Displaying publications 1 - 20 of 47 in total

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  1. Tan KF, In LLA, Vijayaraj Kumar P
    ACS Appl Bio Mater, 2023 Aug 21;6(8):2944-2981.
    PMID: 37435615 DOI: 10.1021/acsabm.3c00202
    Gold nanoparticles (AuNPs) have undergone significant research for their use in the treatment of cancer. Numerous researchers have established their potent antitumor properties, which have greatly impacted the treatment of cancer. AuNPs have been used in four primary anticancer treatment modalities, namely radiation, photothermal therapy, photodynamic therapy, and chemotherapy. However, the ability of AuNPs to destroy cancer is lacking and can even harm healthy cells without the right direction to transport them to the tumor microenvironment. Consequently, a suitable targeting technique is needed. Based on the distinct features of the human tumor microenvironment, this review discusses four different targeting strategies that target the four key features of the tumor microenvironment, including abnormal vasculature, overexpression of specific receptors, an acidic microenvironment, and a hypoxic microenvironment, to direct surface-functionalized AuNPs to the tumor microenvironment and increase antitumor efficacies. In addition, some current completed or ongoing clinical trials of AuNPs will also be discussed below to further reinforce the concept of using AuNPs in anticancer therapy.
    Matched MeSH terms: Photochemotherapy*
  2. Al-Maweri SA, Alhajj MN, Anweigi L, Ashraf S, Halboub E, Salleh NM, et al.
    BMC Oral Health, 2024 Jan 16;24(1):84.
    PMID: 38229054 DOI: 10.1186/s12903-023-03789-z
    BACKGROUND: Photodynamic therapy (PDT) has been recently proposed as a promising alternative therapy for Denture Stomatitis (DS). The present systematic review and meta-analysis investigated the current available evidence regarding the efficacy of PDT in the management of DS.

    MATERIALS AND METHODS: PubMed, Scopus, Web of Science, Google Scholar, and ProQuest were searched up to June 7, 2023. All relevant clinical trials were included. RevMan software was used for the statistical analyses.

    RESULTS: Elven randomized clinical trials (460 DS patients) were included. Eight studies assessed the efficacy of PDT vs. topical antifungal therapy, while three studies assessed the adjunctive use of PDT (PDT + antifungal therapy) vs. topical antifungal therapy alone. The results revealed comparable efficacy of PDT and conventional antifungal therapy on candida colonization at 15 days (MD: 0.95, 95% CI: -0.28, 2.19, p = 0.13) and at the end of follow-up (MD: -0.17, 95% CI: -1.33, 0.98, p = 0.77). The pooled two studies revealed relatively better efficacy of adjunctive use of PDT with antifungal therapy on candida colonization compared to antifungal therapy alone at 15 days (MD: -6.67, 95% CI: -15.15, 1.82, p = 0.12), and at the end of follow-up (MD: -7.14, 95% CI: -19.78, 5.50, p = 0.27). Additionally, the results revealed comparable efficacy of PDT and topical antifungal therapy on the clinical outcomes.

    CONCLUSIONS: PDT might be considered a viable option for DS either as an adjunct or as an alternative to the topical antifungal medications. Further studies with adequate sample sizes and standardized PDT parameters are warranted.

