Development of a manganese complex hyaluronic acid hydrogel encapsulating stimuli-responsive Gambogic acid nanoparticles for targeted Intratumoral delivery.

Gambogic acid is a natural compound with anticancer properties and is effective for many tumors. But its low water solubility and dose-dependent side effects limit its clinical application. This study aims to develop a novel drug delivery system for intratumoral delivery of gambogic acid. In our experimental study, we propose a new method for encapsulating gambogic acid nanoparticles using a manganese composite hyaluronic acid hydrogel as a carrier, designed for targeted drug delivery to tumors. The hydrogel delivery system is synthesized through the coordination of hyaluronic acid-dopamine (HA-DOPA) and manganese ions. The incorporation of manganese ions serves three purposes:1.To form cross-linked hydrogels, thereby improving the mechanical properties of HA-DOPA.2.To monitor the retention of hydrogels in vivo in real-time using magnetic resonance imaging (MRI).3.To activate the body's immune response. The experimental results show that the designed hydrogel has good biosafety, in vivo sustained release effect and imaging tracking ability. In the mouse CT26 model, the hydrogel drug-loaded group can better inhibit tumor growth. Further immunological analysis shows that the drug-loaded hydrogel group can stimulate the body's immune response, thereby better achieving anti-tumor effects. These findings indicate the potential of the developed manganese composite hyaluronic acid hydrogel as an effective and safe platform for intratumoral drug delivery. The amalgamation of biocompatibility, controlled drug release, and imaging prowess positions this system as a promising candidate for tumor treatment.

Bivalent Gadolinium Ions Forming Injectable Hydrogels for Simultaneous In Situ Vaccination Therapy and Imaging of Soft Tissue Sarcoma.

Doxorubicin (DOX) is the classic soft tissue sarcomas (STS) first-line treatment drug, while dose-dependent myelosuppression and cardiotoxicity limit its application in clinic. This research intends to apply DOX, which is also an inducer of immunogenic cell death as a part for "in situ vaccination" and conjointly uses PD-1 inhibitors to enhance antitumor efficacy. In order to achieve the sustained vaccination effect and real-time monitoring of distribution in vivo, the in situ forming and injectable hydrogel platform with the function of visualization is established for local delivery. The hydrogel platform is synthesized by hyaluronic acid-dopamine coordinated with gadolinium ions (Gd2+ ). Gd2+ provides the ability of magnetic resonance imaging, meanwhile further cross-linking the hydrogel network. Experiments show excellent ability of sustained release and imaging tracking for the hydrogel platform. In mouse STS models, the "in situ vaccination" hydrogels show the best effect of inhibiting tumor growth. Further analysis of tumor tissues show that "in situ vaccination" group can increase T cell infiltration, promote M1-type macrophage polarization and block elevated PD-1/PD-L1 pathway caused by DOX. These results are expected to prove the potential for synthesized hydrogels to achieve a universal platform for "in situ vaccination" strategies on STS treatments.