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1.
J Am Chem Soc ; 146(17): 12130-12137, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38642054

RESUMO

Supramolecular polymers display interesting optoelectronic properties and, thus, deploy multiple applications based on their molecular arrangement. However, controlling supramolecular interactions to achieve a desirable molecular organization is not straightforward. Over the past decade, light-matter strong coupling has emerged as a new tool for modifying chemical and material properties. This novel approach has also been shown to alter the morphology of supramolecular organization by coupling the vibrational bands of solute and solvent to the optical modes of a Fabry-Perot cavity (vibrational strong coupling, VSC). Here, we study the effect of VSC on the supramolecular polymerization of chiral zinc-porphyrins (S-Zn) via a cooperative effect. Electronic circular dichroism (ECD) measurements indicate that the elongation temperature (Te) of the supramolecular polymerization is lowered by ∼10 °C under VSC. We have also generalized this effect by exploring other supramolecular systems under strong coupling conditions. The results indicate that the solute-solvent interactions are modified under VSC, which destabilizes the nuclei of the supramolecular polymer at higher temperatures. These findings demonstrate that the VSC can indeed be used as a tool to control the energy landscape of supramolecular polymerization. Furthermore, we use this unique approach to switch between the states formed under ON- and OFF-resonance conditions, achieved by simply tuning the optical cavity in and out of resonance.

2.
Chemistry ; 30(8): e202303107, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38009432

RESUMO

Here, we report on the synthesis of discrete oligomers of alkyl-bridged naphthalenediimides (NDIs) and study their molecular nanostructures both in bulk, in solution, and at the liquid-solid interface. Via an iterative synthesis method, multiple NDI cores were bridged with short and saturated alkyl-diamines (C3 and C12 ) or long and unsaturated alkyl-diamines (u2 C33 to u8 C100 ) at their imide termini. The strong intermolecular interaction between the NDI cores was observed by probing their photophysical properties in solution. In bulk, the discrete NDI oligomers preferentially ordered in lamellar morphologies, irrespective of whether a saturated or unsaturated spacer was employed. Moreover, both the molecular architecture as well as the crystallization conditions play a significant role in the nanoscale ordering. The long unsaturated alkyl chains lead preferably to folded-chain conformations while their saturated analogues form stretched arrangements. At the solution-solid interface, well-defined lamellar regions were observed. These results show that precision in chemical structure alone is not sufficient to reach well-defined structures of discrete oligomers, but that it must be combined with precision in processing conditions.

3.
J Am Chem Soc ; 143(10): 4032-4042, 2021 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-33660998

RESUMO

Discrete block co-oligomers (BCOs) assemble into highly ordered nanostructures, which adopt a variety of morphologies depending on their environment. Here, we present a series of discrete oligodimethylsiloxane-oligoproline (oDMS-oPro) BCOs with varying oligomer lengths and proline end-groups, and study the nanostructures formed in both bulk and solution. The conjugation of oligoprolines to apolar siloxanes permits a study of the aggregation behavior of oligoproline moieties in a variety of solvents, including a highly apolar solvent like methylcyclohexane. The apolar solvent is more reminiscent of the polarity of the siloxane bulk, which gives insights into the supramolecular interactions that govern both bulk and solution assembly processes of the oligoproline. This extensive structural characterization allows the bridging of the gap between solution and bulk assembly. The interplay between the aggregation of the oligoproline block and the phase segregation induced by the siloxane drives the assembly. This gives rise to disordered, micellar microstructures in apolar solution and crystallization-driven lamellar nanostructures in the bulk. While most di- and triblock co-oligomers adopt predictable morphological features, one of them, oDMS15-oPro6-NH2, exhibits pathway complexity leading to gel formation. The pathway selection in the complex interplay between aggregation and phase segregation gives rise to interesting material properties.


