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Wiwatchaitawee K, Ebeid K, Quarterman JC, Naguib Y, Ali MY, Oliva C, Griguer C, Salem AK. Surface Modification of Nanoparticles Enhances Drug Delivery to the Brain and Improves Survival in a Glioblastoma Multiforme Murine Model. Bioconjug Chem 2022; 33:1957-1972. [PMID: 35041398 DOI: 10.1021/acs.bioconjchem.1c00479] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Glioblastoma multiforme (GBM) is the most malignant type of brain tumor and has an extremely poor prognosis. Current treatment protocols lack favorable outcomes, and alternative treatments with superior efficacy are needed. In this study, we demonstrate that loading paclitaxel (PTX) in a polymeric, nanoparticulate delivery system is capable of improving its brain accumulation and therapeutic activity. We independently incorporated two different positively charged surface modifiers, poly(amidoamine) (PAMAM) and poly(ethylenimine) (PEI), onto poly(lactic-co-glycolic acid) (PLGA)-polyethylene glycol (PEG), PLGA-PEG, nanoparticles (NPs) using a modified nanoprecipitation technique that assures the formation of nanosized particles while exposing the positively charged polymer on the surface. The prepared NPs underwent comprehensive analyses of their size, charge, in vitro permeability against a BBB cell line, and in vivo biodistribution. Our results demonstrated the successful fabrication of positively charged NPs using PAMAM or PEI. Importantly, significant improvement in brain accumulation (in vivo) was associated with NPs containing PAMAM compared to unmodified NPs or NPs containing PEI. Finally, the efficacy of PAMAM-modified NPs loaded with PTX was evaluated with orthotopic human GBM xenografts in a mouse model, and the data demonstrated improved survival and equivalent safety compared to soluble PTX. Our data substantiate the importance of surface chemistry on the magnitude of NP accumulation in the brain and pave the way for further in vivo evaluation of chemotherapeutic drugs against GBM that have previously been overlooked because of their limited ability to cross the BBB.
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Affiliation(s)
- Kanawat Wiwatchaitawee
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, Iowa 52242, United States
| | - Kareem Ebeid
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, Iowa 52242, United States.,Department of Pharmaceutics, Faculty of Pharmacy, Minia University, Minia, Minia 61519, Egypt.,Department of Pharmaceutics, Faculty of Pharmacy and Pharmaceutical Manufacturing, Deraya University, New Minia City, Minia 61768, Egypt
| | - Juliana C Quarterman
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, Iowa 52242, United States
| | - Youssef Naguib
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, Iowa 52242, United States.,Department of Pharmaceutics, Faculty of Pharmacy, Minia University, Minia, Minia 61519, Egypt.,Department of Pharmaceutics, Faculty of Pharmacy and Pharmaceutical Manufacturing, Deraya University, New Minia City, Minia 61768, Egypt
| | - Md Yousuf Ali
- Interdisciplinary Graduate Program in Human Toxicology, University of Iowa, Iowa City, Iowa 52242, United States.,Free Radical & Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa 52242, United States.,Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, United States
| | - Claudia Oliva
- Free Radical & Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa 52242, United States.,Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, United States
| | - Corinne Griguer
- Free Radical & Radiation Biology Program, Department of Radiation Oncology, Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa 52242, United States.,Department of Radiation Oncology, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242, United States
| | - Aliasger K Salem
- Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, Iowa 52242, United States.,Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa 52242, United States
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2
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Tuning Drug Release via Twin Screw Extrusion in Polyester Films. J Pharm Sci 2019; 108:2430-2437. [DOI: 10.1016/j.xphs.2019.02.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 02/24/2019] [Accepted: 02/27/2019] [Indexed: 11/17/2022]
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3
