Stem Cell, tissue engineering and its applications in Otorhinolaryngology

1. STEM CELLS, TISSUE
ENGINEERING AND APPLICATIONS
IN OTORHINOLARYNGOLOGY
Presenter
Dr Chunu Darnal
Resident, ORL&HNS
Bir Hospital, NAMS
Kathmandu, Nepal

2. Introduction
 What is cell?
 Latin word “cella’ meaning
"small room”
 Smallest , basic structural,
functional, and biological
unit of all known
organisms.
 What are
tissues?

3. Cell cycle phases
 G1: enzymes, nucleic acids
 S: DNA
replication/synthesis
 G2: cell growth and
duplication
 M: replication
 G0: resting state

4. Types of cells according to ability of
cell proliferation
 Labile cells: skin
epithelium, mucosal lining
of GIT, haematopoietic
cells
 Quiescent cells: hepatic,
kidney, pancreas
 Permanent cells: nerve
cells, skeletal, cardiac
muscle cells

5. Introduction
Stem cells
 An unspecialised cells of
human body
 Ability to differentiate
into any type of cell of an
organism and have the
ability of self renewal
 Exists in both embryos
and adult cells (somatic)

6. Stem cells : unique properties
 Capable of dividing and renewing themselves for
long periods
 “Unspecialized’ and can give rise to specialized
cell types, differentiation specificity determined by
environmental signals
 “Uncommitted’ until it receives a signal to develop
into a specialized cell

7. Introduction : History of Stem
cells
 1956 : 1st successful bone marrow transplant performed by Dr
E. Donnall Thomas in Cooperstown, New York among
identical twins for leukaemia.
 1960 : key properties of a stem cell 1st defined by Ernest
McCulloch and James Till
 1981: Mouse beginnings
Martin Evans of Cardiff University, UK at the University of
Cambridge, first identified embryonic stem cells in mice.

8. History of stem cells
 1997: Dolly the sheep was
unveiled by Ian Wilmut and
his colleagues at the Roslin
Institute, Edinburgh as the
first artificial animal clone.
 Human cloning : ethical
issues

9. History of Stem cells
 1998: James Thomson
(University Of Wisconsin
Madison) isolated cells
from the inner cell mass of
the blastocyst, and
developed the 1st human
embryonic stem cell line in
culture.
 1998: Johns Hopkins
University derived human
embryonic cells from fetal
gonadal tissue.

10. Evolution of concept of stem
cells therapy
Studies showing
particular cell surface
markers in
haematopoietic
system-clonogenic in
vitro
Have ability to
completely restore the
haematopoietic system
in mice whose bone
marrow destroyed by
irradiation
Such properties later
on identified in most
normal and malignant
tissues as
adult/somatic stem
cells

11. Introduction :stem cells
According to potency of stem cells
 Totipotent cells : zygote
 Pluripotent cells: embryonic stem cells-blastocyst
 Multipotent cells: haematopoietic cells
 Oligopotent cells: myeloid stem cells
 Unipotent cells: dermatocytes

12. Stem cells

13. Stem cells

14. Embryonic stem cells
 Derived from the
undifferentiated inner mass
cells of a human embryo
 Pluripotent

15. Embryonic stem cells
 Can provide unlimited source of relevantly
differentiated cells
 Issues:
 Ethical background as generated by destruction of
living human blastocyst
 As histocompatibility antigens expressed by cells,
immunologically may be compatible to restricted
immune privileged sites

16. Somatic/adult stem cells
 Undifferentiated cells,
throughout the body that divide
to replenish dying cells and
regenerate damaged tissues.
 Examples:
 Bone marrow
 Neural tissues
 Haematopoietic cells
 Skin-keratinocytes

17. Somatic stem cells
Advantages
 Readily expanded in vitro, usually maintaining stable
differentiation pattern
 Can be expanded from autologous tissue, initiate no immune
rejection
Examples
 Transplantation of donor haematopoietic stem cells for
treatment of leukaemia
 Epithelial cells for treatment of burns or repair corneal
damage
 Neural stem cells grafting for treatment of spinal cord injuries

18. Induced pluripotent stem cells
(iPSCs)
 Study of Embryonal cells
led to identification of
genes associated with
maintainence of stemness
 Induced expression of stem
cell genes Oct4,Sox2, c
Myc and Klf4 in
differentiated cells
 Thus, artificially generated
from somatic cells and
function similarly to PSCs

