A sound approach to self-assembly

Controlling the formation of ordered and predictable patterns in dissipative reaction-diffusion processes is challenging. Now, liquid vibrations induced by audible sound have been shown to direct the formation of spatiotemporal patterns in switchable chemical systems and assemblies

Tailor-made functionalized self-assembled peptide (nano)fibers and hydrogels, and methods, uses and kits related thereto

The invention relates to self-assembling peptide (nano)fibers, hydrogels, and methods, uses and intermediate products and kits relating thereto. Provided is a method for providing peptide-based functionally modified (nano)fibers, comprising (i) providing a fiber forming solution comprising pseudopeptide building blocks of the formula A-Peptide-B, wherein: Peptide is a moiety of 1 to 8 amino acid residues having a sequence that is predisposed to form a one-dimensional array, such as β-sheet fibrils; A is an aromatic moiety carrying two reactive thiol groups; and B is a reactive α-nucleophile; (ii) exposing the fiber forming solution to oxidizing conditions to induce supramolecular self-assembly of the pseudopeptide building blocks into peptide-based (nano)fibers; and (iii) contacting said (nano)fibers with at least one biologically relevant functional group of interest comprising reactivity C forming a reactive pair with B to obtain covalently functionally modified nanofibers

Self-Sorting in Dynamic Combinatorial Libraries Leads to the Co-Existence of Foldamers and Self-Replicators

Nature segregates fundamental tasks such as information storage/transmission and catalysis between two different compound classes (e.g. polynucleotides for replication and folded polyamides for catalysis). This division of labor is likely a product of evolution, raising the question of how simpler systems in which replicators and folded macromolecules co-exist may emerge in the transition from chemistry to biology. In synthetic systems, achieving co-existence of replicators and foldamers in a single molecular network remains an unsolved problem. Previous work on dynamic molecular networks has given rise to either self-replicating fibers or well-defined foldamer structures (or completely un-sorted complex systems). We report a system in which two cross-reactive dithiol (nucleobase- and peptide-based) building blocks self-sort into a replicator fiber and foldamer that both emerge spontaneously and co-exist. The self-sorting behavior remains prevalent across different building block ratios as two phases of emergence occur: replicator growth followed by foldamer formation. This is attributed to the autocatalytic formation of the replicator fiber, followed by enrichment of the system in the remaining building block, which is subsequently incorporated into a foldamer

Out-of-equilibrium self-replication allows selection for dynamic kinetic stability in a system of competing replicators

Among the key characteristics of living systems are their ability to self-replicate and the fact that they exist in an open system away from equilibrium. Herein, we show how the outcome of the competition between two self-replicators, differing in size and building block composition, is different depending on whether the experiments are conducted in a closed vial or in an open and out-of-equilibrium replication-destruction regime. In the closed system, the slower replicator eventually prevails over the faster competitor. In a replication-destruction regime, implemented through a flow system, the outcome of the competition is reversed and the faster replicator dominates. The interpretation of the experimental observations is supported by a mass-action-kinetics model. These results represent one of the few experimental manifestations of selection among competing self-replicators based on dynamic kinetic stability and pave the way towards Darwinian evolution of abiotic systems

Antithrombotics in Complex Percutaneous Coronary Interventions: Type and Duration of Treatment

Patients undergoing complex percutaneous coronary intervention (PCI) are at an increased risk of atherothrombotic complications. Although dual antiplatelet therapy is the mainstay of treatment for patients undergoing PCI with stent implantation, deciding its type and duration in complex PCI patients has long been considered a challenge for clinicians. This is because the beneficial effects of prolonged treatment and/or more potent antiplatelet agents’ use in preventing ischemic events are hindered by a concomitant increase in bleeding complications. The aim of this review is to highlight current evidence regarding the optimal antithrombotic therapy regimens used in complex PCI patients, focusing on the evaluation of both safety and efficacy outcomes as well as addressing future perspectives

A Rare Pancreatic Tail Metastasis from Squamous Cell Lung Carcinoma Diagnosed by EUS-FNB and a Small Review of the Literature

Differential diagnosis of pancreatic lesions is really challenging, especially when the patient is diagnosed with primary cancer at another site. In this case report, we managed to histologically confirm pancreatic metastasis from squamous cell lung carcinoma, which is a very rare entity, using endoscopic ultrasound fine needle biopsy

Two Sides of the Same Coin:Emergence of Foldamers and Self-Replicators from Dynamic Combinatorial Libraries

The ability of molecules and systems to make copies of themselves and the ability of molecules to fold into stable, well-defined three-dimensional conformations are of considerable importance in the formation and persistence of life. The question of how, during the emergence of life, oligomerization reactions become selective and channel these reactions toward a small number of specific products remains largely unanswered. Herein, we demonstrate a fully synthetic chemical system where structurally complex foldamers and self-replicating assemblies emerge spontaneously and with high selectivity from pools of oligomers as a result of forming noncovalent interactions. Whether foldamers or replicators form depends on remarkably small differences in building block structures and composition and experimental conditions. We also observed the dynamic transformation of a foldamer into a replicator. These results show that the structural requirements/design criteria for building blocks that lead to foldamers are similar to those that lead to replicators. What determines whether folding or replication takes place is not necessarily the type of noncovalent interaction, but only whether they occur intra- or intermolecularly. This work brings together, for the first time, the fields of replicator and foldamer chemistry

Calcium Channel Blockers and Esophageal Sclerosis: Should We Expect Exacerbation of Interstitial Lung Disease?

Esophageal sclerosis is the most common visceral manifestation of systemic sclerosis, resulting in impaired esophageal clearance and retention of ingested food; in addition, co-existence of lung fibrosis with esophageal scleroderma is not uncommon. Both the progression of generalized connective tissue disorders and the damaging effect of chronic aspiration due to esophageal dysmotility appear to be involved in this procedure of interstitial fibrosis. Nifedipine is a widely prescribed calcium antagonist in a significant percentage of rheumatologic patients suffering from Raynaud syndrome, in order to inhibit peripheral vasospasm. Nevertheless, blocking calcium channels has proven to contribute to exacerbation of gastroesophageal reflux, which consequently can lead to chronic aspiration. We describe the case of severe exacerbation of interstitial lung disease in a 76-year-old female with esophageal sclerosis who was treated with oral nifedipine for Raynaud syndrome