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regenerative medicine in urology latest .pptx
- 1. DR MAYANK YADAV MODERATOR – DR SOMENDRA BANSAL REGENERATIVE MEDICINE IN UROLOGY
- 2. William Haseltine, then the Scientific Founder and CEO of Human Genome Sciences, coined the term Regenerative medicine
- 4. Cells used Somatic cells Stem cells Limited proliferative ability ESC Induced pluripotent stem cells Somatic stem cells Perinatal stem cells/ fetal stem
- 5. Embryonic Stem Cells Totipotent cells Technique for the generation of embryonic stem cell lines 1. Performing a single-cell embryo biopsy. 2. Obtaining cells from arrested embryos 3. Somatic cell nuclear transfer Ethical issue Teratoma Immunological rejection
- 6. Induced Pluripotent Stem Cells No ethical issue No immunological rejection
- 7. Adult Stem Cells/ somatic stem cell Multipotent Isolated from various tissues Hematopoeitic stem cell, MSC
- 8. Mesenchymal stem cell(MSC) Mc used immunomodulatory MSCs can be found in many tissues in large quantities Bone marrow mesenchymal stem cells Adipose derived mesenchymal cells
- 9. Perinatal Stem Cells Amniotic fluid and placental–derived stem (AFPS) cells Umbilical cord blood Multiple differentiating ability Less immunogenicity
- 10. Scaffolds What are they ? Importance
- 11. Ideal scaffold • Adequate intrinsic physical and mechanical property • Biocompatibility • Bioactivity • Mimic ECM • Bioabsorption • Versatility • Reproducible
- 12. Synthetic matrices : • PGA, PLGA • advg Natural materials collagen, polysaccharides, fibrin, gelatin , cellulose Acellular matrices • mc • Preparation • sources 3D bioprinting
- 13. Vascularization Limiting factor of engineered tissue Importance engineering large complex tissues, and possibly internal organs Three approaches 1. Incorporation of angiogenic factors 2. Seeding ECs 3. Prevascularization
- 14. Soluble signals/ bioactive factors Soluble biomolecules Growth factors Cell adhesive molecules Chemokines Metalloprotein Importance cell viability cellular phenotype derive lineage specific differentiation
- 15. Tissue engineering in urology
- 17. TISSUE ENGINEERING OF URETHRA Congenital defects or post traumatic defects. Why do we need it ?
- 18. Urethra Naturally derived collagen based materials such as Woven meshes of PGA without cells and with cells Bladder derived acellular submucosa (BAM) Acellular urethral submucosa Collagen gels
- 19. Raya – Rivera et al 5 boys with urethral injuries Autolgous cells → seeded in two layers on tubularised PGA scaffoldings
- 20. Results Engineered urethras were able to show adequate anatomy, both by urethroscopy and by urethrography and function in long term
- 21. re
- 22. 6 patients (age 14 – 44 months) Cells harvested by cathetrisation and bladder lavage Lab cultured → seeded onto allogenic acellular dermis results→ 3 pts developed complications (fistula and stricture) Conclusion - selected gp
- 23. Urinary bladder reconstruction Why we need it ? Regenerated bladder should Compliant muscular wall Well differentiated urothelium Acellular v/s cellular approach
- 24. Acellular approach Theory → scaffold recruits cells for new tissue formation Commonly used in studies BAM SIS Results →non seeded scaffolds fail to show full regeneration of the bladder wall Reason for failure→ early exposure of scaffold and newly implanted cells to urine, extensive scarring within graft,
- 26. Acellular vs Cellular Oberpenning et al Canine model 3 groups Subtotal cystectomy subtotal cystectomy with non seeded scaffolds Subtotal cystectomy with seeded scaffold Results Cell seeded allogenic acellular bladder matrice showed better tissue regeneration.
- 27. First clinical trial of an engineered organ being implanted in human 9 pts of myelomeningocele Engineered human bladder tissue Autologous bladder biopsies Biodegradable 3 D matrix→ collagen vs collagen and PGA f/u →46 months→ no metabolic complications/ stones/ mucus/ renal functions are preserved
- 28. Conclusion Composite scaffolds with omental wraps best results Important step in transfer of tissue engineering technology in clinical setting However, improvements in capacity not analogous to those achiwved by
- 29. Autologous seeded biodegradable scaffold (tengion) for bladder augmentation Outcomes Compliance Capacity Results 5 pt improved compliance Complications- all Conclusion
- 30. Replace ileal conduit with lab grown conduit Tengion’s neourinary conduit
- 31. Bladder Cell Therapies injectable therapy UI VUR Autologous smooth muscle cells Myoblasts Study Bladder exstrophy patients with UI 88% socially dry
- 32. Ureters challenges Scaffold Various animal studies Non seeded acellular grafts Cells seeded biodegradable polymer scaffolds Hybrid scaffolds 3D printing (poly 2 hydroxyethyl methylacrylate hydrogel)
- 33. Male Genital and Reproductive Tissues ED / Peyronie disease Conceptual Goals penile cell therapy ( muscle derived SC / adipose derived cells) Reconstruction of corporeal smooth muscle Engineered penile prosthesis .
