scholarly journals The Significance of Biomechanics and Scaffold Structure for Bladder Tissue Engineering

2021 ◽  
Vol 22 (23) ◽  
pp. 12657
Author(s):  
Marta Hanczar ◽  
Mehran Moazen ◽  
Richard Day
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Bladder Wall ◽  
Bladder Capacity ◽  
Biomechanical Properties ◽  
Bladder Tissue ◽  
Long Term Effect ◽  
Target Values ◽  
Bladder Reconstruction ◽  
The Impact

Current approaches for bladder reconstruction surgery are associated with many morbidities. Tissue engineering is considered an ideal approach to create constructs capable of restoring the function of the bladder wall. However, many constructs to date have failed to create a sufficient improvement in bladder capacity due to insufficient neobladder compliance. This review evaluates the biomechanical properties of the bladder wall and how the current reconstructive materials aim to meet this need. To date, limited data from mechanical testing and tissue anisotropy make it challenging to reach a consensus on the native properties of the bladder wall. Many of the materials whose mechanical properties have been quantified do not fall within the range of mechanical properties measured for native bladder wall tissue. Many promising new materials have yet to be mechanically quantified, which makes it difficult to ascertain their likely effectiveness. The impact of scaffold structures and the long-term effect of implanting these materials on their inherent mechanical properties are areas yet to be widely investigated that could provide important insight into the likely longevity of the neobladder construct. In conclusion, there are many opportunities for further investigation into novel materials for bladder reconstruction. Currently, the field would benefit from a consensus on the target values of key mechanical parameters for bladder wall scaffolds.

The relationship between the mechanical properties and cell behaviour on PLGA and PCL scaffolds for bladder tissue engineering

Biomaterials ◽  
2009 ◽  
Vol 30 (7) ◽  
pp. 1321-1328 ◽  
Author(s):  
Simon C. Baker ◽  
Géraldine Rohman ◽  
Jennifer Southgate ◽  
Neil R. Cameron
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Bladder Tissue ◽  
Cell Behaviour ◽  
The Relationship

scholarly journals Non-Traditional Management of the Neurogenic Bladder: Tissue Engineering and Neuromodulation

2007 ◽  
Vol 7 ◽  
pp. 1230-1241 ◽  
Author(s):  
Jane M. Lewis ◽  
Earl Y. Cheng
Keyword(s):  
Tissue Engineering ◽  
Spina Bifida ◽  
Neurogenic Bladder ◽  
Cell Biology ◽  
Bladder Wall ◽  
Bladder Augmentation ◽  
Current Status ◽  
Urinary Continence ◽  
Clean Intermittent Catheterization ◽  
Bladder Tissue

Patients with spina bifida and a neurogenic bladder have traditionally been managed with clean intermittent catheterization and pharmacotherapy in order to treat abnormal bladder wall dynamics, protect the upper urinary tract from damage, and achieve urinary continence. However, some patients will fail this therapy and require surgical reconstruction in the form of bladder augmentation surgery using reconfigured intestine or stomach to increase the bladder capacity while reducing the internal storage pressure. Despite functional success of bladder augmentation in achieving a low pressure reservoir, there are several associated complications of this operation and patients do not have the ability to volitionally void. For these reasons, alternative treatments have been sought. Two exciting alternative approaches that are currently being investigated are tissue engineering and neuromodulation. Tissue engineering aims to create new bladder tissue for replacement purposes with both “seeded” and “unseeded” technology. Advances in the fields of nanotechnology and stem cell biology have further enhanced these tissue engineering technologies. Neuromodulation therapies directly address the root of the problem in patients with spina bifida and a neurogenic bladder, namely the abnormal relationship between the nerves and the bladder wall. These therapies include transurethral bladder electrostimulation, sacral neuromodulation, and neurosurgical techniques such as selective sacral rhizotomy and artificial somatic-autonomic reflex pathway construction. This review will discuss both tissue engineering techniques and neuromodulation therapies in more detail including rationale, experimental data, current status of clinical application, and future direction.