Assuntos
Oligopeptídeos/química , Polímeros/química , Prolina/química , Siloxanas/química , Soluções/química , Dicroísmo Circular , Cristalização , Nanoestruturas/química , Oligopeptídeos/metabolismo , Polímeros/metabolismo
4.
Biomacromolecules ; 22(12): 5363-5373, 2021 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-34846847

RESUMO

Dynamic binding events are key to arrive at functionality in nature, and these events are often governed by electrostatic or hydrophobic interactions. Synthetic supramolecular polymers are promising candidates to obtain biomaterials that mimic this dynamicity. Here, we created four new functional monomers based on the benzene-1,3,5-tricarboxamide (BTA) motif. Choline or atropine groups were introduced to obtain functional monomers capable of competing with the cell wall of Streptococcus pneumoniae for binding of essential choline-binding proteins (CBPs). Atropine-functionalized monomers BTA-Atr and BTA-Atr3 were too hydrophobic to form homogeneous assemblies, while choline-functionalized monomers BTA-Chol and BTA-Chol3 were unable to form fibers due to charge repulsion. However, copolymerization of BTA-Chol3 with non-functionalized BTA-(OH)3 yielded dynamic fibers, similar to BTA-(OH)3. These copolymers showed an increased affinity toward CBPs compared to free choline due to multivalent effects. BTA-based supramolecular copolymers are therefore a versatile platform to design bioactive and dynamic supramolecular polymers with novel biotechnological properties.


Assuntos
Anti-Infecciosos , Streptococcus pneumoniae , Materiais Biocompatíveis/metabolismo , Colina/farmacologia , Polímeros/química , Streptococcus pneumoniae/metabolismo
5.
J Am Chem Soc ; 142(8): 4070-4078, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-31971383

RESUMO

Achieving long-range order with surface-supported supramolecular assemblies is one of the pressing challenges in the prospering field of non-covalent surface functionalization. Having access to defect-free on-surface molecular assemblies will pave the way for various nanotechnology applications. Here we report the synthesis of two libraries of naphthalenediimides (NDIs) symmetrically functionalized with long aliphatic chains (C28 and C33) and their self-assembly at the 1-phenyloctane/highly oriented pyrolytic graphite (1-PO/HOPG) interface. The two NDI libraries differ by the presence/absence of an internal double bond in each aliphatic chain (unsaturated and saturated compounds, respectively). All molecules assemble into lamellar arrangements, with the NDI cores lying flat and forming 1D rows on the surface, while the carbon chains separate the 1D rows from each other. Importantly, the presence of the unsaturation plays a dominant role in the arrangement of the aliphatic chains, as it exclusively favors interdigitation. The fully saturated tails, instead, self-assemble into a combination of either interdigitated or non-interdigitated diagonal arrangements. This difference in packing is spectacularly amplified at the whole surface level and results in almost defect-free self-assembled monolayers for the unsaturated compounds. In contrast, the monolayers of the saturated counterparts are globally disordered, even though they locally preserve the lamellar arrangements. The experimental observations are supported by computational studies and are rationalized in terms of stronger van der Waals interactions in the case of the unsaturated compounds. Our investigation reveals the paramount role played by internal double bonds on the self-assembly of discrete large molecules at the liquid/solid interface.

6.
Angew Chem Int Ed Engl ; 59(39): 17229-17233, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32584462

RESUMO

Understanding cell/material interactions is essential to design functional cell-responsive materials. While the scientific literature abounds with formulations of biomimetic materials, only a fraction of them focused on mechanisms of the molecular interactions between cells and material. To provide new knowledge on the strategies for materials/cell recognition and binding, supramolecular benzene-1,3,5-tricarboxamide copolymers bearing benzoxaborole moieties are anchored on the surface of human erythrocytes via benzoxaborole/sialic-acid binding. This interaction based on both dynamic covalent and non-covalent chemistries is visualized in real time by means of total internal reflection fluorescence microscopy. Exploiting this imaging method, we observe that the functional copolymers specifically interact with the cell surface. An optimal fiber affinity towards the cells as a function of benzoxaborole concentration demonstrates the crucial role of multivalency in these cell/material interactions.


