Microfluidic technologies for accelerating the clinical translation of nanoparticles

Intravitreal therapeutic nanoparticles for age-related macular degeneration: Design principles, progress and opportunities

Age-related macular degeneration (AMD) is a leading cause of vision loss in the elderly. The current standard treatment for AMD involves frequent intravitreal administrations of therapeutic agents. While effective, this approach presents challenges, including patient discomfort, inconvenience, and the risk of adverse complications. Nanoparticle-based intravitreal drug delivery platforms offer a promising solution to overcome these limitations. These platforms are engineered to target the retina specifically and control drug release, which enhances drug retention, improves drug concentration and bioavailability at the retinal site, and reduces the frequency of injections. This review aims to uncover the design principles guiding the development of highly effective nanoparticle-based intravitreal drug delivery platforms for AMD treatment. By gaining a deeper understanding of the physiology of ocular barriers and the physicochemical properties of nanoparticles, we establish a basis for designing intravitreal nanoparticles to optimize drug delivery and drug retention in the retina. Furthermore, we review recent nanoparticle-based intravitreal therapeutic strategies to highlight their potential in improving AMD treatment efficiency. Lastly, we address the challenges and opportunities in this field, providing insights into the future of nanoparticle-based drug delivery to improve therapeutic outcomes for AMD patients.

Immunological nanomaterials to combat cancer metastasis

Metastasis causes greater than 90% of cancer-associated deaths, presenting huge challenges for detection and efficient treatment of cancer due to its high heterogeneity and widespread dissemination to various organs. Therefore, it is imperative to combat cancer metastasis, which is the key to achieving complete cancer eradication. Immunotherapy as a systemic approach has shown promising potential to combat metastasis. However, current clinical immunotherapies are not effective for all patients or all types of cancer metastases owing to insufficient immune responses. In recent years, immunological nanomaterials with intrinsic immunogenicity or immunomodulatory agents with efficient loading have been shown to enhance immune responses to eliminate metastasis. In this review, we would like to summarize various types of immunological nanomaterials against metastasis. Moreover, this review will summarize a series of immunological nanomaterial-mediated immunotherapy strategies to combat metastasis, including immunogenic cell death, regulation of chemokines and cytokines, improving the immunosuppressive tumour microenvironment, activation of the STING pathway, enhancing cytotoxic natural killer cell activity, enhancing antigen presentation of dendritic cells, and enhancing chimeric antigen receptor T cell therapy. Furthermore, the synergistic anti-metastasis strategies based on the combinational use of immunotherapy and other therapeutic modalities will also be introduced. In addition, the nanomaterial-mediated imaging techniques (e.g., optical imaging, magnetic resonance imaging, computed tomography, photoacoustic imaging, surface-enhanced Raman scattering, radionuclide imaging, etc.) for detecting metastasis and monitoring anti-metastasis efficacy are also summarized. Finally, the current challenges and future prospects of immunological nanomaterial-based anti-metastasis are also elucidated with the intention to accelerate its clinical translation.

Toward the scale-up production of polymeric nanotherapeutics for cancer clinical trials

Nanotherapeutics have gained significant attention for the treatment of numerous cancers, primarily because they can accumulate in and/or selectively target tumors leading to improved pharmacodynamics of encapsulated drugs. The flexibility to engineer the nanotherapeutic characteristics including size, morphology, drug release profiles, and surface properties make nanotherapeutics a unique platform for cancer drug formulation. Polymeric nanotherapeutics including micelles and dendrimers represent a large number of formulation strategies developed over the last decade. However, compared to liposomes and lipid-based nanotherapeutics, polymeric nanotherapeutics have had limited clinical translation from the laboratory. One of the key limitations of polymeric nanotherapeutics formulations for clinical translation has been the reproducibility in preparing consistent and homogeneous large-scale batches. In this review, we describe polymeric nanotherapeutics and discuss the most common laboratory and scale-up formulation methods, specifically those proposed for clinical cancer therapies. We also provide an overview of the major challenges and opportunities for scaling polymeric nanotherapeutics to clinical-grade formulations. Finally, we will review the regulatory requirements and challenges in advancing nanotherapeutics to the clinic.

Kinetically Controlled Polyelectrolyte Complex Assembly of microRNA-Peptide Nanoparticles toward Treating Mesothelioma

Broad size distributions and poor long-term colloidal stability of microRNA-carrying nanoparticles, especially those formed by polyelectrolyte complexation, represent major hurdles in realizing their clinical translation. Herein, peptide design is used alongside optimized flash nanocomplexation (FNC) to produce uniform peptide-based miRNA particles of exceptional stability that display anticancer activity against mesothelioma in vitro and in vivo. Modulating the content and display of lysine-based charge from small intrinsically disordered peptides used to complex miRNA proves essential in achieving stable colloids. FNC facilitates kinetic isolation of the mechanistic steps involved in particle formation to allow the preparation of particles of discrete size in a highly reproducible, scalable, and continuous manner, facilitating pre-clinical studies. To the best of the authors knowledge, this work represents the first example of employing FNC to prepare polyelectrolyte complexes of miRNA and peptide. Encapsulation of these particles into an injectable hydrogel matrix allows for their localized in vivo delivery by syringe. A one-time injection of a gel containing particles composed of miRNA-215-5p and the peptide PKM1 limits tumor progression in a xenograft model of mesothelioma.

Rational Design of NIR-II Emitting Conjugated Polymer Derived Nanoparticles for Image-Guided Cancer Interventions

Due to the reduced absorption, light scattering, and tissue autofluorescence in the NIR-II (1000-1700 nm) region, significant efforts are underway to explore diverse material platforms for in vivo fluorescence imaging, particularly for cancer diagnostics and image-guided interventions. Of the reported imaging agents, nanoparticles derived from conjugated polymers (CPNs) offer unique advantages to alternative materials including biocompatibility, remarkable absorption cross-sections, exceptional photostability, and tunable emission behavior independent of cell labeling functionalities. Herein, the current state of NIR-II emitting CPNs are summarized and structure-function-property relationships are highlighted that can be used to elevate the performance of next-generation CPNs. Methods for particle processing and incorporating cancer targeting modalities are discussed, as well as detailed characterization methods to improve interlaboratory comparisons of novel materials. Contemporary methods to specifically apply CPNs for cancer diagnostics and therapies are then highlighted. This review not only summarizes the current state of the field, but offers future directions and provides clarity to the advantages of CPNs over other classes of imaging agents.

