Nanomedicines - Tiny particles and big challenges

The second phase of tumor invasion driven by immune cells: A study on doxorubicin-loaded PLG nanoparticles

Poly(lactide-co-glycolide) (PLG) nanoparticles loaded with doxorubicin have reached phase-I clinical trials for treating advanced solid tumors. This study explores cell hitchhiking, where nanoparticles associate with blood cells and investigates the impact on pharmacokinetics and tumor migration. Previous findings highlighted the early post-injection phase dominated by nonspecific nanoparticle-cell interactions and burst release. In contrast, this study examines the subsequent phase of tumor invasion, emphasizing the role of immune cells, mostly neutrophils, in redistributing the carrier to the tumor site via blood cell hitchhiking. We provide a detailed investigation of nanoparticle extravasation kinetics and mechanisms, showing qualitative and quantitative evidence of increased nanoparticle association with immune cells over time. By 30 min post-injection, approximately 15 % of monocytes and 15-19 % of neutrophils tested positive for nanoparticles, with significant differences observed between ex vivo and in vivo experiments, and between healthy and tumor-bearing animals. This study underscores the ambiguous role of immune cell-mediated tumor targeting. While the total accumulation of the carrier rises, this fraction is partially trapped in immune cells without any chance to escape.

Revisiting nanomedicine design strategies for follow-on products: A model-informed approach to optimize performance

The field of nanomedicine is undergoing a seismic transformations with the rise of nanosimilars, reshaping the pharmaceutical landscape and expanding beyond traditional innovators and generic manufacturers. Nanodrugs are increasingly replacing conventional therapies, offering improved efficacy and safety, while the demand for follow-on products drives market diversification. However, the transition from preclinical to clinical stages presents challenges due to the complex biopharmaceutical behavior of nanodrugs. This review highlights the integration of Quality-by-Design (QbD), in vitro-in vivo correlations (IVIVCs), machine learning, and Model-Informed Drug Development (MIDD) as key strategies to address these complexities. Additionally, it discusses the role of high-throughput processes in the optimization of the nanodrug development pipelines. Covering generations of delivery systems from liposomes to RNA-loaded nanoparticles, this review underscores the evolving market dynamics driven by recent advances in nanomedicine.

Theoretical and Experimental Analyses of the Interfacial Mechanism of Dendrimer-Doxorubicin Complexes Formation

The work presents correlations between the physicochemical properties of the carrier and the active substance and optimization of the conditions for creating an active system based on PAMAM dendrimers and doxorubicin. The study monitored the influence of the ionized form of the doxorubicin molecule on the efficiency of complex formation. The deprotonated form of doxorubicin occurs under basic conditions in the pH range of 9.0-10.0. In the presence of doxorubicin, changes in the zeta potential of the complex concerning the initial system are observed. These changes result from electrostatic interactions between the drug molecules and external functional groups. Based on changes in the absorbance intensity of UV-vis spectra, the binding of the drug in the polymer structure is observed depending on the pH of the environment and the molar ratio. Optimal conditions for forming complexes occur under alkaline conditions. UV-vis, Fourier transform infrared spectroscopy, and circular dichroism spectroscopy confirmed the stability of the formed dendrimer-DOX complex. Molecular dynamics simulations were conducted to gain a deeper insight into the molecular mechanism of DOX adsorption on and within the G4.0 PAMAM dendrimers. It was observed that the protonation state of both the dendrimer and DOX significantly influences the adsorption stability. The system exhibited high stability at high pH values (∼9-10), with DOX molecules strongly adsorbed on the dendrimer surface and partially within its bulk. However, under lower pH conditions, a reduction in adsorption strength was observed, leading to the detachment of DOX clusters from the dendrimer structure.

Plant-derived exosome-like nanoparticles - from Laboratory to factory, a landscape of application, challenges and prospects

Recent decades have witnessed substantial interest in extracellular vesicles (EVs) due to their crucial role in intercellular communication across various biological processes. Among these, plant-derived exosome-like Nanoparticles (ELNs) have rapidly gained recognition as highly promising candidates. ELNs, characterized by diverse sources, cost-effective production, and straightforward isolation, present a viable option for preventing and treating numerous diseases. Furthermore, ELNs hold significant potential as carriers for natural or engineered drugs, enhancing their attractiveness and drawing considerable attention in science and medicine. However, translating ELNs into clinical applications poses several challenges. This study explores these challenges and offers critical insights into potential research directions. Additionally, it provides a forward-looking analysis of the industrial prospects for ELNs. With their broad applications and remarkable potential, ELNs stand at the forefront of biomedical innovation, poised to revolutionize disease management and drug delivery paradigms in the coming years.

Deciphering the Lipid-Random Copolymer Interactions and Encoding Their Properties to Design a Hybrid System

Lipid/copolymer colloidal systems are deemed hybrid materials with unique properties and functionalities. Their hybrid nature leads to complex interfacial phenomena, which have not been fully encoded yet, navigating their properties. Moving toward in-depth knowledge of such systems, a comprehensive investigation of them is imperative. In the present study, hybrid lipid/copolymer structures were fabricated and examined by a gamut of techniques, including dynamic light scattering, fluorescence spectroscopy, cryogenic transmission electron microscopy, microcalorimetry, and high-resolution ultrasound spectroscopy. The biomaterials that were mixed for this purpose at different ratios were 1,2-dioctadecanoyl-sn-glycero-3-phosphocholine and four different linear, statistical (random) amphiphilic copolymers, consisting of oligo(ethylene glycol) methyl ether methacrylate as the hydrophilic comonomer and lauryl methacrylate as the hydrophobic one. The colloidal dispersions were studied for lipid/copolymer interactions regarding their physicochemical, morphological, and biophysical behavior. Their membrane properties and interactions with serum proteins were also studied. The aforementioned techniques confirmed the hybrid nature of the systems and the location of the copolymer in the structure. More importantly, the random architecture of the copolymers, the hydrophobic-to-hydrophilic balance of the nanoplatforms, and the lipid-to-polymer ratio are highlighted as the main design-influencing factors. Elucidating the lipid/copolymer interactions would contribute to the translation of hybrid nanoparticle performance and, thus, their rational design for multiple applications, including drug delivery.

Modeling the Drug delivery Lifecycle of PLG Nanoparticles Using Intravital Microscopy

Polylactide-co-glycolide (PLG) nanoparticles hold immense promise for cancer therapy due to their enhanced efficacy and biodegradable matrix structure. Understanding their interactions with blood cells and subsequent biodistribution kinetics is crucial for optimizing their therapeutic potential. In this study, three doxorubicin-loaded PLG nanoparticle systems are synthesized and characterized, analyzing their size, zeta potential, morphology, and in vitro release behavior. Employing intravital microscopy in 4T1-tumor-bearing mice, real-time blood and tumor distribution kinetics are investigated. A mechanistic pharmacokinetic model is used to analyze biodistribution kinetics. Additionally, flow cytometry is utilized to identify cells involved in nanoparticle hitchhiking. Following intravenous injection, PLG nanoparticles exhibit an initial burst release (<1 min) and rapidly adsorb to blood cells (<5 min), hindering extravasation. Agglomeration leads to the clearance of one carrier species within 3 min. In stable dispersions, drug release rather than extravasation remains the dominant pathway for drug elimination from circulation. This comprehensive investigation provides valuable insights into the interplay between competing kinetics that influence the lifecycle of PLG nanoparticles post-injection. The findings advance the understanding of nanoparticle behavior and lay the foundation for improved cancer therapy strategies using nanoparticle-based drug delivery systems.

