Showing items 1 - 20 of 42

Oxygen-independent antimicrobial photoinactivation : Type III photochemical Mechanism?

- Hamblin, Michael R., Abrahamse, Heidi

Recent advances in porphyrin-based inorganic nanoparticles for cancer treatment

- Montaseri, Hanieh, Kruger, Cherie Ann, Abrahamse, Heidi

Genetic aberrations associated with photodynamic therapy in colorectal cancer cells

- Abrahamse, Heidi, Houreld, Nicolette Nadene

  • Authors: Abrahamse, Heidi , Houreld, Nicolette Nadene
  • Date: 2019
  • Subjects: Photodynamic therapy, Colorectal cancer, Zinc phthalocyanine;
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/396389 , uj:32909 , Citation : Abrahamse, H. 2019. Genetic aberrations associated with photodynamic therapy in colorectal cancer cells @ Houreld, N.N. , http://dx.doi.org/10.3390/ijms20133254
  • Description: Abstract : Photodynamic therapy (PDT) is a cancer treatment modality that utilizes three components: light (λ 650–750 nm), a photosensitizer (PS) and molecular oxygen, which upon activation renders the modality effective. Colorectal cancer has one of the highest incident rates as well as a high mortality rate worldwide. In this study, a zinc (Zn) metal-based phthalocyanine (ZnPcSmix) PS was used to determine its efficacy for the treatment of colon adenocarcinoma cells (DLD-1 and Caco-2). Photoactivation of the PS was achieved by laser irradiation at a wavelength of 680 nm. Dose responses were performed to establish optimal PS concentration and irradiation fluence. A working combination of 20 µM ZnPcSmix and 5 J/cm2 was used. Biochemical responses were determined after 1 or 24 h incubation post-treatment. Since ZnPcSmix is localized in lysosomes and mitochondria, mitochondrial destabilization analysis was performed monitoring mitochondrial membrane potential (MMP). Cytosolic acidification was determined measuring hydrogen peroxide (H2O2) levels in the cytoplasm. Having established apoptotic cell death induction, an apoptosis PCR array was performed to establish the apoptotic mechanism. In DLD-1 cells, expression of genes included 3 up-regulated and 20 down-regulated genes while in Caco-2 cells, there were 16 up-regulated and 22 down-regulated genes. In both cell lines, in up-regulated genes, there was a combination of pro- and anti-apoptotic genes that were significantly expressed. Gene expression results showed that more tumorigenic cells (DLD-1) went through apoptosis; however, they exhibit increased risk of resistance and recurrence, while less tumorigenic Caco-2 cells responded better to PDT, thus being suggestive of a better prognosis post-PDT treatment. In addition, the possible apoptotic mechanisms of cell death were deduced based on the genetic expression profiling of regulatory apoptotic inducing factors.
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Targeted photodynamic therapy as potential treatment modality for the eradicaiton of colon cancer

- Kruger, Cherie Ann, Abrahamse, Heidi

  • Authors: Kruger, Cherie Ann , Abrahamse, Heidi
  • Date: 2019
  • Subjects: Colorectal cancer , Photodynamic therapy , Photosensitizer
  • Language: English
  • Type: Book chapter
  • Identifier: http://hdl.handle.net/10210/407617 , uj:34318 , Citation: Kruger, C.A., Abrahamse, H. 2019: Targeted photodynamic therapy as potential treatment modality for the eradicaiton of colon cancer.
  • Description: Abstract: Photodynamic therapy (PDT) can be used to treat colorectal cancer (CRC). When a photosensitizer (PS) drug is administered to a patient, it can either passively or actively accumulate within a tumor site and once exposed to a specific wavelength of light, it is excited to produce reactive oxygen species (ROS), resulting in tumor destruction. However, the efficacy of ROS generation for tumor damage is highly dependent on the uptake of the PS in tumor cells. Thus, PS targeted uptake and delivery in CRC tumor cells is a crucial factor in PDT cancer drug absorption studies. Generally, within non-targeted drug delivery mechanisms, only minor amounts of PS passively accumulate in tumor sites and the remainder distributes into healthy tissues, causing unwanted side effects. To improve the efficacy of PDT research is currently focused on the development of specific receptor based photosynthetic nanocarrier platform drugs, which promote the active uptake and absorption of PS drugs in CRC tumor sites only, avoiding unwanted side effects, as well as treatment enhancement. This chapter will focus on current actively targeted PS nanoparticle drug delivery systems, which have been investigated for the PDT treatment of CRC cancer.
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Targeted photodynamic therapy treatment of in vitro A375 metastatic melanoma cells

