The effect of hyperosmolar stimuli and cyclophosphamide on the culture of normal rat urothelial cells in vitro

Chemical hemorrhagic cystitis: Diagnostic and therapeutic pitfalls (Review)

Chemical cystitis (CC) is an inflammation of the bladder caused by various chemical agents ingested intentionally or accidentally. It is linked to chemotherapeutic agents such as cyclophosphamide, therapeutic agents for diverse diseases, and anesthetic agents consumed abusively for recreational effects such as ketamine, or can be linked to environmental and surrounding factors such as soaps, gels, spermicides, and dyes. CC is a pathology with an increasing incidence that is inadequately treated due to its infectious cystitis-like symptoms. The hemorrhagic form can have a rampant evolution. Treatment options of CC and its complications are under continuous research with no accepted standardized sequence. In many situations, the treatments are difficult to obtain, administer, and follow-up. In addition, the lack of experience of the physician may pose other obstacles in delivering treatment to the patient. In conclusion, CC is a disease with an increasing incidence, challenging to diagnose, which is frequently mistreated, and has multiple treatment modalities that still require standardization in administration and sequencing.

Bladder tissue engineering: a literature review

PURPOSE OF REVIEW

In bladder cancer and neuro-bladder, reconstruction of the bladder requires bowel segment grafting for augmentation cystoplasty or neo-bladder creation. However, even if currently considered as the gold standard, it is associated with potentially severe short- and long-term adverse effects. Thus, bladder tissue engineering is a promising approach to bladder reconstruction.

RECENT FINDINGS

In the last few years, progress has been made with the development of new biomaterials for bladder tissue replacement and in deciphering the role of stem cells as well as their contribution to bladder scaffold integration and tissue regeneration.

SUMMARY

This review of recently published articles allows us to forecast the characteristics of efficient and safe bladder biomaterials. However, several factors, such as native bladder traits, the specific involvement of urine, and bladder tissue replacement indications, have to be assessed with caution before including bladder tissue engineering in clinical trials. Many authors agree that these challenging techniques could deliver significant benefits with clinical application, reducing morbidity and global long-term costs.

Mechanisms of hemorrhagic cystitis

The vast majority of cases of infectious cystitis are easily treated, and most patients have no long-term complications. However, hemorrhagic cystitis is a potentially deadly complication associated with pelvic radiation therapy, chemotherapy, and stem-cell transplant therapy. The focus of current understanding, and hence therapy, is directed toward urothelial cell death. However, the primary functional ramification of inflammatory bladder disease is the loss of compliance due to muscular expansion. Recent studies on smooth muscle response in models of bladder inflammation demonstrate a process of pyroptotic cell death that potentiates further muscle hyperplasia. These findings may support alternative interventions for subjects with hemorrhagic cystitis refractive to current therapy.

Biomimetic urothelial tissue models for the in vitro evaluation of barrier physiology and bladder drug efficacy

The bladder is an important tissue in which to evaluate xenobiotic drug interactions and toxicities due to the concentration of parent drug and hepatic/enteric-derived metabolites in the urine as a result of renal excretion. Breaching of the barrier provided by the bladder epithelial lining (the urothelium) can expose the underlying tissues to urine and cause harmful effects (e.g., cystitis or cancer). Human urothelium is most commonly represented in vitro as immortalized or established cancer-derived cell lines, but the compromised ability of such cells to undergo differentiation and barrier formation means that nonimmortalized, normal human urothelial (NHU) cells provide a more relevant cell culture system. The impressive capacity for urothelial self-renewal in vivo can be harnessed in vitro to generate experimentally-useful quantities of NHU cells, which can subsequently be differentiated to form a functional or "biomimetic" urothelium. When seeded onto permeable membranes, these barrier-forming human urothelial tissue models enable the modeling of serum and luminal (intravesical) exposure to drugs and metabolites, thus supporting efficacy/toxicity assessments. Biomimetic human urothelial constructs provide a potential step along the preclinical trail and may support the extrapolation from rodent in vivo data to determine human relevance. Early evidence is beginning to demonstrate that human urothelium in vitro can provide information that supersedes conventional rodent studies, but further validation is needed to support widespread adoption.