(P20-031-25) Adipose Stromal Stem Cell-Targeted Nanoparticles: Targeted Delivery of Resveratrol for Inducing Beige Adipocyte Formation

Objectives: Trans-resveratrol (R) induces adipose stromal stem cell (ASC) differentiation into beige adipocytes in white adipose tissue (WAT) to combat obesity, but poor bioavailability and target specificity limit its use. Our previous ASC targeting peptide 1-coated R-loaded nanoparticles (ASC1- R-NPs) can bind to the ΔDCN receptor on ASCs, delivering R to induce inguinal WAT (iWAT) browning in obese mice. Here, we developed a new ASC-targeting peptide, ASC2, using a combination of computational modeling, molecular docking, and in-house adaptive peptide design algorithms. We hypothesize that ASC2-R-NPs outperform ASC1-R-NPs in ASC target specificity, R delivery to ASCs, beige cell formation, and iWAT accumulation in obese mice.

Methods: ASC1 and ASC2-targeted NPs were prepared by coating R-NPs with ASC1 or ASC2 peptides. NP size was measured using Malvern Zetasizer. Fluorescent dyes were incorporated into these NPs, NP binding and uptake in ΔDCN-transduced 3T3-L1 cells (ΔDCN cells) were analyzed using a fluorescence microscopy, while iWAT target specificity of intravenously administered NPs in mice was assessed using an in vivo imaging system. ΔDCN cells were treated with non-targeted R- NPs, ASC1-R-NPs, and ASC2-R-NPs at an R dose of 50 µM, and cellular R content was quantified using HPLC. The mRNA levels of browning markers in ΔDCN cells were measured using real time-PCR.

Results: The mean NP size was below 110 nm. Both ASC1-NPs and ASC2-NPs exhibited significantly enhanced binding and uptake in ΔDCN cells. Both ASC1-R-NPs and ASC2-R-NPs increased cellular R content compared to non-targeted R-NPs, with ASC1-R-NPs causing a 1.6-fold increase and ASC2-R-NPs causing a 2.5-fold increase. Additionally, ASC1-R-NPs and ASC2-R-NPs increased Tmem26 expression by 1.8-fold and 4.8-fold, and CD137 expression by 1.5-fold and 1.7- fold, respectively. ASC2-NPs demonstrated significantly higher accumulation in iWAT and lower accumulation in the liver than ASC1-NPs in mice.

Conclusions: ASC2-R-NPs, compared to ASC1-R-NPs, exhibited significantly higher ASC target specificity, resulting in increased cellular R delivery, beige adipocyte formation, and reduced off-target effects. This novel ASC2 peptide-based delivery system may portend a potential breakthrough for combating obesity through browning WAT.

Funding Sources: This study funded by ASU and Mayo Clinic Grants.