- Naidoo, Channay, Kruger, Cherie Ann, Abrahamse, Heidi

  • Authors: Naidoo, Channay , Kruger, Cherie Ann , Abrahamse, Heidi
  • Date: 2019
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/401324 , uj:33533 , Citation: Naidoo, C., Kruger, C.A. & Abrahamse, H. 2019. Targeted photodynamic therapy treatment of in vitro A375 metastatic melanoma cells. Oncotarget, 10(58):6079-6095.
  • Description: Abstract: Metastatic Melanoma (MM) is a deadly form of skin cancer and many photodynamic therapy (PDT) studies have noted limitations in relation to effective photosensitizer (PS) drug uptake in tumors. The focus of this study was to develop a PS multicomponent nanoparticle drug conjugate carrier system which specifically targets MM cells via biomarkers to actively enhance PS delivery and so improve MM PDT. An antibody-metallated phthalocyanine-polyethylene glycol-gold nanoparticle drug conjugate, was successfully synthesized and characterized. PS active drug targeting PDT experiments at 673 nm were conducted within in vitro cultured MM. Results noted that this drug conjugate enhanced the PDT treatment of MM, through improved subcellular localization of the PS, as well as noted significantly improved cytotoxic and late apoptotic cellular death in cells. The results from this study demonstrate that through the bio-active antibody PS drug targeting of MM, the efficacy of PDT treatment for this cancer can be enhanced.
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The influence of light on reactive oxygen species and NF-êB in disease progression

- Rajendran, Naresh Kumar, George, Blassan P., Chandran, Rahul, Tynga, Ivan Mfouo, Houreld, Nicolette, Abrahamse, Heidi

Apoptotic efficacy of multifaceted biosynthesized silver nanoparticles on human adenocarcinoma cells

- George, Blassan Plackal Adimuriyil, Kumar, Neeraj, Abrahamse, Heidi, Ray, Suprakas Sinha

  • Authors: George, Blassan Plackal Adimuriyil , Kumar, Neeraj , Abrahamse, Heidi , Ray, Suprakas Sinha
  • Date: 2018
  • Language: English
  • Type: Article
  • Identifier: http://ujcontent.uj.ac.za8080/10210/387555 , http://hdl.handle.net/10210/280207 , uj:30105 , Citation: George, B.P.A., Kumar, N., Abrahamse, H. & Ray, S.S. 2018. Apoptotic efficacy of multifaceted biosynthesized silver nanoparticles on human adenocarcinoma cells.
  • Description: Abstract: Metallic nanoparticles (NPs) especially silver (Ag) NPs have shown immense potential in medical applications due to their distinctive physio-chemical and biological properties. This article reports the conjugation of Ag NPs with Rubus fairholmianus extract. The modification of Ag NPs was confirmed using various physico-chemical characterization techniques. The cytotoxic effect of Rubus-conjugated Ag NPs (RAgNPs) was studied by LDH assay and proliferation by ATP assay. The apoptotic inducing ability of the NPs were investigated by Annexin V/PI staining, caspase 3/7 analysis, cytochrome c release, intracellular ROS analysis, Hoechst staining and mitochondrial membrane potential analysis using flow cytometry. The expression of apoptotic proteins caspase 3, Bax and P53 were analyzed using ELISA and caspase 3, Bax using western blotting. Cells treated with 10 µg/mL RAgNPs showed an increased number of cell death by microscopic analysis compared to untreated control cells. The RAgNPs induced a statistically significant dose-dependent decrease in proliferation (p < 0.001 for 5 and 10 µg/mL) and increased cytotoxicity in MCF-7 cells. A 1.83 fold increase in cytotoxicity was observed in cells treated with 10 µg/mL (p < 0.05) compared to the untreated cells. Nuclear damage and intracellular ROS production were observed upon treatment with all tested concentrations of RAgNPs and the highest concentrations (5 and 10 µg/mL) showed significant (p < 0.05, p < 0.01) expression of caspase 3, Bax and P53 proteins. The data strongly suggest that RAgNPs induces cell death in MCF-7 cells through the mitochondrial-mediated intrinsic apoptosis pathway. The present investigation supports the potential of RAgNPs in anticancer drug development.
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Cell adhesion molecules are mediated by photobiomodulation at 660 nm in diabetic wounded fibroblast cells

