7.2.3.1　Polymer scaffolds

As special materials for immunotherapy，polymer scaffolds can provide the structure and volume of continuous interaction with the surrounding microenvironment，which can overcome the problem of poor immunogenicity and further improve the efficiency of immunotherapy，while reducing the cost and toxic side effects.Commonly used polymer materials include PLGA，poly（ethylene-vinyl acetate）（PEVA），collagen，etc.Mooney et al.developed a microporous PLGA matrix loaded with granulocyte-macrophage colonystimulating factor（GM-CSF），danger signals and tumor antigens to construct tumor vaccines，which mimicked an immune response to bacterial infection.The PLGA scaffold releases GM-CSF，acts as a home for the recruited DCs，and together with antigenic tumor lysate and adjuvant CpG ODN to stimulate the activation of DCs，which significantly enhances its localization to lymph nodes resulted in a specific anti-melanoma immune response.(https://www.daowen.com)