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AIMS: Simple surface modifications can enhance coronary stent performance. Ultra-hydrophilic surface (UHS) treatment of contemporary bare metal stents (BMS) was assessed in vivo to verify whether such stents can provide long-term efficacy comparable to second-generation drug-eluting stents (DES) while promoting healing comparably to BMS. METHODS AND RESULTS: UHS-treated BMS, untreated BMS and corresponding DES were tested for three commercial platforms. A thirty-day and a 90-day porcine coronary model were used to characterise late tissue response. Three-day porcine coronary and seven-day rabbit iliac models were used for early healing assessment. In porcine coronary arteries, hydrophilic treatment reduced intimai hyperplasia relative to the BMS and corresponding DES platforms (1.5-fold to threefold reduction in 30-day angiographic and histological stenosis; p

Bone healing, biocompatibility, and safety employing the IlluminOss System (IS), comprised of an inflatable balloon filled with photopolymerizable liquid monomer, was evaluated in New Zealand white rabbits. Successful bone healing and callus remodeling over 6 months was demonstrated radiologically and histologically with IS implants in fenestrated femoral cortices. Biocompatibility was demonstrated with IS implants in brushed, flushed femoral intramedullary spaces, eliciting no adverse, local, or systemic responses and with similar biocompatibility to K-wires in contralateral femurs up to 1 year post-implant. Lastly simulated clinical failures demonstrated the safety of IS implants up to 1 year in the presence of liquid or polymerized polymer within the intramedullary space. Polymerized material displayed cortical bone and vasculature effects comparable to mechanical disruption of the endosteum. In the clinically unlikely scenario with no remediation or polymerization, a high dose monomer injection resulted in marked necrosis of cortical bone, as well as associated vasculature, endosteum, and bone marrow. Overall, when polymerized and hardened within bone intramedullary spaces, this light curable monomer system may provide a safe and effective method for fracture stabilization. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2181-2190, 2017.

The terminal collection and histological processing of medical devices is an expensive, labor-, and material-intensive endeavor, which requires adequate experience, innovation, and preparation for success. It is also an exciting endeavor that continually challenges, intellectually engages, and improves the skills and knowledge of the pathologist. Awareness of the importance of the medical device pathologist’s involvement, communication, and oversight throughout the development, implementation, and execution of a nonclinical assessment of a medical device is in the best interest of the test facility, the histopathology laboratory, the pathologist, the sponsor, and, ultimately, the patients. This article serves to present as a primer of key considerations for the approach and conduct of “nontoxicological” studies, defined as studies involving animal models of deployment or implantation of medical devices as well as surgical animal models.

Animal models remain the gold standard for the preclinical evaluation of tissue response, sealing and integrity of aortic endografts. Preclinical testing of the InCraft® device was performed to evaluate these attributes. Through the femoral arteries of eight male crossbred sheep, 22 mm diameter InCraft® Aortic Bifurcate devices were deployed in the abdominal aortas, and shortened 13 mm diameter iliac limbs were deployed in the right iliac arteries. Vessels were excised for radiographic and histopathologic assessment at six months. There were no instances of graft thrombosis, type I endoleak or endograft migration. No fractures of the stents or fixation barbs were observed. There were minimal inflammatory changes on histology, characterized by histiocytes and multinucleated giant cells located along the fabric. The InCraft® device has favorable tissue compatibility and functions well in a sheep model, maintaining patency and sealing without migration, stent fracture or abnormal histologic changes.

Bone healing, biocompatibility, and safety employing the IlluminOss System (IS), comprised of an inflatable balloon filled with photopolymerizable liquid monomer, was evaluated in New Zealand white rabbits. Successful bone healing and callus remodeling over 6 months was demonstrated radiologically and histologically with IS implants in fenestrated femoral cortices. Biocompatibility was demonstrated with IS implants in brushed, flushed femoral intramedullary spaces, eliciting no adverse, local, or systemic responses and with similar biocompatibility to K-wires in contralateral femurs up to 1 year post-implant. Lastly simulated clinical failures demonstrated the safety of IS implants up to 1 year in the presence of liquid or polymerized polymer within the intramedullary space. Polymerized material displayed cortical bone and vasculature effects comparable to mechanical disruption of the endosteum. In the clinically unlikely scenario with no remediation or polymerization, a high dose monomer injection resulted in marked necrosis of cortical bone, as well as associated vasculature, endosteum, and bone marrow. Overall, when polymerized and hardened within bone intramedullary spaces, this light curable monomer system may provide a safe and effective method for fracture stabilization. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2181-2190, 2017.

