Multiple sclerosis (MS) is an autoimmune disease affecting the central nervous system that causes significant disability and healthcare burden. The treatment of MS has evolved over the past three decades with development of new, high efficacy disease modifying therapies targeting various mechanisms including immune modulation, immune cell suppression or depletion and enhanced immune cell sequestration. Emerging therapies include CNS-penetrant Bruton's tyrosine kinase inhibitors and autologous hematopoietic stem cell transplantation as well as therapies aimed at remyelination or neuroprotection. Therapy development for progressive MS has been more challenging with limited efficacy of current approved agents for inactive disease and older patients with MS. The aim of this review is to provide a broad overview of the current therapeutic landscape for MS.

Chen et al. recently carried out self-assembled growth of epitaxial sub-10 nm erbium disilicide (C32, hP3) nanowires on Si(001). They pointed out that the success of this self-assembly process is due to asymmetric lattice mismatches in the two orthogonal crystallographic directions of the two materials, i.e. [0001]ErSi2/[110]si,+6.5% and [1120] RESi2/[110]si,-1.3%. In this paper, we have established experimentally that (Er1-xGdx)Si2 and (Er 1-xSmx)Si2 exist with values of x from 0 to 1 and that their lattice parameters follow Vegard's law. Since the binary GdSi2 and SmSi2 end members in each of these ternary systems have a and c unit cell parameters greater than those of the ErSi 2 end member, we have determined that an optimal lattice mismatch can be achieved with the Si substrate at a composition of (Er 0.45Gd0.55)Si2 and (Er0.62Sm 0.38)Si2. It is reasonable to expect a higher quality of self-assembled nanowire growth on Si by employing these ternary silicides. A review of the atomic sizes of the rare earth metal elements of the lanthanide series indicates that many of the binary disilicides, when exhibiting the C32 structure, should have a tendency to form ternary and higher-order disilicides. These materials would offer many possibilities for the growth of suicide nanowires with interesting electronic, magnetic and optical properties.