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Supplementary Figures S1-S2; Supplementary Table S1.

Background: Small hyperbranched polyglycerol (HPG) has been recently of interest for peritoneal dialysis, but its pharmacokinetics is barely understood. This study investigated the absorption, distribution and excretion of 1 and 3 kDa HPG. Methods: Rats (naive, 5/6 nephrectomy (5/6 Nx) or bilateral nephrectomy (BNx)) received a single dose of 3H-labelled HPG-containing solutions intraperitoneally (IP) or intravenously (IV). Radioactivity in tissues, urine and faeces was counted using a scintillation counter. Pharmacokinetic parameters were calculated using WinNonlin software. Results: During 8-h dwell with IP injected therapeutic dose of HPG-based hypertonic solutions, the plasma levels of 1 kDa HPG reached the peak at 2 h, followed by a decrease to the end, whereas 3 kDa HPG increased for the duration of the 8 h. At the experimental endpoint, the distribution of both sizes of HPG in major organs was minimal, whereas most of 1 kDa HPG was excreted via urine, and of 3 kDa remained in peritoneal cavity. The elimination of both 1 and 3 kDa HPG after either IP or IV administration was significantly delayed by 5/6 Nx or BNx as compared to naive controls. Further, 24-h faecal excretion of HPG (3 kDa) was Conclusion: Data suggest size-dependent peritoneal absorption of osmotic HPG that are not specifically absorbed by any of the organs tested. The clearance of small HPG mainly depends on kidney excretion, implying the risk of HPG accumulation in patients with end-stage kidney disease who receive maintenance dialysis with HPG.

Background: Pancreatic islet remodelling in type 1 diabetes increases somatostatin (SST) expression, which inhibits glucagon counterregulation to hypoglycemia. Here, we characterized islet morphology and hormone composition in a rodent model of insulin-deficient type 2 diabetes (T2D) . Methods: Hypoinsulinemic T2D was induced in 8-9-week-old, male, Sprague-Dawley rats (n=4) via 3 weeks of high-fat feeding and a low-dose injection of streptozotocin (STZ; 35 mg/kg) . After 2 weeks of basal insulin treatment, pancreas tissue was extracted from T2D and healthy control (n=5) rats for immunohistochemical staining of representative islets. Results: Fasted plasma C-peptide levels of hyperglycemic (24.8±3.3 mmol/l) T2D rats were reduced by ∼44% (624±64 vs. 1107±121 pmol/l; p Conclusions: Fractional area expression of glucagon and SST increased per islet in insulin-treated rats with advanced T2D. These findings may help account for the increase in SST signaling that underscores defective glucagon counterregulation to hypoglycemia in insulin-deficient diabetic states. Disclosure E. G. Hoffman: None. S. C. Atherley: None. N. Akbarian: None. N. Dsouza: None. R. Liggins: Employee; Zucara Therapeutics, Stock/Shareholder; Zucara Therapeutics. M. Riddell: Advisory Panel; Zealand Pharma A/S, Zucara Therapeutics, Consultant; Eli Lilly and Company, Jaeb Center for Health Research, Speaker’s Bureau; Dexcom, Inc., Eli Lilly and Company, Novo Nordisk. Funding GlycoNet

Recent antecedent hypoglycemia is a known source of defective glucose counter-regulation in diabetes; the mechanisms perpetuating the cycle of progressive α-cell failure and recurrent hypoglycemia remain unknown. Somatostatin has been shown to suppress the glucagon response to acute hypoglycemia in rodent models of type 1 diabetes. We hypothesized that somatostatin receptor 2 antagonism (SSTR2a) would restore glucagon counterregulation and delay the onset of insulin-induced hypoglycemia in recurrently hypoglycemic, nondiabetic male rats. Healthy, male, Sprague–Dawley rats (n = 39) received bolus injections of insulin (10 U/kg, 8 U/kg, 5 U/kg) on 3 consecutive days to induce hypoglycemia. On day 4, animals were then treated with SSTR2a (10 mg/kg; n = 17) or vehicle (n = 12) 1 hour prior to the induction of hypoglycemia using insulin (5 U/kg). Plasma glucagon level during hypoglycemia was ~30% lower on day 3 (150 ± 75 pg/mL; P < .01), and 68% lower on day 4 in the vehicle group (70 ± 52 pg/mL; P < .001) compared with day 1 (219 ± 99 pg/mL). On day 4, SSTR2a prolonged euglycemia by 25 ± 5 minutes (P < .05) and restored the plasma glucagon response to hypoglycemia. Hepatic glycogen content of SSTR2a-treated rats was 35% lower than vehicle controls after hypoglycemia induction on day 4 (vehicle: 20 ± 7.0 vs SSTR2a: 13 ± 4.4 µmol/g; P < .01). SSTR2a treatment reverses the cumulative glucagon deficit resulting from 3 days of antecedent hypoglycemia in healthy rats. This reversal is associated with decreased hepatic glycogen content and delayed time to hypoglycemic onset. We conclude that recurrent hypoglycemia produces glucagon counterregulatory deficiency in healthy male rats, which can be improved by SSTR2a.

Background: SSTR2a rescues glucagon counterregulation in type 1 diabetic rats. Here, we investigated its potential for resisting hypoglycemic onset in insulin-treated rats with T2D. Methods: T2D was induced in 8-9-week-old, male, Sprague-Dawley rats (n=20) via 3-weeks of high-fat feeding and low-dose streptozotocin (35 mg/kg). After 1 week of basal insulin maintenance, N=10 healthy and N=20 T2D rats were treated with SSTR2a (3 mg/kg ZT-01, SC) or vehicle in a crossover design (1 wk apart), 60 min prior to hypoglycemic induction via insulin aspart bolus (6 U/kg). Results: SSTR2a increased plasma glucagon levels for up to 120 min after insulin challenge, with a 2.2-fold increase in glucagon AUC (32167 ± 6658 vs. 14428 ± 3673 pg*min/mL; p Conclusions: SSTR2a increased glucagon secretion following insulin overdose and delayed the onset of hypoglycemia in T2D rats. SSTR2a may be a promising therapeutic tool for alleviating hypoglycemic risk in intensively-treated T2D. Disclosure E. G. Hoffman: None. N. Dsouza: None. J. Aiken: None. R. Liggins: Employee; Self; Zucara Therapeutics Inc. M. Riddell: Advisory Panel; Self; Zealand Pharma A/S, Consultant; Self; Lilly Diabetes, Research Support; Self; Dexcom, Inc., Insulet Corporation, Speaker’s Bureau; Self; Novo Nordisk Inc., Sanofi, Stock/Shareholder; Self; Zucara Therapeutics Inc. Funding GlycoNet

