Therapeutic potential of adipose-derived mesenchymal stem cell exosomes in tissue-engineered bladders

Mesenchymal stem cells (MSCs) are a therapeutic tool for tissue engineering. However, many studies have recently shown that the therapeutic effects of MSCs are mediated by paracrine signaling and their secretory factors rather than their multidirectional differentiation ability. Exosomes isolated from the conditioned medium of MSCs are considered the main intercellular communication medium between MSCs and their target cells. Exosomes have been utilized in a novel cell-free therapy strategy that has attracted much attention. In this study, we evaluated the effects of a new cell-free tissue-engineered bladder (bladder acellular matrix combined with adipose-derived mesenchymal stem cell exosomes (AMEs)) in vivo and in vitro to prove that AMEs promoted tissue regeneration and functional recovery in a rat bladder replacement model.

Urinary diversion after pelvic exenteration for gynecologic malignancies

Pelvic exenteration combines multiple organ resections and functional reconstruction. Many techniques have been described for urinary reconstruction, although only a few are routinely used. The aim of this review is to focus beyond the technical aspects and the advantages and disadvantages of each technique, and to include a critical analysis of continent techniques in the gynecologic and urologic literature. Selecting a technique for urinary reconstruction must take into account the constraints entailed by the natural history of the disease, patient characteristics, healthcare institution, and surgeon experience. In gynecologic oncology, the Bricker ileal conduit is the most commonly employed diversion, followed by the self-catheterizable pouch and orthotopic bladder replacement. Continent and non-continent diversions present similar immediate and long-term complication rates, including lower tract urinary infections and pyelonephritis (5–50%), ureteral stricture (3–27%), urolithiasis (5–25%), urinary fistula (5%), and more rarely, vitamin B12 deficiency and metabolic acidosis. Urinary incontinence for the ileal orthotopic neobladder (50%), stoma-related complications for the Bricker ileal conduit (24%), difficulty with self-catheterization (18%) for the continent pouch, and induction of secondary malignancy for the ureterosigmoidostomy (3%) are the most relevant technique-related complications following urinary diversion. The self-catheterizable pouch and orthotopic bladder require a longer learning curve from the surgical team and demand adaptation from the patient compared with the ileal conduit. Quality of life between different techniques remains controversial, although it would seem that young patients may benefit from continent diversions. We consider that centralization of pelvic exenteration in referral centers is crucial to optimize the oncologic and functional outcomes of complex ablative reconstructive surgery.

Design of a Mechatronics Model of Urinary Bladder and Realization and Evaluation of Its Prototype

Annually, there are many bladder cancer patients undergoing radical cystectomy (RC) with urinary diversion worldwide. Until 2019, intestinal cystoplasty is still the gold standard for bladder replacement, but this therapy is always associated with severe complications. An ideal bladder substitute without using intestinal tissue remains a challenge today. In this work, an artificial mechatronics bladder (AMB) as a brand new bladder replacement approach is developed. We studied the main physiological function characteristics of a natural urinary bladder from teaching books and relevant papers. According to these characteristics, we completed an overall design of AMB and made a prototype in lab. The prototype successfully realized the functions of a natural bladder in vitro. It can expand to store urine in real time when urine is flowing into it. It can send a urination alarm when it is fully filled and can void urine automatically after receiving remote control signals. According to relevant papers and our test experience, if the prototype could be smaller and lighter and manufactured with good biocompatibility materials such as PTFE, we think it is possible for AMB to be implanted in an animal’s body, and we deduce AMB could realize the functions of a natural urinary bladder in vivo. After thorough validation from animal testing, we hope AMB can be a good clinical option for bladder removal patients in the future.