With the resurgence of illnesses, such as measles, it is of utmost importance that a high percentage of the local and global population be vaccinated. Diseases, such as measles, HepB, Hib, and others, are suppressed when 93%–95% of a population has been vaccinated against them, generating herd immunity. Lack of vaccination can lead to lifelong consequences. Barriers to vaccination include costs, lack of healthcare worker knowledge, reliance on cold chain storage, age, and personal beliefs. Vaccinations are usually administered as subcutaneous or intramuscular injections, though some oral vaccines exist. The use of intradermal or intramuscular electroporation (ID-EP and IM-EP) as an adjuvant has demonstrated benefits over traditional vaccination methods, while also having some issues, which require careful consideration. Issues for consideration include a lack of standardized equipment and pulsing protocols while benefits include dose sparing, long-term immunogenicity, and higher titer levels after a single dose compared to the gold standard. ID-EP has been shown to have better transfection rates over IM-EP, while IM-EP has demonstrated faster seroconversion rates (SRs) over IM injection alone. Improvements such as standardizing equipment with larger injection volumes, multiple EP site locations and/or disposable, predosed, lyophilized vaccine cartridges could contribute to more rapid deployment of vaccines without relying on cold chain storage and trained healthcare workers, at a reduced cost while still providing adequate levels of immunity against disease.
Ex-vivo liver perfusion (EVLP) is an ideal platform to study liver disease, therapeutic interventions, and pharmacokinetic properties of drugs without any patient risk. Rat livers are an ideal model for EVLP due to less organ quality variability, ease of hepatectomy, well-defined molecular pathways, and relatively low costs compared to large animal or human perfusions. However, the major limitation with rat liver normothermic machine perfusion (NMP) is maintaining physiologic liver function on an ex-vivo machine perfusion system. To address this need, our research demonstrates 24-hour EVLP in rats under normothermic conditions. Early (6 hour) perfusate transaminase levels and oxygen consumption of the liver graft are shown to be good markers of perfusion success and correlate with viable 24-hour post-perfusion histology. Finally, we address overcoming challenges in long-term rat liver perfusions such as rising intrahepatic pressures and contamination, and offer future directions necessary to build upon our work.
In vitro tools, which can enable development of models that replicate the cell microenvironment associated with complex diseases such as osteoarthritis (OA), are critically needed. In OA, catabolic and inflammatory processes orchestrated by multiple cell types lead to the eventual destruction of articular cartilage. To address this need, our group developed a device that will enable investigation of complex cell systems. Our stackable tissue culture insert was fabricated and characterized with respect to biocompatibility, ease of use, and potential for tissue culture applications. The stackable tissue culture inserts can be easily modified, fabricated, and assembled into commercially available multi-well plates. In vitro studies conducted with three different cell types demonstrated high cell viability and functional secretion when cultured in the stackable inserts. Furthermore, synergistic effects when the three cell types were cultured together were observed. This demonstrates the need to more fully interrogate in vitro culture systems, and this stackable insert can provide a tool to fill the current technological void to do so.
Pulsed electric field (PEF) is an emerging technology for biomass processing and fractionation by electroporation of cell membrane. Nevertheless, PEF technology and devices require tailoring and adaptation for each specific type of biomass. Such an optimization requires convenient and adaptable laboratory systems, which will enable both electrical and mechanical parameters determination before process upscaling. In this work, we report on the design and development of a laboratory PEF system that allows applying for up to 4[Formula: see text]kV, 1[Formula: see text]kA pulses with 1–100[Formula: see text][Formula: see text]s and total power dissipation of 20[Formula: see text]W and up to 25[Formula: see text]kg of mechanical load. The design of an asymmetric voltage multiplying circuit allows for controlling pulse parameters for each pulse in series. Such an approach enables precise adaptation of PEF to the changing conductivity of the biomass, minimizing the total invested energy in the process. The system was tested on highly conductive marine macroalgae Ulva sp, a promising but challenging feedstock for the biorefinery. This work provides a design of an adaptable PEF device, important for biomass processing with electroporation.
Microfluidic devices are constructed from polydimethylsiloxane (PDMS) due to their biocompatibility, fabrication ease, well-established protocols, and simplicity. PDMS-based microfluidic devices are constructed by (i) applying liquid PDMS to a negative mold (usually a silicon or 3D-printed mold) and (ii) curing the PDMS with heat exposure over a set time period. Unreacted resin monomers in 3D-printed molds prevent PDMS from fully curing, resulting in improper channel formation in PDMS and reducing the PDMS device’s efficacy. An in-house protocol that uses SU-8 as a “non-stick” coating on 3D-printed molds facilitates the successful casting of PDMS. Contact angle, surface profile, optical profile, and force testing prove that PDMS cast from SU-8-treated molds resembles pristine PDMS, unlike PDMS cast from untreated molds. Further, this method is generalized to commercial 3D prints using different 3D printing resins. To demonstrate this technique’s viability in microfluidic devices, a microfluidic tree using PDMS from treated 3D prints shows vibrant colors and clear lines. This is absent from an untreated PDMS.