19. Induced pluripotent stem
cells(iPSCs)
 Ability to regenerate a wide
range of tissue types
 Can be generated from
autologous adult tissues
thus a matter of research
for clinical use in
genetically defective or
damaged tissues
 Concerns: potential
carcinogenic effects of
genetic alterations

20. Mesenchymal stem cells
 Multipotent stem cells identified and isolated from adult and
foetal tissues like; bone marrow, umbilical cord, dental pulp
 Good expansion and differentiation potentials, immune
modulatory properties
 Usually differentiated: osteoblasts, chondrocytes
 Non-mesenchymal differentiation: neurons, hepatocytes
 Clinical interest: autologous transplant

21. Mesenchymal stem cells

22. Tissue engineering
 Methods for generation of tissues and organs from
cells
 Assembling the differentiated cells into functional
tissues and organs
 Fundamental premise : regeneration of tissues
and restoration of function of organs through
implantation of cells/tissues outside the body or
stimulating cells to grow into an implanted matrix

23. Tissue engineering-
fundamentals
Cells: stem cells
differentiated
Source: autologous,
heterologous
Bioactive factors:
Cytokines, growth
factors, hormones,
morphogenetic
proteins
Scaffolds
Biologic: trachea,
dermis, intestine
Synthetic: ceramics,
composites, metals,
polymers

24. Tissue engineering

25. Tissue engineering : Scaffolds
 Where the cells are
seeded prior to
implantation
Types of scaffolds
materials
 Natural : collagen,
glycosaminoglycans,
alginates
 Synthetic : polymers,
metals, glasses and
ceramics, composites

26. Tissue engineering : scaffolds
Characteristics
 High porosity
 High surface area
 Structural strength
 Specific 3D shape
 Biodegradability

27. Advantages of tissue
engineering
 Tissues can be designed to grow in such a way that precisely
match the requirements interms of :
 Size
 Shape
 Immunologic compatibility
 Minimising further treatment
 Both non-stem and stem cells can be used for tissue repair
and regeneration

28. Therapeutic uses of Scaffolds in
Otorhinolaryngology
 Manufacture of sutures
 Hemostatic agents
 Blood vessels (collagen tubes)
 Dermal regeneration for burns treatment
 Peripheral nerve regeneration

29. Therapeutic uses of stem
cells
 Regeneration of tissues e.g. cartilage, adult teeth,
skin, cochlear hair cells, dopaminergic cells in
Parkinson’s disease
 Organ replacement e.g. bone marrow transplant in
leukaemia
 Treat genetic disorders e.g. congenital immune
system disorders, anemias

30. Applications in
Otorhinolaryngology
Ear and nose
 Studies on regenerative stem
cells to rectify common
structural or functional
problems of nose and ear
 Alternative approach to
produce cartilage using
scaffolds using autologous
stem cells
 Reported ear biopsies, rib
tissues successfully used for
nasal reconstruction
 Augmented repair of chronic
TM perforation with use of
growth factors
Fig: Fat stem cells for treatment
of skin necrosis

31. Applications in
Otorhinolarngology
Cochlear damage or
degeneration
 Various studies on
application of stem cells for
sensorineural hearing loss
 Resulting from inner ear
cochlear dysfunction
involving loss of inner hair
cells

32. Application of stem cells-
Sensorineural hearing loss
 Kelvin Y. Kwan/Rutgers
University-New Brunswick
2017, A stem cell-derived
neuron grafted onto a
mouse cochlea in the inner
ear that lacked neurons
 Taken as a double sword
due to risk of cancer

33. Progenitor Cell Therapy for Sensorineural
Hearing Loss in Infants, Linda et al
(September 2019)
 Phase 1 trial done with umbilical cord blood therapy for acquired
SNHL in children
 11 children less than 6 years of age, with severe to profound
non-genetic SNHL, were evaluated before treatment and 1, 6 ,
and 12-months post treatment.
 No significant adverse events occurred during the study.
 Improvements in both ABR thresholds and CN VIII latency were
evident at 1-month follow-up testing and throughout the 12-
month study period.
 10 subjects experienced an expected improvement of speech
language pathology test scores over the course of the trial.

