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Rustad EAL, von Hofsten S, Kumar R, Lænsman EA, Berge G, Škalko-Basnet N. The pH-Responsive Liposomes-The Effect of PEGylation on Release Kinetics and Cellular Uptake in Glioblastoma Cells. Pharmaceutics 2022; 14. [PMID: 35745698 DOI: 10.3390/pharmaceutics14061125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/14/2022] [Accepted: 05/23/2022] [Indexed: 12/02/2022] Open
Abstract
Nanomedicine has been, to a certain degree, a success story in the development of superior anticancer therapies. However, there are tumors that remain a huge challenge for nanoformulations, for instance, brain tumors such as glioblastoma, the most common and aggressive brain tumor. To utilize the fact that such tumors are characterized by an acidic extracellular environment, we selected pH-responsive liposomes as a potential drug delivery system for superior delivery to GBM. Liposomes comprising PEGylated lipid of two chain lengths with encapsulated fluorescent marker calcein were characterized and challenged against non-PEGylated vesicles. The in vitro calcein release from three liposomal formulations (<200 nm), namely non-PEGylated (pH-Lip) and PEGylated, pH-Lip−PEG750, and pH-Lip−PEG2000, was followed at three pH conditions to prove the pH-responsiveness. The intracellular delivery of a liposomally encapsulated marker was determined in GL261 glioblastoma cell lines in vitro using both flow cytometry and confocal microscopy. The inclusion of PEG2000 within liposomal formulation resulted in reduced in vitro pH-responsiveness compared to pH-Lip and pH-Lip750. All three pH-responsive liposomal formulations improved intracellular uptake in GL261 cells compared to non-pH-responsive liposomes, with negligible differences regarding PEG length. The proposed formulations should be further evaluated in glioblastoma models.
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García MC, Calderón-Montaño JM, Rueda M, Longhi M, Rabasco AM, López-Lázaro M, Prieto-Dapena F, González-Rodríguez ML. pH-temperature dual-sensitive nucleolipid-containing stealth liposomes anchored with PEGylated AuNPs for triggering delivery of doxorubicin. Int J Pharm 2022; 619:121691. [PMID: 35331830 DOI: 10.1016/j.ijpharm.2022.121691] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 03/05/2022] [Accepted: 03/18/2022] [Indexed: 11/29/2022]
Abstract
Liposomes (Lip) are useful nanocarriers for drug delivery and cancer nanomedicine because of their ability to efficiently encapsulate drugs with different physical and chemical properties. The pH gradient between normal and tumoral tissues, and their rapid metabolism that induces hyperthermia encourage the development of pH- and thermo-sensitive Lip for delivering anticancer drugs. Nucleolipids have been studied as scaffolding material to prepare Lip, mainly for cancer therapy. Herein, we report for the first time the use of 1,2-dipalmitoyl-sn-glycero-3-(cytidine diphosphate) (DG-CDP) to develop pH/thermo-sensitive nucleolipid-containing stealth Lip stabilized by combination with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and cholesterol, anchored with NH2-PEGylated gold nanoparticles (PEG-AuNPs, 15 nm) for triggering delivery of doxorubicin (Dox). The optimal composition of DPPC, DG-CDP and cholesterol (94:3:3) was established by Langmuir isotherms. Unloaded and Dox-loaded Lip and AuNPs-Lip exhibited nano-scale sizes (415-650 nm), acceptable polydispersity indexes (<0.33), spherical shapes, and negative Z-potential (-23- -6.6 mV) due to the phosphate groups of DG-CDP, which allowed the anchoring with positively charged AuNPs. High EE% were achieved (>78%) and although efficient control in the Dox release towards different receptor media was observed, the release of Dox from PEG-AuNPs-Lip-Dox was significantly triggered at acidic pH and hyperthermia temperature, demonstrating its responsiveness to both stimuli. Dox-loaded Lip showed high cytotoxic activity against MDA-MB-231 breast cancer cells and SK-OV-3 ovarian cancer cells, suggesting that Dox was released from these nanocarriers over time. Overall, the liposomal formulations showed promising properties as stimuli-responsive nanocarriers for cancer nanomedicine, with prospects for hyperthermia therapy.