Background: Defective glucagon counterregulation to hypoglycemia in T1D involves elevated somatostatin signalling on the α cell. In rats, SSTR2a treatment (ZT-01 Methods: High fat fed, low dose streptozotocin (T2D) and healthy rats were treated with subcutaneous ZT-01 or vehicle (N=7-8/group). Glycemia, glucagon and C-peptide were measured for 4 h post-dose. Results: SSTR2a treatment promoted a significant rise in basal glucagon in both T2D and control rats, up to 3 hours post-dose. Basal C-peptide was lower in T2D versus healthy rats (1.9 vs. 2.5 ng/ml) increasing in both groups 30 min after SSTR2a dosing (2.7 vs. 4.1 ng/mL). Both diabetes (p=0.03) and treatment (p=0.01) were significant effects (2-way ANOVA). Post-dose glucose was elevated from baseline in T2D but not in healthy rats. Conclusion: High dose SSTR2a transiently increased glucagon. C-peptide was increased to a lesser extent in T2D. Consequently, glucose levels were affected in T2D but not healthy rats. Insulin production and sensitivity in T2D may play an important role in responses to SSTR2a in this model. Disclosure N. C. D9souza: None. E. G. Hoffman: None. S. C. Atherley: None. S. Champsi: None. M. Popkov: None. R. Liggins: Employee; Self; Zucara Therapeutics Inc. M. Riddell: Advisory Panel; Self; Zealand Pharma A/S, Consultant; Self; Lilly Diabetes, Research Support; Self; Dexcom, Inc., Insulet Corporation, Speaker9s Bureau; Self; Novo Nordisk Inc., Sanofi, Stock/Shareholder; Self; Zucara Therapeutics Inc. Funding GlycoNet

Background Endogenous fibrinolytic activation contributes to coagulopathy and mortality after trauma. Administering tranexamic acid (TXA), an antifibrinolytic agent, is one strategy to reduce bleeding; however, it must be given soon after injury to be effective and minimize adverse effects. Administering TXA topically to a wound site would decrease the time to treatment and could enable both local and systemic delivery if a suitable formulation existed to deliver the drug deep into wounds adequately. Objectives To determine whether self-propelling particles could increase the efficacy of TXA. Methods Using previously developed self-propelling particles, which consist of calcium carbonate and generate CO2 gas, TXA was formulated to disperse in blood and wounds. The antifibrinolytic properties were assessed in vitro and in a murine tail bleeding assay. Self-propelled TXA was also tested in a swine model of junctional hemorrhage consisting of femoral arteriotomy without compression. Results Self-propelled TXA was more effective than non-propelled formulations in stabilizing clots from lysis in vitro and reducing blood loss in mice. It was well tolerated when administered subcutaneously in mice up to 300 to 1000 mg/kg. When it was incorporated in gauze, four of six pigs treated after a femoral arteriotomy and without compression survived, and systemic concentrations of TXA reached approximately 6 mg/L within the first hour. Conclusions A formulation of TXA that disperses the drug in blood and wounds was effective in several models. It may have several advantages, including supporting local clot stabilization, reducing blood loss from wounds, and providing systemic delivery of TXA. This approach could both improve and simplify prehospital trauma care for penetrating injury.

Iatrogenic hypoglycemia remains one of the most serious risks for people with type 1 diabetes (T1D) undergoing intensive insulin therapy. Development of counterregulatory failure, occurring in the early stages of diabetes, highlighted by loss of the ability to secrete glucagon in response to hypoglycemia, is one of the main contributing factors. While the reason for this loss is still uncertain, it has been suggested that enhanced secretion of the pancreatic hormone, somatostatin, in T1D may play a role. Previously, it was reported that antagonism of somatostatin receptor 2 (SSTR2) with the peptide PRL-2903 successfully improved the glucagon response to insulin-induced hypoglycemia in streptozotocin (STZ)-diabetic rats. In the current study, we assessed the effectiveness of a new SSTR2 antagonist, ZT-01, to prevent hypoglycemia during an insulin bolus challenge and evaluated the effect of both ZT-01 and PRL-2903 under stepped hyperinsulinemic-euglycemic-hypoglycemic clamp conditions. In both studies, STZ-diabetic rats maintained with daily insulin were administered either vehicle, PRL-2903 (10 mg/kg) or ZT-01 (10 mg/kg) intraperitoneally, one hour prior to the induction of hypoglycemia. ZT-01 was more effective than PRL-2903 in preventing the onset of hypoglycemia in response to the insulin bolus challenge. Median time of hypoglycemia onset (BG ≤54 mg/dL) was 60 min in controls, 70 min with PRL-2903 administration, and 125 min with ZT-01 administration. Furthermore, all control and PRL-2903 dosed rats experienced, while 28% of rats receiving ZT-01, avoided hypoglycemia. During the hypoglycemic clamp, ZT-01 was more effective than PRL-2903 at improving glucagon responses in hypoglycemia. ZT-01 administration increased glucagon peak by 4-fold over the response to PRL-2903 (P Disclosure J. Aiken: None. N.C. D’Souza: None. E. Simonson: None. R. Farhat: None. O. Chan: None. R. Liggins: Advisory Panel; Self; Zucara Therapeutics Inc. Stock/Shareholder; Self; Zucara Therapeutics Inc. M. Riddell: Advisory Panel; Self; Zucara Therapeutics Inc. Consultant; Self; Lilly Diabetes. Research Support; Self; Dexcom, Inc., Insulet Corporation. Speaker’s Bureau; Self; Medtronic, Novo Nordisk A/S. Funding JDRF; The Leona M. and Harry B. Helmsley Charitable Trust

