The present invention relates to bone cements and, more particularly, to acrylic-based orthopedic bone cements, their use in spinal applications, and methods for making the same. An embodiment of the present invention provides a method of grafting PMMA brushes on cross-linked PMMA nanospheres comprising at least one of the following steps: performing a hydrolysis reaction of surface methyl ester groups of said cross-linked PMMA nanospheres to form surface carboxylic acid groups of said cross-linked PMMA nanospheres; forming a 2-aminoethyl acrylate compound; coupling said surface carboxylic acid groups of said cross-linked PMMA nanospheres with said 2-aminoethyl acrylate compound to form a coupled compound with an initiating site; and grafting said PMMA brushes onto said initiating site. Another embodiment of the present invention includes an orthopedic bone cement including cross-linked PMMA nanospheres comprising PMMA brushes prepared by this method, and a monomer, wherein polymer to monomer ratio is between about 1:1 and 1.3:1.