Hydrogels that are self-assembled by peptides have attracted great interest for biomedical applications. However, the link between chemical structures of peptides and their corresponding hydrogel properties is still unclear. Here, we showed a combinational approach to generate a structurally diverse hydrogel library with more than 2,000 peptides and evaluated their corresponding properties. We used a quantitative structure-property relationship to calculate their chemical features reflecting the topological and physicochemical properties, and applied machine learning to predict the self-assembly behavior. We observed that the stiffness of hydrogels is correlated with the diameter and cross-linking degree of the nanofiber. Importantly, we demonstrated that the hydrogels support cell proliferation in culture, suggesting the biocompatibility of the hydrogel. The combinatorial hydrogel library and the machine learning approach we developed linked the chemical structures with their self-assembly behavior and can accelerate the design of novel peptide structures for biomedical use.self-assembly | dipeptide hydrogels | machine learning H ydrogels that are cross-linked by three-dimensional networks of modified molecules can maintain a large amount of water without dissolving its own chemical structure, which is very similar to natural tissue. As a result of favorable biocompatibility, hydrogels have great potential in biomedical applications such as drug delivery, tissue engineering, sensing, and cell encapsulation (1-7). In the past few years, considerable attention has been directed toward the design of peptide-based hydrogels in particular, not only because of their favorable features such as easy synthesis, decoration, biodegradability, and high compatibility, but also due to their wide applications in the biological and medical fields (8)(9)(10)(11)(12)(13)(14). However, to the best of our knowledge, the prediction and design of peptide-based hydrogels is still challenging, which limits our research choices on peptide-based hydrogels (15,16). Therefore, the design strategy for hydrogels based on peptides is of great significance. Our aim is to reveal the relationship between molecular structure and hydrogel behavior, which can help us to predict and design peptide hydrogels with new chemical structures.There are approaches using molecular dynamics simulation to model the self-assembly behavior of peptides into different types of nanostructures, including nanofibers, which can subsequently form hydrogels (17)(18)(19). However, it is difficult to evaluate the actual prediction accuracy of the molecular dynamics simulation methods because only a few positive peptides were selected and synthesized to test whether they could form a hydrogel. Additionally, the current reported synthetic method on 9fluorenylmethyloxycarbonyl (Fmoc)-peptide is limited to the traditional peptide synthesis method, involving step-by-step protection and deprotection. Since a high-throughput peptide generation method is not available, our first ...

Hospital-acquired infections are a serious threat to the recovery of patients. To prevent such infections, an antibacterial coating is an effective method to eliminate bacterial colonization on healthcare-related surfaces. Herein, we report an antibacterial hydrogel composed of silver-containing polyoxometalate (AgP5W30 POM) and carboxymethyl chitosan (CMC). The silver ion is encapsulated inside the POM cage and demonstrates long-lasting bacteriostasis after repeated exposure to both Gram-positive and Gram-negative bacteria. The chemical structure of chitosan derivatives, as well as the concentration and pH, is studied to tune the mechanical properties of the hydrogel. The hydrogel undergoes a gel–sol transition above the critical temperature and possesses self-healing ability. This hydrogel can be readily coated on the surface of versatile bulk materials, which is especially convenient for porous objects and resists the growth of Staphylococcus aureus, Escherichia coli, and methicillin-resistant S. aureus (MRSA). In summary, we envision that the AgP5W30-CMC hydrogel has great potential to serve as an antibacterial coating to decrease the prevalence of hospital-acquired infections.

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To combat multidrug-resistant bacteria, the cationic amphiphilic polymers as mimics of host defense peptides have been designed and demonstrated potent antibacterial activity. So far, most antibacterial polymers lack the ability...