Restoration of the lost glucagon response to hypoglycemia may be an effective means to prevent the onset of hypoglycemia in patients with type 1 diabetes (T1D). Elevation of the inhibitory hormone somatostatin in T1D may act on alpha cells, via the somatostatin receptor 2 (SSTR2), to suppress glucagon release during hypoglycemia. We previously demonstrated that a novel SSTR2 antagonist, ZT-01, exhibited superior efficacy at restoring the glucagon response to hypoglycemia compared to an established SSTR2 antagonist, PRL-2903, when given intraperitoneally at a dose of 10 mg/kg. In this study, we first evaluated the pharmacokinetics of ZT-01 in healthy Sprague-Dawley rats. Within one hour after intraperitoneal administration of a 10 mg/kg dose, ZT-01 achieved 10-fold higher plasma Cmax compared to PRL-2903; however, pancreas concentration at 6 h post-dose was almost 4-fold higher for PRL-2903 compared to ZT-01 and plasma concentrations were similar for both 24 h post-dose. We subsequently conducted a dose de-escalation study to identify the lowest dose of ZT-01 that could improve glucagon secretion in poorly controlled insulin-treated streptozotocin (STZ)-diabetic Sprague Dawley rats, under hypoglycemic clamp conditions. ZT-01 was administered subcutaneously one hour prior to the induction of hypoglycemia (blood glucose Disclosure R. Farhat: None. E. Simonson: None. M. Riddell: Advisory Panel; Self; Zucara Therapeutics Inc. Consultant; Self; Lilly Diabetes. Research Support; Self; Dexcom, Inc., Insulet Corporation. Speaker’s Bureau; Self; Medtronic, Novo Nordisk A/S. R. Liggins: Advisory Panel; Self; Zucara Therapeutics Inc. Stock/Shareholder; Self; Zucara Therapeutics Inc. O. Chan: None. Funding JDRF; The Leona M. and Harry B. Helmsley Charitable Trust

Objective To investigate the effect of three anticancer drugs (mitomycin c (MMC), doxorubicin or gemcitabine) on bladder wall morphology and the uptake of paclitaxel or docetaxel following coadministration. The primary objective of this study was to measure the uptake of MMC, doxorubicin or gemcitabine with or without exposure of the tissue to amine terminated cationic nanoparticles (CNPs) and to investigate any possible exfoliation effects of the three drugs on intact bladder tissue. The secondary objective was to investigate the uptake of taxane drugs (docetaxel, DTX) and paclitaxel, (PTX) from surfactant micelle formulations in the presence of MMC, doxorubicin or gemcitabine. Materials and methods Sections of fresh pig bladder tissue were incubated in Franz diffusion cells with the urothelial side exposed to solutions of doxorubicin, MMC and gemcitabine containing radioactive drug for 90 min. Some tissue samples were simultaneously exposed to each of the three drugs in combination with the surfactant micelle formulations of PTX (Taxol) or DTX (Taxotere). Tissue sections were then cryostat sectioned for drug quantitation by liquid scintillation counting or fixed for scanning electron microscopy and haematoxylin and eosin staining. Results All three drugs caused exfoliation of the urothelial layer of bladder tissues. Drug uptake studies showed that all three drugs effectively penetrated the lamina propria through to the muscular layer over a 2-h incubation and these levels were unaffected by pre-treatment with CNPs. The uptake levels of the taxane drugs PTX and DTX were significantly enhanced following simultaneous treatment of bladders with MMC, doxorubicin or gemcitabine. Conclusion The exfoliation effects of MMC, doxorubicin and gemcitabine allow for good tissue penetration of these drugs with no additional effect from CNP treatment of bladders. The observed exfoliation effect of these amine-containing drugs probably arises from a cationic interaction with the mucus and urothelium cell layer in a manner similar to that previously reported for CNPs. These studies suggest that the lack of long-term clinical efficacy of these drugs may not arise from poor intravesical drug penetration but may result from a rapid diffusion of the drugs into the deeper vascularised muscular region with rapid drug clearance. The enhanced uptake of PTX or DTX following co-administration with MMC, doxorubicin or gemcitabine probably arises from the removal of the urothelial barrier by exfoliation allowing for improved taxane partitioning into superficial layers. These effects may allow for dual drug intravesical strategies offering greatly improved taxane uptake and potential additive drug effects for improved efficacy.

Metabolic syndrome (MetS) is commonly observed among peritoneal dialysis (PD) patients, and hyperbranched polyglycerol (HPG) is a promising glucose-sparing osmotic agent for PD. However, the biocompatibility of a HPG-based PD solution (HPG) in subjects with MetS has not been investigated. This study compared the local and systemic effects of a HPG solution with conventional physioneal (PYS) and icodextrin (ICO) PD solutions in rats with MetS. Obese type 2 diabetic ZSF1 rats received a daily intraperitoneal injection of PD solutions (10 mL) for 3 months. The peritoneal membrane (PM) function was determined by ultrafiltration (UF), and the systemic responses were determined by profiling blood metabolic substances, cytokines and oxidative status. Tissue damage was assessed by histology. At the end of the 3-month treatment with PD solutions, PM damage and UF loss in both the PYS and ICO groups were greater than those in the HPG group. Blood analyses showed that compared to the baseline control, the rats in the HPG group exhibited a significant decrease only in serum albumin and IL-6 and a minor glomerular injury, whereas in both the PYS and ICO groups, there were more significant decreases in serum albumin, antioxidant activity, IL-6, KC/GRO (CXCL1) and TNF-α (in ICO only) as well as a more substantial glomerular injury compared to the HPG group. Furthermore, PYS increased serum creatinine, serum glucose and urine production. In conclusion, compared to PYS or ICO solutions, the HPG solution had less adverse effects locally on the PM and systemically on distant organs (e.g. kidneys) and the plasma oxidative status in rats with MetS.

