In vitro assessments of nanoplexes of polyethylenimine-coated graphene oxide-plasmid through various cancer cell lines and primary mesenchymal stem cells

by Parichehr Maleki, Ali Dinari, Babak Jahangiri, Jamshid Raheb

Efficient gene therapy relies on an efficient gene delivery system. Viral gene delivery approaches excel in transferring and expressing external genes; however, their immunogenicity and difficulty in large-scale production limit their clinical applications. In contrast, nanoparticle-based gene delivery systems have gained increasing attention due to less immunogenicity and more convenience for large-scale production. Nevertheless, their poor transfection efficiency compared to viral systems remains a significant obstacle. In the present study, we investigated the transfection efficiency of our PEI-coated graphene oxides in HEK293T, Calu-3, Calu-6 cell lines, and primary human bone marrow mesenchymal stem cell (MSC). The high surface ratio and good biocompatibility of graphene oxide make it an appealing tool for gene delivery systems. However, the low dispersity of graphene oxide in aqueous environments is the first barrier that needs to be conquered. For this, we enhanced the dispersity and stability of graphene oxide in water by sonicating it for at least 5 hours at a pH of 7. Then, graphene oxide was conjugated with branched PEI (25 kDa) to have a positive charge, enabling it to condense nucleic acids with a naturally negative potential. The physio-chemical characteristics of our synthesized nano-carriers (GO-PEI) were determined by DLS, FT-IR, and AFM. The utilized plasmid in polyplexes contained a GFP gene, allowing us to verify transfection efficiency through fluorescent microscopy and flow cytometry. While GO-PEI carriers were highly efficient in transfecting HEK293T cells, the transfection efficiency in MSCs and Calu-3 cells was notably low. We suppose that the main reason for the low transfection efficiency of GO-PEI in these cells is due to its higher toxicity. Despite this, considering the various advantages of graphene oxide in drug delivery as well as its optical and electrical applications in biomedicine, we propose to functionalize graphene oxide with more biocompatible materials to enhance its potential as a successful gene carrier in these cell types.

Stratification of risk for emergent intracranial abnormalities in children with headaches: a Pediatric Emergency Care Applied Research Network (PECARN) study protocol

Introduction

Headache is a common chief complaint of children presenting to emergency departments (EDs). Approximately 0.5%–1% will have emergent intracranial abnormalities (EIAs) such as brain tumours or strokes. However, more than one-third undergo emergent neuroimaging in the ED, resulting in a large number of children unnecessarily exposed to radiation. The overuse of neuroimaging in children with headaches in the ED is driven by clinician concern for life-threatening EIAs and lack of clarity regarding which clinical characteristics accurately identify children with EIAs. The study objective is to derive and internally validate a stratification model that accurately identifies the risk of EIA in children with headaches based on clinically sensible and reliable variables.

Methods and analysis

Prospective cohort study of 28 000 children with headaches presenting to any of 18 EDs in the Pediatric Emergency Care Applied Research Network (PECARN). We include children aged 2–17 years with a chief complaint of headache. We exclude children with a clear non-intracranial alternative diagnosis, fever, neuroimaging within previous year, neurological or developmental condition such that patient history or physical examination may be unreliable, Glasgow Coma Scale score

Ethics and dissemination

Ethics approval was obtained for all participating sites from the University of Utah single Institutional Review Board. A waiver of informed consent was granted for collection of ED data. Verbal consent is obtained for follow-up contact. Results will be disseminated through international conferences, peer-reviewed publications, and open-access materials.