Tau- and α-synuclein-targeted gold nanoparticles: applications, opportunities, and future outlooks in the diagnosis and therapy of neurodegenerative diseases

The use of nanomaterials in medicine offers multiple opportunities to address neurodegenerative disorders such as Alzheimer's and Parkinson's disease. These diseases are a significant burden for society and the health system, affecting millions of people worldwide without sensitive and selective diagnostic methodologies or effective treatments to stop their progression. In this sense, the use of gold nanoparticles is a promising tool due to their unique properties at the nanometric level. They can be functionalized with specific molecules to selectively target pathological proteins such as Tau and α-synuclein for Alzheimer's and Parkinson's disease, respectively. Additionally, these proteins are used as diagnostic biomarkers, wherein gold nanoparticles play a key role in enhancing their signal, even at the low concentrations present in biological samples such as blood or cerebrospinal fluid, thus enabling an early and accurate diagnosis. On the other hand, gold nanoparticles act as drug delivery platforms, bringing therapeutic agents directly into the brain, improving treatment efficiency and precision, and reducing side effects in healthy tissues. However, despite the exciting potential of gold nanoparticles, it is crucial to address the challenges and issues associated with their use in the medical field before they can be widely applied in clinical settings. It is critical to ensure the safety and biocompatibility of these nanomaterials in the context of the central nervous system. Therefore, rigorous preclinical and clinical studies are needed to assess the efficacy and feasibility of these strategies in patients. Since there is scarce and sometimes contradictory literature about their use in this context, the main aim of this review is to discuss and analyze the current state-of-the-art of gold nanoparticles in relation to delivery, diagnosis, and therapy for Alzheimer's and Parkinson's disease, as well as recent research about their use in preclinical, clinical, and emerging research areas.

Frequency dependence of nanorod self-alignment using microfluidic methods

Dielectrophoresis is a potential candidate for aligning nanorods on electrodes, in which the interplay between electric fields and microfluidics is critically associated with its yield. Despite much of previous work on dielectrophoresis, the impact of frequency modulation on dielectrophoresis-driven nanorod self-assembly is insufficiently understood. In this work, we systematically explore the frequency dependence of the self-alignment of silicon nanorod using a microfluidic channel. We vary the frequency from 1kHz to 1000 kHz and analyze the resulting alignments in conjunction with numerical analysis. Our experiment reveals an optimal alignment yield at approximately 100 kHz, followed by a decrease in alignment efficiency. The nanorod self-alignments are influenced by multiple consequences, including the trapping effect, induced electrical double layer, electrohydrodynamic flow, and particle detachment. This study provides insights into the impact of frequency modulation of electric fields on the alignment of silicon nanorods using dielectrophoresis, broadening its use in various future nanotechnology applications.

A Scalable Microfluidic Platform for Nanoparticle Formulation: For Exploratory- and Industrial-Level Scales

Nanoparticle synthesis on microfluidic platforms provides excellent reproducibility and control over bulk synthesis. While there have been plenty of platforms for producing nanoparticles (NPs) with controlled physicochemical properties, such platforms often operate in a narrow range of predefined flow rates. The flow rate limitation restricts either up-scalability for industrial production or down-scalability for exploratory research use. Here, we present a universal flow rate platform that operates over a wide range of flow rates (0.1-75 mL/min) for small-scale exploratory research and industrial-level synthesis of NPs without compromising the mixing capabilities. The wide range of flow rate is obtained by using a coaxial flow with a triangular microstructure to create a vortex regardless of the flow regime (Reynolds number). The chip synthesizes several types of NPs for gene and protein delivery, including polyplex, lipid NPs, and solid polymer NPs via self-assembly and precipitation, and successfully expresses GFP plasmid DNA in human T cells.

Advances in lipid nanoparticle mRNA therapeutics beyond COVID-19 vaccines

The remarkable success of two lipid nanoparticle-mRNA vaccines against coronavirus disease (COVID-19) has placed the therapeutic and prophylactic potential of messenger RNA (mRNA) in the spotlight. It has also drawn attention to the indispensable role of lipid nanoparticles in enabling the effects of this nucleic acid. To date, lipid nanoparticles are the most clinically advanced non-viral platforms for mRNA delivery. This is thanks to their favorable safety profile and efficiency in protecting the nucleic acid from degradation and allowing its cellular uptake and cytoplasmic release upon endosomal escape. Moreover, the development of lipid nanoparticle-mRNA therapeutics was already a very active area of research even before the COVID-19 pandemic, which has likely only begun to bear its fruits. In this Review, we first discuss key aspects of the development of lipid nanoparticles as mRNA carriers. We then highlight promising preclinical and clinical studies involving lipid nanoparticle-mRNA formulations against infectious diseases and cancer, and to enable protein replacement or supplementation and genome editing. Finally, we elaborate on the challenges in advancing lipid nanoparticle-mRNA technology to widespread therapeutic use.

Microfluidic synthesis of lipid-based nanoparticles for drug delivery: recent advances and opportunities

Microfluidic technologies are revolutionizing the synthesis of nanoscale lipid particles and enabling new opportunities for the production of lipid-based nanomedicines. By harnessing the benefits of microfluidics for controlling diffusive and advective transport within microfabricated flow cells, microfluidic platforms enable unique capabilities for lipid nanoparticle synthesis with precise and tunable control over nanoparticle properties. Here we present an assessment of the current state of microfluidic technologies for lipid-based nanoparticle and nanomedicine production. Microfluidic techniques are discussed in the context of conventional production methods, with an emphasis on the capabilities of microfluidic systems for controlling nanoparticle size and size distribution. Challenges and opportunities associated with the scaling of manufacturing throughput are discussed, together with an overview of emerging microfluidic methods for lipid nanomedicine post-processing. The impact of additive manufacturing on current and future microfluidic platforms is also considered.

Progress and challenges in the translation of cancer nanomedicines

With the booming development of nanotechnology, nanomedicines have made considerable progress in the pharmaceutical field. However, the number of nanodrugs approved for clinical treatment is very limited. The main obstacles stem from the complexity of nanomedicine composition, tumor heterogeneity, complexity and incomplete understanding of nanotumor interactions, uncontrollable scaling, high production costs, and uncertainty of regulations and standards. This review article described the current stage of nanomedicines and highlighted the challenges, strategies, and opportunities for clinical translation of nanomedicines.

Advanced optical imaging for the rational design of nanomedicines

Despite the enormous potential of nanomedicines to shape the future of medicine, their clinical translation remains suboptimal. Translational challenges are present in every step of the development pipeline, from a lack of understanding of patient heterogeneity to insufficient insights on nanoparticle properties and their impact on material-cell interactions. Here, we discuss how the adoption of advanced optical microscopy techniques, such as super-resolution optical microscopies, correlative techniques, and high-content modalities, could aid the rational design of nanocarriers, by characterizing the cell, the nanomaterial, and their interaction with unprecedented spatial and/or temporal detail. In this nanomedicine arena, we will discuss how the implementation of these techniques, with their versatility and specificity, can yield high volumes of multi-parametric data; and how machine learning can aid the rapid advances in microscopy: from image acquisition to data interpretation.

