Engineering and Characterization of a Biomimetic Microchip for Differentiating Mouse Adipocytes in a 3D Microenvironment.

Although two-dimensional (2D) cell cultures are the standard in cell research, one pivotal disadvantage is the lack of cell-cell and cell-extracellular matrix (ECM) signaling in the culture milieu. However, such signals occur in three-dimensional (3D) in vivo environments and are essential for cell differentiation, proliferation, and a range of cellular functions. In this study, we developed a microfluidic device to proliferate and differentiate functional adipose tissue and adipocytes by utilizing 3D cell culture technology. This device was used to generate a tissue-specific 3D microenvironment to differentiate 3T3-L1 preadipocytes into either visceral white adipocytes using visceral adipose tissue (VAT) or subcutaneous white adipose tissue (SAT). The microchip has been tested and validated by functional assessments including cell morphology, inflammatory response to a lipopolysaccharide (LPS) challenge, GLUT4 tracking, and gene expression analyses. The biomimetic microfluidic chip is expected to mimic functional adipose tissues that can replace 2D cell cultures and allow for more accurate analysis of adipose tissue physiology.

Nanoemulsion delivery systems for enhanced efficacy of antimicrobials and essential oils.

The ever-growing threat of new and existing infectious diseases in combination with antimicrobial resistance requires the need for innovative and effective forms of drug delivery. Optimal drug delivery systems for existing and newly developed antimicrobials can enhance drug bioavailability, enable site-specific drug targeting, and overcome current limitations of drug formulations such as short elimination half-lives, poor drug solubility, and undesirable side effects. Nanoemulsions (NE) consist of nanometer-sized droplets stabilized by emulsifiers and are typically more stable and permeable due to their smaller particle sizes and higher surface area compared to conventional emulsions. NE have been identified as a promising means of antimicrobial delivery due to their intrinsic antimicrobial properties, ability to increase drug solubility, stability, bioavailability, organ and cellular targeting potentials, capability of targeting biofilms, and potential to overcome antimicrobial resistance. Herein, we discuss non-drug loaded essential oil-based NE that can confer antimicrobial actions through predominantly physical or biochemical mechanisms without drug payloads. We also describe drug-loaded NE for enhanced antimicrobial efficacy by augmenting the potency of existing antimicrobials. We highlight the versatility of NE to be administered through multiple different routes (oral, parenteral, dermal, transdermal, pulmonary, nasal, ocular, and rectal). We summarize recent advances in the clinical translation of antimicrobial NE and shed light on future development of effective antimicrobial therapy to combat infectious diseases.

Design and Development of a Three-Dimensionally Printed Microscope Mask Alignment Adapter for the Fabrication of Multilayer Microfluidic Devices.

This project aims to develop an easy-to-use and cost-effective platform for the fabrication of precise, multilayer microfluidic devices, which typically can only be achieved using costly equipment in a clean room setting. The key part of the platform is a three dimensionally (3D) printed microscope mask alignment adapter (MMAA) compatible with regular optical microscopes and ultraviolet (UV) light exposure systems. The overall process of creating the device has been vastly simplified because of the work done to optimize the device design. The process entails finding the proper dimensions for the equipment available in the laboratory and 3D-printing the MMAA with the optimized specifications. Experimental results show that the optimized MMAA designed and manufactured by 3D printing performs well with a common microscope and light exposure system. Using a master mold prepared by the 3D-printed MMAA, the resulting microfluidic devices with multilayered structures contain alignment errors of <10 µm, which is sufficient for common microchips. Although human error through transportation of the device to the UV light exposure system can cause larger fabrication errors, the minimal errors achieved in this study are attainable with practice and care. Furthermore, the MMAA can be customized to fit any microscope and UV exposure system by making changes to the modeling file in the 3D printing system. This project provides smaller laboratories with a useful research tool as it only requires the use of equipment that is typically already available to laboratories that produce and use microfluidic devices. The following detailed protocol outlines the design and 3D printing process for the MMAA. In addition, the steps for procuring a multilayer master mold using the MMAA and producing poly(dimethylsiloxane) (PDMS) microfluidic chips is also described herein.