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1.
Nanomedicine (Lond) ; 18(7): 589-597, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-37199174

RESUMO

Aims: The density of functional ligands on lipid nanoparticles (LNPs) greatly determined its capability of postfunctionalization and targetability for the applications of personalized nanomedicine and drug/gene delivery. This work is to investigate whether and how formulation methods influence the presentation of surface ligands. Methods: Biotin-modified LNPs as a functional LNP model were synthesized by four different formulation methods. The biotin ligand density and targetability of biotin-LNPs were evaluated and compared. Results: Both the ligand density and targetability of biotin-LNPs formulated by four different formulation methods exhibited a similar trend: homogenization > extrusion > wave-shaped micromixer ≈ Y-shaped micromixer. Conclusion: Formulation methods could modulate the presentation of targeting ligands on LNPs, which could guide future formulation screening and nanomedicine engineering.


Assuntos
Biotina , Nanopartículas , Ligantes , Sistemas de Liberação de Medicamentos , RNA Interferente Pequeno
2.
ACS Appl Mater Interfaces ; 14(14): 16538-16545, 2022 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-35357800

RESUMO

We report the fabrication of DNA-templated Pt nanostructures by area-selective atomic layer deposition. A DNA-templated self-assembled monolayer was used to mediate the area-selective deposition of Pt. Using this approach, we demonstrated the fabrication of both single- and two-component nanostructure patterns, including Pt, TiO2/Pt, and Al2O3/Pt. These nanoscale patterns were used as hard masks for plasma deep etching of Si to fabricate anti-reflection surfaces. This work demonstrated a gas-phase, DNA-templated fabrication of metal nanostructures, which complements earlier work of solution-based DNA metallization. The nanostructures obtained here are useful for applications in nanoelectronics, nanophotonics, and surface engineering.


Assuntos
Nanoestruturas , Nanotecnologia , DNA/química , Engenharia , Metais/química , Nanoestruturas/química
3.
ACS Biomater Sci Eng ; 7(1): 90-95, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33338373

RESUMO

This paper reports an antibacterial chip that can selectively capture bacteria and kill them using low-voltage DC electricity. We prepared a bacteria-imprinted, flexible PDMS chip that can separate target bacteria from suspensions with high selectivity. The chip contained integrated electrodes that can kill the captured bacteria within 10 min by applying a low DC voltage. The used chip could be easily regenerated by solution immersion. Meanwhile, the PDMS chip showed good biocompatibility and inhibited adhesion of human blood cells. Our work points to a new strategy to address pathogenic bacterial contamination and infection.


Assuntos
Antibacterianos , Bactérias , Humanos
4.
ACS Nano ; 14(10): 13047-13055, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33048526

RESUMO

We demonstrate area-selective atomic layer deposition (ALD) of oxides on DNA nanostructures. Area-selective ALD of Al2O3, TiO2, and HfO2 was successfully achieved on both 2D and 3D DNA nanostructures deposited on a polystyrene (PS) substrate. The resulting DNA-inorganic hybrid structure was used as a hard mask to achieve deep etching of a Si wafer for antireflection applications. ALD is a widely used process in coating and thin film deposition; our work points to a way to pattern oxide materials using DNA templates and to enhance the chemical/physical stability of DNA nanostructures for applications in surface engineering.


Assuntos
Nanoestruturas , DNA , Engenharia , Óxidos , Propriedades de Superfície
5.
Langmuir ; 35(38): 12543-12549, 2019 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-31433657

RESUMO

This paper reports antifouling properties of nanostructured SiO2 substrates patterned by DNA lithography. We used DNA triangle nanostructures as templates to produce triangular-shaped trenches ca. 130 nm in size on SiO2 surfaces. Using B. subtilis as a bacterial model, we found that such nanopatterned surface showed a 75% reduction in bacterial adhesion and 72% reduction in biofilm density at 35% surface coverage of the nanoscale triangular trenches. DNA-based nanofabrication can produce high-resolution designer patterns, but aligning these patterns has been one of the major technical challenges for its applications in nanoelectronics. This work demonstrates the potential of DNA-based nanofabrication in antifouling applications, where surface patterning of micro/nanostructures is required but not their precise alignment.