    Matched MeSH terms: Photochemotherapy*
  3. Kue CS, Ng SY, Voon SH, Kamkaew A, Chung LY, Kiew LV, et al.
    Photochem Photobiol Sci, 2018 Nov 01;17(11):1691-1708.
    PMID: 29845993 DOI: 10.1039/c8pp00113h
    BODIPYs are photosensitizers activatable by light to generate highly reactive singlet oxygen (1O2) from molecular oxygen, leading to tissue damage in the photoirradiated region. Despite their extraordinary photophysical characteristics, they are not featured in clinical photodynamic therapy. This review discusses the recent advances in the design and/or modifications of BODIPYs since 2013, to improve their potential in photodynamic cancer therapy and related areas.
    Matched MeSH terms: Photochemotherapy
  4. Ghoshal R, Sharanjeet-Kaur S, Fadzil NM, Ghosh S, Ngah NF, Aziz RABA
    PMID: 33806713 DOI: 10.3390/ijerph18052581
    The objective of this study was to compare visual parameters and retinal layers' morphology pre-treatment (baseline) and 6 months post-treatment in polypoidal choroidal vasculopathy (PCV) eyes. A single centre, longitudinal, prospective study was conducted at a public tertiary hospital of Malaysia. Visual parameters including distance and near visual acuity (DVA and NVA), contrast sensitivity (CS), reading speed (RS), and different qualitative and quantitative optical coherence tomography (OCT) parameters were evaluated pre- and 6 months post-treatment. Thirty-three naïve PCV eyes of 32 patients (mean age of 67.62 years) were evaluated pre- and post-treatment of intravitreal ranibizumab with and without photodynamic therapy. After treatment, sub retinal fluid decreased from 27 eyes (84.35%) at baseline to 7 eyes (21.88%) at 6 months while pigment epithelium detachment decreased from 32 eyes (100%) at base line to 15 eyes (46.87%) at 6 months. Mean pre-treatment quantitative morphological OCT retinal parameters including thickness and volume of central sub field, center thickness, center minimum, and maximum thickness reduced significantly. Similarly, all visual parameters including DVA, NVA, CS, and RS showed statistically significant improvement. While 89% of the eyes showed improvement in CS, 78%, 71%, and 65% of the eyes showed improvement in NVA, RS, and DVA, respectively. Thus, CS was the most treatment responsive visual parameter.
    Matched MeSH terms: Photochemotherapy*
  5. Qamar Z, Alhaid ASM, Altami RM, Bachat AMW, Aldosseri DMS
    Eur Rev Med Pharmacol Sci, 2022 Dec;26(24):9480-9488.
    PMID: 36591857 DOI: 10.26355/eurrev_202212_30700
    OBJECTIVE: The aim of the study is to evaluate the awareness, comportment and attitude/perception of dentists regarding the use of photodynamic (PD) therapy before and during COVID-19 pandemic around the globe.

    SUBJECTS AND METHODS: An online survey was performed by sending out an online questionnaire comprising 21 questions among dental practitioners working in four different countries: Saudi Arabia, Pakistan, Malaysia and United Kingdom. The survey evaluated dental practitioners' level of awareness about the PD therapy, comportment and attitude for its implication and prevalence in daily clinical practice. For statistical significance the Chi-square analysis with Spearman Correlation coefficient was conducted to assess the sub-groups and correlating the factors with the level of awareness of the dental practitioners.

    RESULTS: A total of 1,219 dental practitioners from four different countries (Saudi Arabia, Pakistan, Malaysia and United Kingdom) responded to the questionnaire. The median age of the respondents was 37, 34, 36 and 39 respectively. The majority of dental practitioners demonstrated to have an acceptable level of awareness regarding PD therapy. Nearly 76%, 74%, 79% and 80% of the individuals from Saudi Arabia, Pakistan, Malaysia and United Kingdom respectively were aware of the role/mechanism of action of the PD therapy. Moreover, in preponderance, practitioners were confident that the effect of PD therapy will not be reduced in patients infected with COVID-19. The majority of dental practitioners were convinced that successful dental treatment due to PD therapy is linked majorly with therapies done in relation to four major dental specialties: prosthodontics, endodontic, restorative dentistry and periodontology. Approximately more than 90% of the dentists were sure that the rate of COVID-19 transmission can be reduced by using PD therapy in oral treatments. The dental practitioners from Saudi Arabia (91%), Pakistan (82%), Malaysia (83%) and United Kingdom (82%) were contented to learn about PD therapy for its use in clinical practice. Nearly more than 95% of the practitioners from the four countries were keen to attend the lectures/hands-on workshops regarding PD therapy to enhance their skills and knowledge. More than 80% of dentists do not refuse the peripheral role of PD therapy with their patients.