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Harting R, Johnston K, Petersen S. Correlating in vitro degradation and drug release kinetics of biopolymer-based drug delivery systems. INTERNATIONAL JOURNAL OF BIOBASED PLASTICS 2019. [DOI: 10.1080/24759651.2018.1563358] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- R. Harting
- Laboratory for Chemistry and Surface Modification, University of Applied Sciences Osnabrück, Osnabrück, Germany
| | - K. Johnston
- Department Engineering, University of Wisconsin-Madison, Madison, WI, USA
| | - S. Petersen
- Laboratory for Chemistry and Surface Modification, University of Applied Sciences Osnabrück, Osnabrück, Germany
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4
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Novel approach for a PTX/VEGF dual drug delivery system in cardiovascular applications—an innovative bulk and surface drug immobilization. Drug Deliv Transl Res 2018. [DOI: 10.1007/s13346-018-0507-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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5
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Bagheri M, Mohammadi M, Steele TW, Ramezani M. Nanomaterial coatings applied on stent surfaces. Nanomedicine (Lond) 2017; 11:1309-26. [PMID: 27111467 DOI: 10.2217/nnm-2015-0007] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The advent of percutaneous coronary intervention and intravascular stents has revolutionized the field of interventional cardiology. Nonetheless, in-stent restenosis, inflammation and late-stent thrombosis are the major obstacles with currently available stents. In order to enhance the hemocompatibility of stents, advances in the field of nanotechnology allow novel designs of nanoparticles and biomaterials toward localized drug/gene carriers or stent scaffolds. The current review focuses on promising polymers used in the fabrication of newer generations of stents with a short synopsis on atherosclerosis and current commercialized stents, nanotechnology's impact on stent development and recent advancements in stent biomaterials is discussed in context.
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Affiliation(s)
- Mahsa Bagheri
- Shariati Hospital, Mashhad University of Medical Sciences, Mashhad, PO Box 935189-9983, Iran.,Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, PO Box 91775-1365, Iran
| | - Marzieh Mohammadi
- Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, PO Box 91775-1365, Iran
| | - Terry Wj Steele
- Division of Materials Technology, Materials & Science Engineering, Nanyang Technological University, Singapore
| | - Mohammad Ramezani
- Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, PO Box 91775-1365, Iran
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6
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Novel Poly(Diol Sebacate)s as Additives to Modify Paclitaxel Release From Poly(Lactic-co-Glycolic Acid) Thin Films. J Pharm Sci 2017; 106:2106-2114. [PMID: 28535975 DOI: 10.1016/j.xphs.2017.05.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 05/15/2017] [Accepted: 05/16/2017] [Indexed: 01/23/2023]
Abstract
Paclitaxel (PTX) incorporation in poly(lactic-co-glycolic acid) (PLGA) matrices produce films with high tensile rigidity and slow release that fail to deliver the required release rate for most biomedical applications such as in drug eluting stents and cancer treatments. To modify and improve this behavior, a set of poly(diol sebacate)s were synthesized and fully characterized as possible additives. The tensile properties of PLGA blends were evaluated as these materials could be used as coatings in drug eluting stent applications. A significant improvement in mechanical flexibility was observed with 20% additive content, as it reduced the Young's modulus value and increased the maximum deformation at break. PTX release was studied and correlated with the release of additive from PLGA films. An increase in the initial burst release phase was observed on all blends when compared to the control films of PLGA. Modulation of PTX release was achieved by altering the hydrophilicity degree of the additive or its percentage content on the blend. This supports the possibility that PTX was partitioned into the additive phase. Cytotoxicity analyses of novel additives were performed on mouse embryonic fibroblasts NIH/3T3.