Somatostatin Receptor 2 antagonists (SSTR2a) increase glucagon counter-regulation to hypoglycemia in various rodent models of type-1 diabetes mellitus. Here we investigated the efficacy of SSTR2a in improving glucagon counter-regulation in a rat model of type-2 diabetes mellitus (T2DM). For this, male Sprague Dawley rats (n=18) were given a high fat diet for 3 weeks, followed by low-dose streptozotocin exposure (35 mg/kg, IP) to induce T2DM. Rats were then divided into SSTR2a treatment (PRL-2903, 10 mg/kg) or vehicle (n=9 for each) 1-hour before insulin-induced hypoglycemia (3 IU/kg NovoRapid). This process was repeated 1 week later in a cross-over design, with the data pooled over SSTR2a and vehicle treatments. A group of normal-chow-fed rats (n=3) served as nondiabetic controls. Mean blood glucose levels were higher at 20, 30, 40, and 50 minutes post insulin administration in the T2DM rats treated with PRL-2903, as compared to vehicle (p ≤ 0.05). The number of T2DM rats that developed biochemical hypoglycemia (blood glucose ≤ 3.5 mmol/L) tended to be less with PRL-2903 (5/18) vs. vehicle (9/18). Compared with vehicle treatment, PRL-2903 promoted higher plasma glucagon counter-regulation, as indicated by area under curve (AUC) analysis (p < 0.05). Thus, SSTR2a treatment improves the attenuated glucagon response to hypoglycemia in T2DM rats. Disclosure M. Nejad-Mansouri: None. P. Zaree Bavani: None. J. Aiken: None. N.C. DSouza: None. E.G. Hoffman: None. R. Liggins: None. M. Riddell: Advisory Panel; Self; Xeris Pharmaceuticals, Inc. Research Support; Self; Dexcom, Inc. Speaker’s Bureau; Self; Insulet Corporation, Medtronic MiniMed, Inc. Stock/Shareholder; Self; Zucara Therapeutics Inc. Funding National Research Council Canada; Zucara Therapeutics

Hypoglycemia (HG) and fear of HG are well-known problems for people using insulin, impacting quality of life, glycemic control, and health care cost. We evaluated patient perceptions of the unmet need of HG prevention in insulin users, exploring various patient aims in managing HG (Figure 1) via a survey of 637 T1D and T2D patients. Respondents rated the importance of each aim, and their current satisfaction in meeting them with current therapy. Compared to T2D, T1D patients (and also CGM users compared to non-users) had lower satisfaction with status quo for all aims except in managing meals. T1D and T2D placed greatest importance on avoiding waking due to nocturnal hypoglycemia (NH). Avoiding waking at night and reducing anxiety due to NH were identified as areas of high unmet need (low satisfaction, high importance) in both T1D and T2D (particularly those on MDI) while managing exercise and meals were prominent needs in T1D. Although CGM technologies are becoming the standard of care for insulin users, and are a proven tool for warning of HG, CGM users have mixed feelings about HG alerts, especially in NH. Respondents were asked about their interest (4 point “intent to use” scale) in adding a drug to their existing regimen (insulin ± CGM) that would prevent NH. There was strong interest in adjunctive use of a therapy to prevent NH from all groups, and CGM users showed the greatest interest in an adjunctive therapy. Disclosure R. Liggins: None. C. Piche: Board Member; Self; Zucara Therapeutics Inc. Employee; Self; Locemia Solutions. Stock/Shareholder; Self; Beta Bionics, Bigfoot Biomedical, Biolinq, Capillary Biomedical, Inc., Diasome Pharmaceuticals, Inc. M. Riddell: Advisory Panel; Self; Xeris Pharmaceuticals, Inc. Consultant; Self; Lilly Diabetes. Research Support; Self; Dexcom, Inc., Insulet Corporation, Novo Nordisk Inc., Sanofi. Speaker's Bureau; Self; Medtronic MiniMed, Inc., OmniPod. Stock/Shareholder; Self; Zucara Therapeutics Inc. R. Wood: Other Relationship; Self; Multiple companies in the diabetes field (>10 companies). C. Pang: Consultant; Self; dQ&A Market Research, Inc. M. Lafontaine: Consultant; Self; Diasome Pharmaceuticals, Inc., Metronom Health Europe, Montmed, Tolerion, Inc., Zucara Therapeutics Inc. Stock/Shareholder; Self; Locemia Solutions. Other Relationship; Self; 360 Marketing Strategic Services. M. Midmer: Employee; Self; Zucara Therapeutics Inc. Funding The Leona M. and Harry B. Helmsley Charitable Trust

Hemorrhage is the leading cause of preventable death in trauma, and hemorrhage from noncompressible junctional anatomic sites is particularly difficult to control. The current standard is QuikClot Combat Gauze packing, which requires 3 min of compression. We have created a novel dressing with calcium carbonate microparticles that can disperse and self-propel upstream against flowing blood. We loaded these microparticles with thrombin and tranexamic acid and tested their efficacy in a swine arterial bleeding model without wound compression. Anesthetized immature female swine received 5 mm femoral arteriotomies to induce severe junctional hemorrhage. Wounds were packed with kaolin-based QuikClot Combat Gauze (KG), propelled thrombin-microparticles with protonated tranexamic acid (PTG), or a non-propelling formulation of the same thrombin-microparticles with non-protonated tranexamic acid (NPTG). Wounds were not compressed after packing. Each animal then received one 15 mL/kg bolus of hydroxyethyl starch solution followed by Lactated Ringer’s as needed for hypotension (maximum: 100 mL/kg) for up to 3 hours. Survival was improved with PTG (3-hr survival: 8/8, 100%) compared to KG (3/8, 37.5%) and NPTG (2/8, 25%) (p0.05). Thus, in this swine model of junctional arterial hemorrhage, gauze with self-propelled, pro-thrombotic microparticles improved survival and two indicators of hemorrhagic shock when applied without compression, suggesting this capability may enable better treatment of non-compressible junctional wounds.