scholarly journals Construction of a vascularized bladder with autologous adipose-derived stromal vascular fraction cells combined with bladder acellular matrix via tissue engineering

2019 ◽  
Vol 10 ◽  
pp. 204173141989125 ◽  
Author(s):  
Feng Zhao ◽  
Liuhua Zhou ◽  
Jingyu Liu ◽  
Zhongle Xu ◽  
Wenwen Ping ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Wnt Signaling Pathway ◽  
Stromal Vascular Fraction ◽  
Functional Restoration ◽  
Bladder Tissue ◽  
Acellular Matrix ◽  
Bam Complex ◽  
Cell Source ◽  
Bladder Reconstruction ◽  
The Stability

The formation of an effective vascular network can promote peripheral angiogenesis, ensuring an effective supply of blood, oxygen, and nutrients to an engineered bladder, which is important for bladder tissue engineering. Stromal vascular fraction cells (SVFs) promote vascularization and improve the function of injured tissues. In this study, adipose tissue-derived SVFs were introduced as an angiogenic cell source and seeded into the bladder acellular matrix (BAM) to generate a SVF-BAM complex for bladder reconstruction. The morphological regeneration and functional restoration of the engineered bladder were evaluated. In addition, we also explored the role of the Wnt5a/sFlt-1 noncanonical Wnt signaling pathway in regulating the angiogenesis of SVFs, and in maintaining the rational capability of SVFs to differentiate into vasculature in regenerated tissues. Histological assessment indicated that the SVF-BAM complex was more effective in promoting smooth muscle, vascular, and nerve regeneration than BAM alone and subsequently led to the restoration of bladder volume and bladder compliance. Moreover, exogenous Wnt5a was able to enhance angiogenesis by increasing the activity of MMP2, MMP9, and VEGFR2. Simultaneously, the expression of sFlt-1 was also increased, which enhanced the stability of the SVFs angiogenic capability. SVFs may be a potential cell source for tissue-engineered bladders. The Wnt5a/sFlt-1 pathway is involved in the regulation of autologous vascular formation by SVFs. The rational regulation of this pathway can promote neo-microvascularization in tissue-engineered bladders.

scholarly journals Spheroids of Bladder Smooth Muscle Cells for Bladder Tissue Engineering

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Tim Gerwinn ◽  
Souzan Salemi ◽  
Lisa Krattiger ◽  
Daniel Eberli ◽  
Maya Horst
Keyword(s):  
Tissue Engineering ◽  
Smooth Muscle ◽  
Myogenic Differentiation ◽  
Bladder Wall ◽  
Building Blocks ◽  
Culture Conditions ◽  
Bladder Smooth Muscle ◽  
Bladder Tissue ◽  
Primary Bladder ◽  
Differentiation Marker

Cell-based tissue engineering (TE) has been proposed to improve treatment outcomes in end-stage bladder disease, but TE approaches with 2D smooth muscle cell (SMC) culture have so far been unsuccessful. Here, we report the development of primary bladder-derived 3D SMC spheroids that outperform 2D SMC cultures in differentiation, maturation, and extracellular matrix (ECM) production. Bladder SMC spheroids were compared with 2D cultures using live-dead staining, qRT-PCR, immunofluorescence, and immunoblotting to investigate culture conditions, contractile phenotype, and ECM deposition. The SMC spheroids were viable for up to 14 days and differentiated rather than proliferating. Spheroids predominantly expressed the late myogenic differentiation marker MyH11, whereas 2D SMC expressed more of the general SMC differentiation marker α-SMA and less MyH11. Furthermore, the expression of bladder wall-specific ECM proteins in SMC spheroids was markedly higher. This first establishment and analysis of primary bladder SMC spheroids are particularly promising for TE because differentiated SMCs and ECM deposition are a prerequisite to building a functional bladder wall substitute. We were able to confirm that SMC spheroids are promising building blocks for studying detrusor regeneration in detail and may provide improved function and regenerative potential, contributing to taking bladder TE a significant step forward.

