An Investigation of Nano-structured Polymers for Use as Bladder Tissue Replacement Constructs

2001 ◽  
Vol 711 ◽  
Author(s):  
Anil Thapa ◽  
Thomas J. Webster ◽  
Karen M. Haberstroh

ABSTRACTConventionally, studies investigating the design of synthetic bladder wall substitutes have involved polymers with micro-dimensional structures. Since the body is made up of nano-structured components (e.g., extracellular matrix proteins), our focus has been in the use of nano-structured polymers in order to design a three-dimensional synthetic bladder construct that mimics bladder tissue in vivo. In order to complete this task, we fabricated novel, nano-structured, biodegradable materials to serve as substrates for bladder tissue constructs and tested the cytocompatibility properties of these biomaterials in vitro. The results from our in vitro work to date have provided the first evidence that cellular responses (such as adhesion and proliferation) of bladder smooth muscle cells are enhanced as poly (lactic-co-glycolic acid) (PLGA) surface feature dimensions are reduced into the nanometer range.

2007 ◽  
Vol 539-543 ◽  
pp. 540-544
Author(s):  
Karen M. Haberstroh ◽  
Megan A. Pattison ◽  
Martin Kaefer ◽  
Thomas J. Webster

Superficial bladder cancer is often treated by removing the cancerous portion of the bladder wall combined with immuno-chemotherapy; in more extreme cases, it is often necessary to remove the entire bladder wall. This diagnosis brings an obvious need for bladder tissue replacement designs with a high degree of efficacy. Since bladder cells are accustomed to interacting with extracellular matrix proteins having dimensions on the nanometer scale, this study aimed to design the next generation of tissue-engineered bladder replacement constructs with nanometer (less than 100 nm) surface features. For this purpose, porous and biodegradable PLGA and PU scaffolds were treated with various concentrations of NaOH or HNO3, respectively, for various periods of time to create nanometer surface roughness. Resulting surface properties were characterized using SEM (to visualize scaffold properties) and BET. Cell experiments conducted on these polymeric scaffolds provided evidence of enhanced bladder smooth muscle cell attachment, growth, and elastin/collagen production (critical extracellular matrix proteins in the bladder tissue regeneration process) as surface feature dimensions were reduced into the nanometer regime. In vivo augmentation surgeries with nano-structured PLGA and PU patches will provide further information regarding total bladder capacity, anastomotic integrity, burst pressure, epithelialization, muscular ingrowth, and neovascularization. In vitro and in vivo proof of material usefulness and technique would provide urologists with a readily accessible graft for bladder tissue replacement applications.


2021 ◽  
Vol 22 (2) ◽  
pp. 830
Author(s):  
Georgia Pennarossa ◽  
Sharon Arcuri ◽  
Teresina De Iorio ◽  
Fulvio Gandolfi ◽  
Tiziana A. L. Brevini

Bi-dimensional culture systems have represented the most used method to study cell biology outside the body for over a century. Although they convey useful information, such systems may lose tissue-specific architecture, biomechanical effectors, and biochemical cues deriving from the native extracellular matrix, with significant alterations in several cellular functions and processes. Notably, the introduction of three-dimensional (3D) platforms that are able to re-create in vitro the structures of the native tissue, have overcome some of these issues, since they better mimic the in vivo milieu and reduce the gap between the cell culture ambient and the tissue environment. 3D culture systems are currently used in a broad range of studies, from cancer and stem cell biology, to drug testing and discovery. Here, we describe the mechanisms used by cells to perceive and respond to biomechanical cues and the main signaling pathways involved. We provide an overall perspective of the most recent 3D technologies. Given the breadth of the subject, we concentrate on the use of hydrogels, bioreactors, 3D printing and bioprinting, nanofiber-based scaffolds, and preparation of a decellularized bio-matrix. In addition, we report the possibility to combine the use of 3D cultures with functionalized nanoparticles to obtain highly predictive in vitro models for use in the nanomedicine field.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Mostafa Elsaadany ◽  
Matthew Harris ◽  
Eda Yildirim-Ayan

