Stem Cells in Dentistry Flashcards
define + examples totipotent
capable of giving origin to new individual (eg fertilised egg and first 4 cells produced by its division)
define + examples pluripotent
can differentiate in to almost all types of adult cell types but NOT foetal/ adult animal (eg empbryonic stem cells, neural crest cells)
define + examples multipotent
gives rise to more than 1 type of specialised cell eg adult mesenchymal stem cells
define + examples oligopotent
differentiate in to a few cell types ig myeloid stem cells
define + examples unipotent
differentiate in to a single cell type eg skin cells
4 major groups of stem cells
EFAI:
- embryonic (ES)
- foetal tissue/ umbilical cord
- adult (stomatic) stem cells
- induced pluripotent (iPS, synthetic)
3 types of adult stem cells
- haemopoietic (in blood)
- mesenchymal (MSCs, derived from bone marrow BMMSCs)
- MSCs from dental tissues (derived from neural crest cells –> diff uses to other MSCs)
properties of stem cells
Stem Cells Definietely Don’t Make Things Easy:
- Self-renewal
- Clonogenicity
- Daughter cells
- Differentiate in adult organism (bc they are immature and unspecialised)
- Markers (express verifies stem cell markers)
- Transplantable from one area –> grow in to a different type of tissue
- Experimentally induced to differentiate in to various cell lineages
5 types of dental stem cells
- Dental Pulp Stem Cells (DPSCs)
- Stem cells from Human Exfoliated Decidious teeth (SHED)
- Periodontal Ligament Stem Cells (PDLSCs)
- Dental Follicle Stem/Progenitor Cells (DFSCs/ DFPCs)
- Stem Cells from the Apical Papilla (SCAP)
sources of dental stem cells
dental pulp, eg exfoliated decidious teeth, extracted teeth (esp wisdom teeth) all pulp can be used as dental stem cells but it is unethical to use when in vivo
applications for dental stem cells BIC MEG
BIC MEG
- Bio teeth (engineering new teeth)
- Implantology (bone formation)
- Craniofacial regeneration
- Medical (eg tx of liver disease, muscular dystrophy, stroke, diabetes, spinal cord regeneration, cardiac repair
- Endodontics (pulp regeneration)
- Guided tissue regeneration (periodontal regeneration)
main function of Dental Pulp Stem Cells (DPSCs)
tertiary dentine formation during tissue injury/ repair
experimental findings of DPSCs
- odontoblast-like cells –> sialophosphoprotein –> dentine tubules
- forms pulp-dentine complex when it has HA (in mice)
- in vitro –> fat, nerves, cartilage, muscle
what are DPSCs NOT good at
making bone (osteogenic potential)
experimental findings of -Stem cells from Human Exfoliated Decidious teeth (SHED)
- in vitro –> bone, fat, nerves, muscle, cartilage
- can repair skull defects (in mice)
what are SHEDs NOT good at
dentine-pulp complex in vivo
experimental findings of Periodontal Ligament Stem Cells (PDLSCs)
–> bone, cementum, fat, cartilage, nerves, fibroblasts
what is the apical papilla
soft tissues at apices of developing teeth
what stem cells are found in
a. perivascular
b. perineural sheath
regions
a. perivascular: DPSCs, PDLSCs, SCAP
b. perineural sheath: DPSCs
problems with isolation of stem cells
- lack of specific markers
- not clear where stem cells reside/ able to retain potency
- large numbers needed for cell replacement therapies –> in vitro expansion required
define tissue engineering
tissues and organs regenerated by stem cell transplantation with/without scaffold to reconstruct and restore function of damaged/ diseased organs/ tissues
define organ replacement therapy
3D cell manipulation in vitro –> bioengineered, fully functioning organ to replace dysfunctional organ
4 thngs needed for stem cell therapy
SSSG
- stem cells
- signalling molecules
- scaffold
- growth factors
explain ‘scaffold’ and eg
base on which stem cells proliferate.
biodegradable material that can be synthetic polymer or processed biological products eg collagen
5 current treatment options for perio
-disease control intervention (eg RSD)
-bone/ HA grafts
-guided tissue regeneration using barrier membranes
-Growth factors / host modulating agents
(in development: PDLSCs)
5 factors for successful regeneration of periodontium
BASEC
- alvolar Bone restored
- Acellular cementum
- Sharpey fibres must insert in to acellular cementum and alveolar bone
- Epithelial seal must form to prevent migration of epithelial cells in to the defect
- gingival Connective tissue
method of using stem cells for periodontal redevelopment
- isolate PDLSCs
- expand PDLSCs
- transplant PDLSCs in to animal models with surgically-created periodontal defects
carrier used in PDLSC periodontal redevelopment
HA/ tricalcium phosphate (TCP)
what structures are re-formed using PDLSC periodontal redevelopment
PDL, cementum
stem cells used for dentine/ pulp regeneration
DPSCs, SHED
why are dentine/ pulp regeneration considered together
dentine regeneration relies on vital pulp
what is needed as well as stem cells in dentine/ pulp regeneration
BMP2
problem with dentine/ pulp regeneration
re-vascularisation
when would dentine/ pulp regeneration be used
endodontic disease
method of dentine/ pulp regeneration
self-assembling peptide hydrogel poured in to pulp chamber –> slef-polymerises under physiological conditons –> solid gel capable of supporting cell growth and differentiation
stem cell types used for
a. periodontal disease
b. caries/ pulp injury
c. tooth regeneration
d. root regeneration
a. periodontal disease: PDLSCs, DFPCs
b. caries/ pulp injury: DPSCs, SHED, SCAP
c. tooth regeneration: DPSCs, SHED, SCAP
d. root regeneration: SCAPs (dentine), PDLSCs (PDL)
how does root regeneration work
metal implant:
- HA/ TCP carrier with SCAP –> root dentine
- gelfoam carrier with PDLSCs –> PDL
method of whole tooth regeneration (also see pics)
epithelial + mesenchymal cells –> bioengineered tooth germ –> transplantation of tooth germ–> eruption
method of whole tooth replacement
epithelial + mesenchymal cells –> bioengineered tooth germ –> bioengineered tooth unit (mature tooth + periodontal tissue) –> transplantation of tooth unit –> bone/ surrounding structures heal around tooth unit
main difference between current bioengineered teeth and real teeth
bioengineered teeth are smaller
problem of ex vivo expanded cells
controlling/ preventing transformation
