Introduction: Controlled delivery of therapeutic molecules in a localized manner has become an area of interest due to its potential to reduce drug exposure to healthy tissues and consequently to minimize undesirable side effects. We have recently introduced novel cell-penetrating vehicles by immobilizing the antimicrobial peptide Buforin II (BUF-II) on magnetite nanoparticles (MPNPs). Despite the potent translocating abilities of such nanobioconjugates, they failed to preserve the antimicrobial activity of native BUF-II. In this work, we explored immobilization on MNPs with the aid of polymer surface spacers, which has been considered as an attractive alternative for the highly efficient conjugation of various biomolecules. Methods: Here, we immobilized BUF-II on polyetheramine-modified magnetite nanoparticles to preserve its structural integrity. As a result, for the obtained nanobioconjugates the lost antimicrobial activity against gram-positive and gram-negative bacteria was only 50% with respect to the native BUF-II. The nanobioconjugates were also characterized via FTIR, DLS, TEM, and TGA. Delivery on THP-1, HaCaT, HFF, and Escherichia coli cells was conducted to confirm capability for cell membrane translocation. Results: Colocalization with Lysotracker showed an endosomal escape efficiency of about 73∓12% in THP-1 cells. Avoidance of endocytic pathways of internalization was qualitatively confirmed by a delivery assay at low temperature. Nuclear penetration of the nanobioconjugates was corroborated via confocal microscopy and showed high biocompatibility as demonstrated by hemolysis levels below 5% and acute cytotoxicity of around 15%. Conclusion: The obtained nanobioconjugates were capable of translocating the cell membrane and nuclei of different normal and cancerous cell lines without significantly decreasing viability. This makes the vehicle addressable for a number of applications ranging from antimicrobial topical treatments to the delivery of nucleotides and therapeutic molecules with difficulties to bypass cell membranes.

Introduction: One of the major challenges of modern pharmacology is the development of systems for the delivery of therapeutic molecules in a controlled and localized manner. One strategy is to use nanostructured supports, which are well suited to carry a large number of molecules on a per mass basis. A major challenge for these supports is, however, their limited ability to bypass the cell membrane. Recent studies propose that to overcome this issue, potent translocating cell-penetrating peptides (CPPs) can be conjugated to their surfaces. Methods: Here, we conjugated the antimicrobial CPP buforin II (BUF2) to the surface of magnetite nanoparticles to enhance their cell penetration. Conjugates were characterized via Fourier transform infrared spectroscopy, dynamic light scattering, and thermogravimetric analysis, and their biocompatibility was corroborated. The conjugates were delivered in both bacterial and mammalian cells demonstrating the intracellular inclusion in THP-1 cells for the first time. Results: Despite the promising outcome, our studies showed that the obtained conjugates failed to maintain the native antimicrobial activity of BUF2. We hypothesize that to overcome this issue, a flexible linker can be inserted prior to conjugation. Conclusion: Our study highlights the potential of BUF2-magnetite conjugates as cell-penetrating vehicles for the targeted delivery of pharmacological agents. This provides support for the idea of a promising combined drug delivery and antimicrobial peptide therapy.

Non-centrifugal cane sugar (NCS) is a traditional sweetener in most sugarcane regions of the world. In Colombia, this product has a socio-economic importance due to the extensive cultivation area and the high consumption rate per capita. NCS traditional processing involves consecutive stages of thermal processing that begin with juice extraction, clarification, evaporation, and finish with syrup crystallization into a solid commercial product, identified as NCS. Sugarcane is known to have a natural content of polyphenols, amino acids, vitamins, minerals, and complex sugars, some of which are reported as antioxidant and antiproliferative agents thought to be responsible for the product’s bioactive profile. There is evidence to suggest that traditional thermal processing to obtain NCS leads to a considerable decrease in the contents of these bioactive compounds, mainly due to uncontrolled process variables such as temperature. Accordingly, the aim of this study was to assess and compare the bioactivity of sugarcane (SC) derivatives produced under controlled thermal conditions versus the traditional method. To achieve this goal, we evaluated the cytotoxic, antioxidant, and neuroprotective effects of varying concentrations of SC derivatives in an in vitro induced Parkinson’s model. Results demonstrate non-cytotoxic activity on the cellular model by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and LDH assays, even at the highest tested concentration of 8 mg/mL, for all SC derivatives. The effect of SC derivatives on the induced oxidative stress model showed a biological reversion and recovering effect of the mitochondrial membrane potential and a halting of the progress into the early apoptosis phase. In conclusion, we demonstrated that the bioactive compounds present in SC derivatives obtained by a process under controlled temperature conditions are largely preserved, and even their biological activities are enhanced compared with SC derivatives obtained by the traditional thermal evaporation of SC-juice.

