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Saini G, Trenchevska O, Howell LJ, Boyd JG, Smith DP, Jain V, Linford MR. Performance Comparison of Three Chemical Vapor Deposited Aminosilanes in Peptide Synthesis: Effects of Silane on Peptide Stability and Purity. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:11925-11932. [PMID: 30208711 DOI: 10.1021/acs.langmuir.8b01298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Silicon oxide substrates underwent gas-phase functionalization with various aminosilanes, and the resulting surfaces were evaluated for their suitability as a solid support for solid phase peptide synthesis (SPPS). APTES (3-aminopropyltriethoxysilane), APDEMS (3-aminopropyldiethoxymethylsilane), and APDIPES (3-aminopropyldiisopropylethoxysilane) were individually applied to thermal oxide-terminated silicon substrates via gas-phase deposition. Coated surfaces were characterized by spectroscopic ellipsometry (SE), contact angle goniometry, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and spectrophotometry. Model oligopeptides with 16 residues were synthesized on the amino surfaces, and the chemical stabilities of the resulting surfaces were evaluated against a stringent side chain deprotection (SCD) step, which contained trifluoroacetic acid (TFA) and trifluoromethanesulfonic acid (TFMSA). Functionalized surface thickness loss during SCD was most acute for APDIPES and the observed relative stability order was APTES > APDEMS > APDIPES. Amino surfaces were evaluated for compatibility with stepwise peptide synthesis where complete deprotection and coupling cycles are paramount. Model trimer syntheses indicated that routine capping of unreacted amines with acetic anhydride significantly increased purity as measured by MALDI-MS. An inverse correlation between the amine loading density and peptide purity was observed. In general, peptide purity was highest for the lowest amine density APDIPES surface.
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Affiliation(s)
- Gaurav Saini
- HealthTell Inc. , Chandler , Arizona 85226 , United States
| | | | - Loren J Howell
- HealthTell Inc. , Chandler , Arizona 85226 , United States
| | - James G Boyd
- HealthTell Inc. , Chandler , Arizona 85226 , United States
| | - David P Smith
- HealthTell Inc. , Chandler , Arizona 85226 , United States
| | - Varun Jain
- Department of Chemistry and Biochemistry , Brigham Young University , Provo , Utah 84602 , United States
| | - Matthew R Linford
- Department of Chemistry and Biochemistry , Brigham Young University , Provo , Utah 84602 , United States
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2
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Xin Q, Liu Q, Shah H, Gong JR. Electron spin resonance and fluorescence imaging assisted electrochemical approach for accurate and comprehensive monitoring of cellular hydrogen peroxide dynamics. Analyst 2017; 142:316-325. [DOI: 10.1039/c6an02006b] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new analytical system combining electrochemistry, ESR, and fluorescence imaging for accurately and comprehensively measuring the dynamics of cellular H2O2.
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Affiliation(s)
- Qi Xin
- CAS Center for Excellence in Nanoscience
- CAS Key Laboratory for Nanosystem and Hierarchical Fabrication
- National Center for Nanoscience and Technology
- Beijing 100190
- P. R. China
| | - Qian Liu
- CAS Center for Excellence in Nanoscience
- CAS Key Laboratory for Nanosystem and Hierarchical Fabrication
- National Center for Nanoscience and Technology
- Beijing 100190
- P. R. China
| | - Hameed Shah
- CAS Center for Excellence in Nanoscience
- CAS Key Laboratory for Nanosystem and Hierarchical Fabrication
- National Center for Nanoscience and Technology
- Beijing 100190
- P. R. China
| | - Jian Ru Gong
- CAS Center for Excellence in Nanoscience
- CAS Key Laboratory for Nanosystem and Hierarchical Fabrication
- National Center for Nanoscience and Technology
- Beijing 100190
- P. R. China
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Beavers KR, Mares JW, Swartz CM, Zhao Y, Weiss SM, Duvall CL. In situ synthesis of peptide nucleic acids in porous silicon for drug delivery and biosensing. Bioconjug Chem 2014; 25:1192-7. [PMID: 24949894 PMCID: PMC4103755 DOI: 10.1021/bc5001092] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
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Peptide nucleic acids (PNA) are a
unique class of synthetic molecules
that have a peptide backbone and can hybridize with nucleic acids.
Here, a versatile method has been developed for the automated, in
situ synthesis of PNA from a porous silicon (PSi) substrate for applications
in gene therapy and biosensing. Nondestructive optical measurements
were performed to monitor single base additions of PNA initiated from
(3-aminopropyl)triethoxysilane attached to the surface of PSi films,
and mass spectrometry was conducted to verify synthesis of the desired
sequence. Comparison of in situ synthesis to postsynthesis surface
conjugation of the full PNA molecules showed that surface mediated,
in situ PNA synthesis increased loading 8-fold. For therapeutic proof-of-concept,
controlled PNA release from PSi films was characterized in phosphate
buffered saline, and PSi nanoparticles fabricated from PSi films containing
in situ grown PNA complementary to micro-RNA (miR) 122 generated significant
anti-miR activity in a Huh7 psiCHECK-miR122 cell line. The applicability
of this platform for biosensing was also demonstrated using optical
measurements that indicated selective hybridization of complementary
DNA target molecules to PNA synthesized in situ on PSi films. These
collective data confirm that we have established a novel PNA–PSi
platform with broad utility in drug delivery and biosensing.
