An official website of the United States government
Charge and energy transport within living systems are fundamental processes that enable the autonomous function of excitable cells and tissues. To date, localized control of these transport processes has been enabled by genetic modification approaches to render light sensitivity to cells. Here, we present peptidic nanoassemblies as constituents of a cardiac biomaterial platform that leverages complementary sequence interactions to direct photoinduced energy transport at the cellular interface. Photophysical characterizations and conductivity measurements confirm the occurrence of energy/charge transfer and photocurrent generation upon optical excitation in both dry and electrolytic environments. Comparing an electrostatic sequence pair against a sequence-matched donor–acceptor coassembly, we demonstrate that the sequence design with charge complementarity shows more prominent photocurrent behavior. With the flanking bioadhesive units, the primary and stem cell–derived cardiomyocytes interfaced with covalently stabilized films of the optoelectronic nanostructures exhibited material-stimulated genotypic, structural, or functional cardiac features. Collectively, our findings introduce an optoelectronic cardiac biomaterial where coassembled peptide nanostructures are molecularly designed to induce light sensitivity in excitable cells without gene modification, influencing in vitro cardiac contractile behavior and expression of cardiac markers.
more »
« less
Selective Induction of Molecular Assembly to Tissue‐Level Anisotropy on Peptide‐Based Optoelectronic Cardiac Biointerfaces
Abstract The conduction efficiency of ions in excitable tissues and of charged species in organic conjugated materials both benefit from having ordered domains and anisotropic pathways. In this study, a photocurrent‐generating cardiac biointerface is presented, particularly for investigating the sensitivity of cardiomyocytes to geometrically comply to biomacromolecular cues differentially assembled on a conductive nanogrooved substrate. Through a polymeric surface‐templated approach, photoconductive substrates with symmetric peptide‐quaterthiophene (4T)‐peptide units assembled as 1D nanostructures on nanoimprinted polyalkylthiophene (P3HT) surface are developed. The 4T‐based peptides studied here can form 1D nanostructures on prepatterned polyalkylthiophene substrates, as directed by hydrogen bonding, aromatic interactions between 4T and P3HT, and physical confinement on the nanogrooves. It is observed that smaller 4T‐peptide units that can achieve a higher degree of assembly order within the polymeric templates serve as a more efficient driver of cardiac cytoskeletal anisotropy than merely presenting aligned ‐RGD bioadhesive epitopes on a nanotopographic surface. These results unravel some insights on how cardiomyocytes perceive submicrometer dimensionality, local molecular order, and characteristics of surface cues in their immediate environment. Overall, the work offers a cardiac patterning platform that presents the possibility of a gene modification‐free cardiac photostimulation approach while controlling the conduction directionality of the biotic and abiotic components.
more »
« less
- Award ID(s):
- 2011967
- PAR ID:
- 10507024
- Publisher / Repository:
- Wiley-VCH GmbH
- Date Published:
- Journal Name:
- Advanced Materials
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract The combination of multiple orthogonal interactions enables hierarchical complexity in self‐assembled nanoscale materials. Here, efficient supramolecular polymerization of DNA origami nanostructures is demonstrated using a multivalent display of small molecule host–guest interactions. Modification of DNA strands with cucurbit[7]uril (CB[7]) and its adamantane guest, yielding a supramolecular complex with an affinity of order 1010m−1, directs hierarchical assembly of origami monomers into 1D nanofibers. This affinity regime enables efficient polymerization; a lower‐affinity β‐cyclodextrin–adamantane complex does not promote extended structures at a similar valency. Finally, the utility of the high‐affinity CB[7]–adamantane interactions is exploited to enable responsive enzymatic actuation of origami nanofibers assembled using peptide linkers. This work demonstrates the power of high‐affinity CB[7]–guest recognition as an orthogonal axis to drive self‐assembly in DNA nanotechnology.more » « less
-
