Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 64
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Cancer Immunol Immunother ; 71(9): 2099-2108, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35032175

ABSTRACT

Conventional cancer therapies such as chemotherapy are non-selective and induce immune system anergy, which lead to serious side effects and tumor relapse. It is a challenge to prime the body's immune system in the cancer-bearing subject to produce cancer antigen-targeting antibodies, as most tumor-associated antigens are expressed abundantly in cancer cells and some of normal cells. This study illustrates how hapten-based pre-immunization (for anti-hapten antibodies production) combined with cancer receptor labeling with hapten antigen constructs can elicit antibody-dependent cellular phagocytosis (ADCP). Thus, the hapten antigen 2,4-dinitrophenol (DNP) was covalently combined with a cancer receptor-binding dipeptide (IYIY) to form a dipeptide-hapten construct (IYIY-DNP, MW = 1322.33) that targets the tropomyosin receptor kinase C (TrkC)-expressed on the surface of metastatic cancer cells. IYIY-DNP facilitated selective association of RAW264.7 macrophages to the TrkC expressing 4T1 cancer cells in vitro, forming cell aggregates in the presence of anti-DNP antibodies, suggesting initiation of anti-DNP antibody-dependent cancer cell recognition of macrophages by the IYIY-DNP. In in vivo, IYIY-DNP at 10 mg/kg suppressed growth of 4T1 tumors in DNP-immunized BALB/c mice by 45% (p < 0.05), when comparing the area under the tumor growth curve to that of the saline-treated DNP-immunized mice. Meanwhile, IYIY-DNP at 10 mg/kg had no effect on TrkC-negative 67NR tumor-bearing mice immunized with DNP. Tumor growth suppression activity of IYIY-DNP in DNP-immunized mice was associated with an increase in the anti-DNP IgG (7.3 × 106 ± 1.6 U/mL) and IgM (0.9 × 106 ± 0.07 U/mL) antibodies after five cycles of DNP treatment, demonstrated potential for hapten-based pre-immunization then treatment with IYIY-DNP to elicit ADCP for improved immunotherapy of TrkC expressing cancers.


Subject(s)
Neoplasm Recurrence, Local , Tropomyosin , Animals , Antibodies , Antibody Formation , Antigens , Carrier Proteins , Dipeptides , Haptens , Immunologic Factors , Immunotherapy , Mice , Phagocytosis
2.
Nutr Cancer ; 73(9): 1780-1791, 2021.
Article in English | MEDLINE | ID: mdl-32875900

ABSTRACT

Curcumin, the yellow pigment derived from turmeric rhizomes, exhibits antioxidant, anti-inflammatory, antimicrobial, and anticancer properties. We have previously reported in a study that curcumin could induce differentiation in embryonal carcinoma cell (EC). EC cells are the primary constituents of teratocarcinoma tumors, and hence differentiating them to a non-proliferative cell type may be useful in anticancer therapies. Here, we conducted a detailed study using various molecular approaches to characterize this differentiation at the cellular and molecular levels. The cells were treated with 20 µM curcumin, which was the optimal concentration to produce the highest amount of differentiated cells. Changes in protein and RNA expression, membrane dynamics, and migration of these cells after treatment with curcumin were then studied in a time-dependent manner. The differentiated cells were morphologically distinct from the precursor cells, and gene expression profiles were altered in curcumin-treated cells. Curcumin promoted cell motility and cell adhesion. Curcumin also induced changes in membrane fluidity and the lateral mobility of lipids in the plasma membrane. The findings of this study suggest that curcumin might have therapeutic potential in differentiation therapy for the treatment of teratocarcinomas or germ cell tumors (GCTs) such as testicular and ovarian GCTs.


Subject(s)
Carcinoma, Embryonal , Curcumin , Cell Differentiation , Curcuma , Curcumin/pharmacology , Embryonal Carcinoma Stem Cells , Humans
3.
Bioconjug Chem ; 29(12): 4149-4159, 2018 12 19.
Article in English | MEDLINE | ID: mdl-30428254

ABSTRACT

Photosensitizing nanogels were obtained through a surfactant-free single-step protocol by using a porphyrin-based cross-linker for stabilizing self-assembled nanosized aggregates of thermoresponsive copolymers. Nanogels with varying amounts of porphyrin retained the singlet oxygen generation ability of the porphyrin core and were also capable of inducing temperature increase upon irradiation at 635 nm. Photoinduced killing efficiency was tested against three cell lines: human breast adenocarcinoma (MDA-MB-231 and MCF7) and pancreatic adenocarcinoma (AsPC-1) cells, and a predominant photodynamic mechanism at 450 nm and a mixed photodynamic and photothermal effect at 635 nm was observed. This innovative access to photosensitizing nanogels is a proof of concept, and opens new perspectives toward the preparation of optimized nanophotosensitizers.


