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Iqbal S, Blenner M, Alexander-Bryant A, Larsen J. Polymersomes for Therapeutic Delivery of Protein and Nucleic Acid Macromolecules: From Design to Therapeutic Applications. Biomacromolecules 2020; 21:1327-1350. [DOI: 10.1021/acs.biomac.9b01754] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Caffery B, Lee JS, Alexander-Bryant AA. Vectors for Glioblastoma Gene Therapy: Viral & Non-Viral Delivery Strategies. NANOMATERIALS (BASEL, SWITZERLAND) 2019; 9:E105. [PMID: 30654536 PMCID: PMC6359729 DOI: 10.3390/nano9010105] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/21/2018] [Accepted: 01/03/2019] [Indexed: 12/14/2022]
Abstract
Glioblastoma multiforme is the most common and aggressive primary brain tumor. Even with aggressive treatment including surgical resection, radiation, and chemotherapy, patient outcomes remain poor, with five-year survival rates at only 10%. Barriers to treatment include inefficient drug delivery across the blood brain barrier and development of drug resistance. Because gliomas occur due to sequential acquisition of genetic alterations, gene therapy represents a promising alternative to overcome limitations of conventional therapy. Gene or nucleic acid carriers must be used to deliver these therapies successfully into tumor tissue and have been extensively studied. Viral vectors have been evaluated in clinical trials for glioblastoma gene therapy but have not achieved FDA approval due to issues with viral delivery, inefficient tumor penetration, and limited efficacy. Non-viral vectors have been explored for delivery of glioma gene therapy and have shown promise as gene vectors for glioma treatment in preclinical studies and a few non-polymeric vectors have entered clinical trials. In this review, delivery systems including viral, non-polymeric, and polymeric vectors that have been used in glioblastoma multiforme (GBM) gene therapy are discussed. Additionally, advances in glioblastoma gene therapy using viral and non-polymeric vectors in clinical trials and emerging polymeric vectors for glioma gene therapy are discussed.
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Review |
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Alexander-Bryant AA, Vanden Berg-Foels WS, Wen X. Bioengineering strategies for designing targeted cancer therapies. Adv Cancer Res 2013; 118:1-59. [PMID: 23768509 DOI: 10.1016/b978-0-12-407173-5.00002-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The goals of bioengineering strategies for targeted cancer therapies are (1) to deliver a high dose of an anticancer drug directly to a cancer tumor, (2) to enhance drug uptake by malignant cells, and (3) to minimize drug uptake by nonmalignant cells. Effective cancer-targeting therapies will require both passive- and active-targeting strategies and a thorough understanding of physiologic barriers to targeted drug delivery. Designing a targeted therapy includes the selection and optimization of a nanoparticle delivery vehicle for passive accumulation in tumors, a targeting moiety for active receptor-mediated uptake, and stimuli-responsive polymers for control of drug release. The future direction of cancer targeting is a combinatorial approach, in which targeting therapies are designed to use multiple-targeting strategies. The combinatorial approach will enable combination therapy for delivery of multiple drugs and dual ligand targeting to improve targeting specificity. Targeted cancer treatments in development and the new combinatorial approaches show promise for improving targeted anticancer drug delivery and improving treatment outcomes.
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Research Support, N.I.H., Extramural |
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Samec T, Boulos J, Gilmore S, Hazelton A, Alexander-Bryant A. Peptide-based delivery of therapeutics in cancer treatment. Mater Today Bio 2022; 14:100248. [PMID: 35434595 PMCID: PMC9010702 DOI: 10.1016/j.mtbio.2022.100248] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 03/14/2022] [Accepted: 03/27/2022] [Indexed: 11/09/2022] Open
Abstract
Current delivery strategies for cancer therapeutics commonly cause significant systemic side effects due to required high doses of therapeutic, inefficient cellular uptake of drug, and poor cell selectivity. Peptide-based delivery systems have shown the ability to alleviate these issues and can significantly enhance therapeutic loading, delivery, and cancer targetability. Peptide systems can be tailor-made for specific cancer applications. This review describes three peptide classes, targeting, cell penetrating, and fusogenic peptides, as stand-alone nanoparticle systems, conjugations to nanoparticle systems, or as the therapeutic modality. Peptide nanoparticle design, characteristics, and applications are discussed as well as peptide applications in the clinical space.
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Alexander-Bryant AA, Zhang H, Attaway CC, Pugh W, Eggart L, Sansevere RM, Andino LM, Dinh L, Cantini LP, Jakymiw A. Dual peptide-mediated targeted delivery of bioactive siRNAs to oral cancer cells in vivo. Oral Oncol 2017; 72:123-131. [PMID: 28797448 DOI: 10.1016/j.oraloncology.2017.07.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/19/2017] [Accepted: 07/04/2017] [Indexed: 01/27/2023]
Abstract
OBJECTIVES Despite significant advances in cancer treatment, the prognosis for oral cancer remains poor in comparison to other cancer types, including breast, skin, and prostate. As a result, more effective therapeutic modalities are needed for the treatment of oral cancer. Consequently, in the present study, we examined the feasibility of using a dual peptide carrier approach, combining an epidermal growth factor receptor (EGFR)-targeting peptide with an endosome-disruptive peptide, to mediate targeted delivery of small interfering RNAs (siRNAs) into EGFR-overexpressing oral cancer cells and induce silencing of the targeted oncogene, cancerous inhibitor of protein phosphatase 2A (CIP2A). MATERIALS AND METHODS Fluorescence microscopy, real-time PCR, Western blot analysis, and in vivo bioimaging of mice containing orthotopic xenograft tumors were used to examine the ability of the dual peptide carrier to mediate specific delivery of bioactive siRNAs into EGFR-overexpressing oral cancer cells/tissues. RESULTS Co-complexation of the EGFR-targeting peptide, GE11R9, with the endosome-disruptive 599 peptide facilitated the specific uptake of siRNAs into oral cancer cells overexpressing EGFR in vitro with optimal gene silencing observed at a 60:30:1 (GE11R9:599:siRNA) molar ratio. Furthermore, when administered systemically to mice bearing xenograft oral tumors, this dual peptide complex mediated increased targeted delivery of siRNAs into tumor tissues in comparison to the 599 peptide alone and significantly enhanced CIP2A silencing. CONCLUSION Herein we provide the first report demonstrating the clinical potential of a dual peptide strategy for siRNA-based therapeutics by synergistically mediating the effective targeting and delivery of bioactive siRNAs into EGFR-overexpressing oral cancer cells.
