Longan-inspired chitosan-pectin core-shell hydrogel beads for oral delivery of biodrugs to enhance osteoporosis therapy

Osteoporosis, a common disorder, is characterized by a systemic reduction in bone mass and structural integrity, resulting in brittle bones. Reducing bone loss and enhancing bone density through oral administration of biopharmaceuticals provides significant advantages, including convenience and non-invasiveness for patients. However, challenges such as poor absorption and enzymatic degradation necessitate the development of innovative drug delivery systems. This research introduces a core-shell hydrogel system inspired by the natural architecture of Longan fruit, constructed from pectin and chitosan biopolymers, designed to create biocapsules and sustain the release of biodrugs. In this system, salmon calcitonin (sCT) was encapsulated within mesoporous silica nanoparticles (MSNs) and incorporated into the core of the beads. The synthesis of the core-shell hydrogel beads was carefully regulated by adjusting the immersion time and concentration of the crosslinker. The hydrogel beads demonstrated durability, with the pectin shell effectively preventing rapid degradation in the stomach, while the chitosan layer enhanced adhesion to the intestinal walls, safeguarded sCT, and enabled sustained drug release over an extended period of up to 30 h. Furthermore, biocompatibility tests indicated minimal cytotoxicity and hemolysis. Cellular uptake assays demonstrated that the core-shell beads effectively encapsulated sCT and ensured its prolonged release to CT-26 cells. This study presents a promising platform for oral sCT delivery, offering enhanced efficacy, patient compliance, and a potential replacement for injection-based therapies.