Carbon@polypyrrole nanotubes as a photosensitizer in laser phototherapy of Pseudomonas aeruginosa

Development of New Nanoniosome Carriers for Vorinostat: Evaluation of Anticancer Efficacy In Vitro

Vorinostat (VST) is a chemotherapeutic agent administrated for various types of cancers. However, it suffers from side effects and chemoresistance that reduce its application. Different nanoniosomes comprised Span 20, 60, 65 and 80 were prepared by the thin film hydration method and loaded with VST. The nanoniosomes were physicochemically characterized using particle size analysis and field emission scanning electron microscopy. The best formulation that was prepared using Span 65 (VST-NN-S65) included vesicle size of 127 nm with a narrow size distribution. VST-NN-S65 had an entrapment efficiency and loading capacity of 81.3 ± 5.1 and 32.0 ± 3.9 %, respectively. Drug release rate measurements showed that 90 % of VST was liberated within 1 h. Cytotoxicity assessments of VST-NN-S65 in HeLa and MCF7 cells indicated significant improvement in the effectiveness of VST, compared to the VST suspension. For VST-NN-S65, IC50 values of 26.3 and 6.6 μg mL-1 were obtained for HeLa and MCF7 cell lines, respectively. In situ apoptosis detection by the TUNEL assay revealed that apoptosis mainly occurred in the cell lines.

Ultralow Loading Copper-Intercalated MoO3 Nanobelts with High Activity against Antibiotic-Resistant Bacteria

In recent years, the infection rate of antibiotic resistance has been increasing year by year, and the prevalence of super bacteria has posed a great threat to human health. Therefore, there is an urgent need to find new antibiotic alternatives with long-term inhibitory activity against a broad spectrum of bacteria and microorganisms in order to avoid the proliferation of more multidrug-resistant (MDR) bacteria. The presence of natural van der Waals (vdW) gaps in layered materials allows them to be easily inserted by different guest species, providing an attractive strategy for optimizing their physicochemical properties and applications. Here, we have successfully constructed a copper-intercalated α-MoO3 nanobelt based on nanoenzymes, which is antibacterial through the synergistic effect of multiple enzymes. Compared with α-MoO3, MoO3-x/Cu nanobelts with a copper loading capacity of 2.11% possess enhanced peroxidase (POD) catalytic activity and glutathione (GSH) depletion, indicating that copper intercalation significantly improves the catalytic performance of the nanoenzymes. The MoO3-x/Cu nanobelts are effective in inducing POD and oxidase (OXD) and catalase (CAT) activities in the presence of H2O2 and O2, which resulted in the generation of large amounts of reactive oxygen species (ROS), which were effective in bacterial killing. Interestingly, MoO3-x/Cu nanobelts can serve as glutathione oxidase (GSHOx)-like nanoenzymes, which can deplete GSH in bacteria and thus significantly improve the bactericidal effect. The multienzyme-catalyzed synergistic antimicrobial strategy shows excellent antimicrobial efficiency against β-lactamase-producing Escherichia coli (ESBL-E. coli) and methicillin-resistant Staphylococcus aureus (MRSA). MoO3-x/Cu exhibits excellent spectral bactericidal properties at very low concentrations (20 μg mL-1). Our work highlights the wide range of antibacterial and anti-infective biological applications of copper-intercalated MoO3-x/Cu nanobelt catalysts.

A Review on Carbon Nanotubes Family of Nanomaterials and Their Health Field

The use of carbon nanotubes (CNTs), which are nanometric materials, in pathogen detection, protection of environments, food safety, and in the diagnosis and treatment of diseases, as efficient drug delivery systems, is relevant for the improvement and advancement of pharmacological profiles of many molecules employed in therapeutics and in tissue bioengineering. It has contributed to the advancement of science due to the development of new tools and devices in the field of medicine. CNTs have versatile mechanical, physical, and chemical properties, in addition to their great potential for association with other materials to contribute to applications in different fields of medicine. As, for example, photothermal therapy, due to the ability to convert infrared light into heat, in tissue engineering, due to the mechanical resistance, flexibility, elasticity, and low density, in addition to many other possible applications, and as biomarkers, where the electronic and optics properties enable the transduction of their signals. This review aims to describe the state of the art and the perspectives and challenges of applying CNTs in the medical field. A systematic search was carried out in the indexes Medline, Lilacs, SciELO, and Web of Science using the descriptors "carbon nanotubes", "tissue regeneration", "electrical interface (biosensors and chemical sensors)", "photosensitizers", "photothermal", "drug delivery", "biocompatibility" and "nanotechnology", and "Prodrug design" and appropriately grouped. The literature reviewed showed great applicability, but more studies are needed regarding the biocompatibility of CNTs. The data obtained point to the need for standardized studies on the applications and interactions of these nanostructures with biological systems.

