Pluronic block copolymers enhance the anti-myeloma activity of proteasome inhibitors.

Proteasome inhibitors (PIs) have markedly improved response rates as well as the survival of multiple myeloma (MM) patients over the past decade and have become an important foundation in the treatment of MM patients. Unfortunately, the majority of patients either relapses or becomes refractory to proteasome inhibition. This report describes that both PI sensitive and resistant MM cells display enhanced sensitivity to PI in the presence of synthetic amphiphilic block copolymers, Pluronics (SP1017).

In vivo distribution and antitumor activity of doxorubicin-loaded N-isopropylacrylamide-co-methacrylic acid coated mesoporous silica nanoparticles and safety evaluation.

The objective of this study was to develop and evaluate the antitumor activity and the safety of a delivery system containing mesoporous silica nanoparticles (MSN) coated with pH-responsive poly (N-isopropylacrylamide-co-methacrylic acid; P NIPAM-co-MAA) for doxorubicin (DOX) delivery (P-MSN-DOX) in vitro and in vivo. We reported that P-MSN-DOX nanoparticles (190 ± 30 nm) offered a DOX-loading coefficient of more than 20%. DOX release from the P-MSN-DOX formulation was pH-dependent with enhanced antitumor effects in vitro compared with traditional MSN-DOX, which was weakly cytotoxic due to negligible drug release at tested pHs.