ABSTRACT
Facing a 40% mortality rate in candidemia patients, drug-resistant Candida and their petite mutants remain a major treatment challenge. Antimicrobial photodynamic therapy (aPDT) targets multiple fungal structures, unlike antibiotics/antifungals, potentially thwarting resistance. Traditional methods for inducing petite colonies rely on ethidium bromide or fluconazole, which can influence drug susceptibility and stress responses. This study investigated the application of green light (peak 520 nm) and rose bengal (RB) photosensitizer to combat a drug-resistant Candida glabrata isolate. The findings revealed that aPDT treatment significantly inhibited cell growth (≥99.9% reduction) and effectively induced petite colony formation, as evidenced by reduced size and loss of mitochondrial redox indicator staining. This study provides initial evidence that aPDT can induce petite colonies in a multidrug-resistant C. glabrata strain in vitro, offering a potentially transformative approach for combating resistant fungal infections.
Subject(s)
Candida , Photochemotherapy , Humans , Rose Bengal/pharmacology , Candida glabrata , Photosensitizing Agents/pharmacologyABSTRACT
Sepsis is a life-threatening condition, which is irreversible if diagnosis and intervention are delayed. The response of the immune cells towards an infection triggers widespread inflammation through the production of cytokines, which may result in multiple organ dysfunction and eventual death. Conventional detection techniques fail to provide a rapid diagnosis because of their limited sensitivity and tedious protocol. This study proposes a point-of-care (POC) electrochemical biosensor that overcomes the limitations of current biosensing technologies in the clinical setting by its integration with electrokinetics, enhancing the sensitivity to picogram level compared with the nanogram limit of current diagnostic technologies. This biosensor promotes the use of a microelectrode strip to address the limitations of conventional photolithographic fabrication methods. Tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and microRNA-155 (miR-155) were monitored in a lipopolysaccharide (LPS)-induced septic mouse model. The optimum target hybridization time in a high conductivity medium was observed to be 60 s leading to the completion of the whole operation within 5 min compared with the 4-h detection time of the traditional enzyme-linked immunosorbent assay (ELISA). The limit of detection (LOD) was calculated to be 0.84, 0.18, and 0.0014 pg mL-1, respectively. This novel sensor may have potential for the early diagnosis of sepsis in the clinical setting.
Subject(s)
Biosensing Techniques , MicroRNAs , Sepsis , Mice , Animals , Lipopolysaccharides/toxicity , Point-of-Care Systems , Disease Models, Animal , Biosensing Techniques/methods , Sepsis/chemically induced , Sepsis/diagnosis , Biomarkers/analysis , Tumor Necrosis Factor-alpha , MicroRNAs/analysisABSTRACT
Enterovirus A71 (EV-A71) infection typically causes mild illnesses, such as hand-foot-and-mouth disease (HFMD), but occasionally leads to severe or fatal neurological complications in infants and young children. Currently, there is no specific antiviral treatment available for EV-A71 infection. Thus, the development of an effective anti-EV-A71 drug is required urgently. Cordycepin, a major bioactive compound found in Cordyceps fungus, has been reported to possess antiviral activity. However, its specific activity against EV-A71 is unknown. In this study, the potency and role of cordycepin treatment on EV-A71 infection were investigated. Results demonstrated that cordycepin treatment significantly reduced the viral load and viral ribonucleic acid (RNA) level in EV-A71-infected Vero cells. In addition, EV-A71-mediated cytotoxicity was significantly inhibited in the presence of cordycepin in a dose-dependent manner. The protective effect can also be extended to Caco-2 intestinal cells, as evidenced by the higher median tissue culture infectious dose (TCID50) values in the cordycepin-treated groups. Furthermore, cordycepin inhibited EV-A71 replication by acting on the adenosine pathway at the post-infection stage. Taken together, our findings reveal that cordycepin could be a potential antiviral candidate for the treatment of EV-A71 infection.
