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2.
Mater Sci Eng C Mater Biol Appl ; 116: 111109, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32806230

RESUMO

Implant-associated infections present severe and difficult-to-treat complications after surgery, related to implant biofilm colonization. Systemic administration of antibiotics cannot reach sufficient concentrations at the infected site and may be toxic. Here we describe how mussel-inspired dendritic material coated on a titanium surface can locally activate a prodrug of daptomycin (pro-dapto) to treat methicillin-resistant Staphylococcus aureus. The mechanism of the prodrug activation is based on bio-orthogonal click chemistry between a tetrazine (Tz) and trans-cyclooctene (TCO). The former is attached to the dendritic polymer, while the later converts daptomycin into a prodrug. Characterization of the material's properties revealed that it is hydrophobic, non-toxic, and stable for a prolonged period of time. We envision that the titanium coated dendritic material will be able to improve the treatment of implant-associated infections by concentrating systemically administered antibiotic prodrugs, thus converting them into active localized medicines.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Staphylococcus aureus , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Biofilmes , Materiais Revestidos Biocompatíveis/farmacologia , Humanos , Polímeros , Infecções Estafilocócicas/tratamento farmacológico , Titânio/farmacologia
3.
Chemistry ; 24(30): 7742-7748, 2018 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-29578259

RESUMO

Dynamic regulation of the interactions between specific molecules on functional surfaces and biomolecules, for example, proteins or cells, is critical for biosensor and biomedical devices. Herein, we present a spiropyran (SP)-based light-responsive surface coating, hPG (hyperbranched polyglycerol)-SP, to control the adsorption of proteins and adhesion of cells. In the normal state, the SP groups on the coating surface were in hydrophobic ring-closed form, which promotes the nonspecific protein adsorption and cell adhesion. Under UV irradiation, the grafted SP groups were dynamically isomerized into hydrophilic/zwitterionic merocyanine. Both hydrophilicity and zwitterions support the formation of a hydrated layer and hence the resulting hPG-MC coatings highly resist protein adsorption and cell adhesion. Moreover, the presented hPG also provided a robust bioinert background to suppress the nonspecific protein adsorption and cells adhesion. Therefore, this functionalized coating exhibited a good photoregulated antifouling behavior. Moreover, the detachment of adsorbed proteins and adhered cells from the coating surface was also realized.


Assuntos
Benzopiranos/química , Materiais Revestidos Biocompatíveis/química , Glicerol/química , Indóis/química , Nitrocompostos/química , Polímeros/química , Proteínas/química , Adsorção , Adesão Celular , Interações Hidrofóbicas e Hidrofílicas , Propriedades de Superfície
4.
ACS Appl Mater Interfaces ; 9(51): 44281-44292, 2017 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-29188709

RESUMO

A new "adsorption-cross-linking" technology is presented to generate a highly dense polymer brush coating on various nonpolar substrates, including the most inert and low-energy surfaces of poly(dimethylsiloxane) and poly(tetrafluoroethylene). This prospective surface modification strategy is based on a tailored bifunctional amphiphilic block copolymer with benzophenone units as the hydrophobic anchor/chemical cross-linker and terminal azide groups for in situ postmodification. The resulting polymer brushes exhibited long-term and ultralow protein adsorption and cell adhesion benefiting from the high density and high hydration ability of polyglycerol blocks. The presented antifouling brushes provided a highly stable and robust bioinert background for biospecific adsorption of desired proteins and bacteria after secondary modification with bioactive ligands, e.g., mannose for selective ConA and Escherichia coli binding.


Assuntos
Polímeros/química , Adsorção , Adesão Celular , Reagentes de Ligações Cruzadas , Interações Hidrofóbicas e Hidrofílicas , Estudos Prospectivos , Propriedades de Superfície
5.
ACS Appl Mater Interfaces ; 9(40): 35411-35418, 2017 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-28914053

RESUMO

A novel surface coating with durable broad-spectrum antibacterial ability was prepared based on mussel-inspired dendritic polyglycerol (MI-dPG) embedded with copper nanoparticles (Cu NPs). The functional surface coating is fabricated via a facile dip-coating process followed by in situ reduction of copper ions with a MI-dPG coating to introduce Cu NPs into the coating matrix. This coating has been demonstrated to possess efficient long-term antibacterial properties against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and kanamycin-resistant E. coli through an "attract-kill-release" strategy. The synergistic antibacterial activity of the coating was shown by the combination of two functions of the contact killing, reactive oxygen species production and Cu ions released from the coating. Furthermore, this coating inhibited biofilm formation and showed good compatibility to eukaryotic cells. Thus, this newly developed Cu NP-incorporated MI-dPG surface coating may find potential application in the design of antimicrobial coating, such as implantable devices.

6.
Langmuir ; 33(38): 9508-9520, 2017 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-28605191

RESUMO

Facile approaches to substrate-independent surface coatings with special wettability properties, such as superhydrophobicity, superhydrophilicity, and superamphiphobicity, have been limited. To address this problem, we combined two separate biomimetic concepts of mussel-inspired adhesion and highly hierarchical lotuslike surface structures to develop a universal fabrication method for various superwetting systems on any kind of material. In this feature article, we summarize our work on mussel-inspired polyglycerol (MI-dPG) and its application in the area of superwetting interfacial materials. MI-dPG mimics not only the functional groups of mfp-5 but also their molecular weight and molecular structure, which results in strong and rapid adhesion to the substrate. Furthermore, the MI-dPG coating process provides precise roughness control. The construction of highly hierarchical and superhydrophilic structures was achieved either directly by pH-controlled aggregation or in combination with nanoparticles. Subsequent postmodification of these highly hierarchical structures with different fluorinated or nonfluorinated hydrophobic molecules yielded a surface with superhydrophobic and even superamphiphobic properties.

