Strategies for optimizing the delivery to tumors of macrocyclic photosensitizers used in photodynamic therapy (PDT)

2017 ◽  
Vol 21 (04-06) ◽  
pp. 239-256 ◽  
Author(s):  
Francesca Moret ◽  
Elena Reddi

This review briefly summaries the principles and mechanisms of action of photodynamic therapy (PDT) as concerns its application in the oncological field, highlighting its drawbacks and some of the strategies that have been or are being explored to overcome them. The major aim is to increase the efficiency and selectivity of the photosensitizer (PS) uptake in the cancer cells for optimizing the PDT effects on tumors while sparing normal cells. Some attempts to achieve this are based on the conjugation of the PS to biomolecules (small ligands, peptides) functioning as carriers with the ability to efficiently penetrate cells and/or specifically recognize and bind proteins/receptors overexpressed on the surface of cancer cells. Alternatively, the PS can be entrapped in nanocarriers derived from various types of materials that can target the tumor by exploiting the enhanced permeability and retention (EPR) effects. The use of nanocarriers is particularly attractive because it allows the simultaneous delivery of more than one drug with the possibility of combining PDT with other therapeutic modalities.

2008 ◽  
Vol 2008 ◽  
pp. 1-13 ◽  
Author(s):  
Stephen John Ralph

Arsenic-based compounds have become accepted agents for cancer therapy providing high rates of remission of some cancers such as acute promyelocytic leukemia (APL). The mechanisms by which arsenic-containing compounds kill cells and reasons for selective killing of only certain types of cancer cells such as APLs have recently been delineated. This knowledge was gained in parallel with increasing understanding and awareness of the importance of intracellular redox systems and regulation of the production of reactive oxygen species (ROS) by controlling mitochondrial function. Many of the targets for the arsenic-containing compounds are mitochondrial proteins involved in regulating the production of ROS. Inhibition of these proteins by disulfide linkage of vicinal thiol groups often leads to increased production of ROS and induction of apoptotic signalling pathways. Sensitivity or resistance to the actions of arsenic-containing compounds on cancer cells and normal cells depends on the levels of transport systems for their uptake or efflux from the cells as well as their redox defence mechanisms. The exact mechanisms of arsenic toxicity as well as its anticancer properties are likely to be related and these aspects of arsenic metabolism are covered in this review. Greater understanding of the mechanisms of action of arsenic will help determine the risks of human exposure to this chemical. Novel organic arsenic-containing compounds and the lessons learned from studying their selective sensitivity in targeting dividing endothelial cells to inhibit angiogenesis raise the future possibility for designing better targeted antineoplastic arsenic-containing compounds with less toxicity to normal cells.


Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5990
Author(s):  
Yuan Xu ◽  
Yang Tan ◽  
Xiuqin Ma ◽  
Xiaoyi Jin ◽  
Ye Tian ◽  
...  

Photodynamic therapy (PDT) represents an effective treatment to cure cancer. The targeting ability of the photosensitizer is of utmost importance. Photosensitizers that discriminate cancer cells can avoid the killing of normal cells and improve PDT efficacy. However, the design and synthesis of photosensitizers conjugated with a recognition unit of cancer cell markers is complex and may not effectively target cancer. Considering that the total RNA content in cancer cells is commonly higher than in normal cells, this study has developed the photosensitizer QICY with RNA-targeting abilities for the discrimination of cancer cells. QICY was specifically located in cancer cells rather than normal cells due to their stronger electrostatic interactions with RNA, thereby further improving the PDT effects on the cancer cells. After intravenous injection into mice bearing a xenograft tumor, QICY accumulated into the tumor location through the enhanced permeability and retention effect, automatically targeted cancer cells under the control of RNA, and inhibited tumor growth under 630 nm laser irradiation without obvious side effects. This intelligent photosensitizer with RNA-targeting ability not only simplifies the design and synthesis of cancer-cell-targeting photosensitizers but also paves the way for the further development of highly efficient PDTs.