- Houreld, Nicolette N., Ayuk, Sandra M., Abrahamse, Heidi

  • Authors: Houreld, Nicolette N. , Ayuk, Sandra M. , Abrahamse, Heidi
  • Date: 2018
  • Subjects: Diabetes , Extracellular matrix , Fibroblasts
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/268765 , uj:28535 , Citation: Houreld, N.N., Ayuk, S.M. & Abrahamse, H. 2018. Cell adhesion molecules are mediated by photobiomodulation at 660 nm in diabetic wounded fibroblast cells. Cells 2018, 7:1-17. doi:10.3390/cells7040030
  • Description: Abstract: Diabetes affects extracellular matrix (ECM) metabolism, contributing to delayed wound healing and lower limb amputation. Application of light (photobiomodulation, PBM) has been shown to improve wound healing. This study aimed to evaluate the influence of PBM on cell adhesion molecules (CAMs) in diabetic wound healing. Isolated human skin fibroblasts were grouped into a diabetic wounded model. A diode laser at 660 nm with a fluence of 5 J/cm2 was used for irradiation and cells were analysed 48 h post-irradiation. Controls consisted of sham-irradiated (0 J/cm2) cells. Real-time reverse transcription (RT) quantitative polymerase chain reaction (qPCR) was used to determine the expression of CAM-related genes. Ten genes were up-regulated in diabetic wounded cells, while 25 genes were down-regulated. Genes were related to transmembrane molecules, cell–cell adhesion, and cell–matrix adhesion, and also included genes related to other CAM molecules. PBM at 660 nm modulated gene expression of various CAMs contributing to the increased healing seen in clinical practice. There is a need for new therapies to improve diabetic wound healing. The application of PBM alongside other clinical therapies may be very beneficial in treatment.
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Evaluation of cell damage induced by irradiated Zinc-Phthalocyanine-gold dendrimeric nanoparticles in a breast cancer cell line

- Mfouo-Tynga, Ivan, Houreld, Nicolette Nadene, Abrahamse, Heidi

Inorganic salts and antimicrobial photodynamic Therapy : mechanistic conundrums?

- Hamblin, Michael R., Abrahamse, Heidi

  • Authors: Hamblin, Michael R. , Abrahamse, Heidi
  • Date: 2018
  • Subjects: Antimicrobial photodynamic inactivation , Potentiation by inorganic salts , Sodium azide
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/289251 , uj:31380 , Citation: Hamblin, M.R. & Abrahamse, H. 2018. Inorganic salts and antimicrobial photodynamic Therapy : mechanistic conundrums?. Molecules 2018, 23, 3190; doi:10.3390/molecules23123190
  • Description: Abstract: We have recently discovered that the photodynamic action of many different photosensitizers (PSs) can be dramatically potentiated by addition of a solution containing a range of different inorganic salts. Most of these studies have centered around antimicrobial photodynamic inactivation that kills Gram-negative and Gram-positive bacteria in suspension. Addition of nontoxic water-soluble salts during illumination can kill up to six additional logs of bacterial cells (one million-fold improvement). The PSs investigated range from those that undergo mainly Type I photochemical mechanisms (electron transfer to produce superoxide, hydrogen peroxide, and hydroxyl radicals), such as phenothiazinium dyes, fullerenes, and titanium dioxide, to those that are mainly Type II (energy transfer to produce singlet oxygen), such as porphyrins, and Rose Bengal. At one extreme of the salts is sodium azide, that quenches singlet oxygen but can produce azide radicals (presumed to be highly reactive) via electron transfer from photoexcited phenothiazinium dyes. Potassium iodide is oxidized to molecular iodine by both Type I and Type II PSs, but may also form reactive iodine species. Potassium bromide is oxidized to hypobromite, but only by titanium dioxide photocatalysis (Type I). Potassium thiocyanate appears to require a mixture of Type I and Type II photochemistry to first produce sulfite, that can then form the sulfur trioxide radical anion. Potassium selenocyanate can react with either Type I or Type II (or indeed with other oxidizing agents) to produce the semi-stable selenocyanogen (SCN)2. Finally, sodium nitrite may react with either Type I or Type II PSs to produce peroxynitrate (again, semi-stable) that can kill bacteria and nitrate tyrosine. Many of these salts (except azide) are non-toxic, and may be clinically applicable.
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Nano-mediated photodynamic therapy for Cancer : enhancement of cancer specificity and therapeutic effects

