Application of Magnesium Pyrophosphate-Based Sponge-Like Microparticles to Enhance the Delivery Efficiency and Adjuvant Effects of Polyriboinosinic-Polyribocytidylic Acid in Immune Cells

Exploiting machine learning for bestowing intelligence to microfluidics

Intelligent microfluidics is an emerging cross-discipline research area formed by combining microfluidics with machine learning. It uses the advantages of microfluidics, such as high throughput and controllability, and the powerful data processing capabilities of machine learning, resulting in improved systems in biotechnology and chemistry. Compared to traditional microfluidics using manual analysis methods, intelligent microfluidics needs less human intervention, and results in a more user-friendly experience with faster processing. There is a paucity of literature reviewing this burgeoning and highly promising cross-discipline. Therefore, we herein comprehensively and systematically summarize several aspects of microfluidic applications enabled by machine learning. We list the types of microfluidics used in intelligent microfluidic applications over the last five years, as well as the machine learning algorithms and the hardware used for training. We also present the most recent advances in key technologies, developments, challenges, and the emerging opportunities created by intelligent microfluidics.

Cytosolic delivery of the immunological adjuvant Poly I:C and cytotoxic drug crystals via a carrier-free strategy significantly amplifies immune response

Co-delivery of chemotherapeutics and immunostimulant or chemoimmunotherapy is an emerging strategy in cancer therapy. The precise control of the targeting and release of agents is critical in this methodology. This article proposes the asynchronous release of the chemotherapeutic agents and immunostimulants to realize the synergistic effect between chemotherapy and immunotherapy. To obtain a proof-of-concept, a co-delivery system was prepared via a drug-delivering-drug (DDD) strategy for cytosolic co-delivery of Poly I:C, a synthetic dsRNA analog to activate RIG-I signaling, and PTX, a commonly used chemotherapeutics, in which pure PTX nanorods were sequentially coated with Poly I:C and mannuronic acid via stimulating the RIG-I signaling axis. The co-delivery system with a diameter of 200 nm enables profound immunogenicity of cancer cells, exhibiting increased secretion of cytokines and chemokines, pronounced immune response in vivo, and significant inhibition of tumor growth. Also, we found that intracellularly sustained release of cytotoxic agents could elicit the immunogenicity of cancer cells. Overall, the intracellular asynchronous release of chemotherapeutics and immunomodulators is a promising strategy to promote the immunogenicity of cancer cells and augment the antitumor immune response.

Viscosity-Regulated Control of RNA Microstructure Fabrication

The development of RNA self-assemblies offers a powerful platform for a wide range of biomedical applications. The fabrication process has become more elaborate in order to achieve functional structures with maximized potential. As a facile means to control the structure, here, we report a new approach to manipulate the polymerization rate and subsequent self-assembly process through regulation of the reaction viscosity. As the RNA polymerization rate has a dependence on solution viscosity, the resulting assembly, crystallization, and overall sizes of the product could be manipulated. The simple and precise control of RNA polymerization and self-assembly by reaction viscosity will provide a way to widen the utility of RNA-based materials.

Fractal LAMP: Label-Free Analysis of Fractal Precipitate for Digital Loop-Mediated Isothermal Nucleic Acid Amplification

Nucleic acid amplification assays including loop-mediated isothermal amplification (LAMP) are routinely used in diagnosing diseases and monitoring water and food quality. The results of amplification in these assays are commonly measured with an analog fluorescence readout, which requires specialized optical equipment and can lack quantitative precision. Digital analysis of amplification in small fluid compartments based on exceeding a threshold fluorescence level can enhance the quantitative precision of nucleic acid assays (i.e., digital nucleic acid amplification assays), but still requires specialized optical systems for fluorescence readout and the inclusion of a fluorescent dye. Here, we report Fractal LAMP, an automated method to detect amplified DNA in subnanoliter scale droplets following LAMP in a label-free manner. Our computer vision algorithm achieves high accuracy detecting DNA amplification in droplets by identifying LAMP byproducts that form fractal structures observable in brightfield microscopy. The capabilities of Fractal LAMP are further realized by developing a Bayesian model to estimate DNA concentrations for unknown samples and a bootstrapping method to estimate the number of droplets required to achieve target limits of detection. This digital, label-free assay has the potential to lower reagent and reader cost for nucleic acid measurement while maintaining high quantitative accuracy over 3 orders of magnitude of concentration.