Subject(s)
Deoxyadenosines , Enterovirus A, Human , Enterovirus Infections , Enterovirus , Hand, Foot and Mouth Disease , Animals , Chlorocebus aethiops , Infant , Child , Humans , Child, Preschool , Enterovirus A, Human/genetics , Vero Cells , Adenosine/pharmacology , Caco-2 Cells , Virus Replication , Enterovirus Infections/drug therapy , Antigens, Viral , Antiviral Agents/pharmacologyABSTRACT
Nonantibiotic approaches must be developed to kill pathogenic bacteria and ensure that clinicians have a means to treat wounds that are infected by multidrug-resistant bacteria. This study prepared matchstick-like Ag2S-ZnS heteronanostructures (HNSs). Their hydrophobic surfactants were then replaced with hydrophilic poly(ethylene glycol) (PEG) and thioglycolic acid (TGA) through the ligand exchange method, and this was followed by ascorbic acid (AA) conjugation with TGA through esterification, yielding well-dispersed PEGylated Ag2S-ZnS@TGA-AA HNSs. The ZnS component of the HNSs has innate semiconductivity, enabling the generation of electron-hole pairs upon irradiation with a light of wavelength 320 nm. These separate charges can react with oxygen and water around the HNSs to produce reactive oxygen species. Moreover, some holes can oxidize the surface-grafted AA to produce protons, decreasing the local pH and resulting in the corrosion of Ag2S, which releases silver ions. In evaluation tests, the PEGylated Ag2S-ZnS@TGA-AA had synergistic antibacterial ability and inhibited Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus (MRSA). Additionally, MRSA-infected wounds treated with a single dose of PEGylated Ag2S-ZnS@TGA-AA HNSs under light exposure healed significantly more quickly than those not treated, a result attributable to the HNSs' excellent antibacterial and Bohr effects.
Subject(s)
Methicillin-Resistant Staphylococcus aureus , Wound Infection , Humans , Anti-Bacterial Agents/pharmacology , Wound Healing , Polyethylene Glycols/pharmacology , Hydrogen-Ion ConcentrationABSTRACT
BACKGROUND: Previous studies have confirmed the expression of tissue inhibitor of metalloproteinase-3 (TIMP3) in Müller glia (MG). However, the role of TIMP3 in MG remains unknown. METHODS: A mouse model of laser-induced retinal damage and gliosis was generated using wild-type C57BL/6 mice. TIMP3 and associated proteins were detected using Western blotting and immunofluorescence microscopy. RNA sequencing (GSE132140) of mouse laser-induced gliosis was utilized for pathway analysis. TIMP3 overexpression was induced in human MG. Human vitreous samples were obtained from patients with proliferative diabetic retinopathy (PDR) and healthy controls for protein analysis. RESULTS: TIMP3 levels increased in mouse eyes after laser damage. Morphology and spatial location of TIMP3 indicated its presence in MG. TIMP3-overexpressing MG showed increased cellular proliferation, migration, and cell nuclei size, suggesting TIMP3-induced gliosis for retinal repair. Glial fibrillary acidic protein (GFAP) and vimentin levels were elevated in TIMP3-overexpressing MG and laser-damaged mouse retinas. RNA sequencing and Western blotting suggested a role for ß-catenin in mediating TIMP3 effects on the retina. Human vitreous samples from patients with PDR showed a positive correlation between TIMP3 and GFAP levels, both of which were elevated in patients with PDR. CONCLUSIONS: TIMP3 is associated with MG gliosis to enhance the repair ability of damaged retinas and is mediated by the canonical Wnt/ß-catenin. Changes in TIMP3 could potentially be used to control gliosis in a range of retinal diseases However, given the multifaceted nature of TIMP3, care must be taken when developing treatments that aim solely to boost the function of TIMP3. FUNDING: National Cheng Kung University Hospital, Taiwan (NCKUH-10604009 and NCKUH-11202007); the Ministry of Science and Technology (MOST 110-2314-B-006-086-MY3).