7.
ACS Appl Mater Interfaces ; 9(7): 6624-6633, 2017 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-28118539

RESUMO

Despite the increasing need for universal polymer coating strategies, only a few approaches have been successfully developed, and most of them are suffering from color, high thickness, or high roughness. In this paper, we present for the first time a universal monolayer coating that is only a few nanometers thick and independent of the composition, size, shape, and structure of the substrate. The coating is based on a bioinspired synthetic amphiphilic block copolymer that combines two concepts from blood protein adsorption and mussel adhesion. This polymer can be rapidly tethered on various substrates including both planar surfaces and nanosystems with high grafting density. The resulting monolayer coatings are, on the one hand, inert to the adsorption of multiple polymer layers and prevent biofouling. On the other hand, they are chemically active for secondary functionalization and provide a new platform for selective material surface modification.


Assuntos
Proteínas Sanguíneas/química , Adsorção , Animais , Incrustação Biológica , Bivalves , Polímeros , Propriedades de Superfície
8.
ACS Appl Mater Interfaces ; 8(42): 29117-29127, 2016 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-27714994

RESUMO

Facile approaches for the fabrication of substrate independent superamphiphobic surfaces that can repel both water and organic liquids have been limited. The design of such super-repellent surfaces is still a major challenge of surface chemistry and physics. Herein, we describe a simple and efficient dip-coating approach for the fabrication of highly hierarchical surface coatings with superamphiphobic properties for a broad range of materials based on a mussel-inspired dendritic polymer (MI-dPG). The MI-dPG coating process provides a precise roughness control, and the construction of highly hierarchical structures was achieved either directly by pH-controlled aggregation or in combination with nanoparticles (NP). Moreover, the fabrication of coatings with a thickness and roughness gradient was possible via simple adjustment of the depth of the coating solution. Subsequent postmodification of these highly hierarchical structures with fluorinated molecules yielded a surface with superamphiphobic properties that successfully prevented the wetting of liquids with a low surface tension down to about 30 mN/m. The generated superamphiphobic coatings exhibit impressive repellency to water, surfactant containing solutions, and biological liquids, such as human serum, and are flexible on soft substrates.

9.
Adv Mater ; 26(43): 7358-64, 2014 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-25236438

RESUMO

Supramolecular polymerization for non-wetting surface coatings is described. The self-assembly of low-molecular-weight gelators (LMWGs) with perfluorinated side chains can be utilized to rapidly construct superhydrophobic, as well as liquid-infused slippery surfaces within minutes. The lubricated slippery surface exhibits impressive repellency to biological li-quids, such as human serum and blood, and very fast self-healing.


Assuntos
Polímeros/química , Amidinas/síntese química , Amidinas/química , Materiais Biomiméticos/química , Caryophyllaceae , Cicloexanos/síntese química , Cicloexanos/química , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Lipídeos/química , Lubrificação/métodos , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Micro-Ondas , Estrutura Molecular , Polímeros/síntese química , Propriedades de Superfície , Água/química
10.
Org Biomol Chem ; 12(3): 503-10, 2014 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-24280910

RESUMO

A chiral, crown-ether-functionalized bisurea gelator forms supramolecular gels in ionic liquids. The resulting ionogels show a remarkably high thermal stability with gel-sol transition temperatures (T(gs)) reaching more than 100 °C. The mechanical strength of these ionogels is surprisingly high and even comparable to that of cross-linked protein fibres. Furthermore, the ionogels exhibit rapid self-recovery properties after structural damage caused by deformation. Pseudorotaxanes form from the gelators' benzo[21]crown-7 ethers as the wheels and secondary ammonium ions as the axles despite the competition between that cation and the imidazolium ions of the ionic liquid for crown ether binding. Pseudorotaxane formation as an external chemical stimulus triggers the gel-sol transition of the ionogels.

11.
Chemistry ; 19(44): 14867-75, 2013 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-24105808

RESUMO

Noncovalent dendrimer-dendrimer complexes were successfully ionized by electrospray ionization of partly protonated amino-terminated polypropylene amine (POPAM) and POPAM dendrimers fully functionalized with benzo[21]crown-7 on all branches. Hydrogen/deuterium exchange (HDX) experiments conducted on dendrimer-dendrimer complexes in the high vacuum of a mass spectrometer give rise to a complete exchange of all labile NH hydrogen atoms. As crown ethers represent noncovalent protective groups against HDX reactions on the ammonium group to which they are coordinated, this result provides evidence for a very dynamic binding situation: each crown is mobile enough to move from one ammonium binding site to another. Schematically, one might compare this motion with two rock 'n' roll dancers that swirl around each other without completely losing all contact at any time. Although the multivalent attachment certainly increases the overall affinity, the "microdynamics" of individual site binding and dissociation remains fast.

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