2-HP-β-CD and Chl a/2-HP-γ-CD complexes were evaluated in vitro on human colorectal adenocarcinoma HT-29 cell line, and cytotoxicity and intracellular localization were respectively assessed. Further tests, such as phototoxicity, ROS generation, intracellular localization and mechanism of cell death were then focused exclusively on Chl a/2-HP-β-CD system. This complex exhibited no dark toxicity and a high phototoxicity toward HT-29 cells inducing cell death via necrotic mechanism. Therefore, it is possible to affirm that Chl a/2-HP-β-CD supramolecular complex could be a promising and potential formulation for applications in photodynamic therapy.