Effectiveness In Vivo and In Vitro of Polymeric Nanoparticles as a Drug Release System in the Treatment of Leishmaniasis

Leishmaniasis is a neglected disease caused by the parasite of the genus Leishmania. Current treatment regimens are obsolete and cause several side effects, promoting poor patient compliance, in addition to the vast majority already having the potential for resistance. Therefore, polymeric nanoparticles emerge as one of the viable alternatives to overcome existing limitations, through passive or active vectorization. This review aims to summarize the latest studies of polymeric nanoparticles as an alternative treatment for leishmaniasis. In the first section, the main pharmacokinetic and pharmacodynamic challenges of current drugs are reported. The second section details how nanoparticles with and without functionalization are efficient in the treatment of leishmaniasis, discussing the characteristics of the polymer in the formulation. In this way, polymeric nanoparticles can improve the physicochemical properties of leishmanicidal drugs, improving solubility and stability, as well as improve the release of these drugs, directly or indirectly reaching monocytes/macrophages. 64.28% drugs were focused on the treatment of visceral leishmaniasis, and 28.57% on cutaneous leishmaniasis. The most chosen polymers in the literature are chitosan (35.71%) and PLGA (35.71%), the others represented 14.30% drugs, with all able to manage the drug release and increase the in vitro and/or in vivo efficacy of the original molecule. However, there are several barriers for these nanoformulations to cross laboratory research and is necessary more in-depth studies about the metabolites and degradation pathways of the polymers used in the formulations and plasma proteomics studies.

Ethoxy acetalated dextran nanoparticles for drug delivery: A comparative study of formulation methods

Dextran-based polymers, such as ethoxy acetalated dextran (Ace-DEX), are increasingly becoming the focus of research as they offer great potential for the development of polymer-based nanoparticles as drug delivery vehicles. Their major advantages are the facile synthesis, straightforward particle preparation and the pH-dependent degradation of the particles that can be fine-tuned by the degree of acetalation of the polymer. In this study we have shown that Ace-DEX can not only compete against the commonly used and FDA-approved polymer poly(lactic-co-glycolic acid) (PLGA), but even has the potential to outperform it in its encapsulation properties, e.g., for the herein used anti-inflammatory leukotriene biosynthesis inhibitor BRP-187. We used three different methods (microfluidics, batch nanoprecipitation and emulsion solvent evaporation) for the preparation of BRP-187-loaded Ace-DEX nanoparticles to investigate the influence of the formulation technique on the physicochemical properties of the particles. Finally, we evaluated which production method offers the greatest potential for achieving the demands for a successful translation from research into pharmaceutical production by fulfilling the basic requirements, such as reaching a high loading capacity of the particles and excellent reproducibility while being simple and affordable.

Microfluidic manufacturing of tioconazole loaded keratin nanocarriers: Development and optimization by design of experiments

Fungal infections of the skin, nails, and hair are a common health concern affecting a significant proportion of the population worldwide. The current treatment options include topical and systematic agents which have low permeability and prolonged treatment period, respectively. Consequently, there is a growing need for a permeable, effective, and safe treatment. Keratin nanoparticles are a promising nanoformulation that can improve antifungal agent penetration, providing sustainable targeted drug delivery. In this study, keratin nanoparticles were prepared using a custom-made 3D-printed microfluidic chip and the manufacturing process was optimized using the design of experiments (DoE) approach. The total flow rate (TFR), flow rate ratio (FRR), and keratin concentration were found to be the most influential factors of the size and polydispersity index (PDI) of the nanoparticles. The crosslinking procedure by means of tannic acid as safe and biocompatible compound was also optimized. Keratin nanoparticles loaded with a different amount of tioconazole showed a size lower than 200 nm, a PDI lower than 0.2 and an encapsulation efficiency of 91 ± 1.9 %. Due to their sustained drug release, the formulations showed acceptable in vitro biocompatibility. Furthermore, a significant inhibitory effect compared to the free drug against Microsporum canis.

Microfluidic synthesis of nanomaterials for biomedical applications

The field of nanomaterials has progressed dramatically over the past decades with important contributions to the biomedical area. The physicochemical properties of nanomaterials, such as the size and structure, can be controlled through manipulation of mass and heat transfer conditions during synthesis. In particular, microfluidic systems with rapid mixing and precise fluid control are ideal platforms for creating appropriate synthesis conditions. One notable example of microfluidics-based synthesis is the development of lipid nanoparticle (LNP)-based mRNA vaccines with accelerated clinical translation and robust efficacy during the COVID-19 pandemic. In addition to LNPs, microfluidic systems have been adopted for the controlled synthesis of a broad range of nanomaterials. In this review, we introduce the fundamental principles of microfluidic technologies including flow field- and multiple field-based methods for fabricating nanoparticles, and discuss their applications in the biomedical field. We conclude this review by outlining several major challenges and future directions in the implementation of microfluidic synthesis of nanomaterials.

Kinetically Controlled Nucleation Enabled by Tunable Microfluidic Mixing for the Synthesis of Dendritic Au@Pt Core/Shell Nanomaterials

The nucleation stage plays a decisive role in determining nanocrystal morphology and properties; hence, the ability to regulate nucleation is critical for achieving high-level control. Herein, glass microfluidic chips with S-shaped mixing units are designed for the synthesis of Au@Pt core/shell materials. The use of hydrodynamics to tune the nucleation kinetics is explored by varying the number of mixing units. Dendritic Au@Pt core/shell nanomaterials are controllably synthesized and a formation mechanism is proposed. As-synthesized Au@Pt exhibited excellent ethanol oxidation activity under alkaline conditions (8.4 times that of commercial Pt/C). This approach is also successfully applied to the synthesize of Au@Pd core/shell nanomaterials, thus demonstrating its generality.

Lipid-Based Nanoparticles for Drug/Gene Delivery: An Overview of the Production Techniques and Difficulties Encountered in Their Industrial Development

Over the past decade, the therapeutic potential of nanomaterials as novel drug delivery systems complementing conventional pharmacology has been widely acknowledged. Among these nanomaterials, lipid-based nanoparticles (LNPs) have shown remarkable pharmacological performance and promising therapeutic outcomes, thus gaining substantial interest in preclinical and clinical research. In this review, we introduce the main types of LNPs used in drug formulations such as liposomes, nanoemulsions, solid lipid nanoparticles, nanostructured lipid carriers, and lipid polymer hybrid nanoparticles, focusing on their main physicochemical properties and therapeutic potential. We discuss computational studies and modeling techniques to enhance the understanding of how LNPs interact with therapeutic cargo and to predict the potential effectiveness of such interactions in therapeutic applications. We also analyze the benefits and drawbacks of various LNP production techniques such as nanoprecipitation, emulsification, evaporation, thin film hydration, microfluidic-based methods, and an impingement jet mixer. Additionally, we discuss the major challenges associated with industrial development, including stability and sterilization, storage, regulatory compliance, reproducibility, and quality control. Overcoming these challenges and facilitating regulatory compliance represent the key steps toward LNP's successful commercialization and translation into clinical settings.

