Nano-enabled medicinal products: time for an international advanced community?

In depth characterization of physicochemical Critical Quality Attributes of a clinical drug-dendrimer conjugate

A deep and detailed understanding of drug-dendrimer conjugates key properties is needed to define the critical quality attributes that affect drug product performance. The characterization must be executed both in the formulation media and in biological matrices. This, nevertheless, is challenging on account of a very limited number of suitable, established methods for characterizing the physicochemical properties, stability, and interaction with biological environment of complex drug-dendrimer conjugates. In order to fully characterize AZD0466, a drug-dendrimer conjugate currently under clinical development by AstraZeneca, a collaboration was initiated with the European Nanomedicine Characterisation Laboratory to deploy a state-of-the-art multi-step approach to measure physicochemical properties. An incremental complexity characterization approach was applied to two batches of AZD0466 and the corresponding dendrimer not carrying any drug, SPL-8984. Thus, the aim of this work is to guide in depth characterization efforts in the analysis of drug-dendrimer conjugates. Additionally, it serves to highlight the importance of using the adequate complementary techniques to measure physical and chemical stability in both simple and biological media, to drive a complex drug-dendrimer conjugate product from discovery to clinical development.

Advances in nanoenabled 3D matrices for cartilage repair

Cartilage repair strategies are evolving at a fast pace with technology development. Matrices that offer multifaceted functions and a full adaption to the cartilage defect are of pivotal interest. Current cartilage repair strategies face numerous challenges, mostly related to the development of highly biomimetic materials, non-invasive injectable solutions, and adequate degradation rates. These strategies often fail due to feeble mechanical properties, the inability to sustain cell adhesion, growth, and differentiation or by underestimating other players of cartilage degeneration, such as the installed pro-inflammatory microenvironment. The integration of nanomaterials (NMs) into 3D scaffolds, hydrogels and bioinks hold great potential in the improvement of key features of materials that are currently applied in cartilage tissue engineering strategies. NMs offer a high surface to volume ratio and their multiple applications can be explored to enhance cartilage mechanical properties, biocompatibility, cell differentiation, inflammation modulation, infection prevention and even to function as diagnostic tools or as stimuli-responsive cues in these 3D structures. In this review, we have critically reviewed the latest advances in the development of nanoenabled 3D matrices - enhanced by means of NMs - in the context of cartilage regeneration. We have provided a wide perspective of the synergistic effect of combining 3D strategies with NMs, with emphasis on the benefits brought by NMs in achieving functional and enhanced therapeutic outcomes. STATEMENT OF SIGNIFICANCE: Cartilage is one of the most challenging tissues to treat owing to its limited self-regeneration potential. Novel strategies using nanoenabled 3D matrices have emerged from the need to design more efficient solutions for cartilage repair, that take into consideration its unique mechanical properties and can direct specific cell behaviours. Here we aim to provide a comprehensive review on the synergistic effects of 3D matrices nanoenrichment in the context of cartilage regeneration, with emphasis on the heightening brought by nanomaterials in achieving functional and enhanced therapeutic outcomes. We anticipate this review to provide a wide perspective on the past years' research on the field, demonstrating the great potential of these approaches in the treatment and diagnosis of cartilage-related disorders.

Evaluating nanobiomaterial-induced DNA strand breaks using the alkaline comet assay

Due to their unique chemical and physical properties, nanobiomaterials (NBMs) are extensively studied for applications in medicine and drug delivery. Despite these exciting properties, their small sizes also make them susceptible to toxicity. Whilst nanomaterial immunotoxicity and cytotoxicity are studied in great depth, there is still limited data on their potential genotoxicity or ability to cause DNA damage. In the past years, new medical device regulations, which came into place in 2020, were developed, which require the assessment of long-term NBM exposure; therefore, in recent years, increased attention is being paid to genotoxicity screening of these materials. In this article, and through an interlaboratory comparison (ILC) study conducted within the Horizon 2020 REFINE project, we assess five different NBM formulations, each with different uses, namely, a bio-persistent gold nanoparticle (AuNP), an IR-780 dye-loaded liposome which is used in deep tissue imaging (LipImage™815), an unloaded PACA polymeric nanoparticle used as a drug delivery system (PACA), and two loaded PACA NBMs, i.e. the cabazitaxel drug-loaded PACA (CBZ-PACA) and the NR668 dye-loaded PACA (NR668 PACA) for their potential to cause DNA strand breaks using the alkaline comet assay and discuss the current state of genotoxicity testing for nanomaterials. We have found through our interlaboratory comparison that the alkaline comet assay can be suitably applied to the pre-clinical assessment of NBMs, as a reproducible and repeatable methodology for assessing NBM-induced DNA damage.

