Chitosan-based electroconductive inks without chemical reaction for cost-effective and versatile 3D printing for electromagnetic interference (EMI) shielding and strain-sensing applications.

The burgeoning interest in biopolymer 3D printing arises from its capacity to meticulously engineer tailored, intricate structures, driven by the intrinsic benefits of biopolymers-renewability, chemical functionality, and biosafety. Nevertheless, the accessibility of economical and versatile 3D-printable biopolymer-based inks remains highly constrained. This study introduces an electroconductive ink for direct-ink-writing (DIW) 3D printing, distinguished by its straightforward preparation and commendable printability and material properties.

Freeform Liquid 3D Printing of Soft Functional Components for Soft Robotics.

Freeform liquid three-dimensional printing (FL-3DP) is a promising new additive manufacturing process that uses a yield stress gel as a temporary support, enabling the processing of a broader class of inks into complex geometries, including those with low viscosities or long solidification kinetics that were previously not processable. However, the full exploitation of these advantages for the fabrication of complex multilateral structures has been hindered by difficulties in controlling the interfaces between inks and supports. In this work, an in-depth study of the rheological properties and interfacial stabilities between a nanoclay-modified support and silicone-based inks enabled a better understanding of the impact printing parameters have on the extruded filament morphology, and thus on printing resolutions.

Biomimetic Janus chitin nanofiber membrane for potential guided bone regeneration application.

Biopolymer-based membranes are at the forefront of the guided bone regeneration (GBR) in orthopaedics and dentistry, which prevent fast-growing soft tissue migration to the defected alveolar ridge or implants and allow the bone regeneration. In this study, we fabricated a novel Janus -two-faced, GBR membrane composed of a chitin nanofiber face for bone regeneration and a cell membrane mimetic antifouling 2-Methacryloyloxyethyl phosphorylcholine (MPC) polymeric face for suppressing the migration of the soft tissue. In vitro cell study showed a higher cell proliferation rate of osteoblast cells on the chitin nanofiber surface and a lower proliferation rate of fibroblasts cells on the antifouling MPC side.

Circular manufacturing of chitinous bio-composites via bioconversion of urban refuse.

Bioinspired manufacturing, in the sense of replicating the way nature fabricates, may hold great potential for supporting a socioeconomic transformation towards a sustainable society. Use of unmodified ubiquitous biological components suggests for a fundamentally sustainable manufacturing paradigm where materials are produced, transformed into products and degraded in closed regional systems with limited requirements for transport. However, adoption is currently limited by the fact that despite their ubiquitous nature, these biopolymers are predominantly harvested as industrial and agricultural products.

Stimuli-responsive injectable cellulose thixogel for cell encapsulation.

Herein, we present the synthesis of surface-oxidized cellulose nanofiber (CNF) hydrogel and characterization with various physicochemical analyses and spectroscopic tools as well as its suitability for cellular encapsulation and delivery. The structure-property relationship as shear thinning, thixotropy, creep-recovery and stimuli responsiveness are explored. The CNF hydrogel is capable to inject possessing shear thinning behavior at shear rate (~10 s) range in the normal injecting process.

Tunichrome-inspired pyrogallol functionalized chitosan for tissue adhesion and hemostasis.

The nature-inspired fabrication of tissue adhesive and hemostatic hydrogels holds great potential for restoring damaged internal tissue in regenerative medicine. However, feeble adhesion, multifaceted systems, prohibitive costs, and toxicity impede their applications in the medical field. In order to solve this problem, we fabricated chitosan-based wet tissue adhesive with hemostatic functions inspired by the self-healing mechanism of the tunicate.

Large-scale additive manufacturing with bioinspired cellulosic materials.

Cellulose is the most abundant and broadly distributed organic compound and industrial by-product on Earth. However, despite decades of extensive research, the bottom-up use of cellulose to fabricate 3D objects is still plagued with problems that restrict its practical applications: derivatives with vast polluting effects, use in combination with plastics, lack of scalability and high production cost. Here we demonstrate the general use of cellulose to manufacture large 3D objects.

Mussel-Inspired Anisotropic Nanocellulose and Silver Nanoparticle Composite with Improved Mechanical Properties, Electrical Conductivity and Antibacterial Activity.

Materials for wearable devices, tissue engineering and bio-sensing applications require both antibacterial activity to prevent bacterial infection and biofilm formation, and electrical conductivity to electric signals inside and outside of the human body. Recently, cellulose nanofibers have been utilized for various applications but cellulose itself has neither antibacterial activity nor conductivity. Here, an antibacterial and electrically conductive composite was formed by generating catechol mediated silver nanoparticles (AgNPs) on the surface of cellulose nanofibers.

Tunicate-Inspired Gallic Acid/Metal Ion Complex for Instant and Efficient Treatment of Dentin Hypersensitivity.

Dentin hypersensitivity is sharp and unpleasant pains caused by exposed dentinal tubules when enamel outside of the tooth wears away. The occlusion of dentinal tubules via in situ remineralization of hydroxyapatite is the best method to alleviate the symptoms caused by dentin hypersensitivity. Commercially available dental desensitizers are generally effective only on a specific area and are relatively toxic, and their performance usually depends on the skill of the clinician.

Chemical studies on the polysaccharides of Salicornia brachiata.

A group of 12 polysaccharide extracts were prepared from the tips, stem and roots of an Indian halophyte Salicornia brachiata Roxb. obtained by sequential extractions with cold water (CW), hot water (HW), aqueous ammonium oxalate (OX) and aqueous sodium hydroxide (ALK) solutions. Monosaccharide composition analysis revealed that all the polysaccharide extract samples consisted primarily of rhamnose, arabinose, mannose, galactose, glucose, whereas ribose and xylose were present only in some of the extracts.

Facile synthesis of a new fluorogenic metal scavenging interpolymeric diamide based on cellulose and alginic acids.

A microwave assisted synthesis of a water soluble fluorogenic interpolymeric diamide has been described involving alginic acid and polyglucuronic acid (PGA) amide of ethylenediamine (EDA), through a monoamide of PGA and EDA, in good yields (>80wt% in each step). PGA was prepared by TEMPO (2,2,6,6-tetramethyl piperidine-1-oxyl radical) mediated oxidation of cellulose of the halophytic plant Salicornia brachiata. The amides were characterized by spectral analyses.

Cellulose contents of some abundant Indian seaweed species.

Crude cellulose as well as alpha- and beta-celluloses were estimated in thirty-four seaweed species of fifteen orders of Chlorophyta, Phaeophyta and Rhodophyta of Indian waters. The greatest yields of crude cellulose and a-cellulose were obtained from Chaetomorpha aerea (approx. 20.

Cellulose of Salicornia brachiata.

Cellulose was extracted from the roots, stems and stem tips of Salicornia brachiata Roxb. Each crude cellulose sample obtained was fractionated into alpha- and beta-celluloses. The yields of crude cellulose from the stems and stem tips were greatest and lowest, respectively, while the yields of alpha- and beta-celluloses were in the order, roots > stems > stem tips.

Profiling of cellulose content in Indian seaweed species.

Cellulose contents were estimated in 12 seaweed samples belonging to different families e.g. red, brown and green, growing in Indian waters.