Synthesis and preliminary evaluation of 99mTc-Hynic-fragments [F(ab')2 and F(ab')] of Rituximab as radioimmunoscintigraphic agents for patients with Non-Hodgkin's lymphoma

This study was to evaluate the potential of 99mTc-Hynic-fragments of Rituximab as radioimmunoscintigraphic agents for diagnosis of patients with Non-Hodgkin's Lymphoma (NHL). Rituximab was digested with immobilized pepsin and papain to yield F(ab')2-Rituximab and F(ab')-Rituximab fragments respectively. Purified fragments were characterized by SE-HPLC and SDS-PAGE and subsequently radiolabeled with technetium-99m using Hynic as bifunctional chelator. The 99mTc-Hynic-F(ab')2-Rituximab and 99mTc-Hynic-F(ab')-Rituximab exhibited good in-vitro stability and specificity to Raji cells. Biodistribution studies demonstrated rapid pharmacokinetics and clearance predominantly through renal route. •F(ab')2-Rituximab and F(ab')-Rituximab prepared and characterized by SDS-PAGE and SE-HPLC.•Fragments of Rituximab conjugated with Hynic and radiolabeled with 99mTc.•99mTc-Hynic-F(ab')2/F(ab')-Rituximab exhibited good in vitro stability up to 24 h.•In vitro cell binding studies confirmed specificity of radioimmunoconjugates to CD20 antigen.•99mTc labeled Rituximab fragments cleared predominantly through the renal route.