Recent Advances of Microfluidic Platforms for Controlled Drug Delivery in Nanomedicine

Novel microfluidic development of pH-responsive hybrid liposomes: In vitro and in vivo assessment for enhanced wound Healing

Wound healing is a complex biological process crucial for tissue repair, especially in chronic wounds where healing is impaired. Liposomes have emerged as promising vehicles for delivering therapeutics to facilitate wound repair. Liposomes have been explored as effective carriers for therapeutic agents. However, traditional methods of liposome preparation face significant challenges, particularly in achieving consistent stability and precise control over drug encapsulation and release. This study addresses these challenges by pioneering the development of Hybrid Liposomes (HLPs) using microfluidic technology, which provides more controlled characteristics through precisely managed formulation parameters. Notably, the formation of Polydopamine (PDA) polymer within HLPs facilitates pH-responsive drug release, making them well-suited for acidic wound environments. Furthermore, surface modification with Folic Acid (FA) enhances cellular interaction with the HLPs. In vitro and in vivo studies demonstrate the efficacy of HLPs loaded with Hyaluronic Acid (HA) or Phenytoin (PHT) in promoting wound healing. Microfluidics optimizes the stability of HLPs over 90 days, underscoring their potential as a potent, antibiotic-free drug delivery system. In conclusion, this research advances the understanding of microfluidic optimization for HLPs, offering cutting-edge drug delivery systems. The transformative potential of targeted HLPs through microfluidics holds promise for revolutionizing wound healing and inspires optimism for effective therapeutic interventions.

Strategies for Improved pDNA Loading and Protection Using Cationic and Neutral LNPs with Industrial Scalability Potential Using Microfluidic Technology

Purpose

In recent years, microfluidic technologies have become mainstream in producing gene therapy nanomedicines (NMeds) following the Covid-19 vaccine; however, extensive optimizations are needed for each NMed type and genetic material. This article strives to improve LNPs for pDNA loading, protection, and delivery, while minimizing toxicity.

Methods

The microfluidic technique was optimized to form cationic or neutral LNPs to load pDNA. Classical "post-formulation" DNA addition vs "pre" addition in the aqueous phase were compared. All formulations were characterized (size, homogeneity, zeta potential, morphology, weight yield, and stability), then tested for loading efficiency, nuclease protection, toxicity, and cell uptake.

Results

Optimized LNPs formulated with DPPC: Chol:DOTAP 1:1:0.1 molar ratio and 10 µg of DOPE-Rhod, had a size of 160 nm and good homogeneity. The chemico-physical characteristics of cationic LNPs worsened when adding 15 µg/mL of pDNA with the "post" method, while maintaining their characteristics up to 100 µg/mL of pDNA with the "pre" addition remaining stable for 30 days. Interestingly, neutral LNPs formulated with the same method loaded up to 50% of the DNA. Both particles could protect the DNA from nucleases even after one month of storage, and low cell toxicity was found up to 40 µg/mL LNPs. Cell uptake occurred within 2 hours for both formulations with the DNA intact in the cytoplasm, outside of the lysosomes.

Conclusion

In this study, the upcoming microfluidic technique was applied to two strategies to generate pDNA-LNPs. Cationic LNPs could load 10x the amount of DNA as the classical approach, while neutral LNPs, which also loaded and protected DNA, showed lower toxicity and good DNA protection. This is a big step forward at minimizing doses and toxicity of LNP-based gene therapy.

Microfluidics for personalized drug delivery

This review highlights the transformative impact of microfluidic technology on personalized drug delivery. Microfluidics addresses issues in traditional drug synthesis, providing precise control and scalability in nanoparticle fabrication, and microfluidic platforms show high potential for versatility, offering patient-specific dosing and real-time monitoring capabilities, all integrated into wearable technology. Covalent conjugation of antibodies to nanoparticles improves bioactivity, driving innovations in drug targeting. The integration of microfluidics with sensor technologies and artificial intelligence facilitates real-time feedback and autonomous adaptation in drug delivery systems. Key challenges, such as droplet polydispersity and fluidic handling, along with future directions focusing on scalability and reliability, are essential considerations in advancing microfluidics for personalized drug delivery.

Closed, one-stop intelligent and accurate particle characterization based on micro-Raman spectroscopy and digital microfluidics

Monoclonal antibodies are prone to form protein particles through aggregation, fragmentation, and oxidation under varying stress conditions during the manufacturing, shipping, and storage of parenteral drug products. According to pharmacopeia requirements, sub-visible particle levels need to be controlled throughout the shelf life of the product. Therefore, in addition to determining particle counts, it is crucial to accurately characterize particles in drug product to understand the stress condition of exposure and to implement appropriate mitigation actions for a specific formulation. In this study, we developed a new method for intelligent characterization of protein particles using micro-Raman spectroscopy on a digital microfluidic chip (DMF). Several microliters of protein particle solutions induced by stress degradation were loaded onto a DMF chip to generate multiple droplets for Raman spectroscopy testing. By training multiple machine learning classification models on the obtained Raman spectra of protein particles, eight types of protein particles were successfully characterized and predicted with high classification accuracy (93%-100%). The advantages of the novel particle characterization method proposed in this study include a closed system to prevent particle contamination, one-stop testing of morphological and chemical structure information, low sample volume consumption, reusable particle droplets, and simplified data analysis with high classification accuracy. It provides great potential to determine the probable root cause of the particle source or stress conditions by a single testing, so that an accurate particle control strategy can be developed and ultimately extend the product shelf-life.