available in PMC 2016 March 23, Aims: We sought to evaluate the incidence of embolic material in porcine brains following vascular interventions using hydrophilic-coated sheaths. Methods and results: A new self-expanding stent and delivery system (SDS) was deployed through a hydrophilic-coated (Flexor® Ansel; Cook Medical, Bloomington, IN, USA) guiding sheath into the iliac and/or carotid arteries of 23 anaesthetised Yucatan mini swine. The animals were euthanised at three, 30, 90 and 180 days and their brains were removed for histological analysis. In an additional single control animal, the guiding sheath was advanced but no SDS was deployed. Advancement of the coated guiding sheath with or without the SDS was associated with frequent foreign material in the arterioles of the brain. The embolic material was amorphous, non-refractile, non-crystalline, non-birefringent and typically lightly basophilic with a slightly stippled appearance on haematoxylin and eosin (H&E) stain. Material was observed at all time points involving 54% of all study animals (i.e., test and control) and in vitro after incubation in 0.9% saline. Conclusions: The hydrophilic coating on a clinically used guiding sheath readily avulses and embolises to the brain during deployment in a porcine model. Further documentation of this effect and monitoring in clinical scenarios are warranted., National Institutes of Health (U.S.) (NIH (R01 GM 49039))

Current drug eluting stent (DES) technology is not optimized with regard to the pharmacokinetics of drug delivery. A novel, absorbable-coating sirolimus-eluting stent (AC-SES) was evaluated for its capacity to deliver drug more evenly within the intimal area rather than concentrating drug around the stent struts and for its ability to match coating erosion with drug release. The coating consisted of absorbable poly-lactide-co-glycolic acid (PLGA) and crystalline sirolimus deposited by a dry-powder electrostatic process. The AC-SES demonstrated enhanced drug stability under simulated use conditions and consistent drug delivery balanced with coating erosion in a porcine coronary implant model. The initial drug burst was eliminated and drug release was sustained after implantation. The coating was absorbed within 90 days. Following implantation into porcine coronary arteries the AC-SES coating is distributed in the surrounding intimal tissue over the course of several weeks. Computational modeling of drug delivery characteristics demonstrates how distributed coating optimizes the load of drug immediately around each stent strut and extends drug delivery between stent struts. The result was a highly efficient arterial uptake of drug with superior performance to a clinical bare metal stent (BMS). Neointimal thickness (0.17 ± 0.07 mm vs. 0.28 ± 0.11 mm) and area percent stenosis (22 ± 9% vs. 35 ± 12%) were significantly reduced (p < 0.05) by the AC-SES compared to the BMS 30 days after stent implantation in an overlap configuration in porcine coronary arteries. Inflammation was significantly reduced in the AC-SES compared to the BMS at both 30 and 90 days after implantation. Biocompatible, rapidly absorbable stent coatings enable the matching of drug release with coating erosion and provide for the controlled migration of coating material into tissue to reduce vicissitudes in drug tissue levels, optimizing efficacy and reducing potential toxicity., Micell Technologies, Inc., National Institutes of Health (U.S.) (R01 GM49039)

Perivascularly implanted matrix embedded endothelial cells (MEECs) are potent regulators of inflammation and intimal hyperplasia following vascular injuries. Endothelial cells (ECs) in collagen scaffolds adopt a reparative phenotype with significant therapeutic potential. Although the biology of MEECs is increasingly understood, tuning of scaffold properties to control cell-substrate interactions is less well-studied. It is hypothesized that modulating scaffold degradation would change EC phenotype. Scaffolds with differential degradation are prepared by cross-linking and predegradation. Vascular injury increases degradation and the presence of MEECs retards injury-mediated degradation. MEECs respond to differential scaffold properties with altered viability in vivo, suppressed smooth muscle cell (SMC) proliferation in vitro, and altered interleukin-6 and matrix metalloproteinase-9 expression. When implanted perivascularly to a murine carotid wire injury, tuned scaffolds change MEEC effects on vascular repair and inflammation. Live animal imaging enables real-time tracking of cell viability, inflammation, and scaffold degradation, affording an unprecedented understanding of interactions between cells, substrate, and tissue. MEEC-treated injuries improve endothelialization and reduce SMC hyperplasia over 14 d. These data demonstrate the potent role material design plays in tuning MEEC efficacy in vivo, with implications for the design of clinical therapies., National Institutes of Health (U.S.) (Grant R01 GM 49039)