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Affiliation(s)
- Mónica C García
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Ciencias Farmacéuticas, Ciudad Universitaria, Haya de la Torre and Medina Allende, Science Building 2, Córdoba X5000HUA, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, CONICET, Unidad de Investigación y Desarrollo en Tecnología Farmacéutica, UNITEFA, Córdoba X5000HUA, Argentina; Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Universidad de Sevilla, C/Prof. García González 2, 41012 Seville, Spain.
| | - José Manuel Calderón-Montaño
- Department of Pharmacology, Faculty of Pharmacy, Universidad de Sevilla, C/Prof. García González 2, 41012 Seville, Spain
| | - Manuela Rueda
- Department of Physical Chemistry, Faculty of Chemistry, Universidad de Sevilla, C/Prof. García González s/n, 41012 Seville, Spain
| | - Marcela Longhi
- Universidad Nacional de Córdoba, Facultad de Ciencias Químicas, Departamento de Ciencias Farmacéuticas, Ciudad Universitaria, Haya de la Torre and Medina Allende, Science Building 2, Córdoba X5000HUA, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas, CONICET, Unidad de Investigación y Desarrollo en Tecnología Farmacéutica, UNITEFA, Córdoba X5000HUA, Argentina
| | - Antonio M Rabasco
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Universidad de Sevilla, C/Prof. García González 2, 41012 Seville, Spain
| | - Miguel López-Lázaro
- Department of Pharmacology, Faculty of Pharmacy, Universidad de Sevilla, C/Prof. García González 2, 41012 Seville, Spain
| | - Francisco Prieto-Dapena
- Department of Physical Chemistry, Faculty of Chemistry, Universidad de Sevilla, C/Prof. García González s/n, 41012 Seville, Spain
| | - María Luisa González-Rodríguez
- Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Universidad de Sevilla, C/Prof. García González 2, 41012 Seville, Spain.
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Shah H, Madni A, Khan MM, Ahmad FU, Jan N, Khan S, Rahim MA, Khan S, Ali MM, Kazi M. pH-Responsive Liposomes of Dioleoyl Phosphatidylethanolamine and Cholesteryl Hemisuccinate for the Enhanced Anticancer Efficacy of Cisplatin. Pharmaceutics 2022; 14:129. [PMID: 35057025 DOI: 10.3390/pharmaceutics14010129] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/11/2021] [Accepted: 12/31/2021] [Indexed: 01/27/2023] Open
Abstract
The current study aimed to develop pH-responsive cisplatin-loaded liposomes (CDDP@PLs) via the thin film hydration method. Formulations with varied ratios of dioleoyl phosphatidylethanolamine (DOPE) to cholesteryl hemisuccinate (CHEMS) were investigated to obtain the optimal particle size, zeta potential, entrapment efficiency, in vitro release profile, and stability. The particle size of the CDDP@PLs was in the range of 153.2 ± 3.08–206.4 ± 2.26 nm, zeta potential was −17.8 ± 1.26 to −24.6 ± 1.72, and PDI displayed an acceptable size distribution. Transmission electron microscopy revealed a spherical shape with ~200 nm size. Fourier transform infrared spectroscopic analysis showed the physicochemical stability of CDDP@PLs, and differential scanning calorimetry analysis showed the loss of the crystalline nature of cisplatin in liposomes. In vitro release study of CDDP@PLs at pH 7.4 depicted the lower release rate of cisplatin (less than 40%), and at a pH of 6.5, an almost 65% release rate was achieved compared to the release rate at pH 5.5 (more than 80%) showing the tumor-specific drug release. The cytotoxicity study showed the improved cytotoxicity of CDDP@PLs compared to cisplatin solution in MDA-MB-231 and SK-OV-3 cell lines, and fluorescence microscopy also showed enhanced cellular internalization. The acute toxicity study showed the safety and biocompatibility of the developed carrier system for the potential delivery of chemotherapeutic agents. These studies suggest that CDDP@PLs could be utilized as an efficient delivery system for the enhancement of therapeutic efficacy and to minimize the side effects of chemotherapy by releasing cisplatin at the tumor site.
