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Coordination Complexes as a New Generation Photosensitizer for Photodynamic Anticancer Therapy.
Pobłocki, K, Drzeżdżon, J, Kostrzewa, T, Jacewicz, D
International journal of molecular sciences. 2021;(15)
Abstract
Photodynamic therapy (PDT) has become an alternative to standard cancer treatment methods such as surgery, chemotherapy and radiotherapy. The uniqueness of this method relies on the possibility of using various photosensitizers (PS) that absorb and convert light emission in radical oxygen-derived species (ROS). They can be present alone or in the presence of other compounds such as metal organic frameworks (MOFs), non-tubules or polymers. The interaction between DNA and metal-based complexes plays a key role in the development of new anti-cancer drugs. The use of coordination compounds in PDT has a significant impact on the amount ROS generated, quantum emission efficiency (Φem) and phototoxic index (PI). In this review, we will attempt to systematically review the recent literature and analyze the coordination complexes used as PS in PDT. Finally, we compared the anticancer activities of individual coordination complexes and discuss future perspectives. So far, only a few articles link so many transition metal ion coordination complexes of varying degrees of oxidation, which is why this review is needed by the scientific community to further expand this field worldwide. Additionally, it serves as a convenient collection of important, up-to-date information.
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2.
Corneal refractive surgery combined with simultaneous corneal cross-linking: Indications, protocols and clinical outcomes-A review.
Ma, J, Wang, Y, Jhanji, V
Clinical & experimental ophthalmology. 2020;(1):78-88
Abstract
Corneal refractive surgery is one of the most common approaches for correction of refractive errors. Combined corneal refractive surgery and corneal cross-linking (CXL) has been proposed as a method to achieve better refractive stability and to prevent iatrogenic corneal ectasia. However, there are concerns regarding its indications, surgical safety, standardization of protocols and long-term effect on corneal tissue. This review article aims to discuss the current knowledge and recent updates on combination of CXL and refractive surgery.
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The odyssey of cobaloximes for catalytic H2 production and their recent revival with enzyme-inspired design.
Dolui, D, Khandelwal, S, Majumder, P, Dutta, A
Chemical communications (Cambridge, England). 2020;(59):8166-8181
Abstract
Cobaloxime complexes gained attention for their intrinsic ability of catalytic H2 production despite their initial emergence as a vitamin B12 model. The simple, robust, and synthetically manoeuvrable cobaloxime core represents a model catalyst molecule for the investigation of optimal conditions for both photo- and electrocatalytic H2 production catalytic assemblies. Cobaloxime is one of the rare catalysts that finds equal applications in the analysis of homogeneous and heterogeneous catalytic conditions. However, the poor aqueous solubility and long-term instability of cobaloximes have severely impeded their growth. Lately, interest in the cobaloxime-based catalysts has been resuscitated with the rational use of extended enzymatic features. This unique enzyme-inspired catalyst design strategy has instigated the formation of a new genre of cobaloxime molecules that exhibit enhanced photo- and electrocatalytic H2 evolution with improved aqueous and air stability.
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4.
Vitamin D and Other Differentiation-promoting Agents as Neoadjuvants for Photodynamic Therapy of Cancer.
Maytin, EV, Hasan, T
Photochemistry and photobiology. 2020;(3):529-538
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Abstract
The efficacy of photodynamic therapy (PDT) using aminolevulinic acid (ALA), which is preferentially taken up by cancerous cells and converted to protoporphyrin IX (PpIX), can be substantially improved by pretreating the tumor cells with vitamin D (Vit D). Vit D is one of several "differentiation-promoting agents" that can promote the preferential accumulation of PpIX within the mitochondria of neoplastic cells, making them better targets for PDT. This article provides a historical overview of how the concept of using combination agents ("neoadjuvants") for PDT evolved, from initial discoveries about neoadjuvant effects of methotrexate and fluorouracil to later studies to determine how vitamin D and other agents actually work to augment PDT efficacy. While this review focuses mainly on skin cancer, it includes a discussion about how these concepts may be applied more broadly toward improving PDT outcomes in other types of cancer.
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5.
Photodynamic Therapy of Psoriasis Using Photosensitizers of Vegetable Origin.
