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

Intravenous pegylated liposomal prednisolone outperforms intramuscular methylprednisolone in treating rheumatoid arthritis flares:A randomized controlled clinical trial

Glucocorticoids (GCs) are potent anti-inflammatory drugs but their use is limited by systemic exposure leading to toxicity. Targeted GC delivery to sites of inflammation via encapsulation in long-circulating liposomes may improve the therapeutic index. We performed a randomized, double-blind, active-controlled, multi-center study in which intravenously (i.v.) administered pegylated liposomal prednisolone sodium phosphate (Nanocort) was compared to equipotent intramuscular (i.m.) methylprednisolone acetate (Depo-Medrol®; i.e. a current standards-of-care for treating flares in rheumatoid arthritis patients). We enrolled 172 patients with active arthritis who met all eligibility criteria, eventually resulting in 150 patients randomized in three groups: (1) Nanocort 75 mg i.v. infusion plus i.m. saline injection; (2) Nanocort 150 mg i.v. infusion plus i.m. saline injection; and (3) Depo-Medrol® 120 mg i.m. injection plus i.v. saline infusion. Dosing in each group occurred at baseline and on day 15 (week 2). Study visits occurred at week 1, 2, 3, 4, 6, 8 and 12, to assess both efficacy and safety. The primary endpoint was the "European League Against Rheumatism" (EULAR) responder rate at week 1. Safety was determined by the occurrence of adverse events during treatment and 12 weeks of follow-up. Treatment with Nanocort was found to be superior to Depo-Medrol® in terms of EULAR response at week 1, with p-values of 0.007 (good response) and 0.018 (moderate response). Treatments were well tolerated with a comparable pattern of adverse events in the three treatment groups. However, the Nanocort groups had a higher incidence of hypersensitivity reactions during liposome infusion. Our results show that liposomal Nanocort is more effective than Depo-Medrol® in treating patients with rheumatoid arthritis flares and has similar safety. This is the first clinical study in a large patient population showing that i.v. administered targeted drug delivery with a nanomedicine formulation improves the therapeutic index of glucocorticoids.status: publishe

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

Effect of formulation and processing parameters on the size of mPEG-b-p(HPMA-Bz) polymeric micelles

Micelles composed of block copolymers of poly(ethylene glycol)-b-poly(N-2-benzoyloxypropyl methacrylamide) (mPEG-b-p(HPMA-Bz)) have shown great promise as drug-delivery carriers due to their excellent stability and high loading capacity. In the present study, parameters influencing micelle size were investigated to tailor sizes in the range of 25-100 nm. Micelles were prepared by a nanoprecipitation method, and their size was modulated by the block copolymer properties such as molecular weight, their hydrophilic-to-hydrophobic ratio, homopolymer content, as well as formulation and processing parameters. It was shown that the micelles have a core-shell structure using a combination of dynamic light scattering and transmission electron microscopy analysis. By varying the degree of polymerization of the hydrophobic block (NB) between 68 and 10, at a fixed hydrophilic block mPEG5k (NA = 114), it was shown that the hydrophobic core of the micelle was collapsed following the power law of (NB × Nagg)1/3. Further, the calculated brush height was similar for all the micelles examined (10 nm), indicating that crew-cut micelles were made. Both addition of homopolymer and preparation of micelles at lower concentrations or lower rates of addition of the organic solvent to the aqueous phase increased the size of micelles due to partitioning of the hydrophobic homopolymer chains to the core of the micelles and lower nucleation rates, respectively. Furthermore, it was shown that by using different solvents, the size of the micelles substantially changed. The use of acetone, acetonitrile, ethanol, tetrahydrofuran, and dioxane resulted in micelles in the size range of 45-60 nm after removal of the organic solvents. The use of dimethylformamide and dimethylsulfoxide led to markedly larger sizes of 75 and 180 nm, respectively. In conclusion, the results show that by modulating polymer properties and processing conditions, micelles with tailorable sizes can be obtained

Tunable polymeric micelles for taxane and corticosteroid co-delivery

Nanomedicine holds promise for potentiating drug combination therapies. Increasing (pre)clinical evidence is available exemplifying the value of co-formulating and co-delivering different drugs in modular nanocarriers. Taxanes like paclitaxel (PTX) are widely used anticancer agents, and commonly combined with corticosteroids like dexamethasone (DEX), which besides for suppressing inflammation and infusion reactions, are increasingly explored for modulating the tumor microenvironment towards enhanced nano-chemotherapy delivery and efficacy. We here set out to develop a size- and release rate-tunable polymeric micelle platform for co-delivery of taxanes and corticosteroids. We synthesized amphiphilic mPEG-b-p(HPMAm-Bz) block copolymers of various molecular weights and used them to prepare PTX and DEX single- and double-loaded micelles of different sizes. Both drugs could be efficiently co-encapsulated, and systematic comparison between single- and co-loaded formulations demonstrated comparable physicochemical properties, encapsulation efficiencies, and release profiles. Larger micelles showed slower drug release, and DEX release was always faster than PTX. The versatility of the platform was exemplified by co-encapsulating two additional taxane-corticosteroid combinations, demonstrating that drug hydrophobicity and molecular weight are key properties that strongly contribute to drug retention in micelles. Altogether, our work shows that mPEG-b-p(HPMAm-Bz) polymeric micelles serve as a tunable and versatile nanoparticle platform for controlled co-delivery of taxanes and corticosteroids, thereby paving the way for using these micelles as a modular carrier for multidrug nanomedicine. Graphical abstract: [Figure not available: see fulltext.

Effect of Radical Polymerization Method on Pharmaceutical Properties of Π Electron-Stabilized HPMA-Based Polymeric Micelles

Polymeric micelles are among the most extensively used drug delivery systems. Key properties of micelles, such as size, size distribution, drug loading, and drug release kinetics, are crucial for proper therapeutic performance. Whether polymers from more controlled polymerization methods produce micelles with more favorable properties remains elusive. To address this question, we synthesized methoxy poly(ethylene glycol)-b-(N-(2-benzoyloxypropyl)methacrylamide) (mPEG-b-p(HPMAm-Bz)) block copolymers of three different comparable molecular weights (∼9, 13, and 20 kDa), via both conventional free radical (FR) and reversible addition-fragmentation chain transfer (RAFT) polymerization. The polymers were subsequently employed to prepare empty and paclitaxel-loaded micelles. While FR polymers had relatively high dispersities (Đ ∼ 1.5-1.7) compared to their RAFT counterparts (Đ ∼ 1.1-1.3), they formed micelles with similar pharmaceutical properties (e.g., size, size distribution, critical micelle concentration, cytotoxicity, and drug loading and retention). Our findings suggest that pharmaceutical properties of mPEG-b-p(HPMAm-Bz) micelles do not depend on the synthesis route of their constituent polymers