Publications

Oncolytic adenoviruses are used as agents for the treatment of cancer. However, their potential is limited due to the high seroprevalence of anti-adenovirus neutralizing antibodies (nAbs) within the population and the rapid liver sequestration when systemically administered. To overcome these challenges, we explored using nanoparticle formulation to boost the efficacy of systemic oncolytic adenovirus administration. Methods: Adenovirus were conjugated with PEGylated oligopeptide-modified poly(β-amino ester)s (OM-pBAEs). The resulting coated viral formulation was characterized in terms of surface charge, size, aggregation state and morphology and tested for anti-adenovirus nAbs evasion and activity in cancer cells. In vivo pharmacokinetics, biodistribution, tumor targeting, and immunogenicity studies were performed. The antitumor efficacy of the oncolytic adenovirus AdNuPARmE1A coated with OM-pBAEs (SAG101) in the presence of nAbs was evaluated in pancreatic ductal adenocarcinoma (PDAC) mouse models. Toxicity of the coated formulation was analyzed in vivo in immunocompetent mice. Results: OM-pBAEs conjugated to adenovirus and generated discrete nanoparticles with a neutral charge and an optimal size. The polymeric coating with the reporter AdGFPLuc (CPEG) showed enhanced transduction and evasion of antibody neutralization in vitro. Moreover, systemic intravenous administration of the formulation showed improved blood circulation and reduced liver sequestration, substantially avoiding activation of nAb production. OM-pBAEs coating of the oncolytic adenovirus AdNuPARmE1A (SAG101) improved its oncolytic activity in vitro and enhanced antitumor efficacy in PDAC mouse models. The coated formulation protected virions from neutralization by nAbs, as antitumor efficacy was preserved in their presence but was completely lost in mice that received the non-formulated AdNuPARmE1A. Finally, coated-AdNuPARmE1A showed reduced toxicity when high doses of the formulation were administered. Conclusions: The developed technology represents a promising improvement for future clinical cancer therapy using oncolytic adenoviruses.

JTD Keywords: Oncolytic adenovirus, Pancreatic cancer, Poly(β-amino ester)s, Polymer-coated viral vectors, Systemic delivery

The poor rehabilitation success rate, including the cases of ineffective and detrimental adaptations, make stroke a leading cause of disability. Thus, it is essential to recognize the mechanisms driving healthy motor recovery to improve such rate. Stroke alters the Synergy Architecture (SA), the modular muscle control system. So SA analysis may constitute a powerful tool to design and assess rehabilitation procedures. However, current impairment scales do not consider the patient's neuromuscular state. To gain insights into this hypothesis, we recorded multiple myoelectric signals from upper-limb muscles, in healthy subjects, while executing a set of common rehabilitation exercises. We found that SA reveals optimized motor control strategies and the positive effects of the use of visual feedback (VF) on motor control. Furthermore we demonstrate that the right and left arm's SA share the basic structure within the same subject, so we propose using the unaffected limb's SA as a reference motion pattern to be reached through rehabilitation.

JTD Keywords: Bars, Electromyography, Motor drives, Neuromuscular, Vectors, Visualization

Antimicrobial peptide drugs are increasingly attractive therapeutic agents as their roles in physiopathological processes are being unraveled and because the development of recombinant DNA technology has made them economically affordable in large amounts and high purity. However, due to lack of specificity regarding the target cells, difficulty in attaining them, or reduced half-lives, most current administration methods require high doses. On the other hand, reduced specificity of toxic drugs demands low concentrations to minimize undesirable side-effects, thus incurring the risk of having sublethal amounts which favour the appearance of resistant microbial strains. In this scenario, targeted delivery can fulfill the objective of achieving the intake of total quantities sufficiently low to be innocuous for the patient but that locally are high enough to be lethal for the infectious agent. One of the major advances in recent years has been the size reduction of drug carriers that have dimensions in the nanometer scale and thus are much smaller than -and capable of being internalized by- many types of cells. Among the different types of potential antimicrobial peptide-encapsulating structures reviewed here are liposomes, dendritic polymers, solid core nanoparticles, carbon nanotubes, and DNA cages. These nanoparticulate systems can be functionalized with a plethora of biomolecules providing specificity of binding to particular cell types or locations; as examples of these targeting elements we will present antibodies, DNA aptamers, cell-penetrating peptides, and carbohydrates. Multifunctional Trojan horse-like nanovessels can be engineered by choosing the adequate peptide content, encapsulating structure, and targeting moiety for each particular application.

JTD Keywords: Antibodies, Aptamers, Dendrimers, Liposomes, Nanomedicine, Nanoparticles, Nanovectors, Targeting

The roles of different ribonucleotide reductases (RNRs) in bacterial pathogenesis have not been studied systematically. In this work we analyzed the importance of the different Pseudomonas aeruginosa RNRs in pathogenesis using the Drosophila melanogaster host-pathogen interaction model. P. aeruginosa codes for three different RNRs with different environmental requirements. Class II and III RNR chromosomal mutants exhibited reduced virulence in this model. Translational reporter fusions of RNR gene nrdA, nrdJ, or nrdD to the green fluorescent protein were constructed to measure the expression of each class during the infection process. Analysis of the P. aeruginosa infection by flow cytometry revealed increased expression of nrdJ and nrdD and decreased nrdA expression during the infection process. Expression of each RNR class fits with the pathogenicities of the chromosomal deletion mutants. An extended understanding of the pathogenicity and physiology of P. aeruginosa will be important for the development of novel drugs against infections in cystic fibrosis patients.

JTD Keywords: Broad-host-range, Anaerobic growth, Drosophila-melanogaster, Bacterial biofilms, Escherichia-coli, Cystic-fibrosis, Model host, Virulence, Promoter, Vectors