Oil palm plantation establishment in Colombia has the potential to impact Chagas disease transmission by increasing the distribution range of Rhodnius prolixus. In fact, previous studies have reported Trypanosoma cruzi natural infection in R. prolixus captured in oil palms (Elaeis guineensis) in the Orinoco region, Colombia. The aim of this study is to understand T. cruzi infection in vectors in oil palm plantations relative to community composition and host dietary specialization by analyzing vector blood meals and comparing these results to vectors captured in a native palm tree species, Attalea butyracea. Rhodnius prolixus nymphs (n = 316) were collected from A. butyracea and E. guineensis palms in Tauramena, Casanare, Colombia. Vector blood meals from these nymphs were determined by amplifying and sequencing a vertebrate-specific 12S rRNA gene fragment. Eighteen vertebrate species were identified and pigs (Sus scrofa) made up the highest proportion of blood meals in both habitats, followed by house mouse (Mus musculus) and opossum (Didelphis marsupialis). Individual bugs feeding only from generalist mammal species had the highest predicted vector infection rate, suggesting that generalist mammalian species are more competent hosts for T. cruzi infection . Oil palm plantations and A. butyracea palms found in altered areas provide a similar quality habitat for R. prolixus populations in terms of blood meal availability. Both habitats showed similarities in vector infection rate and potential host species, representing a single T. cruzi transmission scenario at the introduced oil palm plantation and native Attalea palm interface.

Currently available small diameter vascular conduits present several long-term limitations, which has prevented their full clinical implementation. Commercially available vascular grafts show no regenerative capabilities and eventually require surgical replacement; therefore, it is of great interest to develop alternative regenerative vascular grafts (RVG). Decellularized Small Intestinal Submucosa (SIS) is an attractive material for RVG, however, the evaluation of the performance of these grafts is challenging due to the absence of devices that mimic the conditions found in vivo. Thereby, the objective of this study is to design, manufacture and validate in silico and in vitro, a novel fluidic system for the evaluation of human umbilical vein endothelial cells (HUVECs) proliferation on SIS-based RVG under dynamical conditions. Our perfusion and rotational fluidic system was designed in Autodesk Inventor 2018. In silico Computational Fluid Dynamics (CFD) validation of the system was carried out using Ansys Fluent software from ANSYS, Inc for dynamical conditions of a pulsatile pressure function measured experimentally over a rigid wall model. Mechanical and biological parameters such as flow regime, pressure gradient, wall shear stress (WSS), sterility and indirect cell viability (MTT assay) were also evaluated. Cell adhesion was confirmed by SEM imaging. The fluid flow regime within the system remains laminar. The system maintained sterility and showed low cytotoxicity levels. HUVECs were successfully cultured on SIS-based RVG under both perfusion and rotation conditions. In silico analysis agreed well with our experimental and theoretical results, and with recent in vitro and in vivo reports for WSS. The system presented is a tool for evaluating RVG and represents an alternative to develop new methods and protocols for a more comprehensive study of regenerative cardiovascular devices.

The lack of success of small diameter vascular grafts (<;6 mm) has driven biomedical engineers to develop multiple strategies for their improvement. One of the most promising proposals involves the formation of a healthy and uniform endothelial layer. The early formation of this tissue on the lumen of the graft prevents thrombosis and excessive proliferation of smooth muscle cells, which can lead to intimal hyperplasia. Based on this theory, the Biomedical Engineering Group at Universidad de los Andes (GIB) is currently working to develop a smalldiameter vascular graft made of porcine intestinal submucosa (SIS) capable of promoting endothelial cell adhesion. With this purpose in mind, it is necessary to study the adhesion of endothelial cells to the biomaterial not only in a static cell culture but also under dynamic conditions, which can better simulate the cell's physiological environment in vivo. This project develops a methodology to implant cells in cardiovascular grafts under perfusion conditions in vitro, through the design of a bioreactor and the standardization of a static cell culture protocol on SIS sheets and a dynamic culture protocol on SIS grafts.