- Mfouo Tynga, Ivan, Abrahamse, Heidi

Photodynamic therapy for metastatic melanoma treatment : a review

- Naidoo, Channay, Kruger, Cherie Ann, Abrahamse, Heidi

  • Authors: Naidoo, Channay , Kruger, Cherie Ann , Abrahamse, Heidi
  • Date: 2018
  • Subjects: Malignant melanoma , Photodynamic therapy (PDT) , Photosensitizers
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/278193 , uj:29848 , Citation: Naidoo, C., Kruger, C.A. & Abrahamse, H. 2018. Photodynamic therapy for metastatic melanoma treatment : a review. Technology in Cancer Research & Treatment Volume 17: 1-15 2018 Article reuse guidelines: sagepub.com/journals-permissions DOI: 10.1177/1533033818791795 journals.sagepub.com/home/tct
  • Description: Abstract: This review article is based on specifically targeted nanoparticles that have been used in the treatment of melanoma. According to the Skin Cancer Foundation, within 2017 an estimated 9730 people will die due to invasive melanoma. Conventional treatments for nonmalignant melanoma include surgery, chemotherapy, and radiation. For the treatment of metastatic melanoma, 3 therapeutic agents have been approved by the Food and Drug Administration: dacarbazine, recombinant interferon a-2b, and highdose interleukin 2. Photodynamic therapy is an alternative therapy that activates a photosensitizer at a specific wavelength forming reactive oxygen species which in turn induces cell death; it is noninvasive with far less side effects when compared to conventional treatments. Nanoparticles are generally conjugated to photosynthetic drugs, since they are biocompatible, stabile, and durable, as well as have a high loading capacity, which improve either passive or active photosensitizer drug delivery to targeted cells. Therefore, various photosynthetic drugs and nanoparticle drug delivery systems specifically targeted for melanoma were analyzed in this review article in relation to either their passive or their active cellular uptake mechanisms in order to deduce the efficacy of photodynamic therapy treatment for metastatic melanoma which currently remains ongoing. The overall findings from this review concluded that no current photodynamic therapy studies have been performed in relation to active nanoparticle platform photosensitizer drug carrier systems for the treatment of metastatic melanoma, and so this type of research requires further investigation into developing a more efficient active nano-photosensitizer carrier smart drug that can be conjugated to specific cell surface receptors and combinative monoclonal antibodies so that a further enhanced and more efficient form of targeted photodynamic therapy for the treatment of metastatic melanoma can be established.
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Photodynamic therapy, a potential therapy for improve cancer management