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Alexander-Bryant AA, Dumitriu A, Attaway CC, Yu H, Jakymiw A. Fusogenic-oligoarginine peptide-mediated silencing of the CIP2A oncogene suppresses oral cancer tumor growth in vivo. J Control Release 2015; 218:72-81. [PMID: 26386438 DOI: 10.1016/j.jconrel.2015.09.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 08/28/2015] [Accepted: 09/14/2015] [Indexed: 11/18/2022]
Abstract
Intracellular delivery and endosomal escape of functional small interfering RNAs (siRNAs) remain major barriers limiting the clinical translation of RNA interference (RNAi)-based therapeutics. Recently, we demonstrated that a cell-penetrating endosome-disruptive peptide we synthesized, termed 599, enhanced the intracellular delivery and bioavailability of siRNAs designed to target the CIP2A oncoprotein (siCIP2A) into oral cancer cells and consequently inhibited oral cancer cell invasiveness and anchorage-independent growth in vitro. Thus, to further assess the therapeutic potential of the 599 peptide in mediating RNAi-based therapeutics for oral cancer and its prospective applicability in clinical settings, the objective of the current study was to determine whether intratumoral dosing of the 599 peptide-siCIP2A complex could induce silencing of CIP2A and consequently impair tumor growth using a xenograft oral cancer mouse model. Our results demonstrate that the 599 peptide is able to protect siRNAs from degradation by serum and ribonucleases in vitro and upon intratumoral injection in vivo, confirming the stability of the 599 peptide-siRNA complex and its potential for therapeutic utility. Moreover, 599 peptide-mediated delivery of siCIP2A to tumor tissue induces CIP2A silencing without any associated toxicity, consequently resulting in reduction of the mitotic index and significant inhibition of tumor growth. Together, these data suggest that the 599 peptide carrier is a clinically effective mediator of RNAi-based cancer therapeutics.
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Pitz ME, Nukovic AM, Elpers MA, Alexander-Bryant AA. Factors Affecting Secondary and Supramolecular Structures of Self-Assembling Peptide Nanocarriers. Macromol Biosci 2021; 22:e2100347. [PMID: 34800001 DOI: 10.1002/mabi.202100347] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/19/2021] [Indexed: 01/12/2023]
Abstract
Self-assembling peptides are a popular vector for therapeutic cargo delivery due to their versatility, tunability, and biocompatibility. Accurately predicting secondary and supramolecular structures of self-assembling peptides is essential for de novo peptide design. However, computational modeling of such assemblies is not yet able to accurately predict structure formation for many peptide sequences. This review identifies patterns in literature between secondary and supramolecular structures, primary sequences, and applications to provide a guide for informed peptide design. An overview of peptide structures, their applications as nanocarriers, and analytical methods for characterizing secondary and supramolecular structure is examined. A top-down approach is then used to identify trends between peptide sequence and assembly structure from the current literature, including an analysis of the drivers at work, such as local and nonlocal sequence effects and solution conditions.
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Miller EM, Samec TM, Alexander-Bryant AA. Nanoparticle delivery systems to combat drug resistance in ovarian cancer. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2020; 31:102309. [PMID: 32992019 DOI: 10.1016/j.nano.2020.102309] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 09/04/2020] [Accepted: 09/17/2020] [Indexed: 12/17/2022]
Abstract
Due to the lack of early symptoms and difficulty of accurate diagnosis, ovarian cancer is the most lethal gynecological cancer faced by women. First-line therapy includes a combination of tumor resection surgery and chemotherapy regimen. However, treatment becomes more complex upon recurrence due to development of drug resistance. Drug resistance has been linked to many mechanisms, including efflux transporters, apoptosis dysregulation, autophagy, cancer stem cells, epigenetics, and the epithelial-mesenchymal transition. Thus, developing and choosing effective therapies is exceptionally complex. There is a need for increased specificity and efficacy in therapies for drug-resistant ovarian cancer, and research in targeted nanoparticle delivery systems aims to fulfill this challenge. Although recent research has focused on targeted nanoparticle-based therapies, few of these therapies have been clinically translated. In this review, non-viral nanoparticle delivery systems developed to overcome drug-resistance in ovarian cancer were analyzed, including their structural components, surface modifications, and drug-resistance targeted mechanisms.
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Research Support, U.S. Gov't, Non-P.H.S. |
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Attia MF, Montaser AS, Arifuzzaman M, Pitz M, Jlassi K, Alexander-Bryant A, Kelly SS, Alexis F, Whitehead DC. In Situ Photopolymerization of Acrylamide Hydrogel to Coat Cellulose Acetate Nanofibers for Drug Delivery System. Polymers (Basel) 2021; 13:1863. [PMID: 34205186 PMCID: PMC8200032 DOI: 10.3390/polym13111863] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 05/31/2021] [Accepted: 05/31/2021] [Indexed: 01/17/2023] Open
Abstract
In this study we developed electrospun cellulose acetate nanofibers (CANFs) that were loaded with a model non-steroidal anti-inflammatory drug (NSAID) (ibuprofen, Ib) and coated with poly(acrylamide) (poly-AAm) hydrogel polymer using two consecutive steps: an electrospinning process followed by photopolymerization of AAm. Coated and non-coated CANF formulations were characterized by several microscopic and spectroscopic techniques to evaluate their physicochemical properties. An analysis of the kinetic release profile of Ib showed noticeable differences due to the presence or absence of the poly-AAm hydrogel polymer. Poly-AAm coating facilitated a constant release rate of drug as opposed to a more conventional burst release. The non-coated CANFs showed low cumulative drug release concentrations (ca. 35 and 83% at 5 and 10% loading, respectively). Conversely, poly-AAm coated CANFs were found to promote the release of drug (ca. 84 and 99.8% at 5 and 10% loading, respectively). Finally, the CANFs were found to be superbly cytocompatible.