Carbon Nanotubes for Targeted Therapy: Safety, Efficacy, Feasibility and Regulatory Aspects

It is crucial that novel and efficient drug delivery techniques be created in order to improve the pharmacological profiles of a wide variety of classes of medicinal compounds. Carbon nanotubes (CNTs) have recently come to the forefront as an innovative and very effective technique for transporting and translocating medicinal compounds. CNTs were suggested and aggressively researched as multifunctional novel transporters designed for targeted pharmaceutical distribution and used in diagnosis. CNTs can act as vectors for direct administration of pharmaceuticals, particularly chemotherapeutic medications. Multi-walled CNTs make up the great majority of CNT transporters, and these CNTs were used in techniques to target cancerous cells. It is possible to employ Carbon nanotubes (CNTs) to transport bioactive peptides, proteins, nucleic acids, and medicines by functionalizing them with these substances. Due to their low toxicity and absence of immunogenicity, carbon nanotubes are not immunogenic. Ammonium-functionalized carbon nanotubes are also attractive vectors for gene-encoding nucleic acids. CNTs that have been coupled with antigenic peptides have the potential to be developed into a novel and efficient approach for the use of synthetic vaccines. CNTs bring up an enormous number of new avenues for future medicine development depending on targets within cells, which have until now been difficult to access. This review focuses on the numerous applications of various CNT types used as medicine transport systems and on the utilization of CNTs for therapeutical purposes.

Photodynamic therapy for the treatment of Pseudomonas aeruginosa infections: A scoping review

BACKGROUND

Pseudomonas aeruginosa is a Gram-negative bacillus that causes superficial and deep infections, which can be minor to life-threatening. Recently, P. aeruginosa has gained significant relevance due to the increased incidence of multidrug-resistant (MDR) strains that complicate antibiotic treatment. Due to MDR strains, alternative therapies, such as antimicrobial photodynamic therapy (PDT), are presented as a good option to treat nonsystemic infections. PDT combines a photosensitizer agent (PS), light, and oxygen to generate free radicals that destroy bacterial structures such as the envelope, matrix, and genetic material. This work aimed to identify the development stage of the PDT applied to P. aeruginosa to conclude which research stage should be emphasized more.

METHODS

Systematic bibliographic search in various public databases was performed. Related articles were identified using keywords, and relevant ones were selected using inclusion and exclusion criteria according to the PRISMA protocol.

RESULTS

We found 29 articles that meet the criteria, constituting a good body of evidence associated with using PDT against P. aeruginosa in vitro and less developed for in vivo research.

CONCLUSIONS

We conclude that PDT could become an effective adjunct to antimicrobial therapy against P. aeruginosa. This effectiveness depends on the PS used and the location of the infection. Many PS already demonstrated efficacy in PDT, but the evidence is supported significantly by in vitro and very few in vivo studies. Therefore, we conclude that further research efforts should focus on demonstrating the safety and efficacy of these PSs in vivo in animal infection models.

Antimicrobial Photodynamic Therapy: Latest Developments with a Focus on Combinatory Strategies

Antimicrobial photodynamic therapy (aPDT) has become a fundamental tool in modern therapeutics, notably due to the expanding versatility of photosensitizers (PSs) and the numerous possibilities to combine aPDT with other antimicrobial treatments to combat localized infections. After revisiting the basic principles of aPDT, this review first highlights the current state of the art of curative or preventive aPDT applications with relevant clinical trials. In addition, the most recent developments in photochemistry and photophysics as well as advanced carrier systems in the context of aPDT are provided, with a focus on the latest generations of efficient and versatile PSs and the progress towards hybrid-multicomponent systems. In particular, deeper insight into combinatory aPDT approaches is afforded, involving non-radiative or other light-based modalities. Selected aPDT perspectives are outlined, pointing out new strategies to target and treat microorganisms. Finally, the review works out the evolution of the conceptually simple PDT methodology towards a much more sophisticated, integrated, and innovative technology as an important element of potent antimicrobial strategies.