    CONCLUSIONS: The respondents from the four countries displayed passable level of awareness regarding basic information of PD therapy and its clinical implication in dental specialty. Nevertheless, there is a need to develop awareness regarding the use of PD therapy among dental practitioners during their undergraduate program. Furthermore, lectures and hands-on workshops should be arranged to train dental practitioners in order to enhance their skills for its solicitation in clinical practice. It is perceived by the dentists in the four countries that the use of PD therapy can effectively reduce COVID-19 rate of transmission.

    Matched MeSH terms: Photochemotherapy*
  6. Wong JG, Lai XJ, Sarafian RY, Wong HS, Smith JB
    Int Med Case Rep J, 2017;10:51-54.
    PMID: 28243154 DOI: 10.2147/IMCRJ.S107648
    We report a case of a Caucasian female who developed active polypoidal choroidal vasculopathy (PCV) at the edge of a stable choroidal nevus and was successfully treated with verteporfin photodynamic therapy. No active polyp was detectable on indocyanine green angiography 2 years after treatment, and good vision was maintained. Indocyanine green angiography is a useful investigation to diagnose PCV and may be underutilized. Unlike treatment of choroidal neovascularization secondary to choroidal nevus, management of PCV secondary to nevus may not require intravitreal anti-vascular endothelial growth factor therapy. Photodynamic monotherapy may be an effective treatment of secondary PCV.
    Matched MeSH terms: Photochemotherapy
  7. Vohra F, Al-Kheraif AA, Qadri T, Hassan MI, Ahmed A, Warnakulasuriya S, et al.
    Photodiagnosis Photodyn Ther, 2015 Mar;12(1):150-9.
    PMID: 25315968 DOI: 10.1016/j.pdpdt.2014.10.001
    The aim was to systematically review the efficacy of photodynamic therapy (PDT) in the management of oral premalignant lesions.
    Matched MeSH terms: Photochemotherapy/statistics & numerical data*
  8. Voon SH, Kiew LV, Lee HB, Lim SH, Noordin MI, Kamkaew A, et al.
    Small, 2014 Dec 29;10(24):4993-5013.
    PMID: 25164105 DOI: 10.1002/smll.201401416
    Animal models, particularly rodents, are major translational models for evaluating novel anticancer therapeutics. In this review, different types of nanostructure-based photosensitizers that have advanced into the in vivo evaluation stage for the photodynamic therapy (PDT) of cancer are described. This article focuses on the in vivo efficacies of the nanostructures as delivery agents and as energy transducers for photosensitizers in animal models. These materials are useful in overcoming solubility issues, lack of tumor specificity, and access to tumors deep in healthy tissue. At the end of this article, the opportunities made possible by these multiplexed nanostructure-based systems are summarized, as well as the considerable challenges associated with obtaining regulatory approval for such materials. The following questions are also addressed: (1) Is there a pressing demand for more nanoparticle materials? (2) What is the prognosis for regulatory approval of nanoparticles to be used in the clinic?
    Matched MeSH terms: Photochemotherapy*
  9. Chin Y, Lim SH, Zorlu Y, Ahsen V, Kiew LV, Chung LY, et al.
    PLoS One, 2014;9(5):e97894.
    PMID: 24840576 DOI: 10.1371/journal.pone.0097894
    Phthalocyanines are excellent photosensitizers for photodynamic therapy as they have strong absorbance in the near infra-red region which is most relevant for in vivo activation in deeper tissular regions. However, most phthalocyanines present two major challenges, ie, a strong tendency to aggregate and low water-solubility, limiting their effective usage clinically. In the present study, we evaluated the potential enhancement capability of glycerol substitution on the photodynamic properties of zinc (II) phthalocyanines (ZnPc). Three glycerol substituted ZnPc, 1-3, (tetra peripherally, tetra non-peripherally and mono iodinated tri non-peripherally respectively) were evaluated in terms of their spectroscopic properties, rate of singlet oxygen generation, partition coefficient (log P), intracellular uptake, photo-induced cytotoxicity and vascular occlusion efficiency. Tetrasulfonated ZnPc (ZnPcS4) was included as a reference