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Antoniou AI, Giofrè S, Seneci P, Passarella D, Pellegrino S. Stimulus-responsive liposomes for biomedical applications. Drug Discov Today 2021; 26:1794-824. [PMID: 34058372 DOI: 10.1016/j.drudis.2021.05.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/01/2021] [Accepted: 05/17/2021] [Indexed: 02/08/2023]
Abstract
Liposomes are amphipathic lipidic supramolecular aggregates that are able to encapsulate and carry molecules of both hydrophilic and hydrophobic nature. They have been widely used as in vivo drug delivery systems for some time because they offer features such as synthetic flexibility, biodegradability, biocompatibility, low immunogenicity, and negligible toxicity. In recent years, the chemical modification of liposomes has paved the way to the development of smart liposome-based drug delivery systems, which are characterized by even more tunable and disease-directed features. In this review, we highlight the different types of chemical modification introduced to date, with a particular focus on internal stimuli-responsive liposomes and prodrug activation.
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Zhang N, Tan Y, Yan L, Zhang C, Xu M, Guo H, Zhuang B, Zhou L, Xie X. Modulation of Tumor Hypoxia by pH-Responsive Liposomes to Inhibit Mitochondrial Respiration for Enhancing Sonodynamic Therapy. Int J Nanomedicine 2020; 15:5687-5700. [PMID: 32821097 PMCID: PMC7418152 DOI: 10.2147/ijn.s256038] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 07/17/2020] [Indexed: 01/04/2023] Open
Abstract
Background and Purpose Sonodynamic therapy (SDT) has been widely used for the noninvasive treatment of solid tumors, but the hypoxic tumor microenvironment limits its therapeutic effect. The current methods of reoxygenation to enhance SDT have limitations, prompting reconsideration of the design of therapeutic approaches. Here, we developed a tumor microenvironment-responsive nanoplatform by reducing oxygen consumption to overcome hypoxia-induced resistance to cancer therapy. Methods A pH-responsive drug-loaded liposome (MI-PEOz-lip) was prepared and used to reduce oxygen consumption, attenuating hypoxia-induced resistance to SDT and thereby improving therapeutic efficiency. Photoacoustic imaging (PAI) and fluorescence imaging (FI) of MI-PEOz-lip were evaluated in vitro and in breast xenograft tumor models. The pH-sensitive functionality of MI-PEOz-lip was applied for pH-triggered cargo release, and its capacity was evaluated. The MI-PEOz-lip-mediated SDT effect was compared with other treatments in vivo. Results MI-PEOz-lip was demonstrated to specifically accumulate in tumors. Metformin molecules in liposomes selectively accumulate in tumors by pH-responsive drug release to inhibit the mitochondrial respiratory chain while releasing IR780 to the tumor area. These pH-responsive liposomes demonstrated PAI and FI imaging capabilities in vitro and in vivo, providing potential for treatment guidance and monitoring. In particular, the prepared MI-PEOz-lip combined with ultrasound irradiation effectively inhibited breast tumors by producing toxic reactive singlet oxygen species (ROS), while the introduction of metformin inhibited mitochondrial respiration and reduced tumor oxygen consumption, resulting in excellent sonodynamic therapy performance compared with other treatments. Conclusion In this study, we present a novel strategy to achieve high therapeutic efficacy of SDT by the rational design of multifunctional nanoplatforms. This work provides a new strategy that can solve the current problems of inefficient oxygen delivery strategies and weaken resistance to various oxygen-dependent therapies.