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7
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Self-assembled photoadditives in polyester films allow stop and go chemical release. Acta Biomater 2017; 54:186-200. [PMID: 28315815 DOI: 10.1016/j.actbio.2017.03.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 03/04/2017] [Accepted: 03/13/2017] [Indexed: 12/16/2022]
Abstract
Near-infrared (NIR) triggered chemical delivery allows on-demand release with the advantage of external tissue stimulation. Bioresorbable polyester poly-l-lactic acid (PLLA) was compounded with photoadditives of neat zinc oxide (ZnO) nanoparticles and 980→365nm LiYF4:Tm3+, Yb3+ upconverting nanoparticles (UCNP). Subsequently, neat ZnO and UCNP blended PLLA films of sub-50μm thickness were knife casted with a hydrophobic small molecule drug mimic, fluorescein diacetate. The PLLA films displayed a 500 times increase in fluorescein diacetate release from the 50mW NIR irradiated PLLA/photoadditive film compared to non-irradiated PLLA control films. Larger ratios of UCNP/neat ZnO increased photocatalysis efficiency at low NIR duty cycles. The synergistic increase results from the self-assembled photoadditives of neat zinc oxide and upconverting nanoparticles (UCNPs), as seen in transmission electron microscopy. Colloidal ZnO, which does not self-assemble with UCNPs, had less than half the release kinetics of the self-assembled PLLA films under similar conditions, advocating Förster resonance energy transfer as the mechanism responsible for the synergistic increase. Alternative to intensity modulation, pulse width modulation (duty cycles from 0.1 to 1) of the low intensity 50mW NIR laser diode allowed tailorable release rates from 0.01 to 1.4% per day. With the low intensity NIR activation, tailorable release rates, and favorable biocompatibility of the constituents, implanted PLLA photoadditive thin films could allow feedback mediated chemical delivery. STATEMENT OF SIGNIFICANCE Upconverting nanoparticles and zinc oxide nanorods were found to spontaneously self-assemble into submicron particles in organic solvents. Exposure of the submicron particles to near-infrared light allows stop and go chemical release from biocompatible polymers. Sample preparation of thin films is done with ease through physical mixing of the photoadditives followed by air-dried knife casting. A colloidal ZnO variant that does not self-assemble with upconverting nanoparticles had slower chemical release, suggesting that synergistic chemical release is brought upon by highly efficient energy transfer mechanisms when the nanoparticles are less than 10nm apart. Never before seen composite particles of UCNP/ZnO are displayed, which shows the close interaction of the photoadditives within the polymer matrix.
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8
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Schaller T, Wenner T, Agrawal R, Teoh S, Phua LT, Loo JSC, Steele TWJ. High Throughput Screening of Valganciclovir in Acidic Microenvironments of Polyester Thin Films. MATERIALS 2015; 8:1714-1728. [PMID: 28788027 PMCID: PMC5507036 DOI: 10.3390/ma8041714] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Revised: 03/19/2015] [Accepted: 03/30/2015] [Indexed: 01/12/2023]
Abstract
Ganciclovir and valganciclor are antiviral agents used for the treatment of cytomegalovirus retinitis. The conventional method for administering ganciclovir in cytomegalovirus retinitis patients is repeated intravitreal injections. In order to obviate the possible detrimental effects of repeated intraocular injections, to improve compliance and to eliminate systemic side-effects, we investigated the tuning of the ganciclovir pro-drug valganciclovir and the release from thin films of poly(lactic-co-glycolic acid) (PLGA), polycaprolactone (PCL), or mixtures of both, as a step towards prototyping periocular valganciclovir implants. To investigate the drug release, we established and evaluated a high throughput fluorescence-based quantification screening assay for the detection of valganciclovir. Our protocol allows quantifying as little as 20 ng of valganciclovir in 96-well polypropylene plates and a 50× faster analysis compared to traditional HPLC measurements. This improvement can hence be extrapolated to other polyester matrix thin film formulations using a high-throughput approach. The acidic microenvironment within the polyester matrix was found to protect valganciclovir from degradation with resultant increases in the half-life of the drug in the periocular implant to 100 days. Linear release profiles were obtained using the pure polyester polymers for 10 days and 60 days formulations; however, gross phase separations of PCL and acid-terminated PLGA prevented tuning within these timeframes due to the phase separation of the polymer, valganciclovir, or both.