compound. Here, we showed that 1-3 exhibited 10-100 nm red-shifted absorption peaks with higher molar absorptivity, and at least two-fold greater singlet oxygen generation rates compared to ZnPcS4. Meanwhile, phthalocyanines 1 and 2 showed more hydrophilic log P values than 3 consistent with the number of glycerol attachments but 3 was most readily taken up by cells compared to the rest. Both phthalocyanines 2 and 3 exhibited potent phototoxicity against MCF-7, HCT-116 and HSC-2 cancer cell-lines with IC50 ranging 2.8-3.2 µM and 0.04-0.06 µM respectively, while 1 and ZnPcS4 (up to 100 µM) failed to yield determinable IC50 values. In terms of vascular occlusion efficiency, phthalocyanine 3 showed better effects than 2 by causing total occlusion of vessels with diameter <70 µm of the chorioallantoic membrane. Meanwhile, no detectable vascular occlusion was observed for ZnPcS4 with treatment under similar experimental conditions. These findings provide evidence that glycerol substitution, in particular in structures 2 and 3, is able to improve the photodynamic properties of ZnPc.
    Matched MeSH terms: Photochemotherapy/methods*
  10. Ong CY, Ling SK, Ali RM, Chee CF, Samah ZA, Ho AS, et al.
    J. Photochem. Photobiol. B, Biol., 2009 Sep 4;96(3):216-22.
    PMID: 19647445 DOI: 10.1016/j.jphotobiol.2009.06.009
    One hundred and fifty-five extracts from 93 terrestrial species of plants in Peninsula Malaysia were screened for in vitro photo-cytotoxic activity by means of a cell viability test using a human leukaemia cell-line HL60. These plants which can be classified into 43 plant families are diverse in their type of vegetation and their natural habitat in the wild, and may therefore harbour equally diverse metabolites with potential pharmaceutical properties. Of these, 29 plants, namely three from each of the Clusiaceae, Leguminosae, Rutaceae and Verbenaceae families, two from the Piperaceae family and the remaining 15 are from Acanthaceae, Apocynaceae, Bignoniaceae, Celastraceae, Chrysobalanaceae, Irvingiaceae, Lauraceae, Lythraceae, Malvaceae, Meliaceae, Moraceae, Myristicaceae, Myrsinaceae, Olacaceae and Sapindaceae. Hibiscus cannabinus (Malvaceae), Ficus deltoidea (Moraceae), Maranthes corymbosa (Chrysobalanaceae), Micromelum sp., Micromelum minutum and Citrus hystrix (Rutaceae), Cryptocarya griffithiana (Lauraceae), Litchi chinensis (Sapindaceae), Scorodocarpus bornensis (Olacaceae), Kokoona reflexa (Celastraceae), Irvingia malayana (Irvingiaceae), Knema curtisii (Myristicaceae), Dysoxylum sericeum (Meliaceae), Garcinia atroviridis, Garcinia mangostana and Calophyllum inophyllum (Clusiaceae), Ervatamia hirta (Apocynaceae), Cassia alata, Entada phaseoloides and Leucaena leucocephala (Leguminosae), Oroxylum indicum (Bignoniaceae), Peronema canescens,Vitex pubescens and Premna odorata (Verbenaceae), Piper mucronatum and Piper sp. (Piperaceae), Ardisia crenata (Myrsinaceae), Lawsonia inermis (Lythraceae), Strobilanthes sp. (Acanthaceae) were able to reduce the in vitro cell viability by more than 50% when exposed to 9.6J/cm(2) of a broad spectrum light when tested at a concentration of 20 microg/mL. Six of these active extracts were further fractionated and bio-assayed to yield four photosensitisers, all of which are based on the pheophorbide-a and -b core structures. Our results suggest that the main photosensitisers from terrestrial plants are likely based on the cyclic tetrapyrrole structure and photosensitisers with other structures, if present, are present in minor amounts or are not as active as those with the cyclic tetrapyrrole structure.
    Matched MeSH terms: Photochemotherapy*
  11. Alshammary F, Karobari MI, Assiry AA, Marya A, Shaikh GM, Siddiqui AA, et al.
    Biomed Res Int, 2021;2021:5523242.
    PMID: 34036099 DOI: 10.1155/2021/5523242
