Molecular self-assembly is a key direction for the fabrication of advanced materials. Yet, the physical properties of the formed assemblies are limited by the inherent characteristics of the specific building blocks. Here, we have applied a co-assembly approach to synergistically modulate the mechanical properties of peptide hydrogels, thereby forming extremely stable and rigid hydrogels.

Hyaluronic acid (HA), a major component of the extracellular matrix, is an attractive material for various medical applications. Yet, its low mechanical rigidity and fast in vivo degradation hinder its utilization. Here, we demonstrate the reinforcement of HA by its integration with a low-molecular-weight peptide hydrogelator to produce a composite hydrogel. The formulation of HA with the fluorenylmethoxycarbonyl diphenylalanine (FmocFF) peptide, one of the most studied self-assembling hydrogel-forming building blocks, showing notable mechanical properties, resulted in the formation of stable, homogeneous hydrogels. Electron microscopy analysis demonstrated a uniform distribution of the two matrices in the composite forms. The composite hydrogels showed improved mechanical properties and stability to enzymatic degradation while maintaining their biocompatibility. Moreover, the storage modulus of the FmocFF/HA composite hydrogels reached up to 25 kPa. The composite hydrogels allowed sustained release of curcumin, a hydrophobic polyphenol showing antioxidant, anti-inflammatory, and antitumor activities. Importantly, the rate of curcumin release was modulated as a function of the concentration of the FmocFF peptide within the hydrogel matrix. This work provides a new approach for conferring mechanical rigidity and stability to HA without the need of cross-linking, thus potentially facilitating its utilization in different clinical applications, such as sustained drug release.

Low‐molecular‐weight self‐assembled peptides may serve as promising hydrogelators for drug delivery applications by changing their structural network in response to external stimuli. Herein, inspired by the well‐studied low‐molecular‐weight peptide hydrogelator, fluorenyl‐methoxycarbonyl‐diphenylalanine (Fmoc‐FF), a novel peptide is designed and synthesized to include an ultraviolet (UV)‐sensitive phototrigger. Similar to Fmoc‐FF, 6‐nitroveratryloxycarbonyl‐diphenylalanine (Nvoc‐FF) self‐assembles to form a 3D, self‐supporting, nanofibrous hydrogel. The Nvoc‐FF hydrogel exhibits good mechanical properties with a storage modulus of 40 kPa. UV irradiation of the Nvoc‐FF hydrogel encapsulating insulin‐fluorescein isothiocyanate (insulin‐FITC) results in the cleavage of Nvoc‐FF peptide to produce unmasked FF, thereby facilitating the degradation of the hydrogel and the release of insulin‐FITC. This release is in linear correlation to the irradiation time. In the present study, a first insight into this rigid, fibrous, light‐responsive hydrogel is provided, allowing the fabrication of a novel drug delivery system for controlled release of large molecules.

Ridge preservation using bovine derived xenograft might reduce sinus pneumatization along with minimizing crestal bone resorption.

Based on this study, inadequate vestibular depth around dental implants may be associated with increased peri-implant bone loss and mucosal recession. Further prospective and intervention studies will be required to fully understand this phenomenon.

In cases of implant failure, implantation of foreign bodies may play a role with subsequent development of I-PG and I-PGCG-like lesions. Clinicians should be aware of this risk so they can implement measures to minimize adverse implant outcomes.

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In this paper, we report the in situ growth of FF nanotubes examined via liquid-cell transmission electron microscopy (LCTEM). This direct, high spatial, and temporal resolution imaging approach allowed us to observe the growth of peptide-based nanofibrillar structures through directional elongation. Furthermore, the radial growth profile of FF nanotubes through the addition of monomers perpendicular to the tube axis has been observed in real-time with sufficient resolution to directly observe the increase in diameter. Our study demonstrates that the kinetics, dynamics, structure formation, and assembly mechanism of these supramolecular assemblies can be directly monitored using LCTEM. The performance of the peptides and the assemblies they form can be verified and evaluated using post-mortem techniques including time-of-flight secondary ion mass spectrometry (ToF-SIMS).