Insereixen material genètic al nucli cel·lular per a teràpia gènica amb nanodiscs

Investigadors de la UAB han aconseguit encapsular material genètic i alliberar-lo directament dins el nucli de les cèl·lules, per tal de dur a terme teràpia gènica, mitjançant partícules amb forma de disc de la grandària de només un pocs nanòmetres. Els nanodiscs, tal i com els han batejat els investigadors, travessen ràpidament l'interior de la cèl·lula i es concentren en el nucli, de manera que incrementarien l'eficiència del procés de transferència genètica.Investigadores de la UAB han conseguido encapsular material genético y liberarlo directamente dentro del núcleo de las células, para llevar a cabo terapia génica, mediante partículas con forma de disco del tamaño de sólo unos pocos nanómetros. Los nanodiscos, tal y como los han bautizado los investigadores, atraviesan rápidamente el interior de la célula y se concentran en el núcleo, de manera que incrementarían la eficiencia del proceso de transferencia genética.Researchers at UAB have discovered a novel gene therapy method using particles measuring only a few nanometres which encapsulate genetic material and introduce themselves directly into the cell nucleus. The nanodisks, as researchers have named the particles, travel rapidly to the interior of the cell until reaching the nucleus, thus increasing the efficiency of the gene transfer process

Targeting in Cancer Therapies

Drug developers recruit and combine principles, procedures and strategies from chemistry, pharmacology, nanotechnology and biotechnology, focusing on the generation of functional vehicles as nano-carriers of drugs for improved stability and enhanced intracellular delivery.[...

Microbial factories for recombinant pharmaceuticals

Most of the hosts used to produce the 151 recombinant pharmaceuticals so far approved for human use by the Food and Drug Administration (FDA) and/or by the European Medicines Agency (EMEA) are microbial cells, either bacteria or yeast. This fact indicates that despite the diverse bottlenecks and obstacles that microbial systems pose to the efficient production of functional mammalian proteins, namely lack or unconventional post-translational modifications, proteolytic instability, poor solubility and activation of cell stress responses, among others, they represent convenient and powerful tools for recombinant protein production. The entering into the market of a progressively increasing number of protein drugs produced in non-microbial systems has not impaired the development of products obtained in microbial cells, proving the robustness of the microbial set of cellular systems (so far Escherichia coli and Saccharomyces cerevisae) developed for protein drug production. We summarize here the nature, properties and applications of all those pharmaceuticals and the relevant features of the current and potential producing hosts, in a comparative wa

CXCR4(+)-targeted protein nanoparticles produced in the food-grade bacterium Lactococcus lactis

Lactococcus lactis is a Gram-positive (endotoxin-free) food-grade bacteria exploited as alternative to Escherichia coli for recombinant protein production. We have explored here for the first time the ability of this platform as producer of complex, self-assembling protein materials. Materials & methods: Biophysical properties, cell penetrability and in vivo biodistribution upon systemic administration of tumor-targeted protein nanoparticles produced in L. lactis have been compared with the equivalent material produced in E. coli. Results: Protein nanoparticles have been efficiently produced in L. lactis, showing the desired size, internalization properties and biodistribution. Conclusion: In vitro and in vivo data confirm the potential and robustness of the production platform, pointing out L. lactis as a fascinating cell factory for the biofabrication of protein materials intended for therapeutic applications.Award-winningPostprint (published version

Endosomal escape of protein nanoparticles engineered through humanized histidine-rich peptides

