Plasma Cell Myeloma: Biochemical Insights into Diagnosis, Treatment, and Smart Nanocarrier-Based Therapeutic Development.

Plasma cell myeloma (PCM) is classified as a blood cancer and is characterized by the abnormal proliferation of plasma cells in the bone marrow and the excessive production of monoclonal immunoglobulins, which lead to permanent damage to vital organs. Although treatment strategies have improved with the development of proteasome inhibitors (PIs), immunomodulatory drugs (IMiDs), and monoclonal antibodies (mAbs), PCM remains an incurable disease due to its molecular heterogeneity and the development of drug resistance. In this review, we discuss the biochemical and molecular foundations underlying the diagnosis and treatment of PCM, emphasizing both traditional and advanced approaches. Classical methods such as serum protein electrophoresis (SPEP), immunofixation electrophoresis (IFE), and serum free light chain (sFLC) determination are highlighted alongside their integration with highly sensitive techniques like mass spectrometry (MS) and next-generation sequencing (NGS). Special attention is given to nanotechnology-based systems, including liposomes, polymeric nanoparticles (NPs), dendrimers, and hybrid nanocapsules, which enable controlled drug release, targeted delivery, and the minimization of systemic toxicity. Increasingly, nanomaterials are being shown to greatly enhance the biodistribution and pharmacokinetics of anticancer drugs, leading to improved therapeutic effects and escaping resistance mechanisms by employing multifunctional strategies that include dual drug co-encapsulation, pH-sensitive release and theranostic applications. Furthermore, the integration of nanotechnology with immunotherapy platforms represents a paradigm shift toward precision and personalized medicine for the treatment of PCM. Overall, this review views nanotechnology as an enabling technology to improve therapeutic effectiveness, minimize toxicity and open new avenues toward next-generation smart and personalized therapeutics for the treatment of PCM.