Background: Glucose is a primary osmotic agent in peritoneal dialysis (PD) solutions, but its long-term use causes structural alteration of the peritoneal membrane (PM). Hyperbranched polyglycerol (HPG) is a promising alternative to glucose. This study was designed to compare the cellular responses of human peritoneal mesothelial cells (HPMCs) to these two different osmotic agents in a hypertonic solution using transcriptome analysis. Methods: Cultured HPMCs were repeatedly exposed to HPG-based or Physioneal 40 (PYS, glucose 2.27%) hypertonic solutions. Transcriptome datasets were produced using Agilent SurePrint G3 Human GE 8 × 60 microarray. Cellular signaling pathways were examined by Ingenuity Pathway Analysis (IPA). Protein expression was examined by flow cytometry analysis and Western blotting. Results: The HPG-containing solution was better tolerated compared with PYS, with less cell death and disruption of cell transcriptome. The levels of cell death in HPG- or PYS- exposed cells were positively correlated with the number of affected transcripts (HPG: 128 at day 3, 0 at day 7; PYS: 1799 at day 3, 212 at day 7). In addition to more affected “biosynthesis” and “cellular stress and death” pathways by PYS, both HPG and PYS commonly affected “sulfate biosynthesis”, “unfolded protein response”, “apoptosis signaling” and “NRF2-mediated oxidative stress response” pathways at day 3. PYS significantly up-regulated HLA-DMB and MMP12 in a time-dependent manner, and stimulated T cell adhesion to HPMCs. Conclusion: The lower cytotoxicity of hypertonic HPG solution is in agreement with its transient and minimal impact on the pathways for the “biosynthesis of cell constituents” and the “cellular stress and death”. The significant up-regulation of HLA-DMB and MMP12 by PYS may be part of its initiation of immune response in the PM.

Glucagon (GCN) helps prevent hypoglycemia when blood glucose levels drop; however, recurrent hypoglycemia attenuates GCN counterregulation to subsequent bouts of hypoglycemia. As somatostatin normally inhibits GCN secretion, we tested the hypothesis that a somatostatin receptor type 2 antagonist (SSTR2a), PRL-2903, improves GCN responses attenuated by recurrent hypoglycemia in healthy rats. Healthy male Sprague-Dawley rats (n=22) were made hypoglycemic on three consecutive days (days 1-3, blood glucose 1.7-2.2 mmol/L for ∼2 h) via exogenous insulin administration (10-, 8- and 5- U/kg of Humulin-R on days 1-3, respectively). GCN levels during hypoglycemia on day 3 were significantly lower than on day 1 (117±47 pg/mL vs. 184±77 [mean±SD] pg/mL; P=0.001), highlighting the role of recurrent hypoglycemia in counterregulatory failure. On day 4, rats were treated with either PRL-2903 (10 mg/kg IP; n=13) or vehicle (n=9) 1 h prior to the induction of hypoglycemia with 5 U/kg of R-insulin. GCN levels during hypoglycemia (i.e., glucose ≤3.5 mmol/L) were 2.5-fold higher (109±55 vs. 44±26 pg/mL; P=0.004) compared to vehicle, and time to reach hypoglycemia was 3.2-fold longer (64±45 vs. 20±10 min; P =0.001), with PRL-2903 pre-treatment. Interestingly, C-peptide levels were also lower (P=0.001) with PRL-2903 (0.35±0.22 ng/mL), compared to vehicle (0.63±0.21 ng/mL), inferring a lower insulin secretion during hypoglycemia with PRL-2903 treatment. In conclusion, our data suggests that SSTR2a improves GCN responses following recurrent hypoglycemia, and that this improvement may be associated with a reduction in insulin secretion in healthy rats. Therefore, SSTR2a treatment may be a useful therapeutic approach to improve GCN counterregulatory responses to hypoglycemia. Disclosure M. Riddell: Speaker's Bureau; Self; Medtronic. Consultant; Self; Eli Lilly and Company, JAEB Center For Health Research, Xeris Pharmaceuticals, Inc.. Research Support; Self; Insulet Corporation. Speaker's Bureau; Self; Insulet Corporation. Advisory Panel; Self; Sanofi. Speaker's Bureau; Self; Ascensia Diabetes Care. Stock/Shareholder; Self; Zucara Theraputics. Other Relationship; Self; JDRF. M. Jahangiriesmaili: None. E.R. Mandel: None. C.A. Greenberg: None. A.M. Pasieka: None. T. Teich: None. O. Chan: None. R.T. Liggins: Employee; Self; Zucara Therapeuytics, Inc..

Granzyme B (GzmB) is a serine protease that has long been thought to function exclusively in lymphocyte-mediated apoptosis. In recent years, this paradigm has been revisited due to the recognition that GzmB accumulates in the extracellular milieu in many autoimmune and chronic inflammatory disorders, and contributes to impaired tissue remodeling due to the cleavage of extracellular matrix proteins. Knockout studies suggest that GzmB-mediated cleavage of decorin (DCN) contributes to impaired collagen fibrillogenesis and remodeling. As DCN is anti-fibrotic and contributes to reduced hypertrophic scarring, GzmB-induced DCN cleavage could play a role in wound healing following burn injury. In the present study, a novel, gel-formulated, first-in-class small-molecule inhibitor of GzmB, VTI-1002, was assessed in a murine model of impaired, diabetic burn wound healing. VTI-1002 exhibited high specificity, potency, and target selectivity. Gel-formulated VTI-1002 was able to penetrate the stratum corneum and was retained in the skin with minimal systemic absorption. Daily topical administration of VTI-1002 gel for 30 days following thermal injury showed significantly accelerated wound closure, increased DCN protein levels, and collagen organization that was translated into significantly increased wound tensile strength compared to controls. Overall, VTI-1002 gel was well-tolerated in vivo and no adverse events were observed. Topical application of VTI-1002 represents a novel therapeutic approach for the treatment of cutaneous burn wounds., Chronic wounds: Gel encourages healing and reduces scarring A promising, recently developed topical treatment prevents detrimental enzyme activity in burn wounds, accelerates healing and reduces scarring. Chronic wounds that do not heal fully and require ongoing medical attention are common in the elderly, obese, and/or diabetic populations, resulting in enormous costs to healthcare services. Recent research indicates that an enzyme called granzyme. (GzmB) accumulates in chronically inflamed wounds, impairing collagen organization and disrupting tissue remodeling. David Granville at the University of British Columbia, Vancouver, Canada, and co-workers trialed a topical gel designed to inhibit GzmB activity in burn injuries in diabetic mice. When applied to the wounds for 30 days, the gel improved wound closure and remodeling while reducing scarring. The gel targeted wounds directly with no effect on surrounding tissues, and no adverse effects were observed during treatment.