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Mbiki S, McClendon J, Alexander-Bryant A, Gilmore J. Classifying changes in LN-18 glial cell morphology: a supervised machine learning approach to analyzing cell microscopy data via FIJI and WEKA. Med Biol Eng Comput 2020; 58:1419-1430. [PMID: 32314170 DOI: 10.1007/s11517-020-02177-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 04/01/2020] [Indexed: 11/29/2022]
Abstract
In cell-based research, the process of visually monitoring cells generates large image datasets that need to be evaluated for quantifiable information in order to track the effectiveness of treatments in vitro. With the traditional, end-point assay-based approach being error-prone, and existing computational approaches being complex, we tested existing machine learning frameworks to find methods that are relatively simple, yet powerful enough to accomplish the goal of analyzing cell microscopy data. This paper details the machine learning pipeline for pixel-based classification and object-based classification. Furthermore, it compares the performances of three classifiers. The classifiers evaluated were the fast-random forest (RF), the sequential minimal optimization (SMO), and the Bayesian network (BN). Images were first preprocessed using smoothing and contrast methods found in FIJI. For pixel-based classification, the preprocessed images were fed into the Trainable Waikato Segmentation (TWS). For object-based classification, training and classification were conducted within the Waikato Environment for Knowledge Analysis (WEKA) interface. All classifiers' performance was evaluated using the WEKA experimental explorer. In terms of performance, the BN had the lowest classification accuracy for both the pixel-based and object-based model. The object-based SMO classifier had the best performance with the lowest mean absolute error of 0.05. The TWS and WEKA interface allows users to easily create and train classifiers for image analysis. However, for analyzing large image datasets, they are not ideal. Grapical abstract.
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Samec T, Alatise KL, Boulos J, Gilmore S, Hazelton A, Coffin C, Alexander-Bryant A. Fusogenic peptide delivery of bioactive siRNAs targeting CSNK2A1 for treatment of ovarian cancer. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 30:95-111. [PMID: 36213692 PMCID: PMC9530961 DOI: 10.1016/j.omtn.2022.09.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
Ovarian cancer has shown little improvement in survival among advanced-stage patients over the past decade. Current treatment strategies have been largely unsuccessful in treating advanced disease, with many patients experiencing systemic toxicity and drug-resistant metastatic cancer. This study evaluates novel fusogenic peptide carriers delivering short interfering RNA (siRNA) targeting casein kinase II, CSNK2A1, for reducing the aggressiveness of ovarian cancer. The peptides were designed to address two significant barriers to siRNA delivery: insufficient cellular uptake and endosomal entrapment. The three peptide variants developed, DIVA3, DIV3H, and DIV3W, were able to form monodisperse nanoparticle complexes with siRNA and protect siRNAs from serum and RNase degradation. Furthermore, DIV3W demonstrated optimal delivery of bioactive siRNAs into ovarian cancer cells with high cellular uptake efficiency and mediated up to 94% knockdown of CSNK2A1 mRNA compared with non-targeting siRNAs, resulting in decreased cell migration and recolonization in vitro. Intratumoral delivery of DIV3W-siCSNK2A1 complexes to subcutaneous ovarian tumors resulted in reduced CSNK2A1 mRNA and CK2α protein expression after 48 h and reduced tumor growth and migration in a 2-week multi-dosing regimen. These results demonstrate the potential of the DIV3W peptide to deliver bioactive siRNAs and confirms the role of CSNK2A1 in cell-cell communication and proliferation in ovarian cancer.
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Gardner S, Alatise KL, Miller E, Grant E, Alexander-Bryant A. Abstract 306: Cationic cholesterol liposomes for combination therapy to treat drug-resistant ovarian cancer. Cancer Res 2021. [DOI: 10.1158/1538-7445.am2021-306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction: Ovarian cancer is the fifth leading cause of cancer mortality in women, with nearly 75% of women who respond to initial platinum-based chemotherapy experiencing relapse due to drug resistance [1,2]. Liposomes are a promising solution to overcoming drug resistance due to their biocompatibility and capacity to encapsulate hydrophilic and hydrophobic drugs as well as complex small interfering RNA (siRNA), which have the potential to downregulate the expression of genes related to drug resistance [3]. We aim to synthesize and characterize a cationic liposomal system to deliver siRNA and paclitaxel (PTX) to ovarian cancer cells.
Methods: Cholesterol (CHOL) liposomes were synthesized by the thin-film hydration method. Dynamic light scattering (DLS) was used to determine the size, polydispersity index (PDI), and zeta potential of the liposomes. Uptake of liposomes into OVCAR3 and OVCAR3-T40, a wild-type and a paclitaxel-resistant human adenocarcinoma cell line, was examined using fluorescence microscopy. The cytotoxicity of unloaded CHOL liposomes was evaluated through MTS assay on OVCAR3 and OVCAR3-T40 cells.