It is crucial to replicate the micromechanical milieu of native tissues to achieve efficacious tissue engineering and regenerative therapy. In this study, we introduced an innovative loading platform, EQUicycler, that utilizes a simple, yet effective, and well-controlled mechanism to apply physiologically relevant homogenous mechanical equiaxial strain on three-dimensional cell-embedded tissue scaffolds. The design of EQUicycler ensured elimination of gripping effects through the use of biologically compatible silicone posts for direct transfer of the mechanical load to the scaffolds. Finite Element Modeling (FEM) was created to understand and to quantify how much applied global strain was transferred from the loading mechanism to the tissue constructs. In vitro studies were conducted on various cell lines associated with tissues exposed to equiaxial mechanical loading in their native environment. In vitro results demonstrated that EQUicycler was effective in maintaining and promoting the viability of different musculoskeletal cell lines and upregulating early differentiation of osteoprogenitor cells. By utilizing EQUicycler, collagen fibers of the constructs were actively remodeled. Residing cells within the collagen construct elongated and aligned with strain direction upon mechanical loading. EQUicycler can provide an efficient and cost-effective tool to conduct mechanistic studies for tissue engineered constructs designed for tissue systems under mechanical loading in vivo.


2021 ◽  
Vol 3 ◽  
Author(s):  
Astia Rizki-Safitri ◽  
Fumiya Tokito ◽  
Masaki Nishikawa ◽  
Minoru Tanaka ◽  
Kazuya Maeda ◽  
...  

The liver plays a pivotal role in the clearance of drugs. Reliable assays for liver function are crucial for various metabolism investigation, including toxicity, disease, and pre-clinical testing for drug development. Bile is an aqueous secretion of a functioning liver. Analyses of bile are used to explain drug clearance and related effects and are thus important for toxicology and pharmacokinetic research. Bile fluids collection is extensively performed in vivo, whereas this process is rarely reproduced as in the in vitro studies. The key to success is the technology involved, which needs to satisfy multiple criteria. To ensure the accuracy of subsequent chemical analyses, certain amounts of bile are needed. Additionally, non-invasive and continuous collections are preferable in view of cell culture. In this review, we summarize recent progress and limitations in the field. We highlight attempts to develop advanced liver cultures for bile fluids collection, including methods to stimulate the secretion of bile in vitro. With these strategies, researchers have used a variety of cell sources, extracellular matrix proteins, and growth factors to investigate different cell-culture environments, including three-dimensional spheroids, cocultures, and microfluidic devices. Effective combinations of expertise and technology have the potential to overcome these obstacles to achieve reliable in vitro bile assay systems.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Jianqun Ma ◽  
Kyle Holden ◽  
Jinhong Zhu ◽  
Haiying Pan ◽  
Yong Li

Three-dimensional (3D) engineered tissue constructs are a novel and promising approach to tissue repair and regeneration. 3D tissue constructs have the ability to restore form and function to damaged soft tissue unlike previous methods, such as plastic surgery, which are able to restore only form, leaving the function of the soft tissue often compromised. In this study, we seeded murine myoblasts (C2C12) into a collagen composite scaffold and cultured the scaffold in a roller bottle cell culture system in order to create a 3D tissue graftin vitro. The 3D graft createdin vitrowas then utilized to investigate muscle tissue repairin vivo. The 3D muscle grafts were implanted into defect sites created in the skeletal muscles in mice. We detected that the scaffolds degraded slowly over time, and muscle healing was improved which was shown by an increased quantity of innervated and vascularized regenerated muscle fibers. Our results suggest that the collagen composite scaffold seeded with myoblasts can create a 3D muscle graftin vitrothat can be employed for defect muscle tissue repairin vivo.


