Publications

The accurate spatial segregation into distinct phases within cell membranes coordinates vital biochemical processes and functionalities in living organisms. One of nature's strategies to localize reactivity is the formation of dynamic raft domains. Most raft models rely on liquid-ordered L-0 phases in a liquid-disordered L-d phase lacking correlation and remaining static, often necessitating external agents for phase separation. Here, we introduce a synthetic system of bicomponent glycodendrimersomes coassembled from Janus dendrimers and Janus glycodendrimers (JGDs), where lactose-lactose interactions exclusively drive lateral organization. This mechanism results in modulated phases across two length scales, yielding raft-like microdomains featuring nanoarrays at the nanoscale. By varying the density of lactose and molecular architecture of JGDs, the nanoarray type and size, shape, and spacing of the domains were controlled. Our findings offer insight into the potential primordial origins of rudimentary raft domains and highlight the crucial role of glycans within the glycocalyx.

JTD Keywords: Article, Artificial cells, Atomic force microscopy, Bicomponents, Bilayer, Bilayer membrane, Biochemical functionality, Biochemical process, Biological-membranes, Cell component, Cell membrane, Cellular parameters, Chemical interaction, Chemical structure, Chemistry, Cytology, Defined janus glycodendrimers, Dehydration, Dendrimer, Dendrimers, Dilution, Dimer, External agents, Fourier transform, Giant vesicles, Glycan, Glycans, Glycocalyx, Glycodendrimers, Janus dendrimer, Janus glycodendrimer, Lactose, Lateral organization, Lectin, Lipid rafts, Living organisms, Membrane damage, Membrane microdomain, Membrane microdomains, Membrane structure, Metabolism, Modulated phases, Molecule, Monomer, Nanoarrays, Oligosaccharide, Organization, Periodicity, Phase separation, Phase-separation, Phospholipids, Polysaccharide, Polysaccharides, Raft like domain, Relative humidity, Spatial segregation, Structure analysis, Sugars, Synthetic systems, Tetramer, Unclassified drug, Unilamellar vesicles, Water

Mimicking bone extracellular matrix (ECM) is paramount to develop novel biomaterials for bone tissue engineering. In this regard, the combination of integrin-binding ligands together with osteogenic peptides represents a powerful approach to recapitulate the healing microenvironment of bone. In the present work, we designed polyethylene glycol (PEG)-based hydrogels functionalized with cell instructive multifunctional biomimetic peptides (either with cyclic RGD-DWIVA or cyclic RGD-cyclic DWIVA) and cross-linked with matrix metalloproteinases (MMPs)-degradable sequences to enable dynamic enzymatic biodegradation and cell spreading and differentiation. The analysis of the intrinsic properties of the hydrogel revealed relevant mechanical properties, porosity, swelling and degradability to engineer hydrogels for bone tissue engineering. Moreover, the engineered hydrogels were able to promote human mesenchymal stem cells (MSCs) spreading and significantly improve their osteogenic differentiation. Thus, these novel hydrogels could be a promising candidate for applications in bone tissue engineering, such as acellular systems to be implanted and regenerate bone or in stem cells therapy.Copyright © 2023 Oliver-Cervelló, Martin-Gómez, Gonzalez-Garcia, Salmeron-Sanchez, Ginebra and Mas-Moruno.

JTD Keywords: biomaterials, cross-linking, dwiva, functionalization, hydrogel, integrin, kinetics, marrow stromal cells, matrices, multifunctionality, myogenic differentiation, osteogenic differentiation, regeneration, stem-cells, Biomimetic peptides, Dwiva, Functionalization, Hydrogel, Multifunctionality, Osteogenic differentiation, Poly(ethylene glycol) hydrogels

(1) Background: Restoring arm and hand function is a priority for individuals with cervical spinal cord injury (cSCI) for independence and quality of life. Transcutaneous spinal cord stimulation (tSCS) promotes the upper extremity (UE) motor function when applied at the cervical region. The aim of the study was to determine the effects of cervical tSCS, combined with an exoskeleton, on motor strength and functionality of UE in subjects with cSCI. (2) Methods: twenty-two subjects participated in the randomized mix of parallel-group and crossover clinical trial, consisting of an intervention group (n = 15; tSCS exoskeleton) and a control group (n = 14; exoskeleton). The assessment was carried out at baseline, after the last session, and two weeks after the last session. We assessed graded redefined assessment of strength, sensibility, and prehension (GRASSP), box and block test (BBT), spinal cord independence measure III (SCIM-III), maximal voluntary contraction (MVC), ASIA impairment scale (AIS), and WhoQol-Bref; (3) Results: GRASSP, BBT, SCIM III, cylindrical grip force and AIS motor score showed significant improvement in both groups (p ≤ 0.05), however, it was significantly higher in the intervention group than the control group for GRASSP strength, and GRASSP prehension ability (p ≤ 0.05); (4) Conclusion: our findings show potential advantages of the combination of cervical tSCS with an exoskeleton to optimize the outcome for UE.