Recent advances in nano/micro systems for improved circulation stability, enhanced tumor targeting, penetration, and intracellular drug delivery: a review

In recent years, nanoparticles (NPs) have been extensively developed as drug carriers to overcome the limitations of cancer therapeutics. However, there are several biological barriers to nanomedicines, which include the lack of stability in circulation, limited target specificity, low penetration into tumors and insufficient cellular uptake, restricting the active targeting toward tumors of nanomedicines. To address these challenges, a variety of promising strategies were developed recently, as they can be designed to improve NP accumulation and penetration in tumor tissues, circulation stability, tumor targeting, and intracellular uptake. In this Review, we summarized nanomaterials developed in recent three years that could be utilized to improve drug delivery for cancer treatments.

Application of nZnO supported with nanoclay for improving shrimp immunity

This study discloses the nanoscale silicate platelet-supported nZnO (ZnONSP) applied as novel feed additives in aquaculture. The preparation of the nanohybrid (ZnO/NSP = 15/85, w/w) was characterized by UV-visible spectroscopy, powder X-ray diffraction and transmission electron microscope. The effects of ZnONSP on growth, zinc accumulation, stress response, immunity and resistance to Vibrio alginolyticus in white shrimp (Penaeus vannamei) were \demonstrated. To evaluate the safety of ZnONSP, shrimps (2.0 ± 0.3 g) were fed with ZnONSP containing diets (200, 400 and 800 mg/kg) for 56 days. Dietary ZnONSP did not affect the weight gain, specific growth rate, feed conversion ratio, survival rate, zinc accumulation, and the expression of heat shock protein 70 in tested shrimps. To examine the immunomodulatory effect of ZnONSP, shrimps (16.6 ± 2.4 g) were fed with the same experimental diets for 28 days. Dietary ZnONSP improved the immune responses of haemocyte in tested shrimps, including phagocytic rate, phagocytic index, respiratory burst, and phenoloxidase activity, and upregulated the expression of several genes, including lipopolysaccharide, β-1,3-glucan binding protein, peroxinectin, penaeidin 2/3/4, lysozyme, crustin, anti-lipopolysaccharide factor, superoxide dismutase, glutathione peroxidase, clotting protein and α-2-macroglobulin. In the challenge experiment, shrimps (17.2 ± 1.8 g) were fed with ZnONSP containing diets (400 and 800 mg/kg) for 7 days and then infected with Vibrio alginolyticus. Notably, white shrimps that received ZnONSP (800 mg/kg) showed significantly improved Vibrio resistance, with a survival rate of 71.4 % at the end of 7-day observation. In conclusion, this study discovers that ZnONSP is a new type of immunomodulatory supplement that are effective on enhancing innate cellular and humoral immunities, and disease resistance in white shrimp.

Feeding Next-Generation Nanomedicines to Europe: Regulatory and Quality Challenges

New and innovative nanomedicines have been developed and marketed over the past half-century, revolutionizing the prognosis of many human diseases. Although a univocal regulatory definition is not yet available worldwide, the term "nanomedicines" generally identifies medicinal products that use nanotechnology in their design or production. Due to the intrinsic high structural complexity of these products, the scientific and regulatory communities are reflecting on how to revise the regulatory framework to provide a more appropriate benefit/risk balance to authorize them on the market, considering the impact of their peculiar physicochemical features in the evaluation of efficacy and safety patterns. Herein, a critical perspective is provided on the current open issues regarding regulatory qualification and physicochemical characterization of nanosystems considering the current European regulatory framework on nanomedicine products. Practicable paths for improving their quality assurance and predicting their fate in vivo are also argued. Strengthening the multilevel alliance among academic institutions, industrial stakeholders, and regulatory authorities seems strategic to support innovation by standard approaches (e.g., qualification, characterization, risk assessment), and to expand current knowledge, also benefiting from the new opportunities offered by artificial intelligence and digitization in predictive modelling of the impact of nanomedicine characteristics on their fate in vivo.

Role of Particle Size in Translational Research of Nanomedicines for Successful Drug Delivery: Discrepancies and Inadequacies

Despite significant research progress in substantiating the therapeutic merits of nanomedicines and the emergence of sophisticated nanotechnologies, the translation of this knowledge into new therapeutic modalities has been sluggish, indicating the need for a more comprehensive understanding of how the unique physicochemical properties of nanoparticles affect their clinical applications. Particle size is a critical quality attribute that impacts the bio-fate of nanoparticles, yet precise knowledge of its effect remains elusive with discrepancies among literature reports. This review aims to address this scientific knowledge gap from a drug development perspective by highlighting potential inadequacies during the evaluation of particle size effects. We begin with a discussion on the major issues in particle size characterization along with the corresponding remedies. The influence of confounding factors on biological effects of particle size, including colloidal stability, polydispersity, and in vitro drug release, are addressed for establishing stronger in vitro-in vivo correlation. Particle size design and tailoring approaches for successful nanoparticulate drug delivery beyond parenteral administration are also illustrated. We believe a holistic understanding of the effect of particle size on bio-fate, combined with consistent nanoparticle manufacturing platforms and tailored characterization techniques, would expedite the translation of nanomedicines into clinical practice.

Purification processes of polymeric nanoparticles: How to improve their clinical translation?

Polymeric nanoparticles, as revolutionary nanomedicines, have offered a new class of diagnostic and therapeutic solutions for a multitude of diseases. With its immense potential, the world witnesses the new age of nanotechnology after the COVID-19 vaccines were developed based on nanotechnology. Even though there are countless benchtop research studies in the nanotechnology world, their integration into commercially available technologies is still restricted. The post-pandemic world demands a surge of research in the domain, which leaves us with the fundamental question: why is the clinical translation of therapeutic nanoparticles so restricted? Complications in nanomedicine purification, among other things, are to blame for the lack of transference. Polymeric nanoparticles, owing to their ease of manufacture, biocompatibility, and enhanced efficiency, are one of the more explored domains in organic-based nanomedicines. Purification of nanoparticles can be challenging and necessitates tailoring the available methods in accordance with the polymeric nanoparticle and impurities involved. Though a number of techniques have been described, there are no available guidelines that help in selecting the method to better suit our requirements. We encountered this difficulty while compiling articles for this review and looking for methods to purify polymeric nanoparticles. The currently accessible bibliography for purification techniques only provides approaches for a specific type of nanomaterial or sometimes even procedures for bulk materials, that are not fully relevant to nanoparticles. In our research, we tried to summarize the available purification techniques using the approach of A.F. Armington. We divided the purification systems into two major classes, namely: phase separation-based techniques (based on the physical differences between the phases) and matter exchange-based techniques (centered on physicochemical induced transfer of materials and compounds). The phase separation methods are based on either using nanoparticle size differences to retain them on a physical barrier (filtration techniques) or using their densities to segregate them (centrifugation techniques). The matter exchange separation methods rely on either transferring the molecules or impurities across a barrier using simple physicochemical phenomena, like the concentration gradients (dialysis method) or partition coefficients (extraction technique). After describing the methods in detail, we highlight their advantages and limitations, mainly focusing on preformed polymer-based nanoparticles. Tailoring a purification strategy takes into account the nanoparticle structure and its integrity, the method selected should be suited for preserving the integrity of the particles, in addition to conforming to the economical, material and productivity considerations. In the meantime, we advocate the use of a harmonized international regulatory framework to define the adequate physicochemical and biological characterization of nanomedicines. An appropriate purification strategy serves as the backbone to achieving desired characteristics, in addition to reducing variability. As a result, the present review aspires to serve as a comprehensive guide for researchers, who are new to the domain, as well as a synopsis of purification strategies and analytical characterization methods used in preclinical studies.