scholarly journals Decellularized tracheal scaffolds in tracheal reconstruction: An evaluation of different techniques

2021 ◽  
Vol 19 ◽  
pp. 228080002110649
Author(s):  
Chenyang Lei ◽  
Sheng Mei ◽  
Chun Zhou ◽  
Chen Xia
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Structure And Function ◽  
Future Research ◽  
Natural Structure ◽  
Tracheal Reconstruction ◽  
Good Biocompatibility ◽  
And Function ◽  
The Impact

In humans, the trachea is a conduit for ventilation connecting the throat and lungs. However, certain congenital or acquired diseases may cause long-term tracheal defects that require replacement. Tissue engineering is considered a promising method to reconstruct long-segment tracheal lesions and restore the structure and function of the trachea. Decellularization technology retains the natural structure of the trachea, has good biocompatibility and mechanical properties, and is currently a hotspot in tissue engineering studies. This article lists various recent representative protocols for the generation of decellularized tracheal scaffolds (DTSs), as well as their validity and limitations. Based on the advancements in decellularization methods, we discussed the impact and importance of mechanical properties, revascularization, recellularization, and biocompatibility in the production and implantation of DTS. This review provides a basis for future research on DTS and its application in clinical therapy.

Active Biaxial Mechanical Properties of Bladder Wall Tissue

2003 ◽  
Author(s):  
Jiro Nagatomi ◽  
Michael B. Chancellor ◽  
Michael S. Sacks
Keyword(s):  
Mechanical Properties ◽  
Smooth Muscle ◽  
Urinary Bladder ◽  
Muscle Tone ◽  
Bladder Wall ◽  
Upper Urinary Tract ◽  
Biaxial Stress ◽  
Bladder Tissue ◽  
Biaxial Mechanical Properties

The urinary bladder is a smooth muscle organ whose main functions are to store and to void urine. Since the most important aspect of the storage function of the bladder is to maintain low intravesical pressure in order to protect the upper urinary tract from backflow of urine, the compliance of the bladder wall is one of the key functional paramters to assess the health of this organ. Previously, our laboratory reported, for the first time, the biaxial mechanical properties of bladder wall tissue in the inactive state (in the absence of calcium in the testing bath solution and thus smooth muscle contraction was abolished) (Gloeckner et al. 2002). The bladder in vivo, however, normaly exhibits passive smooth muscle tone during filling and active contraction during voiding. Therefore, in order to completely characterize the bladder tissue mechanical behaviors, it is necessary to examine the load-deformation relationship of the bladder under the passive and active states. In the present study, a novel experimental model was designed to allow collection of biaxial stress-strain data from urinary bladder wall tissue under passive, active and inactive states.

scholarly journals Tissue-engineered autologous peritoneal grafts for bladder reconstruction in a porcine model

2021 ◽  
Vol 12 ◽  
pp. 204173142098679
Author(s):  
Biao Chen ◽  
Xia Chen ◽  
Wenjia Wang ◽  
Jun Shen ◽  
Zhiqiang Song ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Morphological Characteristics ◽  
Normal Function ◽  
Future Research ◽  
Control Group ◽  
Bladder Tissue ◽  
Promising Alternative ◽  
Ileal Neobladder ◽  
New Strategy ◽  
Bladder Reconstruction

Ileal neobladder construction is a common treatment for patients with bladder cancer after radical cystectomy. However, metabolic disorders caused by transposed bowel segments occur frequently. Bladder tissue engineering is a promising alternative approach. Although numerous studies have reported bladder reconstruction using acellular and cellular scaffolds, there are also disadvantages associated with these methods, such as immunogenicity of synthetic grafts and incompatible mechanical properties of the biomaterials. Here, we engineered an autologous peritoneal graft consisting of a peritoneal sheet and the seromuscular layer from the ileum. Three months after the surgery, compared with the neobladder made from the ileum, the reconstructed neobladder using our new method showed normal function and better gross morphological characteristics. Moreover, histopathological and transcriptomic analysis revealed urothelium-like cells expressing urothelial biomarkers appeared in the neobladder, while no such changes were observed in the control group. Overall, our study provides a new strategy for bladder tissue engineering and informs a variety of future research prospects.