Assuntos
Incrustação Biológica/prevenção & controle , DNA/química , DNA/farmacologia , Nanoestruturas/química , Dióxido de Silício/química , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/fisiologia , Aderência Bacteriana/efeitos dos fármacos
6.
Small ; 15(26): e1805428, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30811832

RESUMO

This Concept provides an overview of recent developments of DNA-based nanofabrication and discusses its potential applications in the area of surface engineering. The first part of the paper discusses the strength and limitations of existing DNA-based nanofabrication methods. The second part highlights several examples of surface engineering applications involving nano- and microscale surface textures. It finishes with a discussion of the opportunities and remaining challenges of applying DNA-based nanofabrication in surface engineering applications.


Assuntos
DNA/química , Nanoestruturas/química , Nanotecnologia/métodos
7.
Sci Rep ; 6: 19028, 2016 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-26754463

RESUMO

It is found that carbon quantum dots (CQDs) self-assemble to a layer structure at ice crystals-water interface with freeze- drying. Such layers interconnect with each other, forming a free-standing CQD assembly, which has an interlayer distance of about 0.366 nm, due to the existence of curved carbon rings other than hexagons in the assembly. CQDs are fabricated by rupturing C60 by KOH activation with a production yield of ~15 wt.%. The CQDs obtained have an average height of 1.14 nm and an average lateral size of 7.48 nm, and are highly soluble in water. By packaging annealed CQD assembly to high density (1.23 g cm(-3)) electrodes in supercapacitors, a high volumetric capacitance of 157.4 F cm(-3) and a high areal capacitance of 0.66 F cm(-2) (normalized to the loading area of electrodes) are demonstrated in 6 M KOH aqueous electrolyte with a good rate capability.

8.
ACS Appl Mater Interfaces ; 8(1): 20-5, 2016 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-26696468

RESUMO

Whereas diverse graphene quantum dots (GQDs) with basal planes similar to those of graphene oxide sheets (i.e., GO-GQDs) lack antibacterial property, that prepared by rupturing C60 cage (i.e., C60-GQD) effectively kills Staphylococcus aureus, including its antibiotic-tolerant persisters, but not Bacillus subtilis, Escherichia coli, or Pseudomonas aeruginosa. The observed activity may correlate with a GQD's ability to disrupt bacterial cell envelop. Surface-Gaussian-curvature match between a GQD and a target bacterium may play critical role in the association of the GQD with bacterial cell surface, the initial step for cell envelope disruption, suggesting the importance of both GQDs' source materials and bacterial shape.


Assuntos
Antibacterianos/farmacologia , Grafite/química , Pontos Quânticos/química , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Microscopia de Força Atômica , Staphylococcus aureus/efeitos dos fármacos
9.
ACS Biomater Sci Eng ; 2(12): 2127-2132, 2016 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-33465888

RESUMO

"On-demand" drug release within target site is critical for targeted drug delivery systems. We herein integrate the advantages of upper critical solution temperature (UCST) polymers, photothermal agent, and red blood cell (RBC) membrane coating into a single drug delivery nanosystem and, for the first time, achieve remotely controlled UCST polymer-based drug delivery system that undergoes "on-demand" drug release within specified zone. When in laser-off state, the resulting nanosystem demonstrates significantly diminished drug self-leakage, owing to shielding by the RBC membrane coating. Upon laser irradiation, this system undergoes responsive drug release, likely because of particle swelling due to its UCST polymer component's hydrophobic-to-hydrophilic transition triggered by the rapid localized heating generated by its preloaded photothermal agent via photothermal effects. As a result, this drug delivery system exhibits spatiotemporally controlled cytotoxicity to cultured cells, efficiently eradicating irradiated cancerous cells without appreciably impacting nonirradiated ones, those ∼0.7 cm away from the irradiation zone. This work may open an avenue to thermosensitive drug delivery systems potentially "ideal" for intravenous administration and inspire future efforts on biomedical applications of UCST polymers.

10.
ACS Appl Mater Interfaces ; 7(50): 27602-7, 2015 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-26632646

RESUMO

Net cationicity of membrane-disruptive antimicrobials is necessary for their activity but may elicit immune attack when administered intravenously. By cloaking a dendritic polycation (G2) with poly(caprolactone-b-ethylene glycol) (PCL-b-PEG), we obtain a nanoparticle antimicrobial, G2-g-(PCL-b-PEG), which exhibits neutral surface charge but kills >99.9% of inoculated bacterial cells at ≤8 µg/mL. The observed activity may be attributed PCL's responsive degradation by bacterial lipase and the consequent exposure of the membrane-disruptive, bactericidal G2 core. Moreover, G2-g-(PCL-b-PEG) exhibits good colloidal stability in the presence of serum and insignificant hemolytic toxicity even at ≥2048 µg/mL. suggesting good blood compatibility required for intravenous administration.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/efeitos dos fármacos , Dendrímeros/farmacologia , Etilenoglicóis/farmacocinética , Poliésteres/farmacocinética , Peptídeos Catiônicos Antimicrobianos/química , Bactérias/patogenicidade , Dendrímeros/química , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Etilenoglicóis/química , Humanos , Lipase/antagonistas & inibidores , Lipase/química , Nanopartículas/química , Poliésteres/química , Proteólise/efeitos dos fármacos
11.
ACS Appl Mater Interfaces ; 7(19): 10511-7, 2015 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-25906148

