CD47 Aptamer-Decorated Fluorescent POSS Hybrid Nanoparticles as a Biohybrid Interface for Probing Prostate Cancer–Macrophage Interactions

Prostate cancer remains a major clinical challenge, partly due to tumour–immune interactions that contribute to immune evasion and therapeutic resistance. The CD47–SIRPα axis is a key macrophage-associated immune recognition pathway; and materials-oriented platforms that allow preliminary investigation of tumour–macrophage interaction patterns remain valuable. Here, we report an optically traceable biohybrid nanoplatform based on CD47 aptamer-functionalized fluorescent carboxyl-functional MMES-POSS hybrid nanoparticles. The nanoparticles were synthesized within 5 min using UV-induced free-radical emulsion polymerization in an ethanol–water system and exhibited spherical morphology, SEM-derived dry-state mean diameters below 100 nm, negative surface charge, and retained fluorescence due to RITC encapsulation within the crosslinked hybrid matrix; however, DLS measurements revealed pronounced aggregation and polydispersity in aqueous dispersion. SEM and EDX provided complementary evidence of nanoparticle morphology and elemental composition, whereas zeta potential and Nanodrop measurements provided evidence consistent with surface functionalization, and FTIR confirmed retention of the core POSS, carbonyl, and RITC-associated chemistry. In a PC-3/THP-1 macrophage co-culture model, Annexin V–FITC/PI flow cytometry showed a concentration-dependent redistribution of cell populations, with the most pronounced early apoptotic enrichment observed at 2 µg/mL. However, pairwise exploratory comparisons among concentrations did not reach statistical significance, and this is discussed as a limitation of the present exploratory dose–response characterization. These findings indicate preliminary interaction-associated response patterns rather than definitive receptor-specific targeting or therapeutic CD47–SIRPα blockade. Overall, this modular POSS-based biohybrid interface provides a materials-oriented platform for probing prostate cancer–macrophage interaction profiles and guiding future mechanistic validation studies.