Percutaneous intramedullary fixation may provide an ideal method for stabilization of bone fractures, while avoiding the need for large tissue dissections. Tibiae in 18 sheep were treated with an intramedullary photodynamic bone stabilization system (PBSS) that comprised a polyethylene terephthalate (Dacron) balloon filled with a monomer, cured with visible light in situ, and then harvested at 30, 90, or 180 days. In additional 40 sheep, a midshaft tibial osteotomy was performed and stabilized with external fixators or external fixators combined with the PBSS and evaluated at 8, 12, and 26 weeks. Healing and biocompatibility were evaluated by radiographic analysis, micro-computed tomography, and histopathology. In nonfractured sheep tibiae, PBSS implants conformably filled the medullary canal, while active cortical bone remodeling and apposition of new periosteal and/or endosteal bone was observed with no significant macroscopic or microscopic observations. Fractured sheep tibiae exhibited increased bone formation inside the osteotomy gap, with no significant difference when fixation was augmented by PBSS implants. Periosteal callus size gradually decreased over time and was similar in both treatment groups. No inhibition of endosteal bone remodeling or vascularization was observed with PBSS implants. Intramedullary application of a light-curable PBSS is a biocompatible, feasible method for fracture fixation.

Objective To determine the most appropriate anatomical location for diode laser probe placement to accurately photoablate the equine ciliary body using a contact, transscleral approach. Design Original research. Procedures Forty-two freshly enucleated adult equine eyes were evaluated. The horizontal, medial vertical, central vertical, and lateral vertical lengths of the cornea were measured from limbus to limbus. Needles were inserted perpendicular to the sclera at specific distances posterior to the external limbus at the 1, 2, 4, 5, 6, 7, 8, 10, 11 and 12 o’clock positions. The per cent frequency that needles penetrated internal anatomical regions (lens, lens zonules, pars plicata, anterior, middle, and posterior pars plana, ora ciliaris retinae, or retina), when inserted at 2, 4, 6, and 8 mm posterior to the limbus, were calculated for all eyes combined, for right vs. left, for males vs. females, and for three age groups. The internal distance from the limbus to the anterior pars plana, and from the anterior pars plana to the ora ciliaris retinae were also measured in six of the horses (12 eyes). Mean distances and standard deviations were computed for all parameters. Results Average corneal sizes and standard deviations were: 30.24 mm ± 1.53 (horizontal); 24.69 mm ± 1.52 (central vertical); 22.79 mm ± 1.49 (medial vertical); and 19.79 mm ± 1.55 (lateral vertical). Internal distances of the pars plicatas ranged from 5.33 mm ± 0.49 to 10.67 mm ± 1.15. Internal distances of the pars planas ranged from 0.33 mm ± 0.49 to 3.17 mm ± 0.39. High probabilities of penetrating the pars plicata correspond to positions 4 mm posterior to the external limbus dorsotemporal 10, 11 o’clock (OD), and 1, 2 o’clock (OS), dorsonasal 1 o’clock (OD) and 11 o’clock (OS), and ventrotemporal 5–7 o’clock (OU). Low probabilities of penetrating the pars plicata correspond to positions ventronasal 4 o’clock (OD), 8 o’clock (OS) and dorsonasal 2 o’clock (OD), 10 o’clock (OS) at 4 and 6 mm posterior to the external limbus as well as ventrotemporal 4 o’clock (OS), 8 o’clock (OD) at 6 mm posterior to the external limbus. Conclusions Transscleral cyclophotocoagulation may be a viable alternative to medical therapy for control of intraocular pressure in horses with glaucoma. Overall, the most accurate anatomical position on the sclera for cyclophotocoagulation of the equine eye is 4–6 mm posterior to the limbus, avoiding the nasal quadrants. Accurate transscleral cyclophotocoagulation should optimize the therapeutic outcome and minimize potential side-effects such as retinal detachment and cataract formation.