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Affiliation(s)
- Teilo Schaller
- School of Materials Science & Engineering, Nanyang Technological University, 50 Nanyang Drive, Singapore 639798, Singapore.
| | - Tobias Wenner
- School of Materials Science & Engineering, Nanyang Technological University, 50 Nanyang Drive, Singapore 639798, Singapore.
| | - Rupesh Agrawal
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore.
| | - Stephen Teoh
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore.
| | - Li Ting Phua
- School of Materials Science & Engineering, Nanyang Technological University, 50 Nanyang Drive, Singapore 639798, Singapore.
| | - Joachim S C Loo
- School of Materials Science & Engineering, Nanyang Technological University, 50 Nanyang Drive, Singapore 639798, Singapore.
| | - Terry W J Steele
- School of Materials Science & Engineering, Nanyang Technological University, 50 Nanyang Drive, Singapore 639798, Singapore.
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9
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Cheng T, Ortiz RF, Vedantham K, Naccache R, Vetrone F, Marks RS, Steele TW. Tunable Chemical Release from Polyester Thin Film by Photocatalytic Zinc Oxide and Doped LiYF4 Upconverting Nanoparticles. Biomacromolecules 2014; 16:364-73. [DOI: 10.1021/bm501567m] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Ting Cheng
- School of Materials Science & Engineering, College of Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Raphael Francois Ortiz
- School of Materials Science & Engineering, College of Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Kumar Vedantham
- School of Materials Science & Engineering, College of Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Rafik Naccache
- Institut
National de la Recherche Scientifique—Énergie, Matériaux,
et Télécommunications, Université du Québec, 1650
Lionel-Boulet, Varennes, Québec J3X 1S2, Canada
| | - Fiorenzo Vetrone
- Institut
National de la Recherche Scientifique—Énergie, Matériaux,
et Télécommunications, Université du Québec, 1650
Lionel-Boulet, Varennes, Québec J3X 1S2, Canada
| | - Robert S. Marks
- School of Materials Science & Engineering, College of Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
- Department
of Biotechnology Engineering, Faculty of Engineering Sciences, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105, Israel
| | - Terry W.J. Steele
- School of Materials Science & Engineering, College of Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
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10
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Pretor S, Bartels J, Lorenz T, Dahl K, Finke JH, Peterat G, Krull R, Al-Halhouli AT, Dietzel A, Büttgenbach S, Behrends S, Reichl S, Müller-Goymann CC. Cellular Uptake of Coumarin-6 under Microfluidic Conditions into HCE-T Cells from Nanoscale Formulations. Mol Pharm 2014; 12:34-45. [DOI: 10.1021/mp500401t] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- S. Pretor
- Institut für Pharmazeutische Technologie, Technische Universität Braunschweig, Mendelssohnstraße 1, 38106 Braunschweig, Germany
| | - J. Bartels
- Institut für Pharmakologie, Toxikologie und Klinische
Pharmazie, Technische Universität Braunschweig, Mendelssohnstraße
1, 38106 Braunschweig, Germany
| | - T. Lorenz
- Institut für Mikrotechnik, Technische Universität Braunschweig, Alte Salzdahlumer Straße 203, 38124 Braunschweig, Germany
| | - K. Dahl
- Institut für Pharmazeutische Technologie, Technische Universität Braunschweig, Mendelssohnstraße 1, 38106 Braunschweig, Germany
| | - J. H. Finke
- Institut für Pharmazeutische Technologie, Technische Universität Braunschweig, Mendelssohnstraße 1, 38106 Braunschweig, Germany
| | - G. Peterat
- Institute for Biochemical Engineering, Technische Universität Braunschweig, Gaußstraße 17, 38106 Braunschweig, Germany
| | - R. Krull
- Institute for Biochemical Engineering, Technische Universität Braunschweig, Gaußstraße 17, 38106 Braunschweig, Germany
| | - A. T. Al-Halhouli
- Institut für Mikrotechnik, Technische Universität Braunschweig, Alte Salzdahlumer Straße 203, 38124 Braunschweig, Germany
| | - A. Dietzel
- Institut für Mikrotechnik, Technische Universität Braunschweig, Alte Salzdahlumer Straße 203, 38124 Braunschweig, Germany
| | - S. Büttgenbach
- Institut für Mikrotechnik, Technische Universität Braunschweig, Alte Salzdahlumer Straße 203, 38124 Braunschweig, Germany
| | - S. Behrends
- Institut für Pharmakologie, Toxikologie und Klinische
Pharmazie, Technische Universität Braunschweig, Mendelssohnstraße
1, 38106 Braunschweig, Germany
| | - S. Reichl
- Institut für Pharmazeutische Technologie, Technische Universität Braunschweig, Mendelssohnstraße 1, 38106 Braunschweig, Germany