Subject(s)
Gels/chemistry , Nanostructures/chemistry , Porphyrins/chemistry , Surface-Active Agents/chemistry , Cell Line, Tumor , Cross-Linking Reagents/chemistry , Humans , Hyperthermia, Induced/methods , Photochemotherapy/methods
4.
Mol Pharm ; 15(7): 2594-2605, 2018 07 02.
Article in English | MEDLINE | ID: mdl-29763568

ABSTRACT

We previously developed a new zinc(II) phthalocyanine (ZnPc) derivative (Pc 1) conjugated to poly-L-glutamic acid (PGA) (1-PG) to address the limitations of ZnPc as part of an antitumor photodynamic therapy approach, which include hydrophobicity, phototoxicity, and nonselectivity in biodistribution and tumor targeting. During this study, we discovered that 1-PG possessed high near-infrared (NIR) light absorptivity (λmax = 675 nm), good singlet oxygen generation efficiency in an aqueous environment, and enhanced photocytotoxic efficacy and cancer cell uptake in vitro. In the current study, we discovered that 1-PG accumulated in 4T1 mouse mammary tumors, with a retention time of up to 48 h. Furthermore, as part of an antitumor PDT, low dose 1-PG (2 mg of Pc 1 equivalent/kg) induced a greater tumor volume reduction (-74 ± 5%) when compared to high dose ZnPc (8 mg/kg, -50 ± 12%). At higher treatment doses (8 mg of Pc 1 equivalent/kg), 1-PG reduced tumor volume maximally (-91 ± 6%) and suppressed tumor size to a minimal level for up to 15 days. The kidney, liver, and lungs of the mice treated with 1-PG (both low and high doses) were free from 4T1 tumor metastasis at the end of the study. Telemetry-spectral-echocardiography studies also revealed that PGA (65 mg/kg) produced insignificant changes to the cardiovascular physiology of Wistar-Kyoto rats when administered in vivo. Results indicate that PGA displays an excellent cardiovascular safety profile, underlining its suitability for application as a nanodrug carrier in vivo. These current findings indicate the potential of 1-PG as a useful photosensitizer candidate for clinical PDT.


Subject(s)
Indoles/administration & dosage , Nanoconjugates/chemistry , Neoplasms/drug therapy , Organometallic Compounds/administration & dosage , Photochemotherapy/methods , Photosensitizing Agents/administration & dosage , Animals , Cardiotoxicity/diagnostic imaging , Cardiotoxicity/etiology , Cell Line, Tumor/transplantation , Disease Models, Animal , Drug Screening Assays, Antitumor , Echocardiography , Humans , Indoles/adverse effects , Indoles/pharmacokinetics , Male , Mice , Mice, Inbred BALB C , Neoplasms/pathology , Organometallic Compounds/adverse effects , Organometallic Compounds/pharmacokinetics , Photochemotherapy/adverse effects , Photosensitizing Agents/adverse effects , Photosensitizing Agents/pharmacokinetics , Polyglutamic Acid/chemistry , Rats , Rats, Inbred WKY , Tissue Distribution
5.
Photochem Photobiol Sci ; 17(11): 1691-1708, 2018 Nov 01.
Article in English | MEDLINE | ID: mdl-29845993

ABSTRACT

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.