Subject(s)
Diabetic Retinopathy , Retinal Diseases , Animals , Humans , Mice , beta Catenin/genetics , beta Catenin/metabolism , Diabetic Retinopathy/metabolism , Gliosis/metabolism , Mice, Inbred C57BL , Neuroglia/metabolism , Retina/metabolism , Retinal Diseases/metabolism , Tissue Inhibitor of Metalloproteinase-3/genetics , Tissue Inhibitor of Metalloproteinase-3/metabolismABSTRACT
Introduction: In East Asia, more than half of patients with amyopathic dermatomyositis (ADM) have interstitial lung disease (ILD). There is up to 50% 6-month mortality in MDA5-positive ILD refractory to corticosteroid (CS) combined with immunosuppressant therapy. Patient Details: A 39-year-old local woman had a 1-month history of reddish-purple discoloration around the eyelids (heliotrope rash), and erythematous areas on the upper back and posterior neck (shawl sign) as well as on the front of her chest (V sign), followed by dry cough and mild dyspnea for 1 week. She had normal muscle strength, muscle-enzyme concentrations, and muscular magnetic resonance images. Laboratory tests showed hypoxemia, increased ferritin and CRP levels, and positive MDA5 antibodies. High-resolution chest computed tomography revealed bilateral ground-glass opacity. She received a diagnosis of anti-MDA5-positive ADM with early-stage ILD. Intervention: Pulse methylprednisolone and cyclophosphamide therapies were initiated, followed by high-dose CS treatment. Immediate-release twice-daily 5 mg tofacitinib (Tof) has been demonstrated to be effective induction therapy for early-stage ILD in anti-MDA5-positive ADM. Owing to the patient's preference for once-daily therapy, 11 mg extended-release Tof was prescribed 4 weeks after starting the initial pulse CS treatment for ILD. Outcomes: Respiratory symptoms and cutaneous manifestations were absent and the use of CS spared 5 months after initiating Tof therapy. Laboratory examinations exhibited normalized ferritin/oxygen levels, and chest images displayed completely resolved pulmonary infiltration. ILD remains under adequate control with Tof monotherapy without recurrence at 5 months. Lessons: Owing to a rapid decline in higher mortality in anti-MDA5-positive ADM patients with ILD, early detection with prompt initiation of extended-release Tof induction therapy might achieve a beneficial outcome.
Subject(s)
Cryosurgery , Melanoma , Skin Neoplasms , Humans , Disease-Free Survival , Melanoma, Cutaneous MalignantABSTRACT
Primary cutaneous lymphomas are rare non-Hodgkin lymphomas consisting of heterogeneous disease entities. Photodynamic therapy (PDT) utilizing photosensitizers irradiated with a specific wavelength of light in the presence of oxygen exerts promising anti-tumor effects on non-melanoma skin cancer, yet its application in primary cutaneous lymphomas remains less recognized. Despite many in vitro data showing PDT could effectively kill lymphoma cells, clinical evidence of PDT against primary cutaneous lymphomas is limited. Recently, a phase 3 "FLASH" randomized clinical trial demonstrated the efficacy of topical hypericin PDT for early-stage cutaneous T-cell lymphoma. An update on recent advances of photodynamic therapy in primary cutaneous lymphomas is provided.
