Non-Viral Gene Delivery to Hepatocellular Carcinoma via Intra-Arterial Injection.

Purpose: Hepatocellular carcinoma (HCC) has limited treatment options, and modest survival after systemic chemotherapy or procedures such as transarterial chemoembolization (TACE). There is therefore a need to develop targeted therapies to address HCC. Gene therapies hold immense promise in treating a variety of diseases, including HCC, though delivery remains a critical hurdle. This study investigated a new approach of local delivery of polymeric nanoparticles (NPs) via intra-arterial injection for targeted local gene delivery to HCC tumors in an orthotopic rat liver tumor model. Methods: Poly(beta-amino ester) (PBAE) nanoparticles were formulated and assessed for GFP transfection in N1-S1 rat HCC cells in vitro. Optimized PBAE NPs were next administered to rats via intra-arterial injection with and without orthotopic HCC tumors, and both biodistribution and transfection were assessed. Results: In vitro transfection of PBAE NPs led to >50% transfected cells in adherent and suspension culture at a variety of doses and weight ratios. Administration of NPs via intra-arterial or intravenous injection demonstrated no transfection of healthy liver, while intra-arterial NP injection led to transfection of tumors in an orthotopic rat HCC model. Conclusion: Hepatic artery injection is a promising delivery approach for PBAE NPs and demonstrates increased targeted transfection of HCC tumors compared to intravenous administration, and offers a potential alternative to standard chemotherapies and TACE. This work demonstrates proof of concept for administration of polymeric PBAE nanoparticles via intra-arterial injection for gene delivery in rats.

Acute Visual Disturbances and Ataxia Secondary to Attempted COVID-19 Prophylaxis With Ivermectin in a Nine-Year-Old.

Ivermectin is an antiparasitic agent listed as an essential medication by the World Health Organization. Ivermectin utilization has increased due to the popular, though inaccurate, perception of its use in COVID-19 management. Poison Control Central calls regarding ivermectin toxicity have increased 245% since pre-pandemic baselines. This case study illustrates the clinical presentation of ivermectin toxicity in a nine-year-old child with acute vision changes and ataxia. The child was given 60 mg (1 mg/kg) of veterinary-grade ivermectin by a parent, 10 times the clinically recommended dose of 0.1 mg/kg, as prophylaxis after household exposure to COVID-19. Ten hours later, the child developed new-onset blurry vision, a perception of red dots in the peripheral vision, dizziness, and balance issues. Physical examination was notable for pulsating pupils, ataxia, and dysmetria. Symptoms resolved completely after 10 hours. Ivermectin ingestion is an important diagnostic consideration in children presenting with similar symptoms. We hope our case aids in the identification of ivermectin toxicity and hastens necessary supportive measures.

Script Concordance Tests for Formative Clinical Reasoning and Problem-Solving Assessment in General Pediatrics.

Introduction: Script Concordance Tests (SCTs) are short clinical vignettes with proposed diagnoses, diagnostic studies, treatments, and management options for patient care scenarios. The SCTs included in this resource were incorporated into a required pediatric clerkship to facilitate formative student feedback and additional opportunities for precepting faculty to provide midclerkship feedback. Pediatric cases were specifically selected due to the scarcity of medical student experience with common pediatric clinical presentations. Methods: We developed eight themed SCTs comprising 72 individual test items focused on common topics in general pediatrics. Items were administered to a convenience sample of third-year medical students during their required pediatric clerkship between fall 2016 and spring 2020. To evaluate the SCTs, we conducted item analyses, as well as comparing student performance to summative assessments. Results: The mean aggregate percentage score across all SCTs was .84 (SD = .08). Student SCT performance was related to USMLE Step 2 Clinical Knowledge scores, clerkship grades, and NBME Pediatrics Shelf Exam scores. Discussion: These SCTs facilitated feedback to medical students in the clinical learning environment. Their current form provides a means of exploring student clinical reasoning and problem-solving and can be used at a single point or to measure longitudinally. When paired with structured subject- and competency-specific midclerkship student evaluation, SCTs helped facilitate timely feedback to students via immediate explanations of each question. SCTs can assist students in recognizing and reflecting on potential knowledge gaps.

Polymeric nanoparticles for dual-targeted theranostic gene delivery to hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) develops predominantly in the inflammatory environment of a cirrhotic liver caused by hepatitis, toxin exposure, or chronic liver disease. A targeted therapeutic approach is required to enable cancer killing without causing toxicity and liver failure. Poly(beta-amino-ester) (PBAE) nanoparticles (NPs) were used to deliver a completely CpG-free plasmid harboring mutant herpes simplex virus type 1 sr39 thymidine kinase (sr39) DNA to human HCC cells. Transfection with sr39 enables cancer cell killing with the prodrug ganciclovir and accumulation of 9-(4-18F-fluoro-3-hydroxymethylbutyl)guanine (18F-FHBG) for in vivo imaging. Targeting was achieved using a CpG-free human alpha fetoprotein (AFP) promoter (CpGf-AFP-sr39). Expression was restricted to AFP-producing HCC cells, enabling selective transfection of orthotopic HCC xenografts. CpGf-AFP-sr39 NP treatment resulted in 62% reduced tumor size, and therapeutic gene expression was detectable by positron emission tomography (PET). This systemic nanomedicine achieved tumor-specific delivery, therapy, and imaging, representing a promising platform for targeted treatment of HCC.

Poly(beta-amino ester) nanoparticles enable tumor-specific TRAIL secretion and a bystander effect to treat liver cancer.

Despite initial promise, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-based approaches to cancer treatment have yet to yield a clinically approved therapy, due to delivery challenges, a lack of potency, and drug resistance. To address these challenges, we have developed poly(beta-amino ester) (PBAE) nanoparticles (NPs), as well as an engineered cDNA sequence encoding a secretable TRAIL (sTRAIL) protein, to enable reprogramming of liver cancer cells to locally secrete TRAIL protein. We show that sTRAIL initiates apoptosis in transfected cells and has a bystander effect to non-transfected cells. To address TRAIL resistance, NP treatment is combined with histone deacetylase inhibitors, resulting in >80% TRAIL-mediated cell death in target cancer cells and significantly slowed xenograft tumor growth. This anti-cancer effect is specific to liver cancer cells, with up to 40-fold higher cell death in HepG2 cancer cells over human hepatocytes. By combining cancer-specific TRAIL NPs with small-molecule-sensitizing drugs, this strategy addresses multiple challenges associated with TRAIL therapy and offers a new potential approach for cancer treatment.