Subject(s)
Antineoplastic Agents/therapeutic use , Boron Compounds/therapeutic use , Neoplasms/drug therapy , Photochemotherapy , Photosensitizing Agents/therapeutic use , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Boron Compounds/chemical synthesis , Boron Compounds/chemistry , Humans , Photosensitizing Agents/chemical synthesis , Photosensitizing Agents/chemistry
6.
J Appl Toxicol ; 37(11): 1268-1285, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28165137

ABSTRACT

While nano-sized construct (NSC) use in medicine has grown significantly in recent years, reported unwanted side effects have raised safety concerns. However, the toxicity of NSCs to the cardiovascular system (CVS) and the relative merits of the associated evaluation methods have not been thoroughly studied. This review discusses the toxicological profiles of selected NSCs and provides an overview of the assessment methods, including in silico, in vitro, ex vivo and in vivo models and how they are related to CVS toxicity. We conclude the review by outlining the merits of telemetry coupled with spectral analysis, baroreceptor reflex sensitivity analysis and echocardiography as an appropriate integrated strategy for the assessment of the acute and chronic impact of NSCs on the CVS. Copyright © 2017 John Wiley & Sons, Ltd.


Subject(s)
Baroreflex/drug effects , Cardiovascular Diseases/chemically induced , Cardiovascular Diseases/diagnosis , Cardiovascular System/drug effects , Nanomedicine/methods , Nanoparticles/toxicity , Telemetry , Algorithms , Animals , Blood Pressure/drug effects , Cardiovascular Diseases/physiopathology , Cardiovascular System/physiopathology , Heart Rate/drug effects , Humans , Nanoparticles/chemistry , Predictive Value of Tests , Risk Assessment , Risk Factors , Signal Processing, Computer-Assisted
7.
Nanomedicine ; 13(4): 1447-1458, 2017 05.
Article in English | MEDLINE | ID: mdl-28214608

ABSTRACT

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 λmax 675nm 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.


Subject(s)
Glutamic Acid/chemistry , Indoles/chemistry , Nanoconjugates/chemistry , Photochemotherapy , Photosensitizing Agents/chemistry , Animals , Cell Line, Tumor , Endocytosis , Isoindoles , Light , Mice , Molecular Structure , Singlet Oxygen/chemistry
8.
Molecules ; 21(7)2016 Jul 22.
Article in English | MEDLINE | ID: mdl-27455222

ABSTRACT

A series of 2'-hydroxy- and 2'-hydroxy-4',6'-dimethoxychalcones was synthesised and evaluated as inhibitors of human acetylcholinesterase (AChE). The majority of the compounds were found to show some activity, with the most active compounds having IC50 values of 40-85 µM. Higher activities were generally observed for compounds with methoxy substituents in the A ring and halogen substituents in the B ring. Kinetic studies on the most active compounds showed that they act as mixed-type inhibitors, in agreement with the results of molecular modelling studies, which suggested that they interact with residues in the peripheral anionic site and the gorge region of AChE.


Subject(s)
Chalcones/chemistry , Chalcones/pharmacology , Cholinesterase Inhibitors/chemistry , Cholinesterase Inhibitors/pharmacology , Models, Molecular , Acetylcholinesterase/metabolism , Binding Sites , Chalcones/chemical synthesis , Chemistry Techniques, Synthetic , Cholinesterase Inhibitors/chemical synthesis , Enzyme Activation/drug effects , Humans , Hydrogen Bonding , Hydrolysis , Molecular Conformation , Molecular Docking Simulation , Molecular Dynamics Simulation , Molecular Structure , Protein Binding , Structure-Activity Relationship
9.
Mol Pharm ; 12(1): 212-22, 2015 Jan 05.
Article in English | MEDLINE | ID: mdl-25487316

ABSTRACT

This contribution features a small molecule that binds TrkC (tropomyosin receptor kinase C) receptor that tends to be overexpressed in metastatic breast cancer cells but not in other breast cancer cells. A sensitizer for (1)O2 production conjugated to this structure gives 1-PDT for photodynamic therapy. Isomeric 2-PDT does not bind TrkC and was used as a control throughout; similarly, TrkC- cancer cells were used to calibrate enhanced killing of TrkC+ cells. Ex vivo, 1- and 2-PDT where only cytotoxic when illuminated, and 1-PDT, gave higher cell death for TrkC+ breast cancer cells. A 1 h administration-to-illumination delay gave optimal TrkC+/TrkC--photocytotoxicity, and distribution studies showed the same delay was appropriate in vivo. In Balb/c mice, a maximum tolerated dose of 20 mg/kg was determined for 1-PDT. 1- and 2-PDT (single, 2 or 10 mg/kg doses and one illumination, throughout) had similar effects on implanted TrkC- tumors, and like those of 2-PDT on TrkC+ tumors. In contrast, 1-PDT caused dramatic TrkC+ tumor volume reduction (96% from initial) relative to the TrkC- tumors or 2-PDT in TrkC+ models. Moreover, 71% of the mice treated with 10 mg/kg 1-PDT (n = 7) showed full tumor remission and survived until 90 days with no metastasis to key organs.


