422 research outputs found

    Cisplatin Tumor Biodistribution and Efficacy after Intratumoral Injection of a Biodegradable Extended Release Implant

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    Local delivery of chemotherapeutic drugs has long been recognized as a potential method for reaching high drug doses at the target site while minimizing systemic exposure. Cisplatin is one of the most effective chemotherapeutic agents for the treatment of various tumors; however, its systemic toxicity remains the primary dose-limiting factor. Here we report that incorporation of cisplatin into a fatty acid-based polymer carrier followed by a local injection into the solid tumor resulted in a successful tumor growth inhibition in heterotopic mouse bladder tumor model in mice. Platinum concentration in the tumor tissue surrounding the injected implant remained above the therapeutic level up to 14 days after the injection, while the plasma levels were several orders of magnitude lower comparing to systemic delivery. The reported delivery system increased the maximum tolerated dose of cisplatin 5 times compared to systemic delivery, thus potentially improving antitumor efficacy of cisplatin in solid tumor model

    Follicle development as an orchestrated signaling network in a 3D organoid

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    Abstract The ovarian follicle is the structural and functional unit of the ovary, composed of the female gamete (the oocyte) and supportive somatic cells. Follicles are not only the source of a female’s germ cell supply, but also secrete important hormones necessary for proper endocrine function. Folliculogenesis, the growth and maturation of the follicular unit, is a complex process governed by both intrafollicular crosstalk and pituitary-secreted hormones. While the later stages of this process are gonadotropin-dependent, early folliculogenesis appears to be controlled by the ovarian microenvironment and intrafollicular paracrine and autocrine signaling. In vitro follicle culture remains challenging because of the limited knowledge of growth factors and other cytokines influencing early follicle growth. Here we discuss the current state of knowledge on paracrine and autocrine signaling influencing primary follicles as they develop into the antral stage. Given the importance of intrafollicular signaling and the ovarian microenvironment, we reviewed the current engineering approaches for in vitro follicle culture, including 3D systems using natural hydrogels such as alginate and synthetic hydrogels such as poly(ethylene glycol). Our discussion is focused on what drives the proliferation of granulosa cells, development of the thecal layer, and antrum formation—three processes integral to follicle growth up to the antral stage. Further research in this area may reveal the mechanisms behind these complex signaling relationships within the follicle, leading to more successful and physiologically-relevant in vitro culture methods that will translate well to clinical applications.https://deepblue.lib.umich.edu/bitstream/2027.42/146779/1/13036_2018_Article_134.pd

    The Light Nuclei Stopping in a Solid

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    The report discusses processes of light nuclei stopping in a solid-state barrier. Accounting algorithm of energy losses of light nuclei for (0 ÷ 20) MeV – range was considered. Calculated functions of the energy losses for various materials were presented

    Adipose-derived stem cells promote survival, growth, and maturation of early-stage murine follicles

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    Abstract Background Premature ovarian insufficiency is a common complication of anticancer treatments in young women and girls. The ovary is a complex, highly regulated reproductive organ, whose proper function is contingent upon the bidirectional endocrine, paracrine, and autocrine signaling. These factors facilitate the development of the follicles, the functional units of the ovary, to progress from the gonadotropin-independent, paracrine-controlled early stage to the gonadotropin-dependent, endocrine-controlled later stage. We hypothesized that the low survival rate of individually cultured early-stage follicles could be improved with co-culture of adipose-derived stem cells (ADSCs) that secrete survival- and growth-promoting factors. Materials and methods Ovarian follicles ranging from 85 to 115 μm in diameter, from 10- to 12-day-old B6CBAF1 mice were mechanically isolated and co-encapsulated with ADSCs within alginate-based 3D culture system. The follicles were cultured for 14 days, imaged using light microscopy every 2 days, and matured at the end. Follicle media were changed every 2 days and collected for hormone measurements. Follicle diameter, morphology, number of transzonal projections, and survival and maturation rates were recorded. Statistical analyses using one- and two-way ANOVA were performed to compare hormone levels, survival of the follicles and ADSCs, oocyte maturation rates, and follicle growth. Results The co-encapsulation of the follicles with ADSCs increased follicle survival, ranging from 42.4% for the 86–95 μm to 86.2% for the 106–115-μm follicle size group. Co-culture also improved the follicle growth, the rate of antrum formation and oocyte maturation compared to the follicles cultured alone. The levels of androstenedione, estradiol, and progesterone of co-encapsulated follicles increased progressively with time in culture. Conclusions To our knowledge, this is the first report of an in vitro system utilizing mouse adipose-derived stem cells to support the development of the mouse follicles. Our findings suggest that co-encapsulation of ADSCs with early-stage follicles supports follicular development, through secretion of cytokines that promote follicular survival, antrum formation, and meiotic competence. The unique 3D culture system that supports the survival of both cell types has translational implications, as ADSCs could be used as an autologous source for in vitro maturation of early-stage human follicles.https://deepblue.lib.umich.edu/bitstream/2027.42/148317/1/13287_2019_Article_1199.pd

