Recent advances of controlled drug delivery using microfluidic platforms

Small, Traceable, Endosome-Disrupting, and Bioresponsive Click Nanogels Fabricated via Microfluidics for CD44-Targeted Cytoplasmic Delivery of Therapeutic Proteins

Nanogels (NG) are among the most ideal cytoplasmic protein delivery vehicles; however, their performance is suboptimal, partly owing to relatively big size, poor cell uptake, and endosomal entrapment. Here, we developed small, traceable, endosome-disrupting, and bioresponsive hyaluronic acid NG (HA-NG) for CD44-targeted intracellular delivery of therapeutic proteins. With microfluidics and catalyst-free photo-click cross-linking, HA-NG with hydrodynamic diameters of ca. 80 and 150 nm, strong green fluorescence and efficient loading of various proteins including saporin (Sap), cytochrome C, herceptin, immunoglobulin G (IgG), and bovine serum albumin could be fabricated. Interestingly, 80 nm-sized HA-NG revealed clearly better cellular uptake than its 150 nm counterparts in both CD44-negative U87 cancer cells and CD44-positive 4T1 and MDA-MB-231 cells. Moreover, small NG exhibited accelerated endosomal escape, which was further boosted by introducing GALA, a pH-sensitive fusogenic peptide. Accordingly, Sap-loaded small and GALA-functionalized HA-NG showed the highest cytotoxicity in CD44-positive MDA-MB-231, 4T1, A549, and SMMC-7721 cancer cells. The biodistribution studies demonstrated that 80 nm-sized HA-NG displayed significantly greater tumor uptake as well as penetration in MDA-MB-231 human breast tumor xenografts than its 150 nm counterparts, whereas the introduction of GALA had no detrimental effect on tumor accumulation. Small, endosome-disrupting, and bioresponsive HA-NG with easy and controlled fabrication hold a great potential for targeted protein therapy.

Recent advances of microneedles for biomedical applications: drug delivery and beyond

The microneedle (MN), a highly efficient and versatile device, has attracted extensive scientific and industrial interests in the past decades due to prominent properties including painless penetration, low cost, excellent therapeutic efficacy, and relative safety. The robust microneedle enabling transdermal delivery has a paramount potential to create advanced functional devices with superior nature for biomedical applications. In this review, a great effort has been made to summarize the advance of microneedles including their materials and latest fabrication method, such as three-dimensional printing (3DP). Importantly, a variety of representative biomedical applications of microneedles such as disease treatment, immunobiological administration, disease diagnosis and cosmetic field, are highlighted in detail. At last, conclusions and future perspectives for development of advanced microneedles in biomedical fields have been discussed systematically. Taken together, as an emerging tool, microneedles have showed profound promise for biomedical applications.

A low-cost microfluidic platform for rapid and instrument-free detection of whooping cough

Whooping cough also called Pertussis is a highly contagious respiratory infection that affects all age populations. Given recent pertussis outbreaks, there is an urgent need for a point-of-care (POC) device for rapid diagnosis of pertussis. Herein, we report a low-cost microfluidic POC device integrated with loop-mediated isothermal amplification (LAMP) technique for the rapid and accurate diagnosis of pertussis. The 3D-printed bioanalyzer housed not only the biochip but also an in-house-developed portable and fully battery-powered heater for rapid POC detection of pertussis, without the need of external electricity. The fluorescence-based results could be rapidly visualized in about one hour by the naked eye without the need for any additional instrumentation. In addition, a simple centrifuge-free sample preparation process was optimized for the efficient lysis of pertussis samples and successfully used for direct detection of bacteria in nasopharyngeal samples. High sensitivity, with a limit of detection (LOD) of 5 DNA copies per LAMP zone, and high specificity were demonstrated. We envision that the microfluidic POC device can be used in various venues such as medical clinics, schools, and other low-resource settings for the fast detection of pertussis.