Walleye dermal sarcoma (WDS) is a common disease of walleye fish in the United States and Canada. These proliferative lesions are present autumn through winter and regress in the spring. Walleye dermal sarcoma virus (WDSV), a retrovirus distantly related to other members of the family Retroviridae , has been etiologically linked to the development of WDS. We have reported that the D-cyclin homologue [retroviral (rv) cyclin] encoded by WDSV rescues yeast conditionally deficient for cyclin synthesis from growth arrest and that WDSV-cyclin mRNA is present in developing tumors. These data strongly suggest that the rv-cyclin plays a central role in the development of WDS. To test the ability of the WDSV rv-cyclin to induce cell proliferation, we have generated transgenic mice expressing the rv-cyclin in squamous epithelia from the bovine keratin-5 promoter. The transgenic animals were smaller than littermates, had reduced numbers of hair follicles, and transgenic females did not lactate properly. Following injury the transgenic animals developed severe squamous epithelial hyperplasia and dysplasia with ultrastructural characteristics of neoplastic squamous epithelium. Immunocytochemistry studies demonstrated that the hyperplastic epithelium stained positive for cytokeratin and were abnormally differentiated. Furthermore, the rv-cyclin protein was detected in the thickened basal cell layers of the proliferating lesions. These data are the first to indicate that the highly divergent WDSV rv-cyclin is a very potent stimulator of eukaryotic cell proliferation and to demonstrate the potential of a cyclin homologue encoded by a retrovirus to induce hyperplastic skin lesions.

Clinical trials and meta-analyses demonstrate the low restenosis and stent thrombosis risks of next generation drug eluting stents (DES). Co-evolution of device, delivery technique, and drug-related factors all contribute, yet relative advantages are difficult to surmise. On a background of

Background Successful recanalization (TICI ≥ 2b) using mechanical thrombectomy (MT) with stent retriever devices is associated with good outcomes in the treatment of ischemic stroke. Preclinical TICI flow assessement is challenging due to the difficulty of consistently occluding selected blood vessels in vivo using lab-created thrombus. We describe the development of a discrete occlusive porcine clot model for predictable and repeatable assessment of TICI flow restoration and treatment effects on the vessels at the 3 day and 28 day timepoints and following MT. Methods Firm and soft thrombus were aged for 24–48 hours prior to injection into the peripheral arteries of eight Yorkshire pigs. Oversized clots were introduced to the target region through a guide catheter via a customized luer to minimize shear/fragmentation. Clots were allowed to stabilize in the vessel prior to treatment. Clot retrieval was performed with a novel Revascularization Device (Neuravi Ltd.) or Trevo® ProVue Retriever (Stryker Inc.) as a control. TICI flow was assessed following clot administration and after thrombectomy. Vascular response to the treatment was assessed histologically at 3 and 28 days. Results Complete occlusion was achieved in 92% (22/24) of the targeted arteries by insertion of one (20/22) or two (2/22) pre-measured clots. Of the occluded arteries treated, TICI 3 flow restoration was achieved in all cases (100%) with the Neuravi device and 90% cases with Trevo; single pass recanalization (TICI ≥ 2b) rates were 92% and 80% respectively. All vessels were patent at 3 and 28 days post treatment, and histologically the prototype Neuravi revascularization device was associated with favorable local and end organ tissue responses, and was comparable to the Trevo ProVue. Conclusions Novel methods were developed to provide consistent thrombus morphology enabling controlled delivery and adherence and facilitating comparative analysis of thrombectomy devices using angiographic (TICI) flow assessment in the preclinical swine model. Angiographic assessments and vessel response to treatment by Mechanical Thrombectomy were successfully completed following occlusion with firm and soft thrombus administration. Disclosures L. Bailey: 1; C; Neuravi Ltd. M. Gilvarry: 5; C; Neuravi Ltd. M. Holian: 5; C; Neuravi Ltd. A. Tzafriri: 1; C; Neuravi Ltd. J. Stanley: 1; C; Neuravi Ltd. E. Edelman: None.