RESUMO

We report an antibacterial surface that kills airborne bacteria on contact upon minutes of solar near-infrared (NIR) irradiation. This antibacterial surface employs reduced graphene oxide (rGO), a well-known near-infrared photothermal conversion agent, as the photosensitizer and is prepared by assembling oppositely charged polyelectrolyte-stabilized rGO sheets (PEL-rGO) on a quartz substrate with the layer-by-layer (LBL) technique. Upon solar irradiation, the resulting PEL-rGO LBL multilayer efficiently generates rapid localized heating and, within minutes, kills >90% airborne bacteria, including antibiotic-tolerant persisters, on contact, likely by permeabilizing their cellular membranes. The observed activity is retained even when the PEL-rGO LBL multilayer is placed underneath a piece of 3 mm thick pork tissue, indicating that solar light in the near-infrared region plays dominant roles in the observed activity. This work may pave the way toward NIR-light-activated antibacterial surfaces, and our PEL-rGO LBL multilayer may be a novel surface coating material for conveniently disinfecting biomedical implants and common objects touched by people in daily life in the looming postantibiotic era with only minutes of solar exposure.


Assuntos
Fenômenos Fisiológicos Bacterianos/efeitos da radiação , Desinfecção/métodos , Grafite/química , Grafite/efeitos da radiação , Energia Solar , Sobrevivência Celular/efeitos da radiação , Materiais Revestidos Biocompatíveis/síntese química , Materiais Revestidos Biocompatíveis/efeitos da radiação , Eletrólitos/química , Eletrólitos/efeitos da radiação , Excipientes/química , Excipientes/efeitos da radiação , Raios Infravermelhos , Teste de Materiais , Membranas Artificiais , Oxirredução/efeitos da radiação , Óxidos/química , Óxidos/efeitos da radiação , Propriedades de Superfície/efeitos dos fármacos
12.
Int J Mol Sci ; 15(11): 20339-54, 2014 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-25383677

RESUMO

Here, three novel cholesterol (Ch)/low molecular weight polyethylene glycol (PEG) conjugates, termed α, ω-cholesterol-functionalized PEG (Ch2-PEGn), were successfully synthesized using three kinds of PEG with different average molecular weight (PEG600, PEG1000 and PEG2000). The purpose of the study was to investigate the potential application of novel cationic liposomes (Ch2-PEGn-CLs) containing Ch2-PEGn in gene delivery. The introduction of Ch2-PEGn affected both the particle size and zeta potential of cationic liposomes. Ch2-PEG2000 effectively compressed liposomal particles and Ch2-PEG2000-CLs were of the smallest size. Ch2-PEG1000 and Ch2-PEG2000 significantly decreased zeta potentials of Ch2-PEGn-CLs, while Ch2-PEG600 did not alter the zeta potential due to the short PEG chain. Moreover, the in vitro gene transfection efficiencies mediated by different Ch2-PEGn-CLs also differed, in which Ch2-PEG600-CLs achieved the strongest GFP expression than Ch2-PEG1000-CLs and Ch2-PEG2000-CLs in SKOV-3 cells. The gene delivery efficacy of Ch2-PEGn-CLs was further examined by addition of a targeting moiety (folate ligand) in both folate-receptor (FR) overexpressing SKOV-3 cells and A549 cells with low expression of FR. For Ch2-PEG1000-CLs and Ch2-PEG2000-CLs, higher molar ratios of folate ligand resulted in enhanced transfection efficacies, but Ch2-PEG600-CLs had no similar in contrast. Additionally, MTT assay proved the reduced cytotoxicities of cationic liposomes after modification by Ch2-PEGn. These findings provide important insights into the effects of Ch2-PEGn on cationic liposomes for delivering genes, which would be beneficial for the development of Ch2-PEGn-CLs-based gene delivery system.