Assuntos
Benzamidas/química , Materiais Biomiméticos/química , Ácidos Borônicos/química , Eritrócitos/química , Polímeros/química , Humanos , Substâncias Macromoleculares/química , Microscopia de Fluorescência , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
7.
J Am Chem Soc ; 141(38): 15456-15463, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31483637

RESUMO

Nanomaterials with highly ordered, one- or two-dimensional molecular morphologies have promising properties for adaptive materials. Here, we present the synthesis and structural characterization of dinitrohydrazone (hydz) functionalized oligodimethylsiloxanes (oDMSs) of discrete length, which form both 1- and 2D nanostructures by precisely controlling composition and temperature. The morphologies are highly ordered due to the discrete nature of the siloxane oligomers. Columnar, 1D structures are formed from the melt within a few seconds as a result of phase segregation in combination with π-π stacking of the hydrazones. By tuning the length of the siloxane, the synergy between these interactions is observed which results in a highly temperature sensitive material. Macroscopically, this gives a material that switches reversibly and fast between an ordered, solid and a disordered, liquid state at almost equal temperatures. Ordered, 2D lamellar structures are formed under thermodynamic control by cold crystallization of the hydrazones in the amorphous siloxane bulk via a slow process. We elucidate the 1- and 2D morphologies from the nanometer to molecular level by the combined use of solid state NMR and X-ray scattering. The exact packing of the hydrazone rods within the cylinders and lamellae surrounded the liquid-like siloxane matrix is clarified. These results demonstrate that controlling the assembly pathway in the bulk and with that, tuning the nanostructure dimensions and domain spacings, material properties are altered for applications in nanotechnology or thermoresponsive materials.

8.
J Am Chem Soc ; 139(42): 14869-14872, 2017 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-28994585

RESUMO

Crystallinity is seldomly utilized as part of the microphase segregation process in ultralow-molecular-weight block copolymers. Here, we show the preparation of two types of discrete, semicrystalline block co-oligomers, comprising an amorphous oligodimethylsiloxane block and a crystalline oligo-l-lactic acid or oligomethylene block. The self-assembly of these discrete materials results in lamellar structures with unforeseen uniformity in the domain spacing. A systematic introduction of dispersity reveals the extreme sensitivity of the microphase segregation process toward chain length dispersity in the crystalline block.

9.
J Am Chem Soc ; 138(17): 5693-8, 2016 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-27054381

RESUMO

Monodisperse oligodimethylsiloxanes end-functionalized with the hydrogen-bonding ureidopyrimidinone (UPy) motif undergo phase separation between their aromatic end groups and dimethylsiloxane midblocks to form ordered nanostructures with domain spacings of <5 nm. The self-assembly behavior of these well-defined oligomers resembles that of high degree of polymerization (N)-high block interaction parameter (χ) linear diblock copolymers despite their small size. Specifically, the phase morphology varies from lamellar to hexagonal to body-centered cubic with increasing asymmetry in molecular volume fraction. Mixing molecules with different molecular weights to give dispersity >1.13 results in disorder, showing importance of molecular monodispersity for ultrasmall ordered phase separation. In contrast, oligodimethylsiloxanes end-functionalized with an O-benzylated UPy derivative self-assemble into lamellar nanostructures regardless of volume fraction because of the strong preference of the end groups to aggregate in a planar geometry. Thus, these molecules display more classically liquid-crystalline self-assembly behavior where the lamellar bilayer thickness is determined by the siloxane midblock. Here the lamellar nanostructure is tolerant to molecular polydispersity. We show the importance of end groups in high χ-low N block molecules, where block-copolymer-like self-assembly in our UPy-functionalized oligodimethylsiloxanes relies upon the dominance of phase separation effects over directional end group aggregation.