JTD Keywords: arm function, cervical spinal cord injury, electrical-stimulation, functional walking, functionality, grip force, hand function, individuals, injury, motor function, reliability, robotics, spasticity, transcutaneous electrical spinal cord stimulation, upper extremity, Epidural stimulation, Transcutaneous electrical spinal cord stimulation, Upper extremity

Cell-material interactions are regulated by mimicking bone extracellular matrix on the surface of biomaterials. In this regard, reproducing the extracellular conditions that promote integrin and growth factor (GF) signaling is a major goal to trigger bone regeneration. Thus, the use of synthetic osteogenic domains derived from bone morphogenetic protein 2 (BMP-2) is gaining increasing attention, as this strategy is devoid of the clinical risks associated with this molecule. In this work, the wrist and knuckle epitopes of BMP-2 are screened to identify peptides with potential osteogenic properties. The most active sequences (the DWIVA motif and its cyclic version) are combined with the cell adhesive RGD peptide (linear and cyclic variants), to produce tailor-made biomimetic peptides presenting the bioactive cues in a chemically and geometrically defined manner. Such multifunctional peptides are next used to functionalize titanium surfaces. Biological characterization with mesenchymal stem cells demonstrates the ability of the biointerfaces to synergistically enhance cell adhesion and osteogenic differentiation. Furthermore, in vivo studies in rat calvarial defects prove the capacity of the biomimetic coatings to improve new bone formation and reduce fibrous tissue thickness. These results highlight the potential of mimicking integrin-GF signaling with synthetic peptides, without the need for exogenous GFs.© 2022 The Authors. Advanced Healthcare Materials published by Wiley-VCH GmbH.

JTD Keywords: adhesion formation, bmp-2, cell adhesions, in-vivo, integrin, mesenchymal stem-cells, morphogenetic protein-2, multifunctionality, osteoblastic differentiation, osteogenic differentiation, rgd-dwiva, rgd-peptides, titanium biofunctionalization, titanium surfaces, Animals, Biocompatible materials, Biomimetic peptides, Bone morphogenetic protein 2, Bone regeneration, Cell adhesions, Cell differentiation, Epitopes, Extracellular matrix, Integrins, Marrow stromal cells, Multifunctionality, Osteogenesis, Osteogenic differentiation, Peptides, Rats, Rgd-dwiva, Titanium, Titanium biofunctionalization

This manuscript presents portable and low cost electronic system for specific point-of-use dielectrophoresis applications. The system is composed of two main modules: a) a multiphase generator based on a Class E amplifier, which provides 4 sinusoidal signals (0°, 90°, 180°, 270°) at 1 MHz with variable output voltage up to 10 Vpp (Vm) and an output driving current of 1 A; and b) a dielectrophoresis-based microfluidic chip containing two interdigitated electrodes. The system has been validated by concentrating Escherichia Coli at 1 MHz while applying a continuous flow of 5 ?L/min. Device functionalities were verified under different conditions achieving a 83% trapping efficiency in the best case. © Springer International Publishing Switzerland 2014.

JTD Keywords: bacteria, emulsifier, enterobacter, exopolysaccharide, Bacteria, Bacteria concentrations, Biochemical engineering, Cell concentrator, Class e amplifier, Class-e amplifier, Device functionality, Dielectrophoresis, Electronic equipment, Electronics, Electrophoresis, Emulsifier, Enterobacter, Escherichia coli, Exopolysaccharide, Inter-digitated electrodes, Lab-on-a-chip (loc), Low cost, Low costs, Low-cost electronics, Medical computing, Monosaccharide, Portable device, Power amplifiers, Trapping efficiencies

Antibody-functionalized nanoparticles (NPs) are commonly used to increase the targeting selectivity toward cells of interest. At a molecular level, the number of functional antibodies on the NP surface and the density of receptors on the target cell determine the targeting interaction. To rationally develop selective NPs, the single-molecule quantitation of both parameters is highly desirable. However, techniques able to count molecules with a nanometric resolution are scarce. Here, we developed a labeling approach to quantify the number of functional cetuximabs conjugated to NPs and the expression of epidermal growth factor receptors (EGFRs) in breast cancer cells using direct stochastic optical reconstruction microscopy (dSTORM). The single-molecule resolution of dSTORM allows quantifying molecules at the nanoscale, giving a detailed insight into the distributions of individual NP ligands and cell receptors. Additionally, we predicted the fraction of accessible antibody-conjugated NPs using a geometrical model, showing that the total number exceeds the accessible number of antibodies. Finally, we correlated the NP functionality, cell receptor density, and NP uptake to identify the highest cell uptake selectivity regimes. We conclude that single-molecule functionality mapping using dSTORM provides a molecular understanding of NP targeting, aiding the rational design of selective nanomedicines.