ABSTRACT
BACKGROUND: Melanoma is a highly aggressive tumor and a significant cause of skin cancer-related death. Timely diagnosis and treatment require identification of specific biomarkers in exosomes secreted by melanoma cells. In this study, label-free surface-enhanced Raman spectroscopy (SERS) method with size-matched selectivity was used to detect membrane proteins in exosomes released from a stimulated environment of fibroblasts (L929) co-cultured with melanoma cells (B16-F10). To promote normal secretion of exosomes, micro-plasma treatment was used to gently induce the co-cultured cells and slightly increase the stress level around the cells for subsequent detection using the SERS method. RESULTS AND DISCUSSION: Firstly, changes in reactive oxygen species/reactive nitrogen species (ROS/RNS) concentrations in the cellular microenvironment and the viability and proliferation of healthy cells are assessed. Results showed that micro-plasma treatment increased extracellular ROS/RNS levels while modestly reducing cell proliferation without significantly affecting cell survival. Secondly, the particle size of secreted exosomes isolated from the culture medium of L929, B16-F10, and co-cultured cells with different micro-plasma treatment time did not increase significantly under single-cell conditions at short treatment time but might be changed under co-culture condition or longer treatment time. Third, for SERS signals related to membrane protein biomarkers, exosome markers CD9, CD63, and CD81 can be assigned to significant Raman shifts in the range of 943-1030 and 1304-1561 cm-1, while the characteristics SERS peaks of L929 and B16-F10 cells are most likely located at 1394/1404, 1271 and 1592 cm-1 respectively. SIGNIFICANCE AND NOVELTY: Therefore, this micro-plasma-induced co-culture model provides a promising preclinical approach to understand the diagnostic potential of exosomes secreted by cutaneous melanoma/fibroblasts. Furthermore, the label-free SERS method with size-matched selectivity provides a novel approach to screen biomarkers in exosomes secreted by melanoma cells, aiming to reduce the use of labeling reagents and the processing time traditionally required.
Subject(s)
Coculture Techniques , Exosomes , Fibroblasts , Spectrum Analysis, Raman , Exosomes/metabolism , Exosomes/chemistry , Fibroblasts/metabolism , Fibroblasts/cytology , Mice , Animals , Spectrum Analysis, Raman/methods , Plasma Gases/chemistry , Plasma Gases/pharmacology , Reactive Oxygen Species/metabolism , Cell Proliferation , Melanoma/metabolism , Melanoma/pathology , Cell SurvivalABSTRACT
Patent ductus arteriosus (PDA) is a common cardiovascular complication that complicates clinical care in the intensive care of premature infants. Prenatal and postnatal infections and the inflammation process can contribute to PDA, and intrauterine inflammation is a known risk factor of PDA. A variety of inflammatory biomarkers have been reported to be associated with PDA. Chorioamnionitis induces the fetal inflammatory process via several cytokines that have been reported to be associated with the presence of PDA and may have a role in the vascular remodeling process or vessel dilation of the ductus. On the other hand, anti-inflammatory agents, such as antenatal steroids, decrease PDA incidence and severity in patients born to those with chorioamnionitis. Proinflammatory cytokines, which are expressed more significantly in preterm neonates and chorioamnionitis, are associated with the presence of PDA. In this review, we focus on the pathogenesis of PDA in preterm infants and the role of biomarkers associated with the perinatal inflammatory process.
Subject(s)
Chorioamnionitis , Ductus Arteriosus, Patent , Infant, Premature, Diseases , Infant , Humans , Infant, Newborn , Female , Pregnancy , Ductus Arteriosus, Patent/pathology , Infant, Premature , Biomarkers , Inflammation/complications , CytokinesABSTRACT
Multiple large lesions of Bowen's disease (BD) often appear in patients who have been under chronic exposure to arsenic. The treatment of such lesions is very challenging. Photodynamic therapy (PDT) has been considered a first-line effective treatment for BD. However, lesions larger than 2 cm are less responsive to PDT. We reported two giant BD lesions (> 10 cm in diameter), that were on a chronic arsenicosis patient's back, to be successfully treated with PDT and subsequent imiquimod occlusion overnight twice a week on the week after PDT. No recurrence was noted during the 12-month follow-up.