2017 ◽  
Vol 4 (4) ◽  
pp. 194-200
Author(s):  
M. T Aleksandrov ◽  
Vladimir M. Zuev ◽  
Yu. I Pimancheva ◽  
E. P Pashkov ◽  
G. E Bagramova

There were executed experimental studies on test subjects of microbial (Staphylococcus aureus and Pseudomonas aeruginosa) and neoplastic nature (in vitro - suspension of cells of the line of chronic myelogenous leukemia K562 in a volume of 60 μl and in an amount of 60 ± 1 × 103, in vivo - mice infected with Ehrlich carcinoma) on the substantiation the use of chlorophyll-containing drugs activated for photodynamic therapy (PDT) outside the biological object. No additional PDT activation of the drug was performed.The high bactericidal (on the test objects of microbes) and anti-tumor PDT efficacy of chlorophyll-containing preparations activated outside the organism was substantiated, with their subsequent administration per os and accumulation in practically all organs and tissues of the body was validated. The developed medical diagnostic technology in its clinical application has proved its effectiveness in women with inflammatory and/or neoplastic processes of the pelvic organs. The used equipment and preparation are approved for clinical use.


Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.


2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.


Author(s):  
А.А. Раецкая ◽  
С.В. Калиш ◽  
С.В. Лямина ◽  
Е.В. Малышева ◽  
О.П. Буданова ◽  
...  

Цель исследования. Доказательство гипотезы, что репрограммированные in vitro на М3 фенотип макрофаги при введении в организм будут существенно ограничивать развитие солидной карциномы in vivo . Методика. Рост солидной опухоли инициировали у мышей in vivo путем подкожной инъекции клеток карциномы Эрлиха (КЭ). Инъекцию макрофагов с нативным М0 фенотипом и с репрограммированным M3 фенотипом проводили в область формирования солидной КЭ. Репрограммирование проводили с помощью низких доз сыворотки, блокаторов факторов транскрипции STAT3/6 и SMAD3 и липополисахарида. Использовали две схемы введения макрофагов: раннее и позднее. При раннем введении макрофаги вводили на 1-е, 5-е, 10-е и 15-е сут. после инъекции клеток КЭ путем обкалывания макрофагами с четырех сторон область развития опухоли. При позднем введении, макрофаги вводили на 10-е, 15-е, 20-е и 25-е сут. Через 15 и 30 сут. после введения клеток КЭ солидную опухоль иссекали и измеряли ее объем. Эффект введения макрофагов оценивали качественно по визуальной и пальпаторной характеристикам солидной опухоли и количественно по изменению ее объема по сравнению с группой без введения макрофагов (контроль). Результаты. Установлено, что M3 макрофаги при раннем введении от начала развития опухоли оказывают выраженный антиопухолевый эффект in vivo , который был существенно более выражен, чем при позднем введении макрофагов. Заключение. Установлено, что введение репрограммированных макрофагов M3 ограничивает развитие солидной карциномы в экспериментах in vivo . Противоопухолевый эффект более выражен при раннем введении М3 макрофагов. Обнаруженные в работе факты делают перспективным разработку клинической версии биотехнологии ограничения роста опухоли, путем предварительного программирования антиопухолевого врожденного иммунного ответа «в пробирке». Aim. To verify a hypothesis that macrophages reprogrammed in vitro to the M3 phenotype and injected into the body substantially restrict the development of solid carcinoma in vivo . Methods. Growth of a solid tumor was initiated in mice in vivo with a subcutaneous injection of Ehrlich carcinoma (EC) cells. Macrophages with a native M0 phenotype or reprogrammed towards the M3 phenotype were injected into the region of developing solid EC. Reprogramming was performed using low doses of serum, STAT3/6 and SMAD3 transcription factor blockers, and lipopolysaccharide. Two schemes of macrophage administration were used: early and late. With the early administration, macrophages were injected on days 1, 5, 10, and 15 following the injection of EC cells at four sides of the tumor development area. With the late administration, macrophages were injected on days 10, 15, 20, and 25. At 15 and 30 days after the EC cell injection, the solid tumor was excised and its volume was measured. The effect of macrophage administration was assessed both qualitatively by visual and palpation characteristics of solid tumor and quantitatively by changes in the tumor volume compared with the group without the macrophage treatment. Results. M3 macrophages administered early after the onset of tumor development exerted a pronounced antitumor effect in vivo , which was significantly greater than the antitumor effect of the late administration of M3 macrophages. Conclusion. The observed significant inhibition of in vivo growth of solid carcinoma by M3 macrophages makes promising the development of a clinical version of the biotechnology for restriction of tumor growth by in vitro pre-programming of the antitumor, innate immune response.


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