Author(s):  
Menghan Gao ◽  
Hong Deng ◽  
Weiqi Zhang

: Hyaluronan (HA) is a natural linear polysaccharide that has excellent hydrophilicity, biocompatibility, biodegradability, and low immunogenicity, making it one of the most attractive biopolymers used for biomedical researches and applications. Due to the multiple functional sites on HA and its intrinsic affinity for CD44, a receptor highly expressed on various cancer cells, HA has been widely engineered to construct different drug-loading nanoparticles (NPs) for CD44- targeted anti-tumor therapy. When a cocktail of drugs is co-loaded in HA NP, a multifunctional nano-carriers could be obtained, which features as a highly effective and self-targeting strategy to combat the cancers with CD44 overexpression. The HA-based multidrug nano-carriers can be a combination of different drugs, various therapeutic modalities, or the integration of therapy and diagnostics (theranostics). Up to now, there are many types of HA-based multidrug nano-carriers constructed by different formulation strategies including drug co-conjugates, micelles, nano-gels and hybrid NP of HA and so on. This multidrug nano-carrier takes the full advantages of HA as NP matrix, drug carriers and targeting ligand, representing a simplified and biocompatible platform to realize the targeted and synergistic combination therapy against the cancers. In this review, recent progresses about HA-based multidrug nano-carriers for combination cancer therapy are summarized and its potential challenges for translational applications have been discussed.


2019 ◽  
Vol 18 (15) ◽  
pp. 2156-2168 ◽  
Author(s):  
Magda F. Mohamed ◽  
Nada S. Ibrahim ◽  
Ahmed H.M. Elwahy ◽  
Ismail A. Abdelhamid

Background: Cancer is a complex genetic disease which is characterized by an abnormal cell growth, invasion and spreading to other parts of the body. There are several factors that lead to cancer by causing DNA damage and the impairment of its repair. Treatment of cancer using the chemotherapeutic drugs have adverse side effects such as toxicity as they lose their specificity toward cancer cells and affect also normal cells. Moreover, the cancer cells can resist the chemotherapeutic agents and make them ineffective. For these reasons, much attentions have been paid to develop new drugs with limited side effects on normal cells and to diminish cancer resistance to drug chemotherapy. Recently, some 1,4-dihydropyridine derivatives were reported to act as Multi-Drug Resistance (MDR) modulators that inhibit p-glycoprotein which is responsible for the inability of drugs to enter the cancer cells. Also 1,4-DHPs have antimutagenic properties against chemicals via modulating DNA repair when studied on drosophila. Objective: The objective of this study is the synthesis of bis 1,4-DHPs incorporating ester as well as ether linkages and evaluate the anticancer activity of new compounds for synergistic purpose. Different genetic tools were used in an attempt to know the mechanism of action of this compound against lung cancer. Method: An efficient one pot synthesis of bis 1,4-DHPs using 3-aminocrotononitrile and bis(aldehydes) has been developed. The cytotoxic effect against human cell lines MCF7, and A549 cell lines was evaluated. Results: All compounds exhibited better cytotoxicity toward lung carcinoma cells than breast cancer cells. With respect to lung carcinoma cell line (A549), compound 10 was the most active compound and the three other compounds 7, 8, and 9 showed comparable IC50 values. In case of breast cancer cell line (MCF7), the most active one was compound 7, while compound 8 recorded the least activity. Conclusion: we have developed an efficient method for the synthesis of novel bis 1,4-dihydropyridine derivatives incorporating ester or ether linkage. All compounds showed better cytotoxicity results against A549 than MCF7, so that lung carcinoma cell line was chosen to perform the molecular studies on it. The results showed that all compounds (7, 8, 9 and 10) caused cell cycle arrest at G1 phase. The molecular docking study on CDK2 confirmed the results of cell cycle assay which showed good binding energy between the compounds and the active site of enzyme indicating the inhibition of the enzyme.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yu-An Chen ◽  
Yong-Da Sie ◽  
Tsung-Yun Liu ◽  
Hsiang-Ling Kuo ◽  
Pei-Yi Chou ◽  
...  

