scholarly journals Design of Photosensitizing Agents for Targeted Antimicrobial Photodynamic Therapy

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5239
Author(s):  
Maxime Klausen ◽  
Muhammed Ucuncu ◽  
Mark Bradley
Keyword(s):  
Photodynamic Therapy ◽  
Conventional Treatment ◽  
Building Blocks ◽  
Type I ◽  
Antimicrobial Photodynamic Therapy ◽  
Photodynamic Inactivation ◽  
Oxygen Species ◽  
Type Ii ◽  
Photosensitizing Agents ◽  
Recent Developments

Photodynamic inactivation of microorganisms has gained substantial attention due to its unique mode of action, in which pathogens are unable to generate resistance, and due to the fact that it can be applied in a minimally invasive manner. In photodynamic therapy (PDT), a non-toxic photosensitizer (PS) is activated by a specific wavelength of light and generates highly cytotoxic reactive oxygen species (ROS) such as superoxide (O2−, type-I mechanism) or singlet oxygen (1O2*, type-II mechanism). Although it offers many advantages over conventional treatment methods, ROS-mediated microbial killing is often faced with the issues of accessibility, poor selectivity and off-target damage. Thus, several strategies have been employed to develop target-specific antimicrobial PDT (aPDT). This includes conjugation of known PS building-blocks to either non-specific cationic moieties or target-specific antibiotics and antimicrobial peptides, or combining them with targeting nanomaterials. In this review, we summarise these general strategies and related challenges, and highlight recent developments in targeted aPDT.

scholarly journals Type I and Type II mechanisms of antimicrobial photodynamic therapy: An in vitro study on gram-negative and gram-positive bacteria

2012 ◽  
Vol 44 (6) ◽  
pp. 490-499 ◽  
Author(s):  
Liyi Huang ◽  
Yi Xuan ◽  
Yuichiro Koide ◽  
Timur Zhiyentayev ◽  
Masamitsu Tanaka ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
In Vitro Study ◽  
Vitro Study ◽  
Type I ◽  
Antimicrobial Photodynamic Therapy ◽  
Type Ii ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

scholarly journals PHOTODYNAMIC THERAPY: NEW LIGHT IN MEDICINE WORLD

2010 ◽  
Vol 8 (2) ◽  
pp. 279-291 ◽  
Author(s):  
Venny Santosa ◽  
Leenawaty Limantara
Keyword(s):  
Reactive Oxygen Species ◽  
Photodynamic Therapy ◽  
Side Effects ◽  
Reactive Oxygen Species Generation ◽  
Reactive Oxygen ◽  
Type I ◽  
Oxygen Species ◽  
Type Ii ◽  
Light Spectrum ◽  
Medical Field

Photodynamic therapy (PDT) is a considerably new kind of photochemotherapeutic treatment in medical field. It combines the use of three components, which are a photosensitizer, light and oxygen. Photosensitizer is a compound activated by light. The application can be oral, topical or intravenous. It usually member of porphyrin group with ampiphilic characteristics. Photosensitizer can be of generation I, II or III, each generation step develops more specificity, selectivity and deeper tissue application. This review will discuss photosensitizer development consecutively, with its benefit and lackness. The light used is usually on red region, while the oxygen is involved in reactive oxygen species generation. Its mechanism action can go through either in type I or type II reaction. This kind of therapy is usually being used in oncology, especially in superficial and in-lining cancers, dermatology and ophthalmology field. This therapy can be safely given to patients with complication and has distinct advantages compare with other treatment such as chemotherapy and surgery. It also considerably has lesser side effects and risks. Broader application is being developed through various experiments and photosensitizer modification.   Keywords: light spectrum, photoactivation, photodynamic therapy, photosensitizer

Dual Fenton Catalytic Nanoreactor for Integrative Type-I and Type-II Photodynamic Therapy Against Hypoxic Cancer Cells

2019 ◽  
Vol 2 (9) ◽  
pp. 3854-3860 ◽  
Author(s):  
Xiao Cui ◽  
Jinfeng Zhang ◽  
Yingpeng Wan ◽  
Fang Fang ◽  
Rui Chen ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Cancer Cells ◽  
Type I ◽  
Type Ii

