Current Trends and Challenges in the Clinical Translation of Nanoparticulate Nanomedicines: Pathways for Translational Development and Commercialization

The use of nanotechnology in medicine has the potential to have a major impact on human health for the prevention, diagnosis, and treatment of diseases. One particular aspect of the nanomedicine field which has received a great deal of attention is the design and development of nanoparticulate nanomedicines (NNMs) for drug delivery (i.e., drug-containing nanoparticles). NNMs are intended to deliver drugs via various mechanisms: solubilization, passive targeting, active targeting, and triggered release. The NNM approach aims to increase therapeutic efficacy, decrease the therapeutically effective dose, and/or reduce the risk of systemic side effects. In order to move a NNM from the bench to the bedside, several experimental challenges need to be addressed. This review will discuss the current trends and challenges in the clinical translation of NNMs as well as the potential pathways for translational development and commercialization. Key issues related to the clinical development of NNMs will be covered, including biological challenges, large-scale manufacturing, biocompatibility and safety, intellectual property (IP), government regulations, and overall cost-effectiveness in comparison to current therapies. These factors can impose significant hurdles limiting the appearance of NNMs on the market, irrelevant of whether they are therapeutically beneficial or not

Quercetin Liposomal Nanoformulation for Ischemia and Reperfusion Injury Treatment

PD/BD/135264/2017 UID/DTP/04138/2020 UIDP/04138/2020 UIDP/04378/2020 UIDB/04378/2020 LA/P/0140/2020 UIDB/50006/2020 UIDB/00100/2020Ischemia and reperfusion injury (IRI) is a common complication caused by inflammation and oxidative stress resulting from liver surgery. Current therapeutic strategies do not present the desirable efficacy, and severe side effects can occur. To overcome these drawbacks, new therapeutic alternatives are necessary. Drug delivery nanosystems have been explored due to their capacity to improve the therapeutic index of conventional drugs. Within nanocarriers, liposomes are one of the most successful, with several formulations currently in the market. As improved therapeutic outcomes have been demonstrated by using liposomes as drug carriers, this nanosystem was used to deliver quercetin, a flavonoid with anti-inflammatory and antioxidant properties, in hepatic IRI treatment. In the present work, a stable quercetin liposomal formulation was developed and characterized. Additionally, an in vitro model of ischemia and reperfusion was developed with a hypoxia chamber, where the anti-inflammatory potential of liposomal quercetin was evaluated, revealing the downregulation of pro-inflammatory markers. The anti-inflammatory effect of quercetin liposomes was also assessed in vivo in a rat model of hepatic IRI, in which a decrease in inflammation markers and enhanced recovery were observed. These results demonstrate that quercetin liposomes may provide a significant tool for addressing the current bottlenecks in hepatic IRI treatment.publishersversionpublishe

Distribution of technetium-99m PEG-liposomes during oligofructose-induced laminitis development in horses

Liposomes are phospholipid nanoparticles used for targeted drug delivery. This study aimed to determine whether intravenous liposomes accumulate in lamellar tissue during laminitis development in horses so as to assess their potential for targeted lamellar drug delivery. Polyethylene-glycol (PEG) coated liposomes were prepared according to the film hydration method and labelled using Tc-hexamethyl-propylene-amine-oxime. Six horses received 10 g/kg oligofructose via nasogastric tube to induce laminitis, and four control horses received water via nasogastric tube. All horses received 300 μmol Tc-PEG-liposomes (5.5 GBq) plus 5.5 μmol/kg PEG-liposomes by slow intravenous infusion. Scintigraphic imaging was performed at 0, 6 and 12 h post-infusion. Technetium-99m liposome uptake was measured in regions of interest over the hoof, fetlock and metacarpus. At the study end-point horses were euthanased, tissue samples collected and tissue liposome levels were calculated as the percentage of the injected dose of Tc-liposomes per kilogram of tissue. Data were analysed non-parametrically.All horses receiving oligofructose developed clinical and histological signs of laminitis. Technetium-99m liposome uptake in the hoof increased with time in laminitis horses (P = 0.04), but decreased with time in control horses (P = 0.01). Technetium-99m liposome levels in lamellar tissue from laminitis horses were 3.2-fold higher than controls (P = 0.02) and were also higher in laminitis vs. control skin, muscle, jejunum, colon, and kidney (P < 0.05). Liposomes accumulated in lamellar tissue during oligofructose-induced laminitis development and demonstrated potential for targeted lamellar drug delivery in acute laminitis. This study provides further evidence that lamellar inflammation occurs during laminitis development. Liposome accumulation also occurred in the skin, muscle, jejunum, colon and kidneys, suggesting systemic inflammation in this model

Liposomal prednisolone promotes macrophage lipotoxicity in experimental atherosclerosis

