Developing safe and efficient bioformulations using approved materials and ingenious designs can accelerate the clinical translation process.

Scientists have developed a new therapeutic tumor vaccine based on self-healing polylactic acid microcapsules, which can efficiently activate the immune system and inhibit tumor development.

This research was published in Science Advances. Therapeutic cancer vaccines that harness the immune system to reject cancer cells have shown great promise for tumor treatment.

The senior author said that an unfavorable immunization microenvironment, along with a complicated preparation process and the need for frequent vaccinations significantly compromised their performance. "Therefore, we designed a novel microcapsule-based formulation for high-performance cancer vaccinations," said the author. This study represents the first time researchers used self-healing microcapsules with post-encapsulation, multiple loading, and efficient modulation of immunization microenvironments in a tumor vaccine. The special self-healing feature provides a mild and efficient paradigm for antigen microencapsulation. After vaccination, these microcapsules create a favorable immunization microenvironment in situ, wherein antigen release kinetics, recruited cell behavior and acid surrounding environment work in a synergetic manner. Owing to synergetic effects, the vaccine succeeds in increasing antigen utilization, improving antigen presentation and activating antigen presenting cells. "As a result, effective T cell response, potent tumor inhibition, anti-metastatic effects and prevention of postsurgical recurrence are achieved with various types of antigens in different tumor models," said the senior author.

Moreover, the researchers verified the availability of the novel vaccine platform used in the neoantigen vaccine, which conforms to precision medicine, said the senior author. Due to the simple post-encapsulation process, the clinicians were able to prepare the neoantigen formulation by themselves at any time.