3D Bioplotter Research Papers

Displaying all papers by P. Heidarian (5 results)

A self-healing nanocomposite double network bacterial nanocellulose/gelatin hydrogel for three dimensional printing

Carbohydrate Polymers 2023 Volume 313, Article 120879

Extrusion-based three-dimensional (3D) printing of gelatin is important for additive manufactured tissue engineering scaffolds, but gelatin’s thermal instability has remained an ongoing challenge. The gelatin tends to suddenly collapse at mild temperatures, which is a significant limitation for using it at physiological temperature of 37 °C. Hence, fabrication of a thermo-processable gelatin hydrogel adapted for extrusion-based additive manufacturing is still a challenge. To achieve this, a self-healing nanocomposite double-network (ncDN) gelatin hydrogel was fabricated with high thermo-processability, shear-thinning, mechanical strength, self-healing, self-recovery, and biocompatibility. To do this, amino group-rich gelatin was first created by combining gelatin with carboxyl methyl chitosan.…

A 3D printable dynamic nanocellulose/nanochitin self-healing hydrogel and soft strain sensor

Carbohydrate Polymers 2022 Volume 291, Article 119545

Presented here is the synthesis of a 3D printable nano-polysaccharide self-healing hydrogel for flexible strain sensors. Consisting of three distinct yet complementary dynamic bonds, the crosslinked network comprises imine, hydrogen, and catecholato-metal coordination bonds. Self-healing of the hydrogel is demonstrated by macroscopic observation, rheological recovery, and compression measurements. The hydrogel was produced via imine formation of carboxyl methyl chitosan, oxidized cellulose nanofibers, and chitin nanofibers followed by two subsequent crosslinking stages: immersion in tannic acid (TA) solution to create hydrogen bonds, followed by soaking in FeIII solution to form catecholato-metal coordination bonds between TA and FeIII. The metal coordination bonds…

Double dynamic cellulose nanocomposite hydrogels with environmentally adaptive self-healing and pH-tuning properties

Cellulose 2020 Volume 27, Pages 1407–1422

Dynamic hydrogels are prepared by either dynamic covalent bonds or supramolecular chemistry. Herein, we develop a dynamic hydrogel by combining both dynamic covalent bonds and supramolecular chemistry that exhibits environmentally adaptive self-healing and pH-tuning properties. To do so, we prepared a gelatin–nanopolysaccharide mixed hydrogel containing pyrogallol/catechol groups and trivalent metal ions. The as-prepared hydrogels are able to heal damage inflicted on them under acidic (pH 3 and 6), neutral (pH 7), and basic (pH 9) environments. The mechanism of healing at acidic and neutral pHs is dominated by coordination bonds between pyrogallol/catechol groups of tannic acid and ferric ions, whilst…

Fabrication of a conductive composite structure with enhanced stretchability using direct-write 3D printing

Materials Research Express 2019 Volume 6, Number 8, Article 085319

High stretchability and mechanical stability are the key properties of a conductive polymer composite structure. In this work, an anisotropic composite is fabricated by wet 3D printing of epoxy crosslinked chitosan/carbon microtubes. The carbon microtubes were synthesized through a high temperature carbonization of chemically purified cellulose fibres. After the chemical treatment and high temperature carbonization, the removal amorphous substrates from the core of cotton fibres results in the formation of a tubular structure. Here, chitosan which is an abundant natural polymer was used as the composite matrix. It was found that the epoxy crosslinking increases the stretchability of composite filaments.

Wet 3‐D printing of epoxy cross‐linked chitosan/carbon microtube composite

Polymers for Advanced Technologies 2019 Volume 30, Issue 7, Pages 1732-1737

Over the last decays, the use of conductive biopolymer composites has been growing in areas such as biosensors, soft robotics, and wound dressing applications. They are generally soft hydrophilic materials with good elastic recovery and compatible with biological environments. However, their application and removal from the host are still challenging mainly due to poor mechanical strength. This work displays a technique for the fabrication of complex‐shaped conductive structures with improved mechanical strength by wet three‐dimensional (3‐D) printing, which uses a coagulation bath to quickly solidify an epoxy cross‐linked chitosan/carbon microtube composite ink. The fabricated conductive structure demonstrated higher elongation strength…