| | - C. C. Müller-Goymann
- Institut für Pharmazeutische Technologie, Technische Universität Braunschweig, Mendelssohnstraße 1, 38106 Braunschweig, Germany
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11
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Mogal VT, Yin CS, O'Rorke R, Boujday S, Méthivier C, Venkatraman SS, Steele TWJ. Tuning model drug release and soft-tissue bioadhesion of polyester films by plasma post-treatment. ACS APPLIED MATERIALS & INTERFACES 2014; 6:5749-5758. [PMID: 24666261 DOI: 10.1021/am500454b] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Plasma treatments are investigated as a post-production method of tuning drug release and bioadhesion of poly(lactic-co-glycolic acid) (PLGA) thin films. PLGA films were treated under varying conditions by controlling gas flow rate, composition, treatment time, and radio frequency (RF) power. In vitro release of the drug-like molecule fluorescein diacetate (FDAc) from plasma-treated PLGA was tunable by controlling RF power; an increase of 65% cumulative release is reported compared to controls. Bioadhesion was sensitive to RF power and treatment time, assessed using ex vivo shear-stress tests with wetted swine aorta. We report a maximum bioadhesion ∼6-fold that of controls and 5-fold that of DOPA-based mussel adhesives tested to swine skin.1 The novelty of this post-treatment is the activation of a hydrophobic polyester film for bioadhesion, which can be quenched, while simultaneously tuning drug-release kinetics. This exemplifies the promise of plasma post-treatment for in-clinic bioadhesive activation, along with technological advancements, i.e., atmospheric plasma and hand-held "plasma pencils".
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Affiliation(s)
- Vishal T Mogal
- Materials and Science Engineering, Division of Materials Technology, Nanyang Technological University , Singapore 639798, Republic of Singapore
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12
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Kathawala MH, Xiong S, Richards M, Ng KW, George S, Loo SCJ. Emerging in vitro models for safety screening of high-volume production nanomaterials under environmentally relevant exposure conditions. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2013; 9:1504-1520. [PMID: 23019115 DOI: 10.1002/smll.201201452] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Indexed: 06/01/2023]
Abstract
The rising production of nanomaterial-based consumer products has raised safety concerns. Testing these with animal and other direct models is neither ethically nor economically viable, nor quick enough. This review aims to discuss the strength of in vitro testing, including the use of 2D and 3D cultures, stem cells, and tissue constructs, etc., which would give fast and repeatable answers of a highly specific nature, while remaining relevant to in vivo outcomes. These results can then be combined and the overall toxicity predicted with relative accuracy. Such in vitro models can screen potentially toxic nanomaterials which, if required, can undergo further stringent studies in animals. The cyto- and phototoxicity of some high-volume production nanomaterials, using in vitro models, is also reviewed.
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Affiliation(s)
- Mustafa Hussain Kathawala
- Nanyang Technological University, School of Materials Science and Engineering, 50 Nanyang Avenue, Singapore 639798, Singapore
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13
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McManamon C, Delaney P, Kavanagh C, Wang JJ, Rasappa S, Morris MA. Depth profiling of PLGA copolymer in a novel biomedical bilayer using confocal Raman spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:5905-5910. [PMID: 23594126 DOI: 10.1021/la400402a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Confocal Raman spectroscopy was undertaken to identify separate layers of PLGA and gentamicin sulfate (GS) coatings on a titanium alloy substrate for a novel drug-delivery system. Additionally, it was found that it was possible to measure the layer thickness and uniformity of the PLGA accurately by detecting intensity and wavelength changes in the vibrational bands of the copolymer bonds. Further analysis of the materials was done using FIB, SEM/EDX, and profilometry; these techniques were used to confirm the findings of the Raman data. It was determined that the substrate was extremely rough and therefore the coating was not uniform in thickness but the materials were uniformly dispersed. Most importantly, two distinct GS and PLGA layers were present.