Optoregulated Drug Release from an Engineered Living Material: Self-Replenishing Drug Depots for Long-Term, Light-Regulated Delivery

On-demand and long-term delivery of drugs are common requirements in many therapeutic applications, not easy to be solved with available smart polymers for drug encapsulation. This work presents a fundamentally different concept to address such scenarios using a self-replenishing and optogenetically controlled living material. It consists of a hydrogel containing an active endotoxin-free Escherichia coli strain. The bacteria are metabolically and optogenetically engineered to secrete the antimicrobial and antitumoral drug deoxyviolacein in a light-regulated manner. The permeable hydrogel matrix sustains a viable and functional bacterial population and permits diffusion and delivery of the synthesized drug to the surrounding medium at quantities regulated by light dose. Using a focused light beam, the site for synthesis and delivery of the drug can be freely defined. The living material is shown to maintain considerable levels of drug production and release for at least 42 days. These results prove the potential and flexibility that living materials containing engineered bacteria can offer for advanced therapeutic applications.

EDEn-Electroceutical Design Environment: Ion Channel Tissue Expression Database with Small Molecule Modulators

The emerging field of bioelectricity has revealed numerous new roles for ion channels beyond the nervous system, which can be exploited for applications in regenerative medicine. Developing such biomedical interventions for birth defects, cancer, traumatic injury, and bioengineering first requires knowledge of ion channel targets expressed in tissues of interest. This information can then be used to select combinations of small molecule inhibitors and/or activators that manipulate the bioelectric state. Here, we provide an overview of electroceutical design environment (EDEn), the first bioinformatic platform that facilitates the design of such therapeutic strategies. This database includes information on ion channels and ion pumps, linked to known chemical modulators and their properties. The database also provides information about the expression levels of the ion channels in over 100 tissue types. The graphical interface allows the user to readily identify chemical entities that can alter the electrical properties of target cells and tissues.

Microfluidic assisted synthesis of PLGA drug delivery systems

Poly(lactic-co-glycolic acid) (PLGA) is a biocompatible and biodegradable polymer that recently attracted attention for use as part of drug delivery systems (DDS). In this context, there is an emerging need for a rapid, reliable and reproducible method of synthesis. Here, microfluidic systems provide great opportunities for synthesizing carriers in a tightly controlled manner and with low consumption of materials, energy and time. These miniature devices have been the focus of recent research since they can address the challenges inherent to the bulk system, e.g. low drug loading efficiency and encapsulation, broad size distribution and burst initial release. In this article, we provide an overview of current microfluidic systems used in drug delivery production, with a special focus on PLGA-based DDS. In this context, we highlight the advantages associated with the use of microchip systems in the fabrication of nanoparticles (NPs) and microparticles (MPs), e.g. in achieving complex morphologies. Furthermore, we discuss the challenges for selecting proper microfluidics for targeted DDS production in a translational setting and introduce strategies that are used to overcome microfluidics shortcomings, like low throughput for production.

Poly(lactic-co-glycolic acid) (PLGA) is a biocompatible and biodegradable polymer that recently attracted attention for use as part of drug delivery systems (DDS).

Microfluidic synthesis of PLGA/carbon quantum dot microspheres for vascular endothelial growth factor delivery

In this study, vascular endothelial growth factor (VEGF) loaded poly(d,l-lactide-co-glycolide) (PLGA) – carbon quantum dot microspheres were produced using microfluidic platforms.

A New Paradigm of Pharmaceutical Drug Delivery Systems (DDS): Challenges for Space, Time, and Shapes

Using 3D food printing with the Internet of Things (IoT) technology, patients can receive diagnoses and prescriptions from their doctors while in the comfort of their homes. The patient-specific prescription has been innovated by converging 3D food printing technology with drug delivery systems (DDSs). Quantitative drug dosages can be incorporated into the composition of food and produced in any shape within a short time. Automating food and DDSs makes promising implications for healing patients remotely, as well. Each of these aspects, along with IoT technology, have contributed to increased health care for patients, no matter their location. The quantitative discharge of vitamin C melted in water, mayonnaise, ketchup, and peanut butter has been verified using the Piston Typed Extrusion (PTE) method. Designs with different curves and shapes were repeatedly printed with a head speed of 1.6×10^-2 m/s, and it was confirmed that effective control while printing the shapes was possible. The Hagen-Poiseuille (HP) formula was utilized to simulate the overall printing time. This simulation affirmed that increasing the head speed from 1.6×10^-2 m/s to 4.0×10^-2 m/s had reduced the printing time consistently, but the time was not reduced continuously after 4.0×10^-2 m/s, depending on the materials' viscosities and how much curvature exists in the designs. The precision of printing was adjusted within 5% of the theoretical value during printing, and the IoT technology allowed printing of the materials within five minutes, regardless of the patient's location.