10.
J Am Chem Soc ; 138(12): 4210-8, 2016 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-26999049

RESUMO

Most of the theoretical and computational descriptions of the phase behavior of block copolymers describe the chain ensembles of perfect and uniform polymers. In contrast, experimental studies on block copolymers always employ materials with disperse molecular makeup. Although most polymers are so-called monodisperse, they still have a molecular weight dispersity. Here, we describe the synthesis and properties of a series of discrete length diblock co-oligomers, based on oligo-dimethylsiloxane (oDMS) and oligo-lactic acid (oLA), diblock co-oligomers with highly noncompatible blocks. By utilizing an iterative synthetic protocol, co-oligomers with molar masses up to 6901 Da, ultralow molar mass dispersities (D ≤ 1.00002), and unique control over the co-oligomer composition are synthesized and characterized. This specific block co-oligomer required the development of a new divergent strategy for the oDMS structures by which both bis- and monosubstituted oDMS derivatives up to 59 Si-atoms became available. The incompatibility of the two blocks makes the final coupling more demanding the longer the blocks become. These optimized synthetic procedures granted access to multigram quantities of most of the block co-oligomers, useful to study the lower limits of block copolymer phase segregation in detail. Cylindrical, gyroid, and lamellar nanostructures, as revealed by DSC, SAXS, and AFM, were generated. The small oligomeric size of the block co-oligomers resulted in exceptionally small feature sizes (down to 3.4 nm) and long-range organization.

11.
J Am Chem Soc ; 138(19): 6217-23, 2016 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-27119732

RESUMO

A synthetic method for the end-functionalization of vinylidene fluoride oligomers (OVDF) via a radical reaction between terminal olefins and I-OVDF is described. The method shows a wide substrate scope and excellent conversions, and permits the preparation of different disc-shaped cores such as benzene-1,3,5-tricarboxamides (BTAs), perylenes bisimide (PBI), and phthalocyanines (Pc) bearing three to eight ferroelectric oligomers at their periphery. The formation, purity, OVDF conformation, and morphology of the final adducts has been assessed by a combination of techniques, such as NMR, size exclusion chromatography, differential scanning calorimetry, polarized optical microscopy, and atomic force microscopy. Finally, PBI-OVDF and Pc-OVDF materials show ferroelectric hysteresis behavior together with high remnant polarizations, with values as high as Pr ≈ 37 mC/m(2) for Pc-OVDF. This work demonstrates the potential of preparing a new set of ferroelectric materials simply by attaching OVDF oligomers to different small molecules. The use of carefully chosen small molecules paves the way to new functional materials in which ferroelectricity and electrical conductivity or light-harvesting properties coexist in a single compound.

12.
Chemistry ; 21(1): 377-85, 2015 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-25399508

RESUMO

The synthesis of C3 - and C2 -symmetric benzene-1,3,5-tricarboxamides (BTAs) containing well-defined oligodimethylsiloxane (oDMS) and/or alkyl side chains has been carried out. The influence of the bulkiness of the oDMS chains in the aggregation behavior of dilute solutions of the oDMS-BTAs in methylcyclohexane was studied by temperature-dependent UV spectroscopy. The formation of hierarchically self-assembled aggregates was observed at different BTA concentrations, the tendency of aggregation increases by shortening or removing oDMS chains. Chiral BTAs were investigated with circular dichroism (CD) spectroscopy, showing a stronger tendency to aggregate than the achiral ones. Majority rules experiments show a linear behavior consistent with the existence of a high mismatch penalty energy. The most efficient oDMS-BTAs organogelators have the ability to form stable organogels at 5 mg mL(-1) (0.75 wt %) in hexane. Solid-state characterization techniques indicate the formation of an intermolecular threefold hydrogen bonding between adjacent molecules forming thermotropic liquid crystals, exhibiting a hexagonal columnar organization from room temperature to above 150 °C. A decrease of the clearing temperatures was observed when increasing the number and length of the oligodimethylsiloxane chains. In addition to the three-fold hydrogen bonding that leads to columnar liquid crystalline phase, segregation between the oDMS and aliphatic chains takes place in the BTA functionalized with two alkyl and one oDMS chain leading to a superlattice within the hexagonal structure with potential applications in lithography.


