@article{mantooth_hancock_thompson_varghese_meritet_vrabel_hu_zaharoff_2024, title={Characterization of an Injectable Chitosan Hydrogel for the Tunable, Localized Delivery of Immunotherapeutics}, volume={10}, ISSN={["2373-9878"]}, url={https://doi.org/10.1021/acsbiomaterials.3c01580}, DOI={10.1021/acsbiomaterials.3c01580}, abstractNote={Localized delivery of immunotherapeutics within a tumor has the potential to reduce systemic toxicities and improve treatment outcomes in cancer patients. Unfortunately, local retention of therapeutics following intratumoral injection is problematic and is insufficiently considered. Dense tumor architectures and high interstitial pressures rapidly exclude injections of saline and other low-viscosity solutions. Hydrogel-based delivery systems, on the other hand, can resist shear forces that cause tumor leakage and thus stand to improve the local retention of coformulated therapeutics. The goal of the present work was to construct a novel, injectable hydrogel that could be tuned for localized immunotherapy delivery. A chitosan-based hydrogel, called XCSgel, was developed and subsequently characterized. Nuclear magnetic resonance studies were performed to describe the chemical properties of the new entity, while cryo-scanning electron microscopy allowed for visualization of the hydrogel's cross-linked network. Rheology experiments demonstrated that XCSgel was shear-thinning and self-healing. Biocompatibility studies, both in vitro and in vivo, showed that XCSgel was nontoxic and induced transient mild-to-moderate inflammation. Release studies revealed that coformulated immunotherapeutics were released over days to weeks in a charge-dependent manner. Overall, XCSgel displayed several clinically important features, including injectability, biocompatibility, and imageability. Furthermore, the properties of XCSgel could also be controlled to tune the release of coformulated immunotherapeutics.}, number={2}, journal={ACS BIOMATERIALS SCIENCE & ENGINEERING}, author={Mantooth, Siena M. and Hancock, Asher M. and Thompson, Peter M. and Varghese, P. J. George and Meritet, Danielle M. and Vrabel, Maura R. and Hu, Jingjie and Zaharoff, David A.}, year={2024}, month={Jan}, pages={905–920} }
 @article{vrabel_schulman_gillam_mantooth_nguyen_zaharoff_2023, title={Focal Cryo-Immunotherapy with Intratumoral IL-12 Prevents Recurrence of Large Murine Tumors}, volume={15}, ISSN={["2072-6694"]}, DOI={10.3390/cancers15082210}, abstractNote={Focal ablation technologies are routinely used in the clinical management of inoperable solid tumors but they often result in incomplete ablations leading to high recurrence rates. Adjuvant therapies, capable of safely eliminating residual tumor cells, are therefore of great clinical interest. Interleukin-12 (IL-12) is a potent antitumor cytokine that can be localized intratumorally through coformulation with viscous biopolymers, including chitosan (CS) solutions. The objective of this research was to determine if localized immunotherapy with a CS/IL-12 formulation could prevent tumor recurrence after cryoablation (CA). Tumor recurrence and overall survival rates were assessed. Systemic immunity was evaluated in spontaneously metastatic and bilateral tumor models. Temporal bulk RNA sequencing was performed on tumor and draining lymph node (dLN) samples. In multiple murine tumor models, the addition of CS/IL-12 to CA reduced recurrence rates by 30–55%. Altogether, this cryo-immunotherapy induced complete durable regression of large tumors in 80–100% of treated animals. Additionally, CS/IL-12 prevented lung metastases when delivered as a neoadjuvant to CA. However, CA plus CS/IL-12 had minimal antitumor activity against established, untreated abscopal tumors. Adjuvant anti-PD-1 therapy delayed the growth of abscopal tumors. Transcriptome analyses revealed early immunological changes in the dLN, followed by a significant increase in gene expression associated with immune suppression and regulation. Cryo-immunotherapy with localized CS/IL-12 reduces recurrences and enhances the elimination of large primary tumors. This focal combination therapy also induces significant but limited systemic antitumor immunity.}, number={8}, journal={CANCERS}, author={Vrabel, Maura R. and Schulman, Jacob A. and Gillam, Francis B. and Mantooth, Siena M. and Nguyen, Khue G. and Zaharoff, David A.}, year={2023}, month={Apr} }
 @article{nguyen_mantooth_vrabel_zaharoff_2022, title={Intranasal Delivery of Thermostable Subunit Vaccine for Cross-Reactive Mucosal and Systemic Antibody Responses Against SARS-CoV-2}, volume={13}, ISSN={["1664-3224"]}, DOI={10.3389/fimmu.2022.858904}, abstractNote={Despite the remarkable efficacy of currently approved COVID-19 vaccines, there are several opportunities for continued vaccine development against SARS-CoV-2 and future lethal respiratory viruses. In particular, restricted vaccine access and hesitancy have limited immunization rates. In addition, current vaccines are unable to prevent breakthrough infections, leading to prolonged virus circulation. To improve access, a subunit vaccine with enhanced thermostability was designed to eliminate the need for an ultra-cold chain. The exclusion of infectious and genetic materials from this vaccine may also help reduce vaccine hesitancy. In an effort to prevent breakthrough infections, intranasal immunization to induce mucosal immunity was explored. A prototype