Corrosion of metallic materials can have a detrimental impact on their performance, leading to a shortened service life of engineering equipment and posing risks to both people and the environment. This paper presents a novel epoxy resin (EP)-based composite coating (PFANI-GO/EP) that offers triple corrosion protection functions: barrier, passivation, and corrosion inhibition. Perfluorooctanoic acid-doped polyaniline modified graphene oxide (PFANI-GO) demonstrates superhydrophobicity, effectively enhancing the coating's barrier ability against corrosive substances. The combination of PANI and perfluorooctanoic acid (PFOA) in composite materials aids in the formation of a passivation film and hydrophobic layer, which prevent metal corrosion. After a 15-day immersion in brine, the PFANI-GO/EP coating demonstrates the highest impedance modulus of 1 x 109 Omega & sdot;cm2 at 0.01 Hz, compared to pure EP coating, GO/EP coating, and PFANI/EP coating. Therefore, due to its corrosion resistance and prolonged corrosion aging time, PFANI-GO/EP coating shows promising potential for mitigating metal corrosion.
Multifunctional wound dressings are promising medical materials for various applications. Among them, dressings with antimicrobial activity, high biosafety, and real-time monitoring have attracted considerable research interest. Herein, a biodegradable hemostatic sponge comprising a chitosan skeleton and polyelectrolyte-surfactant complex (CS-PEC) was developed as a versatile wound dressing for wound pH monitoring and inhibition of bacterial infection. CS-PEC sponge with high porosity exhibited satisfactory fluid absorption capacity and biocompatibility, along with antibacterial properties against E. coli and S. aureus. In vivo experiments in rat liver trauma model revealed that wounds treated with the CS-PEC sponge recorded less blood loss (97.1 mg) and shorter hemostasis time (27.2 s) than those treated with commercial gelatin sponge (309.1 mg and 163.5 s, respectively). Furthermore, PECs based on unconventional luminescent molecules (L-C16-Hyp) were used as pH fluorescent indicators, which endowed the sponge with fluorescence-responsive behavior to wound pH changes in the range of 5.0-8.5. Visual images can be captured using a smartphone and converted to RGB color mode values for on-site assessment of wound status. This study sheds light on the design and application of unconventional luminescent materials in wound dressing and provides a smart and effective solution for wound management.
Herein, a novel bioinspired radial porous zinc-based metal-organic framework (Zn-MOF) doped sodium alginate/chitosan derivatives/pullulan-based SA/PSCS/Pul/Zn-MOF (SPCP/Zn) composites sponge with excellent antioxidant and antibacterial properties was fabricated by the ice-templating method. Boric acid (BA) and Ca2+, which were respectively used as hydrogen- and ionic- bonding cross-linkers, provided strong mechanical properties for sponge matrix composed of SA, PSCS, and Pul. The obtained SPCP/Zn sponge exhibited uniform porous morphology, proper hydrophilicity, and admirable biocompatibility. In addition, the SPCP/Zn sponge achieved a sustained release of Zn2+ and gallic acid, which displayed powerful antibacterial and antioxidant activities. Importantly, the SPCP/Zn sponge exhibited shorter rapid hemostasis (20.4 ± 2.9 s) and lower blood loss (19.8 ± 4.3 mg). The SPCP/Zn sponge also showed faster wound closure ratio for the rat full-thickness skin defect model. It was revealed that SPCP/Zn sponge could significantly accelerate and enhance wound healing through downregulating inflammatory cytokines (TNF-α, IL-6) and increasing the expression of growth factors (VEGF). Due to its excellent properties, the SPCP/Zn sponge may have promising potential in wound healing applications.
Irregular hemorrhagic traumas always threaten the health of patients due to uncontrollable bleeding and wound infections. The traditional hemostatic materials show dissatisfactory hemostatic efficiency and antibacterial activity in solving these potential bleeding dangers. Herein, we proposed a kind of composites based on flexible wood membrane (FWM) loaded with chitosan/alginate derivative for accelerating rapid hemostasis and preventing infection. FWM was removed part of hemicellulose and lignin by using NaOH/Na2SO3 mixture to obtain excellent flexibility while retaining the original porous structure, followed by loading silver nanoparticles on the FWM surface to prepare AgNPs-FWM as an antibacterial bio-carrier. Then, AgNPs-FWM was coated with polyoxyethylene stearate-modified chitosan and multi-aldehyde sodium alginate to fabricate the composites of chitosan/alginate/AgNPs-FWM (CSA/AgNPs-FWM) using in-situ Schiff base reaction. Furthermore, in vitro and in vivo experiments showed that the CSA/AgNPs-FWM composites exhibited lower BCI value (2.6 ± 1.3 %), more rapid hemostasis (26 s) and lower blood loss (67.8 mg) than that of the traditional materials. The possible mechanism for the hemostasis process was not only the high blood absorption capacity, but also the synergistic interaction between hydrophobic alkane chains, amino groups, aldehydes, hydroxyl groups and blood cells. Moreover, CSA/AgNPs-FWM showed exceptional superiorities in mechanical properties and antibacterial activity, which endowed composites high potential in hemostasis application for irregular external wound.