**Interactions of Nanoparticles and Biosystems: Microenvironment of Nanoparticles and Biomolecules in Nanomedicine**

**Carlota Auría-Soro 1,2, Tabata Nesma 1, Pablo Juanes-Velasco 1, Alicia Landeira-Viñuela 1, Helena Fidalgo-Gomez 1, Vanessa Acebes-Fernandez 1, Rafael Gongora 1, María Jesus Almendral Parra 2, Raúl Manzano-Roman 3,\* and Manuel Fuentes 1,3,\***


Received: 15 July 2019; Accepted: 18 September 2019; Published: 24 September 2019

**Abstract:** Nanotechnology is a multidisciplinary science covering matters involving the nanoscale level that is being developed for a grea<sup>t</sup> variety of applications. Nanomedicine is one of these attractive and challenging uses focused on the employment of nanomaterials in medical applications such as drug delivery. However, handling these nanometric systems require defining specific parameters to establish the possible advantages and disadvantages in specific applications. This review presents the fundamental factors of nanoparticles and its microenvironment that must be considered to make an appropriate design for medical applications, mainly: (i) Interactions between nanoparticles and their biological environment, (ii) the interaction mechanisms, (iii) and the physicochemical properties of nanoparticles. On the other hand, the repercussions of the control, alter and modify these parameters in the biomedical applications. Additionally, we briefly report the implications of nanoparticles in nanomedicine and precision medicine, and provide perspectives in immunotherapy, which is opening novel applications as immune-oncology.

**Keywords:** nanoparticles; interactions; protein corona; nanomedicine; biomolecules
