Conventional immune cell therapies often require genetic engineering, increasing cost and raising safety concerns from off-tumor recognition. Here, we present a "reverse-targeting" strategy that engineers tumor cell surfaces to drive localized, selective immune cell interactions at the tumor site. We designed a dermatan sulfate (DmS)-conjugated amphiphilic lipid polymer, to form a uniform coating. PEG improves colloidal stability and displays DmS, a natural glycosaminoglycan that binds CD44, an adhesion receptor widely expressed on circulating localized immune engagement to boost antitumor activity while minimizing systemic off-target effects. This non-genetic modular surface engineering approach offers a stramlined, scalable route to tumor-specific immune modulation and may complement existing immunotherapies.