Protein and Peptide-Based Nanotechnology for Enhancing Stability, Bioactivity, and Delivery of Anthocyanins

Anthocyanin, a unique natural polyphenol, is abundant in plants and widely utilized in biomedicine, cosmetics, and the food industry due to its excellent antioxidant, anticancer, antiaging, antimicrobial, and anti-inflammatory properties. However, the degradation of anthocyanin in an extreme environment, such as alkali pH, high temperatures, and metal ions, limits its physiochemical stabilities and bioavailabilities. Encapsulation and combining anthocyanin with biomaterials could efficiently stabilize anthocyanin for protection. Promisingly, natural or artificially designed proteins and peptides with favorable stabilities, excellent biocapacity, and wide sources are potential candidates to stabilize anthocyanin. This review focuses on recent progress, strategies, and perspectives on protein and peptide for anthocyanin functionalization and delivery, i.e., formulation technologies, physicochemical stability enhancement, cellular uptake, bioavailabilities, and biological activities development. Interestingly, due to the simplicity and diversity of peptide structure, the interaction mechanisms between peptide and anthocyanin could be illustrated. This work sheds light on the mechanism of protein/peptide-anthocyanin nanoparticle construction and expands on potential applications of anthocyanin in nutrition and biomedicine.

Effects of Microfluidic Shear on the Plasmid DNA Structure: Implications for Polymeric Gene Delivery Vectors

Microfluidic manufacturing of advanced gene delivery vectors necessitates consideration of the effects of microfluidic shear forces on the structural integrity of plasmid DNA (pDNA). In this paper, we expose pDNA to variable shear forces in a two-phase, gas-liquid microfluidic reactor and apply gel electrophoresis to analyze the products of on-chip shear-induced degradation. The effects of shear rate, solvent environment, pDNA size, and copolymer complexation on shear-induced degradation are investigated. We find that small naked pDNA (pUC18, 2.7 kb) exhibits shear rate-dependent shear degradation in the microfluidic channels in a mixed organic solvent (dioxane/water/acetic acid; 90/10/<0.1 w/w/w), with the extents of both supercoil isoform relaxation and complete fragmentation increasing as the maximum shear rates increase from 4 × 105 to 2 × 106 s-1. However, over the same range of shear rates, the same pDNA sample shows no evidence of microfluidic shear-induced degradation in a pure aqueous environment. Quiescent control experiments in the same mixed organic solvent prove that a combination of solvent and shear forces is involved in the observed shear-induced degradation. Furthermore, we show that shear degradation effects in mixed organic solvents can be significantly attenuated by complexation of pDNA with the block copolymer polycaprolactone-block-poly(2-vinylpyridine) prior to exposure to microfluidic shear. Finally, we demonstrate that medium (pDSK519, 8.1 kb) and large (pRK290, 20 kb) naked pDNA are more sensitive to shear-induced microfluidic degradation in the mixed organic solvent environment than small pDNA, with both plasmids showing complete fragmentation even at the lowest shear rate, although we found no evidence of shear-induced damage in water for the largest investigated naked pDNA even at the highest flow rate. The resulting understanding of the interplay of the solvent and shear effects during microfluidic processing should inform microfluidic manufacturing routes to new gene therapy formulations.

Throughput-scalable manufacturing of SARS-CoV-2 mRNA lipid nanoparticle vaccines

Lipid nanoparticles (LNPs) are a potent delivery technology that have made it possible for the recent clinical breakthroughs in mRNA therapeutics and vaccines. A key challenge to the broader implementation of mRNA therapeutics and vaccines is the development of technology to produce precisely defined LNP formulations, with throughput that can scale from discovery to commercial manufacturing and meet the stringent manufacturing standards of the pharmaceutical industry. To address these challenges, we have developed a microfluidic chip that incorporates 1×, 10×, or 256× LNP-generating units that achieve scalable production rates of up to 17 L/h of precisely defined LNPs. Using these chips, we demonstrate that LNP physical properties and potency in vivo are unchanged as throughput is scaled. Our chips are fabricated out of silicon and glass substrates, which have excellent solvent compatibility, compatibility with pharmaceutical manufacturing, and can be fully reset and reused. SARS-CoV-2 mRNA-LNP vaccines formulated by our chips triggered potent antibody responses in a preclinical study. These results demonstrate the feasibility of directly translating microfluidic-generated LNPs to the scale necessary for commercial production.

Exploring the Microfluidic Production of Biomimetic Hybrid Nanoparticles and Their Pharmaceutical Applications

Nanomedicines have made remarkable advances in recent years, addressing the limitations of traditional therapy and treatment methods. Due to their improved drug solubility, stability, precise delivery, and ability to target specific sites, nanoparticle-based drug delivery systems have emerged as highly promising solutions. The successful interaction of nanoparticles with biological systems, on the other hand, is dependent on their intentional surface engineering. As a result, biomimetic nanoparticles have been developed as novel drug carriers. In-depth knowledge of various biomimetic nanoparticles, their applications, and the methods used for their formulation, with emphasis on the microfluidic production technique, is provided in this review. Microfluidics has emerged as one of the most promising approaches for precise control, high reproducibility, scalability, waste reduction, and faster production times in the preparation of biomimetic nanoparticles. Significant advancements in personalized medicine can be achieved by harnessing the benefits of biomimetic nanoparticles and leveraging microfluidic technology, offering enhanced functionality and biocompatibility.

EGFR-targeted semiconducting polymer nanoparticles for photoacoustic imaging

Semiconducting polymer nanoparticles (SPN), formulated from organic semiconducting polymers and lipids, show promise as exogenous contrast agents for photoacoustic imaging (PAI). To fully realise the potential of this class of nanoparticles for imaging and therapeutic applications, a broad range of active targeting strategies, where ligands specific to receptors on the target cells are displayed on the SPN surface, are urgently needed. In addition, effective strategies for quantifying the level of surface modification are also needed to support development of ligand-targeted SPN. In this paper, we have developed methods to prepare SPN bearing peptides targeted to Epidermal Growth Factor Receptors (EGFR), which are overexpressed at the surface of a wide variety of cancer cell types. In addition to fully characterising these targeted nanoparticles by standard methods (UV-visible, photoacoustic absorption, dynamic light scattering, zeta potential and SEM), we have developed a powerful new NMR method to determine the degree of conjugation and the number of targeting peptides attached to the SPN. Preliminary in vitro experiments with the colorectal cancer cell line LIM1215 indicated that the EGFR-targeting peptide conjugated SPN were either ineffective in delivering the SPN to the cells, or that the targeting peptide itself destabilised the formulation. This in reinforces the need for effective characterisation techniques to measure the surface accessibility of targeting ligands attached to nanoparticles.

Controlled Interfacial Polymer Self-Assembly Coordinates Ultrahigh Drug Loading and Zero-Order Release in Particles Prepared under Continuous Flow

Microparticles are successfully engineered through controlled interfacial self-assembly of polymers to harmonize ultrahigh drug loading with zero-order release of protein payloads. To address their poor miscibility with carrier materials, protein molecules are transformed into nanoparticles, whose surfaces are covered with polymer molecules. This polymer layer hinders the transfer of cargo nanoparticles from oil to water, achieving superior encapsulation efficiency (up to 99.9%). To control payload release, the polymer density at the oil-water interface is enhanced, forming a compact shell for microparticles. The resultant microparticles can harvest up to 49.9% mass fraction of proteins with zero-order release kinetics in vivo, enabling an efficient glycemic control in type 1 diabetes. Moreover, the precise control of engineering process offered through continuous flow results in high batch-to-batch reproducibility and, ultimately, excellent scale-up feasibility.