Results: PTX- and siRNA-loaded CHOL liposomes had an average diameter of 114.9 ± 10.35 nm and a zeta potential of 27.6 ± 1.79 mV. Blank CHOL liposomes had an average diameter of 123.0 ± 2.49 nm and zeta potential of 32.3 ± 2.16 mV. All formulations of liposomes were cationic and formed monodisperse nanoparticles. The encapsulation efficiency of siRNA and PTX was 99.8% and 80.4% respectively. Coumarin 6, a hydrophobic model drug, was loaded into liposomes to verify cellular uptake through fluorescent imaging. Results demonstrated that the liposomal system was efficiently delivered intracellularly. Blank liposomes were used to determine the toxicity of the delivery system. The unloaded liposomes were not cytotoxic to both the wild-type and drug-resistant cell lines at concentrations up to 75 µg/mL, and therefore, cytotoxicity of drug-loaded liposomes can be attributed to paclitaxel, siRNA, or combination treatment.
Conclusions: Liposomes were successfully formed with a monodisperse size, exhibited effective drug and siRNA loading, and were internalized into OVCAR3 and OVCAR3-T40 cells. Future work includes investigating the efficacy of the liposomal system in mediating gene silencing.
Acknowledgements: This work was supported in part by the National Science Foundation EPSCoR Program under NSF Award # OIA-1655740 and Clemson Creative Inquiry.
References: [1] Torre, L. A., CA Cancer J Clin. 2018;68(4):284-296, [2], Norouzi-Barough L., J Cell Physiol.2018;233(6):4546-4562, [3] Farra R., Pharmaceutics. 2019;11(10):547.
Citation Format: Samantha Gardner, Kharimat L. Alatise, Emily Miller, Emily Grant, Angela Alexander-Bryant. Cationic cholesterol liposomes for combination therapy to treat drug-resistant ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 306.
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Alatise KL, Gardner S, Alexander-Bryant A. Abstract 281: pH-sensitive liposome for siRNA delivery to treat drug-resistant ovarian cancer. Cancer Res 2021. [DOI: 10.1158/1538-7445.am2021-281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction: With a 5-year survival rate of 47%, ovarian cancer is the 5th leading cause of death amongst women worldwide. Over 75% of patients experience recurrence after initial treatment, indicating a need for improved treatment options. Drug resistance is a major barrier hindering the success of current treatment methods. Our study analyzes the characteristics of a stimuli-sensitive liposomal delivery system for combatting drug resistance. Our delivery system will deliver bioactive siRNAs targeting genes related to drug resistance, cell proliferation, and apoptosis. In this study, we investigate the characteristics of the liposomes to determine particle size, surface charge, and ability to encapsulate/bind both siRNAs. We also begin to investigate the delivery potential of the pH-sensitive liposomal formulation in vitro using ovarian cancer cell lines.
Methods: Empty and siRNA loaded cationic, pH-sensitive liposomes (CHEMS-LPs) were synthesized by the thin-film hydration method. Liposome size, zeta potential, and polydispersity index (PDI) were measured by dynamic light scattering (DLS). To measure siRNA encapsulation efficiency, fluorescently labeled siRNA was loaded into CHEMS-LPs and subjected to centrifugation to pellet the LPs. Fluorescence spectroscopy was used to detect siRNA in the supernatant. The toxicity of unloaded CHEMS-LPs was determined by an MTS assay using OVCAR3 (drug-sensitive) and OVCAR3-T40 (drug-resistant) human ovarian cancer cells.
Results: The size and zeta potential of blank and siRNA-loaded CHEMS-LPs were 97.88 ± 2.39 nm and 29.0 ± 2.00 mV, and 80.78 ± 0.77 nm and 13.1 ±1.66 mV, respectively. The positively charged zeta potential confirms the cationic nature of our liposomes. The PDI demonstrated that the liposomes were unimodal and monodisperse with PDI values of less than 0.300 for each formulation. In addition, siRNA was successfully bound to CHEMS-LPs through electrostatic interaction with the cationic lipid layer, resulting in an encapsulation efficiency of 99.6%
Conclusion: CHEMS-LPs are pH-sensitive, cationic, monodisperse liposomes able to encapsulate siRNAs in order to mediate delivery into ovarian cancer cells. Their stable structure, positive charge, and low cytotoxicity is promising for future studies, including delivery of bioactive siRNAs to stimulate downregulation of target genes related to drug resistance.
Acknowledgements: This work was supported in part by the National Science Foundation EPSCoR Program under Award # OIA-1655740. We would like to thank George Duran from Stanford University for donating the OVCAR3-T40 cell line.
Citation Format: Kharimat Lora Alatise, Samantha Gardner, Angela Alexander-Bryant. pH-sensitive liposome for siRNA delivery to treat drug-resistant ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 281.
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Alexander-Bryant A, Dumitriu A, Attaway C, Yu H, Jakymiw A. Abstract LB-106: Fusogenic-oligoarginine peptide-mediated silencing of the CIP2A oncogene suppresses oral cancer tumor growth in vivo. Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-lb-106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Intracellular delivery and endosomal escape of functional small interfering RNAs (siRNAs) remain major barriers limiting the clinical translation of RNA interference (RNAi)-based therapeutics. Recently, we demonstrated that a endosome-disruptive peptide we synthesized termed, 599, could enhance the intracellular delivery and bioavailability of siRNAs designed to target the CIP2A oncoprotein (siCIP2A) into oral cancer cells and consequently inhibit oral cancer cell invasiveness and anchorage-independent growth in vitro. Thus, to further assess the therapeutic potential of the 599 peptide in mediating RNAi-based therapeutics for oral cancer and its prospective applicability in clinical settings, the objective of the current study was to determine whether intratumoral dosing of the 599+siCIP2A complex could induce silencing of CIP2A and consequently impair tumor growth using a xenograft oral cancer mouse model. Our results demonstrated that the 599 peptide was able to protect siRNAs from degradation by serum and ribonucleases in vitro, confirming the stability of the 599+siRNA complex and its potential for in vivo utility. Moreover, 599 peptide-mediated delivery of siCIP2A to tumor tissue induced CIP2A silencing without any associated toxicity, consequently resulting in reduction of the mitotic index and significant inhibition of tumor growth. Together, these data suggest that the 599 peptide carrier could be a clinically effective mediator of RNAi-based cancer therapeutics.