Assuntos
Benzamidas/química , Dimetilpolisiloxanos/química , Nanoestruturas/química , Benzamidas/síntese química , Dicroísmo Circular , Géis/química , Espectrofotometria Ultravioleta , Estereoisomerismo , Temperatura
13.
Angew Chem Int Ed Engl ; 54(46): 13673-7, 2015 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-26377931

RESUMO

A double approach was followed in the search of novel inhibitors of the surface choline-binding proteins (CBPs) of Streptococcus pneumoniae (pneumococcus) with antimicrobial properties. First, a library of 49 rationally-designed esters of alkyl amines was screened for their specific binding to CBPs. The best binders, being esters of bicyclic amines (EBAs), were then tested for their in vitro effect on pneumococcal growth and morphology. Second, the efficiency of EBA-induced CBP inhibition was enhanced about 45,000-fold by multivalency effects upon synthesizing a poly(propylene imine) dendrimer containing eight copies of an atropine derivative. Both approaches led to compounds that arrest bacterial growth, dramatically decrease cell viability, and exhibit a protection effect in animal disease models, demonstrating that the pneumococcal CBPs are adequate targets for the discovery of novel antimicrobials that overcome the currently increasing antimicrobial resistance issues.


Assuntos
Aminas/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Ésteres/farmacologia , Infecções Pneumocócicas/tratamento farmacológico , Streptococcus pneumoniae/efeitos dos fármacos , Aminas/síntese química , Aminas/química , Animais , Antibacterianos/síntese química , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ésteres/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Streptococcus pneumoniae/citologia , Streptococcus pneumoniae/crescimento & desenvolvimento , Relação Estrutura-Atividade , Peixe-Zebra/embriologia , Peixe-Zebra/microbiologia
14.
Adv Mater ; 36(23): e2312791, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38413048

RESUMO

Spontaneous phase separation is a promising strategy for the development of novel electronic materials, as the resulting well-defined morphologies generally exhibit enhanced conductivity. Making these structures adaptive to external stimuli is challenging, yet crucial as multistate reconfigurable switching is essential for neuromorphic materials. Here, a modular and scalable approach is presented to obtain switchable phase-separated viologen-siloxane nanostructures with sub-5 nm features. The domain spacing, morphology, and conductivity of these materials can be tuned by ion exchange, repeated pulsed photoirradiation and electric stimulation. Counterion exchange triggers a postsynthetic modification in domain spacing of up to 10%. Additionally, in some cases, 2D to 1D order-order transitions are observed with the latter exhibiting a sevenfold decrease in conductivity with respect to their 2D lamellar counterparts. Moreover, the combination of the viologen core with tetraphenylborate counterions enables reversible and in situ reduction upon light irradiation. This light-driven reduction provides access to a continuum of conducting states, reminiscent of long-term potentiation. The repeated voltage sweeps improve the nanostructures alignment, leading to increased conductivity in a learning effect. Overall, these results highlight the adaptivity of phase-separated nanostructures for the next generation of organic electronics, with exciting applications in smart sensors and neuromorphic devices.

15.
J Mater Chem C Mater ; 12(18): 6637-6644, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38737516

RESUMO

Donor-acceptor polymeric semiconductors are crucial for state-of-the-art applications, such as electronic skin mimics. The processability, and thus solubility, of these polymers in benign solvents is critical and can be improved through side chain engineering. Nevertheless, the impact of novel side chains on backbone orientation and emerging device properties often remains to be elucidated. Here, we investigate the influence of elongated linear and branched discrete oligodimethylsiloxane (oDMS) side chains on solubility and device performance. Thereto, diketopyrrolopyrrole-thienothiophene polymers are equipped with various oDMS pendants (PDPPTT-Sin) and subsequently phase separated into lamellar domains. The introduction of a branching point in the siloxane significantly enhanced the solubility of the polymer, as a result of increased backbone distortion. Simultaneously, the charge carrier mobility of the polymers decreased by an order of magnitude upon functionalization with long and/or branched siloxanes. This work unveils the intricate balance between processability and device performance in organic semiconductors, which is key for the development of next-generation electronic devices.

