Abstract

Obesity imposes optical, vascular, metabolic, and pharmacokinetic constraints that blunt the performance of 
photothermal therapy and photodynamic therapy while exacerbating off-target toxicity. Enlarged adipose 
depots scatter and absorb light differently from lean tissues, abnormal vasculature and extracellular matrix 
stiffening restrict convection and oxygenation, and dyslipidemia reshapes nanoparticle coronas and 
mononuclear phagocyte uptake. Nanomaterials overcome these barriers by concentrating energy-absorbing 
chromophores and photosensitizers in tumors, shifting excitation into near-infrared windows with deeper 
penetration, converting endogenous metabolites into oxygen for photochemistry, and furnishing real-time 
imaging to calibrate heat and singlet oxygen generation. Gold, carbon, semiconducting polymer, and 
upconversion platforms improve photothermal conversion and spatial precision; porphyrin, phthalocyanine, 
BODIPY, aggregation-induced emission photosensitizer, and metal–organic framework constructs upgrade 
photodynamic yield in hypoxic and lipid-rich microenvironments. Ligand decoration for endothelial, tumor, and 
myeloid targets typical of obese tumors, albumin hitchhiking, and stimuli-responsive shells align delivery with 
pathophysiology. This review evaluates how nanotechnology elevates energy absorption, tumor targeting, and 
therapeutic precision in high-BMI patients and outlines design, dosing, safety, and translational guardrails that 
convert optical energy into durable cancer control without collateral metabolic harm.