Self-Driving Underwater "Aerofluidics"

Here, the concept of "aerofluidics," in which a system uses microchannels to transport and manipulate trace gases at the microscopic scale to build a highly versatile integrated system based on gas-gas or gas-liquid microinteractions is proposed. A kind of underwater aerofluidic architecture is designed using superhydrophobic surface microgrooves written by a femtosecond laser. In the aqueous medium, a hollow microchannel is formed between the superhydrophobic microgrooves and the water environment, which allows gas to flow freely underwater for aerofluidic devices. Driven by Laplace pressure, gas can be self-transported along various complex patterned paths, curved surfaces, and even across different aerofluidic devices, with an ultralong transportation distance of more than 1 m. The width of the superhydrophobic microchannels of the designed aerofluidic devices is only ≈42.1 µm, enabling the aerofluidic system to achieve accurate gas transportation and control. With the advantages of flexible self-driving gas transportation and ultralong transportation distance, the underwater aerofluidic devices can realize a series of gas control functions, such as gas merging, gas aggregation, gas splitting, gas arrays, gas-gas microreactions, and gas-liquid microreactions. It is believed that underwater aerofluidic technology can have significant applications in gas-involved microanalysis, microdetection, biomedical engineering, sensors, and environmental protection.

Manganese(II)-Guided Separation in the Sub-Nanometer Regime for Precise Identification of In Vivo Size Dependence

A precise understanding of nano-bio interactions in the sub-nanometer regime is necessary for advancements in nanomedicine. However, this is currently hindered by the control of the nanoparticle size in the sub-nanometer regime. Herein, we report a facile in situ Mn²⁺ -guided centrifugation strategy for the synthesis of large-scale ultrasmall gold nanoparticles (AuNPs) with a precisely controlled size gradient at the sub-nanometer regime. With the discovery that [Mn(OH)]⁺ , especially metallic manganese (Mn⁰ @[Mn(OH)]⁺ ) nanoparticles, could selectively interact with larger AuNPs through synergistic coordination and hydrogen bonding to form aggregates, we also realized the fast (<1 h) synthesis of water-soluble atomically precise Au₂₅ with high yields (>56 %). We further demonstrated that sub-nanometer size differences (approximately 0.5 nm) significantly alter non-specific phagocytosis of AuNPs in the reticuloendothelial system macrophages, elimination rate, and nanotoxicology.

Overcoming drug resistance with a docetaxel and disulfiram loaded pH-sensitive nanoparticle

Previous studies have demonstrated that breast cancer cells deploy a myriad array of strategies to thwart the activity of anticancer drugs like docetaxel (DTX), including acquired drug resistance due to overexpression of drug-efflux pumps like P-glycoprotein (P-gp) and innate drug resistance by cancer stem cells (CSCs). As disulfiram (DSF) can inhibit both P-gp and CSCs, we hypothesized that co-treatment of DTX and DSF could sensitize the drug-resistant breast cancer cells. To deliver a fixed dose ratio of DTX and DSF targeted to the tumor, a tumor extracellular pH-responsive nanoparticle (NP) was developed using a histidine-conjugated star-shaped PLGA with TPGS surface decoration ([DD]NpH-T). By releasing the encapsulated drugs in the tumor microenvironment, pH-sensitive NPs can overcome the tumor stroma-based resistance against nanomedicines. In in-vitro studies, [DD]NpH-T exhibited increased drug release at pH 6.8, improved penetration in a 3D tumor spheroid, reduced serum protein adsorption, and enhanced cytotoxic efficacy against both innate and acquired DTX-resistant breast cancer cells. In in-vivo studies, a significant increase in plasma AUC and tumor drug delivery was observed with [DD]NpH-T, which resulted in an enhanced in-vivo anti-tumor efficacy against a mouse orthotopic breast cancer, with a significantly increased intratumoral ROS and apoptosis, while decreasing P-gp expression and prevention of lung metastasis. Altogether, the current study demonstrated that the DTX and DSF combination could effectively target multiple drug-resistance pathways in-vitro, and the in-vivo delivery of this drug combination using TPGS-decorated pH-sensitive NPs could increase tumor accumulation, resulting in improved anti-tumor efficacy.

Microfluidics-enabled Serial Assembly of Lipid-siRNA-sorafenib Nanoparticles for Synergetic Hepatocellular Carcinoma Therapy

Multi-component nanoparticles (mNPs) hold great potential for disease prevention and treatment. However, a major barrier is the lack of versatile platforms to accommodate steps of assembly processes of mNPs. Here the microfluidics-enabled serial assembly (MESA) of mNPs is presented. The microfluidic chip, as a mini-conveyor of initial materials, sequentially enables the assembly of sorafenib supramolecule, electrostatic adsorption of siRNA, and surface assembly of protective lipids. The produced lipid-siRNA-sorafenib nanoparticles (LSS NPs) have ultrahigh encapsulation efficiencies for sorafenib (≈100%) and siRNA (≈95%), which benefit from the accommodation of both fast and slow processes on the chip. Although carrying negative charges, LSS NPs enable cytosolic delivery of agents and high gene silencing efficiency within tumor cells. In vivo, the LSS NPs delivering hypoxia-induced factor (HIF1α)-targeted siRNA efficiently regress tumors of Hep3B xenograft and hepatocellular carcinoma patient-derived primary cells xenograft (PDCX) and finally extend the average survival of PDCX mice to 68 days. Thus, this strategy is promising as a sorafenib/siRNA combination therapy, and MESA can be a universal platform for fabricating complex nanosystems.

Microfluidic preparation and optimization of sorafenib-loaded poly(ethylene glycol-block-caprolactone) nanoparticles for cancer therapy applications

The use of amphiphilic block copolymers to generate colloidal delivery systems for hydrophobic drugs has been the subject of extensive research, with several formulations reaching the clinical development stages. However, to generate particles of uniform size and morphology, with high encapsulation efficiency, yield and batch-to-batch reproducibility remains a challenge, and various microfluidic technologies have been explored to tackle these issues. Herein, we report the development and optimization of poly(ethylene glycol)-block-(ε-caprolactone) (PEG-b-PCL) nanoparticles for intravenous delivery of a model drug, sorafenib. We developed and optimized a glass capillary microfluidic nanoprecipitation process and studied systematically the effects of formulation and process parameters, including different purification techniques, on product quality and batch-to-batch variation. The optimized formulation delivered particles with a spherical morphology, small particle size (d_H < 80 nm), uniform size distribution (PDI < 0.2), and high drug loading degree (16 %) at 54 % encapsulation efficiency. Furthermore, the stability and in vitro drug release were evaluated, showing that sorafenib was released from the NPs in a sustained manner over several days. Overall, the study demonstrates a microfluidic approach to produce sorafenib-loaded PEG-b-PCL NPs and provides important insight into the effects of nanoprecipitation parameters and downstream processing on product quality.