16.
Chemistry ; 19(26): 8642-9, 2013 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-23649986

RESUMO

The amide bond is a versatile functional group and its directional hydrogen-bonding capabilities are widely applied in, for example, supramolecular chemistry. The potential of the thioamide bond, in contrast, is virtually unexplored as a structuring moiety in hydrogen-bonding-based self-assembling systems. We report herein the synthesis and characterisation of a new self-assembling motif comprising thioamides to induce directional hydrogen bonding. N,N',N''-Trialkylbenzene-1,3,5-tris(carbothioamide)s (thioBTAs) with either achiral or chiral side-chains have been readily obtained by treating their amide-based precursors with P2S5. The thioBTAs showed thermotropic liquid crystalline behaviour and a columnar mesophase was assigned. IR spectroscopy revealed that strong, three-fold, intermolecular hydrogen-bonding interactions stabilise the columnar structures. In apolar alkane solutions, thioBTAs self-assemble into one-dimensional, helical supramolecular polymers stabilised by three-fold hydrogen bonding. Concentration- and temperature-dependent self-assembly studies performed by using a combination of UV and CD spectroscopy demonstrated a cooperative supramolecular polymerisation mechanism and a strong amplification of supramolecular chirality. The high dipole moment of the thioamide bond in combination with the anisotropic shape of the resulting cylindrical aggregate gives rise to sufficiently strong depolarised light scattering to enable depolarised dynamic light scattering (DDLS) experiments in dilute alkane solution. The rotational and translational diffusion coefficients, D(trans) and D(rot), were obtained from the DDLS measurements, and the average length, L, and diameter, d, of the thioBTA aggregates were derived (L = 490 nm and d = 3.6 nm). These measured values are in good agreement with the value L(w) = 755 nm obtained from fitting the temperature-dependent CD data by using a recently developed equilibrium model. This experimental verification validates our common practice for determining the length of BTA-based supramolecular polymers from model fits to experimental CD data. The ability of thioamides to induce cooperative supramolecular polymerisation makes them effective and broadly applicable in supramolecular chemistry.


Assuntos
Polímeros/química , Tioamidas/química , Alcanos/química , Ligação de Hidrogênio , Polimerização , Polímeros/síntese química , Estereoisomerismo , Temperatura , Termodinâmica , Tioamidas/síntese química
17.
Chemotherapy ; 59(2): 138-42, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24051739

RESUMO

BACKGROUND: Pneumococcal virulence factors common to all serotypes, such as choline-binding proteins (CBPs), are promising therapeutic targets in pneumococcal infections. We studied the effect of a choline dendrimer with maximized binding affinity/specificity for CBPs on microglia-mediated pneumococcal phagocytosis. METHODS: Pneumoccocal cultures were exposed to dendrimers containing 8 choline end groups or amino groups as controls, either from the beginning of bacterial growth or at the late exponential phase. The effect of long/short co-incubation was assessed in terms of bacterial morphological changes and increase in bacterial uptake by primary microglial cultures. RESULTS: Inhibiting CBPs by micromolar concentrations of a choline dendrimer caused the formation of long pneumococcal chains that were readily phagocytosed by microglia. Enhanced phagocytosis was dendrimer dose-dependent. Long bacteria-dendrimer co-incubation (14 h) resulted in a higher bacterial uptake than short co-incubation (2 h; p < 0.001). CONCLUSIONS: Multivalent dendrimers containing choline end groups are promising antimicrobial agents for the management of pneumococcal diseases.


Assuntos
Anti-Infecciosos/farmacologia , Colina/química , Dendrímeros/farmacologia , Microglia/efeitos dos fármacos , Microglia/microbiologia , Fagocitose/efeitos dos fármacos , Streptococcus pneumoniae/metabolismo , Animais , Anti-Infecciosos/química , Proteínas de Bactérias/metabolismo , Células Cultivadas , Colina/metabolismo , Dendrímeros/química , Camundongos , Camundongos Endogâmicos C57BL , Microglia/citologia , Microglia/fisiologia , Ligação Proteica
18.
Adv Mater ; 35(47): e2303909, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37572294