- Abrahamse, Heidi, Mfouo Tynga, Ivan Sosthene

  • Authors: Abrahamse, Heidi , Mfouo Tynga, Ivan Sosthene
  • Date: 2018
  • Subjects: Cancer , Breast cancer , Current treatment
  • Language: English
  • Type: Book Chapter
  • Identifier: http://hdl.handle.net/10210/289211 , uj:31375 , Citation: Abrahamse, H. & Mfouo Tynga, I.S. 2018. Photodynamic therapy, a potential therapy for improve cancer management. , DOI: http://dx.doi.org/10.5772/intechopen.74697
  • Description: Abstract: Cancer is a mass of abnormal and detrimental cells in a given part of the body. The main elucidated cause is the uncontrolled growth and proliferation of those cells after the corruption of the physiological processes responsible for normal development and functioning. The advantage of adjuvant therapy, therapy done after surgery, is to prevent the occurring of symptoms and not necessarily to make sure of the integrity of mechanisms that are crucial in preventing abnormal cell proliferation such cell cycle regulation, cell death, which include autophagy, necrosis, and apoptosis. The understanding of dysregulated cell death mechanisms combined with suitable alternative cancer therapies could lead to novel treatment modalities for cancer. Currently, breast cancer is the leading occurring cancer in sub-Saharan women after that of the cervix. This potentially curable condition kills more than half of the diagnosed group, which consists mainly of females aged between 35 and 49 years and with 77% being in stages III and IV. The social economic status of populations coupled with the limited access to proper control strategies and infrastructures in sub-Saharan regions accentuate the burden of the disease. Photodynamic therapy (PDT) has shown great potential in treating breast cancer and even greater therapeutic outcomes can be obtained when combining PDT with other therapies such as immunotherapy or nanomedicine.
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Targeted photodynamic therapy : a novel approach to abolition of human cancer stem cells

- Crous, Anine, Chizenga, Elvin, Hodgkinson, Natasha, Abrahamse, Heidi

  • Authors: Crous, Anine , Chizenga, Elvin , Hodgkinson, Natasha , Abrahamse, Heidi
  • Date: 2018
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/278330 , uj:29865 , Citation: Crous, A. et al. 2018. Targeted photodynamic therapy : a novel approach to abolition of human cancer stem cells. International Journal of Optics Volume 2018, Article ID 7317063, 9 pages https://doi.org/10.1155/2018/7317063
  • Description: Abstract: Cancer is a global burden that has prompted extensive research into prevention and treatment, over many decades. Scientific studies have shown that subset of cells within a tumour, known as cancer stem cells (CSCs), are responsible for tumourigenesis, metastasis, drug resistance, and recurrences. CSCs have characteristic features of enhanced self-renewal, proliferation, and limited but multidirectional differentiation capacity. The discovery of CSCs has initiated extensive research into novel cancer treatment regimes. Evidence indicates that CSCs are resistant to conventional chemo- and radiation therapy leading to treatment failures, cancermetastasis, secondary cancer formation, and relapse. Because of the observed phenomena in the course of cancer prognosis, a need for treatment modalities targeting CSCs is important. Photodynamic therapy (PDT) is a clinically approved, minimally invasive, therapeutic procedure that can exert a selective cytotoxic activity toward cancerous cells while reducing toxicity to normal cells. It uses a photosensitizer (PS) that becomes excited when subjected to light at a specific wavelength, and the PS forms reactive oxygen species (ROS) killing malignant cells. Currently, PDT is being investigated as a target specific treatment for CSCs by the addition of carrier molecules and antibody conjugates bound to the PS. Targeted PDT (TPDT) may be able to not only eradicate the tumour mass but kill CSCs as well.
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Targeted photodynamic therapy for improved lung cancer treatment

- Crous, Anine, Abrahamse, Heidi

  • Authors: Crous, Anine , Abrahamse, Heidi
  • Date: 2018
  • Subjects: Lung cancer , Lung cancer stem cells , PDT
  • Language: English
  • Type: Book chapter
  • Identifier: http://hdl.handle.net/10210/283747 , uj:30619 , Citation: Crous, A. & Abrahamse, H. 2008. Targeted photodynamic therapy for improved lung cancer treatment.
  • Description: Abstract: Cancer develops from the outgrowth of a clonal population of cells with a genetic pathology to evade cell death and exponential proliferation. It has become a global burden with increasing mortality rates. Lung cancer is a major contributor to cancer fatalities. Conventional therapies have shown advances in treating lung cancer, but the successful eradication of cancer lies in targeting both cancer and cancer stem cells. Cancer stem cells (CSCs) are a ration of cells found within the tumour bulk, capable of cancer initiation, therapy resistance, metastasis and cancer relapse. Photodynamic therapy (PDT) has proven effective in treating lung cancer. PDT exerts selective cell death mechanisms toward cancerous cells. With the use of a photosensitizer (PS) which becomes excited upon irradiation with laser light at a specific wavelength, the PS forms reactive oxygen species (ROS) in turn killing neoplastic cells. Leading therapeutic sequel can be obtained by transcending PDT though combination therapies such as immunotherapy and nanotechnology which will enable PDT to target lung CSCs preventing lung cancer recurrence.
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Targeted photodynamic therapy for improved lung cancer treatment