Subject(s)
Bowen's Disease , Photochemotherapy , Skin Neoplasms , Humans , Bowen's Disease/pathology , Photochemotherapy/methods , Aminolevulinic Acid/therapeutic use , Imiquimod/therapeutic use , Photosensitizing Agents/therapeutic use , Skin Neoplasms/drug therapy , Skin Neoplasms/pathology , Treatment OutcomeABSTRACT
BACKGROUND: Lysosomal cell death is induced by lysosomal membrane permeabilization (LMP) and the subsequent release of lysosomal proteolytic enzymes, including cathepsins (CTSs), which results in mitochondrial dysfunction and apoptosis. Imiquimod (IMQ), a synthetic TLR7 ligand, has both antiviral and antitumor activity against various skin malignancies in clinical treatment. Previously, we demonstrated IMQ not only caused lysosomal dysfunction but also triggered lysosome biogenesis to achieve lysosomal adaptation in cancer cells. OBJECTIVE: To determine whether lysosomes are involved in IMQ-induced apoptosis. METHODS: The human skin cancer cell lines BCC, A375 and mouse melanoma cell line B16F10 were used in all experiments. Cell death was determined by the Cell Counting Kit-8 (CCK-8) assay and DNA content assay. Protein expression was determined by immunoblotting. Caspase-8 activity was assessed using a fluorescence caspase-8 kit and determined by flow cytometry and confocal microscopy. RESULTS: IMQ not only induced lysosome damage but also abrogated lysosome function in skin cancer cells. IMQ-induced caspase-8 activation contributed to the processes of lysosomal cell death. Moreover, the use of ROS scavengers significantly abolished caspase-8 activation and inhibited IMQ-induced LMP. Additionally, pharmacological inhibition of CTSD not only abrogated caspase-8 activation but also rescued IMQ-induced cell death. Finally, lysosome-alkalizing agents enhanced the cytotoxicity of IMQ in vitro and in vivo. CONCLUSIONS: IMQ-induced ROS accumulation promotes LMP, releases CTSs into the cytosol, stimulates caspase-8 activation and finally causes lysosomal cell death. Lysosomal cell death and the CTSD/caspase-8 axis may play a crucial role in IMQ-induced cell death.
Subject(s)
Skin Neoplasms , Toll-Like Receptor 7 , Animals , Antiviral Agents/therapeutic use , Apoptosis , Caspase 8/metabolism , Caspase 8/pharmacology , Caspase 8/therapeutic use , Cathepsins/metabolism , Cathepsins/pharmacology , Cathepsins/therapeutic use , DNA/metabolism , Humans , Imiquimod/pharmacology , Ligands , Lysosomes/metabolism , Mice , Reactive Oxygen Species/metabolism , Signal Transduction , Skin Neoplasms/drug therapy , Skin Neoplasms/metabolism , Toll-Like Receptor 7/metabolismABSTRACT
RATIONALE: Although single-cytokine inhibitors can be considered in treating severe or refractory Behçet disease (BD), these biologic agents are associated with potential therapeutic failure due to the multi-cytokine pathogenesis involving Th1- and Th17-type cytokines with activated Janus kinase/signal transducer and activator of transcription signaling pathways. Notably, there is an increasing trend toward the use of small-molecule targeted drug tofacitinib (TOF), a pan-Janus kinase inhibitor, with immediate-release formulations for treating patients with severe or refractory systemic vasculitis involving different vessel sizes. Despite no reported efficacy of extended-release formulations in refractory BD yet, such a dosage form has pharmacokinetic parameters that are comparable to those of conventional immediate-release formulations. PATIENT CONCERNS AND DIAGNOSIS: We report the case of a 27-year-old local woman with recurrent manifestations of arthritis, orogential ulcerations, papulopustular lesions, and anterior uveitis. She was diagnosed with BD for more than 3 years, and received long-term corticosteroids plus immunosuppressants therapy with the complication of opportunistic candidiasis infection. INTERVENTIONS AND OUTCOMES: Under extended-release TOF 11âmg once-daily therapy, the patient achieved disease remission while sparing the use of corticosteroids during follow-up. LESSONS: Our clinical observations implicate the oral convenience and therapeutic efficacy of extended-release TOF formulations in controlling the disease activity of BD.