Subject(s)
Antineoplastic Agents/administration & dosage , Boron Compounds/chemistry , Breast Neoplasms/radiotherapy , Gene Expression Regulation, Neoplastic , Photochemotherapy/methods , Receptor, trkC/metabolism , Animals , Boron Compounds/therapeutic use , Cell Line, Tumor , Cell Survival , Female , Humans , Maximum Tolerated Dose , Mice , Mice, Inbred BALB C , Microscopy, Fluorescence , Neoplasm Metastasis , Neoplasm Transplantation , Permeability , Photosensitizing Agents/chemistry , Photosensitizing Agents/therapeutic use , Remission Induction
10.
Small ; 10(24): 4993-5013, 2014 Dec 29.
Article in English | MEDLINE | ID: mdl-25164105

ABSTRACT

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?


Subject(s)
Nanostructures , Neoplasms/drug therapy , Photochemotherapy , Photosensitizing Agents/therapeutic use , Animals , Disease Models, Animal , Liposomes , Micelles , Photosensitizing Agents/chemistry , Polymers/chemistry
11.
Mol Pharm ; 11(9): 3164-73, 2014 Sep 02.
Article in English | MEDLINE | ID: mdl-25077598

ABSTRACT

This study aims to improve the photodynamic properties and biological effectiveness of 15(1)-hydroxypurpurin-7-lactone dimethyl ester (G2), a semisynthetic photosensitizer, for the PDT treatment of cancer. The strategy we undertook was by conjugating G2 with aspartic acid and lysine amino acid moieties. The photophysical properties, singlet oxygen generation, distribution coefficiency (Log D in octanol/PBS pH 7.4), and photostability of these analogues and their in vitro bioactivities such as cellular uptake, intracellular localization, and photoinduced cytotoxicity were evaluated. In addition, selected analogues were also investigated for their PDT-induced vasculature occlusion in the chick chorioallantoic membrane model and for their antitumor efficacies in Balb/C mice bearing 4T1 mouse mammary tumor. From the study, conjugation with aspartic acid improved the aqueous solubility of G2 without affecting its photophysical characteristics. G2-Asp showed similar in vitro and in vivo antitumor efficacies compared to the parent compound. Given the hydrophilic nature of G2-Asp, the photosensitizer is a pharmaceutically advantageous candidate as it can be formulated easily for systemic administration and has reduced risk of aggregation in vascular system.


Subject(s)
Amino Acids/chemistry , Amino Acids/pharmacology , Lactones/chemistry , Lactones/pharmacology , Porphyrins/chemistry , Porphyrins/pharmacology , Animals , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Female , Humans , Mammary Neoplasms, Animal/drug therapy , Mice , Mice, Inbred BALB C , Photochemotherapy/methods , Photosensitizing Agents/chemistry , Photosensitizing Agents/pharmacology , Singlet Oxygen/chemistry , Singlet Oxygen/pharmacology , Tumor Cells, Cultured
12.
Chem Soc Rev ; 42(1): 77-88, 2013 Jan 07.
Article in English | MEDLINE | ID: mdl-23014776

ABSTRACT

BODIPY dyes tend to be highly fluorescent, but their emissions can be attenuated by adding substituents with appropriate oxidation potentials. Substituents like these have electrons to feed into photoexcited BODIPYs, quenching their fluorescence, thereby generating relatively long-lived triplet states. Singlet oxygen is formed when these triplet states interact with (3)O(2). In tissues, this causes cell damage in regions that are illuminated, and this is the basis of photodynamic therapy (PDT). The PDT agents that are currently approved for clinical use do not feature BODIPYs, but there are many reasons to believe that this situation will change. This review summarizes the attributes of BODIPY dyes for PDT, and in some related areas.