- Crous, Anine, Abrahamse, Heidi

  • Authors: Crous, Anine , Abrahamse, Heidi
  • Date: 2018
  • Subjects: Lung cancer , Lung cancer stem cells , PDT
  • Language: English
  • Type: Book Chapter
  • Identifier: http://hdl.handle.net/10210/412204 , uj:34675 , Citation: Crous, A. & Abrahamse, H. 2018. Targeted photodynamic therapy for improved lung cancer treatment.
  • Description: Abstract: Cancer develops from the outgrowth of a clonal population of cells with a genetic pathology to evade cell death and exponential proliferation. It has become a global burden with increasing mortality rates. Lung cancer is a major contributor to cancer fatalities. Conventional therapies have shown advances in treating lung cancer, but the successful eradication of cancer lies in targeting both cancer and cancer stem cells. Cancer stem cells (CSCs) are a ration of cells found within the tumour bulk, capable of cancer initiation, therapy resistance, metastasis and cancer relapse. Photodynamic therapy (PDT) has proven effective in treating lung cancer. PDT exerts selective cell death mechanisms toward cancerous cells. With the use of a photosensitizer (PS) which becomes excited upon irradiation with laser light at a specific wavelength, the PS forms reactive oxygen species (ROS) in turn killing neoplastic cells. Leading therapeutic sequel can be obtained by transcending PDT though combination therapies such as immunotherapy and nanotechnology which will enable PDT to target lung CSCs preventing lung cancer recurrence.
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Therapeutic potential and recent advances of curcumin in the treatment of aging-associated diseases

- Kumar, Sathish Sundar Dhilip, Houreld, Nicolette Nadene, Abrahamse, Heidi

  • Authors: Kumar, Sathish Sundar Dhilip , Houreld, Nicolette Nadene , Abrahamse, Heidi
  • Date: 2018
  • Subjects: Curcumin , Nanoparticle , Plants
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/270261 , uj:28724 , Citation: Kumar, S.S.D., Houreld, N.N. & Abrahamse, H. 2018. Therapeutic potential and recent advances of curcumin in the treatment of aging-associated diseases. Molecules, 23, 835; doi:10.3390/molecules23040835
  • Description: Abstract: Curcumin, a low molecular weight, lipophilic, major yellow natural polyphenolic, and the most well-known plant-derived compound, is extracted from the rhizomes of the turmeric (Curcuma longa) plant. Curcumin has been demonstrated as an effective therapeutic agent in traditional medicine for the treatment and prevention of different diseases. It has also shown a wide range of biological and pharmacological effects in drug delivery, and has actively been used for the treatment of aging-associated diseases, including cardiovascular diseases, atherosclerosis, neurodegenerative diseases, cancer, rheumatoid arthritis, ocular diseases, osteoporosis, diabetes, hypertension, chronic kidney diseases, chronic inflammation and infection. The functional application and therapeutic potential of curcumin in the treatment of aging-associated diseases is well documented in the literature. This review article focuses mainly on the potential role of plant-derived natural compounds such as curcumin, their mechanism of action and recent advances in the treatment of aging-associated diseases. Moreover, the review briefly recaps on the recent progress made in the preparation of nanocurcumins and their therapeutic potential in clinical research for the treatment of aging-associated diseases.
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Utilisation of targeted nanoparticle photosensitiser drug delivery systems for the enhancement of photodynamic therapy