Business Risk Mitigation in the Development Process of New Monoclonal Antibody Drug Conjugates for Cancer Treatment

Recent developments aim to extend the cytotoxic effect and therapeutic window of mAbs by constructing antibody-drug conjugates (ADCs), in which the targeting moiety is the mAb that is linked to a highly toxic drug. According to a report from mid of last year, the global ADCs market accounted for USD 1387 million in 2016 and was worth USD 7.82 billion in 2022. It is estimated to increase in value to USD 13.15 billion by 2030. One of the critical points is the linkage of any substituent to the functional group of the mAb. Increasing the efficacy against cancer cells' highly cytotoxic molecules (warheads) are connected biologically. The connections are completed by different types of linkers, or there are efforts to add biopolymer-based nanoparticles, including chemotherapeutic agents. Recently, a combination of ADC technology and nanomedicine opened a new pathway. To fulfill the scientific knowledge for this complex development, our aim is to write an overview article that provides a basic introduction to ADC which describes the current and future opportunities in therapeutic areas and markets. Through this approach, we show which development directions are relevant both in terms of therapeutic area and market potential. Opportunities to reduce business risks are presented as new development principles.

Comparison of Compartmental and Non-Compartmental Analysis to Detect Biopharmaceutical Similarity of Intravenous Nanomaterial-Based Rifabutin Formulations

Pharmacometric analysis is often used to quantify the differences and similarities between formulation prototypes. In the regulatory framework, it plays a significant role in the evaluation of bioequivalence. While non-compartmental analysis provides an unbiased data evaluation, mechanistic compartmental models such as the physiologically-based nanocarrier biopharmaceutics model promise improved sensitivity and resolution for the underlying causes of inequivalence. In the present investigation, both techniques were applied to two nanomaterial-based formulations for intravenous injection, namely, albumin-stabilized rifabutin nanoparticles and rifabutin-loaded PLGA nanoparticles. The antibiotic rifabutin holds great potential for the treatment of severe and acute infections of patients co-infected with human immunodeficiency virus and tuberculosis. The formulations differ significantly in their formulation and material attributes, resulting in an altered biodistribution pattern as confirmed in a biodistribution study in rats. The albumin-stabilized delivery system further undergoes a dose-dependent change in particle size which leads to a small yet significant change in the in vivo performance. A second analysis was conducted comparing the dose fraction-scaled pharmacokinetic profiles of three dose levels of albumin-stabilized rifabutin nanoparticles. The dose strength affects both the nanomaterial-related absorption and biodistribution of the carrier as well as the drug-related distribution and elimination parameters, increasing the background noise and difficulty of detecting inequivalence. Depending on the pharmacokinetic parameter (e.g., AUC, C_max, Cl_obs), the relative (percentage) difference from the average observed using non-compartmental modeling ranged from 85% to 5.2%. A change in the formulation type (PLGA nanoparticles vs. albumin-stabilized rifabutin nanoparticles) resulted in a similar level of inequivalence as compared to a change in the dose strength. A mechanistic compartmental analysis using the physiologically-based nanocarrier biopharmaceutics model led to an average difference of 152.46% between the two formulation prototypes. Albumin-stabilized rifabutin nanoparticles tested at different dose levels led to a 128.30% difference, potentially due to changes in particle size. A comparison of different dose strengths of PLGA nanoparticles, on average, led to a 3.87% difference. This study impressively illustrates the superior sensitivity of mechanistic compartmental analysis when dealing with nanomedicines.

Macrophage-evading and tumor-specific apoptosis inducing nanoparticles for targeted cancer therapy

Extended circulation of anticancer nanodrugs in blood stream is essential for their clinical applications. However, administered nanoparticles are rapidly sequestered and cleared by cells of the mononuclear phagocyte system (MPS). In this study, we developed a biomimetic nanosystem that is able to efficiently escape MPS and target tumor tissues. The fabricated nanoparticles (TM-CQ/NPs) were coated with fibroblast cell membrane expressing tumor necrosis factor (TNF)-related apoptosis inducing ligand (TRAIL). Coating with this functionalized membrane reduced the endocytosis of nanoparticles by macrophages, but increased the nanoparticle uptake in tumor cells. Importantly, this membrane coating specifically induced tumor cell apoptosis via the interaction of TRAIL and its cognate death receptors. Meanwhile, the encapsulated chloroquine (CQ) further suppressed the uptake of nanoparticles by macrophages, and synergized with TRAIL to induce tumor cell apoptosis. The vigorous antitumor efficacy in two mice tumor models confirmed our nanosystem was an effective approach to address the MPS challenge for cancer therapy. Together, our TM-CQ/NPs nanosystem provides a feasible approach to precisely target tumor tissues and improve anticancer efficacy.

High-Throughput Counting and Sizing of Therapeutic Protein Aggregates in the Nanometer Size Range by Nano-Flow Cytometry

Protein aggregation is one of the greatest challenges in biopharmaceuticals as it could decrease therapeutic efficacy, induce immunogenicity, and reduce shelf life of protein drugs. However, there lacks high-throughput methods than can count and size protein aggregates in the nanometer size range, especially for those smaller than 100 nm. Employing a laboratory-built nano-flow cytometer (nFCM) that enables light scattering detection of single silica nanoparticles as small as 24 nm with sizing resolution and accuracy comparable to those of electron microscopy, here, we report a new benchmark to analyze single protein aggregates as small as 40 nm. With an analysis rate of up to 10,000 particles/min, the size distribution and particle concentration of nanometer protein aggregates can be acquired in 2-3 min. Employing heat-induced aggregation of bovine serum albumin (BSA) at high concentrations as the model system, effects of different categories of excipients, including sugars, polyols, salts, and amino acids on the inhibition of protein aggregation were investigated. Strikingly enough, as high as 10¹⁰ to 10¹² particles/mL of protein aggregates were observed in the size range of 40 to 200 nm for therapeutic proteins of human serum albumin injection, reconstituted recombinant human interieukin-2 solution, and human immunoglobulin injection. nFCM opens a new avenue to count and size nanometer protein aggregates, suggesting its future usability in the quality assessment and formulation promotion of therapeutic proteins.

Pharmaceutical Development of Nanostructured Vesicular Hydrogel Formulations of Rifampicin for Wound Healing

Chronic wounds exhibit elevated levels of inflammatory cytokines, resulting in the release of proteolytic enzymes which delay wound-healing processes. In recent years, rifampicin has gained significant attention in the treatment of chronic wounds due to an interesting combination of antibacterial and anti-inflammatory effects. Unfortunately, rifampicin is sensitive to hydrolysis and oxidation. As a result, no topical drug product for wound-healing applications has been approved. To address this medical need two nanostructured hydrogel formulations of rifampicin were developed. The liposomal vesicles were embedded into hydroxypropyl methylcellulose (HPMC) gel or a combination of hyaluronic acid and marine collagen. To protect rifampicin from degradation in aqueous environments, a freeze-drying method was developed. Before freeze-drying, two well-defined hydrogel preparations were obtained. After freeze-drying, the visual appearance, chemical stability, residual moisture content, and redispersion time of both preparations were within acceptable limits. However, the morphological characterization revealed an increase in the vesicle size for collagen-hyaluronic acid hydrogel. This was confirmed by subsequent release studies. Interactions of marine collagen with phosphatidylcholine were held responsible for this effect. The HPMC hydrogel formulation remained stable over 6 months of storage. Moving forward, this product fulfills all criteria to be evaluated in preclinical and clinical studies.