Subject(s)
Behcet Syndrome , Adrenal Cortex Hormones/therapeutic use , Adult , Behcet Syndrome/complications , Cytokines , Delayed-Action Preparations , Female , Humans , Piperidines , PyrimidinesABSTRACT
Invasive Candida albicans infection is a significant opportunistic fungal infection in humans because it is one of the most common colonizers of the gut, mouth, vagina, and skin. Despite the availability of antifungal medication, the mortality rate of invasive candidiasis remains ~50%. Unfortunately, the incidence of drug-resistant C. albicans is increasing globally. Antimicrobial photodynamic therapy (aPDT) may offer an alternative or adjuvant treatment to inhibit C. albicans biofilm formation and overcome drug resistance. Rose bengal (RB)-mediated aPDT has shown effective cell killing of bacteria and C. albicans. In this study, the efficacy of RB-aPDT on multidrug-resistant C. albicans is described. A homemade green light-emitting diode (LED) light source is designed to align with the center of a well of a 96-well plate. The yeasts were incubated in the wells with different concentrations of RB and illuminated with varying fluences of green light. The killing effects were analyzed by the plate dilution method. With an optimal combination of light and RB, 3-log growth inhibition was achieved. It was concluded that RB-aPDT might potentially inhibit drug-resistant C. albicans.
Subject(s)
Anti-Infective Agents , Photochemotherapy , Anti-Bacterial Agents/pharmacology , Anti-Infective Agents/pharmacology , Antifungal Agents/pharmacology , Biofilms , Candida albicans/physiology , Candidiasis , Female , Humans , Photochemotherapy/methods , Photosensitizing Agents/pharmacology , Rose Bengal/pharmacologyABSTRACT
Photodermatosis is an abnormal skin inflammatory reaction to light. The major classifications of photodermatoses are idiopathic photodermatoses, photodermatoses due to exogenous or endogenous agents, photo-exacerbated dermatoses, and photosensitive genodermatoses. In this chapter, we focus on idiopathic photodermatoses and drug-related photodermatoses and emphasize on the epidemiology and immunogenetic backgrounds. Idiopathic photodermatoses, a spectrum of diseases with abnormal responses to ultraviolet radiation (UVR), include polymorphous light eruption, actinic prurigo, hydroa vacciniforme, chronic actinic dermatitis, and solar urticaria. Young people are more susceptible to most idiopathic photodermatoses except for chronic actinic dermatitis. Interestingly, idiopathic photodermatoses exhibit different characteristics between Caucasians and Asians. For example, the average age of Asian actinic prurigo patients is older than that of Caucasians in which genetic backgrounds or Fitzpatrick skin type might play a role. Drug-induced photodermatoses can be classified into phototoxic and photoallergic drug reactions. Certain drug-induced photodermatoses may mimic other dermatoses. For instance, drug-induced lupus erythematosus (LE) should be considered if an old man is diagnosed with LE but had a poor response to standard treatments.
Subject(s)
Photosensitivity Disorders , Ultraviolet Rays , Adolescent , Humans , Immunogenetics , Male , Photosensitivity Disorders/diagnosis , Photosensitivity Disorders/genetics , Ultraviolet Rays/adverse effectsABSTRACT
Photodynamic therapy (PDT) has become the first-line treatment of actinic keratosis, superficial basal cell carcinoma, and squamous cell carcinoma in situ (Bowen's disease) in dermatology. The off-label use of PDT has also escalated in recent years owing to its applications in the treatment of various non-neoplastic skin diseases such as acne vulgaris, vascular lesions, rejuvenation, and chronic wounds. Daylight PDT that uses natural sunlight to activate a photosensitizer with advantages such as low cost and reduced pain is widely used in Europe. This chapter reviews the applications and immunogenetic aspects of PDT. However, the studies of immunity and genetic changes in human tissue after PDT are limited.