Citation Format: Angela Alexander-Bryant, Anca Dumitriu, Christopher Attaway, Hong Yu, Andrew Jakymiw. Fusogenic-oligoarginine peptide-mediated silencing of the CIP2A oncogene suppresses oral cancer tumor growth in vivo. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr LB-106. doi:10.1158/1538-7445.AM2015-LB-106
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Boulos J, Alexander-Bryant A. Abstract 1310: Peptide delivery of siRNA in GBM. Cancer Res 2021. [DOI: 10.1158/1538-7445.am2021-1310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Glioblastoma Multiforme (GBM), a grade VI glioma, is an aggressive malignant tumorwith a poor prognosis. With an incidence rate of 3.19 per 100,000, GBM has a median survivalrate of 12-15 months and a five-year survival rate of less than 5%. Typical treatments involvesurgical removal, chemotherapy, and radiation; however, these treatments still result in a lowsurvival rate and can lead to potential harm to healthy cells. Therefore, a new therapeutic isneeded for GBM treatment to improve patient outcomes. RNAi, a naturally found process,utilizes siRNA to target specific mRNA for degradation to inhibit protein translation and hasshown clinical potential for targeting and silencing oncogenes. However, barriers to siRNAdelivery, such as cellular uptake, non-specificity, and lack of endosomal escape hinder clinicaltranslation of RNAi therapeutics. Peptides are a promising carrier for siRNAs and havedemonstrated the potential to overcome barriers to delivery. The purpose of this study is todesign a novel tandem peptide for siRNA delivery, evaluate ability to mediate knockdown of atarget oncogene, and compare the efficacy of the tandem peptide to the individual peptidesalone. The tandem peptide is a novel combination of a fusogenic peptide and a targetingpeptide. STAT3, the target gene, is an oncogene that plays a role in cell proliferation,differentiation, apoptosis, and angiogenesis in GBM. Initial results have confirmed basal expression of EGFR and STAT3 in all three GBM cell lines, LN18, U118, and T98G.Characterization of the fusogenic, targeting, and tandem peptides indicated formation of monodispere nanoparticles with diameters less than 150 nm when complexed with siRNA. Furthermore, gel shift assays were conducted and confirmed that the tandem peptide protectedthe siRNA from degradation in 50% FBS. MTS assays conducted in all three cell lines for eachpeptide confirmed that there was no significant cytotoxicity due to the vehicles alone. Finally, flow cytometry confirmed uptake of the tandem peptide in T98G cell line. Therefore, it ishypothesized that the tandem peptide composed of both fusogenic targeting peptide willenhance cell-specific uptake of STAT3 siRNA into glioblastoma cells for mediating endosomalescape, resulting in more effective gene silencing and associated downstream effects comparedto the fusogenic and targeting peptides alone. Future studies include immunofluorescence for uptake and endosomal escape, knockdown studies (MTS, Western Blot, and qPCR assays), and assays to examine the downstream effect of silencing STAT3, such as migration and invasion assays.
Citation Format: Jessica Boulos, Angela Alexander-Bryant. Peptide delivery of siRNA in GBM [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1310.
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Attia MF, Ogunnaike EA, Pitz M, Elbaz NM, Panda DK, Alexander-Bryant A, Saha S, Whitehead DC, Kabanov A. Enhancing Drug Delivery with Supramolecular Amphiphilic Macrocycle Nanoparticles: Selective Targeting of CDK4/6 Inhibitor Palbociclib to Melanoma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.21.567974. [PMID: 38045274 PMCID: PMC10690174 DOI: 10.1101/2023.11.21.567974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Drug delivery systems based on amphiphilic supramolecular macrocycles have garnered increased attention over the past two decades due to their ability to successfully formulate nanoparticles. Macrocyclic (MC) materials can self-assemble at lower concentrations without the need for surfactants and polymers, but surfactants are required to form and stabilize nanoparticles at higher concentrations. Using MCs to deliver both hydrophilic and hydrophobic guest molecules is advantageous. We developed two novel types of amphiphilic macrocycle nanoparticles (MC NPs) capable of delivering either Nile Red (NR) (a hydrophobic model) or Rhodamine B (RhB) (a hydrophilic model) fluorescent dyes. We extensively characterized the materials using various techniques to determine size, morphology, stability, hemolysis, fluorescence, loading efficiency (LE), and loading capacity (LC). We then loaded the CDK4/6 inhibitor Palbociclib (Palb) into both MC NPs using a solvent diffusion method. This yielded Palb-MC NPs in the size range of 65-90 nm. They exhibited high stability over time and in fetal bovine serum with negligible toxicity against erythrocytes. Cytotoxicity was minimal when tested against RAW macrophages, human fibroblast HDFn , and adipose stromal cells (ASCs) at higher concentrations of MC NPs. Cell viability studies were conducted with different concentrations of MC NPs, Palb-MC NPs, and free Palb against RAW macrophages, human U-87 GBM, and human M14 melanoma cell lines in vitro. Flow cytometry experiments revealed that blank MC NPs and Palb-MC NPs were selectively targeted to melanoma cells, resulting in cell death compared to the other two cell lines. Future work will focus on studying the biological effect of MC NPs including their binding affinity with molecules/receptors expressed on the M14 and other melanoma cell surface by molecular docking simulations. Subsequently, we will evaluate the MCs as a component of combination therapy in a murine melanoma model. Graphical abstract