Carbon Nanotubes: Current Perspectives on Diverse Applications in Targeted Drug Delivery and Therapies

Current discoveries as well as research findings on various types of carbon nanostructures have inspired research into their utilization in a number of fields. These carbon nanostructures offer uses in pharmacy, medicine and different therapies. One such unique carbon nanostructure includes carbon nanotubes (CNTs), which are one-dimensional allotropes of carbon nanostructure that can have a length-to-diameter ratio greater than 1,000,000. After their discovery, CNTs have drawn extensive research attention due to their excellent material properties. Their physical, chemical and electronic properties are excellent and their composites provide great possibilities for enormous nanometer applications. The current study provides a systematic review based on prior literature review and data gathered from various sources. The various research studies from many research labs and organizations were systematically retrieved, collected, compiled and written. The entire collection and compilation of this review concluded the use of CNT approaches and their efficacy and safety for the treatment of various diseases such as brain tumors or cancer via nanotechnology-based drug delivery, phototherapy, gene therapy, antiviral therapy, antifungal therapy, antibacterial therapy and other biomedical applications. The current review covers diverse applications of CNTs in designing a range of targeted drug delivery systems and application for various therapies. It concludes with a discussion on how CNTs based medicines can expand in the future.

SnS Nanosheets for Rapid and Effective Bacteria Sterilization Under Near-infrared Irradiation

Today, the threat of pathogenic bacterial infection worldwide that leads to the increase of mortality rate strongly demands the development of new antibacterial agents that can kill bacteria quickly and effectively. Although there are a lot of antibacterial agents that have been developed so far, few studies on the antibacterial performance of SnS have been investigated at 808 nm laser. Here, we synthesized SnS nanosheets with strong near-infrared absorption performance and excellent antibacterial performance via a simple solvothermal synthesis route. The as-prepared SnS nanosheets showed excellent photothermal conversion efficiency (38.7 %), photodynamic performance, and photostability, and at the same time 99.98 % and 99.7 % sterilization effect against Gram-negative Escherichia coli (E. coli) and Gram-positive Bacillus subtilis (B. subtilis) under near-infrared irradiation (808 nm, 1.5 W/cm² ). This study suggests that SnS nanosheets could be a promising candidate for antibacterial therapy owing to the synergetic effects of photothermal and photodynamic performance.

State of the Art in the Antibacterial and Antiviral Applications of Carbon-Based Polymeric Nanocomposites

The development of novel approaches to prevent bacterial infection is essential for enhancing everyday life. Carbon nanomaterials display exceptional optical, thermal, and mechanical properties combined with antibacterial ones, which make them suitable for diverse fields, including biomedical and food applications. Nonetheless, their practical applications as antimicrobial agents have not been fully explored yet, owing to their relatively poor dispersibility, expensiveness, and scalability changes. To solve these issues, they can be integrated within polymeric matrices, which also exhibit antimicrobial activity in some cases. This review describes the state of the art in the antibacterial applications of polymeric nanocomposites reinforced with 0D fullerenes, 1D carbon nanotubes (CNTs), and 2D graphene (G) and its derivatives such as graphene oxide (GO) and reduced graphene oxide (rGO). Given that a large number of such nanocomposites are available, only the most illustrative examples are described, and their mechanisms of antimicrobial activity are discussed. Finally, some applications of these antimicrobial polymeric nanocomposites are reviewed.

Facile antibacterial materials with turbine-like structure for P. aeruginosa infected scald wound healing

Pseudomonas aeruginosa (P. aeruginosa) is a popular hospital pathogen and the major cause of morbidity and mortality in patients with cystic fibrosis (CF) and impaired immune system. Herein, we designed and synthesized a series of organic molecules MTEBT-n (n = 1, 2, 3) to specifically and effectively kill P. aeruginosa. Hydrophobic triphenylamine was selected as the skeleton, and hydrophilic primary ammonium salts that can easily penetrate the cell walls of Gram-negative bacteria and accumulate in the bacteria were used to adjust the hydrophilic-hydrophobic ratio of the molecules, resulting in different antibacterial activity. As the hydrophilic-hydrophobic ratio increased in the structures from MTEBT-1 to MTEBT-3, the antibacterial activity of the three molecules were gradually enhanced with killing effects of 25%, 75% and 95% against P. aeruginosa, respectively. The antibacterial mechanisms of MTEBT-n were demonstrated to destroy the bacterial membrane, which could effectively prevent the development of drug resistance. In addition, MTEBT-3 with the highest antibacterial activity could inhibit P. aeruginosa biofilm very well, and heal the P. aeruginosa infected scald wounds. This work provides a potential organic antimicrobial material for clinical antimicrobial therapy of P. aeruginosa infection, and offers a molecular engineering strategy for designing new antimicrobials.

