Search

Lipoprotein mimetic nanostructures, which consist of an amphiphilic lipid shell, a hydrophobic core, and an apolipoprotein mimetic peptide, serve as a versatile platform for the design of drug delivery vehicles as well as the investigation of supramolecular assemblies. Porphyrin incorporation into biomimetic lipoproteins allows one to take advantage of the inherent multimodal photophysical properties of porphyrins, yielding various fluorescence, photoacoustic, and photodynamic agents. To facilitate their incorporation into a lipoprotein structure, porphyrins have been conjugated through a variety of strategies. However, the effects of the conjugate structure on the associated nanoparticle's phototherapeutic properties warrants further investigation. Herein, we systematically investigated the effects of two widely utilized porphyrin conjugates, oleylamide and lipid, on biophotonic properties of their resultant porphyrin-lipoprotein nanoparticles in vitro and in vivo. Specifically, we demonstrated that incorporation of the porphyrin moiety as an oleylamide conjugate leads to a highly stable J-aggregate with strong photoacoustic contrast, while incorporation as an ampiphilic lipid moiety into the lipid shell yields an effective fluorescent and photodynamic agent. The current study proposes a rational design strategy for next-generation lipoprotein-based phototheranostic agents, for which nanoassembly-driven biophotonic and therapeutic properties can be tailored through the specific selection of porphyrin conjugate structures.

Background: Accumulation of systemically administered nanoparticles (NPs) in lymph nodes has been exploited clinically for diagnostic imaging (e.g., USPIOs for lymph node metastasis) and therapeutic applications (e.g., vaccine delivery). However, the combination of diagnostic and therapeutic functionalities into a single theranostic NP has obliged undesirable trade-offs between either the imaging or drug delivery of the NP and their specific accumulation in lymph nodes. To overcome these trade-offs, we conducted a screen of various lipid-based theranostic NPs focusing on differing NP design and their resulting pharmacokinetic behaviours in healthy and diseased lymph node models. Methods: Lipid-based theranostic NPs with varying physicochemical characteristics (e.g., formulation, size and morphology, surface targeting, etc.) were prepared with positron emitting Cu-64 and administered systemically at equivalent NP doses in healthy and diseased rodent models (i.e., mice and rats). NP types were assessed for time-dependent accumulation in major lymph node basins via non-invasive whole-body PET/MR imaging at two or more timepoints per animal. 72-hours post-injection the animals were sacrificed, and lymph nodes and major organs were excised for gamma counting and pathological evaluation. Pharmacokinetic behaviour of NPs in healthy versus diseased lymph nodes were calculated in individual animals and in naïvely pooled datasets using non-compartmental analysis. Results: Preliminary analysis identified a leading NP candidate with specific lymph node targeting in healthy and diseased rodents: a discoidal, 35-nm peptide-targeted HDL-mimetic. In comparison with a spherical, 100-nm PEGylated NP, the discoidal NP obtained greater absolute (%ID) and relative (%ID/g) amounts of injected dose in anatomically matched lymph nodes than the spherical NP, regardless of lymph node pathology. At greatest measured concentration in healthy lymph nodes, typically 24-hpi, the differences between the discoidal and spherical NPs were on average 3-fold greater (2.893 vs. 0.864, %ID/g). Differences in other pharmacokinetic parameters such as AUC (%ID/g*h) and MRT (h) were equally pronounced. Conclusions: Our preliminary analysis uncovered a discoidal, peptide-targeted HDL-mimetic with remarkable accumulation in lymph nodes of healthy and diseased models. Future investigations will focus on the biochemical and cellular mechanisms underlying their unique lymphatic pharmacokinetics. These preliminary results provide key insights for design of theranostic NPs for non-invasive imaging and staging lymph node pathologies, and for applications in delivery of therapeutics to lymph nodes following systemic administration. Citation Format: Michael S. Valic, Mark Zheng, Lili Ding, Michelle Lai, Chris J. Zhang, Tina Ye, Jenny Ma, Michael Halim, Pamela Schimmer, Wenlei Jiang, Juan Chen, Gang Zheng. Lymph node accumulation of theranostic lipid-based nanoparticles in healthy and diseased models: Preliminary results comparing nanoparticle morphology and targeting [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 307.

Foreign bodies in the heart are rare occurrences with a limited evidence base to guide recommendations on management. We report a case of multiple cardioembolic strokes as a result of a self-inflicted sewing needle puncture from the anterior chest through the right ventricle and interventricular septum with its tip in the left ventricle close to the subvalvular apparatus in a 39-year-old psychiatric patient. We discuss issues surrounding decision making and ongoing care and highlight the importance of further follow-up and reporting of cases to form a robust evidence base to guide future recommendations.

Summary Saffold virus (SAFV) is an emerging human cardiovirus that has been shown to be ubiquitous. Initial studies of SAFV focused on respiratory and gastrointestinal infection; however, it has also recently been associated with diverse clinical symptoms including the endocrine, cardiovascular, and neurological systems. Given the systemic nature of SAFV, and its high prevalence, understanding its pathogenicity and clinical impact is of utmost importance. This comprehensive review highlights and discusses recent developments in epidemiology, human pathogenicity, animal, and molecular studies related to SAFV. It also provides detailed insights into the neuropathogenicity of SAFV. We argue that human studies have been confounded by coinfections and therefore require support from robust molecular and animal research. Thereby, we aim to provide foresight into further research to better understand this emerging virus.

Saffold virus (SAFV) is an emerging human cardiovirus that has been shown to be ubiquitous. Initial studies of SAFV focused on respiratory and gastrointestinal infection; however, it has also recently been associated with diverse clinical symptoms including the endocrine, cardiovascular, and neurological systems. Given the systemic nature of SAFV, and its high prevalence, understanding its pathogenicity and clinical impact is of utmost importance. This comprehensive review highlights and discusses recent developments in epidemiology, human pathogenicity, animal, and molecular studies related to SAFV. It also provides detailed insights into the neuropathogenicity of SAFV. We argue that human studies have been confounded by coinfections and therefore require support from robust molecular and animal research. Thereby, we aim to provide foresight into further research to better understand this emerging virus.