Longitudinal in vivo biodistribution of nano and micro sized hydroxyapatite particles implanted in a bone defect

Hydroxyapatite (HA) has been widely used as a bone substitute and more recently as a carrier for local delivery of bone targeted drugs. Majority of the approved HA based biomaterials and drug carriers comprise of micrometer sized particulate HA (mHA) or granules and can therefore only be used for extracellular drug release. This shortcoming could be overcome with the use of cell penetrating HA nanoparticles (nHA) but a major concern with the clinical use of nHA is the lack of data on its in vivo biodistribution after implantation. In this study, we aimed to study the in vivo biodistribution of locally implanted nHA in a clinically relevant tibial void in rats and compare it with mHA or a combination of mHA and nHA. To enable in vivo tracking, HA particles were first labelled with ¹⁴C-zoledronic acid (¹⁴C-ZA), known to have a high binding affinity to HA. The labelled particles were then implanted in the animals and the radioactivity in the proximal tibia and vital organs was detected at various time points (Day 1, 7 and 28) post-implantation using scintillation counting. The local distribution of the particles in the bone was studied with micro-CT. We found that majority (>99.9%) of the implanted HA particles, irrespective of the size, stayed locally at the implantation site even after 28 days and the findings were confirmed using micro-CT. Less than 0.1% radioactivity was observed in the kidney and the spleen at later time points of day 7 and 28. No pathological changes in any of the vital organs could be observed histologically. This is the first longitudinal in vivo HA biodistribution study showing that the local implantation of nHA particles in bone is safe and that nHA could potentially be used for localized drug delivery.

Plant-derived extracellular vesicles: Recent advancements and current challenges on their use for biomedical applications

Extracellular vesicles (EVs) represent a diverse class of lipid bilayer membrane vesicles released by both animal and plant cells. These ubiquitous vesicles are involved in intercellular communication and transport of various biological cargos, including proteins, lipids, and nucleic acids. In recent years, interest in plant-derived EVs has increased tremendously, as they serve as a scalable and sustainable alternative to EVs derived from mammalian sources. In vitro and in vivo findings have demonstrated that these plant-derived vesicles (PDVs) possess intrinsic therapeutic activities that can potentially treat diseases and improve human health. In addition, PDVs can also act as efficient and biocompatible drug carriers. While preclinical studies have shown promising results, there are still several challenges and knowledge gaps that have to be addressed for the successful translation of PDVs into clinical applications, especially in view of the lack of standardised protocols for material handling and PDV isolation from various plant sources. This review provides the readers with a quick overview of the current understanding and research on PDVs, critically analysing the current challenges and highlighting the immense potential of PDVs as a novel class of therapeutics to treat human diseases. It is expected that this work will guide scientists to address the knowledge gaps currently associated with PDVs and promote new advances in plant-based therapeutic solutions.

Amorphization and modified release of ibuprofen by post-synthetic and solvent-free loading into tailored silica aerogels

Promising active pharmaceutical ingredients (APIs) often exhibit poor aqueous solubility and thus a low bioavailability that substantially limits their pharmaceutical application. Hence, efficient formulations are required for an effective translation into highly efficient drug products. One strategy is the preservation of an amorphous state of the API within a carrier matrix, which leads to enhanced dissolution. In this work, mesoporous silica aerogels (SA) were utilized as a carrier matrix for the amorphization of the poorly water-soluble model drug ibuprofen. Loading of tailored SA was performed post-synthetically and solvent-free, either by co-milling or via the melting method. Thorough analyses of these processes demonstrated the influence of macrostructural changes during the drying and grinding process on the microstructural properties of the SA. Furthermore, interfacial SA-drug interaction properties were selectively tuned by attaching terminal hydrophilic amino- or hydrophobic methyl groups to the surface of the gel. We demonstrate that not only the chemical surface properties of the SA, but also formulation-related parameters, such as the carrier-to-drug ratio, as well as process-related parameters, such as the drug loading method, decisively influence the ibuprofen adsorption efficiency. In addition, the drug-loaded SA formulations exhibited a remarkable physical stability over a period of 6 months. Furthermore, the release behavior is shown to change considerably with different surface properties of the SA matrix. Hence, the reported results demonstrate that utilizing specifically processed and modified SA offers a compelling technique for enhancement of the bioavailability of poorly-water soluble APIs and a versatile adjustment of their release profile.

Grapefruit Extract-Mediated Fabrication of Photosensitive Aluminum Oxide Nanoparticle and Their Antioxidant and Anti-Inflammatory Potential

Aluminum oxide nanoparticles (Al₂O₃ NPs) were synthesized using a simple, eco-friendly green synthesis approach in an alkaline medium from the extract of grapefruit peel waste. The pre-synthesized, nano-crystalline Al₂O₃ NPs were characterized by using spectroscopic (UV-vis, FTIR, XRD, and EDX) and microscopic (SEM and TEM) techniques. The formed Al₂O₃ NPs exhibited a pronounced absorption peak at 278 nm in the UV-vis spectrum. The average particle size of the as-prepared Al₂O₃ NPs was evaluated to be 57.34 nm, and the atomic percentages of O and Al were found to be 54.58 and 45.54, respectively. The fabricated Al₂O₃ NPs were evaluated for antioxidant, anti-inflammatory, and immunomodulatory properties. The Al₂O₃ NPs showed strong antioxidant potential towards all the four tested assays. The anti-inflammatory and immunomodulatory potential of Al₂O₃ NPs was investigated by measuring the production of nitric oxide and superoxide anion (O₂^•-), as well as proinflammatory cytokines tumour necrosis factor (TNF-α, IL-6) and inhibition of nuclear factor kappa B (NF- κB). The results revealed that Al₂O₃ NPs inhibited the production of O₂^•- (99.4%) at 100 μg mL^-1 concentrations and intracellular NO^•- (55%), proinflammatory cytokines IL-6 (83.3%), and TNF-α (87.9%) at 50 μg mL^-1 concentrations, respectively. Additionally, the Al₂O₃ NPs inhibited 41.8% of nuclear factor kappa B at 20 μg mL^-1 concentrations. Overall, the outcomes of current research studies indicated that Al₂O₃ NPs possess anti-inflammatory and immunomodulatory properties and could be used to treat chronic and acute anti-inflammatory conditions.

Biopredictive tools for the development of injectable drug products

INTRODUCTION

Biopredictive release tests are commonly used in the evaluation of oral medicines. They support decision-making in formulation development and allow predictions of the expected in-vivo performances. So far, there is limited experience in the application of these methodologies to injectable drug products.

AREAS COVERED

Parenteral drug products cover a variety of dosage forms and administration sites including subcutaneous, intramuscular, and intravenous injections. In this area, developing biopredictive and biorelevant methodologies often confronts us with unique challenges and knowledge gaps. Here, we provide a formulation-centric approach and explain the key considerations and workflow when designing biopredictive assays. Also, we outline the key role of computational methods in achieving clinical relevance and put all considerations into context using liposomal nanomedicines as an example.

