Biology subjects

Gallegos, A.

Publications and source records attributed to Gallegos, A..

6 recordsLinked to original sources

bioRxiv2025

Fluoxetine Delivery for Wound Treatment Through an Integrated Bioelectronic Device - Pharmacokinetic Parameters and Safety Profile in Swine

Wound infections are a significant medical challenge, often leading to chronicity or systemic infection. Selective serotonin reuptake inhibitors (SSRIs) have emerged as potential non-antibiotic candidates with demonstrated ability to limit growth and biofilm formation in Gram-negative bacteria, in addition to their pro-healing activity. Here, we compared direct delivery of the SSRI fluoxetine by topical bolus dosing to delivery from an iontophoresis bandage device with an actuator for temporally controlled drug delivery, in a porcine excisional wound model. Device delivery of fluoxetine resulted in a maximum concentration of 12.25 ng fluoxetine per mg tissue, compared to 2.926 ng/mg following bolus dosing, and tissue fluoxetine levels were higher after application using the device than after bolus dosing across the range of doses tested (p=0.0041). The half-life of fluoxetine in the wound tissue was 0.988 {+/-} 0.256 days. Fluoxetine was not detected in the pig plasma, and plasma serotonin levels were not affected by the topical application. Fluoxetine delivery using the device, but not bolus delivery, produced tissue concentrations above the minimum inhibitory concentration (MIC) for some clinically important species of bacteria. The experimental device can effectively deliver topical fluoxetine to the wound, producing higher tissue concentrations of fluoxetine at lower cumulative doses compared to bolus dosing, and with minimal risk of off-target effects. The device may simplify wound treatment by reducing the burden for daily drug application, possibly increasing adherence to a prescribed treatment regimen.

bioengineering↗

bioRxiv2024

Wireless bioelectronic device for wound healing

Wireless bioelectronic actuators have been developed to deliver targeted treatments over multiple days while continuously monitoring delivery, thereby improving wound healing. Specifically, these devices can deliver charged biomolecules such as fluoxetine cations (Flx+) and electric field (EF) in freely moving pigs. Treatments can be controlled and monitored in real time via WiFi, with options for both user-specified delivery rates and durations, as well as automated closed-loop (CL) control. The devices are engineered to handle various failure scenarios that may arise in dynamic, real-world experiments--such as communication or power interruptions--ensuring that valuable experimental data is collected with minimal disruption. The ion pump features eight drug reservoirs and channels arranged around a 20 mm diameter-wound, with a central ground electrode (0 V). When voltages above 0 V are applied to the outer channels, currents flow from the reservoirs and channels into the wound, delivering Flx+ and/or EF depending on the reservoir solution. The device records applied voltages and currents locally to a microSD card at a high sampling rate, while simultaneously transmitting real-time measurements via a local WiFi network to a wound healing algorithm running on a nearby laptop. CL control of current/delivery rate is performed by an onboard microcontroller unit (MCU) and current-source microchips, based on instructions received from the wound healing algorithm. A graphical user interface (GUI) provides intuitive user control and real-time data visualization, with support for multiple devices. In vivo studies over seven days showed that Flx+-treated wounds had a 20% lower M1/M2 macrophage ratio and 41.67% greater re-epithelialization compared to controls (standard-of-care), demonstrating the actuators potential to enhance wound healing.

biochemistry↗

bioRxiv2024

Surface Patterned Omniphobic Tiles (SPOTs): a versatile platform for scalable liquid handling

Manipulating liquids is a ubiquitous need for experiments across numerous scientific disciplines. To overcome limitations of current methods, we introduce Surface Patterned Omniphobic Tiles (SPOTs). This platform combines geometry and surface engineering, building on discontinuous wetting approaches to leverage capillarity for metering liquids. The SPOTs platform allows manipulation of hundreds to thousands of independent experiments without expensive equipment or large consumable costs. These devices can handle a wide range of liquid types and volumes (<10 nanoliters to >10 microliters) with better precision than pipetting. The platform is inexpensive and easy to fabricate, fast and intuitive to use, and cross-compatible with existing microwell plate layouts. We demonstrate how these capabilities facilitate diverse experiments including testing antibiotic combinations for synergy and antagonism, material screening of perovskites, and genotyping microbial isolates. We anticipate SPOTs will enable users from disparate domains to quickly and easily run a wide range of high-throughput experiments.

bioengineering↗

bioRxiv2023

Programmable delivery of fluoxetine via wearable bioelectronics for wound healing in vivo

