PLA–PCL was used to strengthen the polymer, while TPGS was intended to make the loaded compound more permeable though biological membranes [151]; in fact, previous studies showed that this derivative of vitamin E can enhance absorption of drugs by inhibiting the efflux pumps in cancer cells (such as P-gp) while being nontoxic to healthy ones [153,154]. The gene discussed is PGP; the disease is cancer.