EXPERT OPINION

Biopredictive tools are the need of the hour to exploit the tremendous opportunities of injectable drug products. A growing number of biopharmaceuticals such as peptides, proteins, and nucleic acids require different strategies and a better understanding of the influences on drug absorption. Here, our design strategy must maintain the balance of robustness and complexity required for effective formulation development.

Bioimaging guided pharmaceutical evaluations of nanomedicines for clinical translations

Nanomedicines (NMs) have emerged as an efficient approach for developing novel treatment strategies against a variety of diseases. Over the past few decades, NM formulations have received great attention, and a large number of studies have been performed in this field. Despite this, only about 60 nano-formulations have received industrial acceptance and are currently available for clinical use. Their in vivo pharmaceutical behavior is considered one of the main challenges and hurdles for the effective clinical translation of NMs, because it is difficult to monitor the pharmaceutic fate of NMs in the biological environment using conventional pharmaceutical evaluations. In this context, non-invasive imaging modalities offer attractive solutions, providing the direct monitoring and quantification of the pharmacokinetic and pharmacodynamic behavior of labeled NMs in a real-time manner. Imaging evaluations have great potential for revealing the relationship between the physicochemical properties of NMs and their pharmaceutical profiles in living subjects. In this review, we introduced imaging techniques that can be used for in vivo NM evaluations. We also provided an overview of various studies on the influence of key parameters on the in vivo pharmaceutical behavior of NMs that had been visualized in a non-invasive and real-time manner.

Size-tuneable and immunocompatible polymer nanocarriers for drug delivery in pancreatic cancer

Nanocarriers have emerged as one of the most promising approaches for drug delivery. Although several nanomaterials have been approved for clinical use, the translation from lab to clinic remains challenging. However, by implementing rational design strategies and using relevant models for their validation, these challenges are being addressed. This work describes the design of novel immunocompatible polymer nanocarriers made of melanin-mimetic polydopamine and Pluronic F127 units. The nanocarrier preparation was conducted under mild conditions, using a highly reproducible method that was tuned to provide a range of particle sizes (<100 nm) without changing the composition of the carrier. A set of in vitro studies were conducted to provide a comprehensive assessment of the effect of carrier size (40, 60 and 100 nm) on immunocompatibility, viability and uptake into different pancreatic cancer cells varying in morphological and phenotypic characteristics. Pancreatic cancer is characterised by poor treatment efficacy and no improvement in patient survival in the last 40 years due to the complex biology of the solid tumour. High intra- and inter-tumoral heterogeneity and a dense tumour microenvironment limit diffusion and therapeutic response. The Pluronic-polydopamine nanocarriers were employed for the delivery of irinotecan active metabolite SN38, which is used in the treatment of pancreatic cancer. Increased antiproliferative effect was observed in all tested cell lines after administration of the drug encapsulated within the carrier, indicating the system's potential as a therapeutic agent for this hard-to-treat cancer.

Three-dimensional (3D) liver cell models - a tool for bridging the gap between animal studies and clinical trials when screening liver accumulation and toxicity of nanobiomaterials

Despite the exciting properties and wide-reaching applications of nanobiomaterials (NBMs) in human health and medicine, their translation from bench to bedside is slow, with a predominant issue being liver accumulation and toxicity following systemic administration. In vitro 2D cell-based assays and in vivo testing are the most popular and widely used methods for assessing liver toxicity at pre-clinical stages; however, these fall short in predicting toxicity for NBMs. Focusing on in vitro and in vivo assessment, the accurate prediction of human-specific hepatotoxicity is still a significant challenge to researchers. This review describes the relationship between NBMs and the liver, and the methods for assessing toxicity, focusing on the limitations they bring in the assessment of NBM hepatotoxicity as one of the reasons defining the poor translation for NBMs. We will then present some of the most recent advances towards the development of more biologically relevant in vitro liver methods based on tissue-mimetic 3D cell models and how these could facilitate the translation of NBMs going forward. Finally, we also discuss the low public acceptance and limited uptake of tissue-mimetic 3D models in pre-clinical assessment, despite the demonstrated technical and ethical advantages associated with them.

Fabrication and characterization of chitosan nanoparticles using the coffee-ring effect for photodynamic therapy

BACKGROUND AND OBJECTIVES

Biocompatible nanoparticles have been increasingly used in a variety of medical applications, including photodynamic therapy. Although the impact of synthesis parameters and purification methods is reported in previous studies, it is still challenging to produce a reliable protocol for the fabrication, purification, and characterization of nanoparticles in the 200-300 nm range that are highly monodisperse for biomedical applications.

STUDY DESIGN/MATERIALS AND METHODS

We investigated the synthesis of chitosan nanoparticles in the 200-300 nm range by evaluating the chitosan to sodium tripolyphosphate (TPP) mass ratio and acetic acid concentration of the chitosan solution. Chitosan nanoparticles were also crosslinked to rose bengal and incubated with human breast cancer cells (MCF-7) to test photodynamic activity using a green laser (λ = 532 nm, power = 90 mW).

RESULTS

We established a simple protocol to fabricate and purify biocompatible nanoparticles with the most frequent size occurring between 200 and 300 nm. This was achieved using a chitosan to TPP mass ratio of 5:1 in 1% v/v acetic acid at a pH of 5.5. The protocol involved the formation of nanoparticle coffee rings that showed the particle shape to be spherical in the first approximation. Photodynamic treatment with rose bengal-nanoparticles killed ~98% of cancer cells.

CONCLUSION

A simple protocol was established to prepare and purify spherical and biocompatible chitosan nanoparticles with a peak size of ~200 nm. These have remarkable antitumor activity when coupled with photodynamic treatment.

Nanomedicine Ex Machina: Between Model-Informed Development and Artificial Intelligence

Today, a growing number of computational aids and simulations are shaping model-informed drug development. Artificial intelligence, a family of self-learning algorithms, is only the latest emerging trend applied by academic researchers and the pharmaceutical industry. Nanomedicine successfully conquered several niche markets and offers a wide variety of innovative drug delivery strategies. Still, only a small number of patients benefit from these advanced treatments, and the number of data sources is very limited. As a consequence, “big data” approaches are not always feasible and smart combinations of human and artificial intelligence define the research landscape. These methodologies will potentially transform the future of nanomedicine and define new challenges and limitations of machine learning in their development. In our review, we present an overview of modeling and artificial intelligence applications in the development and manufacture of nanomedicines. Also, we elucidate the role of each method as a facilitator of breakthroughs and highlight important limitations.

Need for Expansion of Pharmacy Education Globally for the Growing Field of Nanomedicine

The emerging landscape of nanomedicine includes a wide variety of active pharmaceutical ingredients and drug formulations. Their design provides nanomedicines with unique features leading to improved pharmacokinetics and pharmacodynamics. They are manufactured using conventional or biotechnological manufacturing processes. Their physical characteristics are vastly different from traditional small-molecule drugs. Pharmacists are important members of the multi-disciplinary team of scientists involved in their development and clinical application. Consequently, their training should lead to an understanding of the complexities associated with the production and evaluation of nanomedicines. Therefore, student pharmacists, post-doctoral researchers, and trainees should be given more exposure to this rapidly evolving class of therapeutics. This commentary will provide an overview of nanomedicine education within the selection of pharmacy programs globally, discuss the current regulatory challenges, and describe different approaches to incorporate nanomedicine science in pharmacy programs around the world.