A clinically translatable kit for MRI/NMI dual-modality nanoprobes based on anchoring group-mediated radiolabeling

Magnetic resonance imaging (MRI)/nuclear medicine imaging (NMI) dual-modality imaging based on radiolabeled nanoparticles has been increasingly exploited for accurate diagnosis of tumor and cardiovascular diseases by virtue of high spatial resolution and high sensitivity. However, significant challenges exist in pursuing truly clinical applications, including massive preparation and rapid radiolabeling of nanoparticles. Herein, we report a clinically translatable kit for the convenient construction of MRI/NMI nanoprobes relying on the flow-synthesis and anchoring group-mediated radiolabeling (LAGMERAL) of iron oxide nanoparticles. First, homogeneous iron oxide nanoparticles with excellent performance were successfully obtained on a large scale by flow synthesis, followed by the surface anchoring of diphosphonate-polyethylene glycol (DP-PEG) to simultaneously render the underlying nanoparticles biocompatible and competent in robust labeling of radioactive metal ions. Moreover, to enable convenient and safe usage in clinics, the DP-PEG modified nanoparticle solution was freeze-dried and sterilized to make a radiolabeling kit followed by careful evaluations of its in vitro and in vivo performance and applicability. The results showed that ^99mTc labeled nanoprobes are effectively obtained with a labeling yield of over 95% in 30 minutes after simply injecting Na[^99mTcO₄] solution into the kit. In addition, the Fe₃O₄ nanoparticles sealed in the kit can well stand long-term storage even for 300 days without deteriorating the colloidal stability and radiolabeling yield. Upon intravenous injection of the as-prepared radiolabeled nanoprobes, high-resolution vascular images of mice were obtained by vascular SPECT imaging and magnetic resonance angiography, demonstrating the promising clinical translational value of our radiolabeling kit.

High-Precision Synthesis of RNA-Loaded Lipid Nanoparticles for Biomedical Applications

The recent development of RNA-based therapeutics in delivering nucleic acids for gene editing and regulating protein translation has led to the effective treatment of various diseases including cancer, inflammatory and genetic disorder, as well as infectious diseases. Among these, lipid nanoparticles (LNP) have emerged as a promising platform for RNA delivery and have shed light by resolving the inherent instability issues of naked RNA and thereby enhancing the therapeutic potency. These LNP consisting of ionizable lipid, helper lipid, cholesterol, and poly(ethylene glycol)-anchored lipid can stably enclose RNA and help them release into the cells' cytosol. Herein, the significant progress made in LNP research starting from the LNP constituents, formulation, and their diverse applications is summarized first. Moreover, the microfluidic methodologies which allow precise assembly of these newly developed constituents to achieve LNP with controllable composition and size, high encapsulation efficiency as well as scalable production are highlighted. Furthermore, a short discussion on current challenges as well as an outlook will be given on emerging approaches to resolving these issues.

Increasing stiffness promotes pulmonary retention of ligand-directed dexamethasone-loaded nanoparticle for enhanced acute lung inflammation therapy

Inhaled nanoparticles (NPs) need to penetrate the bronchial mucosa to deliver drug payloads deeply in the lung for amplified local therapy. However, the bronchial mucociliary barrier eliminates NPs rapidly, which considerably limits their mucosal penetration. In this study, we find that surface ligand modification and stiffness adjustment of NPs contribute to the significantly enhanced bronchial mucosal absorption and pulmonary retention of inhaled drugs. We utilize neonatal Fc receptor ligand (FcBP) to modify the rationally designed low stiffness NPs (Soft-NP) and high stiffness NPs (Stiff-NP) to target bronchial mucosa. In an acute lung inflammation rat model, after intranasal administration with dexamethasone-loaded NPs, Stiff-NP endowed with FcBP displays superior therapeutic effects. The in vitro data demonstrate that the promotion effect of FcBP to bronchial mucosal absorption of Stiff-NP dominates over Soft-NP. This could be attributed to the higher affinity between ligand-receptor when incorporating FcBP on the Stiff-NP surface. Meanwhile, high stiffness modulates more actin filaments aggregation to mediate endocytosis, along with strengthened Ca2+ signal to enhance exocytosis. Conclusively, we highlight that FcBP-modified NPs with higher stiffness would be a potential pulmonary drug delivery system.

Crosslinked zwitterionic microcapsules to overcome gastrointestinal barriers for oral insulin delivery

Oral insulin delivery has been extensively considered to achieve great patient compliance and convenience as well as favourable glucose homeostasis. However, its application is highly limited by the low insulin bioavailability owing to gastrointestinal barriers. Herein, we developed crosslinked zwitterionic microcapsules (CB-MCs@INS) based on a carboxyl betaine (CB)-modified poly(acryloyl carbonate-co-caprolactone) copolymer via the combination of microfluidics and UV-crosslinking to improve oral insulin delivery. CB-MC@INS microcapsules with high drug loading capacity (>40%) protected insulin from acid degradation in the harsh gastric environment. Through the introduction of CB-moieties, CB-MCs@INS possessed superior affinity for epithelial cells and improved insulin transport as compared to non-CB modified MCs@INS (5.15-fold), which was mainly attributed to the CB-mediated cell surface transporter via the PAT1 pathway. Moreover, the oral administration of CB-MCs@INS exhibited an excellent hypoglycaemic effect and maintained normoglycemia for up to 8 h in diabetic mice, demonstrating the great potential of crosslinked zwitterionic microcapsules as an oral insulin delivery platform for diabetes therapy.

Microfluidic nanodevices for drug sensing and screening applications

The outbreak of pandemics (e.g., severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 in 2019), influenza A viruses (H1N1 in 2009), etc.), and worldwide spike in the aging population have created unprecedented urgency for developing new drugs to improve disease treatment. As a result, extensive efforts have been made to design novel techniques for efficient drug monitoring and screening, which form the backbone of drug development. Compared to traditional techniques, microfluidics-based platforms have emerged as promising alternatives for high-throughput drug screening due to their inherent miniaturization characteristics, low sample consumption, integration, and compatibility with diverse analytical strategies. Moreover, the microfluidic-based models utilizing human cells to produce in-vitro biomimetics of the human body pave new ways to predict more accurate drug effects in humans. This review provides a comprehensive summary of different microfluidics-based drug sensing and screening strategies and briefly discusses their advantages. Most importantly, an in-depth outlook of the commonly used detection techniques integrated with microfluidic chips for highly sensitive drug screening is provided. Then, the influence of critical parameters such as sensing materials and microfluidic platform geometries on screening performance is summarized. This review also outlines the recent applications of microfluidic approaches for screening therapeutic and illicit drugs. Moreover, the current challenges and the future perspective of this research field is elaborately highlighted, which we believe will contribute immensely towards significant achievements in all aspects of drug development.