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Affiliation(s)
- Kelsey R Beavers
- Interdisciplinary Graduate Program in Materials Science, ‡Department of Electrical Engineering and Computer Science, and ∥Department of Biomedical Engineering, Vanderbilt University , Nashville, Tennessee 37235, United States
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Macias G, Hernández-Eguía LP, Ferré-Borrull J, Pallares J, Marsal LF. Gold-coated ordered nanoporous anodic alumina bilayers for future label-free interferometric biosensors. ACS APPLIED MATERIALS & INTERFACES 2013; 5:8093-8. [PMID: 23910449 DOI: 10.1021/am4020814] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A cost-effective label-free optical biosensor based on gold-coated self-ordered nanoporous anodic alumina bilayers is presented. The structure is formed by two uniform nanoporous layers of different porosity (i.e., a top layer with large pores and a bottom layer with smaller pores). Each layer presents uniform pore size, regular pore distribution, and regular diameter along its pore length. To increase and improve the output sensing signals, a thin gold layer on the top surface was deposited. The gold layer increases the refractive index contrast between the nanoporous alumina layer and the analytical aqueous solution, and it results in a greater contrast in the interferometric spectrum and a higher sensitivity of the structure. From this structurally engineered architecture, the resulting reflectivity spectrum shows a complex series of Fabry-Pérot interference fringes, which was analyzed by the reflective interferometric Fourier transform spectroscopy (RIFTS) method. To determine the performance of this structure for biosensing applications, we tested bovine serum albumin (BSA) as the target protein. The results show a significant enhancement of the RIFTS peak intensity and position when a gold layer is on the top surface.
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Affiliation(s)
- Gerard Macias
- Departament d'Enginyeria Electrònica, Elèctrica i Automàtica, ETSE, Universitat Rovira i Virgili, Avda. Països Catalans 26, 43007 Tarragona, Spain
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Martinez JO, Chiappini C, Ziemys A, Faust AM, Kojic M, Liu X, Ferrari M, Tasciotti E. Engineering multi-stage nanovectors for controlled degradation and tunable release kinetics. Biomaterials 2013; 34:8469-77. [PMID: 23911070 DOI: 10.1016/j.biomaterials.2013.07.049] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 07/15/2013] [Indexed: 11/24/2022]
Abstract
Nanovectors hold substantial promise in abating the off-target effects of therapeutics by providing a means to selectively accumulate payloads at the target lesion, resulting in an increase in the therapeutic index. A sophisticated understanding of the factors that govern the degradation and release dynamics of these nanovectors is imperative to achieve these ambitious goals. In this work, we elucidate the relationship that exists between variations in pore size and the impact on the degradation, loading, and release of multistage nanovectors. Larger pored vectors displayed faster degradation and higher loading of nanoparticles, while exhibiting the slowest release rate. The degradation of these particles was characterized to occur in a multi-step progression where they initially decreased in size leaving the porous core isolated, while the pores gradually increased in size. Empirical loading and release studies of nanoparticles along with diffusion modeling revealed that this prolonged release was modulated by the penetration within the porous core of the vectors regulated by their pore size.
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Affiliation(s)
- Jonathan O Martinez
- Department of Nanomedicine, The Methodist Hospital Research Institute, 6670 Bertner Ave., Houston, TX 77030, USA
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Cho C, Jeon JW, Lutkenhaus J, Zacharia NS. Electric field induced morphological transitions in polyelectrolyte multilayers. ACS APPLIED MATERIALS & INTERFACES 2013; 5:4930-4936. [PMID: 23683121 DOI: 10.1021/am400667y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
In this work, the morphological transitions in weak polyelectrolyte (PE) multilayers (PEMs) assembled from linear poly(ethylene imine) (LPEI) and poly(acrylic acid) (PAA) upon application of an electric field were studied. Exposure to an electric field results in the creation of a porous structure, which can be ascribed to local changes in pH from the hydrolysis of water and subsequent structural rearrangements of the weak PE constituents. Depending on the duration of application of the field, the porous transition gradually develops into a range of structures and pore sizes. It was discovered that the morphological transition of the LbL films starts at the multilayer-electrode interface and propagates through the film. First an asymmetrical structure forms, consisting of microscaled pores near the electrode and nanoscaled pores near the surface in contact with the electrolyte solution. At longer application of the field the porous structures become microscaled throughout. The results revealed in this study not only demonstrate experimental feasibility for controlling variation in pore size and porosity of multilayer films but also deepens the understanding of the mechanism of the porous transition. In addition, electrical potential is used to release small molecules from the PEMs.