34. Development?
 Rinri Therapeutics was
spun out of the University
of Sheffield in 2018
 Aim of developing a stem
cell therapy for auditory
neuropathy.
 Grows embryonic stem
cells into auditory nerve
cells and injects these cells
into the ear, where they are
designed to replace the
damaged hair cells

35. Development ?
 Rinri’s stem cell therapy
could be the first treatment
to regenerate inner ear
cells.
 This technology has
already improved the
hearing of gerbils in a 2012
study published in Nature.
 Aims to test the therapy in
humans within the next
three years.
“The regenerative
capacity of inner ear
hair cells and
neurons is zero. You
can’t regenerate the
complement of cells
you’re given at birth”

36. Applications in
Otorhinolaryngology
The trachea
 5 year successful clinical
results using tissue
engineering strategy
 Bioreactor growth of a
decellularised donor
human trachea repopulated
with cultured autologous
stem cells
 Polymeric scaffolds been
transplanted successfully
as airway replacement
after cancer surgery

37. Applications in
Otorhinolaryngology
Larynx and vocal cords
 Cell free scaffolds of collagen, hyaluronic acid or
fibrin enhance laryngeal wound healing
 MSCs enhance vocal cord remodelling and reduce
scarring
 Takes upto 6 months and doubtful about the
persistence

38. Treatment of vocal fold scarring with autologous bone marrow-
derived human mesenchymal stromal cells—first phase I/II
human clinical study, Stellan et al, 20th March 2020
 In this open-label phase I/II study, 16 patients with scarred
VFs with severe voice problems were treated with surgical
scar resection followed by local injection of autologous MSCs
into VF.
 Patients were monitored 1 year for serious adverse events or
minor complications.
 Vibration and elasticity were improved in approximately 2/3rd
of treated patients.
 May offer a safe and feasible therapeutic option.

39. Treatment of vocal fold
scarring……………..

40. Applications…….
 Muscle derived MSCs in
peripheral nerve damage-
facial and recurrent
laryngeal nerve
 Deficiencies of
maxillofacial skeleton
 Autologous stem cells -
olfactory ensheathing cells
assist neural and other
regenerative procedures
Stem cell therapy for
nerve injury, Sara
Sayad et al (2017)
MSCs such as embryonic
stem cells, bone marrow
MSCs, adipose-derived
stem cells, etc. have been
studied and the existence of
beneficial effects on nerve
regeneration after injury has
been confirmed.

41. Cancer stem cells(CSCs)
 Dysregulated signalling pathways (e.g. Notch,
Wnt, Sonic hedgehog) lead to shift of CSCs
divisions towards greater self renewal, increasing
the number and thus loss of tumor growth control
 CSCs been identified in both HNSCC and non
HNSCCs
 Tobacco, alcohol, HPV act to increase the stem
cells and alter the behaviour

42. Cancer stem cells (CSCs)
 Many solid tumors respond
poorly to current therapies
and only about 50% of
HNSCC patients survive
longer than 5 years from
diagnosis
 CSCs responsible for
tumor growth and
metastasis
 Thus, therapy to be
targeted towards the
CSCs for successful
elimination.

43. Stem cell therapy in Nepal
 The Binayatara Foundation partnered with the
University of Illinois at Chicago and the Civil
Service Hospital of Nepal to support development
of country’s first bone marrow transplant (BMT)
center
 First successful transplant completed in August
2016
 Similarly, fat stem cells graft been used widely at
various skin clinics in Nepal for hair loss

44. Challenges in Nepal for stem
cells therapy and tissue
engineering Lack of trained/qualified personnel
 Poor economic status, cost and quality which
subdues the use of stem cells as regenerative
therapy for treatment of diseases
 Lack of highly sophisticated laboratory set and
costly materials including reagents, media,
and sophisticated equipments

45. Challenges in Nepal…..
 Lack of government guidelines for the stem cell use and
legal support
 Lack of international collaboration support strategies
 No adequate knowledge about stem cell therapy due to
people’s belief in primitive therapy and traditional cultural
issues.

46. References
1. Scott brown’s Otorhinolaryngology Head and Neck Surgery
volume 1, 8th edition
2. Scott brown’s Otorhinolaryngology Head and Neck Surgery
volume 1, 7th edition
3. Cummings otolaryngology volume II, 6th edition
4. Stem cells: past, present, and future, Wojciech Zakrzewski et al
5. Tissue Engineering for Otorhinolaryngology Head and Neck
Surgery, David G. Lott et al
6. Progenitor Cell Therapy for Sensorineural Hearing Loss in Infants,
Linda Baumgartner et al
7. Stem Cell Therapy in Nepal: Challenges and Opportunities,
Bhuvan et al
8. Stem cell therapy for nerve injury, Sara Sayad et al
9. Treatment of vocal fold scarring with autologous bone marrow-
derived human mesenchymal stromal cells—first phase I/II human
clinical study, Stellan et al.

47. THANK YOU