Subject(s)
Boron Compounds/chemistry , Fluorescent Dyes/chemistry , Photochemotherapy , Photosensitizing Agents/chemistry
13.
Molecules ; 19(2): 2588-601, 2014 Feb 24.
Article in English | MEDLINE | ID: mdl-24566323

ABSTRACT

Bacopa monnieri and the constituents of this plant, especially bacosides, possess various neuropharmacological properties. Like drugs, some herbal extracts and the constituents of their extracts alter cytochrome P450 (CYP) enzymes, causing potential herb-drug interactions. The effects of Bacopa monnieri standardized extract and the bacosides from the extract on five major CYP isoforms in vitro were analyzed using a luminescent CYP recombinant human enzyme assay. B. monnieri extract exhibited non-competitive inhibition of CYP2C19 (IC50/Ki = 23.67/9.5 µg/mL), CYP2C9 (36.49/12.5 µg/mL), CYP1A2 (52.20/25.1 µg/mL); competitive inhibition of CYP3A4 (83.95/14.5 µg/mL) and weak inhibition of CYP2D6 (IC50 = 2061.50 µg/mL). However, the bacosides showed negligible inhibition of the same isoforms. B. monnieri, which is orally administered, has a higher concentration in the gut than the liver; therefore, this herb could exhibit stronger inhibition of intestinal CYPs than hepatic CYPs. At an estimated gut concentration of 600 µg/mL (based on a daily dosage of 300 mg/day), B. monnieri reduced the catalytic activities of CYP3A4, CYP2C9 and CYP2C19 to less than 10% compared to the total activity (without inhibitor = 100%). These findings suggest that B. monnieri extract could contribute to herb-drug interactions when orally co-administered with drugs metabolized by CYP1A2, CYP3A4, CYP2C9 and CYP2C19.


Subject(s)
Aryl Hydrocarbon Hydroxylases/antagonists & inhibitors , Cytochrome P-450 CYP1A2 Inhibitors , Cytochrome P-450 CYP2D6 Inhibitors , Cytochrome P-450 CYP3A Inhibitors , Cytochrome P-450 Enzyme Inhibitors , Bacopa/chemistry , Cytochrome P-450 CYP1A2/metabolism , Cytochrome P-450 CYP2C19 , Cytochrome P-450 CYP2D6/metabolism , Cytochrome P-450 CYP3A/metabolism , Cytochrome P-450 Enzyme System/metabolism , Herb-Drug Interactions , Humans , Inactivation, Metabolic , Microsomes, Liver/metabolism , Plant Extracts/administration & dosage , Plant Extracts/chemistry , Saponins/administration & dosage , Triterpenes/administration & dosage
14.
Molecules ; 19(7): 8933-48, 2014 Jun 27.
Article in English | MEDLINE | ID: mdl-24979399

ABSTRACT

Muscarinic acetylcholine receptor-active compounds have potential for the treatment of Alzheimer's disease. In this study, a series of natural and synthetic flavones and flavonols was assayed in vitro for their ability to inhibit radioligand binding at human cloned M1 muscarinic receptors. Several compounds were found to possess competitive binding affinity (Ki=40-110 µM), comparable to that of acetylcholine (Ki=59 µM). Despite the fact that these compounds lack a positively-charged ammonium group under physiological conditions, molecular modelling studies suggested that they bind to the orthosteric site of the receptor, mainly through non-polar interactions.


Subject(s)
Flavones/chemistry , Muscarinic Agonists/chemistry , Receptor, Muscarinic M1/chemistry , Animals , Binding Sites , Molecular Docking Simulation , Protein Binding , Protein Structure, Secondary , Protein Structure, Tertiary , Rats
15.
Int J Nanomedicine ; 19: 3697-3714, 2024.
Article in English | MEDLINE | ID: mdl-38681091

