Hyaluronic Acid-Functionalized Alginate Microspheres via Electrospraying for CD44-Mediated Targeted Delivery of Probiotics

Probiotic delivery faces challenges in maintaining bacterial viability and achieving precise targeting of the gastrointestinal tract. In this study, alginate microspheres (ALG MSs) encapsulating <i>Clostridium butyricum</i> (CB) were fabricated using electrospray technology. Hyaluronic acid (HA) was used to modify both the microspheres and the CB surface to enable targeted delivery through the receptor-ligand interaction between HA and CD44. The resulting CB^HA@ALG^HA MSs exhibited an encapsulation efficiency of 69.23 ± 7.30% and a postdigestion survival rate of 94.56 ± 4.87%. HA modification enhanced adhesion to inflamed Caco-2 cells by 2.7- and 2.3-fold for microspheres and CB, respectively. In vivo fluorescence imaging confirmed a 1.7-fold increase in targeted accumulation at CD44-overexpressing inflamed colonic sites. Oral administration of CB^HA@ALG^HA MSs alleviated DSS-induced colitis, elevated short-chain fatty acids, restored barrier integrity, and improved gut microbial balance. This strategy ensures probiotic viability and enables inflammation-targeted colonic delivery for advanced probiotic applications.