Bruschi, ML, da Silva, JB, Rosseto, HC
Current pharmaceutical design. 2019;(20):2279-2291
Abstract
Psoriasis is an immune-mediated, chronic and recurrent inflammatory skin disease, prevalent worldwide, and represents an important burden in life quality of patients. The most common clinical variant is termed as psoriasis vulgaris or plaque psoriasis, which with an individualized and carefully monitored therapy can decrease the patients' morbidity and improving their life quality. The aim is to achieve disease control, minimize the adverse drug effects, and tailor the treatment to individual patient factors. Photodynamic therapy (PDT) is based on local or systemic administration of a non-toxic photosensitizer followed by irradiation with a particular wavelength to generate reactive oxygen species (ROS), mainly highly cytotoxic singlet oxygen (1O2). The generation of these species results in the attack to substrates involved in biological cycles causing necrosis and apoptosis of affected tissues. Photosensitizers are found in natural products and also obtained by partial syntheses from abundant natural starting compounds. They can be isolated at low cost and in large amounts from plants or algae. Therefore, this manuscript reviews the use of molecules from vegetal sources as photosensitizer agents for the PDT of psoriasis. Psoriasis pathogenesis, management and treatment were reviewed. PDT principles, fundamentals and utilization for the treatment of psoriasis were also discussed. Photosensitizers for PDT of psoriasis are also reviewed focusing on those from vegetal sources. Despite the PDT is utilized for the treatment of psoriasis, very little amount of photosensitizers from plant sources are utilized, such as chlorophyll derivatives and hypericin; however, other natural photosensitizers such as curcumin, could also be investigated. They could constitute a very important, safe and cheap alternative for the successful photodynamic treatment of psoriasis.
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Corneal crosslinking: Current protocols and clinical approach.
Beckman, KA, Gupta, PK, Farid, M, Berdahl, JP, Yeu, E, Ayres, B, Chan, CC, Gomes, JAP, Holland, EJ, Kim, T, et al
Journal of cataract and refractive surgery. 2019;(11):1670-1679
Abstract
Members of the ASCRS Cornea Clinical Committee performed a review of the current literature on the corneal crosslinking (CXL) procedure for treating corneal ectasia. The members explored the data on the techniques currently in use and under investigation, including their advantages, safety profiles, risks, and cost analyses, compared with data on corneal transplantation. They concluded that CXL limits the progression of keratoconus, thus reducing the need for transplantation. They also found that compared with permitting the disease to progress naturally, CXL techniques carry significant and long-term cost and safety benefits, primarily by reducing the need for corneal transplantation. Studies of various CXL techniques (eg, epithelium-on treatment, changes in ultraviolet light parameters, riboflavin composition) continue with the ultimate goal of improving the procedure's safety and efficacy.
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7.
Present and future perspectives of photodynamic therapy for cutaneous squamous cell carcinoma.
Keyal, U, Bhatta, AK, Zhang, G, Wang, XL
Journal of the American Academy of Dermatology. 2019;(3):765-773
Abstract
Cutaneous squamous cell carcinoma (SCC) is the second most common skin cancer. Surgery remains the main stay of treatment, but some patients are not eligible for surgery and, more importantly, lesions at critical sites need nonsurgical approaches for tissue preservation. In this context, photodynamic therapy (PDT) has been extensively studied as noninvasive or minimally invasive treatment, and studies have shown promising results in terms of safety, efficacy, and cosmetic outcome. Also, studies have proposed different mechanism for its efficacy. However, human studies demonstrating its efficacy are limited in terms of sample size and tumor depth of invasion. Good results are mainly seen in case reports of microinvasive SCC, which is defined as SCC limited to papillary dermis. This inadequacy is due to inadequate penetration of topically applied photosensitizers through keratinized tumor surfaces. To overcome these hurdles, pretreatment with lasers or microneedles and encapsulation of photosensitizers into nanoparticles have been tried. Hence, the present article will discuss studies that have demonstrated the efficacy and safety of PDT for cutaneous SCC, studies that have postulated the mechanism of action of PDT, agents that have been used as PDT enhancers, and finally, the recent use of adjuvant therapy in combination with PDT.