Mutations in sorting nexin 10 (Snx10) have recently been found to account for roughly 4% of all human malignant osteopetrosis, some of them fatal. To study the disease pathogenesis, we investigated the expression of Snx10 and created mouse models in which Snx10 was knocked down globally or knocked out in osteoclasts. Endocytosis is severely defective in Snx10-deficent osteoclasts, as is extracellular acidification, ruffled border formation, and bone resorption. We also discovered that Snx10 is highly expressed in stomach epithelium, with mutations leading to high stomach pH and low calcium solubilization. Global Snx10-deficiency in mice results in a combined phenotype: osteopetrosis (due to osteoclast defect) and rickets (due to high stomach pH and low calcium availability, resulting in impaired bone mineralization). Osteopetrorickets, the paradoxical association of insufficient mineralization in the context of a positive total body calcium balance, is thought to occur due to the inability of the osteoclasts to maintain normal calcium–phosphorus homeostasis. However, osteoclast-specific Snx10 knockout had no effect on calcium balance, and therefore led to severe osteopetrosis without rickets. Moreover, supplementation with calcium gluconate rescued mice from the rachitic phenotype and dramatically extended life span in global Snx10-deficient mice, suggesting that this may be a life-saving component of the clinical approach to Snx10-dependent human osteopetrosis that has previously gone unrecognized. We conclude that tissue-specific effects of Snx10 mutation need to be considered in clinical approaches to this disease entity. Reliance solely on hematopoietic stem cell transplantation can leave hypocalcemia uncorrected with sometimes fatal consequences. These studies established an essential role for Snx10 in bone homeostasis and underscore the importance of gastric acidification in calcium uptake., Author Summary We found that Snx10, a molecule expressed in osteoclasts, was also expressed in the stomach. Studies in tissue specific or global knock-down mice showed that Snx10 deficiency resulted in a phenotype that was a consequence of deficiencies in both osteoclasts and gastric zymogenic cells. Our studies add to a growing list of genes, including atp6i (Tcirg1), whose expression is required both in bone and stomach to maintain normal gastric acidification and calcium absorption. This work provides additional insight into the mechanisms governing the regulation of bone accrual by the gastrointestinal tract. Because osteopetrorickets has not been described clinically in Snx10-related osteopetrosis, these findings highlight the importance of considering impaired acidification in both stomach and bone in osteopetrotic patients with mutations in SNX10 and other genes with similar patterns of expression and activities. Because defects in gastric differentiation and/or gastric acidification may cause or contribute to hypocalcemia, bone insufficiency, and early death, our results suggest that dietary calcium supplementation could be a life-saving intervention in these patients.

Peripheral vascular interventions frequently employ guiding sheaths with hydrophilic coatings raising the concern for the embolization of this material clinically as increasingly documented. A peripheral stent and delivery system (SDS) were deployed in the iliac and/or carotid arteries of 23

Human T cell leukemia/lymphoma virus type-1 (HTLV-1) is recognized as the etiological agent of adult T cell leukemia (ATL). Although HTLV-1 can immortalize human lymphocytes in culture, identification of molecular events leading to tumorigenesis after HTLV-1 infection remain elusive. SCID/bg and NOD/SCID mice have reduced natural killer (NK) cell activity and were inoculated intraperitoneally with HTLV-1 transformed cells to refine and characterize the SCID mouse as a small animal model for investigation of HTLV-1 tumorigenesis. HTLV-1 transformed cell lines originally derived by cocultivation of uninfected peripheral blood mononuclear cells (PBMC) with lethally irradiated leukemic cells from patient samples (SLB-1, MT-2 and HT-1-RV) were lymphomagenic when inoculated into NOD/SCID mice. In contrast, immortalized cell lines generated by transfection PBMC with an infectious molecular clone of HTLV-1 (ACH or ACH.p12) were not tumorigenic. The differing behaviors of HTLV-1 infected cell lines in NOD/SCID mice indicates that viral infection and immortalization of human PBMC for growth in culture is not sufficient for induction of a tumorigenic phenotype. The higher level of engraftment of HTLV-1 transformed cell lines in NOD/SCID mice suggests that this is an effective animal model to investigate molecular determinants of HTLV-1 lymphomagenesis.

Human T-lymphotropic virus type 1 (HTLV-1) is a complex retrovirus encoding regulatory and accessory genes in four open reading frames (ORF I to IV) of the pX region. We have demonstrated an important role of pX ORF I expression, which encodes p12I, in establishment of HTLV-1 infection in a rabbit model and for optimal viral infectivity in quiescent primary lymphocytes. These data indicated that p12Imay enhance lymphocyte activation and thereby promote virus infection. To further define the role of p12Iin cell activation, we characterized the subcellular localization of p12Iin transfected 293T cells and HeLa-Tat cells by multiple methods, including immunofluorescence confocal microscopy, electron microscopy, and subcellular fractionation. Herein, we demonstrate that p12Iaccumulates in the endoplasmic reticulum (ER) andcis-Golgi apparatus. The location of p12Iwas unchanged following treatments with both cycloheximide (blocking de novo protein synthesis) and brefeldin A (disrupting ER-to-Golgi protein transport), indicating that the protein is retained in the ER andcis-Golgi. Moreover, using coimmunoprecipitation assays, we identify the direct binding of p12Iwith both calreticulin and calnexin, resident ER proteins which regulate calcium storage. Our results indicate that p12Idirectly binds key regulatory proteins involved in calcium-mediated cell signaling and suggest a role of p12Iin the establishment of HTLV-1 infection by activation of host cells.