Subject(s)
Keratosis, Actinic , Photochemotherapy , Skin Neoplasms , Humans , Immunogenetics , Keratosis, Actinic/drug therapy , Photosensitizing Agents/therapeutic use , Skin Neoplasms/drug therapyABSTRACT
Traditional immunosensors are often limited by low sensitivity and long detection times, for they usually depend on passive diffusion-dominated transport of target analytes for the binding reaction with a bio-recognition element such as enzymes, antibodies, and aptamers. Numerous studies rely on electric field manipulation by using alternating current (AC) electrokinetics to enhance the hybridization rate and reduce the hybridization time for faster and more efficient detection. This study demonstrated a rapid electrochemical aptasensor integrated with an AC electroosmotic (ACEO) flow phenomenon for the enhanced target hybridization of microRNA-155 (miR-155). Optimization of the electrokinetic conditions for target collection resulted in a saturation point after 75 s miR-155 was detected within the range of 1 aM-10 pM with a detection limit of 1 aM, which is 100 times lower and about 50 times faster compared with the conventional diffusion-dependent detection done for 1 h. The detection was also done in spiked serum samples, and a concentration range within the required detection range was obtained. The highly sensitive and specific results allow for the rapid and real-time sensing of target biomarkers, which can be used for the early detection of infection.
Subject(s)
Aptamers, Nucleotide , Biosensing Techniques , MicroRNAs , Electrochemical Techniques , Electroosmosis , Immunoassay , Limit of Detection , Nucleic Acid HybridizationABSTRACT
Doxycycline hyclate (DCH) and minocycline hydrochloride (MH) are tetracycline antibiotics and broad-spectrum antimicrobial agents. The changes in DCH and MH under blue light (λ = 462 nm) irradiation in alkaline conditions (BLIA) were investigated. Deactivation caused by superoxide anion radical (O2â¢-) and deactivation from DCH and MH during photolysis on Staphylococcus aureus (S. aureus), including methicillin-resistant S. aureus (MRSA), were studied. DCH is relatively unstable compared to MH under BLIA. The level of O2â¢- generated from the MH-treated photoreaction is lower than that from DCH photolysis, and the DCH-treated photoreaction is more efficient at inactivating S. aureus and MRSA at the same radiant intensity. DCH subjected to BLIA decreased the viability of S. aureus and MRSA by 3.84 and 5.15 log, respectively. Two photolytic products of DCH (PPDs) were generated under BLIA. The mass spectra of the PPDs featured molecular ions at m/z 460.8 and 458.8. The molecular formulas of the PPDs were C21H22N2O10 and C22H24N2O9, and their exact masses were 462.44 and 460.44 g/mol, respectively. These results bolster the photolytic oxidation that leads to DCH-enhanced deactivation of S. aureus and MRSA. Photochemical treatment of DCH could be applied as a supplement in hygienic processes.
Subject(s)
Staphylococcus aureusABSTRACT
Fungal keratitis is a serious clinical infection on the cornea caused by fungi and is one of the leading causes of blindness in Asian countries. The treatment options are currently limited to a few antifungal agents. With the increasing incidence of drug-resistant infections, many patients fail to respond to antibiotics. Riboflavin-mediated corneal crosslinking (similar to photodynamic therapy (PDT)) for corneal ectasia was approved in the US in the early 2000s. Current evidence suggests that PDT could have the potential to inhibit fungal biofilm formation and overcome drug resistance by using riboflavin and rose bengal as photosensitizers. However, only a few clinical trials have been initiated in anti-fungal keratitis PDT treatment. Moreover, the removal of the corneal epithelium and repeated application of riboflavin and rose bengal are required to improve drug penetration before and during PDT. Thus, an improvement in trans-corneal drug delivery is mandatory for a successful and efficient treatment. In this article, we review the studies published to date using PDT against fungal keratitis and aim to enhance the understanding and awareness of this research area. The potential of modifying photosensitizers using nanotechnology to improve the efficacy of PDT on fungal keratitis is also briefly reviewed.