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Alexander-Bryant AA, Hourigan B, Lynn M, Lee JS. Abstract 3098: Nanotherapeutics for combination drug and gene therapy in treating glioblastoma multiforme. Cancer Res 2017. [DOI: 10.1158/1538-7445.am2017-3098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Gliomas represent approximately 80% of all malignant brain tumors, and glioblastoma multiforme (GBM), the most aggressive type, accounts for nearly half of all gliomas. Despite treatment strategies including surgery, radiation, and chemotherapy, the 5-year survival rate for brain cancer is only 35%. New therapeutic strategies are necessary to improve the outcomes of this disease. Chemotherapy with DNA alkylating agents is commonly used in treatment for GBM. Research has shown that better therapeutic response of GBM tumors to alkylating agents and increased survival rate is indicative in patients with epigenetic silencing of O6-methylguanine-DNA methyltransferase (MGMT), a gene responsible for DNA repair. Therefore, we propose a treatment strategy combining drug and gene therapy to target and silence MGMT to sensitize cells to treatment with temozolomide (TMZ) or lomustine (CCNU), both DNA alkylating agents. We previously developed cationic, amphiphilic copolymer poly(lactide-co-glycolide)-g-polyethylenimine (PgP) and demonstrated its utility for nucleic acid delivery. Here, we examine the ability of PgP as a drug and siRNA delivery carrier to overcome drug resistance and improve anticancer activity through combination drug and gene therapy for GBM treatment. PgP micelles were designed and synthesized for delivery of hydrophobic drugs in the PLGA core and negatively charged nucleic acids in the positively charged PEI shell through electrostatic interactions. RNA binding and polyplex stability assays were performed using agarose gel electrophoresis. Cytotoxicity of TMZ, CCNU, and/or PgP/siMGMT polyplexes was determined by MTT assay. Silencing of MGMT on the protein and mRNA level was determined using western blotting and qPCR, respectively. Our results demonstrated that PgP effectively forms stable complexes with siRNA and protects siRNAs from serum- and ribonuclease-mediated degradation, confirming the potential of the polyplex for in vivo delivery. We demonstrated that PgP/siMGMT polyplexes mediate knockdown of MGMT protein as well as a significant ~56% and ~68% knockdown of MGMT mRNA in T98G GBM cells compared to cells treated with PgP complexed with non-targeting siRNA (siNT) at a 60:1 and 80:1 nitrogen:phosphate (N:P) ratio, respectively. Further, co-treatment of PgP/siMGMT polyplexes with TMZ or CCNU enhanced anticancer activity in T98G GBM cells compared to treatment with the PgP/siMGMT polyplex, TMZ, or CCNU alone. Future studies will determine efficacy of drug-loaded and siRNA-complexed PgP for combination therapy in vitro as well as using a xenograft GBM model for local delivery. Successful combinatorial drug and gene therapy using PgP may overcome drug resistance and improve therapeutic outcomes for patients with glioblastoma.
Citation Format: Angela A. Alexander-Bryant, Breanne Hourigan, Michael Lynn, Jeoung Soo Lee. Nanotherapeutics for combination drug and gene therapy in treating glioblastoma multiforme [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3098. doi:10.1158/1538-7445.AM2017-3098
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Hazelton A, Samec T, Boulos J, Gilmore S, Alexander-Bryant A. Abstract 304: Peptide-mediated delivery of siRNAs targeting CSNK2A1 decreases migration of ovarian cancer cells in vitro. Cancer Res 2021. [DOI: 10.1158/1538-7445.am2021-304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background Ovarian cancer (OC) is among the most commonly diagnosed cancers and combined with the low responses to therapeutics, it has the highest mortality among gynecological cancers. When diagnosed at stage III and stage IV, survival rates remain below 30%. Over 90% of ovarian cancers are epithelial-based, resulting in proliferation with both local and distant metastasis. Common modes of treatment typically include surgical debulking and platinum-based chemotherapies. However, approximately 80% of confirmed late-stage OC patients will encounter recurrence, multidrug resistance, or metastasis. As a result, there is a need for more effective treatments by means of sustainable therapeutics. RNA interference (RNAi)- based therapies via short interfering RNA (siRNA) have shown promise a potential treatment method. However, siRNAs cannot readily enter the cell due to their large size and negative charge. Thus, siRNAs must be combined with a carrier that maintains the efficacy of the therapeutic by promoting membrane interaction, internalization, and release of siRNAs. Fusogenic peptides (FPs) serve as efficient carriers by complexing with siRNAs through electrostatic interactions and mediating endosomal escape to maintain bioactivity. Here, we investigate the use of a novel FP for the delivery of siRNAS targeting CSNK2A1 and characterize ovarian cancer cell response.
Methods OVCAR3 human ovarian cancer cells were treated with fusogenic peptides complexed with either non-targeting siRNAs or siRNAs targeting CSNK2A1 at varying nitrogen to phosphorus (N:P) ratios and downstream cellular analysis was conducted. Cytotoxicity of both the fusogenic peptide vehicle alone and peptide/siRNA complexes was determined using MTS assays. The effect of the peptide/siRNA complex on ovarian cancer cell migration was measured using a scratch wound healing assays.
Results The FP vehicle displayed no significant decreases in cell viability at higher N:P ratios. This result indicates that the FP vehicle is not cytotoxic to the cells and demonstrate the potential biocompatibility of the delivery system. In the scratch wound healing assay, percent wound healing was substantially decreased when ovarian cancer cells were treated with peptide complexed with siRNAs targeting CSNK2A1 in contrast to treatment with peptide complexed with non-targeting siRNAs. Higher N:P ratios displayed an overall greater decrease in wound healing. In future studies, we will examine whether peptide/siRNA complexes affect the invasiveness of ovarian cancer cells.
Citation Format: Anthony Hazelton, Timothy Samec, Jessica Boulos, Serena Gilmore, Angela Alexander-Bryant. Peptide-mediated delivery of siRNAs targeting CSNK2A1 decreases migration of ovarian cancer cells in vitro [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 304.