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Affiliation(s)
- Nan Zhang
- Department of Medical Ultrasonics, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, People's Republic of China
| | - Yang Tan
- Department of Medical Ultrasonics, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, People's Republic of China
| | - Liwei Yan
- Department of Microsurgery and Orthopedic Trauma, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, People's Republic of China
| | - Chunyang Zhang
- Department of Medical Ultrasonics, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, People's Republic of China
| | - Ming Xu
- Department of Medical Ultrasonics, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, People's Republic of China
| | - Huanling Guo
- Department of Medical Ultrasonics, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, People's Republic of China
| | - Bowen Zhuang
- Department of Medical Ultrasonics, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, People's Republic of China
| | - Luyao Zhou
- Department of Medical Ultrasonics, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, People's Republic of China
| | - Xiaoyan Xie
- Department of Medical Ultrasonics, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, People's Republic of China
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Barattin M, Mattarei A, Balasso A, Paradisi C, Cantù L, Del Favero E, Viitala T, Mastrotto F, Caliceti P, Salmaso S. pH-Controlled Liposomes for Enhanced Cell Penetration in Tumor Environment. ACS Appl Mater Interfaces 2018; 10:17646-17661. [PMID: 29737834 DOI: 10.1021/acsami.8b03469] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
An innovative pH-switchable colloidal system that can be exploited for site-selective anticancer drug delivery has been generated by liposome decoration with a new novel synthetic non-peptidic oligo-arginine cell-penetration enhancer (CPE) and a quenching PEGylated counterpart that detaches from the vesicle surface under the acidic conditions of tumors. The CPE module ( Arg4- DAG) is formed by four arginine units conjugated to a first-generation (G1) 2,2-bis(hydroxymethyl)propionic acid (bis-MPA)/2,2-bis(aminomethyl)propionic acid (bis-AMPA) polyester dendron terminating with 1,2-distearoyl-3-azidopropane for liposome bilayer insertion. The zeta potential of the Arg4- DAG-decorated liposomes increased up to +32 mV as the Arg4- DAG/lipids molar ratio increased. The Arg4- DAG liposome shielding at pH 7.4 was provided by methoxy-PEG5 kDa-polymethacryloyl sulfadimethoxine (mPEG5 kDa-SDM8) with 7.1 apparent p Ka. Zeta potential, surface plasmon resonance and synchrotron small-angle X-ray scattering analyses showed that at pH 7.4 mPEG5 kDa-SDM8 associates with polycationic Arg4- DAG-decorated liposomes yielding liposomes with neutral zeta potential. At pH 6.5, which mimics the tumor environment, mPEG5 kDa-SDM8 detaches from the liposome surface yielding Arg4- DAG exposure. Flow cytometry and confocal microscopy showed a 30-fold higher HeLa cancer cell association of the Arg4- DAG-decorated liposomes compared to non-decorated liposomes. At pH 7.4, the mPEG5 kDa-SDM8-coated liposomes undergo low cell association while remarkable cell association occurred at pH 6.5, which allowed for the controlled intracellular delivery of model macromolecules and small molecules loaded in the liposome under tumor conditions.
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Affiliation(s)
- Michela Barattin
- Department of Pharmaceutical and Pharmacological Sciences , University of Padova , Via F. Marzolo 5 , Padova 35131 , Italy
| | - Andrea Mattarei
- Department of Chemical Sciences , University of Padova , Via F. Marzolo 1 , Padova 35131 , Italy
| | - Anna Balasso
- Department of Pharmaceutical and Pharmacological Sciences , University of Padova , Via F. Marzolo 5 , Padova 35131 , Italy
| | - Cristina Paradisi
- Department of Chemical Sciences , University of Padova , Via F. Marzolo 1 , Padova 35131 , Italy
| | - Laura Cantù
- Department of Medical Biotechnologies and Traslational Medicine , University of Milano , LITA, Via F.lli Cervi, 93 , Segrate 20090 , Italy
| | - Elena Del Favero
- Department of Medical Biotechnologies and Traslational Medicine , University of Milano , LITA, Via F.lli Cervi, 93 , Segrate 20090 , Italy
| | - Tapani Viitala
- Centre for Drug Research and Division of Pharmaceutical Biosciences, Faculty of Pharmacy , University of Helsinki , Viikinkaari 5 , Helsinki FI-00014 , Finland
| | - Francesca Mastrotto
- Department of Pharmaceutical and Pharmacological Sciences , University of Padova , Via F. Marzolo 5 , Padova 35131 , Italy
| | - Paolo Caliceti
- Department of Pharmaceutical and Pharmacological Sciences , University of Padova , Via F. Marzolo 5 , Padova 35131 , Italy
| | - Stefano Salmaso
- Department of Pharmaceutical and Pharmacological Sciences , University of Padova , Via F. Marzolo 5 , Padova 35131 , Italy
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Naziris N, Pippa N, Meristoudi A, Pispas S, Demetzos C. Design and development of pH-responsive HSPC:C 12H 25-PAA chimeric liposomes. J Liposome Res 2017; 27:108-117. [PMID: 27558454 DOI: 10.3109/08982104.2016.1166512] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/13/2016] [Indexed: 01/07/2023]