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Affiliation(s)
- Chungyeon Cho
- Materials Science and Engineering Program, Texas A&M University, College Station, Texas 77843, United States
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Siyad MA, Kumar GSV. Synthetic evaluation of disulphide-bonded sarafotoxin on a poly(oxy ether) grafted dendrimeric poly(alkyl amine) support for polymer assisted organic synthesis. Org Biomol Chem 2013; 11:4860-70. [DOI: 10.1039/c3ob40178b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Wang F, Hui H, Barnes TJ, Barnett C, Prestidge CA. Oxidized Mesoporous Silicon Microparticles for Improved Oral Delivery of Poorly Soluble Drugs. Mol Pharm 2009; 7:227-36. [DOI: 10.1021/mp900221e] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Feng Wang
- Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA, 5095, Australia, Sansom Institute, University of South Australia, Adelaide, SA 5000, Australia, and pSiMedica Ltd, Malvern Hills Science Park, Geraldine Road, Malvern, WR14 3SZ, U.K
| | - He Hui
- Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA, 5095, Australia, Sansom Institute, University of South Australia, Adelaide, SA 5000, Australia, and pSiMedica Ltd, Malvern Hills Science Park, Geraldine Road, Malvern, WR14 3SZ, U.K
| | - Timothy J. Barnes
- Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA, 5095, Australia, Sansom Institute, University of South Australia, Adelaide, SA 5000, Australia, and pSiMedica Ltd, Malvern Hills Science Park, Geraldine Road, Malvern, WR14 3SZ, U.K
| | - Christian Barnett
- Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA, 5095, Australia, Sansom Institute, University of South Australia, Adelaide, SA 5000, Australia, and pSiMedica Ltd, Malvern Hills Science Park, Geraldine Road, Malvern, WR14 3SZ, U.K
| | - Clive A. Prestidge
- Ian Wark Research Institute, University of South Australia, Mawson Lakes, SA, 5095, Australia, Sansom Institute, University of South Australia, Adelaide, SA 5000, Australia, and pSiMedica Ltd, Malvern Hills Science Park, Geraldine Road, Malvern, WR14 3SZ, U.K
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Abstract
Silicon and its oxides are widely used in biomaterials research, tissue engineering and drug delivery. These materials are highly biocompatible, easily surface functionalized, degrade into nontoxic silicic acid and can be processed into various forms such as micro- and nano-particles, monoliths, membranes and micromachined structures. The large surface area of porous forms of silicon and silica (up to 1200 m2/g) permits high drug loadings. The degradation kinetics of silicon- and silica-based materials can be tailored by coating or grafting with polymers. Incorporation of polymers also improves control over drug-release kinetics. The use of stimuli-responsive polymers has enabled environmental stimuli-triggered drug release. Simultaneously, silicon microfabrication techniques have facilitated the development of sophisticated implantable drug-delivery microdevices. This paper reviews the synthesis, novel properties and biomedical applications of silicon–polymer hybrid materials with particular emphasis on drug delivery. The biocompatible and bioresorptive properties of mesoporous silica and porous silicon make these materials attractive candidates for use in biomedical applications. The combination of polymers with silicon-based materials has generated a large range of novel hybrid materials tailored to applications in localized and systemic drug delivery.
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Mosse WKJ, Koppens ML, Gengenbach TR, Scanlon DB, Gras SL, Ducker WA. Peptides grafted from solids for the control of interfacial properties. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:1488-1494. [PMID: 19118472 DOI: 10.1021/la802864v] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We have used solid-phase peptide synthesis to graft a peptide monolayer from a solid in order to modify the interfacial properties. We grafted a 15-residue peptide, EKEKEKEKEKEKEGG, containing a zwitterionic sequence of alternating lysine and glutamic acid residues from the surface of an aminosilanized silicon wafer by placing the silicon wafer within a commercial microwave peptide synthesizer. Such synthesizers are routinely used to make peptides on porous beads, but the peptides are subsequently cleaved and used independently of the solid support; our aim is to utilize the covalently bound peptide to control the surface properties without the need for cleavage and reattachment. We confirmed the presence of this peptide layer on the surface by X-ray photoelectron spectroscopy and ellipsometry. Atomic force microscopy was then used to study the forces between the peptide-modified surface and a borosilicate glass sphere as a function of the solution pH. The adsorbed peptide makes the silicon wafer pH responsive: at high pH the glass particle is repelled from the wafer, and at low pH it is attracted. Previous studies with synthetic polymers have shown that the "grafting from" method allows a much higher film density than "grafting to". We propose that the application of grafting from strategies to peptide layers may offer three additional benefits: (1) the film density can be controlled independently of the primary sequence of the peptide, (2) the sequence constraints for spontaneous adsorption are removed, and (3) the procedure is fast and efficient, which may lead to lower costs and the ability for high-throughput surface biofunctionalization. Moreover, peptide layers offer increased sequence diversity, control, and functionality compared to conventional polymer brushes.
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Affiliation(s)
- Wade K J Mosse
- The Department of Chemical and Biomolecular Engineering and The Bio21 Molecular Health and Biotechnology Institute, The University of Melbourne, Victoria 3010, Australia
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