IMPORTANCE OF TYPE I AND TYPE II MECHANISMS IN THE PHOTODYNAMIC INACTIVATION OF VIRUSES IN BLOOD WITH ALUMINUM PHTHALOCYANINE DERIVATIVES

1992 ◽  
Vol 56 (4) ◽  
pp. 463-469 ◽  
Author(s):  
S. Rywkin ◽  
L. Lenny ◽  
J. Goldstein ◽  
N. E. Geacintov ◽  
H. Margolis-Nunno ◽  
...  
Keyword(s):  
Type I ◽  
Photodynamic Inactivation ◽  
Type Ii ◽  
Aluminum Phthalocyanine

scholarly journals Recent Developments in the Synthesis of Pyrido[1,2-a]benzimidazoles

Synthesis ◽  
2018 ◽  
Vol 50 (11) ◽  
pp. 2131-2149 ◽  
Author(s):  
Kamal Kapoor ◽  
Parthasarathi Das ◽  
Rajni Khajuria ◽  
Sk. Rasheed ◽  
Chhavi Khajuria
Keyword(s):  
Transition Metal ◽  
Medicinal Chemistry ◽  
Type I ◽  
Type Ii ◽  
Aromatic Rings ◽  
Metal Free ◽  
Wide Range ◽  
Recent Developments ◽  
Metal Catalyzed ◽  
Synthetic Approaches

Pyrido[1,2-a]benzimidazole is one of the most important azaheterocyclic compounds consisting of three fused aromatic rings. Molecules containing this core have displayed a wide range of applications in the field of medicinal chemistry. The synthesis of pyrido[1,2-a]benzimidazole and its derivatives has attracted organic chemists because of its tremendous utility in interdisciplinary branches of chemistry. In this context, this review discusses the main advances in the synthesis of pyrido[1,2-a]benzimidazoles via metal-mediated and metal-free reactions from 2000 to 2016.1 Introduction2 Synthetic Approaches to Pyrido[1,2-a]benzimidazoles2.1 Type I: Transition-Metal-Catalyzed Methods2.2 Type II: Metal-Free Approaches3 Conclusion

scholarly journals Smart Polymeric Delivery System for Antitumor and Antimicrobial Photodynamic Therapy

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhijia Wang ◽  
Fu-Jian Xu ◽  
Bingran Yu
Keyword(s):  
Photodynamic Therapy ◽  
Bacterial Infections ◽  
Water Solubility ◽  
Polymeric Materials ◽  
Delivery Systems ◽  
Antimicrobial Photodynamic Therapy ◽  
Oxygen Species ◽  
Infection Site ◽  
Polymeric Delivery ◽  
Similarities And Differences

Photodynamic therapy (PDT) has attracted tremendous attention in the antitumor and antimicrobial areas. To enhance the water solubility of photosensitizers and facilitate their accumulation in the tumor/infection site, polymeric materials are frequently explored as delivery systems, which are expected to show target and controllable activation of photosensitizers. This review introduces the smart polymeric delivery systems for the PDT of tumor and bacterial infections. In particular, strategies that are tumor/bacteria targeted or activatable by the tumor/bacteria microenvironment such as enzyme/pH/reactive oxygen species (ROS) are summarized. The similarities and differences of polymeric delivery systems in antitumor and antimicrobial PDT are compared. Finally, the potential challenges and perspectives of those polymeric delivery systems are discussed.

