Given their durability and long‐term stability, self‐healable hydrogels have, in the past few years, emerged as promising replacements for the many brittle hydrogels currently being used in preclinical or clinical trials. To this end, the incompatibility between hydrogel toughness and rapid self‐healing remains unaddressed, and therefore most of the self‐healable hydrogels still face serious challenges within the dynamic and mechanically demanding environment of human organs/tissues. Furthermore, depending on the target tissue, the self‐healing hydrogels must comply with a wide range of properties including electrical, biological, and mechanical. Notably, the incorporation of nanomaterials into double‐network hydrogels is showing great promise as a feasible way to generate self‐healable hydrogels with the above‐mentioned attributes. Here, the recent progress in the development of multifunctional and self‐healable hydrogels for various tissue engineering applications is discussed in detail. Their potential applications within the rapidly expanding areas of bioelectronic hydrogels, cyborganics, and soft robotics are further highlighted.

Biomaterials capable of transmitting signals over longer distances than those in rigid electronics can open new opportunities for humanity by mimicking the way tissues propagate information. For seamless mirroring of the human body, they also have to display conformability to its curvilinear architecture, as well as, reproducing native‐like mechanical and electrical properties combined with the ability to self‐heal on demand like native organs and tissues. Along these lines, a multifunctional composite is developed by mixing silk fibroin and reduced graphene oxide. The material is coined “CareGum” and capitalizes on a phenolic glue to facilitate sacrificial and hierarchical hydrogen bonds. The hierarchal bonding scheme gives rise to high mechanical toughness, record‐breaking elongation capacity of ≈25 000%, excellent conformability to arbitrary and complex surfaces, 3D printability, a tenfold increase in electrical conductivity, and a fourfold increase in Young's modulus compared to its pristine counterpart. By taking advantage of these unique properties, a durable and self‐healing bionic glove is developed for hand gesture sensing and sign translation. Indeed, CareGum is a new advanced material with promising applications in fields like cyborganics, bionics, soft robotics, human–machine interfaces, 3D‐printed electronics, and flexible bioelectronics.

Despite the promise of hydrogel-based stem cell therapies in orthopedics, a significant need still exists for the development of injectable microenvironments capable of utilizing the  regenerative potential of donor cells. Indeed, the quest for biomaterials that can direct stem cells into bone without the need of external factors has been the "Holy Grail" in orthopedic stem cell therapy for decades. To address this challenge, we have utilized a combinatorial approach to screen over 63 nanoengineered hydrogels made from alginate, hyaluronic acid, and two-dimensional nanoclays. Out of these combinations, we have identified a biomaterial that can promote osteogenesis in the absence of well-established differentiation factors such as bone morphogenetic protein 2 (BMP2) or dexamethasone. Notably, in our "hit" formulations we observed a 36-fold increase in alkaline phosphate (ALP) activity and a 11-fold increase in the formation of mineralized matrix, compared to the control hydrogel. This induced osteogenesis was further supported by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and energy-dispersive X-ray spectroscopy. Additionally, the Montmorillonite-reinforced hydrogels exhibited high osteointegration as evident from the relatively stronger adhesion to the bone explants as compared to the control. Overall, our results demonstrate the capability of combinatorial and nanoengineered biomaterials to induce bone regeneration through osteoinduction of stem cells in a natural and differentiation-factor-free environment.

This study aimed to develop a drug carrier based on amine-functionalized mesoporous silica nanoparticles (AAS-MSNPs) for a poorly water-soluble drug, curcumin (CUR), and to study its effects on α-synuclein (α-Syn) fibrillation and cytotoxicity. Here, we show that AAS-MSNPs possess high values of loading efficiency and capacity (33.5% and 0.45 mg drug/mg MSNPs, respectively) for CUR. It is also revealed that α-Syn species interact strongly with the CUR-loaded AAS-MSNPs, leading to a significant inhibition of the fibrillation process. Furthermore, these samples reduce the toxic effects of CUR. However, drug-loaded AAS-MSNPs do not affect the cytotoxic properties of the formed fibrils considerably. In addition, CUR loaded onto AAS-MSNPs shows enhanced stability in comparison with that of the free drug. These remarkable properties introduce AAS-MSNPs as a promising tool for the formulation of poorly water-soluble drugs such as CUR.