    This study is aimed at assessing the influence of Nd:YAG, Er,Cr:YSGG laser irradiation, and adjunctive photodynamic therapy (aPDT) on the bond strength of zirconia posts to radicular dentin. Eighty extracted anterior teeth were randomly categorized into 4 groups (n = 20) based on varying laser irradiation treatments, i.e., conventional cleaning and shaping (CCS), Nd:YAG, Er,Cr:YSGG, and aPDT group, respectively. Using a cutting machine, the samples were prepared for push-out bond strength analysis; 4 sections (2 on each apical and cervical) of around 1 mm thickness were sectioned for all roots at a right angle to the long axis of the post. After making the space for the post, they were incorporated into the root system and were subjected to different laser treatments. The universal testing machine was utilized to assess the push-out bond strength, which had a defined 1 mm/minute crosshead speed until the failure was encountered. Specimens in the aPDT group (8.20 ± 2.14 MPa) demonstrated the highest mean push-out bond strength, whereas the lowest was shown by samples in the CCS group (7.08 ± 1.11 MPa). According to the independent t-test, the mean push-out bond strength scores of the cervical segments were higher as compared to the apical segments in research groups (p < 0.05). Overall, the adhesive type was the most frequently encountered failure mode in all of the experimental groups, with the least number of failures observed in aPDT treated teeth samples. In conclusion, the push-out bond strength to radicular dentin was not much influenced by Nd:YAG, Er,Cr:YSGG laser, and aPDT in comparison with CCS. Although statistically not significant, however, the application of aPDT provided better outcomes as compared to other research groups.
    Matched MeSH terms: Photochemotherapy/methods*
  12. Jukapli NM, Bagheri S
    J. Photochem. Photobiol. B, Biol., 2016 Oct;163:421-30.
    PMID: 27639172 DOI: 10.1016/j.jphotobiol.2016.08.046
    This review provides a background, fundamental and advanced application of titania nanoparticles (TiO2) on the disinfection and killing of cancer cell through photocatalytic chemistry. It starts with the characteristic properties focused on the surface, light sensitivity, crystallinity and toxicology of TiO2 as a photocatalyst. Consequently, outline and design of photocatalytic reactor has been figured out based on the target organisms, including bacteria, viruses, fungi and cancer cells. Despite a large number of studies undertaken, limited selectivity and efficacy of TiO2 photocatalyst are still widely accepted problems. An ideal TiO2 photocatalyst should have the combined properties of highly stable reactive oxygen species yield and a greater degree of selectivity towards cancerous cell without damaging the healthy tissues. Hybridization of TiO2 with metal, metal oxide and carbon nano materials significantly improved both of stability and selectivity of TiO2, whilst maintaining its high Photodynamic reactivity.
    Matched MeSH terms: Photochemotherapy/methods*
  13. Kiew LV, Cheah HY, Voon SH, Gallon E, Movellan J, Ng KH, et al.
    Nanomedicine, 2017 05;13(4):1447-1458.
    PMID: 28214608 DOI: 10.1016/j.nano.2017.02.002
    In photodynamic therapy (PDT), the low absorptivity of photosensitizers in an aqueous environment reduces singlet oxygen generation efficiency and thereby decreases photosensitizing efficacy in biological conditions. To circumvent this problem, we designed a phthalocyanine-poly-L-glutamic acid conjugate (1-PG) made from a new phthalocyanine (Pc 1) monofunctionalized to allow adequate conjugation to PGA. The resulting 1-PG conjugate retained high absorptivity in the near-infrared (NIR) region at its λmax675nm in an aqueous environment. The 1-PG conjugate demonstrated good singlet oxygen generation efficiency, increased uptake by 4 T1 breast cancer cells via clathrin-mediated endocytosis, and enhanced photocytotoxic efficacy. The conjugate also displayed a high light-dark toxicity ratio, approximately 1.5-fold greater than zinc phthalocyanine at higher concentration (10 μM), an important feature for the reduction of dark toxicity and unwanted side effects. These results suggest that the 1-PG conjugate could be a useful alternative for deep tissue treatment with enhanced anti-cancer (PDT) efficacy.
    Matched MeSH terms: Photochemotherapy*
  14. Makhadmeh GN, Abdul Aziz A
    Artif Cells Nanomed Biotechnol, 2018;46(sup3):S1043-S1046.
    PMID: 30449196 DOI: 10.1080/21691401.2018.1528982
    BACKGROUND: Achieved Silica Nanoparticles (SiNPs) to encapsulate the photosensitizer [Protoporphyrin IX (PpIX)] in photodynamic therapy (PDT) application was reported in this research.

