Due to the combination of surface micro/nanostructure and surface chemical modification,
superwettable interfacial materials have exhibited remarkable functions in muti-fields,
such as anti-fouling, sensor detection, materials manufacture and medical treatment.
The most advantageous strategy to construct and prepare superwetting materials and
expand their probable applications is deeply investigating the potential mechanisms
of superwetting biological organisms. During the last 2 decades, superwetting biological
organisms with superhydrophobicity, superhydrophilicity, directional liquid-transportation,
and multifunctional composite surfaces integrating superwettability with other physicochemical
properties have brought great enlightenment to the development of superwettable materials.
With further research of more unique biological phenomena, more practical superwetting
materials will be utilized for a wider range of applications in the near future.
The primary task of this Research Topic is to compile high-level researches on bioinspired
superwettable materials for the solution of actual scientific problems. In this Research
Topic, we present ten original articles and seven review articles, aiming to highlight
the recent progress of bioinspired superwetting materials in the fields as diverse
as controlled preparation of functional materials, anti-fouling, biosensing and biomedicine,
etc.
The deposition of unwanted objects (e.g., ice, wax and bacteria) has been caused significant
Research Topic in both daily life and industrial production. As a result, there has
been an increased interest in the development of superwetting interfacial materials
that offer efficient and sustainable resistance to deposition. Zhang et al. prepared
a cheap superwetting micro/nanostructured surfaces with excellent anti-icing properties
and promising applications scenarios in low-temperature environments. The surface
was fabricated by the combination of deep reactive ion etching, glancing angle deposition,
and fluorocarbon deposition. Based on classical heterogeneous nucleation theory, Li
et al. roughened and fluorization-modified an Al substrate for preparing the superhydrophobic
surfaces. The water vapor condensation experiment finally confirmed that only superhydrophobic
surfaces with coral-like micro/nano-structures showed excellent anti-condensation
properties, the droplets appear slowly and the number of droplets is rare. Due to
a higher nuclear barrier caused by the smaller nanostructure, most of the superhydrophobic
materials areas remained dry. This research offers a new avenue for the practical
application of advanced superhydrophobic materials in anti-solid and anti-liquid fouling.
Biofilms, which are the primary cause of most oral diseases, originate from the attachment
of salivary proteins and pioneer bacteria. Natural antifouling surfaces inspire new
antibacterial strategies. Zhang et al. summarized the mechanisms and fabrication strategies
of bio-inspired superwetting materials to prevent the adhesion of bacteria, and highlighted
their applications in dentistry. These novel strategies provide a solid foundation
for oral antimicrobial application and improving the efficacy of anti-bacteria. The
reason why bio-inspired superhydrophobic preparation means has received intense attention
in recent years is that it has been widely applied in anti-fouling, liquid-liquid
separation, and other applications. Ge-Zhang et al. expounded the basic principle
of superhydrophobic surface through different superhydrophobic models, summarized
the structural features of biological superhydrophobic surfaces (e.g., lotus leaves),
and detailly introduced the characteristics differences and applications of various
surfaces. Finally, the challenges and future development directions of bionic superhydrophobic
surfaces were discussed. However, the poor durability of bio inspired superhydrophobic
materials limits their practical application. In addition to elucidating five typical
superhydrophobic models, Luo et al. summarized the improvement of superhydrophobic
surfaces in terms of wear resistance and chemical corrosion resistance, and discussed
the testing measure of durability such as tape-peeling methods and electchemical corrosion.
They also demonstrated the application of stable superhydrophobic interfacial materials
in anti-fouling, mixture separation, membrane distillation, and electrochemical process.
With the advancement in the field of nanotechnology, nanomaterials or bionic nano
platforms of different scales have been applied in related fields such as reverse
electrodialysis, clinical analysis, etc. These materials have selective separation
and recognition functions. Inspired by the electric eel, ions can be selectively transferred
by their unique ion channels for generating electricity, Yao et al., performed a composite
membrane based on metal-organic framework, thereby achieving high-effective power
production from salinity difference of sea water and river water. The composite membrane
has a dense structure and exhibits long-term stability in saline. This study provides
a guiding path for producing the high-effective salinity-gradient power generation
systems based on selective transportation of anion. To effectively separate phosphopeptides
and glycopeptides, Shang et al. constructed silica microspheres modified with polyhistidine.
The combination of hydrophilic and hydrogen bonding interactions endow silica microspheres
with high selectivity and coverage, benefiting for the Research Topic of phosphopeptides
and glycopeptides at the same time, . Furthermore, this strategy allows sequential
elution of phosphopeptides and glycopeptides, showing significant potential in co-analysis
of protein in clinical medicine. For the patients with chronic kidney disease, cardiac
surgery-associated acute kidney injury (CSA-AKI) may increase the mortality rates
of the disease. Bai et al. used Gemini C18 column and high-resolution mass spectrometry
to analysis the proteomic of urine samples from six CSA-AKI patients, aimed to investigate
the possible correlation between changes in urine proteomics and CSA-AKI. The Gemini
C18 silica microspheres can be enhanced the protein recognition rate to achieve highly
precious resources for the urinary differential expressed proteins of AKI. This analysis
provides indispensable foundation about urinary proteome biomarkers and valuable resources
for deeper study of AKI. Additionally, Wu et al. concluded the various bio-inspired
nanoparticles (e.g., metallic nanoparticles, polymeric nanoparticles and nanovesicles)
in biomedical fields and discussed the progress of bioinspired nanotechnology in biomedicine.