Abstract
The application of stimuli-responsive medical practices has emerged, in which pH-sensitive liposomes figure prominently. This study investigates the impact of the incorporation of different amounts of pH-sensitive polymer, C12H25-PAA (poly(acrylic acid) with a hydrophobic end group) in l-α-phosphatidylcholine, hydrogenated (Soy) (HSPC) phospholipidic bilayers, with respect to biomimicry and functionality. PAA is a poly(carboxylic acid) molecule, classified as a pH-sensitive polymer, whose pH-sensitivity is attributed to its regulative -COOH groups, which are protonated under acidic pH (pKa ∼4.2). Our concern was to fully characterize, in a biophysical and thermodynamical manner, the mixed nanoassemblies arising from the combination of the two biomaterials. At first, we quantified the physicochemical characteristics and physical stability of the prepared chimeric nanosystems. Then, we studied their thermotropic behavior, through measurement of thermodynamical parameters, using Differential Scanning Calorimetry (DSC). Finally, the loading and release of indomethacin (IND) were evaluated, as well as the physicochemical properties and stability of the nanocarriers incorporating it. As expected, thermodynamical findings are in line with physicochemical results and also explain the loading and release profiles of IND. The novelty of this investigation is the utilization of these pH-sensitive chimeric advanced Drug Delivery nano Systems (aDDnSs) in targeted drug delivery which relies entirely on the biophysics and thermodynamics between such designs and the physiological membranes and environment of living organisms.
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Affiliation(s)
- Nikolaos Naziris
- a Department of Pharmaceutical Technology, Faculty of Pharmacy , National and Kapodistrian University of Athens , Athens , Greece and
| | - Natassa Pippa
- a Department of Pharmaceutical Technology, Faculty of Pharmacy , National and Kapodistrian University of Athens , Athens , Greece and
- b Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation , Athens , Greece
| | - Anastasia Meristoudi
- b Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation , Athens , Greece
| | - Stergios Pispas
- b Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation , Athens , Greece
| | - Costas Demetzos
- a Department of Pharmaceutical Technology, Faculty of Pharmacy , National and Kapodistrian University of Athens , Athens , Greece and
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Vila-Caballer M, Codolo G, Munari F, Malfanti A, Fassan M, Rugge M, Balasso A, de Bernard M, Salmaso S. A pH-sensitive stearoyl-PEG-poly(methacryloyl sulfadimethoxine)-decorated liposome system for protein delivery: An application for bladder cancer treatment. J Control Release 2016; 238:31-42. [PMID: 27444816 DOI: 10.1016/j.jconrel.2016.07.024] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 07/05/2016] [Accepted: 07/15/2016] [Indexed: 01/19/2023]
Abstract
Stealth pH-responsive liposomes for the delivery of therapeutic proteins to the bladder epithelium were prepared using methoxy-poly(ethylene glycol)5kDa-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (mPEG5kDa-DSPE) and stearoyl-poly(ethylene glycol)-poly(methacryloyl sulfadimethoxine) copolymer (stearoyl-PEG-polySDM), which possesses an apparent pKa of 7.2. Liposomes of 0.2:0.6:100, 0.5:1.5:100 and 1:3:100 mPEG5kDa-DSPE/stearoyl-PEG-polySDM/(soybean phosphatidylcholine+cholesterol) molar ratios were loaded with bovine serum albumin (BSA) as a protein model. The loading capacity was 1.3% w/w BSA/lipid. At pH7.4, all liposome formulations displayed a negative zeta-potential and were stable for several days. By pH decrease or addition to mouse urine, the zeta potential strongly decreased, and the liposomes underwent a rapid size increase and aggregation. Photon correlation spectroscopy (PCS) and transmission electron microscopy (TEM) analyses showed that the extent of the aggregation depended on the stearoyl-PEG-polySDM/lipid molar ratio. Cytofluorimetric analysis and confocal microscopy showed that at pH6.5, the incubation of MB49 mouse bladder cancer cells and macrophages with fluorescein isothiocyanate-labelled-BSA (FITC-BSA) loaded and N-(Lissamine Rhodamine B sulfonyl)-1, 2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine triethylammonium salt (rhodamine-DHPE) labelled 1:3:100 mPEG5kDa-DSPE/stearoyl-PEG-polySDM/lipid molar ratio liposomes resulted in a time-dependent liposome association with the cells. At pH7.4, the association of BSA-loaded liposomes with the MB49 cells and macrophages was remarkably lower than at pH6.5. Confocal images of bladder sections revealed that 2h after the instillation, liposomes at pH7.4 and control non-responsive liposomes at pH7.4 or 6.5 did not associate nor delivered FITC-BSA to the bladder epithelium. On the contrary, the pH-responsive liposome formulation set at pH6.5 and soon administered to mice by bladder instillation showed that, 2h after administration, the pH-responsive liposomes efficiently delivered the loaded FITC-BSA to the bladder epithelium.