The Hitchhiker's Guide to Human Therapeutic Nanoparticle Development

Nanomedicine plays an essential role in developing new therapies through novel drug delivery systems, diagnostic and imaging systems, vaccine development, antibacterial tools, and high-throughput screening. One of the most promising drug delivery systems are nanoparticles, which can be designed with various compositions, sizes, shapes, and surface modifications. These nanosystems have improved therapeutic profiles, increased bioavailability, and reduced the toxicity of the product they carry. However, the clinical translation of nanomedicines requires a thorough understanding of their properties to avoid problems with the most questioned aspect of nanosystems: safety. The particular physicochemical properties of nano-drugs lead to the need for additional safety, quality, and efficacy testing. Consequently, challenges arise during the physicochemical characterization, the production process, in vitro characterization, in vivo characterization, and the clinical stages of development of these biopharmaceuticals. The lack of a specific regulatory framework for nanoformulations has caused significant gaps in the requirements needed to be successful during their approval, especially with tests that demonstrate their safety and efficacy. Researchers face many difficulties in establishing evidence to extrapolate results from one level of development to another, for example, from an in vitro demonstration phase to an in vivo demonstration phase. Additional guidance is required to cover the particularities of this type of product, as some challenges in the regulatory framework do not allow for an accurate assessment of NPs with sufficient evidence of clinical success. This work aims to identify current regulatory issues during the implementation of nanoparticle assays and describe the major challenges that researchers have faced when exposing a new formulation. We further reflect on the current regulatory standards required for the approval of these biopharmaceuticals and the requirements demanded by the regulatory agencies. Our work will provide helpful information to improve the success of nanomedicines by compiling the challenges described in the literature that support the development of this novel encapsulation system. We propose a step-by-step approach through the different stages of the development of nanoformulations, from their design to the clinical stage, exemplifying the different challenges and the measures taken by the regulatory agencies to respond to these challenges.

Nanoparticle-assisted, image-guided laser interstitial thermal therapy for cancer treatment

Laser interstitial thermal therapy (LITT) guided by magnetic resonance imaging (MRI) is a new treatment option for patients with brain and non-central nervous system (non-CNS) tumors. MRI guidance allows for precise placement of optical fiber in the tumor, while MR thermometry provides real-time monitoring and assessment of thermal doses during the procedure. Despite promising clinical results, LITT complications relating to brain tumor procedures, such as hemorrhage, edema, seizures, and thermal injury to nearby healthy tissues, remain a significant concern. To address these complications, nanoparticles offer unique prospects for precise interstitial hyperthermia applications that increase heat transport within the tumor while reducing thermal impacts on neighboring healthy tissues. Furthermore, nanoparticles permit the co-delivery of therapeutic compounds that not only synergize with LITT, but can also improve overall effectiveness and safety. In addition, efficient heat-generating nanoparticles with unique optical properties can enhance LITT treatments through improved real-time imaging and thermal sensing. This review will focus on (1) types of inorganic and organic nanoparticles for LITT; (2) in vitro, in silico, and ex vivo studies that investigate nanoparticles' effect on light-tissue interactions; and (3) the role of nanoparticle formulations in advancing clinically relevant image-guided technologies for LITT. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Implantable Materials and Surgical Technologies > Nanoscale Tools and Techniques in Surgery.

Toxic effects of nanomaterials for health applications: How automation can support a systematic review of the literature?

Systematic reviews of the scientific literature can be an important source of information supporting the daily work of the regulators in their decision making, particularly in areas of innovative technologies where the regulatory experience is still limited. Significant research activities in the field of nanotechnology resulted in a huge number of publications in the last decades. However, even if the published data can provide relevant information, scientific articles are often of diverse quality, and it is nearly impossible to manually process and evaluate such amount of data in a systematic manner. In this feasibility study, we investigated to what extent open-access automation tools can support a systematic review of toxic effects of nanomaterials for health applications reported in the scientific literature. In this study, we used a battery of available tools to perform the initial steps of a systematic review such as targeted searches, data curation and abstract screening. This work was complemented with an in-house developed tool that allowed us to extract specific sections of the articles such as the materials and methods part or the results section where we could perform subsequent text analysis. We ranked the articles according to quality criteria based on the reported nanomaterial characterisation and extracted most frequently described toxic effects induced by different types of nanomaterials. Even if further demonstration of the reliability and applicability of automation tools is necessary, this study demonstrated the potential to leverage information from the scientific literature by using automation systems in a tiered strategy.

Nanomedicine at the crossroads - A quick guide for IVIVC

For many years, nanomedicine is pushing the boundaries of drug delivery. When applying these novel therapeutics, safety considerations are not only a key concern when entering clinical trials but also an important decision point in product development. Standing at the crossroads, nanomedicine may be able to escape the niche markets and achieve wider acceptance by the pharmaceutical industry. While there is a new generation of drug delivery systems, the extracellular vesicles, standing on the starting line, unresolved issues and new challenges emerge from their translation from bench to bedside. Some key features of injectable nanomedicines contribute to the predictability of the pharmacological and toxicological effects. So far, only a few of the physicochemical attributes of nanomedicines can be justified by a direct mathematical relationship between the in vitro and the in vivo responses. To further develop extracellular vesicles as drug carriers, we have to learn from more than 40 years of clinical experience in liposomal delivery and pass on this knowledge to the next generation. Our quick guide discusses relationships between physicochemical characteristics and the in vivo response, commonly referred to as in vitro-in vivo correlation. Further, we highlight the key role of computational methods, lay open current knowledge gaps, and question the established design strategies. Has the recent progress improved the predictability of targeted delivery or do we need another change in perspective?

An Update to Dialysis-Based Drug Release Testing-Data Analysis and Validation Using the Pharma Test Dispersion Releaser

Currently, a wide variety of complex non-oral dosage forms are entering the global healthcare market. Although many assays have been described in recent research, harmonized procedures and standards for testing their in vitro performance remain widely unexplored. Among others, dialysis-based techniques such as the Pharma Test Dispersion Releaser are developed for testing the release of drugs from nanoparticles, liposomes, or extracellular vesicle preparations. Here, we provide advanced strategies and practical advice for the development and validation of dialysis-based techniques, including documentation, analysis, and interpretation of the raw data. For this purpose, key parameters of the release assay, including the hydrodynamics in the device at different stirring rates, the selectivity for particles and molecules, as well as the effect of excipients on drug permeation were investigated. At the highest stirring rate, a more than twofold increase in the membrane permeation rate (from 0.99 × 10⁻³ to 2.17 × 10⁻³ cm²/h) was observed. Additionally, we designed a novel computer model to identify important quality parameters of the dialysis experiment and to calculate error-corrected release profiles. Two hydrophilic creams of diclofenac, Voltaren^® Emulgel, and Olfen^® gel, were tested and provide first-hand evidence of the robustness of the assay in the presence of semisolid dosage forms.

