Biology subjects

Pena-Francesch, A.

Publications and source records attributed to Pena-Francesch, A..

3 recordsLinked to original sources

bioRxiv2026

Snake Venom Fluidic Properties and Design of Venom Mimics as Rheological Surrogates

Snake venom composition and its contribution to toxic effects has been heavily researched, but there is a comparative lack of information on venoms fluidic properties and their relationship with fang morphology during the envenomation process. Understanding how venom flows through a fang can shed light on bite site dynamics and potentially explain bite symptoms. In this article we first conduct a broad comparative test of the rheological properties of venom from thirteen snake species, including multiple viperid and elapid snake species, revealing a shear-thinning non-Newtonian flow behavior in all studied species. However, we have not observed strong phylogenetic signal in venom fluidic properties, suggesting that flow properties may vary independently of evolutionary relationships between snake species. Second, we demonstrate that snake venoms fluidic properties can be modeled by other inexpensive, safe, and abundant shear-thinning surrogate fluids. We found that aqueous solutions of bovine serum albumin protein and xanthan gum are useful venom mimics, matching the rheological behavior of venoms from the studied snake species across a range of relevant shear rates. We further evaluated the performance of these snake venom mimics in a simulated venom delivery system, showing good and robust mimetic control of the flow properties as a function of applied pressure. By elucidating the fluidic properties of snake venom and providing a non-toxic, scalable surrogate fluid model to be used in further studies, we provide the biomedical, toxicology, evolutionary biology communities with a tool to study envenomation physics in an inexpensive and safe fashion. We suggest it is possible to design species-specific venom mimics that facilitate research on the biomechanics and fluid dynamics of venom delivery via snake bites, and inform the design of bioinspired puncture and injection devices.

bioengineering↗

bioRxiv2017

Squid Ring Teeth Coated Mesh Improves Abdominal Wall Repair

BackgroundHernia repair is a common surgical procedure with mesh often used. Current mesh materials have a high incidence of repair failures, due to poor tissue integration, and complications such as seroma and pain. Polypropylene (PP) mesh is the standard material in hernia repair secondary to its material durability; however, failures still approach 15%. In this first time animal study, we hypothesized that squid ring teeth (SRT), a biologically-derived high strength protein, coated polypropylene (SRT-PP) mesh, would offer enhanced tissue integration and strength compared to standard PP mesh, while proving biocompatibility for in vivo use.\n\nMaterials and methodsPolypropylene mesh was coated with SRT. Mechanical properties and cell proliferation studies of the composite mesh were performed in vitro. Rats underwent inlay mesh implantation in an anterior abdominal wall defect model. Repair was assessed clinically and radiographically, with integration evaluated by histology and mechanical testing.\n\nResultsCell proliferation was enhanced on SRT-PP composite mesh. This was corroborated by abdominal wall histology, dramatically diminished cranio-caudal mesh contraction, improved strength testing, and higher tissue failure strain following in vivo implantation. There was no increase in complications with SRT, with regard to seroma or visceral adhesion. No foreign body reactions were noted on liver histology.\n\nConclusionSRT-PP mesh showed better tissue integration than PP mesh. SRT is a high strength protein that is applied as a coating to augment mesh-tissue integration leading to improvements in abdominal wall stability with potential to reduce re-intervention for failures.

bioengineering↗

bioRxiv2016

ULTRAFAST LASER-PROBING SPECTROCOPY FOR STUDYING MOLECULAR STRUCTURE OF POLYMERIC PROTEINS

We report the development of a new technique to screen protein crystallinity quantitatively based on laser-probing spectroscopy with sub-picosecond resolution. First, we show theoretically that the temperature dependence of the refractive index of a polymeric protein is correlated to its crystallinity. Then, we performed time-domain thermo-transmission experiments on purified semi-crystalline proteins, both native and recombinant (i.e., silk and squid ring teeth), and also on intact E. coli cells bearing overexpressed recombinant protein. Our results demonstrate, for the first time, quantification of crystallinity in real time for polymeric proteins. Our approach can potentially be used for screening an ultra-large number of polymeric proteins in vivo.

biophysics↗