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Affiliation(s)
- Colm McManamon
- Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2, Ireland
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14
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Huang CL, Kumar S, Tan JJ, Boey FY, Venkatraman SS, Steele TW, Loo JS. Modulating drug release from poly(lactic-co-glycolic acid) thin films through terminal end-groups and molecular weight. Polym Degrad Stab 2013. [DOI: 10.1016/j.polymdegradstab.2012.11.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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15
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Steele TWJ, Huang CL, Kumar S, Irvine S, Boey FYC, Loo JSC, Venkatraman SS. Novel gradient casting method provides high-throughput assessment of blended polyester poly(lactic-co-glycolic acid) thin films for parameter optimization. Acta Biomater 2012; 8:2263-70. [PMID: 22293582 DOI: 10.1016/j.actbio.2012.01.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 12/07/2011] [Accepted: 01/10/2012] [Indexed: 11/16/2022]
Abstract
Pure polymer films cannot meet the diverse range of controlled release and material properties demanded for the fabrication of medical implants or other devices. Additives are added to modulate and optimize thin films for the desired qualities. To characterize the property trends that depend on additive concentration, an assay was designed which involved casting a single polyester poly(lactic-co-glycolic acid) (PLGA) film that blends a linear gradient of any PLGA-soluble additive desired. Four gradient PLGA films were produced by blending polyethylene glycol or the more hydrophobic polypropylene glycol. The films were made using a custom glass gradient maker in conjunction with a 180 cm film applicator. These films were characterized in terms of thickness, percent additive, total polymer (PLGA+additive), and controlled drug release using drug-like fluorescent molecules such as coumarin 6 (COU) or fluorescein diacetate (FDAc). Material properties of elongation and modulus were also accessed. Linear gradients of additives were readily generated, with phase separation being the limiting factor. Additive concentration had a Pearson's correlation factor (R) of >0.93 with respect to the per cent total release after 30 days for all gradients characterized. Release of COU had a near zero-order release over the same time period, suggesting that coumarin analogs may be suitable for use in PLGA/polyethylene glycol or PLGA/polypropylene glycol matrices, with each having unique material properties while allowing tuneable drug release. The gradient casting method described has considerable potential in offering higher throughput for optimizing film or coating material properties for medical implants or other devices.
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Affiliation(s)
- Terry W J Steele
- Nanyang Technological University, Materials and Science Engineering, Division of Materials Technology, Singapore 639798, Singapore
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16
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Ma C, Pang D, Xiong Z, Bai W, Xiong C. Cellular responses to electrospun membranes made from blends of PLLGA with PEG and PLLGA-b-PEG. J Biomed Mater Res A 2012; 100:2897-904. [PMID: 22696182 DOI: 10.1002/jbm.a.34226] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Revised: 04/02/2012] [Accepted: 04/23/2012] [Indexed: 01/13/2023]
Abstract
Control of cellular responses is crucial for the use of electrospun membranes in biomedical applications, including tissue engineering or biomedical devices. However, it is still unclear whether adhesion and proliferation of fibroblasts is stimulated or inhibited on polyethylene glycol (PEG)-modified electrospun membranes. In this study, poly(L-lactide-co-glycolide) (PLLGA)-PEG copolymer and pure PEG were blended with PLLGA, and then electrospun onto nonwoven membranes. The effects of blending of PLLGA-PEG or pure PEG on the adsorption of proteins, and further on the adhesion and proliferation of L929 fibroblasts on the electrospun membranes were investigated. Addition of PLLGA-PEG or PEG significantly improved the hydrophilicity of the electrospun membranes. Pure PEG had no obvious effects on the growth of L929 fibroblasts; in contrast, PLLGA-PEG significantly inhibited the adsorption of proteins and the proliferations of the cells on the electrospun membranes. In response to diminished protein adsorption, mRNA expression of genes related to cell adhesion and migration was up-regulated. The limited effects of pure PEG were probably caused by its preferential dissolution, whereas membrane-confined PLLGA-PEG displayed excellent performance on the inhibition of protein adsorption and cell proliferation.