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Bersani S, Vila-Caballer M, Brazzale C, Barattin M, Salmaso S. pH-sensitive stearoyl-PEG-poly(methacryloyl sulfadimethoxine) decorated liposomes for the delivery of gemcitabine to cancer cells. Eur J Pharm Biopharm 2014; 88:670-82. [PMID: 25157908 DOI: 10.1016/j.ejpb.2014.08.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 08/07/2014] [Accepted: 08/11/2014] [Indexed: 12/12/2022]
Abstract
Novel, acid-sensitive liposomes that respond to physiopathological pH for tumour targeting applications were obtained by surface decoration with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)] (mPEG-DSPE) and stearoyl-poly(ethylene glycol)-poly(methacryloyl sulfadimethoxine) copolymer (stearoyl-PEG-polySDM). The pH-sensitive stearoyl-PEG-polySDM copolymer contained an average of seven methacryloyl sulfadimethoxines per molecule and was found to possess an apparent pKa of 7.2. Preliminary cloud point studies showed that the hydrophilic/hydrophobic copolymer conversion occurred at pH 7.0. The copolymer was soluble above pH 7.0 and underwent aggregation at lower pH. Liposome formulations were prepared with 0.2:0.6:100, 0.5:1.5:100 and 1:3:100 mPEG-DSPE/stearoyl-PEG-polySDM/lipids molar ratios. All of the liposome formulations were stable at pH 7.4, even in the presence of foetal bovine serum, but they underwent rapid size increase at pH 6.5. TEM analysis showed that, at pH 6.5, the formulations coated with a stearoyl-PEG-polySDM/lipids molar ratio greater than 1:100 underwent aggregation. At pH 7.4, the liposomes showed negative zeta potential that significantly decreased after incubation at pH 6.5. Cell-culture studies indicated that the liposomes were not toxic up to 10mg/mL. Fluorescence spectroscopy, cytofluorimetry and confocal microscopy showed that at pH 6.5, the incubation of MCF-7 tumour cells with fluorescein-labelled 1:3:100 mPEG-DSPE/stearoyl-PEG-polySDM/lipids molar ratio liposomes resulted in time-dependent cell association, while at pH 7.4 the cell interaction was significantly lower. The same pH-responsive liposome formulation loaded with gemcitabine (98.2±4.7nmol gemcitabine/lipid μmol loading capacity) was stable at pH 7.4 for several hours, while at pH 6.5 it rapidly aggregated. At pH 6.5, these liposomes displayed higher cytotoxicity than at pH 7.4 or compared to non-responsive control liposomes at both incubation pH. Notably, treatment with free gemcitabine did not yield cytotoxic effects, indicating that the carrier can efficiently deliver the anticancer drug to the cytosolic compartment.
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Affiliation(s)
- Sara Bersani
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | | | - Chiara Brazzale
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Michela Barattin
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy
| | - Stefano Salmaso
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, Padova, Italy.
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