Delivering the power of nanomedicine to patients today

The situation of the COVID-19 pandemic reminds us that we permanently need high-value flexible solutions to urgent clinical needs including simplified diagnostic technologies suitable for use in the field and for delivering targeted therapeutics. From our perspective nanotechnology is revealed as a vital resource for this, as a generic platform of technical solutions to tackle complex medical challenges. It is towards this perspective and focusing on nanomedicine that we take issue with Prof Park's recent editorial published in the Journal of Controlled Release. Prof. Park argued that in the last 15 years nanomedicine failed to deliver the promised innovative clinical solutions to the patients (Park, K. The beginning of the end of the nanomedicine hype. Journal of Controlled Release, 2019; 305, 221-222 [1]. We, the ETPN (European Technology Platform on Nanomedicine) [2], respectfully disagree. In fact, the more than 50 formulations currently in the market, and the recent approval of 3 key nanomedicine products (e. g. Onpattro, Hensify and Vyxeos), have demonstrated that the nanomedicine field is concretely able to design products that overcome critical barriers in conventional medicine in a unique manner, but also to deliver within the cells new drug-free therapeutic effects by using pure physical modes of action, and therefore make a difference in patients lives. Furthermore, the >400 nanomedicine formulations currently in clinical trials are expecting to bring novel clinical solutions (e.g. platforms for nucleic acid delivery), alone or in combination with other key enabling technologies to the market, including biotechnologies, microfluidics, advanced materials, biomaterials, smart systems, photonics, robotics, textiles, Big Data and ICT (information & communication technologies) more generally. However, we agree with Prof. Park that " it is time to examine the sources of difficulty in clinical translation of nanomedicine and move forward ". But for reaching this goal, the investments to support clinical translation of promising nanomedicine formulations should increase, not decrease. As recently encouraged by EMA in its roadmap to 2025, we should create more unity through a common knowledge hub linking academia, industry, healthcare providers and hopefully policy makers to reduce the current fragmentation of the standardization and regulatory body landscape. We should also promote a strategy of cross-technology innovation, support nanomedicine development as a high value and low-cost solution to answer unmet medical needs and help the most promising innovative projects of the field to get better and faster to the clinic. This global vision is the one that the ETPN chose to encourage for the last fifteen years. All actions should be taken with a clear clinical view in mind, " without any fanfare", to focus "on what matters in real life", which is the patient and his/her quality of life. This ETPN overview of achievements in nanomedicine serves to reinforce our drive towards further expanding and growing the maturity of nanomedicine for global healthcare, accelerating the pace of transformation of its great potential into tangible medical breakthroughs.

Safe-by-Design of Glucan Nanoparticles: Size Matters When Assessing the Immunotoxicity

Glucan (from Alcaligenes faecalis) is a polymer composed of β-1,3-linked glucose residues, and it has been addressed in different medical fields, namely in nanotechnology, as a vaccine or a drug delivery system. However, due to their small size, nanomaterials may present new risks and uncertainties. Thus, this work aims to describe the production of glucan nanoparticles (NPs) with two different sizes, and to evaluate the influence of the NPs size on immunotoxicity. Results showed that, immediately after production, glucan NPs presented average sizes of 129.7 ± 2.5 and 355.4 ± 41.0 nm. Glucan NPs of 130 nm presented greater ability to decrease human peripheral blood mononuclear cells and macrophage viability and to induce reactive oxygen species production than glucan NPs of 355 nm. Both NP sizes caused hemolysis and induced a higher metabolic activity in lymphocytes, although the concentration required to observe such effect was lower for the 130 nm glucan NPs. Regarding pro-inflammatory cytokines, only the larger glucan NPs (355 nm) were able to induce the secretion of IL-6 and TNF-α, probably due to their recognition by dectin-1. This higher immunomodulatory effect of the larger NPs was also observed in its ability to stimulate the production of nitric oxide (NO) and IL-1β. On the contrary, a small amount of Glu 130 NPs inhibited NO production. In conclusion, on the safe-by-design of glucan NPs, the size of the particles should be an important critical quality attribute to guarantee the safety and effectiveness of the nanomedicine.

Rigor and reproducibility in polymer nanoparticle synthesis and characterization

Standardized process improvement methods and tools were used to enhance the rigor and reproducibility of diblock copolymer nanoparticle (NP) synthesis and characterization. Models linking design parameters with NP characteristics boosted process control for NP synthesis, which may improve translation and commercialization of NP research.

Novel modeling and process control approaches provide useful insights to improve rigor and reproducibility in polymer nanoparticle synthesis and characterization.