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Eckert T, Zobaer MS, Boulos J, Alexander-Bryant A, Baker TG, Rivers C, Das A, Vandergrift WA, Martinez J, Zukas A, Lindhorst SM, Patel S, Strickland B, Rowland NC. Immune Resistance in Glioblastoma: Understanding the Barriers to ICI and CAR-T Cell Therapy. Cancers (Basel) 2025; 17:462. [PMID: 39941829 PMCID: PMC11816167 DOI: 10.3390/cancers17030462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2024] [Revised: 01/21/2025] [Accepted: 01/26/2025] [Indexed: 02/16/2025] Open
Abstract
BACKGROUND Glioblastoma (GBM) is the most common primary malignant brain tumor, with fewer than 5% of patients surviving five years after diagnosis. The introduction of immune checkpoint inhibitors (ICIs), followed by chimeric antigen receptor (CAR) T-cell therapy, marked major advancements in oncology. Despite demonstrating efficacy in other blood and solid cancers, these therapies have yielded limited success in clinical trials for both newly diagnosed and recurrent GBM. A deeper understanding of GBM's resistance to immunotherapy is essential for enhancing treatment responses and translating results seen in other cancer models. OBJECTIVES In this review, we examine clinical trial outcomes involving ICIs and CAR-T for GBM patients and explore the evasive mechanisms of GBM and the tumor microenvironment. FINDINGS AND DISCUSSION Multiple clinical trials investigating ICIs in GBM have shown poor outcomes, with no significant improvement in progression-free survival (PFS) or overall survival (OS). Results from smaller case studies with CAR-T therapy have warranted further investigation. However, no large-scale trials or robust studies have yet established these immunotherapeutic approaches as definitive treatment strategies. Future research should shift focus from addressing the scarcity of functional T cells to exploiting the abundant myeloid-derived cells within the tumor microenvironment. CONCLUSIONS Translating these therapies into effective treatments for glioblastoma in humans remains a significant challenge. The highly immunosuppressive nature of GBM and its tumor microenvironment continue to hinder the success of these innovative immunotherapeutic approaches. Targeting the myeloid-derived compartment may lead to more robust and sustained immune responses.
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Pitz M, Nukovic A, Elpers M, Wilde S, Alexander-Bryant A. Abstract 299: Self-assembling peptide hydrogel for delivery and conversion of temozolomide in glioblastoma treatment. Cancer Res 2021. [DOI: 10.1158/1538-7445.am2021-299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Traditional treatment methods for glioblastoma multiforme (GBM) including resection, radiation, and chemotherapy have been largely unsuccessful, with a current 5-year survival rate of 5.6%. In this project we examine the potential of nanosized self-assembling peptide hydrogels to locally deliver and convert temozolomide (TMZ), an FDA-approved pH-sensitive prodrug, for GBM treatment. The peptide hydrogel is designed to load TMZ into the hydrophobic regions of the hydrogels, and during hydrogel degradation in vivo, convert TMZ into its active form. Hydrogel characterization, drug loading and conversion, and cellular uptake and viability are examined to determine the in vitro efficacy of this delivery method. A combination of dynamic light scattering (DLS), scanning electron microscopy (SEM), and circular dichroism (CD) are used to characterize size and structure of the hydrogels. Loading and conversion of TMZ are quantified using UV-Vis spectroscopy. Fluorescent imaging and cell viability assays are used to determine uptake and anti-cancer effects of the drug-loaded hydrogels on glioblastoma cells. Our results show high uptake in drug-resistant T98G and non-resistant LN-18 glioblastoma cell lines using several of our tunable peptide formulations. CD has shown that all peptide formulations form mostly beta-sheet and random structures during self-assembly. SEM and DLS show that peptide hydrogels formed in a water solvent are more polydisperse than hydrogels in a PBS solvent. Using a pH-meter, we have shown that as the peptides in PBS degrade, there is an increase in local pH. Additionally, TMZ conversion is observed to occur more quickly in drug-loaded hydrogels than TMZ alone. Preliminary cell viability studies have shown that unassembled peptides are not cytotoxic; some of the assembled peptide hydrogels are cytotoxic while others maintain greater than 80% viability when compared to untreated cells. Future studies for the project will include cell viability assays with the most promising peptide formulations loaded with TMZ to determine efficacy of the delivery and conversion system. Finally, this project will culminate in an in vivo study to confirm the overall anti-cancer effect of the drug-loaded peptide hydrogels in a tumor model of GBM. Acknowledgements: This research was supported in part by the National Science Foundation EPSCoR Program under NSF Award # OIA-1655740, the National Institute of Health Award # P30GM131959, and National Science Foundation's Graduate Research Fellowship Program.
Citation Format: Megan Pitz, Alexandra Nukovic, Margaret Elpers, Sarah Wilde, Angela Alexander-Bryant. Self-assembling peptide hydrogel for delivery and conversion of temozolomide in glioblastoma treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 299.
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Attia MF, Ogunnaike EA, Pitz M, Elbaz NM, Panda DK, Alexander-Bryant A, Saha S, Whitehead DC, Kabanov A. Enhancing drug delivery with supramolecular amphiphilic macrocycle nanoparticles: selective targeting of CDK4/6 inhibitor palbociclib to melanoma. Biomater Sci 2024; 12:725-737. [PMID: 38099834 PMCID: PMC10872447 DOI: 10.1039/d3bm01888a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2023]
Abstract
Drug delivery systems based on amphiphilic supramolecular macrocycles have garnered increased attention over the past two decades due to their ability to successfully formulate nanoparticles. Macrocyclic (MC) materials can self-assemble at lower concentrations without the need for surfactants and polymers, but surfactants are required to form and stabilize nanoparticles at higher concentrations. Using MCs to deliver both hydrophilic and hydrophobic guest molecules is advantageous. We developed two novel types of amphiphilic macrocycle nanoparticles (MC NPs) capable of delivering either Nile Red (NR) (a hydrophobic model) or Rhodamine B (RhB) (a hydrophilic model) fluorescent dyes. We extensively characterized the materials using various techniques to determine size, morphology, stability, hemolysis, fluorescence, loading efficiency (LE), and loading capacity (LC). We then loaded the CDK4/6 inhibitor Palbociclib (Palb) into both MC NPs using a solvent diffusion method. This yielded Palb-MC NPs in the size range of 65-90 nm. They exhibited high stability over time and in fetal bovine serum with negligible toxicity against erythrocytes. Cytotoxicity was minimal when tested against RAW macrophages, human fibroblast HDFn, and adipose stromal cells (ASCs) at higher concentrations of MC NPs. Cell viability studies were conducted with different concentrations of MC NPs, Palb-MC NPs, and free Palb against RAW macrophages, human U-87 GBM, and human M14 melanoma cell lines in vitro. Flow cytometry experiments revealed that blank MC NPs and Palb-MC NPs were selectively targeted to melanoma cells, resulting in cell death compared to the other two cell lines. Future work will focus on studying the biological effect of MC NPs including their binding affinity with molecules/receptors expressed on the M14 and other melanoma cell surfaces by molecular docking simulations. Subsequently, we will evaluate the MCs as a component of combination therapy in a murine melanoma model.