JTD Keywords: active targeting, active targeting dstorm, antibodies, dstorm, heterogeneity, multivalency, nanomedicine, nanoparticle functionality, size, super-resolution microscopy, surface, Active targeting, Antibodies, Cell membranes, Cell receptors, Cytology, Direct stochastic optical reconstruction microscopy, Dstorm, Heterogeneity, Ligands, Medical nanotechnology, Molecules, Nanomedicine, Nanoparticle functionality, Nanoparticle targeting, Nanoparticles, Optical reconstruction, Single molecule, Stochastic systems, Stochastics, Super-resolution microscopy, Superresolution microscopy

Developing protocols to obtain intestinal epithelial monolayers that recapitulate in vivo physiology to overcome the limitations of the organoids’ closed geometry has become of great interest during the last few years. Most of the developed culture models showed physiological-relevant cell composition but did not prove self-renewing capacities. Here, we show a simple method to obtain mouse small intestine-derived epithelial monolayers organized into proliferative crypt-like domains, containing stem cells, and differentiated villus-like regions, closely resembling the in vivo cell composition and distribution. In addition, we adapted our model to a tissue culture format compatible with functional studies and prove close to physiological barrier properties of our in vitro epithelial monolayers. Thus, we have set-up a protocol to generate physiologically relevant intestinal epithelial monolayers to be employed in assays where independent access to both luminal and basolateral compartments is needed, such as drug absorption, intracellular trafficking and microbiome-epithelium interaction assays.

JTD Keywords: Mouse intestinal organoids, Adult intestinal stem cells, Matrigel, Intestinal epithelial monolayer, In vitro intestinal epithelial model, Tissue-like functionality, TEER

Strategies to inhibit initial bacterial adhesion are extremely important to prevent infection on biomaterial surfaces. However, the simultaneous attraction of desired eukaryotic cells remains a challenge for successful biomaterial-host tissue integration. Here we describe a method for the development of a trifunctional coating that repels contaminating bacteria, kills those that adhere, and promotes osteoblast adhesion. To this end, titanium surfaces were functionalized by electrodeposition of an antifouling polyethylene glycol (PEG) layer and subsequent binding of a peptidic platform with cell-adhesive and bactericidal properties. The physicochemical characterization of the samples via SEM, contact angle, FTIR and XPS analysis verified the successful binding of the PEG layer and the biomolecules, without altering the morphology and topography of the samples. PEG coatings inhibited protein adsorption and osteoblast-like (SaOS-2) attachment; however, the presence of cell adhesive domains rescued osteoblast adhesion, yielding higher values of cell attachment and spreading compared to controls (p < 0.05). Finally, the antibacterial potential of the coating was measured by live/dead assays and SEM using S. sanguinis as a model of early colonizer in oral biofilms. The presence of PEG layers significantly reduced bacterial attachment on the surfaces (p < 0.05). This antibacterial potential was further increased by the bactericidal peptide, yielding values of bacterial adhesion below 0.2% (p < 0.05). The balance between the risk of infection and the optimal osteointegration of a biomaterial is often described as “the race for the surface”, in which contaminating bacteria and host tissue cells compete to colonize the implant. In the present work, we have developed a multifunctional coating for a titanium surface that promotes the attachment and spreading of osteoblasts, while very efficiently inhibits bacterial colonization, thus holding promise for application in bone replacing applications.

JTD Keywords: Polyethylene glycol, Antibacterial, Osteointegration, Multifunctionality, Peptides, Titanium

In dentistry and orthopedics, it is well accepted that implant fixation is a major goal. However, an emerging concern is bacterial infection. Infection of metallic implants can be catastrophic and significantly reduce patient quality of life. Accordingly, in this work, we focus on multifunctional coatings to simultaneously address and mitigate both these problems. We have developed a tailor-made peptide-based chemical platform that integrates the well-known RGD cell adhesive sequence and the lactoferrin-derived LF1-11 antimicrobial peptide. The platform was covalently grafted on titanium via silanization and the functionalization process characterized by contact angle, XPS, and QCM-D. The presence of the platform statistically improved the adhesion, proliferation and mineralization of osteoblast-like cells compared to control surfaces. At the same time, colonization by representative bacterial strains was significantly reduced on the surfaces. Furthermore, the biological potency of the multifunctional platform was verified in a co-culture in vitro model. Our findings demonstrate that this multifunctional approach can be useful to functionalize biomaterials to both improve cell integration and reduce the risk of bacterial infection.

JTD Keywords: Antimicrobial peptides, Cell adhesive peptides, Multifunctionality, Osseointegration, Surface functionalization