vaccine comprised of receptor-binding domain (RBD) polypeptides formulated with additional immunoadjuvants in a chitosan (CS) solution induced high levels of RBD-specific antibodies in laboratory mice after 1 or 2 immunizations. Antibody responses were durable with high titers persisting for at least five months following subcutaneous vaccination. Serum anti-RBD antibodies contained both IgG1 and IgG2a isotypes suggesting that the vaccine induced a mixed Th1/Th2 response. RBD vaccination without CS formulation resulted in minimal anti-RBD responses. The addition of CpG oligonucleotides to the CS plus RBD vaccine formulation increased antibody titers more effectively than interleukin-12 (IL-12). Importantly, generated antibodies were cross-reactive against RBD mutants associated with SARS-CoV-2 variants of concern, including alpha, beta and delta variants, and inhibited binding of RBD to its cognate receptor angiotensin converting enzyme 2 (ACE2). With respect to stability, vaccines did not lose activity when stored at either room temperature (21-22°C) or 4°C for at least one month. When delivered intranasally, vaccines induced RBD-specific mucosal IgA antibodies, which may protect against breakthrough infections in the upper respiratory tract. Altogether, data indicate that the designed vaccine platform is versatile, adaptable and capable of overcoming key constraints of current COVID-19 vaccines.}, journal={FRONTIERS IN IMMUNOLOGY}, author={Nguyen, Khue G. and Mantooth, Siena M. and Vrabel, Maura R. and Zaharoff, David A.}, year={2022}, month={May} }
 @article{mantooth_zaharoff_mantooth_2021, title={INJECTABLE CHITOSAN HYDROGEL FOR LOCALIZED DELIVERY OF IMMUNE CHECKPOINT INHIBITORS}, volume={9}, ISSN={["2051-1426"]}, DOI={10.1136/jitc-2021-SITC2021.259}, abstractNote={BackgroundSystemic delivery of checkpoint inhibitors risks the development of immune-related adverse events (irAEs) in up to 85% of patients.1 Localized delivery methods with slow-release kinetics have the potential to avoid systemic exposure and reduce irAEs. Direct tumor injection is extremely difficult, as saline-based solutions are rapidly excluded from the high-pressure tumor environment. Utilizing hydrogels as a delivery medium and local depot can address this shortcoming. To this end, we developed an injectable chitosan-based hydrogel for intratumoral delivery of checkpoint antibodies.}, journal={JOURNAL FOR IMMUNOTHERAPY OF CANCER}, author={Mantooth, Siena and Zaharoff, David and Mantooth, Siena}, year={2021}, month={Nov}, pages={A281–A281} }
 @article{vrabel_zaharoff_mantooth_2021, title={ONCO-IMMUNOLOGICAL MECHANISMS OF FOCAL ABLATION AND LOCALIZED IL-12 IMMUNOTHERAPY}, volume={9}, ISSN={["2051-1426"]}, DOI={10.1136/jitc-2021-SITC2021.620}, abstractNote={BackgroundUnresectable solid malignancies are responsible for a major proportion of total cancer-related mortalities, making focal ablation an attractive alternative. Nevertheless, there are high rates of recurrence after ablation [1,2]. The addition of an immune agonist to ablation has the potential to prevent this recurrence and improve treatment outcomes. The goal of this study is to determine if localized interleukin-12 (IL-12) can prevent primary tumor recurrence after cryoablation in both minimal ablation and metastasis models.}, journal={JOURNAL FOR IMMUNOTHERAPY OF CANCER}, author={Vrabel, Maura and Zaharoff, David and Mantooth, Siena}, year={2021}, month={Nov}, pages={A650–A650} }
 @article{nguyen_wagner_vrabel_mantooth_meritet_zaharoff_2021, title={Safety and Pharmacokinetics of Intravesical Chitosan/Interleukin-12 Immunotherapy in Murine Bladders}, volume={7}, ISSN={["2352-3735"]}, DOI={10.3233/BLC-211542}, abstractNote={BACKGROUND: Intravesical administration of interleukin 12 (IL-12) co-formulated with the biopolymer, chitosan (CS/IL-12), has demonstrated remarkable antitumor activity against preclinical models of bladder cancer. However, given historical concerns regarding severe toxicities associated with systemic IL-12 administration in clinical trials, it is important to evaluate the safety of intravesical CS/IL-12 prior to clinical translation. OBJECTIVE: To evaluate the pharmacokinetics as well as the local and systemic toxicities of intravesical CS/IL-12 immunotherapy in laboratory mice. METHODS: Local inflammatory responses in mouse bladders treated with intravesical IL-12 or CS/IL-12 were assessed via histopathology. Serum cytokine levels following intravesical and subcutaneous (s.c.) administrations of IL-12 or CS/IL-12 in laboratory mice were compared. Systemic toxicities were evaluated via body weight and liver enzyme levels. RESULTS: Intravesical IL-12 and CS/IL-12 treatments did not induce significant local or systemic toxicity. IL-12 dissemination and exposure from intravesical administration was significantly lower compared to s.c. injections. Weekly intravesical CS/IL-12 treatments were well-tolerated and did not result in blunted immune responses. CONCLUSIONS: Intravesical CS/IL-12 is safe and well-tolerated in mice. In particular, the lack of cystitis and acute inflammation justifies continued investigation of intravesical CS/IL-12 immunotherapy in larger animals and patients with bladder cancer.}, number={4}, journal={BLADDER CANCER}, author={Nguyen, Khue G. and Wagner, Ethan S. and Vrabel, Maura R. and Mantooth, Siena M. and Meritet, Danielle M. and Zaharoff, David A.}, year={2021}, pages={427–437} }