Local delivery of dinutuximab from lyophilized silk fibroin foams for treatment of an orthotopic neuroblastoma model

Abstract

Immunotherapy targeting GD2 is a primary treatment for patients with high-risk neuroblastoma. Dinutuximab is a monoclonal antibody with great clinical promise but is limited by side effects such as severe pain. Local delivery has emerged as a potential mechanism to deliver higher doses of therapeutics into the tumor bed, while limiting systemic toxicity. We aim to deliver dinutuximab locally in a lyophilized silk fibroin foam for the treatment of an orthotopic neuroblastoma mouse model. Dinutuximabloaded silk fibroin foams were fabricated through lyophilization. In vitro release profile and bioactivity of the release through complement-dependent cytotoxicity were characterized. MYCN-amplified neuroblastoma cells (KELLY) were injected into the left gland of mice to generate an orthotopic neuroblastoma model. Once the tumor volume reached 100 mm 3 , dinutuximab-, human IgG-, or buffer-loaded foams were implanted into the tumor and growth was monitored using high-resolution ultrasound. Post-resection histology was performed on tumors. Dinutuximab-loaded silk fibroin foams exhibited a burst release, with slow release thereafter in vitro with maintenance of bioactivity. The dinutuximab-loaded foam significantly inhibited xenograft tumor growth compared to IgG-and buffer-loaded foams. Histological analysis revealed the presence of dinutuximab within the tumor and neutrophils and macrophages infiltrating into dinutuximab-loaded silk foam. Tumors treated with local dinutuximab had decreased MYCN expression on histology compared to control or IgG-treated tumors. Silk fibroin foams offer a mechanism for local release of dinutuximab within the neuroblastoma tumor. This local delivery achieved a significant decrease in tumor growth rate in a mouse orthotopic tumor model. K E Y W O R D SCh14.18, dinutuximab, immunotherapy, local delivery, neuroblastoma, silk fibroin

Development of a dinutuximab delivery system using silk foams for GD2 targeted neuroblastoma cell death

“…In order to fabricate a sustained release system for DNX, silk foams containing DNX or buffer‐only (control) were fabricated via lyophilization as previously described 31 . The silk foams serve to stabilize antibodies and to control antibody release through entrapment and diffusion 30,32‐34 .…”

“…Previously, in vitro CDC has been used as to assess cellular responses to GD2 antibodies 15,31,39,40 . One method of evaluation is a calcein release assay, where live cells are stained with calcein AM, and complement induced cell lysis causes the release of calcein 41 .…”

“…Fluorescence‐activated cell sorting (FACS) was performed at the University of Massachusetts Medical Center (Worcester, MA) using an Aria II cell sorter (BD Biosciences, Franklin Lakes, NJ) as previously described 31 . Briefly, KELLY cells were made into a single cell suspension and washed twice with PBS.…”

“…Previous work has shown the effectiveness of delivering DNX from lyophilized silk fibroin foams in vivo 31 . Intra‐tumoral delivery of DNX‐loaded silk fibroin foams resulted in decreased tumor growth rate in an in vivo orthotopic model of neuroblastoma 31 .…”

Silk Polymers and Nanoparticles: A Powerful Combination for the Design of Versatile Biomaterials

“…These foams can be used as a drug delivery vehicles for bioactive molecules, and their degradation has been tuned using pre-loaded enzymes (Chambre et al, 2020 ). Likewise, these foams have been loaded with Dinutuximab, a monoclonal antibody with clinical potential for patients with high-risk neuroblastoma (Ornell et al, 2020 ). These silk foams induced a significant decrease in tumor growth rate in a mouse orthotopic tumor model.…”