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Affiliation(s)
- Chi Ma
- Polymer Department, Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu, China
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Weldon CB, Tsui JH, Shankarappa SA, Nguyen VT, Ma M, Anderson DG, Kohane DS. Electrospun drug-eluting sutures for local anesthesia. J Control Release 2012; 161:903-9. [PMID: 22609349 DOI: 10.1016/j.jconrel.2012.05.021] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2012] [Revised: 04/18/2012] [Accepted: 05/10/2012] [Indexed: 11/16/2022]
Abstract
We have developed a local anesthetic-eluting suture system which would combine the function and ubiquity of the suture for surgical repair with the controlled release properties of a biodegradable polymeric matrix. Drug-free and drug-loaded poly(lactic-co-glycolic acid) (PLGA) sutures were fabricated by electrospinning, with or without the local anesthetic bupivacaine. The tensile strength of the electrospun sutures decreased as drug content increased, but strains remained relatively similar across all groups. Sutures released their entire drug payload over the course of 12 days and maintained approximately 12% of their initial tensile strength after 14 days of incubation in vitro. In a rat skin wound model, local analgesia was achieved 1 day after surgery and lasted approximately 1 week in 90% of treated animals (n=10, p<0.05), and all wounds were able to heal normally without the need for further reinforcement. The sutures caused tissue reaction in vivo that was comparable to that seen with a commercially available suture composed of PLGA. Such sutures may enhance perioperative analgesia and mitigate the need for standard postoperative opioid analgesics.
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Affiliation(s)
- Christopher B Weldon
- Department of Surgery, Children's Hospital Boston, Harvard Medical School, 300 Longwood Ave., Boston, Massachusetts 02115, USA
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Abstract
RATIONALE β-Adrenergic receptor stimulation produces sarcoplasmic reticulum Ca(2+) overload and delayed afterdepolarizations in isolated ventricular myocytes. How delayed afterdepolarizations are synchronized to overcome the source-sink mismatch and produce focal arrhythmia in the intact heart remains unknown. OBJECTIVE To determine whether local β-adrenergic receptor stimulation produces spatiotemporal synchronization of delayed afterdepolarizations and to examine the effects of tissue geometry and cell-cell coupling on the induction of focal arrhythmia. METHODS AND RESULTS Simultaneous optical mapping of transmembrane potential and Ca(2+) transients was performed in normal rabbit hearts during subepicardial injections (50 μL) of norepinephrine (NE) or control (normal Tyrode's solution). Local NE produced premature ventricular complexes (PVCs) from the injection site that were dose-dependent (low-dose [30-60 μmol/L], 0.45±0.62 PVCs per injection; high-dose [125-250 μmol/L], 1.33±1.46 PVCs per injection; P<0.0001) and were inhibited by propranolol. NE-induced PVCs exhibited abnormal voltage-Ca(2+) delay at the initiation site and were inhibited by either sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase inhibition or reduced perfusate [Ca(2+)], which indicates a Ca(2+)-mediated mechanism. NE-induced PVCs were more common at right ventricular than at left ventricular sites (1.48±1.50 versus 0.55±0.89, P<0.01), and this was unchanged after chemical ablation of endocardial Purkinje fibers, which suggests that source-sink interactions may contribute to the greater propensity to right ventricular PVCs. Partial gap junction uncoupling with carbenoxolone (25 μmol/L) increased focal activity (2.18±1.43 versus 1.33±1.46 PVCs per injection, P<0.05), which further supports source-sink balance as a critical mediator of Ca(2+)-induced PVCs. CONCLUSIONS These data provide the first experimental demonstration that localized β-adrenergic receptor stimulation produces spatiotemporal synchronization of sarcoplasmic reticulum Ca(2+) overload and release in the intact heart and highlight the critical nature of source-sink balance in initiating focal arrhythmias.
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