ABSTRACT

Introduction: Over 75% of clinical microbiological infections are caused by bacterial biofilms that grow on wounds or implantable medical devices. This work describes the development of a new poly(diallyldimethylammonium chloride) (PDADMAC)/alginate-coated gold nanorod (GNR/Alg/PDADMAC) that effectively disintegrates the biofilms of Staphylococcus aureus (S. aureus), a prominent pathogen responsible for hospital-acquired infections. Methods: GNR was synthesised via seed-mediated growth method, and the resulting nanoparticles were coated first with Alg and then PDADMAC. FTIR, zeta potential, transmission electron microscopy, and UV-Vis spectrophotometry analysis were performed to characterise the nanoparticles. The efficacy and speed of the non-coated GNR and GNR/Alg/PDADMAC in disintegrating S. aureus-preformed biofilms, as well as their in vitro biocompatibility (L929 murine fibroblast) were then studied. Results: The synthesised GNR/Alg/PDADMAC (mean length: 55.71 ± 1.15 nm, mean width: 23.70 ± 1.13 nm, aspect ratio: 2.35) was biocompatible and potent in eradicating preformed biofilms of methicillin-resistant (MRSA) and methicillin-susceptible S. aureus (MSSA) when compared to triclosan, an antiseptic used for disinfecting S. aureus colonisation on abiotic surfaces in the hospital. The minimum biofilm eradication concentrations of GNR/Alg/PDADMAC (MBEC50 for MRSA biofilm = 0.029 nM; MBEC50 for MSSA biofilm = 0.032 nM) were significantly lower than those of triclosan (MBEC50 for MRSA biofilm = 10,784 nM; MBEC50 for MRSA biofilm 5967 nM). Moreover, GNR/Alg/PDADMAC was effective in eradicating 50% of MRSA and MSSA biofilms within 17 min when used at a low concentration (0.15 nM), similar to triclosan at a much higher concentration (50 µM). Disintegration of MRSA and MSSA biofilms was confirmed by field emission scanning electron microscopy and confocal laser scanning microscopy. Conclusion: These findings support the potential application of GNR/Alg/PDADMAC as an alternative agent to conventional antiseptics and antibiotics for the eradication of medically important MRSA and MSSA biofilms.


Subject(s)
Alginates , Anti-Bacterial Agents , Biofilms , Gold , Nanotubes , Polyethylenes , Quaternary Ammonium Compounds , Staphylococcus aureus , Biofilms/drug effects , Gold/chemistry , Gold/pharmacology , Quaternary Ammonium Compounds/chemistry , Quaternary Ammonium Compounds/pharmacology , Alginates/chemistry , Alginates/pharmacology , Nanotubes/chemistry , Animals , Mice , Staphylococcus aureus/drug effects , Staphylococcus aureus/physiology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Polyethylenes/chemistry , Polyethylenes/pharmacology , Staphylococcal Infections/drug therapy , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/physiology , Cell Line , Microbial Sensitivity Tests , Metal Nanoparticles/chemistry
16.
J Control Release ; 359: 268-286, 2023 07.
Article in English | MEDLINE | ID: mdl-37244297

ABSTRACT

Monospecific antibodies have been utilised increasingly for anti-cancer drug targeting owing to their ability to minimise off-target toxicity by binding specifically to a tumour epitope, hence selectively delivering drugs to the tumour cells. Nevertheless, the monospecific antibodies only engage a single cell surface epitope to deliver their drug payload. Hence, their performance is often unsatisfactory in cancers where multiple epitopes need to be engaged for optimal cellular internalisation. In this context, bispecific antibodies (bsAbs) that simultaneously target two distinct antigens or two distinct epitopes of the same antigen offer a promising alternative in antibody-based drug delivery. This review describes the recent advances in developing bsAb-based drug delivery strategies, encompassing the direct conjugation of drug to bsAbs to form bispecific antibody-drug conjugates (bsADCs) and the surface functionalisation of nanoconstructs with bsAbs to form bsAb-coupled nanoconstructs. The article first details the roles of bsAbs in enhancing the internalisation and intracellular trafficking of bsADCs with subsequent release of chemotherapeutic drugs for an augmented therapeutic efficacy, particularly among heterogeneous tumour cell populations. Then, the article discusses the roles of bsAbs in facilitating the delivery of drug-encapsulating nanoconstructs, including organic/inorganic nanoparticles and large bacteria-derived minicells, that provide a larger drug loading capacity and better stability in blood circulation than bsADCs. The limitations of each type of bsAb-based drug delivery strategy and the future prospects of more versatile strategies (e.g., trispecific antibodies, autonomous drug delivery systems, theranostics) are also elaborated.


