@inproceedings{bal2019vivo,
title = {In Vivo Endothelial Uptake of Nanoparticles: Impact of Disturbed Flow and Degraded Glycocalyx},
author = {Nandita Bal and Ming Cheng and Rajiv Kumar and Srinivas Sridhar and Eno E Ebong},
year = {2019},
date = {2019-01-01},
booktitle = {2019 AIChE Annual Meeting},
organization = {AIChE},
abstract = {Statement of Purpose: New and more effective therapies for atherosclerosis-based cardiovascular disease should target early stages of the diseases and specific vascular sites where disease occurs.1 The initiation and localization of atherosclerotic plaques has been linked to the dysfunction of the endothelial glycocalyx (GCX). The GCX breaks down, resulting in compromised endothelial barrier function and an increase in vascular permeability.2 This allows lipids and inflammatory cells to penetrate vessel walls, and at the same time can be leveraged for targeted therapeutic delivery. In previous cell culture studies, enzyme-induced GCX degradation resulted in significantly increased endothelial cell uptake of nanoparticle vehicles that are designed for drug delivery, compared to the effects of intact GCX.3,4 The study presented in this abstract was designed to assess if the cell culture findings translate to selective nanoparticle uptake in animals. Specifically, it was determined if increased nanoparticle uptake occurs in animal endothelial cells that have degraded GCX. The first objective of this animal study was to identify vessel regions with intact versus degraded GCX, and confirm that circulating nanoparticles localize selectively at regions of GCX dysfunction. The second objective was to promote endothelial cell surface-specific localization of these nanoparticles by targeting the intracellular adhesion molecule (ICAM) which is upregulated in pre-atherosclerotic disturbed flow conditions.5
Methods: Mouse models of endothelial dysfunction apply partial ligation of the left carotid artery (LCA) to model acute disturbed flow in the mice, which has been reported to induce endothelial dysfunction.6,7 Seven C57BL/6 mice at 4 weeks of age underwent this partial LCA ligation surgery. Polymer- and biotin-coated 10 nm gold nanospheres (GNS) were administered to the mice at day 26 after LCA ligation. In the case of targeted delivery to the endothelial cell surface, an anti-ICAM peptide was conjugated to the GNS surface before it was administered to the mice. The animals were euthanized 2 days after receiving the GNS without or conjugated with anti-ICAM. The LCA and right carotid artery (RCA) were separately cryopreserved and sectioned onto slides. GCX was imaged after incubating LCA and RCA sections with antibody to block GNS, followed by biotinylated wheat germ agglutinin and horseradish peroxidase conjugated to streptavidin. GNS were imaged after incubation with horseradish peroxidase conjugated to streptavidin. We then applied a fluorescent reagent that reacts with horseradish peroxidase. The blood vessels were imaged by fluorescence microscopy and analyzed using ImageJ for GCX coverage and GNS uptake.

Results: The partial LCA ligation model achieved the goal of creating a vessel with disturbed flow. The model also provided a convenient comparison with a healthy RCA experiencing streamlined flow. The vessel walls of the LCA exhibited a more discontinuous GCX layer on the intima as compared to the RCA, decreasing from 76.3 ± 10.2 % in the RCA to 21.2 ± 5.9 % in the LCA. This observable dysfunction correlated to increased nanoparticle uptake, as the LCA took in approximately 2.5-fold more GNS than the RCA did, based on the fluorescence signal detected in the histology images. The studies to improve endothelial cell surface-specific localization of these nanoparticles by targeting ICAM are still ongoing.

Conclusions: A partial LCA ligation was performed to acutely disturb blood flow in a mouse vessel and observe resultant endothelial GCX dysfunction as well as passive targeting of GNS to affected areas. The affected LCA exhibited lack of continuous GCX layer, as well as increased localization of plolymer-coated GNS that are designed to deliver drug therapies. These results indicate that vessel and GCX dysfunction, both precursors of atherosclerosis and cardiovascular disease, can be induced in a mouse model to study targeted drug delivery. Passive nanoparticle uptake differences between the healthy RCA and disturbed LCA indicate a role of GCX infiltration of nanoparticles to the endothelial cells. The ongoing investigation will determine the effectiveness of active targeting with ICAM to localize these nanoparticles to the endothelial cell surface. This strategy of targeting dysfunctional vessels based on the GCX offers a new approach in cardiovascular disease therapy and prevention.

Acknowledgements: We appreciate funding from National Institutes of Health (K01 HL125499) and the Northeastern University Provost’s Tier 1 Grant.