- 34. Testis – leydig cells Patients with testicular dysfunction / anorchic ART Approaches Transplanting Leydig cells (microencapsulated in an alginate- poly- L- Lysine solution ) Testicular prostheses advtg
- 35. Female Genital and Reproductive Tissues- uterus Cloacal exstrophy / intersex disorder Autologous rabbit uterine smooth muscle and epithelial cells Preconfigured uterine-shaped biodegradable polymer scaffolds
- 36. Vaginal reconstruction Engineered vaginal organs implanted into 4 pts with vaginal aplasia MRKHS Age 13-18 showed similar properties to those of normal vaginal tissue. Successful / no long term complications
- 37. Renal Structures Clinical problem ESRD One of the most difficult tissues to replicate in the laboratory. Application of regenerative medicine Cell therapy – clinical application still far away Bioengineering with ECM scaffolds .
- 38. Regenerative Medicine Approaches to Kidney Regeneration
- 39. Roadblocks Science • Neovascularisation /Nerve • scaffold • complexity Ethics • SC • Lack of RCTs
- 40. Future - Bioartificial kidney (BAK) Builds on concept of RAD Clinical trials on RAD The kidney project – goal Components
- 41. 3D bioprinting
- 42. Conclusion
Editor's Notes
- The term regenerative medicine is often used synonymously with tissue engineering the term was coined by willian haseltine ,In effect to bring all areas under one defining field
- Cells are obtained from individuals by biopsy Now these cells can be.. Autologous cells are preferred due to lack of immunogenicity
- Cells used can be… Somatic cells are differentiated cells Their main limitation
- Removal of an oocyte nucleus in culture, followed by its replacement with a nucleus derived from a somatic cell obtained from a patient. Their use have major limitations,
- These r obtained from specialised adult cells through a process called reprograming Reprogramming is a technique that involves de-differentiation of adult somatic cells to produce patient-specific pluripotent stem cells, eliminating the need to create embryos
- Celss are isolated from various tissue in body inclusing BM, adipose tissue
- MC USED coz it enjoys good protocol for MSC extraction High prolifration potential No risk of tumor formation Also have immunomodulatary func dur to production of various growth factors
- Obtained from umbilical blood sampling at the time of birth or by amniotiocentesis or CV samplingi n fetus Comp to adult stem cells
- They are constructs or support structures that are engineered to facilitates the growth of cells, delivery of cells to graft site in body and guide development of new tissue Majority of mammalian cell types are anchorage dependent and will die if not provided with a cell-adhesion substrate.
- Highly porous, high sa/volm Biocompt- minimal degree of inflamation Good bioactivity- biological molecules on surface thus promoting cell prolifration Must bioabsorbed in a controlled and appropriate time Adaptible to diff manufracturing tech
- Due to residual growth factors Advg of inherent bioogical activity and mechanical properties of natural ECM, most natural scaffolds comes from pigs- source of disease transmsn and these protein composn and structure is diffrnt from body itself BIOCOMPATIBILITY ISSUE Advg of synthetic – can produce organ structure of any shape in 3d space, can be quantified, have good reproducibility and low cost, many characteristics lile porosity can be controlled Natural – have natural essence – so more biocompatible and biodegradable Recently 3 d helps in creating highly complex structures with accurate design. They used hydrogels as scaffolds
- is that cells cannot be implanted in volumes exceeding 3 mm3. Nutrition and gas exchange are limited by this maximal diffusion distance. If cells were implanted in volumes exceeding 3 mm3, only the cells on the surface would survive, and the central cell core would undergo necrosis resulting from a lack of vascularity.
- These includes various growth factors, cell adhesive molecules like cadherin, selectin, integrin These bioactive factors are loaded along with cells in scaffold .they help in…., maintain cell viability, ohenotype and guide cell differentiation
- Overview of te in uro Ist cell types in uro
- Fig showing tissue engineered urinary tract wall Uro/ interstitial cell/sm/nn Bladder wall is reconstr with a cell seeded scaffold graft Early regeneration results 3 mths- all layers hist disturbance Final reconstruction outcome uc layer is well restored coz it has a high regeneration potential
- One of the advantages of this method over nongenital tissue grafts used for urethroplasty is that the material is “off the shelf.” eliminates the need of additional surgical procedures for graft harvesting, thus decrease operative time Decrease potential morbidity from the harvest procedure.