scholarly journals Urinary bladder reconstruction using autologous collagenous connective tissue membrane “Biosheet” induced by in-body tissue architecture

2019 ◽  
Author(s):  
Yasumasa Iimori ◽  
Kazuma Naito ◽  
Ryosuke Iwai ◽  
Kengo Nagatani ◽  
Yuka Inoue ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Urinary Bladder ◽  
Bladder Wall ◽  
Body Tissue ◽  
Repair Material ◽  
Efficacy And Safety ◽  
Tissue Architecture ◽  
Engineering Technology ◽  
Bladder Reconstruction ◽  
Tissue Engineering Technology

Abstract Background: Tissue engineering technology has the potential for bladder reconstruction without complications. We have previously developed autologous collagenous prosthetic tissues using in-body tissue architecture (iBTA). This is a cell-free tissue engineering technology that can produce autologous implantable tissues be a desired shape by simple subcutaneous embedding of a specially designed mold. Grafts formed by iBTA can be made in any shape and form, including sheet-shaped tissues (Biosheet). In this study, we evaluated the efficacy and safety of autologous Biosheet as bladder repair material in a canine bladder defect model. Methods: We studied four healthy adult beagles (1-2 years old, 9.3-9.9 kg). Autologous Biosheets were prepared by embedding specially designed molds into subcutaneous pouches in the beagles. Eight weeks after implantation, the molds were extracted, and collagenous connective tissues surrounding the molds were harvested as autologous Biosheet. The urinary bladder wall was excised (2 cm × 2 cm) and autologous Biosheets were sutured to the cut edge of the native bladder using a simple continuous suture pattern. The efficacy of implantation of the Biosheets was evaluated by physical examination, blood tests, abdominal ultrasound, urinalysis, and urography, at 0, 1, 3, 7, 14, 28, 56, and 84 days after the implantation. The Biosheets were extracted at 28 days (n=1) and 84 days (n=3) after implantation. Results: No side-effects were observed during follow-up. No disruption of the sheet or any urinary leakage into the peritoneal cavity was observed. Histological analysis revealed α-SMA-positive muscle fibers at the margin of the Biosheets, indicating regeneration of the urinary bladder tissue. Conclusion: This is the first report evaluating the efficacy and safety of iBTA-induced autologous “Biosheets” as a bladder repair material in a canine model. In summary, autologous Biosheets could be useful biomaterials for urological reconstruction.

Novel titanium foam for bone tissue engineering

2002 ◽  
Vol 17 (10) ◽  
pp. 2633-2639 ◽  
Author(s):  
C. E. Wen ◽  
Y. Yamada ◽  
K. Shimojima ◽  
Y. Chino ◽  
H. Hosokawa ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Biomechanical Properties ◽  
Good Ability ◽  
Thermochemical Process ◽  
Human Cancellous Bone ◽  
Titanium Foam ◽  
Bonelike Apatite

Titanium foams fabricated by a new powder metallurgical process have bimodal pore distribution architecture (i.e., macropores and micropores), mimicking natural bone. The mechanical properties of the titanium foam with low relative densities of approximately 0.20–0.30 are close to those of human cancellous bone. Also, mechanical properties of the titanium foams with high relative densities of approximately 0.50–0.65 are close to those of human cortical bone. Furthermore, titanium foams exhibit good ability to form a bonelike apatite layer throughout the foams after pretreatment with a simple thermochemical process and then immersion in a simulated body fluid. The present study illustrates the feasibility of using the titanium foams as implant materials in bone tissue engineering applications, highlighting their excellent biomechanical properties and bioactivity.

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