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8.
Role of photodynamic therapy in the treatment of esophageal cancer.
Wu, H, Minamide, T, Yano, T
Digestive endoscopy : official journal of the Japan Gastroenterological Endoscopy Society. 2019;(5):508-516
Abstract
Photodynamic therapy (PDT), a treatment of choice for cancer, induces a photochemical reaction, thereby eradicating tumor cells. This is achieved through the administration of a photosensitizer drug, which is activated with a laser after localization to the tumor mass, and is an approved curative endoscopic ablative treatment for superficial esophageal squamous cell carcinoma (ESCC) in Japan. PDT has been approved for dysplastic Barrett's esophagus and as a palliative treatment for patients with symptomatic obstructive esophageal cancer in US. However, its adverse events and complicated procedure and the development of alternative endoscopic procedures such as endoscopic submucosal dissection, radiofrequency ablation and cryotherapy, have largely limited the practice of PDT in esophageal cancer worldwide. Recently, owing to the invention of second-generation PDT using talaporfin sodium and diode laser, PDT can be performed with less phototoxicity and therefore has regained popularity in the treatment of ESCC. As a salvage treatment for patients with local failure after chemoradiotherapy (CRT), PDT has shown promising complete response with less phototoxicity and shorter sun shade period. In addition, the efficacy and safety of PDT in patients with local failure of ESCC after CRT were shown in several clinical trials. The direction of the study interest of the next-generation PDT is the safety and potential expansion of the indications for its application in the future. This review covers the PDT for the treatment of ESCC and dysplastic Barrett's esophagus, with special focus on the role of PDT in practice for esophageal cancer.
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9.
Medical Applications of Rose Bengal- and Riboflavin-Photosensitized Protein Crosslinking.
Redmond, RW, Kochevar, IE
Photochemistry and photobiology. 2019;(5):1097-1115
Abstract
This review summarizes research on many of the potential applications of photosensitized crosslinking of tissue proteins in surgery and current knowledge of the photochemical mechanisms underlying formation of the covalent protein-protein crosslinks involved. Initially developed to close wounds or reattach tissues, protein photocrosslinking has also been demonstrated to stiffen and strengthen tissues, decrease inflammatory responses and facilitate tissue bioengineering. These treatments appear to result largely from crosslinks within and between collagen molecules in tissue that typically form by an oxygen-dependent mechanism. Surgical applications discussed include sealing wounds in skin, cornea and bowel; reattaching severed nerves, blood vessels and tendons; strengthening cornea and vein; reducing capsular contracture after breast implants; and regenerating joint cartilage.
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10.
Corneal Cross-Linking: The Science Beyond the Myths and Misconceptions.
Rubinfeld, RS, Caruso, C, Ostacolo, C
Cornea. 2019;(6):780-790
Abstract
PURPOSE There has been a recent explosion in the variety of techniques used to accomplish corneal cross-linking (CXL) for the treatment of ectatic corneal diseases. To understand the success or failure of various techniques, we review the physicochemical basis of corneal CXL and re-evaluate the current principles and long-standing conventional wisdom in the light of recent, compelling, and sometimes contradictory research. METHODS Two clinicians and a medicinal chemist developed a list of current key topics, controversies, and questions in the field of corneal CXL based on information from current literature, medical conferences, and discussions with international practitioners of CXL. RESULTS Standard corneal CXL with removal of the corneal epithelium is a safe and efficacious procedure for the treatment of corneal ectasias. However, the necessity of epithelium removal is painful for patients, involves risk and requires significant recovery time. Attempts to move to transepithelial corneal CXL have been hindered by the lack of a coherent understanding of the physicochemistry of corneal CXL. Misconceptions about the applicability of the Bunsen-Roscoe law of reciprocity and the Lambert-Beer law in CXL hamper the ability to predict the effect of ultraviolet A energy during CXL. Improved understanding of CXL may also expand the treatment group for corneal ectasia to those with thinner corneas. Finally, it is essential to understand the role of oxygen in successful CXL. CONCLUSIONS Improved understanding of the complex interactions of riboflavin, ultraviolet A energy and oxygen in corneal CXL may provide a successful route to transepithelial corneal CXL.