Recently, efficacy studies in mice have shown that amine-terminated cationic (CNP) nanoparticulate carriers of DTX offer an improved formulation of the drug for intravesical delivery. It is hypothesized that this improved efficacy may arise from a carrier mediated bladder exfoliation process that removes the urothelial barrier allowing for increased drug uptake into bladder tissue. The objective of this study was to investigate exfoliation processes in fresh pig's bladders (ex vivo) exposed to three cationic polyglycerols with increasing degrees of amination (denoted 350, 580 and 780). The study also compared the tissue depth profile of DTX uptake into these tissues using these different carriers.Aminated polyglycerols were synthesized and characterized in the laboratory with low (CNP-360), medium (CNP-580) and high (CNP-780) levels of amine content. CNP-based DTX solutions and commercial DTX solutions in polysorbate 80 (Taxotere®) were doped with (3)H-radiolabeled DTX and prepared by solvent evaporation from acetonitrile, followed by drying and reconstitution in pH 6.4 buffer. Sections of fresh pig's bladder tissue were clamped into Franz diffusion cells and the urothelial side was exposed to the DTX solutions for 2 h. Tissue sections were then frozen for sectioning by cryotome sectioning and subsequently processed for drug analysis by liquid scintillation counting. Alternatively tissue sections were fixed in 2% glutaraldehyde and 2% paraformaldehyde in 0.1 M sodium cacodylate buffer for the purposes of scanning electron microscopy (SEM).Exposure of the urothelial surface to the amine-terminated polyglycerol solutions resulted in the exfoliation of bladder tissues in a time- and concentration-dependent manner. Exfoliation was significantly more pronounced when using CNPs with a medium or high levels of amination whereas only minor levels of exfoliation were seen with low levels. Following incubation of tissues in Tween-based commercial formulations (Taxotere) of DTX (0.5 mg/mL) the drug was detectable at low levels (10-40 μg/g tissue) in all depths of tissue. Similar drug uptake was observed using the CNP-360 formulation. However drug uptake levels were increased to 60-100 μg/g tissue when samples were incubated with either the CNP-580 or CNP-780 formulations.The use of cationic polyglycerols with higher levels of amine termination allows for an enhanced uptake of DTX into bladder tissues as compared to commercial (Taxotere) formulations. These increased drug levels probably arise from exfoliation processes resulting in a temporary elimination of the urothelial permeability barrier and increased drug penetration into the tissue.

Regular exercise is at the cornerstone of care in type 1 diabetes. However, relative hyperinsulinaemia and a blunted glucagon response to exercise promote hypoglycaemia. Recently, a selective antagonist of somatostatin receptor 2, PRL-2903, was shown to improve glucagon counterregulation to hypoglycaemia in resting streptozotocin-induced diabetic rats. The aim of this study was to test the efficacy of PRL-2903 in enhancing glucagon counterregulation during repeated hyperinsulinaemic exercise.Diabetic rats performed daily exercise for 1 week and were then exposed to saline (154 mmol/l NaCl) or PRL-2903, 10 mg/kg, before hyperinsulinaemic exercise on two separate occasions spaced 1 day apart. In the following week, animals crossed over to the alternate treatment for a third hyperinsulinaemic exercise protocol.Liver glycogen content was lower in diabetic rats compared with control rats, despite daily insulin therapy (p 0.05). Glucagon levels failed to increase during exercise with saline but increased three-to-six fold with PRL-2903 (all p 0.05). Glucose concentrations tended to be higher during exercise and early recovery with PRL-2903 on both days of treatment; this difference did not achieve statistical significance (p 0.05).PRL-2903 improves glucagon counterregulation during exercise. However, liver glycogen stores or other factors limit the prevention of exercise-induced hypoglycaemia in rats with streptozotocin-induced diabetes.

Recently, we have reported that docetaxel (DTX) loaded, amine terminated hyperbranched polyglycerol (HPG-C 8/10 -MePEG-NH 2 ) nanoparticles significantly increased drug uptake in mouse bladder tissues and was the most effective formulation to significantly inhibit tumor growth in an orthotopic model of bladder cancer. The objective of this study was to investigate the effects of HPG-C 8/10 -MePEG-NH 2 nanoparticles on bladder urothelial morphology and integrity, DTX uptake and permeability in bladder tissue and the extent of bladder urothelial recovery following exposure to, and then washout of, HPG-C 8/10 -MePEG-NH 2 nanoparticles. HPG-C 8/10 -MePEG-NH 2 nanoparticles significantly increased the uptake of DTX in both isolated pig bladder as well as in live mouse bladder tissues. Furthermore, HPG-C 8/10 -MePEG-NH 2 nanoparticles were demonstrated to increase the permeability of the urinary bladder wall by causing changes to the urothelial barrier function and morphology through opening of tight junctions and exfoliation of the superficial umbrella cells. These data suggest that exfoliation may be triggered by an apoptosis mechanism, which was followed by a rapid recovery of the urothelium within 24 h post-instillation of HPG-C 8/10 -MePEG-NH 2 nanoparticles. HPG-C 8/10 -MePEG-NH 2 nanoparticles cause significant but rapidly recoverable changes in the bladder urothelial morphology, which we believe may make them suitable for increasing drug permeability of bladder tissue and intravesical drug delivery.