Abstract Initiated Chemical Vapor Deposition (iCVD) is a versatile and powerful technique for controlling the morphology of polymeric and hybrid thin films, with applications spanning from electronics to biomedical devices. This review highlights recent advancements in iCVD technology that enable precise morphological control from creating ultrasmooth films to self‐assembled nanostructures. Advances in reactor design now allow for in situ monitoring of key parameters, such as film thickness and surface imaging, providing real‐time insights into material morphology. Surface morphology is influenced by both the substrate and coating layer. For the former, iCVD offers significant advantages in creating defect‐free, conformal coatings over complex substrates, making it particularly well‐suited for flexible electronics, optical devices, and antifouling/antimicrobial biointerfaces. For the latter, iCVD has been leveraged for the fabrication of microstructured coatings that improve energy storage, gas sensing, and pathogen detection, superhydrophobic or anti‐icing surfaces. Its all‐dry processing and compatibility with temperature‐sensitive substrates further emphasize its potential for sustainable manufacturing. The ability to fine‐tune film chemistry and morphology, combined with the scalability, positions iCVD as a promising tool for addressing future technological challenges in advanced materials design.more » « less
-
Abstract Conjugated polymer brush (CPB) films are more robust and exhibit more vertically aligned polymer chains than their spun‐cast analogs. We prepare CPB films of poly(3‐hexylthiophene) (P3HT) by coupling an amine‐terminated surface (ATS) formed from (3‐aminopropyl)triethoxysilane (APTES) on Si/SiO2to 4‐bromobenzoic acid using standard, inexpensive peptide coupling reagents. The resulting terminal bromobenzene is reacted with Pd(PtBu3)2and immersed in the monomer solution. X‐ray photoelectron spectroscopy, spectroscopic ellipsometry and static water contact angle measurements confirm the surface chemistry at each stage of P3HT CPB preparation. Atomic force microscopy(AFM) and UV–vis spectrophotometry indicate that the CPB films prepared by this method exhibit similar morphology and optical properties to those produced from other methods of poly(3‐alkylthiophene) CPB film preparation. Variations of the standard approach, such as using a pre‐synthesized silane counterpart or with (11‐aminoundecyl)triethoxysilane, show comparable film morphologies by AFM. This method is used to produce the first CPB film of poly(3‐dodecylthiophene), showing its utility for exploring CPB films of more sterically demanding polymers. Peptide coupling is used to prepare an analogous functionalized thiol for initiating P3HT CPB film growth from Au surfaces, and microcontact printing with this thiol allows preparation of the first patterned CPB film of P3HT.more » « less
-
Abstract Cardiovascular disease continues to be the leading cause of death in the United States. A major contributing factor is cardiac arrhythmia, which results from irregular electrical activity in the heart. On a tissue level, cardiac conduction involves the spread of action potentials (AP) across the heart, enabling coordinated contraction of the myocardium. On a cellular level, the transmission of signals between cells is facilitated by low-resistance pathways formed by gap junctions (GJs). Recent experimental studies have sparked discussion on whether GJs play a dominant role in cell communication. Interestingly, research has revealed that GJ knockout mice can still demonstrate signal propagation in the heart, albeit more slowly and discontinuously, indicating the presence of an alternative mechanism for cardiac conduction. Unlike GJ-mediated propagation, ephaptic coupling (EpC) has emerged as a distinct form of electrical transmission, characterized by contactless electrochemical signaling across the narrow intercalated discs (IDs) between cardiomyocytes. Advancements in cardiac research have highlighted the crucial role of EpC in restoring conduction by increasing conduction velocity (CV), reducing conduction block (CB), and terminating reentry arrhythmias, particularly when GJs are impaired. However, most EpC studies are either numerical or experimental, while analytical studies on ephaptic conduction–an equally important aspect of understanding EpC–remain extremely limited. In this paper, we applied asymptotic theory to calculate the CV in the presence of weak EpC. To achieve this, we developed both continuous and discrete models to describe ephaptic conduction along a strand of cells. Ionic dynamics were modeled using the piecewise linear and cubic functions. The resulting system represents a bistable system with weak EpC. We calculated an expression for CV in the presence of weak EpC for both models, and validated our analytical results with numerical simulations. Additionally, we showed that under weak EpC, CV can increase if the distribution of INa is more prominent on the end membrane.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript
- Journal Article:
- https://doi.org/10.1002/adma.202312231