Subject(s)
Antibodies, Bispecific , Antineoplastic Agents , Immunoconjugates , Neoplasms , Humans , Antibodies, Bispecific/therapeutic use , Antineoplastic Agents/therapeutic use , Neoplasms/therapy , Antigens , Immunoconjugates/therapeutic use , Epitopes
17.
Ultrason Sonochem ; 96: 106437, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37187119

ABSTRACT

Sonodynamic therapy (SDT) emerges as a promising non-invasive alternative for eradicating malignant tumours. However, its therapeutic efficacy remains limited due to the lack of sonosensitisers with high potency and biosafety. Previously, gold nanorods (AuNRs) have been extensively studied for their applications in photodynamic or photothermal cancer therapy, but their sonosensitising properties are largely unexplored. Here, we reported the applicability of alginate-coated AuNRs (AuNRsALG) with improved biocompatibility profiles as promising nanosonosensitisers for SDT for the first time. AuNRsALG were found stable under ultrasound irradiation (1.0 W/cm2, 5 min) and maintained structural integrity for 3 cycles of irradiation. The exposure of the AuNRsALG to ultrasound irradiation (1.0 W/cm2, 5 min) was shown to enhance the cavitation effect significantly and generate a 3 to 8-fold higher amount of singlet oxygen (1O2) than other reported commercial titanium dioxide nanosonosensitisers. AuNRsALG exerted dose-dependent sonotoxicity on human MDA-MB-231 breast cancer cells in vitro, with âˆ¼ 81% cancer cell killing efficacy at a sub-nanomolar level (IC50 was 0.68 nM) predominantly through apoptosis. The protein expression analysis showed significant DNA damage and downregulation of anti-apoptotic Bcl-2, suggesting AuNRsALG induced cell death through the mitochondrial pathway. The addition of mannitol, a reactive oxygen species (ROS) scavenger, inhibited cancer-killing effect of AuNRsALG-mediated SDT, further verifying that the sonotoxicity of AuNRsALG is driven by the production of ROS. Overall, these results highlight the potential application of AuNRsALG as an effective nanosonosensitising agent in clinical settings.


Subject(s)
Nanotubes , Neoplasms , Humans , Reactive Oxygen Species/metabolism , Alginates , Gold/pharmacology , Gold/chemistry , Neoplasms/drug therapy , Nanotubes/chemistry , Cell Line, Tumor
18.
Molecules ; 17(3): 2408-27, 2012 Feb 28.
Article in English | MEDLINE | ID: mdl-22374313

ABSTRACT

Alzheimer's disease (AD) is the most common form of dementia among older people and the pathogenesis of this disease is associated with oxidative stress. Acetylcholinesterase inhibitors with antioxidant activities are considered potential treatments for AD. Some novel ketone derivatives of gallic hydrazide-derived Schiff bases were synthesized and examined for their antioxidant activities and in vitro and in silico acetyl cholinesterase inhibition. The compounds were characterized using spectroscopy and X-ray crystallography. The ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays revealed that all the compounds have strong antioxidant activities. N-(1-(5-bromo-2-hydroxyphenyl)-ethylidene)-3,4,5-trihydroxybenzohydrazide (2) was the most potent inhibitor of human acetyl cholinesterase, giving an inhibition rate of 77% at 100 µM. Molecular docking simulation of the ligand-enzyme complex suggested that the ligand may be positioned in the enzyme's active-site gorge, interacting with residues in the peripheral anionic subsite (PAS) and acyl binding pocket (ABP). The current work warrants further preclinical studies to assess the potential for these novel compounds for the treatment of AD.


Subject(s)
Cholinesterase Inhibitors/chemical synthesis , Free Radical Scavengers/chemical synthesis , Hydrazines/chemical synthesis , Ketones/chemical synthesis , Schiff Bases/chemical synthesis , Acetylcholinesterase/chemistry , Amino Acid Motifs , Binding Sites , Cholinesterase Inhibitors/chemistry , Crystallography, X-Ray , Free Radical Scavengers/chemistry , Humans , Hydrazines/chemistry , Hydrogen Bonding , Hydrophobic and Hydrophilic Interactions , Ketones/chemistry , Models, Molecular , Molecular Conformation , Molecular Structure , Schiff Bases/chemistry
19.
Macromol Biosci ; 22(8): e2200130, 2022 08.
Article in English | MEDLINE | ID: mdl-35579182