Purpose: The present work describes the development and in vitro and in vivo evaluation of a mucoadhesive nanoparticulate docetaxel (DTX) formulation for intravesical bladder cancer therapy. Experimental Design: Mucoadhesive formulations based on hyperbranched polyglycerols (HPG), hydrophobically derivatized with C8/C10 alkyl chains in the core and modified with methoxy-polyethylene glycol (MePEG) and amine groups in the shell (HPG-C8/10-MePEG-NH2) were synthesized and DTX was loaded into these by a solvent evaporation method. Both low-grade (RT4, MGHU3) and high-grade (UMUC3) human urothelial carcinoma cell lines were treated with various concentrations of DTX formulations in vitro. KU7 cells that stably express firefly luciferase (KU7-luc) were inoculated in female nude mice by intravesical instillation and quantified using bioluminescence imaging. Mice with established KU7-luc tumors were given a single intravesical instillation with PBS, Taxotere (DTX from Sanofi-aventis), and DTX-loaded HPG-C8/10-MePEG and/or HPG-C8/10-MePEG-NH2. Drug uptake was conducted using LC/MS-MS (liquid chromatography/tandem mass spectrometry) and tumor microenvironment and uptake of rhodamine labeled HPGs was assessed. Results: In vitro, all DTX formulations potently inhibited bladder cancer proliferation. However, in vivo, DTX-loaded HPG-C8/10-MePEG-NH2 (mucoadhesive DTX) was the most effective formulation to inhibit tumor growth in an orthotopic model of bladder cancer. Furthermore, mucoadhesive DTX significantly increased drug uptake in mouse bladder tissues. In addition, rhodamine labeled HPG-C8/10-MePEG-NH2 showed enhanced uptake of these nanoparticles in bladder tumor tissues. Conclusions: Our data show promising in vivo antitumor efficacy and provide preclinical proof of principle for the intravesical application of mucoadhesive nanoparticulate DTX formulation in the treatment of bladder cancer. Clin Cancer Res; 17(9); 2788–98. ©2011 AACR.

In this study we report the development and in vitro characterization of paclitaxel (PTX) and docetaxel (DTX) loaded into hydrophobically derivatized hyperbranched polyglycerols (HPGs). Several HPGs derivatized with hydrophobic groups (C 8/10 alkyl chains) (HPG–C 8/10 –OH) and/or methoxy polyethylene glycol (MePEG) chains (HPG–C 8/10 –MePEG) were synthesized. PTX or DTX were loaded into these polymers by a solvent evaporation method and the resulting nanoparticle formulations were characterized in terms of size, drug loading, stability, release profiles, cytotoxicity, and cellular uptake. PTX and DTX were found to be chemically unstable in unpurified HPGs and large fractions (∼80%) of the drugs were degraded during the preparation of the formulations. However, both PTX and DTX were found to be chemically stable in purified HPGs. HPGs possessed hydrodynamic radii of less than 10 nm and incorporation of PTX or DTX did not affect their size. The release profiles for both PTX and DTX from HPG–C 8/10 –MePEG nanoparticles were characterized by a continuous controlled release with little or no burst phase of release. In vitro cytotoxicity evaluations of PTX and DTX formulations demonstrated a concentration-dependent inhibition of proliferation in KU7 cell line. Cellular uptake studies of rhodamine-labeled HPG (HPG–C 8/10 –MePEG 13 –TMRCA) showed that these nanoparticles were rapidly taken up into cells, and reside in the cytoplasm without entering the nuclear compartment and were highly biocompatible with the KU7 cells.

Hyperbranched polyglycerols (HPGs) with hydrophobic cores and derivatized with methoxy poly(ethylene glycol) were synthesized and further functionalized with carboxylate groups to bind and deliver cisplatin. Low and high levels of carboxylate were conjugated to HPGs (HPG-C(8/10)-MePEG(6.5)-COOH(113) and HPG-C(8/10)-MePEG(6.5)-COOH(348)) and their structures were confirmed through NMR and FTIR spectroscopy and potentiometric titration. The hydrodynamic diameter of the HPGs ranged from 5-10 nm and the addition of COOH groups decreased the zeta potential of the polymers. HPG-C(8/10)-MePEG(6.5)-COOH(113) bound up to 10% w/w cisplatin, whereas HPG-C(8/10)-MePEG(6.5)-COOH(348) bound up to 20% w/w drug with 100% efficiency. Drug was released from HPG-C(8/10)-MePEG(6.5)-COOH(113) over 7 days at the same rate, regardless of the pH. Cisplatin release from HPG-C(8/10)-MePEG(6.5)-COOH(348) was significantly slower than HPG-C(8/10)-MePEG(6.5)-COOH(113) at pH 6 and 7.4, but similar at pH 4.5. Release of cisplatin into artificial urine was considerably faster than into buffer. Carboxylated HPGs demonstrated good biocompatibility, and drug-loaded HPGs effectively inhibited proliferation of KU-7-luc bladder cancer cells.

In this study, we synthesized and characterized two methoxy poly(ethylene glycol)-block-poly(caprolactone) (MePEG-b-PCL) amphiphilic diblock copolymers, both based on MePEG with a molecular weight of 5000 g/mol (114 repeat units) and PCL block lengths of either 19 or 104 repeat units. Nanoparticles were formed from these copolymers by a nanoprecipitation and dialysis technique. The MePEG(114)-b-PCL(19) copolymer was water soluble and formed micelles that had a hydrodynamic diameter of 40 nm at all copolymer concentrations tested, and displayed a relatively low core microviscosity. The practically water insoluble MePEG(114)-b-PCL(104) copolymer formed nanoparticles with a larger hydrodynamic diameter, which was dependent on copolymer concentration, and possessed a higher core microviscosity than the MePEG(114)-b-PCL(19) micelles, characteristic of nanospheres. The micelles solubilized a maximum of 1.6% w/w of the hydrophobic anticancer agent, paclitaxel (PTX), and released 92% of their drug payload over 7 days, as compared to the nanospheres, which solubilized a maximum of 3% w/w of PTX and released 60% over the same period of time. Both types of nanoparticles were found to be hemocompatible, causing only minimal hemolysis and no changes in plasma coagulation times as compared to control. Upon in vitro incubation in human plasma, PTX solubilized by micelles had a plasma distribution similar to free drug. The majority of PTX was associated with the lipoprotein deficient plasma (LPDP) fraction, which primarily consists of albumin and alpha-1-acid glycoprotein. In contrast, nanospheres were capable of retaining more of the encapsulated drug with significantly less PTX partitioning into the LPDP fraction.