- Acellular grafts can only be used when healthy part of urethral wall is present, coz the tissue regeneration starts from its edges Mostly used BAM SIS Cell seeded grafts showed better results compared, here BM is seeded with UC or epiderml skin from foreskin
- Study by atala gp Autologous cells are taken by tissue biopsy. Cultures and seeded …. Pt are fu for long tern 71 mth avg
- Results showed that flow rate greatly improved in all 5 pts
- on urethrogra copmpared to preop images post op images showed patent and smooth urethra
- Here is another study on hypospadias repain using tegraft 6 pts of sever hyposadias taken- perineal and scrotal hypo with pronounced chordee Surgey was done in two stages …..uc werw harvested by bl and seeded on acellular dermal matrix Graft is uded in onlay fashion Fu 5yrs , 3 pts Concluded that treatment is feasible in selected gp of pts – pronounced chordee, shaotage of prepuce and penile skin and bladder extrophy pts
- So there is a search for novel technique for bladder replacement Since ub acts as temporary reservoir of urine ,.. It should compliant wall to prevent damage to ut, Urotheium that prevents absorption of toxins during urine storage
- results Only 30 of smooth muscle cell grows in graft – reslts are poor coz early exposure of scaffolds to urine causing in extreme fibrosis. this decreases elasticity of bladder Acellular collagen matrices can be enhanced with growth factors to improve bladder regeneration.
- Human urothelial and muscle cells can be expanded in vitro, seeded onto polymer scaffolds, and allowed to attach and form sheets of cells. The cell-polymer scaffold can then be implanted in vivo. Urothelium is associated with a high reparative capacity. Bladder muscle tissue is less likely to regenerate in a normal fashion
- Approaches are compared in an aninal model by.. Seeded 95 of original capacity and trilyered histology vs 46 capacity, minor cell ingrowth and fibrosis 22
- This a landmrk study by atala gp.. Which is first clical 9 pt of mm .. 2 lost to f/u… pt had poorly compliant bladder, failed parma treatmnt and were on cic
- He cocludes tht pt those had composte graft with ow had better post op compliaance but it is syill no analogous to gold std treatment dats ecp Study provides impt step in trasferring te in clinicl setting
- Phase 2 multicentric study done in Chindren with neurogenic bladder due to spina bifida On fu of 3 years So compared to previous studies this study doesn’t showed good results Cocludes that serious s/e surpassed the safety std
- Similar engineering techniques are now being used for patients with bladder cancer, who are having engineered urinary conduits implanted after cystectomy Stem cells derived from fat can be differentiated into smooth muscle for the conduits, thus avoiding native cells from bladder cancer patients Tengion gp they hv done animal trials showing acceptabl results.. Now its under phase 1 trial.
- MYOBLASTS ISOLATED FROM ABD WALL MUSCULATURE
- It has narrow lumen Tendency to collapse due to constatnt high abd pressure which makes engineered tissue prone for ischemia and scarring It is one of the reason why no phase 1 clinical trial has been done, only stdy r done in animals to comare scaffolds
- Various cell line has bn used to correct ed in animal models like cultured human corporeal smooth muscle cells may be used in conjunction with biodegradable polymers to create corpus cavernosum tissue de novo In another study, Chondrocytes isolated from human ear were seeded on rod-shaped biodegradable polymer scaffolds ….. human cartilage rods were engineered in vitro for potential use as penile prostheses. The engineered human cartilaginous rods were flexible, elastic, and able to withstand high degrees of compressive forces.
- Approach toward restoration of testic function canbe
- Used for subtotal uterine tissue replacement in animals
- Several disorders that require vaginal reconstruction, curretly ileal seg are used for vag recontr but its oftn ass with compl In this study 4 pt of vag aplasia taken Vulvar biopsy- Vgibal epithelial and sm cell tissue cultured /seeded/organ cnstructed in incubator Organ surgically implanted via perineal route
- Thhere is need for te renal units but.. complex organ unique structural and cellular heterogeneity Isolation of particular cell types that produce specific factors may be a good approach for selective cell therapies. cells that produce erythropoietin have been isolated in culture, and these cells could eventually be used to treat anemia that results from ESRD ‘’’’Extensive research is going on the use on scaffolds for bioeng of kidney.. And in animal studies accelular kidney matrices showed good results
- One of the big issue is not getting proprer nv although there is a lot about biopeptides, angiogenic factors, antibodies like cd31, using a good omental wrap is a good idea Also ingowth of neuronal networks is also an issue
- Goal is to miniaturise this extracorporeal RAD into sx implantable , self monitoring artificial kidney Hemofiltration tht made of silicon memb made by nanotechnology do ultrafiltrasion nd remove excessive toxin Renal cell bioreactor tht is lined with human tubuler cells made by tissue engineering tht perform metabolic func of kidney Relies on blodd pressure without need of pump nd power supply After a single sx it can contionusly process blood for 24hr per day
- Similar to 3d printing – plastic filaments Application- cardiac tissue, bioprtng a complex tissue like kidney has been difficult since it contain more than 20 unique cell types Limitation is ability of cell to survive printing process
- Te is an exciting field that has a potential to revolutionise the medicine te is abt to grow and about to 3 times of its present market size in next 10 years But desite the extensive research it still has a long way to go and made a meaningful transition in urology practice.