(M1330-07-42) Development of a Prototype Layer for a Multi-Layer Smart Bandage: Fabrication of Biopolymer-Based Hydrogels with Anti-Inflammatory and Antimicrobial Properties via 3D Bioprinting

Purpose: This study aims to develop hydrogel formulations to prepare a Multilayered bandage for wound healing using the 3D-bioprinting technology. Our main goal is to optimize the 3D bioprinting process and characterize the physico-chemical properties of the hydrogels.

Methods: Required amounts of Medium molecular weight Chitosan and Pluronic® F127 were pre-weighed. Chitosan was dissolved in a 0.5% v/v acetic acid solution and stirred for about 6 hours using a magnetic stirrer (800 rpm) at room temperature until no particles were visually observed. Pluronic® F127 was added, and stirring continued at 4⁰C overnight. The resulting hydrogel was then characterized for rheology using a Modular Compact Rheometer. BioX® 3D-printer was used to print hydrogel formulations (F1-F7). 3D-printing parameters were optimized based on pressure, syringe temperature, printbed temperature, print speed, nozzle diameter, layer height, infill density, and infill pattern. Hydrogel formulations were printed via extrusion-based printing using Computer Aided Design format to print a square-shaped construct. F6 and F7 were selected based on printability and shape fidelity. Genipin was then added to selected formulations to crosslink Chitosan and enhance printability. Selected hydrogels were evaluated for pH using Mettler Toledo pH meter and zeta potential using Malvern zetasizer.

Results: Formulations were prepared using different 0,5% (w/v) of medium molecular weight Chitosan and different rations of Pluronic F127, and Genipin as shown in table 1a. 3D-printing parameters ranged as follows: Layer height(50-100%), print speed (10-20 mm/s), syringe temperature (20-40⁰C), printbed temperature (20-45⁰C), pressure (20-150kPa), infill pattern(Grid, concentric), infill density (25%, 50%), and nozzle diameter (22G-25G). Optimized parameters for printing are shown in table 1b. Selected hydrogel formulation was evaluated for temperature-dependent viscosity, gelation, and storage and loss modulus as shown in figure 1. At 25⁰C, the storage modulus is higher than the loss modulus. Hence, the hydrogel is printable at room temperature. Hydrogel pH measured 4.6 ± 0.1 and zeta potential was 38.6 mV ± 3.02. 3D-printed construct (30x30x1 mm) for multilayered bandage was obtained as shown in figure 2.

Conclusion: Hydrogels containing medium molecular weight chitosan, pluronic F127, and Genipin were formulated and characterized, then successfully printed to form a prototype layer for a multi-layered bandage for wound healing.


Table 1- Hydrogel Formulations and Optimized Printing Parameters


Figure 1- Rheological analysis of Hydrogel Formulation F7


Figure 3- 3D printed hydrogel, A. Freshly printed, and B. 3 days after printing