    MATERIALS AND METHODS: Cytotoxicity for five different concentrations of encapsulated and naked PpIX was measured. Optimum concentration and optimum exposure time of encapsulated and naked PpIX that needed to destroy the cells (Osteosarcoma cells) was measured.

    RESULTS: The results showed that the encapsulated PpIX has more efficacy compared to the naked PpIX and the applicability of the encapsulated PpIX-SiNPs was proved on osteosarcoma cells.

    CONCLUSION: The results established the important in-vitro photodynamic effectiveness of PpIX-SiNP, which may open a new application for PpIX in its clinical and in-vitro studies.

    Matched MeSH terms: Photochemotherapy*
  15. Greco G, Di Piazza S, Chan J, Zotti M, Hanna R, Gheno E, et al.
    Photodiagnosis Photodyn Ther, 2020 Mar;29:101575.
    PMID: 31614222 DOI: 10.1016/j.pdpdt.2019.10.010
    BACKGROUND: A large number of systemic diseases can be linked to oral candida pathogenicity. The global trend of invasive candidiasis has increased progressively and is often accentuated by increasing Candida albicans resistance to the most common antifungal medications. Photodynamic therapy (PDT) is a promising therapeutic approach for oral microbial infections. A new formulation of 5-aminolevulinic acid (5%ALA) in a thermosetting gel (t) (5%ALA-PTt) was patented and recently has become available on the market. However, its antimicrobial properties, whether mediated or not by PDT, are not yet known. In this work we characterised them.

    METHODS: We isolated a strain of C. albicans from plaques on the oral mucus membrane of an infected patient. Colonies of this strain were exposed for 1 24 h, to 5%ALA-PTt, 5%ALA-PTt buffered to pH 6.5 (the pH of the oral mucosa) (5%ALA-PTtb) or not exposed (control). The 1 h-exposed samples were also irradiated at a wavelength of 630 nm with 0.14 watts (W) and 0.37 W/cm2 for 7 min at a distance of <1 mm.

    RESULTS AND CONCLUSION: The 5% ALA-PTt preparation was shown to be effective in reducing the growth of biofilm and inoculum of C. albicans. This effect seems to be linked to the intrinsic characteristics of 5%ALA-TPt, such acidic pH and the induction of free radical production. This outcome was significantly enhanced by the effect of PDT at relatively short incubation and irradiation times, which resulted in growth inhibition of both treated biofilm and inoculum by ∼80% and ∼95%, respectively.