NIR Photoregulated Theranostic System Based on Hexagonal-Phase Upconverting Nanoparticles for Tumor-Targeted Photodynamic Therapy and Fluorescence Imaging

Although photodynamic therapy (PDT) is an effective, minimally invasive therapeutic modality with advantages in highly localized and specific tumor treatments, large and deep-seated cancers within the body cannot be successfully treated due to low transparency to visible light. To improve the therapeutic efficiency of tumor treatment in deep tissue and reduce the side effects in normal tissue, this study developed a near-infrared (NIR)-triggered upconversion nanoparticle (UCNP)-based photosensitizer (PS) carrier as a new theranostics system. The NaYF4:Yb/Er UCNPs were synthesized by a hydrothermal method, producing nanoparticles of a uniformly small size (≈20 nm) and crystalline morphology of the hexagonal phase. These UCNPs were modified with folic acid-conjugated biocompatible block copolymers through a bidentate dihydrolipoic acid linker. The polymer modified hexagonal phase UCNPs (FA-PEAH-UCNPs) showed an improved dispersibility in the aqueous solution and strong NIR-to-vis upconversion fluorescence. The hydrophobic PS, pheophorbide a (Pha), was then conjugated to the stable vectors. Moreover, these UCNP-based Pha carriers containing tumor targeting folic acid ligands exhibited the significantly enhanced cellular uptake efficiency as well as PDT treatment efficiency. These results suggested that this system could extend the excitation wavelength of PDT to the NIR region and effectively improve therapeutic efficiency of PSs.

Synthesis of Flower-like Nickel Hydroxide Nanosheets and Application in Electrochemical Determination of Famotidine

An electrochemical sensor was designed and fabricated for electrocatalytic oxidation and determination of famotidine in pharmaceutical forms. The electrochemical oxidation process and its kinetics were investigated using cyclic voltammetry, steady-state polarization measurements, and chronoamperometry techniques, and also the analytical measurements were performed by amperometry. Upon addition of the drug into the solution, cyclic voltammograms of the fabricated sensor exhibited an increased anodic peak current associated with a decrease in the corresponding cathodic current. These results suggested an electrocatalytic EC’ oxidation mechanism for famotidine on the oxyhydroxide species immobilized on the electrode surface. Accordingly, a mechanism involving generation of Ni³⁺ active sites and their subsequent consumption by the drug was proposed. Moreover, the corresponding rate law under the control of charge transfer was developed and kinetic parameters were derived. A sensitive and time-saving amperometric procedure was also developed for the analysis of famotidine with a detection limit of 5.91 mmol L^-1. Using the developed amperometric procedure, famotidine was successfully analyzed in the presence of ibuprofen. The developed sensor in this study displayed enhanced sensitivity and selectivity, compared to some other reported methods.

Nanostructured antimicrobial peptides: The last push towards clinics

Peptide drugs hold great potential for the treatment of infectious diseases due to their unconventional mechanisms of action, biocompatibility, biodegradability and ease of synthesis and modification. The increasing rising of bacterial strains resistant to classical antibiotics have pushed the development of new peptide-based antimicrobial therapies. In this context, over the past few years, different approaches have reached a clinical approval. Furthermore, the application of nanotechnological principles to the design of antimicrobial peptide-based composites increases even more the already known benefits of antimicrobial peptides as competent protein drugs. Then, we provide here an overview of the current strategies for antimicrobial peptide discovery and modification and the status of such peptides already under clinical development. In addition, we summarize the innovative formulation strategies for their application, focusing on the controlled self-assembly for the fabrication of antimicrobial nanostructures without the assistance of external nanocarriers, and with emphasis on bioengineering, design of ultra-short peptides and rising insights in bacterial selectivity.

Combined X-ray radiotherapy and laser photothermal therapy of melanoma cancer cells using dual-sensitization of platinum nanoparticles

Metal nanostructures are promising agents sensitizing by laser light and X-ray in photothermal therapy (PTT) and radiotherapy (RT) of cancer that improve treatment strategies of cancer. Nanoscale platinum materials are favorable in nanomedicine applications. In this study, platinum nanoparticles (PtNPs) were synthesized and applied for cancer therapy upon 808-nm laser light and X-ray radiation, or their combination. Two power densities of laser (1.0 and 1.5 W cm^-2) and three X-ray doses (2, 4 and 6 Gy) were selected for irradiation of B16/F10 cell line at 24 and 72 h-post treatment. The synthesized PtNPs had a spherical shape with a diameter of 12.2 ± 0.7 nm, and were cytocompatible up to 250 μg mL^-1. A photothermal conversion activity in a concentration-dependent manner at 72 h-post treatment was observed. Also, PtNPs represented cytotoxicity upon X-ray radiation doses of 2, 4, and 6 Gy after 24 h, while, 72-h time passing led to deeper outcomes. Dual radiation of laser light and X-ray into PtNPs considerably improved the treatment via reactive oxygen species (ROS) production. PtNPs can act as a novel dual absorber of laser light and X-ray, a common sensitizer, for treatment of cancer. The results of this study can be considered after further clinical investigations for treatment of tumor models.