The ability to deliver drugs with precise dosages at specific time points can significantly improve disease treatment while reducing side effects. Drug encapsulation for gradual delivery has opened up the doors for superior treatment regimen. To expand on this ability, programming bioelectronic devices to deliver small molecules enables ad-hoc personalized therapeutic profiles that are more complex than simple gradual release. Here, we introduce a wearable bioelectronic bandage with an integrated electrophoretic ion pump that affords on-demand drug delivery with precise dose control. Delivery of fluoxetine to wounds in mice resulted in a 27.2% decrease in the macrophage ratio (M1/M2) and a 39.9% increase in re-epithelialization, indicating a shorter inflammatory phase and faster overall healing. Programmable drug delivery using wearable bioelectronics in wounds introduces a broadly applicable strategy for the long-term delivery of a prescribed treatment regimen with minimal external intervention.

bioengineering↗

bioRxiv2023

Quantifying innervation facilitated by deep learning in wound healing

The peripheral nerves (PNs) innervate the dermis and epidermis, which have been suggested to play an important role in wound healing. Several methods to quantify skin innervation during wound healing have been reported. Those usually require multiple observers, are complex and labor-intensive, and noise/background associated with the Immunohistochemistry (IHC) images could cause quantification errors/user bias. In this study, we employed the state-of-the-art deep neural network, DnCNN, to perform pre-processing and effectively reduce the noise in the IHC images. Additionally, we utilized an automated image analysis tool, assisted by Matlab, to accurately determine the extent of skin innervation during various stages of wound healing. The 8mm wound is generated using a circular biopsy punch in the wild-type mouse. Skin samples were collected on days 3,7,10 and 15, and sections from paraffin-embedded tissues were stained against pan-neuronal marker- protein-gene-product 9.5 (PGP 9.5) antibody. On day 3 and day 7, negligible nerve fibers were present throughout the wound with few only on the lateral boundaries of the wound. On day 10, a slight increase in nerve fiber density appeared, which significantly increased on day 15. Importantly we found a positive correlation (R-2 = 0.933) between nerve fiber density and re-epithelization, suggesting an association between re-innervation and re-epithelization. These results established a quantitative time course of re-innervation in wound healing, and the automated image analysis method offers a novel and useful tool to facilitate the quantification of innervation in the skin and other tissues.

molecular biology↗

bioRxiv2022

Multi-lingual multi-platform investigations of online trade in jaguar parts

We conducted research to understand online trade in jaguar parts and develop tools of utility for jaguars and other species. Our research took place to identify potential trade across 31 online platforms in Spanish, Portuguese, English, Dutch, French, Chinese, and Vietnamese. We identified 230 posts from between 2009 and 2019. We screened the images of animal parts shown in search results to verify if from jaguar; 71 posts on 12 different platforms in four languages were accompanied by images identified as definitely jaguar, including a total of 125 jaguar parts (50.7% posts in Spanish, 25.4% Portuguese, 22.5% Chinese and 1.4% French). Search effort varied among languages due to staff availability. Standardizing for effort across languages by dividing number of posts advertising jaguars by search time and number individual searches completed via term/platform combinations, the adjusted rankings of posts were: Portuguese #1, Chinese 2 (time) & 3 (searches), Spanish 3 & 4; French 5 & 4; English 5 & 2, and Dutch 6. Teeth were most common; 156 posts offered at least 367 apparent teeth. From these, 95 teeth were assessed as definitely jaguar; 71 jaguar teeth could be linked to a location, with the majority of the 71 offered for sale from Mexico, China, Bolivia, and Brazil (26.8, 25.4, 16.9, and 12.7% respectively). Ranking of number of teeth was Mexico (19), China (18), Bolivia (12), Brazil (9), Peru/Ecuador (most accurate probable location) (8), Venezuela (3), Guadeloupe (1), and Uruguay (1). The second most traded item, skins and derivative items were only identified from Latin America: Brazil (7), was followed by Peru (6), Bolivia (3), Mexico (2 and 1 skin piece), and Nicaragua and Venezuela (1 each). Whether by number of posts or pieces, the ranking of parts was teeth, skins/pieces of skins, heads, and bodies. Our research presents a snapshot of online jaguar trade and methods that may have utility for many species now traded online. Our research took place within a longer-term project to assist law enforcement in host countries to better identify potential illegal trade online, with research findings informing hubs in Latin America for building such capacity.

ecology↗