Extracellular Vesicles as Drug Carriers for Enzyme Replacement Therapy to Treat CLN2 Batten Disease: Optimization of Drug Administration Routes.

CLN2 Batten disease (BD) is one of a broad class of lysosomal storage disorders that is characterized by the deficiency of lysosomal enzyme, TPP1, resulting in a build-up of toxic intracellular storage material in all organs and subsequent damage. A major challenge for BD therapeutics is delivery of enzymatically active TPP1 to the brain to attenuate progressive loss of neurological functions. To accomplish this daunting task, we propose the harnessing of naturally occurring nanoparticles, extracellular vesicles (EVs). Herein, we incorporated TPP1 into EVs released by immune cells, macrophages, and examined biodistribution and therapeutic efficacy of EV-TPP1 in BD mouse model, using various routes of administration. Administration through intrathecal and intranasal routes resulted in high TPP1 accumulation in the brain, decreased neurodegeneration and neuroinflammation, and reduced aggregation of lysosomal storage material in BD mouse model, CLN2 knock-out mice. Parenteral intravenous and intraperitoneal administrations led to TPP1 delivery to peripheral organs: liver, kidney, spleen, and lungs. A combination of intrathecal and intraperitoneal EV-TPP1 injections significantly prolonged lifespan in BD mice. Overall, the optimization of treatment strategies is crucial for successful applications of EVs-based therapeutics for BD.

Macrophage-Derived Extracellular Vesicles as Drug Delivery Systems for Triple Negative Breast Cancer (TNBC) Therapy.

Efficient targeted delivery of anticancer agents to TNBC cells remains one of the greatest challenges to developing therapies. The lack of tumor-specific markers, aggressive nature of the tumor, and unique propensity to recur and metastasize make TNBC tumors more difficult to treat than other subtypes. We propose to exploit natural ability of macrophages to target cancer cells by means of extracellular vesicles (EVs) as drug delivery vehicles for chemotherapeutic agents, paclitaxel (PTX) and doxorubicin (Dox). We demonstrated earlier that macrophage-derived EVs loaded with PTX (EV-PTX) and Dox (EV-Dox) target cancer cells and exhibited high anticancer efficacy in a mouse model of pulmonary metastases. Herein, we report a manufacture and characterization of novel EV-based drug formulations using different loading procedures that were optimized by varying pH, temperature, and sonication conditions. Selected EV-based formulations showed a high drug loading, efficient accumulation in TNBC cells in vitro, and pronounced anti-proliferation effect. Drug-loaded EVs target TNBC in vivo, including the orthotopic mouse T11 tumors in immune competent BALB/C mice, and human MDA-MB-231 tumors in athymic nu/nu mice, and abolished tumor growth. Overall, EV-based formulations can provide a novel solution to a currently unmet clinical need and reduce the morbidity and mortality of TNBC patients. Graphical Abstract Macrophage-derived extracellular vesicles (EVs) for targeted drug delivery to TNBC tumors. Chemotherapeutics with different water solubility (Dox or PTX, i.e. hydrophilic or hydrophobic drugs, respectively) were loaded into macrophage-derived EVs through parental cells (Dox), or into naïve EVs (Dox or PTX), and their antitumor efficacy was demonstrated in mouse orthotopic TNBC model.

GDNF-expressing macrophages restore motor functions at a severe late-stage, and produce long-term neuroprotective effects at an early-stage of Parkinson's disease in transgenic Parkin Q311X(A) mice.

There is an unmet medical need in the area of Parkinson's disease (PD) to develop novel therapeutic approaches that can stop and reverse the underlying mechanisms responsible for the neuronal death. We previously demonstrated that systemically administered autologous macrophages transfected ex vivo to produce glial cell line-derived neurotrophic factor (GDNF) readily migrate to the mouse brain with acute toxin-induced neuroinflammation and ameliorate neurodegeneration in PD mouse models. We hypothesized that the high level of cytokines due to inflammatory process attracted GDNF-expressing macrophages and ensured targeted drug delivery to the PD brain. Herein, we validated a therapeutic potential of GDNF-transfected macrophages in a transgenic Parkin Q311X(A) mice with slow progression and mild brain inflammation. Systemic administration of GDNF-macrophages at a severe late stage of the disease leaded to a near complete restoration of motor functions in Parkin Q311X(A) mice and improved brain tissue integrity with healthy neuronal morphology. Furthermore, intravenous injections of GDNF-macrophages at an early stage of disease resulted in potent sustained therapeutic effects in PD mice for more than a year after the treatment. Importantly, multiple lines of evidence for therapeutic efficacy were observed including: diminished neuroinflammation and α-synuclein aggregation, increased survival of dopaminergic neurons, and improved locomotor functions. In summary, GDNF-transfected macrophages represent a promising therapeutic strategy for PD at both late- and early-stages of the disease.