Influence of recipient age on deceased donor kidney transplant outcomes in the expanded criteria donor era.

METHODS: We performed a retrospective single-center review of 884 deceased donor (DD) kidney transplants (KTs) in patients (pts) aged ≥40 yr. RESULTS: One hundred and four (11.8%) pts were ≥70 (mean 74), 286 (32.3%) were 60-69 (mean 64), and 494 (55.9%) were 40-59 (mean 51) yr of age; the proportion receiving expanded criteria donor (ECD) kidneys were 66%, 49%, and 30%, respectively (p < 0.001). Mean waiting time (15 months) was shorter for pts ≥70 yr compared to the other two groups combined (23 months, p = 0.002). With mean follow-up ranging from 54 to 70 months, actual pt (81% vs. 72%, p = 0.002) and graft (66% vs. 58.5%, p = 0.03) survival rates were higher in the younger compared to the two older groups, whereas death-censored graft survival was similar (76% vs. 73%, p = NS). The incidence of death with a functioning graft correlated with older recipient age group, increasing from 13% to 18% to 23% (p = 0.01). The incidence of delayed graft function was similar (31.8% overall), and renal function, morbidity, and resource utilization were similar among groups. CONCLUSIONS: By directing ECD kidneys to selected older pts, waiting times are reduced and censored survival outcomes are similar to middle-aged patients, suggesting that matching strategies for graft and patient lifespan are warranted.

Advances in the Formulation and Assembly of Non-Cationic Lipid Nanoparticles for the Medical Application of Gene Therapeutics.

Lipid nanoparticles have become increasingly popular delivery platforms in the field of gene therapy, but bench-to-bedside success has been limited. Many liposomal gene vectors are comprised of synthetic cationic lipids, which are associated with lipid-induced cytotoxicity and immunogenicity. Natural, non-cationic PEGylated liposomes (PLPs) demonstrate favorable biocompatibility profiles but are not considered viable gene delivery vehicles due to inefficient nucleic acid loading and reduced cellular uptake. PLPs can be modified with cell-penetrating peptides (CPPs) to enhance the intracellular delivery of liposomal cargo but encapsulate leakage upon CPP-PLP assembly is problematic. Here, we aimed to identify parameters that overcome these performance barriers by incorporating nucleic acid condensers during CPP-PLP assembly and screening variable ethanol injection parameters for optimization. CPP-PLPs were formed with R8-amphiphiles via pre-insertion, post-insertion and post-conjugation techniques and liposomes were characterized for size, surface charge, homogeneity, siRNA encapsulation efficiency and retention and cell associative properties. Herein we demonstrate that pre-insertion of stearylated R8 into PLPs is an efficient method to produce non-cationic CPP-PLPs and we provide additional assembly parameter specifications for a modified ethanol injection technique that is optimized for siRNA encapsulation/retention and enhanced cell association. This assembly technique could provide improved clinical translation of liposomal based gene therapy applications.

Liposomal Nanocarriers Designed for Sub-Endothelial Matrix Targeting under Vascular Flow Conditions.

Vascular interventions result in the disruption of the tunica intima and the exposure of sub-endothelial matrix proteins. Nanoparticles designed to bind to these exposed matrices could provide targeted drug delivery systems aimed at inhibiting dysfunctional vascular remodeling and improving intervention outcomes. Here, we present the progress in the development of targeted liposomal nanocarriers designed for preferential collagen IV binding under simulated static vascular flow conditions. PEGylated liposomes (PLPs), previously established as effective delivery systems in vascular cells types, served as non-targeting controls. Collagen-targeting liposomes (CT-PLPs) were formed by conjugating established collagen-binding peptides to modified lipid heads via click chemistry (CTL), and inserting them at varying mol% either at the time of PLP assembly or via micellar transfer. All groups included fluorescently labeled lipid species for imaging and quantification. Liposomes were exposed to collagen IV matrices statically or via hemodynamic flow, and binding was measured via fluorometric analyses. CT-PLPs formed with 5 mol% CTL at the time of assembly demonstrated the highest binding affinity to collagen IV under static conditions, while maintaining a nanoparticle characterization profile of ~50 nm size and a homogeneity polydispersity index (PDI) of ~0.2 favorable for clinical translation. When liposomes were exposed to collagen matrices within a pressurized flow system, empirically defined CT-PLPs demonstrated significant binding at shear stresses mimetic of physiological through pathological conditions in both the venous and arterial architectures. Furthermore, when human saphenous vein explants were perfused with liposomes within a closed bioreactor system, CT-PLPs demonstrated significant ex vivo binding to diseased vascular tissue. Ongoing studies aim to further develop CT-PLPs for controlled targeting in a rodent model of vascular injury. The CT-PLP nanocarriers established here show promise as the framework for a spatially controlled delivery platform for future application in targeted vascular therapeutics.

Dietary supplementation with Zyflamend poly-herbal extracts and fish oil inhibits intimal hyperplasia development following vascular intervention.

The polyherbal blend Zyflamend™ has been shown to have anti-inflammatory properties and attenuate inflammatory-modulated pathologies. Fish oils have also been shown to have cardioprotective properties. However, the beneficial effects of their combination have not been investigated. Intimal hyperplasia (IH), a pathological remodeling response of a vessel to injury, is heavily regulated by an immune-mediated reaction. The objective of this study was to determine if dietary supplementation with Zyflamend and/or Wholemega could affect inflammatory-dependent vascular remodeling mechanisms when provided at human equivalent doses. Based on their anti-inflammatory properties and protective benefits demonstrated in previous pre-clinical studies, we hypothesized administration of these supplements would prevent IH in an animal model of vascular injury. The diets of aged male rats were supplemented with human equivalent doses of Zyflamend (Zyf) and/or Wholemega (WMega) or placebo (Plac) for 1wk prior to balloon angioplasty (BA)-induced injury of the left carotid artery. At 28d post-injury morphometric analysis of carotid tissue revealed IH was decreased in Zyf + WMega animals compared to placebo, while Zyf or WMega independently had no significant effect. Serum cytokine screening indicated injury-induced interleukin family isoforms, interferon-γ, and macrophage inflammatory proteins were downregulated by Zyf + WMega. Immunohistochemical staining for monocyte/macrophage phenotypic markers revealed that while overall monocyte/macrophage vessel infiltration was not affected, Zyf + WMega limited the alternative differentiation of M2 macrophages and reduced the presence of myofibroblasts in the injured vessel wall. In summary, dietary supplementation with Zyf + WMega attenuated the acute inflammatory response following vascular injury and inhibited IH development in vivo.