Assuntos
Cátions/química , Colesterol/análogos & derivados , Técnicas de Transferência de Genes , Lipossomos/química , Polietilenoglicóis/química , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Colesterol/síntese química , Colesterol/química , Colesterol/toxicidade , Fluorescência , Receptor 1 de Folato/metabolismo , Ácido Fólico/química , Humanos , Ligantes , Espectrometria de Massas , Peso Molecular , Tamanho da Partícula , Espectroscopia Fotoeletrônica , Polietilenoglicóis/síntese química , Polietilenoglicóis/toxicidade , Espectroscopia de Prótons por Ressonância Magnética , Eletricidade Estática , Transfecção , Temperatura de Transição
13.
ACS Appl Mater Interfaces ; 6(15): 13183-90, 2014 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-25026597

RESUMO

There are significant controversies on the antibacterial properties of graphene oxide (GO): GO was reported to be bactericidal in saline, whereas its activity in nutrient broth was controversial. To unveil the mechanisms underlying these contradictions, we performed antibacterial assays under comparable conditions. In saline, bare GO sheets were intrinsically bactericidal, yielding a bacterial survival percentage of <1% at 200 µg/mL. Supplementing saline with ≤10% Luria-Bertani (LB) broth, however, progressively deactivated its bactericidal activity depending on LB-supplementation ratio. Supplementation of 10% LB made GO completely inactive; instead, ∼100-fold bacterial growth was observed. Atomic force microscopy images showed that certain LB components were adsorbed on GO basal planes. Using bovine serum albumin and tryptophan as well-defined model adsorbates, we found that noncovalent adsorption on GO basal planes may account for the deactivation of GO's bactericidal activity. Moreover, this deactivation mechanism was shown to be extrapolatable to GO's cytotoxicity against mammalian cells. Taken together, our observations suggest that bare GO intrinsically kills both bacteria and mammalian cells and noncovalent adsorption on its basal planes may be a global deactivation mechanism for GO's cytotoxicity.


Assuntos
Antibacterianos/farmacologia , Grafite/química , Grafite/farmacologia , Óxidos/química , Óxidos/farmacologia , Animais , Bacillus subtilis/efeitos dos fármacos , Bovinos , Escherichia coli/efeitos dos fármacos , Células Hep G2 , Humanos , Testes de Sensibilidade Microbiana , Microscopia de Fluorescência , Soroalbumina Bovina/química , Cloreto de Sódio
14.
Biomacromolecules ; 15(9): 3267-77, 2014 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-25068991

RESUMO

We show that simply converting the hydrophobic moiety of an antimicrobial peptide (AMP) or synthetic mimic of AMPs (SMAMP) into a hydrophilic one could be a different pathway toward membrane-active antimicrobials preferentially acting against bacteria over host cells. Our biostatistical analysis on natural AMPs indicated that shorter AMPs tend to be more hydrophobic, and the hydrophilic-and-cationic mutants of a long AMP experimentally demonstrated certain membrane activity against bacteria. To isolate the effects of antimicrobials' hydrophobicity and systematically examine whether hydrophilic-and-cationic mutants could inherit the membrane activity of their parent AMPs/SMAMPs, we constructed a minimal prototypical system based on methacrylate-based polymer SMAMPs and compared the antibacterial membrane activity and hemolytic toxicity of analogues with and without the hydrophobic moiety. Antibacterial assays showed that the hydrophobic moiety of polymer SMAMPs consistently promoted the antibacterial activity but diminished in effectiveness for long polymers, and the resultant long hydrophilic-and-cationic polymers were also membrane active against bacteria. What distinguished these long mutants from their parent SMAMPs were their drastically reduced hemolytic toxicities and, as a result, strikingly enhanced selectivity. Similar toxicity reduction was observed with the hydrophilic-and-cationic mutants of long AMPs. Taken together, our results suggest that long hydrophilic-and-cationic polymers could offer preferential membrane activity against bacteria over host cells, which may have implications in future antimicrobial development.


Assuntos
Anti-Infecciosos , Peptídeos Catiônicos Antimicrobianos , Bactérias/crescimento & desenvolvimento , Materiais Biomiméticos , Membrana Eritrocítica/química , Viabilidade Microbiana/efeitos dos fármacos , Animais , Anti-Infecciosos/síntese química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/síntese química , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Bactérias/química , Materiais Biomiméticos/síntese química , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Membrana Eritrocítica/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Ácidos Polimetacrílicos/síntese química , Ácidos Polimetacrílicos/química , Ácidos Polimetacrílicos/farmacologia
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