Design of functional hydrogel beads based on polysaccharide-encapsulated Ganoderma lucidum spores for stability and targeted gastrointestinal delivery of protein-spore complex.

Oral delivery of protein-based therapeutics and nutraceuticals is often limited by enzymatic degradation and structural instability in gastrointestinal environments, underscoring the need for safe and biocompatible carriers with tailored release profiles. In this study, Ganoderma lucidum spores (GLS) were designed as natural porous scaffolds for loading bovine serum albumin (BSA) to form BSA-GLS complexes, which were subsequently encapsulated within three edible polysaccharide matrices-chitosan, alginate, and pectin-to fabricate dual-layer hydrogel beads with differentiated release behaviors. All beads exhibited millimeter-scale spherical morphology with distinct microarchitectures: compact (chitosan), dense yet porous (alginate), and lamellar (pectin). Distinct release profiles were observed: chitosan beads, characterized by high hardness and cohesiveness, favored gastric-targeted release; alginate beads showed superior mechanical integrity and gradual intestinal release; while pectin beads resisted gastric erosion but enabled rapid, near-complete release under intestinal conditions. All formulations maintained over 90 % protein integrity during fabrication and 60 days of storage at 4 °C, confirming effective stabilization. This study presents the first demonstration of GLS-polysaccharide hybrid beads as a food-grade, dual-layer delivery platform for stabilizing and delivering protein cargos across different gastrointestinal environments.