HEXA and Sandhoff disease: As part of the enormous potential represented by drug delivery mediated by NPs, we developed a system consisting of polymeric NPs of polylactic acid (PLA) covered with a lysosomal enzyme, β-d-N-acetyl-hexosaminidase A, to evaluate the effectiveness of internalization and functioning of HexA-NP complex in cellular models of Sandhoff disease, one of the most serious disorders among all LSDs [37].