    Matched MeSH terms: Photochemotherapy/methods*
  16. Sugito SFA, Wibrianto A, Chang JY, Fahmi MZ, Khairunisa SQ, Sakti SCW, et al.
    Dalton Trans, 2024 Jul 09;53(27):11368-11379.
    PMID: 38896134 DOI: 10.1039/d4dt01123f
    The design of multimodal cancer therapy was focused on reaching an efficient process and minimizing harmful effects on patients. In the present study, the Au-MnO2 nanostructures have been successfully constructed and produced as novel multipurpose photosensitive agents simultaneously for photodynamic therapy (PDT), photothermal therapy (PTT), and chemodynamic therapy (CDT). The prepared AuNPs were conjugated with MnO2 NPs by its participation in the thermal decomposition process of KMnO4 confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR) spectroscopy (FT-IR). The 16.5 nm Au-MnO2 nanostructure exhibited an absorbance at 438 nm, which is beneficial for application in light induction therapy due to the NIR band, as well as its properties of generating reactive oxygen species (ROS) associated with the 808 nm laser light for PDT. The photothermal transduction efficiency was calculated and compared with that of the non-irradiated nanostructure, in which it was found that the 808 nm laser induced a high efficiency of 83%, 41.5%, and 37.5% for PDT, PTT, and CDT, respectively. The results of DPBF and TMB assays showed that the efficiency of PDT and PTT was higher than that of CDT. The nanostructure also confirmed the time-dependent peroxidase properties at different H2O2, TMB, and H2TMB concentrations, promising good potency in applying nanomedicine in clinical cancer therapy.
    Matched MeSH terms: Photochemotherapy*
  17. Tew LS, Cai MT, Lo LW, Khung YL, Chen NT
    Materials (Basel), 2018 Jul 09;11(7).
    PMID: 29987236 DOI: 10.3390/ma11071170
    Photodynamic therapy (PDT) is a cancer treatment that employs the production of cytotoxic reactive oxygen species (ROS), subsequently triggering tumor apoptosis and tumor size reduction. However, this approach suffers from insufficient light penetration depth. In order to mitigate this issue, pollen-structured gold clusters (PSGCs) were designed for mediating X-ray-induced PDT for radiotherapy enhancement. The structure of PSGCs provides a large surface area that is able to generate ROS upon X-ray irradiation. The synthesized PSGCs were exposed to different X-ray doses and the generated ROS was then quantified by dihydroethidium (DHE) assay. Furthermore, at the cellular level, the PDT efficacy of PSGCs was evaluated via immunofluorescence staining with γ-H2AX and comet assay. The results demonstrated that PSGCs possess a significantly high ROS-generating capacity and a remarkable PDT efficacy in the treatment of breast cancer cells, thus showing potential clinical uses in deep-tissue cancer treatment.
    Matched MeSH terms: Photochemotherapy
  18. Samat N, Tan PJ, Shaari K, Abas F, Lee HB
    Anal Chem, 2014 Feb 4;86(3):1324-31.
    PMID: 24405504 DOI: 10.1021/ac403709a
    Photodynamic therapy (PDT) is an alternative treatment for cancer that involves administration of a photosensitive drug or photosensitizer that localizes at the tumor tissue followed by in situ excitation at an appropriate wavelength of light. Tumour tissues are then killed by cytotoxic reactive oxygen species generated by the photosensitizer. Targeted excitation and photokilling of affected tissues is achieved through focal light irradiation, thereby minimizing systemic side effects to the normal healthy tissues. Currently, there are only a small number of photosensitizers that are in the clinic and many of these share the same structural core based on cyclic tetrapyrroles. This paper describes how metabolic tools are utilized to prioritize natural extracts to search for structurally new photosensitizers from Malaysian biodiversity. As proof of concept, we analyzed 278 photocytotoxic extracts using a hyphenated technique of liquid chromatography-mass spectrometry coupled with principal component analysis (LC-MS-PCA) and prioritized 27 extracts that potentially contained new photosensitizers for chemical dereplication using an in-house UPLC-PDA-MS-Photocytotoxic assay platform. This led to the identification of 2 new photosensitizers with cyclic tetrapyrrolic structures, thereby demonstrating the feasibility of the metabolic approach.