AbstractMetastatic cancer cells are frequently deficient in WWOX protein or express dysfunctional WWOX (designated WWOXd). Here, we determined that functional WWOX-expressing (WWOXf) cells migrate collectively and expel the individually migrating WWOXd cells. For return, WWOXd cells induces apoptosis of WWOXf cells from a remote distance. Survival of WWOXd from the cell-to-cell encounter is due to activation of the survival IκBα/ERK/WWOX signaling. Mechanistically, cell surface epitope WWOX286-299 (repl) in WWOXf repels the invading WWOXd to undergo retrograde migration. However, when epitope WWOX7-21 (gre) is exposed, WWOXf greets WWOXd to migrate forward for merge. WWOX binds membrane type II TGFβ receptor (TβRII), and TβRII IgG-pretreated WWOXf greet WWOXd to migrate forward and merge with each other. In contrast, TβRII IgG-pretreated WWOXd loses recognition by WWOXf, and WWOXf mediates apoptosis of WWOXd. The observatons suggest that normal cells can be activated to attack metastatic cancer cells. WWOXd cells are less efficient in generating Ca2+ influx and undergo non-apoptotic explosion in response to UV irradiation in room temperature. WWOXf cells exhibit bubbling cell death and Ca2+ influx effectively caused by UV or apoptotic stress. Together, membrane WWOX/TβRII complex is needed for cell-to-cell recognition, maintaining the efficacy of Ca2+ influx, and control of cell invasiveness.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 462 ◽  
Author(s):  
Joanna Pilch ◽  
Patrycja Kowalik ◽  
Piotr Bujak ◽  
Anna M. Nowicka ◽  
Ewa Augustin

Nanotechnology-based drug delivery provides a promising area for improving the efficacy of cancer treatments. Therefore, we investigate the potential of using quantum dots (QDs) as drug carriers for antitumor unsymmetrical bisacridine derivatives (UAs) to cancer cells. We examine the influence of QD–UA hybrids on the cellular uptake, internalization (Confocal Laser Scanning Microscope), and the biological response (flow cytometry and light microscopy) in lung H460 and colon HCT116 cancer cells. We show the time-dependent cellular uptake of QD–UA hybrids, which were more efficiently retained inside the cells compared to UAs alone, especially in H460 cells, which could be due to multiple endocytosis pathways. In contrast, in HCT116 cells, the hybrids were taken up only by one endocytosis mechanism. Both UAs and their hybrids induced apoptosis in H460 and HCT116 cells (to a greater extent in H460). Cells which did not die underwent senescence more efficiently following QDs–UAs treatment, compared to UAs alone. Cellular senescence was not observed in HCT116 cells following treatment with both UAs and their hybrids. Importantly, QDgreen/red themselves did not provoke toxic responses in cancer or normal cells. In conclusion, QDs are good candidates for targeted UA delivery carriers to cancer cells while protecting normal cells from toxic drug activities.


2021 ◽  
Vol 22 (12) ◽  
pp. 6519
Author(s):  
Yuta Otani ◽  
Ken-ichi Fujita ◽  
Toshiki Kameyama ◽  
Akila Mayeda

Using TSG101 pre-mRNA, we previously discovered cancer-specific re-splicing of mature mRNA that generates aberrant transcripts/proteins. The fact that mRNA is aberrantly re-spliced in various cancer cells implies there must be an important mechanism to prevent deleterious re-splicing on the spliced mRNA in normal cells. We thus postulated that mRNA re-splicing is controlled by specific repressors, and we searched for repressor candidates by siRNA-based screening for mRNA re-splicing activity. We found that knock-down of EIF4A3, which is a core component of the exon junction complex (EJC), significantly promoted mRNA re-splicing. Remarkably, we could recapitulate cancer-specific mRNA re-splicing in normal cells by knock-down of any of the core EJC proteins, EIF4A3, MAGOH, or RBM8A (Y14), implicating the EJC core as the repressor of mRNA re-splicing often observed in cancer cells. We propose that the EJC core is a critical mRNA quality control factor to prevent over-splicing of mature mRNA.


Author(s):  
Erem Ahmetali ◽  
Pinar Sen ◽  
N. Ceren Süer ◽  
Tebello Nyokong ◽  
Tarik Eren ◽  
...  

Author(s):  
Jiaxin Shen ◽  
Dandan Chen ◽  
Ye Liu ◽  
Guoyang Gao ◽  
Zhihe Liu ◽  
...  

Photodynamic therapy (PDT) is a promising method for cancer therapy and also may initiate unexpected damages to normal cells and tissues. Herein, we developed a near-infrared (NIR) light-activatable nanophotosensitizer, which...


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