References:

Weinbaum, S.; et. al, Annu Rev Biomed Eng 2007, 9,121-167.
Becker, B. et. al, Br J Clin Pharmacol 2015, 80, 389-402.
Cheng, et. al, Int. J. Nanomed 2016, 21, 3305-3315.
Cheng, et. al, Int. J. Nanomed 2019, 14, 319-333.
Nakashima et. al, Arteriosclerosis, Thrombosis, and Vascular Biology 1998, 18, 842-851.
Kumar, S.; et. al, J. Lab. Invest. 2017, 97, 935-945
Mitra, et. al, Trans. Med. Comm. 2018, 3-10.},
keywords = {Nanomedicine},
pubstate = {published},
tppubtype = {inproceedings}
}

@inproceedings{baldwin2019nanoformulationc,
title = {NANOFORMULATION OF TALAZOPARIB SUPPRESSES TUMOR GROWTH AND ASCITES IN A DISSEMINATED CANCER MODEL},
author = {Paige Baldwin and Anders Ohman and Jamie Medina and Daniela Dinulescu and Srinivas Sridhar},
year = {2019},
date = {2019-01-01},
booktitle = {CLINICAL CANCER RESEARCH},
volume = {25},
number = {22},
pages = {198--198},
organization = {AMER ASSOC CANCER RESEARCH 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA~…},
abstract = {Talazoparib, a potent PARP inhibitor (PARPi), induces synthetic lethality in BRCA-deficient cancers making it an attractive candidate for ovarian cancer treatment. However, its potency lends itself to side effects associated more closely with traditional chemotherapeutics than other clinically approved PARPi's. We sought to formulate Talazoparib in a nanoparticle delivery system such that the drug could be administered intraperitoneally, localizing the entire dose at the disease site, to increase therapeutic efficacy and minimize toxicity. NanoTalazoparib was formulated and characterized and found to have a mean diameter of 70 nm and a neutral surface charge. Talazoparib and NanoTalazoparib were tested on a panel of murine tubal and human HGSOC cell lines and dose response compared to the first clinically approved PARPi, Olaparib. Dose response data indicated all cell lines were more sensitive to Talazoparib and NanoTalazoparib than Olaparib and all lines showed the same sensitivity to nanoformulations as free drugs. The human cell lines had various BRCA mutations and deletions, as well as a homologous recombination proficient (HRP) line, however, the HRP line was more sensitive to treatment than some HRD lines. Therapeutic efficacy was tested in vivo in a murine cancer model that mimics disseminated peritoneal disease. NanoTalazoparib 3X weekly for 8 weeks did not shrink tumors but resulted in tumor growth inhibition of 64% while an equivalent dose of oral Talazoparib only resulted in 34% growth inhibition. NanoTalazoparib suppressed the average volume of ascites at the study endpoint by 3.45 times more than oral Talazoparib. H&E staining of the tissues indicated no significant toxicity to the organs of the mononuclear phagocyte system. These results indicate that NanoTalazoparib can be used to localize PARPi therapy to the peritoneal cavity for disseminated late stage ovarian cancer treatment. Our data suggests that NanoTalazoparib could be utilized to delay the formation of tumor ascites for women with HR-deficient disease. While NanoTalazoparib did not effectively treat the disseminated disease at this dose, it may have clinical utility, either in combination with other therapies or as a maintenance therapy. Preclinical data indicates PARP inhibitors potentiate damage when combined with other cytotoxic treatments, however, in the clinic this has resulted in enhanced toxicity, forcing dose reduction and delay. The IP administration of NanoTalazoparib may provide a route to bypass some of the toxicities that have plagued combination treatments.

Supported in part by Rivkin Foundation and CDMRP Ovarian Cancer Research Program

Citation Format: Paige Baldwin, Anders Ohman, Jamie Medina, Daniela Dinulescu, Srinivas Sridhar. NANOFORMULATION OF TALAZOPARIB SUPPRESSES TUMOR GROWTH AND ASCITES IN A DISSEMINATED CANCER MODEL [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr NT-087.

©2019 American Association for Cancer Research.},
keywords = {Nanomedicine},
pubstate = {published},
tppubtype = {inproceedings}
}

@inproceedings{kunjachan2018best,
title = {BEST IN PHYSICS (THERAPY): Enhanced Drug Delivery by Nanoparticle and Radiation-Mediated Tumor Vascular Modulation},
author = {S Kunjachan and S Kotb and R Kumar and R Pola and M Pechar and F Gremse and R Taleei and F Trichard and V Motto-Ros and L Sancey and others},
year = {2018},
date = {2018-01-01},
booktitle = {MEDICAL PHYSICS},
volume = {45},
number = {6},
pages = {E535--E535},
organization = {WILEY 111 RIVER ST, HOBOKEN 07030-5774, NJ USA},
keywords = {Nanomedicine},
pubstate = {published},
tppubtype = {inproceedings}
}