Preparation of Tetrandrine Nanocrystals by Microfluidic Method and Its In Vitro and In Vivo Evaluation

The anti-hepatocellular carcinoma effects of TET are acknowledged, but its application is hindered by its poor water solubility and low bioavailability. Conventional methods for nanocrystal preparation are laborious and lack control. To address these limitations, we propose employing the microfluidic method in the preparation of TET nanocrystals, aiming to enhance the aforementioned constraints. The objectives of this study were to prepare TET nanocrystals (TET-NC@GL) using a Y-microfluidic method with glycyrrhetinic acid (GL) as a stabilizer. The optimal preparation prescription was determined through a single-factor test and Box-Behnken response surface method. Additionally, the nanocrystals prepared with the commonly used stabilizer polyvinylpyrrolidone K30 (PVPK30), known as TET-NC@PVPK30, were characterized and evaluated for their toxicity to HepG2 cells. Hybridized nanocrystals (TET-HNC@GL and TET-HNC@PVPK30) were synthesized using a water-soluble aggregation-induced emission (AIE) fluorescent probe (TVP). Qualitative and quantitative cellular uptake experiments were conducted using these hybridized nanocrystals. Conducting in vivo pharmacokinetic assays evaluates the relative bioavailability of nanocrystals. The results indicated that TET-NC@GL, optimized using the response surface method, had a particle size of 136.47 ± 3.31 nm and a PDI of 0.219 ± 0.002. The administration of TET-NC@GL significantly enhanced the cell inhibition rate compared to the TET group and the TET-NC@PVPK30 group (P < 0.01). Moreover, the qualitative and quantitative cellular uptake results revealed a significant enhancement in cellular uptake in the TET-HNC@GL administration group compared to the TET-HNC@PVPK30 group (P < 0.01). In vivo pharmacokinetic results showed that the bioavailability of TET-NC@GL group was 3.5 times higher than that of the TET group. The results demonstrate the successful preparation of TET-NC@GL nanocrystals.

Organoids technology for advancing the clinical translation of cancer nanomedicine

The past decades have witnessed the rapid development and widespread application of nanomedicines in cancer treatment; however, the clinical translation of experimental findings has been low, as evidenced by the low percentage of commercialized nanomedicines. Incomplete understanding of nanomedicine-tumor interactions and inappropriate evaluation models are two important challenges limiting the clinical translation of cancer nanomedicines. Currently, nanomedicine-tumor interaction and therapeutic effects are mainly investigated using cell lines or mouse models, which do not recapitulate the complex tumor microenvironment in human patients. Thus, information obtained from cell lines and mouse models cannot provide adequate guidance for the rational redesign of nanomedicine. Compared with other preclinical models, tumor organoids constructed from patient-derived tumor tissues are superior in retaining the key histopathological, genetic, and phenotypic features of the parent tumor. We speculate that organoid technology would help elucidate nanomedicine-tumor interaction in the tumor microenvironment and guide the design of nanomedicine, making it a reliable tool to accurately predict drug responses in patients with cancer. This review highlighted the advantages of drug delivery systems in cancer treatment, challenges limiting the clinical translation of antitumor nanomedicines, and potential application of patient-derived organoids (PDO) in nanomedicine. We propose that combining organoids and nanotechnology would facilitate the development of safe and effective cancer nanomedicines and accelerate their clinical application. This review discussed the potential translational value of integrative research using organoids and cancer nanomedicine. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Microfluidics: Insights into Intestinal Microorganisms

Microfluidics is a system involving the treatment or manipulation of microscale (10^-9 to 10^-18 L) fluids using microchannels (10 to 100 μm) contained on a microfluidic chip. Among the different methodologies used to study intestinal microorganisms, new methods based on microfluidic technology have been receiving increasing attention in recent years. The intestinal tracts of animals are populated by a vast array of microorganisms that have been established to play diverse functional roles beneficial to host physiology. This review is the first comprehensive coverage of the application of microfluidics technology in intestinal microbial research. In this review, we present a brief history of microfluidics technology and describe its applications in gut microbiome research, with a specific emphasis on the microfluidic technology-based intestine-on-a-chip, and also discuss the advantages and application prospects of microfluidic drug delivery systems in intestinal microbial research.

Nanobiotechnological approaches in osteosarcoma therapy: Versatile (nano)platforms for theranostic applications

Constructive achievements in the field of nanobiotechnology and their translation into clinical course have led to increasing attention towards evaluation of their use for treatment of diseases, especially cancer. Osteosarcoma (OS) is one of the primary bone malignancies that affects both males and females in childhood and adolescence. Like other types of cancers, genetic and epigenetic mutations account for OS progression and several conventional therapies including chemotherapy and surgery are employed. However, survival rate of OS patients remains low and new therapies in this field are limited. The purpose of the current review is to provide a summary of nanostructures used in OS treatment. Drug and gene delivery by nanoplatforms have resulted in an accumulation of therapeutic agents for tumor cell suppression. Furthermore, co-delivery of genes and drugs by nanostructures are utilized in OS suppression to boost immunotherapy. Since tumor cells have distinct features such as acidic pH, stimuli-responsive nanoparticles have been developed to appropriately target OS. Besides, nanoplatforms can be used for biosensing and providing phototherapy to suppress OS. Furthermore, surface modification of nanoparticles with ligands can increase their specificity and selectivity towards OS cells. Clinical translation of current findings suggests that nanoplatforms have been effective in retarding tumor growth and improving survival of OS patients.

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.