USP Standardized Mixtures of Bovine, Ovine and Porcine Heparin Exhibit Comparable Biologic Effects to Referenced Single Sourced Heparins and May be Interchangeable,

Introduction: Unfractionated heparin (UFH) is the first line anticoagulant for the management of medical indications. UFH complexes with antithrombin to produce strong inhibition of thrombin and factor Xa. The UFHs are standardized using USP compliant amidolytic anti-Xa and IIa methods in defined conditions. Clinically used UFH is solely sourced from porcine mucosal tissue. Because of the shortage of porcine tissue and the African Swine Fever, the supply chain of this anticoagulant is compromised. Thus, there is a need for resourcing of this anticoagulant. Bovine and ovine mucosal sources represent alternate material for production of UFH. Previous studies have shown that bovine and ovine UFH exhibit anticoagulant effects which can be standardized by using the USP method. Additionally, the standardized heparins from various sources can be blended and their potency can be adjusted to exhibit comparable effects as the single sourced UFH. The purpose of this study is to evaluate the pharmacologic profile of the blended heparin and compare these activities to that of the single sourced porcine, ovine and bovine heparins. Methods: Two groups of heparins were evaluated in this study, porcine, ovine, bovine, and the blended heparin in gravimetric measurements (ug/ml) and these same four in potency adjusted measurements (U/ml). The pharmacologic profiles of the heparins in this study were investigated via global anticoagulant assays and anti-protease assays performed in plasma. Clot based assays such as the activated partial thromboplastin time (aPTT) and thrombin time (TT) were used to study the anticoagulant effects of the single source and blended heparins. The amidolytic anti-Xa and IIa assays were used to assess the inhibitory effects of these heparins on these proteases. USP compliant anti-Xa and IIa assays were used to determine potencies of the various heparins. Protamine sulfate (PS) neutralization studies were performed to evaluate the reversal of anticoagulant effects in each of the heparins. Results: The aPTT assay showed that at final concentrations of 5 ug/ml and 2.5 ug/ml porcine heparin significantly (p < .01) prolonged the aPTT compared to ovine, bovine, and blended heparins. When studied with potency adjusted heparins, all heparins demonstrated comparable aPTT values at all concentrations (U/ml). The TT assay showed that porcine and ovine heparins prolonged the TT at 1.25 ug/ml compared to bovine and blended heparins. When studied with potency adjusted heparins, all heparins demonstrated comparable TT values at all concentrations (U/ml). The anti-Xa assay showed that at all final concentrations between 10 ug/ml and 0.625 ug/ml porcine, ovine, and blended heparins produced significantly (p <.001) stronger Xa inhibition than bovine heparin. When studied with potency adjusted heparins, all heparins demonstrated comparable anti-Xa inhibition at all concentrations (U/ml). The anti-IIa assay showed that at final concentrations 2.5 ug/ml, 1.25 ug/ml, and 0.625 ug/ml porcine and ovine heparins produced significantly (p < .05) stronger IIa inhibition than bovine heparin. When studied with potency adjusted heparins, all heparins demonstrated comparable anti-IIa inhibition at all concentrations (U/ml). The USP compliant anti-Xa assay with gravimetric heparins showed potencies of 201, 201, 150, and 184 U for porcine, ovine, bovine, and blended heparins respectively. The USP compliant anti-Xa assay with potency adjusted heparins showed comparable potencies for all four heparins. The USP compliant anti-IIa assay with gravimetric heparins showed potencies of 204, 196, 127, and 167 U for porcine, ovine, bovine, and blended heparins respectively. The USP compliant anti-IIa assay with potency adjusted heparins showed comparable potencies for all four heparins. The protamine sulfate neutralization studies demonstrated complete neutralization at all concentrations for all of the potency adjusted heparins in the aPTT, TT, anti-Xa, and anti-IIa assays. Conclusion: These studies support the hypothesis that a blended heparin product from bovine, ovine, and porcine tissue, when standardized in USP unit-equivalent proportions, exhibits a comparable anticoagulant profile to the single species heparins. These findings suggest that there is a potential for development of blended heparin to stabilize supply chain of this important anticoagulant and warrant clinical validation. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Protamine Sulfate Is a Potent Inhibitor of Human Papillomavirus InfectionIn Vitro and In Vivo

Human papillomavirus (HPV) infections are transmitted through sexual or other close contact and are etiologically associated with epithelial warts, papillomas, and intraepithelial lesions that may progress to cancer. Indeed, 4.8% of the global cancer burden is linked to HPV infection. Highly effective vaccines protect against two to nine of the most medically important HPV genotypes; yet vaccine uptake is inadequate and/or cost prohibitive in many settings. With HPV-related cancer incidence expected to rise over the coming decades, there is a need for effective HPV microbicides. Herein we demonstrate the strong inhibitory activity of the heparin-neutralizing drug protamine sulfate (PS) against HPV infection. Pretreatment of cells with PS greatly reduced infection regardless of HPV genotype or virus source. Vaginal application of PS prevented infection of the murine genital tract by HPV pseudovirions. Time-of-addition assays where PS was added to cells before infection, during infection, or after viral attachment demonstrated strong inhibitory activities on early infection steps. No effect on virus infection was found for cell lines deficient in heparan sulfate expression, suggesting that PS binds to heparan sulfate on the cell surface. Consistent with this, prophylactic PS exposure prevented viral attachment, including under low pH conditions akin to the human vaginal tract. Our findings suggest PS acts dually to prevent HPV infection: prophylactic treatment prevents HPV attachment to host cells and post-attachment administration alters viral entry. Clinical trials are warranted to determine whether protamine-based products are effective as topical microbicides against genital HPVs.

Functional and histologic imaging of urinary bladder wall after exposure to psychological stress and protamine sulfate

To quantify the urinary bladder wall T1 relaxation time (T1) before and after the instillation contrast mixture in rats previously subjected to water avoidance stress (WAS) and/or acute exposure to protamine sulfate (PS). Female Wistar rats were randomized to receive either sham (control) or 1 h of WAS for ten consecutive days before the evaluation of nocturnal urination pattern in metabolic cages. T1 mapping of urinary bladder wall at 9.4 T was performed pre- and post- instillation of 4 mM Gadobutrol in a mixture with 5 mM Ferumoxytol. Subsequently, either T1 mapping was repeated after brief intravesical PS exposure or the animals were sacrificed for histology and analyzing the mucosal levels of mRNA. Compared to the control group, WAS exposure decreased the single void urine volume and shortened the post-contrast T1 relaxation time of mucosa- used to compute relatively higher ingress of instilled Gadobutrol. Compromised permeability in WAS group was corroborated by the urothelial denudation, edema and ZO-1 downregulation. PS exposure doubled the baseline ingress of Gadobutrol in both groups. These findings confirm that psychological stress compromises the paracellular permeability of bladder mucosa and its non-invasive assay with MRI was validated by PS exposure.