Facts and Figures on Materials Science and Nanotechnology Progress and Investment

As the twenty-first century unfolds, nanotechnology is no longer just a buzzword in the field of materials science, but rather a tangible reality. This is evident from the surging number of commercial nanoproducts and their corresponding revenue generated in different industry sectors. However, it is important to recognize that sustainable growth of nanotechnology is heavily dependent on government funding and relevant national incentive programs. Consequently, proper analyses on publicly available nanotechnology data sets comprising information on the past two decades can be illuminating, facilitate development, and amend previous strategies as we move forward. Along these lines, classical statistics and machine learning (ML) allow processing large data sets to scrutinize patterns in materials science and nanotechnology research. Herein, we provide an analysis on nanotechnology progress and investment from an unbiased, computational vantage point and using orthogonal approaches. Our data reveal both well-established and surprising correlations in the nanotechnology field and its actors, including the interplay between the number of research institutes-industry, publications-patents, collaborative research, and top contributors to nanoproducts. Overall, data suggest that, supported by incentive programs set out by stakeholders (researchers, funding agencies, policy makers, and industry), nanotechnology could experience an exponential growth and become a centerpiece for economical welfare. Indeed, the recent success of COVID-19 vaccines is also likely to boost public trust in nanotechnology and its global impact over the coming years.

Polymer-Based Nanotherapeutics for Burn Wounds

Burn wounds are complex and intricate injuries that have become a common cause of trauma leading to significant mortality and morbidity every year. Dressings are applied to burn wounds with the aim of promoting wound healing, preventing burn infection and restoring skin function. The dressing protects the injury and contributes to recovery of dermal and epidermal tissues. Polymer-based nanotherapeutics are increasingly being exploited as burn wound dressings. Natural polymers such as cellulose, chitin, alginate, collagen, gelatin and synthetic polymers like poly (lactic-co-glycolic acid), polycaprolactone, polyethylene glycol, and polyvinyl alcohol are being obtained as nanofibers by nanotechnological approaches like electrospinning and have shown wound healing and re-epithelialization properties. Their biocompatibility, biodegradability, sound mechanical properties and unique structures provide optimal microenvironment for cell proliferation, differentiation, and migration contributing to burn wound healing. The polymeric nanofibers mimic collagen fibers present in extracellular matrix and their high porosity and surface area to volume ratio enable increased interaction and sustained release of therapeutics at the site of thermal injury. This review is an attempt to compile all recent advances in the use of polymer-based nanotherapeutics for burn wounds. The various natural and synthetic polymers used have been discussed comprehensively and approaches being employed have been reported. With immense research effort that is currently being invested in this field and development of proper characterization and regulatory framework, future progress in burn treatment is expected to occur. Moreover, appropriate preclinical and clinical research will provide evidence for the great potential that polymer-based nanotherapeutics hold in the management of burn wounds.

Mesalazine and inflammatory bowel disease - From well-established therapies to progress beyond the state of the art

Inflammatory bowel disease incidence has been constantly rising for the past few decades. Current therapies attempt to mitigate its symptoms since no cure is established. The most commonly prescribed drug for these patients is 5-aminosalicylic acid (5-ASA). Due to the low rate and seriousness of side effects compared to other therapies, 5-ASA is still largely prescribed in many stages of inflammatory bowel disease, including scenarios where evidence suggests low effectiveness. Although commercialized formulations have come a long way in improving pharmacokinetics, it is still necessary to design and develop novel delivery systems capable of increasing effectiveness at different stages of the disease. In particular, micro- and nano-sized particles might be the key to its success in Crohn's disease and in more serious disease stages. This review provides an overview on the clinical significance of 5-ASA formulations, its limitations, challenges, and the most recent micro- and nanoparticle delivery systems being designed for its controlled release. Emergent alternatives for 5-ASA are also discussed, as well as the future prospects for its application in inflammatory bowel disease therapies.

Design of experiments (DoE) to develop and to optimize nanoparticles as drug delivery systems

Nanotechnology has been widely applied to develop drug delivery systems to improve therapeutic performance. The effectiveness of these systems is intrinsically related to their physicochemical properties, so their biological responses are highly susceptible to factors such as the type and quantity of each material that is employed in their synthesis and to the method that is used to produce them. In this context, quality-oriented manufacturing of nanoparticles has been an important strategy to understand and to optimize the factors involved in their production. For this purpose, Design of Experiment (DoE) tools have been applied to obtain enough knowledge about the process and hence achieve high-quality products. This review aims to set up the bases to implement DoE as a strategy to improve the manufacture of nanocarriers and to discuss the main factors involved in the production of the most common nanocarriers employed in the pharmaceutical field.

In-air particle generation by on-chip electrohydrodynamics

Electrohydrodynamic atomization has been emerging as a powerful approach for respiratory treatment, including the generation and delivery of micro/nanoparticles as carriers for drugs and antigens. In this work, we present a new conceptual design in which two nozzles facilitate dual electrospray coexisting with ionic wind at chamfered tips by a direct current power source. Experimental results by a prototype have demonstrated the capability of simultaneously generating-and-delivering a stream of charged reduced particles. The concept can be beneficial to pulmonary nano-medicine delivery since the mist of nanoparticles is migrated without any restriction of either the collector or the assistance of external flow, but is pretty simple in designing and manufacturing devices.

Nanoparticles and Nanocrystals by Supercritical CO2-Assisted Techniques for Pharmaceutical Applications: A Review

Many active ingredients currently prescribed show limited therapeutic efficacy, mainly due to their dissolution rate inadequate to treat the pathology of interest. A large drug particle size creates an additional problem if a specific site of action in the human body has to be reached. For this reason, active ingredient size reduction using micronization/nanonization techniques is a valid approach to improve the efficacy of active compounds. Supercritical carbon-dioxide-assisted technologies enable the production of different morphologies of different sizes, including nanoparticles and nanocrystals, by modulating operating conditions. Supercritical fluid-based processes have numerous advantages over techniques conventionally employed to produce nanosized particles or crystals, such as reduced use of toxic solvents, which are completely removed from the final product, ensuring safety for patients. Active compounds can be processed alone by supercritical techniques, although polymeric carriers are often added as stabilizers, to control the drug release on the basis of the desired therapeutic effect, as well as to improve drug processability with the chosen technology. This updated review on the application of supercritical micronization/nanonization techniques in the pharmaceutical field aims at highlighting the most effective current results, operating conditions, advantages, and limitations, providing future perspectives.

Analysis of dendrimer-protein interactions and their implications on potential applications of dendrimers in nanomedicine

This work addresses how G5.5 PAMAM dendrimers form complexes with bovine serum albumin (BSA). Analytical techniques, such as UV-vis spectrophotometry, dynamic light scattering, electrophoretic mobility, quartz crystal microbalance with dissipation monitoring (QCM-D), circular dichroism (CD), and contact angle were used to analyze the properties of the dendrimers systems. The binding of protein to dendrimers can alter the structure, mobility, conformation and functional activity of the dendrimer. The results show that BSA interactions with G5.5 dendrimer carriers are driven both by electrostatic and hydrophobic forces. Dendrimer surface charge is reduced upon contact with the protein. The protein shell formed on the surface of the carrier is very stable as evidenced by the QCM-D measurements. On the other hand, the CD spectra indicates a change in the secondary structure of the protein. The size of the changes is significantly dependent on the ratio of protein to dendrimer. Understanding the mechanism of interaction of potential carriers with proteins is important for their internalization into the cell.

Research on the fate of polymeric nanoparticles in the process of the intestinal absorption based on model nanoparticles with various characteristics: size, surface charge and pro-hydrophobics

BACKGROUND

The use of drug nanocarriers to encapsulate drugs for oral administration may become an important strategy in addressing the challenging oral absorption of some drugs. In this study-with the premise of controlling single variables-we prepared model nanoparticles with different particle sizes, surface charges, and surface hydrophobicity/hydrophilicity. The two key stages of intestinal nanoparticles (NPs) absorption-the intestinal mucus layer penetration stage and the trans-intestinal epithelial cell stage-were decoupled and analyzed. The intestinal absorption of each group of model NPs was then investigated.

