RESUMO
Bactofection offers a gene delivery option particularly useful in the context of immune modulation. The bacterial host naturally attracts recognition and cellular uptake by antigen presenting cells (APCs) as the initial step in triggering an immune response. Moreover, depending on the bacterial vector, molecular biology tools are available to influence and/or overcome additional steps and barriers to effective antigen presentation. In this work, molecular engineering was applied using Escherichia coli as a bactofection vector. In particular, the bacteriophage ΦX174 lysis E (LyE) gene was designed for variable expression across strains containing different levels of lysteriolysin O (LLO). The objective was to generate a bacterial vector with improved attenuation and delivery characteristics. The resulting strains exhibited enhanced gene and protein release and inducible cellular death. In addition, the new vectors demonstrated improved gene delivery and cytotoxicity profiles to RAW264.7 macrophage APCs.
Assuntos
Bacteriófagos/metabolismo , Escherichia coli/genética , Animais , Linhagem Celular , Terapia Genética , Vetores Genéticos/genética , CamundongosRESUMO
Both steelmaking via an electric arc furnace and manufacturing of portland cement are energy-intensive and resource-exploiting processes, with great amounts of carbon dioxide (CO2) emission and alkaline solid waste generation. In fact, most CO2 capture and storage technologies are currently too expensive to be widely applied in industries. Moreover, proper stabilization prior to utilization of electric arc furnace slag are still challenging due to its high alkalinity, heavy metal leaching potentials and volume instability. Here we deploy an integrated approach to mineralizing flue gas CO2 using electric arc furnace slag while utilizing the reacted product as supplementary cementitious materials to establish a waste-to-resource supply chain toward a circular economy. We found that the flue gas CO2 was rapidly mineralized into calcite precipitates using electric arc furnace slag. The carbonated slag can be successfully utilized as green construction materials in blended cement mortar. By this modulus, the global CO2 reduction potential using iron and steel slags was estimated to be ~138 million tons per year.
RESUMO
Given the rise of antibiotic resistant microbes, genetic vaccination is a promising prophylactic strategy that enables rapid design and manufacture. Facilitating this process is the choice of vector, which is often situationally-specific and limited in engineering capacity. Furthermore, these shortcomings are usually tied to an incomplete understanding of the structure-function relationships driving vector-mediated gene delivery. Building upon our initial report of a hybrid bacterial-biomaterial gene delivery vector, a comprehensive structure-function assessment was completed using a class of mannosylated poly(beta-amino esters). Through a top-down screening methodology, an ideal polymer was selected on the basis of gene delivery efficacy and then used for the synthesis of a stratified molecular weight polymer library. By eliminating contributions of polymer chemical background, we were able to complete an in-depth assessment of gene delivery as a function of (1) polymer molecular weight, (2) relative mannose content, (3) polymer-membrane biophysical properties, (4) APC uptake specificity, and (5) serum inhibition. In summary, the flexibility and potential of the hybrid design featured in this work highlights the ability to systematically probe vector-associated properties for the development of translational gene delivery candidates.