Stalboerger, Paul G.

Coronary angiography is the gold standard for the diagnosis and treatment of epicardial coronary artery disease. Further, it is an essential tool for conduction of translational cardiac research on large animal models, in the development of novel cardiac therapies. While in humans coronary angiography has an exceedingly low mortality rate; in pigs, procedural mortality has been reported as high as 15%, likely due to unsuitable variations in angiographic techniques. Porcine models are used due to the resemblance of cardiac function and anatomy to humans. However, procedural guidelines delineating proper equipment to be used for angiography in this model has yet to be systematically assessed. Aims: To evaluate clinically common catheters for their utility in the safe engagement of the coronary vessels in pigs. Establish optimal workflow and fluoroscopy views for safe coronary artery engagement and angiography. Method/Results: Percutaneous superficial femoral artery access was acquired via ultrasound guidance and subsequent cardiac catheterization was performed in sus domesticus weighing 35-50 kg. Catheters that were tested included the JL 2.5, JL3.0, JR 3.0, AR1, AL1, MPA1, Champ1, 3DRC, hockey stick and RCB (5-7 french) operated over a standard .035 J tip wire. AP views were optimum to engage both the left and right coronary vessels. Only AR1, 3DRC, and hockey stick catheters successfully engaged the RCA, while all catheters tested could successfully engage the LCA. AR1 was noted to be the best for RCA engagement and AL1 for Left system engagement. AR1 was also the most succesful in engagement of both LM and RCA in same pig. AL1 provided the most stable engagement for Left coronary system. AR1/JL were better for LAD intervensions. AL1 is best for LCX intervensions Conclusion: We present a systematic description of percutaneous coronary angiographic procedures highlighting that AL for the LCA and AR for the RCA are the best choice of catheters for fastest and safest engagement of the coronary arteries limiting both radiation time and contrast use. While variations in anatomy can mandate changes in angiographic angles and catheter techniques, AP visualization and use of AL and AR catheters provided the most consistent and effective approach for porcine angiography.

AbstractPatients with viral myocarditis are at risk of sudden death and may progress to dilated cardiomyopathy (DCM). Currently, no disease‐specific therapies exist to treat viral myocarditis. Here it is examined whether reconstituted, lyophilized extracellular vesicles (EVs) from platelets from healthy men and women reduce acute or chronic myocarditis in male mice. Human‐platelet‐derived EVs (PEV) do not cause toxicity, damage, or inflammation in naïve mice. PEV administered during the innate immune response significantly reduces myocarditis with fewer epidermal growth factor (EGF)‐like module‐containing mucin‐like hormone receptor‐like 1 (F4/80) macrophages, T cells (cluster of differentiation molecules 4 and 8, CD4 and CD8), and mast cells, and improved cardiac function. Innate immune mediators known to increase myocarditis are decreased by innate PEV treatment including Toll‐like receptor (TLR)4 and complement. PEV also significantly reduces perivascular fibrosis and remodeling including interleukin 1 beta (IL‐1β), transforming growth factor‐beta 1, matrix metalloproteinase, collagen genes, and mast cell degranulation. PEV given at days 7–9 after infection reduces myocarditis and improves cardiac function. MicroRNA (miR) sequencing reveals that PEV contains miRs that decrease viral replication, TLR4 signaling, and T‐cell activation. These data show that EVs from the platelets of healthy individuals can significantly reduce myocarditis and improve cardiac function.

