This review provides a comprehensive survey of the structural characteristics of crystal networks of silk soft fibrous materials in correlation with the macroscopic properties/performance and the network formation mechanisms. The correlation between the hierarchical mesoscopic structures and the mechanical properties of silk soft fibrous materials including silk fibroin hydrogels and naturally spun silk fibers are addressed based on the hierarchical crystal network models. Namely, two types of hierarchical networks are identified: the weak nanofibril-nanofibril interaction case (i.e., silk fibroin hydrogels), and the strong nanofibril-nanofibril interaction case (i.e., silk fibers). The macroscopic properties, i.e., the rheological/mechanical properties, can be controlled in terms of tuning different levels of hierarchical network structures by ultrasonication-induced gelation, introducing the initial nucleation centers, etc. Such controls take effect by different mesoscale assembly pathways, which are found to occur via different routes of the nucleation and growth processes. Furthermore, the hierarchical network model of soft fibrous materials can be applied to explain the superior mechanical properties and the unique strain-hardening behaviors of spider silk fibers within the framework of hierarchical breaking mechanism. Obviously, a knowledge of crystal networks will allow the prediction of the performance and engineering strategy of silk fibrous materials in generals.

Skin damages are defined as one of most common lesions people suffer from, some of wounds are notoriously difficult to eradicate such as chronic wounds and deep burns. Existing wound therapies have been proved to be inadequate and far from satisfactory. The cutting-edge nanotechnology offers an unprecedented opportunity to revolutionize and invent new therapies or boost the effectiveness of current medical treatments. In particular, the nano-drug delivery systems anchor bioactive molecules to applied area, sustain the drug release and explicitly enhance the therapeutic efficacies of drugs, thus making a fine figure in field relevant to skin regeneration. This review summarized and discussed the current nano-drug delivery systems holding pivotal potential for wound healing and skin regeneration, with a special emphasis on liposomes, polymeric nanoparticles, inorganic nanoparticles, lipid nanoparticles, nanofibrous structures and nanohydrogel.

Androgenetic alopecia (AGA) is highly prevalent in current society but lacks effective treatments. The dysregulation of the hair follicle niche induced by excessive reactive oxygen species (ROS) and insufficient vascularization in the perifollicular microenvironment is the leading cause of AGA. Herein, we designed a ceria nanozyme (CeNZ)-integrated microneedles patch (Ce-MNs) that can alleviate oxidative stress and promote angiogenesis simultaneously to reshape the perifollicular microenvironment for AGA treatment. On the basis of the excellent mechanical strength of Ce-MNs, the encapsulated CeNZs with catalase-and superoxide-mimic activities can be efficiently delivered into skin to scavenge excessive ROS. Moreover, the mechanical stimulation induced by the administration of MNs can remodel the microvasculature in the balding region. Compared with minoxidil, a widely used clinical drug for AGA treatment, Ce-MNs exhibited accelerated hair regeneration in the AGA mouse model at a lower administration frequency without inducing significant skin damage. Consequently, such a safe and perifollicular microenvironment-shaping MNs patch shows great potential for clinical AGA treatment.

The ability to pattern natural polymers at different scales is extremely important for many research areas, such as cell culture, regenerative medicine, bioelectronics, tissue engineering, degradable implants, and photonics. For the first time, the use of wool keratin (WK) as a structural biomaterial for fabricating precise protein microarchitectures is presented. Through straightforward biochemical processes, modified WK proteins become intrinsically photoreactive without significant changes in protein structure or function. Under light irradiation, intermolecular chemical crosslinking between WK molecules can be successfully initiated by using commercially available photoinitiators. As a result, high‐performance WK patterning on the micrometer scale (µm) can be achieved through a combination of water‐based photolithography techniques. By simply mixing with nanoparticles, enzymes, and other dopants, various “functional WK resists” can be generated. In addition, without the addition of any cell‐adhesive ligands, these patterned protein microstructures are demonstrated as bio‐friendly cellular substrates for the spatial guidance of cells on their surface. Furthermore, periodic microfabricated WK structures in complex patterns that display typical iridescent behavior can be designed and formed over macroscale areas (cm).

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