Light Processable Starch Hydrogels

Abstract

Light processable hydrogels were successfully fabricated by utilizing maize starch as raw material. To render light processability, starch was gelatinized and methacrylated by simple reaction with methacrylic anhydride. The methacrylated starch was then evaluated for its photocuring reactivity and 3D printability by digital light processing (DLP). Hydrogels with good mechanical properties and biocompatibility were obtained by direct curing from aqueous solution containing lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) as photo-initiator. The properties of the hydrogels were tunable by simply changing the concentration of starch in water. Photo-rheology showed that the formulations with 10 or 15 wt% starch started curing immediately and reached G’ plateau after only 60 s, while it took 90 s for the 5 wt% formulation. The properties of the photocured hydrogels were further characterized by rheology, compressive tests, and swelling experiments. Increasing the starch content from 10 to 15 wt% increased the compressive stiffness from 13 to 20 kPa. This covers the stiffness of different body tissues giving promise for the use of the hydrogels in tissue engineering applications. Good cell viability with human fibroblast cells was confirmed for all three starch hydrogel formulations indicating no negative effects from the methacrylation or photo-crosslinking reaction. Finally, the light processability of methacrylated starch by digital light processing (DLP) 3D printing directly from aqueous solution was successfully demonstrated. Altogether the results are promising for future application of the hydrogels in tissue engineering and as cell carriers

Sustainable Photopolymers in 3D Printing: A Review on Biobased, Biodegradable, and Recyclable Alternatives

“…[ 38 ] Terpenes, such as linalool monomer and a prepolymer from limonene [ 39 ] and polymyrcene mixed with reactive diluent β‐myrcene, [ 40 ] were used to print porous structures with high ductility following thiol‐ene chemistry. Methacrylated chitosan, [ 41,42 ] starch [ 43 ] and carboxymethyl cellulose [ 44 ] have also been used to print hydrogels, and good biocompatibility has been reported. Moreover, silk fibroin modified with methacrylates was applied in DLP printing to fabricate scaffolds and mimicked organ shapes with excellent biocompatibility.…”

Microwave-assisted methacrylation of chitosan for 3D printable hydrogels in tissue engineering

“…However, chitosan has excellent properties, such as biocompatibility, biodegradability, anti-inflammatory activity, antioxidant effect, and it can diminish foreign body reaction with little or no fibrous encapsulation 27 . Chitosan hydrogels are 3D networks able to absorb and retain liquid and swell, maintaining their mechanical integrity 3,28,29 and have been used in several biomedical applications as drug carriers, absorbable sutures, injectable and 3D-printable biomaterials, due to the hydrophilic nature, biocompatibility and flexibility 30 . Both physical and chemical crosslinking methods are employed to develop chitosan hydrogels.…”

Highly Stretchable Starch Hydrogel Wearable Patch for Electrooculographic Signal Detection and Human–Machine Interaction

“…When tensile strain is applied (%100%), the wavy structure begins to grow evenly throughout the entire surface, enabling sufficient energy dissipation. In addition, the swelling behavior of LRSH patches has been investigated through the conventional gravimetric procedure, [52] as shown in Figure S4, Supporting Information. With NaCl concentration rising from 0 M to saturated, the equilibrium swelling ratio increased from 0.878 to 2.27, indicating hydrogels with higher NaCl content will create higher osmotic pressure, thus uptaking more water when immersed in the aqueous environment.…”