@inproceedings{belz2017sustainedb,
title = {Sustained release of PARP inhibitor Talazoparib and chemotherapeutic Docetaxel from modified brachytherapy spacers for treatment of breast and prostate cancer},
author = {Jodi Belz and Noelle Castilla Ojo and Paige Baldwin and Rajiv Kumar and Anne van de Ven and Karen Liby and Robert Cormack and Mike Makrigiorgos and Srinivas Sridhar},
year = {2017},
date = {2017-01-01},
booktitle = {CANCER RESEARCH},
volume = {77},
organization = {AMER ASSOC CANCER RESEARCH 615 CHESTNUT ST, 17TH FLOOR, PHILADELPHIA, PA~…},
abstract = {Sustained localized delivery of cancer therapeutics is a safe and effective unique option for local control of tumors. Here we report a novel biodegradable implant with the capability to encapsulate different therapeutics, molecular agents, or nanoparticles for local intratumoral delivery. We have successfully demonstrated in vivo the delivery of PARP inhibitor Talazoparib to treat Brca1-mutated cancers and Docetaxel to treat localized or recurring prostate cancers. This one-time intratumoral injection provides a safe vehicle for the sustained release of PARP inhibitor Talazoparib and chemotherapeutic Docetaxel in contrast to low bioavailability and toxicity associated with oral or systemic delivery.

Methods: Biodegradable implants of 1-2mm length and 0.8mm diameter were loaded with ~50μg Talazoparib for BRCA1-mutated breast cancer studies and ~500μg Docetaxel (DTX) for prostate cancer studies. The implants were characterized in vitro using SEM and HPLC, and the release kinetic studies were carried out in PBS buffer (pH 6.0) at 37°C. The IC50's were determined using an MTS assay in breast cancer cell lines derived from Brca1 Co/Co; MMTV-Cre; p53+/−mice, W0069 and W780, and human-derived prostate cancer, PC3. In vivo studies were carried out in Brca1 Co/Co; MMTV-Cre; p53+/− spontaneous tumored mice for breast cancer studies. Subcutaneous PC3 tumors were xenografted in nude mice. Prostate cancer studies were done with and without radiation. Drug-loaded implants were injected once intratumorally using an 18G brachytherapy needle.

Results: The release profile of the drug from the implant in buffer showed a highly sustained release for multiple weeks at therapeutically relevant doses for both docetaxel and Talazoparib loading implants. Breast cancer cell lines W0069 and W780 were highly sensitive to Talazoparib, most likely due to Brca1 mutation. Following a one-time intratumoral implantation of Talazoparib, tumors reduced in size by an average of 50%, while untreated tumors increased ~5X in size. Talazoparib dosing appeared to be well tolerated by the mice. Docetaxel implants proved to be an effective method for prostate cancer in vivo with no significant weight loss observed. The local docetaxel spacer group showed sustained tumor inhibition compared to empty implants and an equivalent DTX dose given systemically. At 40 days 89% survival was observed for mice treated with localized DTX implants compared with 0% in all other treatment groups. Histology samples were taken from sacrificed mice and immunohistochemistry are currently underway.

Conclusions: Sustained local release of therapeutically relevant doses of Talazoparib and Docetaxel were observed in vitro and in vivo. Therapeutics-loaded implants represent a novel delivery route that are well-tolerated. Sustained release of Talazoparib appears to amplify the therapeutic efficacy of PARP inhibition in BRCA1 mutated breast cancers and sustained release of Docetaxel is an effective chemotherapy option alone or in combination with radiation therapy. These results laid a strong foundation for the use of localized biodegradable implants for the treatment of breast and prostate cancer.

This work was supported by the Army- W81XWH-14-1-0092, Breast Cancer Research Foundation and Northeastern University–Dana Farber Cancer Institute collaborative grant.

Citation Format: Jodi Belz, Noelle Castilla Ojo, Paige Baldwin, Rajiv Kumar, Anne van de Ven, Karen Liby, Robert Cormack, Mike Makrigiorgos, Srinivas Sridhar4. Sustained release of PARP inhibitor Talazoparib and chemotherapeutic Docetaxel from modified brachytherapy spacers for treatment of breast and prostate cancer. [abstract]. In: Proceedings of the AACR Special Conference on Engineering and Physical Sciences in Oncology; 2016 Jun 25-28; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2017;77(2 Suppl):Abstract nr B30.},
keywords = {Nanomedicine},
pubstate = {published},
tppubtype = {inproceedings}
}