RESULTS

Differences in the behavioral trends of NPs in each stage of intestinal absorption were found to result from differences in particle properties. Small size, low-magnitude negative charge, and moderate hydrophilicity helped NPs pass through the small intestinal mucus layer more easily. Once through the mucus layer, an appropriate size, positive surface charge, and hydrophobic properties helped NPs complete the process of transintestinal epithelial cell transport.

CONCLUSIONS

To achieve high drug bioavailability, the basic properties of the delivery system must be suitable for overcoming the physiological barrier of the gastrointestinal tract.

A Journey of Nanomotors for Targeted Cancer Therapy: Principles, Challenges, and a Critical Review of the State-of-the-Art

A nanomotor is a miniaturized device that converts energy stored in the environment into mechanical motion. The last two decades have witnessed a surge of research interests in the biomedical applications of nanomotors, but little clinical translation. To accelerate this process, targeted cancer therapy is used as an example to describe a "survive, locate, operate, and terminate" (SLOT) mission of a nanomotor, where it must 1) survive in the unfriendly in vivo environment, 2) locate its target as well as be located by human operators, 3) carry out specific operations, and 4) terminate after the mission is completed. Along this journey, the challenges presented to a nanomotor, including to power, navigate, steer, target, release, control, image, and communicate are discussed, and how state-of-the-art nanomotors meet or fall short of these requirements is critically reviewed. These discussions are then condensed into a table for easy reference. In particular, it is argued that chemically powered nanomotors are intrinsically ill-positioned for targeted cancer therapy, while nanomotors powered by magnetic fields or ultrasound show more promises. Following this argument, a tentative nanomotor design is then presented in the end to conform to the SLOT guideline, and to inspire practical, functional nanorobots that are yet to come.

Predicting the environmental emissions arising from conventional and nanotechnology-related pharmaceutical drug products

Today, environmental pollution with pharmaceutical drugs and their metabolites poses a major threat to the aquatic ecosystems. Active substances such as fenofibrate, are processed to pharmaceutical drug formulations before they are degraded by the human body and released into the wastewater. Compared to the conventional product Lipidil® 200, the pharmaceutical product Lipidil 145 One® and Ecocaps take advantage of nanotechnology to improve uptake and bioavailability of the drug in humans. In the present approach, a combination of in vitro drug release studies and physiologically-based biopharmaceutics modeling was applied to calculate the emission of three formulations of fenofibrate (Lipidil® 200, Lipidil 145 One®, Ecocaps) into the environment. Special attention was paid to the metabolized and non-metabolized fractions and their individual toxicity, as well as to the emission of nanomaterials. The fish embryo toxicity test revealed a lower aquatic toxicity for the metabolite fenofibric acid and therefore an improved toxicity profile. When using the microparticle formulation Lipidil® 200, an amount of 126 mg of non-metabolized fenofibrate was emitted to the environment. Less than 0.05% of the particles were in the lower nanosize range. For the nanotechnology-related product Lipidil 145 One®, the total drug emission was reduced by 27.5% with a nanomaterial fraction of approximately 0.5%. In comparison, the formulation prototype Ecocaps reduced the emission of fenofibrate by 42.5% without any nanomaterials entering the environment. In a streamlined life cycle assessment, the lowered dose in combination with a lowered drug-to-metabolite ratio observed for Ecocaps led to a reduction of the full life cycle impacts of fenofibrate with a reduction of 18% reduction in the global warming potential, 61% in ecotoxicity, and 15% in human toxicity. The integrated environmental assessment framework highlights the outstanding potential of advanced modeling technologies to determine environmental impacts of pharmaceuticals during early drug development using preclinical in vitro data.

Interactions of Gold and Silver Nanoparticles with Bacterial Biofilms: Molecular Interactions behind Inhibition and Resistance

Many bacteria have the capability to form a three-dimensional, strongly adherent network called 'biofilm'. Biofilms provide adherence, resourcing nutrients and offer protection to bacterial cells. They are involved in pathogenesis, disease progression and resistance to almost all classical antibiotics. The need for new antimicrobial therapies has led to exploring applications of gold and silver nanoparticles against bacterial biofilms. These nanoparticles and their respective ions exert antimicrobial action by damaging the biofilm structure, biofilm components and hampering bacterial metabolism via various mechanisms. While exerting the antimicrobial activity, these nanoparticles approach the biofilm, penetrate it, migrate internally and interact with key components of biofilm such as polysaccharides, proteins, nucleic acids and lipids via electrostatic, hydrophobic, hydrogen-bonding, Van der Waals and ionic interactions. Few bacterial biofilms also show resistance to these nanoparticles through similar interactions. The nature of these interactions and overall antimicrobial effect depend on the physicochemical properties of biofilm and nanoparticles. Hence, study of these interactions and participating molecular players is of prime importance, with which one can modulate properties of nanoparticles to get maximal antibacterial effects against a wide spectrum of bacterial pathogens. This article provides a comprehensive review of research specifically directed to understand the molecular interactions of gold and silver nanoparticles with various bacterial biofilms.

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.

Extracellular vesicles in cardiovascular disease

Cardiovascular disease remains the leading cause of morbidity and mortality globally. Extracellular vesicles (EVs), a group of heterogeneous nanosized cell-derived vesicles, have attracted great interest as liquid biopsy material for biomarker discovery in a variety of diseases including cardiovascular disease. Because EVs inherit bioactive components from parent cells and are able to transfer their contents to recipient cells, EVs hold great promise as potential cell-free therapeutics and drug delivery systems. However, the development of EV-based diagnostics, therapeutics or drug delivery systems has been challenging due to the heterogenicity of EVs in biogenesis, size and cellular origin, the lack of standardized isolation and purification methods as well as the low production yield. In this review, we will provide an overview of the recent advances in EV-based biomarker discovery, highlight the potential usefulness of EVs and EV mimetics for therapeutic treatment and drug delivery in cardiovascular disease. In view of the fast development in this field, we will also discuss the challenges of current methodologies for isolation, purification and fabrication of EVs and potential alternatives.

An Elucidative Review to Analytically Sieve the Viability of Nanomedicine Market

The advent of the twenty-first century marked a paradigm shift in the healthcare sector with coming of automated, sensitive, targeted medicines and technologies having diagnostic, prophylactic and therapeutic effects. Nanomedicines also attained wide acclamation in their initial years, but the transformation from being the proof of concept to successfully marketed products seems very daunting. Although the reason for this may be attributed to slow but incremental character of many present-day technologies, the review asserts that there are other significant facets that may purvey a thorough explanation of this scenario. The article elaborately discusses the hurdles hindering clinical translation of nanomedicines including scale-up challenges, in vitro in vivo cascade of toxicology assays, along with unrefined manufacturing guidelines, inadequate regulatory approvals, competitive conventional market, etc., leading to hesitant investments by pharmaceutical giants. The paper also explores the economic viability of nanobiotechnology sector through an empirical investigation of the revenue data of various pharmaceutical industries manufacturing nano-based drugs, which indicates minor commercial importance of these medicines. We also laid down a comprehensive set of recommendations to smoothen the translational pathway of nanomedicines from an idea to reality, efface the consumer distrust and push boundaries for development and launching of safe, efficient and commercially successful products. Graphical abstract.