- Kruger, Cherie Ann, Abrahamse, Heidi

  • Authors: Kruger, Cherie Ann , Abrahamse, Heidi
  • Date: 2018
  • Subjects: Photodynamic therapy , Cancer , Nanotechnology
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/279500 , uj:30016 , Citation: Kruger, C.A. & Abrahamse, H. 2018. Utilisation of targeted nanoparticle photosensitiser drug delivery systems for the enhancement of photodynamic therapy. Molecules 2018, 23, 2628; doi:10.3390/molecules23102628
  • Description: Abstract: The cancer incidence world-wide has caused an increase in the demand for effective forms of treatment. One unconventional form of treatment for cancer is photodynamic therapy (PDT). PDT has 3 fundamental factors, namely a photosensitiser (PS) drug, light and oxygen. When a PS drug is administered to a patient, it can either passively or actively accumulate within a tumour site and once exposed to a specific wavelength of light, it is excited to produce reactive oxygen species (ROS), resulting in tumour destruction. However, the efficacy of ROS generation for tumour damage is highly dependent on the uptake of the PS in tumour cells. Thus, PS selective/targeted uptake and delivery in tumour cells is a crucial factor in PDT cancer drug absorption studies. Generally, within non-targeted drug delivery mechanisms, only minor amounts of PS are able to passively accumulate in tumour sites (due to the enhanced permeability and retention (EPR) effect) and the remainder distributes into healthy tissues, causing unwanted side effects and poor treatment prognosis. Thus, to improve the efficacy of PDT cancer treatment, research is currently focused on the development of specific receptor-based PS-nanocarrier platform drugs, which promote the active uptake and absorption of PS drugs in tumour sites only, avoiding unwanted side effects, as well as treatment enhancement. Therefore, the aim of this review paper is to focus on current actively targeted or passively delivered PS nanoparticle drug delivery systems, that have been previously investigated for the PDT treatment of cancer and so to deduce their overall efficacy and recent advancements.
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In vitro combined effect of Doxorubicin and sulfonated zinc Phthalocyanine– mediated photodynamic therapy on MCF-7 breast cancer cells

- Aniogo, Eric Chekwube, George, Blassan Plackal Adimuriyil, Abrahamse, Heidi

  • Authors: Aniogo, Eric Chekwube , George, Blassan Plackal Adimuriyil , Abrahamse, Heidi
  • Date: 2017
  • Subjects: Doxorubicin , Phthalocyanine , Photodynamic therapy
  • Language: English
  • Type: Article
  • Identifier: http://hdl.handle.net/10210/249516 , uj:25966 , Citation: Aniogo, E.C., George, B.P.A. & Abrahamse, H. 2017. In vitro combined effect of Doxorubicin and sulfonated zinc Phthalocyanine– mediated photodynamic therapy on MCF-7 breast cancer cells. Tumor Biology, DOI: 10.1177/1010428317727278
  • Description: Abstract: Doxorubicin is a broad-spectrum antibiotic and anticancer drug used to treat a variety of human malignancies like breast cancer and leukaemia. Unfortunately, a dose-dependent side effect of this drug is common, representing a major obstacle to its use despite its therapeutic efficacy. Photodynamic therapy is an emerging non-invasive potential adjuvant for conventional cancer treatment. In an attempt to circumvent the dose-limiting effect of doxorubicin, this study aimed to investigate cellular anticancer activity of doxorubicin and sulfonated zinc phthalocyanine–mediated photodynamic therapy on MCF-7 cells alone and in combination. Furthermore, we investigated the cell death pathway resulting from the combination treatment. MCF-7 cells were incubated with 0.5 μM concentration of doxorubicin for 20 h, afterwards, various concentrations of sulfonated zinc phthalocyanine were added and incubated for 4 h. Cells were irradiated using a 681.5 nm diode laser at 4.53 mW/cm2 for 18 min 24 s (5 J/cm2). Cell viability and proliferation were measured using trypan blue assay and homogeneous adenosine triphosphate quantitation assay, respectively, while qualitative changes in cellular morphology were observed under inverted light microscopy. Cellular DNA damage was assessed under fluorescent microscopy and Annexin V/propidium iodide stain was used to investigate the cell death pathway. Findings from this study shown that combined treatment with doxorubicin and photodynamic therapy was more effective in inhibiting the proliferation and growth of MCF-7 cells. Overall, the results indicate that combination of smaller dose of doxorubicin with photodynamic therapy is a promising combined treatment strategy for breast carcinoma. However, this combination warrants further investigation.
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Modes of cell death induced by photodynamic therapy using zinc phthalocyanine in lung cancer cells grown as a monolayer and three-dimensional multicellular spheroids.

- Manoto, Sello L., Houreld, Nicolette, Hodgkinson, Natasha, Abrahamse, Heidi

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