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Samec T, Boulos J, Gilmore S, Alexander-Bryant A. Abstract 2868: A novel fusogenic peptide for delivery of bioactive siRNAs targeting CSNK2A1 in ovarian cancer cells in vitro. Cancer Res 2020. [DOI: 10.1158/1538-7445.am2020-2868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Introduction: Ovarian cancer recurrence and survival rates have remained stagnant over time with current therapeutics displaying low efficacy and often rendered ineffective by degradation. This work presents novel fusogenic peptides that will electrostatically complex with siRNAs and cause a pH-responsive insertion into the endosomal membrane, resulting in destabilization and breakdown allowing for release of siRNAs into the cytoplasm of ovarian cancer cells. Delivery of bioactive siRNAs targeting the CSNK2A1 gene in ovarian cancer cells is hypothesized to reduce cell viability, migration, and invasion.
Experimental Procedures: Peptide formulations were complexed with non-targeting siRNAs (siNT) and CSNK2A1 siRNAs (siCSNK2A1) at various N:P ratios for all procedures. Analysis of complex formation was completed through gel-shift assays and dynamic light scattering. After characterization of the complexes, each formulation without siRNA was delivered to OVCAR-3 and CAOV-3 cells for cytotoxicity analysis measured via MTS assay. Observation of cellular uptake and endosomal escape was completed through fluorescent imaging after delivering each peptide formulation complexed with Cy3-labeled siNT (Cy3-siNT) and performing early endosome antigen-1 staining. To confirm bioactivity of targeted siRNAs, complexes with siCSNK2A1 were delivered and gene silencing was analyzed via western blotting.
Results: Complexation of siRNAs with each formulation was achieved at N:P ratios of 40:1 and greater. Each of the three peptide formulations were able to form uniform nanocomplexes, at 195 nm, 111 nm, and 59 nm with 8.25 mV, -14.56 mV, and -18.42 mV surface charges respectively, and did not display vehicle cytotoxicity at an 80:1 ratio. Each peptide also mediated siRNA uptake into ovarian cancer cells, with fluorescent siRNA signal increasing with increasing N:P ratios. Of note, we observed that Cy3-siRNA appeared separate from the endosome, indicative of endosomal escape, which was seen in several peptide formulations with both CAOV-3 and OVCAR-3 cell lines. Confirmation of bioactive delivery of siCSNK2A1 is shown through western blot imaging, demonstrating knockdown of CSNK2A1 in comparison to cells treated with siNT alone or left untreated.
Conclusion: Our novel fusogenic peptides have shown the ability to complex with and deliver siRNAs into ovarian cancer cells. Each peptide mediates endosomal escape activity, with varying degrees of effectiveness, and silencing of CSNK2A1 as measured by western blot. Further study into downstream effects of CSNK2A1 is ongoing. Future work includes optimization of a single fusogenic sequence for optimal delivery of siRNAs and development of a novel targeting peptide to increase cancer targeting and uptake efficiency.
Acknowledgements: This research was supported in part by the National Science Foundation EPSCoR Program under NSF Award # OIA-1655740.
Citation Format: Timothy Samec, Jessica Boulos, Serena Gilmore, Angela Alexander-Bryant. A novel fusogenic peptide for delivery of bioactive siRNAs targeting CSNK2A1 in ovarian cancer cells in vitro [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2868.
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Pitz M, Elpers M, Nukovic A, Wilde S, Gregory AJ, Alexander-Bryant A. De Novo Self-Assembling Peptides Mediate the Conversion of Temozolomide and Delivery of a Model Drug into Glioblastoma Multiforme Cells. Biomedicines 2022; 10:biomedicines10092164. [PMID: 36140265 PMCID: PMC9495814 DOI: 10.3390/biomedicines10092164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/11/2022] [Accepted: 08/22/2022] [Indexed: 11/16/2022] Open
Abstract
Glioblastoma multiforme (GBM) is the most aggressive central nervous system tumor, and standard treatment, including surgical resection, radiation, and chemotherapy, has not significantly improved patient outcomes over the last 20 years. Temozolomide (TMZ), the prodrug most commonly used to treat GBM, must pass the blood–brain barrier and requires a basic pH to convert to its active form. Due to these barriers, less than 30% of orally delivered TMZ reaches the central nervous system and becomes bioactive. In this work, we have developed a novel biomaterial delivery system to convert TMZ to its active form and that shows promise for intracellular TMZ delivery. Self-assembling peptides were characterized under several different assembly conditions and evaluated for TMZ loading and conversion. Both solvent and method of assembly were found to affect the supramolecular and secondary structure of peptide assemblies. Additionally, as peptides degraded in phosphate-buffered saline, TMZ was rapidly converted to its active form. This work demonstrates that peptide-based drug delivery systems can effectively create a local stimulus during drug delivery while remaining biocompatible. This principle could be used in many future biomedical applications in addition to cancer treatment, such as wound healing and regenerative medicine.
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