RESUMO

Recruiting endogenous antibodies to the surface of cancer cells using antibody-recruiting molecules has the potential to unleash innate immune effector killing mechanisms against antibody-bound cancer cells. The affinity of endogenous antibodies is relatively low, and many currently explored antibody-recruiting strategies rely on targeting over-expressed receptors, which have not yet been identified in most solid tumors. Here, both challenges are addressed by functionalizing poly(propyleneimine) (PPI) dendrimers with both multiple dinitrophenyl (DNP) motifs, as anti-hapten antibody-recruiting motifs, and myristoyl motifs, as universal phospholipid cell membrane anchoring motifs, to recruit anti-hapten antibodies to cell surfaces. By exploiting the multivalency of the ligand exposure on the dendrimer scaffold, it is demonstrated that dendrimers featuring ten myristoyl and six DNP motifs exhibit the highest antibody-recruiting capacity in vitro. Furthermore, it is shown that treating cancer cells with these dendrimers in vitro marks them for phagocytosis by macrophages in the presence of anti-hapten antibodies. As a proof-of-concept, it is shown that intratumoral injection of these dendrimers in vivo in tumor-bearing mice results in the recruitment of anti-DNP antibodies to the cell surface in the tumor microenvironment. These findings highlight the potential of dendrimers as a promising class of novel antibody-recruiting molecules for use in cancer immunotherapy.


Assuntos
Dendrímeros , Animais , Camundongos , Anticorpos , Haptenos , Fagocitose , Dinitrobenzenos , Membrana Celular
19.
Adv Mater ; 35(25): e2300891, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37002556

RESUMO

Efficient energy transport over long distances is essential for optoelectronic and light-harvesting devices. Although self-assembled nanofibers of organic molecules are shown to exhibit long exciton diffusion lengths, alignment of these nanofibers into films with large, organized domains with similar properties remains a challenge. Here, it is shown how the functionalization of C3 -symmetric carbonyl-bridged triarylamine trisamide (CBT) with oligodimethylsiloxane (oDMS) side chains of discrete length leads to fully covered surfaces with aligned domains up to 125 × 70 µm2 in which long-range exciton transport takes place. The nanoscale morphology within the domains consists of highly ordered nanofibers with discrete intercolumnar spacings within a soft amorphous oDMS matrix. The oDMS prevents bundling of the CBT fibers, reducing the number of defects within the CBT columns. As a result, the columns have a high degree of coherence, leading to exciton diffusion lengths of a few hundred nanometers with exciton diffusivities (≈0.05 cm2 s-1 ) that are comparable to those of a crystalline tetracene. These findings represent the next step toward fully covered surfaces of highly aligned nanofibers through functionalization with oDMS.

20.
Mater Horiz ; 9(1): 294-302, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34611679

RESUMO

The assembly of donor-acceptor molecules via charge transfer (CT) interactions gives rise to highly ordered nanomaterials with appealing electronic properties. Here, we present the synthesis and bulk co-assembly of pyrene (Pyr) and naphthalenediimide (NDI) functionalized oligodimethylsiloxanes (oDMS) of discrete length. We tune the donor-acceptor interactions by connecting the pyrene and NDI to the same oligomer, forming a heterotelechelic block molecule (NDI-oDMSPyr), and to two separate oligomers, giving Pyr and NDI homotelechelic block molecules (Pyr-oDMS and NDI-oDMS). Liquid crystalline materials are obtained for binary mixtures of Pyr-oDMS and NDI-oDMS, while crystallization of the CT dimers occurred for the heterotelechelic NDI-oDMS-Pyr block molecule. The synergy between crystallization and phase-segregation coupled with the discrete length of the oDMS units allows for perfect order and sharp interfaces between the insulating siloxane and CT layers composed of crystalline CT dimers. We were able to tune the lamellar domain spacing and donor-acceptor CT interactions by applying pressures up to 6 GPa on the material, making the system promising for soft-material nanotechnologies. These results demonstrate the importance of the molecular design to tune the CT interactions and stability of a CT material.

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