14 research outputs found
Surfaces with Dual Functionality through Specific Coimmobilization of Self-Assembled Polymeric Nanostructures
Coimmobilization of functional, nanosized assemblies broadens the possibility to engineer dually functionalized active surfaces with a nanostructured texture. Surfaces decorated with different nanoassemblies, such as micelles, polymersomes, or nanoparticles are in high demand for various applications ranging from catalysis, biosensing up to antimicrobial surfaces. Here, we present a combination of bio-orthogonal and catalyst-free strain-promoted azide–alkyne click (SPAAC) and thiol–ene reactions to simultaneously coimmobilize various nanoassemblies; we selected polymersome–polymersome and polymersome–micelle assemblies. For the first time, the immobilization method using SPAAC reaction was studied in detail to attach soft, polymeric assemblies on a solid support. Together, the SPAAC and thiol–ene reactions successfully coimmobilized two unique self-assembled structures on the surfaces. Additionally, poly(dimethylsiloxane) (PDMS)-based polymersomes were used as “ink” for direct immobilization from a PDMS-based microstamp onto a surface creating locally defined patterns. Combining immobilization reactions has the advantage to attach any kind of nanoassembly pairs, resulting in surfaces with “desired” interfacial properties. Different nanoassemblies that encapsulate multiple active compounds coimmobilized on a surface will pave the way for the development of multifunctional surfaces with controlled properties and efficiency
Bio-catalytic nanocompartments for in situ production of glucose-6-phosphate
Cells are sophisticated biocatalytic systems driving a complex network of biochemical reactions. A bioinspired strategy to create advanced functional systems is to design confined spaces for complex enzymatic reactions by using a combination of synthetic polymer assemblies and natural cell components. Here, we developed bio-catalytic nanocompartments that contain phosphoglucomutase protected by a biomimetic polymer membrane, which was permeabilized for reactants through insertion of an engineered α-hemolysin pore protein. These bio-catalytic nanocompartments serve for production of glucose-6-phosphate, and thus possess great potential for applications in an incomplete glycolysis, pentose phosphate pathway, or in plant biological reactions
Biomimetic Planar Polymer Membranes Decorated with Enzymes as Functional Surfaces
Functional surfaces were generated by a combination of enzymes with polymer membranes composed of an amphiphilic, asymmetric block copolymer poly(ethyleneglycol)-block-poly(γ-methyl-ε-caprolactone)-block-poly[(2-dimethylamino)ethylmethacrylate]. First, polymer films formed at the air–water interface were transferred in different sequences onto silica solid support using the Langmuir–Blodgett technique, generating homogeneous monolayers and bilayers. A detailed characterization of these films provided insight into their properties (film thickness, wettability, topography, and roughness). On the basis of these findings, the most promising membranes were selected for enzyme attachment. Functional surfaces were then generated by the adsorption of two model enzymes that can convert phenol and its derivatives (laccase and tyrosinase), well known as high-risk pollutants of drinking and natural water. Both enzymes preserved their activity upon immobilization with respect to their substrates. Depending on the properties of the polymer films, different degrees of enzymatic activity were observed: bilayers provided the best conditions in terms of both overall stability and enzymatic activity. The interaction between amphiphilic triblock copolymer films and enzymes is exploited to engineer “active surfaces” with specific functionalities and high efficacy resulting from the intrinsic activity of the biomolecules that is preserved by an appropriate synthetic environment
Surfaces Decorated with Polymeric Nanocompartments for pH Reporting
Here we present a novel active surface that demonstrates pH responsiveness and can be used as a platform for designing smart labels`. To generate our active surfaces, we immobilized polymer nanocompartments onto glass surfaces using thiol-ene chemistry. Prior to surface attachment, a pH responsive model dye was encapsulated within nanocompartments at two different pH values. We confirmed the attachment and distribution of dye-loaded polymersomes and established the pH responsiveness of the active surface construct. The strategy presented here was carefully chosen to obtain small sized functional surfaces from commercially available materials that can be easily integrated into intelligent packaging systems. The ability to miniaturize such smart labels, while still being able to detect their response to the environment, is a crucial step towards developing active surfaces suitable for food packaging applications
Expanding the potential of MRI contrast agents through multifunctional polymeric nanocarriers
MRI is a sought-after, noninvasive tool in medical diagnostics, yet the direct application of contrast agents to tissue suffers from several drawbacks. Hosting the contrast agents in polymeric nanocarriers can solve many of these issues while creating additional benefit through exploitation of the intrinsic characteristics of the polymeric carriers. In this report, the versatility is highlighted with recent examples of dendritic and hyperbranched polymers, polymer nanoparticles and micelles, and polymersomes as multifunctional bioresponsive nanocarriers for MRI contrast agents
Polymeric 3D nano-architectures for transport and delivery of therapeutically relevant biomacromolecules
A promising approach for addressing a range of diseases lies in the delivery of functional biomacromolecules such as nucleic acids or proteins to cells. Polymers, peptides and the different shapes accessible through self-assembly of polymeric and peptidic amphiphiles have been widely explored as carriers and as containers for reactions on the nanoscale. These building blocks are particularly interesting, because several essential parameters such as physical characteristics, conditions for degradation or biocompatibility can be tuned to suit specific requirements. In this review, different three-dimensional architectures ranging from dendrimers and hyperbranched molecules to micelles, vesicles and nanoparticles assembled from synthetic polymers and peptides are discussed. It is focused on their function as a carrier for biologically active macromolecules, highlighting seminal examples from the current literature and pointing out the remaining and upcoming challenges in this important area of researc
Biomimetic Planar Polymer Membranes Decorated with Enzymes as Functional Surfaces
Functional
surfaces were generated by a combination of enzymes
with polymer membranes composed of an amphiphilic, asymmetric block
copolymer polyÂ(ethyleneglycol)-<i>block</i>-polyÂ(Îł-methyl-ε-caprolactone)-<i>block</i>-polyÂ[(2-dimethylamino)Âethylmethacrylate]. First, polymer
films formed at the air–water interface were transferred in
different sequences onto silica solid support using the Langmuir–Blodgett
technique, generating homogeneous monolayers and bilayers. A detailed
characterization of these films provided insight into their properties
(film thickness, wettability, topography, and roughness). On the basis
of these findings, the most promising membranes were selected for
enzyme attachment. Functional surfaces were then generated by the
adsorption of two model enzymes that can convert phenol and its derivatives
(laccase and tyrosinase), well known as high-risk pollutants of drinking
and natural water. Both enzymes preserved their activity upon immobilization
with respect to their substrates. Depending on the properties of the
polymer films, different degrees of enzymatic activity were observed:
bilayers provided the best conditions in terms of both overall stability
and enzymatic activity. The interaction between amphiphilic triblock
copolymer films and enzymes is exploited to engineer “active
surfaces” with specific functionalities and high efficacy resulting
from the intrinsic activity of the biomolecules that is preserved
by an appropriate synthetic environment