    Matched MeSH terms: Photochemotherapy*
  19. Alwaeli HA, Al-Khateeb SN, Al-Sadi A
    Lasers Med Sci, 2015 Feb;30(2):801-7.
    PMID: 24037036 DOI: 10.1007/s10103-013-1426-y
    Mechanical removal of microbial biofilm dental plaque from tooth surfaces is important for treatment of periodontal diseases. However, the effectiveness of conventional scaling and root planing (SRP) is affected by the local conditions and residual bacteria which may affect the healing process. We performed a randomized clinical trial to test our hypothesis that adjunctive antimicrobial photodynamic therapy (aPDT) plus SRP has significant effect compared with SRP alone, which can last for 1 year. The study included 136 sites in 16 patients with previously untreated chronic periodontitis, at least one premolar and one molar in every quadrant (minimum, four teeth/quadrant) and at least one tooth with attachment loss of ≥4 mm in every quadrant. In all patients, two randomly assigned quadrants were treated with SRP and the other two were treated with SRP + aPDT. The clinical parameters of probing pocket depth (PPD), bleeding on probing (BOP), and clinical attachment level (CAL) were evaluated at baseline and after 3, 6, and 12 months. There were no significant differences between the two groups at baseline. PPD and BOP showed significant reduction, and CAL showed significant gain from baseline for all three time points in both groups. In addition, there were significantly greater reduction and gain for SRP + aPDT than for SRP at all three time points. No adverse effects of aPDT were observed. These data demonstrate significant improvement in all evaluated clinical parameters for at least 1 year and suggest that aPDT as an adjunctive therapy to SRP represents a promising therapeutic concept for persistent periodontitis.
    Matched MeSH terms: Photochemotherapy/methods*
  20. Kamal N, Sabaratnam V, Abdullah N, Ho AS, Teo SH, Lee HB
    Antonie Van Leeuwenhoek, 2009 Feb;95(2):179-88.
    PMID: 19125347 DOI: 10.1007/s10482-008-9301-8
    Photodynamic therapy (PDT) is a promising cancer treatment which involves activation of a photosensitizing drug with light to produce reactive oxygen species that kill tumors without causing damage to unirradiated normal tissues. To date, only Photofrin, Foscan and Levulan have been approved for clinical treatment of cancer. Tropical habitats such as those found in Malaysia are attractive sources of new therapeutic compounds as tremendous chemical diversity is found in a large number of plants, animals, marine- and micro-organisms. In our screening program for novel photosensitizers from nature, colorful strains of fungi (from Aspergillus and Penicillium genus) and bacteria (including actinomycetes and photosynthetic bacteria) were collected from various habitats in Peninsular Malaysia, such as coastal soil, peat soil, marine sponges and wastewater ponds. Methanolic extracts from a total of 85 different species were evaluated with a short-term cell viability assay for photo-cytotoxicity, where a promyelocytic leukemia cell-line, HL60 incubated with 20 microg/ml of extracts was irradiated with 9.6 J/cm(2) of a broad spectrum light. Two of these extracts, one from Rhodobacter sphaeroides (PBUM003) and one from Rhodopseudomonas palustris (PBUM001) showed moderate to strong photo-cytotoxicity. Subsequent bioassay guided isolation of the PBUM001 extract yielded known photosensitisers that are based on bacteriochlorophyll-a by comparing their molecular weight data, HPLC profiles and UV-vis absorption spectra with literature values, thereby demonstrating the validity of our screening approach.
    Matched MeSH terms: Photochemotherapy*
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