Poly (beta-amino ester) as an in vivo nanocarrier for therapeutic nucleic acids

Therapeutic nucleic acids are an emerging class of therapy for treating various diseases through immunomodulation, protein replacement, gene editing, and genetic engineering. However, they need a vector to effectively and safely reach the target cells. Most gene and cell therapies rely on ex vivo gene delivery, which is laborious, time-consuming, and costly; therefore, devising a systematic vector for effective and safe in vivo delivery of therapeutic nucleic acids is required to target the cells of interest in an efficient manner. Synthetic nanoparticle vector poly beta amino ester (PBAE), a class of degradable polymer, is a promising candidate for in vivo gene delivery. PBAE is considered the most potent in vivo vector due to its excellent transfection performance and biodegradability. PBAE nanoparticles showed tunable charge density, diverse structural characteristics, excellent encapsulation capacity, high stability, stimuli-responsive release, site-specific delivery, potent binding to nucleic acids, flexible binding ability to various conjugates, and effective endosomal escape. These unique properties of PBAE are an essential contribution to in vivo gene delivery. The current review discusses each of the components used for PBAE synthesis and the impact of various environmental and physicochemical factors of the body on PBAE nanocarrier.

Exploring mitigating role of zinc nanoparticles on arsenic, ammonia and temperature stress using molecular signature in fish

BACKGROUND

The pollution and climate change in aquatic ecosystems are major problems threatening the aquatic organisms for existence in the recent timeline, which promotes the extinction of the fish species. However, the present study dealt with zinc nanoparticles (Zn-NPs) in mitigating arsenic, ammonia and high temperature stresses in Pangasianodon hypophthalmus.

MATERIALS AND METHODS

To studying different gene expressions, an experiment was conducted to mitigate the multiple stressors using dietary Zn-NPs at 0, 2, 4, and 6 mg kg^-1 diets. In the present investigation, the gene expressions studies were performed for growth hormone regulator 1 (GHR1), growth hormone regulator β (GHRβ), growth hormone (GR) in liver and gill tissue as well as myostatin (MYST) and somatostatin (SMT) in the muscle tissue. The anti-oxidative genes CAT, SOD and GPx in liver and gill tissues were also analysed. Expression studies for stress responsive heat shock protein gene (HSP70), DNA damage inducible protein, inducible nitric oxide synthase (iNOS), immune related genes such as interleukin (IL), tumour necrosis factor (TNFα), toll like receptor (TLR) and immunoglobulin were performed. At the end of the experiment the fish were infected with Aeromonas hydrophila to evaluate the immunomodulatory role of Zn-NPs.

RESULTS

In the present investigation, the growth hormone regulator 1 (GHR1), growth hormone regulator β (GHRβ), growth hormone (GR) in liver and gill as well as myostatin (MYST) and somatostatin (SMT) in muscle were noticeably altered, whereas, Zn-NPs at 4 mg kg^-1 diet improved gene expressions. The anti-oxidant gene viz. CAT, SOD and GPx in liver and gill tissues were upregulated by stressors such as As, NH₃, NH₃+T. As+T and As+NH₃+T. Therefore, anti-oxidant genes were noticeably improved with dietary Zn-NPs diet. The stress protein gene (HSP70), DNA damage inducible protein, inducible nitric oxide synthase (iNOS) was significantly upregulated, whereas, Zn-NPs diet was applied to the corrected gene regulation. Similarly, immune related genes such as interleukin (IL), tumour necrosis factor (TNFα), toll like receptor (TLR) and immunoglobulin were highly affected by stressors. Dietary Zn-NPs at 4 mg kg^-1 diet was improved all the immune related gene expression and mitigate arsenic, ammonia and high temperature stress in fish.

CONCLUSION

The present investigation revealed that Zn-NPs at 4.0 mg kg^-1 diet has enormous potential to modulates arsenic, ammonia and high temperature stress, and protect against pathogenic infections in fish.

Evaluation and manipulation of tissue and cellular distribution of cardiac progenitor cell-derived extracellular vesicles

Cardiac progenitor cell-derived extracellular vesicles (CPC-EVs) have been successfully applied via different delivery routes for treating post-myocardial infarction injury in several preclinical models. Hence, understanding the in vivo fate of CPC-EVs after systemic or local, i.e. myocardial, delivery is of utmost importance for the further therapeutic application of CPC-EVs in cardiac repair. Here, we studied the tissue- and cell distribution and retention of CPC-EVs after intramyocardial and intravenous injection in mice by employing different EV labeling and imaging techniques. In contrast to progenitor cells, CPC-EVs demonstrated no immediate flush-out from the heart upon intramyocardial injection and displayed limited distribution to other organs over time, as determined by near-infrared imaging in living animals. By employing CUBIC tissue clearing and light-sheet fluorescent microscopy, we observed CPC-EV migration in the interstitial space of the myocardium shortly after EV injection. Moreover, we demonstrated co-localization with cTnI and CD31-positive cells, suggesting their interaction with various cell types present in the heart. On the contrary, after intravenous injection, most EVs accumulated in the liver. To potentiate such a potential systemic cardiac delivery route, targeting the cardiac endothelium could provide openings for directed CPC-EV therapy. We therefore evaluated whether decorating EVs with targeting peptides (TPs) RGD-4C or CRPPR connected to Lamp2b could enhance EV delivery to endothelial cells. Expression of both TPs enhanced CPC-EV uptake under in vitro continuous flow, but did not affect uptake under static cell culture conditions. Together, these data demonstrate that the route of administration influences CPC-EV biodistribution pattern and suggest that specific TPs could be used to target CPC-EVs to the cardiac endothelium. These insights might lead to a better application of CPC-EV therapeutics in the heart.

Development and Evaluation of PLGA Nanoparticle-Loaded Organogel for the Transdermal Delivery of Risperidone

A transdermal delivery approach may circumvent the limitations associated with the oral use of risperidone (RIS), an atypical antipsychotic drug. The current study focuses on the utilization of poloxamer (pluronic) lecithin organogel (PLO), a suitable transdermal vehicle, and a biodegradable nanoparticulate system of PLGA with the potential to deliver RIS in an efficient way. PLGA nanoparticles were fabricated using different ratios of the polymer and surfactant. The optimization was performed principally on the basis of particle size and entrapment efficiency (EE). The developed PLGA nanoparticles were spherical, sized around 109 nm with negative charge (−9.3 mv) and enhanced drug entrapment efficiency (58%). The in vitro drug release study of lyophilized nanoparticles showed a sustained pattern. Statistical analysis confirmed that there was a significant difference (p < 0.05) between the nanoparticle-loaded PLO gel and conventional drug formulations in terms of drug release and ex vivo permeation across rat skin (three-fold). The results confirm enhanced drug release and permeation through the skin at 72 h. Hence, the investigated formulation could be a better alternative to the conventional route for improving patient compliance.

