The present invention relates to methods of drug delivery for the treatment of a condition or disease, such as cancer. In one embodiment, the invention provides a method of preparing a multifunctional nanoconjugate of temozolomide (TMZ) by conjugating TMZ in its hydrazide form to a polymalic acid platform. In another embodiment, the polymalic acid platform is conjugated to a monoclonal antibody to transferrin receptor, a trileucine (LLL) moiety, and/or a polyethylene glycol (PEG) moiety. The present invention relates to methods of drug delivery for the treatment of a condition or disease, such as cancer. In one embodiment, the invention provides a method of preparing a multifunctional nanoconjugate of temozolomide (TMZ) by conjugating TMZ in its hydrazide form to a polymalic acid platform. In another embodiment, the polymalic acid platform is conjugated to a monoclonal antibody to transferrin receptor, a trileucine (LLL) moiety, and/or a polyethylene glycol (PEG) moiety.