ABSTRACT

A critical factor in developing an efficient photosensitizer-gold nanoparticle (PS-AuNP) hybrid system with improved plasmonic photosensitization is to allocate a suitable space between AuNPs and PS. Poly(amidoamine) (PAMAM) dendrimer is selected as a spacer between the PS and confeito-like gold nanoparticles (confeito-AuNPs), providing the required distance (≈2.5-22.5 nm) for plasmon-enhanced singlet oxygen generation and heat production upon 638-nm laser irradiation and increase the cellular internalization of the nanoconjugates. The loading of the PS, tetrakis(4-carboxyphenyl) porphyrin (TCPP), and modified zinc phthalocyanine (ZnPc1) onto PAMAM-confeito-AuNPs demonstrate better in vitro cancer cell-killing efficacy, as the combined photothermal-photodynamic therapies (PTT-PDTs) outperforms the single treatment modalities (PTT or PDT alone). These PS-PAMAM-confeito-AuNPs also demonstrate higher phototoxicity than photosensitizers directly conjugated to confeito-AuNPs (TCPP-confeito-AuNPs and ZnPc1-confeito-AuNPs) against all breast cancer cell lines tested (MDA-MB-231, MCF7, and 4T1). In the in vivo studies, TCPP-PAMAM-confeito-AuNPs are biocompatible and exhibit a selective tumor accumulation effect, resulting in higher antitumor efficacy than free TCPP, PAMAM-confeito-AuNPs, and TCPP-confeito-AuNPs. In vitro and in vivo evaluations confirm PAMAM effectiveness in facilitating cellular uptake, plasmon-enhanced singlet oxygen and heat generation. In summary, this study highlights the potential of integrating a PAMAM spacer in enhancing the plasmon effect-based photothermal-photodynamic anticancer treatment efficiency of PS-decorated confeito-AuNPs.


Subject(s)
Dendrimers , Metal Nanoparticles , Nanoparticles , Neoplasms , Photochemotherapy , Dendrimers/pharmacology , Gold/pharmacology , Neoplasms/drug therapy , Photochemotherapy/methods , Photosensitizing Agents/pharmacology , Singlet Oxygen/metabolism
20.
Int J Nanomedicine ; 17: 137-150, 2022.
Article in English | MEDLINE | ID: mdl-35046650

ABSTRACT

PURPOSE: The use of nanocarriers to improve the delivery and efficacy of antimetastatic agents is less explored when compared to cytotoxic agents. This study reports the entrapment of an antimetastatic Signal Transducer and Activator of Transcription 3 (STAT3) dimerization blocker, Stattic (S) into a chitosan-coated-poly(lactic-co-glycolic acid) (C-PLGA) nanocarrier and the improvement on the drug's physicochemical, in vitro and in vivo antimetastatic properties post entrapment. METHODS: In vitro, physicochemical properties of the Stattic-entrapped C-PLGA nanoparticles (S@C-PLGA) and Stattic-entrapped PLGA nanoparticles (S@PLGA, control) in terms of size, zeta potential, polydispersity index, drug loading, entrapment efficiency, Stattic release in different medium and cytotoxicity were firstly evaluated. The in vitro antimigration properties of the nanoparticles on breast cancer cell lines were then studied by Scratch assay and Transwell assay. Study on the in vivo antitumor efficacy and antimetastatic properties of S@C-PLGA compared to Stattic were then performed on 4T1 tumor bearing mice. RESULTS: The S@C-PLGA nanoparticles (141.8 ± 2.3 nm) was hemocompatible and exhibited low Stattic release (12%) in plasma. S@C-PLGA also exhibited enhanced in vitro anti-cell migration potency (by >10-fold in MDA-MB-231 and 5-fold in 4T1 cells) and in vivo tumor growth suppression (by 33.6%) in 4T1 murine metastatic mammary tumor bearing mice when compared to that of the Stattic-treated group. Interestingly, the number of lung and liver metastatic foci was found to reduce by 50% and 56.6%, respectively, and the average size of the lung metastatic foci was reduced by 75.4% in 4T1 tumor-bearing mice treated with S@C-PLGA compared to Stattic-treated group (p < 0.001). CONCLUSION: These findings suggest the usage of C-PLGA nanocarrier to improve the delivery and efficacy of antimetastatic agents, such as Stattic, in cancer therapy.


Subject(s)
Chitosan , Nanoparticles , Animals , Cyclic S-Oxides , Dimerization , Drug Carriers , Humans , Mice , Polyglycolic Acid , Polylactic Acid-Polyglycolic Acid Copolymer , STAT3 Transcription Factor
SELECTION OF CITATIONS
SEARCH DETAIL