3D printing formulation of probiotic extracellular vesicles for gastrointestinal cancer

Abstract

Despite the well-documented immunomodulatory effects of probiotic-derived extracellular vesicles (EVs) in treating gastrointestinal (GI) related diseases, a significant challenge limiting their therapeutic efficacy arises from their vulnerability to gastric acid degradation when administered orally. Hence, this project aims to address this issue by developing a formulation using 3D bioprinting techniques to encapsulate probiotic EVs, ensuring their preservation in low pH environments and facilitating targeted release in intestinal conditions.

Lactobacilius rhamnosus GG (LGG) was selected due to its well-documented acid resistance and enhanced survival in the intestinal tract. Alginate was chosen as the primary material for the 3D printing formulation. The formulation was optimized with 2 weight % alginate to encapsulate the EVs, maintaining a 1:1 ratio of alginate to EVs. Subsequently, printing parameters were tailored to produce uniform-sized beads.

A preservation study was then conducted to identify the optimal storage environment for preventing degradation of the 3D bioprinted beads. Our findings revealed that deionized (DI) water was the most effective medium for preserving the beads, inhibiting degradation and minimizing EV release prior to storage. Furthermore, the 3D bioprinted alginate-EV beads exhibited potential as a targeted therapeutic delivery system, with increased release observed in an alkaline buffer mimicking bile compared to simulated gastric fluid (SGF).

These results demonstrate the feasibility of the developed formulation for encapsulating LGG EVs, offering promising prospects for their therapeutic application.