Atherosclerosis is a lipid-driven inflammatory disease, for which nanomedicinal interventions are under evaluation. Previously, we showed that liposomal nanoparticles loaded with prednisolone (LN-PLP) accumulated in plaque macrophages, however, induced proatherogenic effects in patients. Here, we confirmed in low-density lipoprotein receptor knockout (LDLr−/−) mice that LN-PLP accumulates in plaque macrophages. Next, we found that LN-PLP infusions at 10 mg/kg for 2 weeks enhanced monocyte recruitment to plaques. In follow up, after 6 weeks of LN-PLP exposure we observed (i) increased macrophage content, (ii) more advanced plaque stages, and (iii) larger necrotic core sizes. Finally, in vitro studies showed that macrophages become lipotoxic after LN-PLP exposure, exemplified by enhanced lipid loading, ER stress and apoptosis. These findings indicate that liposomal prednisolone may paradoxically accelerate atherosclerosis by promoting macrophage lipotoxicity. Hence, future (nanomedicinal) drug development studies are challenged by the multifactorial nature of atherosclerotic inflammation

PEG Minocycline-Liposomes Ameliorate CNS Autoimmune Disease

Minocycline is an oral tetracycline derivative with good bioavailability in the central nervous system (CNS). Minocycline, a potent inhibitor of matrix metalloproteinase (MMP)-9, attenuates disease activity in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Potential adverse effects associated with long-term daily minocycline therapy in human patients are concerning. Here, we investigated whether less frequent treatment with long-circulating polyethylene glycol (PEG) minocycline liposomes are effective in treating EAE.Performing in vitro time kinetic studies of PEG minocycline-liposomes in human peripheral blood mononuclear cells (PBMCs), we determined that PEG minocycline-liposome preparations stabilized with CaCl(2) are effective in diminishing MMP-9 activity. Intravenous injections of PEG minocycline-liposomes every five days were as effective in ameliorating clinical EAE as daily intraperitoneal injections of minocycline. Treatment of animals with PEG minocycline-liposomes significantly reduced the number of CNS-infiltrating leukocytes, and the overall expression of MMP-9 in the CNS. There was also a significant suppression of MMP-9 expression and proteolytic activity in splenocytes of treated animals, but not in CNS-infiltrating leukocytes. Thus, leukocytes gaining access to the brain and spinal cord require the same absolute amount of MMP-9 in all treatment groups, but minocycline decreases the absolute cell number.Our data indicate that less frequent injections of PEG minocycline-liposomes are an effective alternative pharmacotherapy to daily minocycline injections for the treatment of CNS autoimmune diseases. Also, inhibition of MMP-9 remains a promising treatment target in EAE and patients with MS

Ultrasound-directed enzyme-prodrug therapy (UDEPT) using self-immolative doxorubicin derivatives

Background: Enzyme-activatable prodrugs are extensively employed in oncology and beyond. Because enzyme concentrations and their (sub)cellular compartmentalization are highly heterogeneous in different tumor types and patients, we propose ultrasound-directed enzyme-prodrug therapy (UDEPT) as a means to increase enzyme access and availability for prodrug activation locally. Methods: We synthesized β-glucuronidase-sensitive self-immolative doxorubicin prodrugs with different spacer lengths between the active drug moiety and the capping group. We evaluated drug conversion, uptake and cytotoxicity in the presence and absence of the activating enzyme β-glucuronidase. To trigger the cell release of β-glucuronidase, we used high-intensity focused ultrasound to aid in the conversion of the prodrugs into their active counterparts. Results: More efficient enzymatic activation was observed for self-immolative prodrugs with more than one aromatic unit in the spacer. In the absence of β-glucuronidase, the prodrugs showed significantly reduced cellular uptake and cytotoxicity compared to the parent drug. High-intensity focused ultrasound-induced mechanical destruction of cancer cells resulted in release of intact β-glucuronidase, which activated the prodrugs, restored their cytotoxicity and induced immunogenic cell death. Conclusion: These findings shed new light on prodrug design and activation, and they contribute to novel UDEPT-based mechanochemical combination therapies for the treatment of cancer

Monitoring EPR Effect Dynamics during Nanotaxane Treatment with Theranostic Polymeric Micelles

Cancer nanomedicines rely on the enhanced permeability and retention (EPR) effect for efficient target site accumulation. The EPR effect, however, is highly heterogeneous among different tumor types and cancer patients and its extent is expected to dynamically change during the course of nanochemotherapy. Here the authors set out to longitudinally study the dynamics of the EPR effect upon single- and double-dose nanotherapy with fluorophore-labeled and paclitaxel-loaded polymeric micelles. Using computed tomography-fluorescence molecular tomography imaging, it is shown that the extent of nanomedicine tumor accumulation is predictive for therapy outcome. It is also shown that the interindividual heterogeneity in EPR-based tumor accumulation significantly increases during treatment, especially for more efficient double-dose nanotaxane therapy. Furthermore, for double-dose micelle therapy, tumor accumulation significantly increased over time, from 7% injected dose per gram (ID g–1) upon the first administration to 15% ID g–1 upon the fifth administration, contributing to more efficient inhibition of tumor growth. These findings shed light on the dynamics of the EPR effect during nanomedicine treatment and they exemplify the importance of using imaging in nanomedicine treatment prediction and clinical translation