Objective The aim of the study was to compare vaginal wound healing after exosome injection in a porcine mesh exposure model with (1) single versus multiple dose regimens and (2) acute versus subacute exposure. Methods Six 80-kg Yorkshire-crossed swine each had 2 polypropylene meshes implanted to create the vaginal mesh exposure model. Animals were divided into 3 groups based on number and timing of exosome injection: (1) single purified exosome product (PEP) injection (acute-single), (2) weekly PEP injections (acute-weekly, 4 total injections), and (3) delayed single injection (subacute-single). Acute and subacute injections occurred 1 and 8 weeks after mesh implantation, respectively. EdU, a thymidine analog, was given twice weekly after the first injection to track tissue regeneration. Euthanasia and tissue analysis occurred 4 weeks after the first injection. ImageJ was used to quantify epithelial thickness, cellular proliferation, and capillary density. Statistical analysis was performed using analysis of variance and post hoc Tukey test. Results Acute-single PEP injection tissues mirrored pilot study results, validating replication of protocol. Within the acute groups, weekly dosing resulted in 1.5× higher epithelial thickness (nonsignificant), 1.8× higher epithelial proliferation ( P < 0.05), and 1.5× higher regenerated capillary density ( P < 0.05) compared with single injection. Regarding chronicity of the exposure, the subacute group showed 1.7× higher epithelial proliferation (nonsignificant) and similar capillary density and epithelial thickness as compared with the acute group. Conclusions Exosome redosing resulted in significantly greater epithelial proliferation with significantly higher regenerated capillary density, leading to a trend toward thicker epithelium. Subacute exposure exhibited similar regeneration to acute exposure despite a delayed injection timeline. These results contribute to a growing body of preclinical research demonstrating utility of exosomes in pelvic floor disorders.

Objectives The purpose of this study was to explore the utility of an injectable purified exosome product derived from human apheresis blood to (1) augment surgical closure of vaginal mesh exposures, and (2) serve as a stand-alone therapy for vaginal mesh exposure. Methods Sixteen polypropylene meshes (1×1–3×3 cm) were implanted in the vaginas of 7 Yorkshire-crossed pigs by urogynecologic surgeons (day 0). On day 7, group 1 underwent surgical intervention via vaginal tissue suture reclosure with (n=2 pigs, n=4 meshes) or without (n=2 pigs, n=4 meshes) exosome injection; group 2 underwent medical intervention with an exosome injection (n=3, n=8 meshes). One animal in group 2 was given oral 2′-deoxy-5-ethynyluridine to track cellular regeneration. Euthansia occurred at 5 weeks. Results Mesh exposures treated with surgical closure alone experienced reexposure of the mesh. Exosome treatment with or without surgical closure resulted in partial to full mesh exposure resolution up to 3×3 cm. Exosome-treated tissues had significantly thicker regenerated epithelial tissue (208 μm exosomes-only and 217 μm surgery+exosomes, versus 80 μm for surgery-only; P < 0.05); evaluation of 2′-deoxy-5-ethynyluridine confirmed de novo regeneration throughout the epithelium and underlying tissues. Capillary density was significantly higher in the surgery+exosomes group ( P = 0.03). Surgery-only tissues had a higher inflammatory and fibrosis response as compared with exosome-treated tissues. Conclusions In this pilot study, exosome treatment augmented healing in the setting of vaginal mesh exposure, reducing the incidence of mesh reexposure after suture closure and decreasing the area of mesh exposure through de novo tissue regeneration after exosome injection only. Further study of varied local tissue conditions and mesh configurations is warranted.

ObjectiveWe aim to create a model of mandibular osteoradionecrosis in athymic rats. Athymic rats provide an immunosuppressed environment whereby human stem cells and biomaterials can be used to investigate regenerative solutions for osteoradionecrosis, bridging the gap between in vivo testing and clinical application.Study DesignProspective animal study.SettingAcademic otolaryngology department laboratory.Subjects and MethodsAfter Institutional Animal Care and Use Committee approval, 10 athymic nude rats were divided into 2 groups. The experimental group (n = 6) underwent irradiation (20 Gy), while the control group (n = 4) underwent sham irradiation catheter placement only. All 10 rats underwent extraction of the second mandibular molar 7 days later. The rats were sacrificed 28 days after dental extraction, and their mandibles were harvested. The mandibles were examined with histologic analysis and bone volume analysis based on 3‐dimensional micro–computed tomography.ResultsAll 10 rats survived the experiment period. Radiographic and histologic analysis revealed decreased bone formation in the experimental group compared with the control group. Jaw region volume ratio was 0.83 for the experimental group versus 0.97 in the control group (P =. 003). The region‐of‐interest volume ratio was 0.75 in the experimental group and 0.97 in the control group (P =. 005). Histologically, there were increased osteoclasts (P =. 02) and decreased osteoblasts (P =. 001) as well as increased fibrosis in the experimental group versus the control group.ConclusionMandibular osteoradionecrosis can be effectively and reproducibly produced in an athymic rat model. This will allow further research to study regenerative medicine in an athymic rat model.