The use of nanotechnology in medicine, also called Nanomedicine has been a great promise in the last decades since was supposed to find solutions for delivery drugs, cure diseases and reduce side effects for toxic drugs. 
The first liposomal formulation (Doxil®) was approved in 1995 rising high hopes that nanotechnology could effectively end cancer. Nevertheless, only a few nanomedicines have entered the clinic and cancer-related deaths have continued to rise worldwide. 
The reasons for the lack of success of Nanomedicine in cancer, but also for other diseases are known. First, most nanoparticles (ca. 99%) are not able to reach the tumor, largely due to the activity of our immune system, which senses and removes them. Second, nanoparticles often present critical problems of biodegradability and clearance, leading to their accumulation and toxicity. Third, the nanoparticles that reach the tumor are still too few or their cellular up-load too low to elicit a significant anti-tumor effect. 
In this talk we will analyse these problems, and some solutions will be presented to e.g. eliminate the particles from the body of the animals, to improve the targeting towards desired organs and to study the crossing of body barriers. 

Acknowledgments: We wish to thank the European Union’s Horizon 2020 research and innovation programme under grant agreement No 964386 (FET Open Mimic-Key project). 

References:
[1] P. Picchetti et al. ACS Nano 2021, 15, 9701–9716 
[2] M. Sancho Albero et al. Adv. Healthcare Mater. 2023,12, 2202932 
[3] M. Sancho Albero et al. Nanoscale, 2023, 15, 14628-14640 
[4] P. Picchetti et al. J. Am. Chem. Soc. 2023, 145, 22896-22902. 
[5] P. Picchetti et al J. Am. Chem. Soc. 2023, 145, 22903-22912.