Development of a novel CD52 functionalised nanoparticle for the targeting of Chronic Lymphocytic Leukaemia

Abstract

Nanomedicine has been recognised as a next-generation technology for the treatment and management of many disease states, including blood cancers. The term nanotechnology was first coined in 1974 and, is at the interface of biology, chemistry and physics nanomedicine has transformed over the past two decades to a $40 billion market. Chronic lymphocytic leukaemia (CLL) is a highly heterogeneous B cell malignancy, with a variable clinical course; dependent on patient characteristics and the presence of relevant prognostic markers. Though there has been significant progress in the clinical translation of therapies for the management of CLL, frontline therapies consist of chemoimmunotherapies targeting CLL cell surface markers such as CD20 and CD52. CD52 is a long-established CLL therapeutic target; with the anti-CD52 monoclonal antibody alemtuzumab being approved as a targeted therapy in the management of CLL in 2001. Here, we propose the development of a novel, anti-CD52 functionalised nanoparticle for the treatment of CLL as a proof-of-concept therapeutic model. We propose CD52 as a suitable cell surface marker for therapeutic targeting in CLL, and utilising characterisation techniques such as Nanoparticle Tracking Analysis (NTA), scanning electron microscopy (SEM) and flow cytometry demonstrate successful functionalisation and characterisation of Fe2O3 nanoparticles with anti-CD52 monoclonal antibody (Fe2O3@CD52). Qualitatively and quantitatively, we demonstrate enhanced interaction and uptake of Fe2O3@CD52 nanoparticles in CLL cells when compared to normal B cells. The data suggests clathrin-mediated endocytosis as a possible mechanism of uptake of nanoparticles by CLL cells. Additionally, we report the reduction in adherence of patient-derived CLL cells following treatment with nanoparticles to endothelial monolayers under physiologically-relevant fluid shear flow conditions. Finally, we demonstrate that my novel nanoparticle can significantly induce apoptosis in patient-derived CLL cells over 8 and 24 hours, when compared to non-functionalised (Fe2O3@APTES) nanoparticles. We report that Fe2O3@CD52 is equally potent in inducing apoptosis in cells with favourable or poor prognostic markers. Additionally, we demonstrate that the inclusion of the purine analogue, fludarabine; or the addition of an additional targeting monoclonal antibody (yielding double-functionalised nanoparticles) to the surface of Fe2O3@CD52 does not enhance its activity.

In conclusion, this thesis aims to bridge the gap between haemato-oncology and nanotechnology to provide some of the insights required to address the unmet need for a targeted nanotherapeutic in the management of blood cancers, and CLL in particular. Using multiple validated technologies, here we present the findings of a robust study with the potential to contribute to the ever-expanding fields of both nanotherapeutics and haemato-oncology by providing the opportunity for the further progress and development of novel, targeted therapeutics for haematological malignancies.