Then, they highlighted the importance of fabricating nanoparticles through the bioinspired
route. Finally, the preparation of new nanoparticles and their applications in the
field of biomedicine are prospected.
Superwettable surfaces have also been extensively studied for use in fabricating sensors
(e.g., electrochemical immunosensor and non-enzymatic sensors) in medical field. As
one of the neurodegenerative disease, Alzheimer’s disease (AD) is caused by the injury
of brain neurons, which severely affect human normal life and health. Based on the
superwetting microdroplet array, Huang et al. reported an sensing platform by electrochemical
way for detecting various AD biological markers in blood. In comparison, this superwetting
sensor has excellent properties such as large specific surface area, excellent conductivity
and prominent biocompatibility. In addition to health detection, Chen et al. developed
a non-enzyme sensor with the liquid-solid-air triphase interfacial electrode for electrochemical
applications. The sensor collaboratively utilizes the property of electrocatalytic
glucose oxidation to promote the formation of local alkalinity production. The high
local pH value is obtained through the oxidation reaction at the three-phase interface,
thus realizing the electrochemical detection of glucose at neutral solution. For acquiring
deep insight into the biosensors, Yang et al. clearly introduced the sensing methods
of superwetting biosensors for disease detection by biomarkers, which mainly introduces
disease analysis by fluorescence analysis, electrochemistry display, surface enhancement
Raman scattering assay and visional means. The author further systematically introduces
the applications of super-wettable biosensors in the field of biomarkers, and finally
gives suggestions on the future challenges and development of sensors.
As one of the superwettable materials, interestingly, superwetting materials can enhance
the ability of cartilage regeneration. Inspired by the mussel-adhesive phenomenon,
Chi et al. proposed a simple preparation method for osteoconductive and osteoinductive
nanomaterials utilizing material extrusion techniques and surface modification strategies.
By adding polydopamine and hydroxyapatite nanoparticles on the surface of the composite
material, the 3D printed porous scaffold with enhanced osteogenesis was prepared.
The physical and chemical properties of the scaffold such as surface wettability,
roughness, mechanical performance, and biodegradability was studied to demonstrate
the enhanced osteogenesis ability. The superwetting material will inevitably endure
the impact of the bone, Liu et al. investigated the impact resistance and energy dissipation
of multilayer bioinspired composites based on the fiber periodic helical structure
of fibers. Under the same material component and property parameters, adjusting the
fiber spiral angle of the fiber can effectively improve the stress concentration of
the bioinspired materials caused by external impact. In conclusion, the mineralized
collagen fibers based on the periodic spiral structure in osteons can effectively
improve the impact resistance property of cortical bone. The research results have
guiding significance for the design and preparation of high performance biomimetic
osteogenic superwetting materials. Inducing cartilage reproduction can cure temporomandibular
disorders with biomaterials. However, the wettability of bone-filled biomaterials
was not satisfactory. For addressing this problem, Yang et al. placed mesenchymal
stem cells with wetting properties on the surface of TGF-β-loaded gelatin methacryl
microspheres, resulting in active wetting of biomaterials. Modified gelatin-MSCs microspheres
can more effectively localize bone defect repair sites, expediting the healing of
temporomandibular joint defect area caused by releasing cytokines at specific sites.
This method provides a new strategy for the development of cartilage regeneration
materials through the addition of infiltrating factors. Therefore, superwetting materials
will play a great role in bioengineering and medical remediation. As one of the bioinspired
superhydrophilic materials, hydrogels have excellent properties such as biocompatibility,
biodegradability and strong crosslinking. The above excellent physical and chemical
properties will make hydrogels promising to be a new delivery platform and unconventional
therapy for repairing endometrial damage. Many works on bioinspired-hydrogels for
subcavity endometrial repair was discussed. For example, As the post-operative physical
barrier and therapeutic delivery platform, Dong et al. discussed recent developments
in hydrogel delivery platforms for endometrial repair. In addition, the development
status, application limitations and future development of hydrogels are discussed
in detail. Liquid-infused surfaces (LIS) also have unique prospects in the fields
of biological engineering, medical equipment, and biosensor. LIS also play an important
role in the fields of bioengineering, medical devices and biosensing. Yang et al.
focused on the influence of liquid layers on the properties of medical materials.
At the same time, the development trend of information system in the future is forecasted.
Overall, this Research Topic cover several cutting-edge fields in bio-inspired materials
with superwettability, such as anti-adhesive materials, sensing detection systems,
life medical treatments, etc., which help readers understand the application progress
of bio-inspired materials with superwettability. Despite the encouraging results mentioned
above, more research is still needed to gain a deeper understanding of the mechanisms
for applications and to develop more superwetting materials that can be applied more
quickly.