Neuraminidase inhibitors (NAIs), including the most frequently prescribed oral therapeutic oseltamivir, play a critical role in the control of severe influenza virus (IFV) infections. However, recent reports of spread of an oseltamivir-resistant H1N1 pandemic strain in individuals who have never been exposed to oseltamivir highlight an urgent need for new antivirals against NAI-resistant IFVs. Difluorosialic acids (DFSAs) are a novel class of anti-IFV NAIs designed based on the mechanism of action of IFV NA, and distinguished by their covalent inhibition mode and their high structural similarity to the natural substrate, sialic acid. These characteristics should render the development of resistance a less rapid process. In this report, we evaluated the relative propensity of influenza A virus (IFV-A) NA to develop resistance against the DFSA class of inhibitor by passaging IFV-A strains in vitro in the presence of either oseltamivir or a representative DFSA (FeqGuDFSA). All the passage-selected lines gained mutations in hemagglutinin. Among the 12 oseltamivir-resistant passaged lines, five gained NA mutations and four of these were the well-defined H275Y mutation that causes oseltamivir resistance. In contrast, out of 15 DFSA-passaged lines, only 2 lines gained NA mutations. Further, NA inhibition assays indicated that these mutations did not change the sensitivity of NA to DFSA and thus the resistance to DFSA was not conferred by these NA mutations. These results strongly suggest that, compared to oseltamivir, IFV is less prone to development of resistance against DFSAs through NA mutations.

Difluorosialic acids (DFSAs) are potent inhibitors of viral neuraminidase that demonstrate activity against oseltamivir- and zanamivir-resistant strains of influenza. Unfortunately, low oral bioavailability precludes their development as second generation neuraminidase inhibitors for treating influenza as this leaves them unsuitable for use in an oral formulation. Herein is described the preparation of a series of DFSA prodrugs designed to increase oral bioavailability. These prodrugs were evaluated using a snapshot PK screen and stability tests, with successful candidates being further assessed with a full pharmacokinetic workup. These new prodrugs increased oral bioavailability by up to three times that seen for the parent DFSAs.

A series of short block length methoxy poly(ethylene glycol)-block-poly(caprolactone) diblock copolymers was synthesized and characterized in order to assess the potential of these copolymers as a micellar drug-delivery system. Varying the caprolactone:MePEG weight ratio in the reaction mixture allowed the synthesis of diblock copolymers with a MePEG molecular weight of 750 g/mol and PCL block lengths of 2, 5 or 10 repeat units. Phase diagrams of aqueous solutions of the copolymers were constructed which displayed characteristic cloud points and Krafft points. As the degree of polymerization of PCL increased, critical micelle concentration (CMC) values decreased from 6.97×10 −1 to 3.38×10 −3 g/l, partition equilibrium coefficients ( K v ) increased from 1.09×10 4 to 22.2×10 4 , and hydrodynamic diameters increased from 12.2 to 19.5 nm. The micelle morphology was determined to be spherical by transmission electron microscopy.

A number of hypersensitivity reactions have been attributed to the presence of Cremophor((R)) EL in the current formulation for paclitaxel. This has led to the development of formulations for paclitaxel employing polyether-polyester diblock copolymers as micelle forming carriers. Diblock copolymers of methoxypolyethylene glycol-block-poly(D,L-lactide) (MePEG:PDLLA) were synthesized from monomers of D,L-lactide and MePEG by a ring opening bulk polymerization in the presence of stannous octoate. Up to 25% paclitaxel could be loaded into matrices of MePEG:PDLLA (60:40, MePEG molecular weight of 2000) using the solution casting method. Dissolution of paclitaxel/copolymer matrices in aqueous media resulted in complete solubilization of paclitaxel within the hydrophobic PDLLA core of the micelles. This review article describes the synthetic reaction conditions influencing the degree of conversion of monomer to copolymer, thermal properties, critical micelle concentrations of copolymers, methods of incorporation of paclitaxel into copolymer matrices and subsequent constitution in aqueous media and biological evaluations of micellar paclitaxel.

Microspheres were prepared from poly(L-lactic acid) polymers having molecular weights between 500 and 50k g/mol. The polymers were synthesized using two initiator molecules, L-lactic acid oligomer (PLLA-LA) or stearyl alcohol (PLLA-SA). For both PLLA-LA and PLLA-SA polymers, glass (Tg) and melting (Tm) transition temperatures and enthalpy of melting all increased as the polymer molecular weight increased. PLLA-SA showed the greatest change in Tg (-13 to 54 degrees C) as molecular weight increased from 500 to 10k x g/mol, compared to 25 to 55 degrees C for PLLA-LA polymers. Changes in Tm and enthalpy of melting with increasing molecular weight were similar for both PLLA-LA and PLLA-SA. Paclitaxel release from 30% paclitaxel loaded microspheres in the size range of 50-90 microm was affected by these changes in polymer properties as molecular weight increased. As the molecular weight increased from 2k to 50k x g/mol the amount of drug released from microspheres over 14 days decreased from 76 to 11% of the initial drug load. The release profiles were consistent with a diffusion controlled mechanism provided a two-compartment model was employed. According to this model, the total amount of 'available' drug (compartment 1) was released by diffusion in 14 days while the remainder (compartment 2) was confined within the polymeric matrix and could not diffuse out at a measurable rate. Following the in vitro release study, microsphere made from 2k-10k g/mol polymers showed significant signs of disintegration whereas 50k x g/mol polymer microspheres remained intact.

Adding to the Antiviral Arsenal The envelope of influenza virus contains two immunodominant glycoproteins: hemagglutinin and neuraminidase (NA). Existing antivirals like zanamivir (Relenza) and oseltamivir (Tamiflu) target NA; however, the development of drug resistance is a problem. Kim et al. (p. 71 , published online 21 February) now report a different class of NA inhibitors. NA catalyzes the removal of sialic acids from the surface of host cells to initiate entry. Discovery of a NA–sialic acid intermediate led to the production of sialic acid analogs that bound covalently to NA and inhibited its enzymatic activity. These compounds showed activity against a wide variety of influenza strains, inhibited viral replication in cell culture, and were able to protect mice against influenza infection. Protection of mice was equivalent to protection seen from zanamivir. Moreover, the compounds showed activity against drug-resistant strains in vitro. These compounds represent a potentially useful addition to the arsenal of antivirals used to treat influenza infection.

When this Letter was first published the author, Tom Wennekes, was omitted from the authorship list. The correct authorship is printed above.