Sustained Drug Release from Smart Nanoparticles in Cancer Therapy: A Comprehensive Review

Although nanomedicine has been highly investigated for cancer treatment over the past decades, only a few nanomedicines are currently approved and in the market; making this field poorly represented in clinical applications. Key research gaps that require optimization to successfully translate the use of nanomedicines have been identified, but not addressed; among these, the lack of control of the release pattern of therapeutics is the most important. To solve these issues with currently used nanomedicines (e.g., burst release, systemic release), different strategies for the design and manufacturing of nanomedicines allowing for better control over the therapeutic release, are currently being investigated. The inclusion of stimuli-responsive properties and prolonged drug release have been identified as effective approaches to include in nanomedicine, and are discussed in this paper. Recently, smart sustained release nanoparticles have been successfully designed to safely and efficiently deliver therapeutics with different kinetic profiles, making them promising for many drug delivery applications and in specific for cancer treatment. In this review, the state-of-the-art of smart sustained release nanoparticles is discussed, focusing on the design strategies and performances of polymeric nanotechnologies. A complete list of nanomedicines currently tested in clinical trials and approved nanomedicines for cancer treatment is presented, critically discussing advantages and limitations with respect to the newly developed nanotechnologies and manufacturing methods. By the presented discussion and the highlight of nanomedicine design criteria and current limitations, this review paper could be of high interest to identify key features for the design of release-controlled nanomedicine for cancer treatment.

Microfluidic formulation of lipid/polymer hybrid nanoparticles for plasmid DNA (pDNA) delivery

Lipid/polymer hybrid nanoparticles loaded with red fluorescent protein (RFP) encoded plasmid DNA (pDNA) was formulated using poly-lactic-co-glycolic acid (PLGA), cationic lipid DC-cholesterol and surfactant mPEG₂₀₀₀- DSPE. A lipid/ polymer ratio of 1: 10 at 1 mg/mL surfactant concentration was found to be optimal for producing nanoparticles with diameters of 100-120 nm that remained stable upon ultracentrifugation. The production of lipid/ polymer hybrid nanoparticles was investigated using microfluidics with a toroidal mixer design. Our results showed that the flow parameters significantly influenced the physicochemical characteristics of nanoparticles and loading of pDNA was only achieved at flow rate ratio (FRR) of 3: 1. The pDNA associated with nanoparticles was demonstrated to be structurally intact using gel electrophoresis, and the encapsulation efficiency (EE) was measured to be ∼65%. The prepared hybrid nanoparticles resulted in 20% of transfection efficacy in human embryonic kidney cells (HEK293T). This study demonstrated the potential of microfluidics in the development of hybrid nanoparticles for pDNA delivery, thus facilitating the clinical translation of DNA therapeutics.

Navigating ethical challenges in the development and translation of biomaterials research

Biomaterials--from implanted iron teeth in the second century to intraocular lenses, artificial joints, and stents today--have long been used clinically. Today, biomaterials researchers and biomedical engineers are pushing beyond these inert synthetic alternatives and incorporating complex multifunctional materials to control biological interactions and direct physiological processes. These advances are leading to novel strategies for targeted drug delivery, drug screening, diagnostics and imaging, gene therapy, tissue regeneration, and cell transplantation. While the field has survived ethical transgressions in the past, the rapidly expanding scope of biomaterials science, combined with the accelerating clinical translation of this diverse field calls for urgent attention to the complex and challenging ethical dilemmas these advances pose. This perspective responds to this call, examining the intersection of research ethics -- the sets of rules, principles and norms guiding responsible scientific inquiry -- and ongoing advances in biomaterials. While acknowledging the inherent tensions between certain ethical norms and the pressures of the modern scientific and engineering enterprise, we argue that the biomaterials community needs to proactively address ethical issues in the field by, for example, updating or adding specificity to codes of ethics, modifying training programs to highlight the importance of ethical research practices, and partnering with funding agencies and journals to adopt policies prioritizing the ethical conduct of biomaterials research. Together these actions can strengthen and support biomaterials as its advances are increasingly commercialized and impacting the health care system.

A Review of Microfluidic Experimental Designs for Nanoparticle Synthesis

Microfluidics is defined as emerging science and technology based on precisely manipulating fluids through miniaturized devices with micro-scale channels and chambers. Such microfluidic systems can be used for numerous applications, including reactions, separations, or detection of various compounds. Therefore, due to their potential as microreactors, a particular research focus was noted in exploring various microchannel configurations for on-chip chemical syntheses of materials with tailored properties. Given the significant number of studies in the field, this paper aims to review the recently developed microfluidic devices based on their geometry particularities, starting from a brief presentation of nanoparticle synthesis and mixing within microchannels, further moving to a more detailed discussion of different chip configurations with potential use in nanomaterial fabrication.

Where Is Nano Today and Where Is It Headed? A Review of Nanomedicine and the Dilemma of Nanotoxicology

Worldwide nanotechnology development and application have fueled many scientific advances, but technophilic expectations and technophobic demands must be counterbalanced in parallel. Some of the burning issues today are the following: (1) Where is nano today? (2) How good are the communication and investment networks between academia/research and governments? (3) Is there any spotlight application for nanotechnology? Nanomedicine is a particular arm of nanotechnology within the healthcare landscape, focused on diagnosis, treatment, and monitoring of emerging (such as coronavirus disease 2019, COVID-19) and contemporary (including diabetes, cardiovascular diseases, neurodegenerative disorders, and cancer) diseases. However, it may only represent the bright side of the coin. In fact, in the recent past, the concept of nanotoxicology has emerged to address the dark shadows of nanomedicine. The nanomedicine field requires more nanotoxicological studies to identify undesirable effects and guarantee safety. Here, we provide an overall perspective on nanomedicine and nanotoxicology as central pieces of the giant puzzle of nanotechnology. First, the impact of nanotechnology on education and research is highlighted, followed by market trends and scientific output tendencies. In the next section, the nanomedicine and nanotoxicology dilemma is addressed through the interplay of in silico, in vitro, and in vivo models with the support of omics and microfluidic approaches. Lastly, a reflection on the regulatory issues and clinical trials is provided. Finally, some conclusions and future perspectives are proposed for a clearer and safer translation of nanomedicines from the bench to the bedside.

Microfluidic Paper-Based Analytical Devices for the Determination of Food Contaminants: Developments and Applications

Food safety is an issue that cannot be ignored at any time because of the great impact of food contaminants on people's daily life, social production, and the economy. Because of the extensive demand for high-quality food, it is necessary to develop rapid, reliable, and efficient devices for food contaminant detection. Microfluidic paper-based analytical devices (μPADs) have been applied in a variety of detection fields owing to the advantages of low-cost, ease of handling, and portability. This review systematically discusses the latest progress of μPADs, including the fundamentals of fabrication as well as applications in the detection of chemical and biological hazards in foods, hoping to provide suitable screening strategies for contaminants in foods and accelerating the technology transformation of μPADs from the lab into the field.