**Mesoporous Silica Nanoparticles as Carriers for Therapeutic Biomolecules**

**Rafael R. Castillo 1,2,3,**†**, Daniel Lozano 1,2,3,**† **and María Vallet-Regí 1,2,3,\***


Received: 13 April 2020; Accepted: 1 May 2020; Published: 7 May 2020

**Abstract:** The enormous versatility of mesoporous silica nanoparticles permits the creation of a large number of nanotherapeutic systems for the treatment of cancer and many other pathologies. In addition to the controlled release of small drugs, these materials allow a broad number of molecules of a very different nature and sizes. In this review, we focus on biogenic species with therapeutic abilities (proteins, peptides, nucleic acids, and glycans), as well as how nanotechnology, in particular silica-based materials, can help in establishing new and more efficient routes for their administration. Indeed, since the applicability of those combinations of mesoporous silica with bio(macro)molecules goes beyond cancer treatment, we address a classification based on the type of therapeutic action. Likewise, as illustrative content, we highlight the most typical issues and problems found in the preparation of those hybrid nanotherapeutic materials.

**Keywords:** mesoporous silica; therapeutic biomolecules; proteins; peptides; nucleic acids; glycans