Altres ajuts: EU COST Action CA 17140. AV received an ICREA ACADEMIA awardPoly-histidine peptides such as H6 (HHHHHH) are used in protein biotechnologies as purification tags, protein-assembling agents and endosomal-escape entities. The pleiotropic properties of such peptides make them appealing to design protein-based smart materials or nanoparticles for imaging or drug delivery to be produced in form of recombinant proteins. However, the clinical applicability of H6-tagged proteins is restricted by the potential immunogenicity of these segments. In this study, we have explored several humanized histidine-rich peptides in tumor-targeted modular proteins, which can specifically bind and be internalized by the target cells through the tumoral marker CXCR4. We were particularly interested in exploring how protein purification, self-assembling and endosomal escape perform in proteins containing the variant histidine-rich tags. Among the tested candidates, the peptide H5E (HEHEHEHEH) is promising as a good promoter of endosomal escape of the associated full-length protein upon endosomal internalization. The numerical modelling of cell penetration and endosomal escape of the tested proteins has revealed a negative relationship between the amount of protein internalized into target cells and the efficiency of cytoplasmic release. This fact demonstrates that the His-mediated, proton sponge-based endosomal escape saturates at moderate amounts of internalized protein, a fact that might be critical for the design of protein materials for cytosolic molecular delivery

Focusing in bioproduction science

As in other Biotechnological fields, the microbial production of recombinant proteins and other biomolecules can be approached from multiple angles through the help of diverse technologies of increasing complexity. To better reach all the specialized niches in bioproduction, Microbial Cell Factories is now inviting authors to prepare concise Reviews (eventually miniReviews), covering relevant areas that deserve specific and highly focused attention. By the publication of such contributions, the journal will promote the revision of new insights around the Cell Factory concept in a highly comprehensive way, in molecular, cellular and environmental contexts

Towards Protein-Based Viral Mimetics for Cancer Therapies

High resistance and recurrence rates, along with elevated drug clearance, compel the use of maximum tolerated drug doses in cancer therapy, resulting in high-grade toxicities and limited clinical applicability. Promoting active drug accumulation in tumor tissues would minimize such issues and improve therapeutic outcomes. A new class of therapeutic drugs suitable for the task has emerged based on the concept of virus-mimetic nanocarriers, or 'artificial viruses.' Among the spectrum of materials under exploration in nanocarrier research, proteins offer unparalleled structural and functional versatility for designing viruslike molecular vehicles. By exhibiting 'smart' functions and biomimetic traits, protein-based nanocarriers will be a step ahead of the conventional drug-protein conjugates already in the clinics in ensuring efficient delivery of passenger antitumor drugs

Effect of the DnaK chaperone on the conformational quality of JCV VP1 virus-like particles produced in Escherichia coli

Altres ajuts: CIBER de Bioingeniería, Biomateriales y Nanomedicina ; VI National R&D&i Plan 2008-2011 ; Iniciativa Ingenio 2010 ; Consolider Program ; CIBER Actions ; Instituto de Salud Carlos III ; European Regional Development FundProtein nanoparticles such as virus-like particles (VLPs) can be obtained by recombinant protein production of viral capsid proteins and spontaneous self-assembling in cell factories. Contrarily to infective viral particles, VLPs lack infective viral genome while retaining important viral properties like cellular tropism and intracellular delivery of internalized molecules. These properties make VLPs promising and fully biocompatible nanovehicles for drug delivery. VLPs of human JC virus (hJCV) VP1 capsid protein produced in Escherichia coli elicit variable hemagglutination properties when incubated at different NaCl concentrations and pH conditions, being optimal at 200 mM NaCl and at pH range between 5.8 and 7.5. In addition, the presence or absence of chaperone DnaK in E. coli cells influence the solubility of recombinant VP1 and the conformational quality of this protein in the VLPs. The hemagglutination ability of hJCV VP1 VLPs contained in E. coli cell extracts can be modulated by buffer composition in the hemagglutination assay. It has been also determined that the production of recombinant hJCV VP1 in E. coli is favored by the absence of chaperone DnaK as observed by Western Blot analysis in different E. coli genetic backgrounds, indicating a proteolysis targeting role for DnaK. However, solubility is highly compromised in a DnaK(-) E. coli strain suggesting an important role of this chaperone in reduction of protein aggregates. Finally, hemagglutination efficiency of recombinant VP1 is directly related to the presence of DnaK in the producing cells