Biology subjects

Vilaca, A.

Publications and source records attributed to Vilaca, A..

3 recordsLinked to original sources

bioRxiv2024

Engineered chitosan-derived nanocarrier for efficient siRNA delivery to peripheral and central neurons

Gene therapy using small interfering RNA (siRNA) holds promise for treating neurological disorders by silencing specific genes, such as the phosphatase and tensin homolog (PTEN) gene, which restricts axonal growth. Yet, delivering siRNA to neurons efficiently is challenging due to premature degradation and unspecific delivery. Chitosan-based delivery systems have shown great potential due to their well-established biocompatibility. However, their limited transfection efficiency and lack of neuronal tropism require further modification. Building on our previous successes with neuron-targeted DNA delivery using chitosan, a novel approach for siRNA delivery aimed at PTEN downregulation is proposed. This involves using thiolated trimethyl chitosan (TMCSH)-based siRNA nanoparticles functionalized with the neurotropic C-terminal fragment of the tetanus neurotoxin heavy chain (HC) for efficient delivery to both peripheral and central neurons. These polyplexes demonstrated suitable physicochemical properties, biocompatibility, and no adverse effects on neuronal electrophysiology. Diverse neuronal models, including 3D ex vivo cultures and microfluidics, confirmed polyplexes efficiency and neurospecificity. HC targeting significantly enhanced nanoparticle neuronal binding, and live cell imaging revealed five times faster retrograde transport along axons. Furthermore, siRNA delivery targeting PTEN promoted axonal outgrowth in embryonic cortical neurons. Thus, these polyplexes represent a promising platform for siRNA delivery, offering potential for clinical translation and therapeutic applications.

bioengineering↗

bioRxiv2024

Unveiling the potential of neuron-targeted dendriplexes for siRNA delivery using a PNS-CNS-on-Chip

Neurological disorders, a leading global cause of death, encompass conditions affecting the peripheral and central nervous systems (PNS and CNS, respectively). Limited axon regeneration is a significant challenge in these disorders, and it is linked to proteins like PTEN. RNA-based therapeutics, particularly siRNAs, hold potential for silencing these inhibitory pathways, but their clinical application is hindered by poor stability and cellular uptake. Our study addressed this challenge with the development of novel, fully biodegradable dendritic nanoparticles designed specifically for neuron targeting. These nanoparticles were functionalized with the neurotropic binding domain of tetanus toxin, enhancing selective neuronal targeting and cellular internalization. We demonstrated that these dendriplexes not only maintain biocompatibility and efficient siRNA delivery in neuronal cultures but also significantly enhance axonal growth, as shown in microfluidic models. In a groundbreaking PNS-CNS-on-Chip, dendriplexes exhibited effective migration from PNS to CNS neurons, highlighting their potential for targeted therapeutic delivery. This study pioneers the application of microfluidics to demonstrate the CNS targeting of dendriplexes, paving the way for innovative treatments in the field of nanomedicine.

bioengineering↗

bioRxiv2024

A miniaturised semi-dynamic in-vitro model of human digestion

Reliable in-vitro digestion models that are able to successfully replicate the conditions found in the human gastrointestinal tract (GIT) are key to assess the fate and efficiency of new formulations aimed for oral consumption. However, current in-vitro models either lack the capability to replicate crucial dynamics of digestion or require large volumes of sample/reagents, which can be scarce when working with nanomaterials under development. Here, we propose a miniaturised digestion system, a digestion-chip, based on incubation chambers integrated on a polymethylmethacrylate (PMMA) device. The digestion-chip incorporates key dynamic features of human digestion, such as gradual acidification and gradual addition of enzymes and simulated fluids in the gastric phase, and controlled gastric emptying, while maintaining low complexity and using small volumes of sample and reagents. In addition, the new approach integrates real-time automated closed-loop control of two key parameters, pH and temperature, during the two main phases of digestion (gastric and intestinal) with an accuracy down to {+/-}0.1{degrees}C and {+/-}0.2 pH points. The experimental results demonstrate that the digestion-chip successfully replicates the gold standard static digestion INFOGEST protocol and that the semi-dynamic digestion kinetics can be reliably fitted to a first kinetic order model. These devices can be easily adapted to dynamic features in an automated, sensorised, and inexpensive platform and will enable reliable, low-cost and efficient assessment of the bioaccessibility of new and expensive drugs, bioactive ingredients or nano-engineered materials aimed for oral consumption, thereby avoiding unnecessary animal testing.

bioengineering↗