    Fibrin-Mediated Delivery of an Ovarian Follicle Pool in a Mouse Model of Infertility

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    The cryopreservation and autotransplantation of ovarian tissue is emerging as a powerful approach for preserving fertility. However, for cancer patients, it may not be possible to transplant ovarian tissue due to the risk of re-seeding disease. We investigated strategies for transplantation of individually isolated follicles to minimize the risk of re-introducing cancer cells present within the vasculature of ovarian stroma. Procedures for large-scale isolation of early-stage follicles and their encapsulation into fibrin hydrogels were developed. For in vivo validation studies, mice were ovariectomized and transplanted with encapsulated follicles into the ovarian bursa. A substantial increase in the number of secondary follicles was observed in the graft at 9 days after transplantation, and antral follicles by day 21, demonstrating primordial follicle recruitment into the growing pool. Initially, elevated follicle-stimulating hormone levels declined substantially by day 21, indicating feedback from the graft; presence of corpora lutea showed the graft's capability of restoring hormone cyclicity. Taken together, the transplanted follicles were able to engraft, mature, and restore ovarian function in an infertile mouse. This biomaterial may, thus, provide a platform for follicle transplantation with a low risk of cancer contamination and for developing strategies that preserve fertility for women facing a cancer diagnosis.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140230/1/ten.tea.2013.0675.pd

    Retrievable hydrogels for ovarian follicle transplantation and oocyte collection

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    Cancer survivorship rates have drastically increased due to improved efficacy of oncologic treatments. Consequently, clinical concerns have shifted from solely focusing on survival to quality of life, with fertility preservation as an important consideration. Among fertility preservation strategies for female patients, ovarian tissue cryopreservation and subsequent reimplantation has been the only clinical option available to cancer survivors with cryopreserved tissue. However, follicle atresia after transplantation and risk of reintroducing malignant cells have prevented this procedure from becoming widely adopted in clinics. Herein, we investigated the encapsulation of ovarian follicles in alginate hydrogels that isolate the graft from the host, yet allows for maturation after transplantation at a heterotopic (i.e., subcutaneous) site, a process we termed in vivo follicle maturation. Survival of multiple follicle populations was confirmed via histology, with the notable development of the antral follicles. Collected oocytes (63%) exhibited polar body extrusion and were fertilized by intracytoplasmic sperm injection and standard in vitro fertilization procedures. Successfully fertilized oocytes developed to the pronucleus (14%), two‐cell (36%), and four‐cell (7%) stages. Furthermore, ovarian follicles cotransplanted with metastatic breast cancer cells within the hydrogels allowed for retrieval of the follicles, and no mice developed tumors after removal of the implant, confirming that the hydrogel prevented seeding of disease within the host. Collectively, these findings demonstrate a viable option for safe use of potentially cancer‐laden ovarian donor tissue for in vivo follicle maturation within a retrievable hydrogel and subsequent oocyte collection. Ultimately, this technology may provide novel options to preserve fertility for young female patients with cancer.The authors present an alginate hydrogel as a retrievable technology to mature ovarian follicles subcutaneously and to prevent escape and subsequent metastasis of cancer cells. Early stage follicles were transplanted within hydrogels, matured in vivo, and oocytes subsequently collected. Fertilized oocytes progressed to the 2‐cell and 4‐cell embryo stages. These findings demonstrate retrievable hydrogels as a novel approach to mature follicles and obtain fertilizable oocytes, but also to alleviate concerns related to re‐seeding disease from cryopreserved auto‐transplanted ovarian tissue.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/145292/1/bit26721_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/145292/2/bit26721.pd

    Immunoisolating poly(ethylene glycol) based capsules support ovarian tissue survival to restore endocrine function

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    A common irreversible adverse effect of life‐saving anticancer treatments is loss of gonadal endocrine function and fertility, calling for a need to focus on post‐treatment quality of life. Here, we investigated the use of poly(ethylene glycol)‐vinyl sulfone (PEG‐VS) based capsules to support syngeneic donor ovarian tissue for restoration of endocrine function in mice. We designed a dual immunoisolating capsule (PEG‐Dual) by tuning the physical properties of the PEG hydrogels and combining proteolytically degradable and nondegradable layers to meet the numerous requirements for encapsulation and immunoisolation of ovarian tissue, such as nutrient diffusion and tissue expansion. Tuning the components of the PEG‐Dual capsule to have similar physical properties allowed for concentric encapsulation. Upon implantation, the PEG‐based capsules supported ovarian tissue survival and led to a significant decrease in follicle stimulating hormone levels 60 days postimplantation. Mice that received the implants resumed regular estrous cycle activity and follicle development in the implanted grafts. The PEG‐Dual capsule provided an environment conducive for tissue survival, while providing a barrier to the host environment. This study demonstrated for the first time that immunoisolating PEG‐VS capsules can support ovarian follicular development resulting in the restoration of ovarian endocrine function and can be applied to future allogeneic studies. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1381–1389, 2018.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142967/1/jbma36338_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142967/2/jbma36338.pd
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