Structural characterization of hexameric shell proteins from two types of choline-utilization bacterial microcompartments

2021 ◽  
Vol 77 (9) ◽  
Author(s):  
Jessica M. Ochoa ◽  
Oscar Mijares ◽  
Andrea A. Acosta ◽  
Xavier Escoto ◽  
Nancy Leon-Rivera ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Building Blocks ◽  
Type I ◽  
Type Ii ◽  
Protein Subunits ◽  
Bacterial Microcompartments ◽  
Bacterial Microcompartment ◽  
Glycyl Radical ◽  
Shell Proteins

Bacterial microcompartments are large supramolecular structures comprising an outer proteinaceous shell that encapsulates various enzymes in order to optimize metabolic processes. The outer shells of bacterial microcompartments are made of several thousand protein subunits, generally forming hexameric building blocks based on the canonical bacterial microcompartment (BMC) domain. Among the diverse metabolic types of bacterial microcompartments, the structures of those that use glycyl radical enzymes to metabolize choline have not been adequately characterized. Here, six structures of hexameric shell proteins from type I and type II choline-utilization microcompartments are reported. Sequence and structure analysis reveals electrostatic surface properties that are shared between the four types of shell proteins described here.

scholarly journals Macular cutaneous amyloidosis treated with methyl aminolevulinate and daylight photodynamic therapy: A case report

2019 ◽  
Vol 7 ◽  
pp. 2050313X1982961
Author(s):  
Christina M Huang ◽  
Lauren Lam ◽  
Robert Gniadecki
Keyword(s):  
Photodynamic Therapy ◽  
Photochemical Reaction ◽  
Therapeutic Option ◽  
Cost Effective ◽  
Oxygen Species ◽  
Type Ii ◽  
Effective Therapeutic Option ◽  
Methyl Aminolevulinate ◽  
Prospective Trials ◽  
The Brain

Primary cutaneous amyloidosis is characterized by polymerization of extracellular amyloid precursors in β-pleated sheet conformation into larger fibrillar aggregates. Observation in models of Alzheimer’s disease have noted that amyloid polymerization in the brain is blocked by reactive oxygen species. Singlet oxygen is formed in the skin during methyl aminolevulinate photodynamic therapy. Therefore, we speculate that type II photochemical reaction is responsible for the observed therapeutic activity of methyl aminolevulinate photodynamic therapy in our patient with primary cutaneous amyloidosis. Our case is the first report demonstrating the efficacy of daylight photodynamic therapy in primary cutaneous amyloidosis. Daylight photodynamic therapy may provide a convenient and cost-effective therapeutic option in primary cutaneous amyloidosis, and its efficacy should be further confirmed in prospective trials.

Nanoscale Metal–Organic Frameworks Stabilize Bacteriochlorins for Type I and Type II Photodynamic Therapy

2020 ◽  
Vol 142 (16) ◽  
pp. 7334-7339 ◽  
Author(s):  
Taokun Luo ◽  
Kaiyuan Ni ◽  
August Culbert ◽  
Guangxu Lan ◽  
Zhe Li ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Metal Organic Frameworks ◽  
Type I ◽  
Type Ii ◽  
Metal Organic

Ground- and excited-state interactions of 2,7,12,17-tetraphenylporphycene with model target biomolecules for type-I photodynamic therapy

2009 ◽  
Vol 13 (01) ◽  
pp. 99-106 ◽  
Author(s):  
Noemí Rubio ◽  
Víctor Martínez-Junza ◽  
Jordi Estruga ◽  
José I. Borrell ◽  
Margarita Mora ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Photodynamic Therapy ◽  
Excited State ◽  
Singlet Oxygen ◽  
Cell Lines ◽  
Mechanism Of Action ◽  
Photophysical Properties ◽  
Type I ◽  
Type Ii ◽  
Hydrophobic Compound

Biosubstrate-sensitizer binding is one of the factors that enhances the type-I mechanism over the type-II in the whole photodynamic process. 2,7,12,17-Tetraphenylporphycene (TPPo), a second-generation photosensitizer, is a hydrophobic compound with good photophysical properties for photodynamic therapy applications that has proved its ability for the photoinactivation of different cell lines. Nevertheless, little is known about its mechanism of action. This paper focuses on the study of the interaction/binding of TPPo with different model biomolecules that may favor the type-I mechanism in the overall photodynamic process, including nucleosides, proteins, and phospholipids. Compared with more hydrophilic photosensitizers, it is concluded that TPPo is more likely to undergo type-II (singlet oxygen) than type-I (electron transfer) photodynamic processes in biological environments.

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