Future Flashcards

1
Q

The quality triology

A

Quality planning
- to plan and define the quality req.m of end product
Q control
- the variability in product and process attributes need to be controlled by scientific/ risk-based statistical tool for monitoring end product quality
Q improvement
- conti. process throughout product life cycle by regulating controls

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

5 steps of Quality by Design

A
  1. Define the quality target product profile (QTPP)
  2. Identify critical quality attributes CQA
  3. Identify critical material attributes CMAs and critical processing parameter CPPs
  4. Design space development
  5. Quality control strategy& continuous improvement
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

6 control strategy for quality improvement in QbD approach

A

1 Input materials testing
2 Release testing (specifications) on end product or real time release testing
3 Product characterisation
4 In process controls (inc in process materials testing)
5 Continuous process verification
6 Process characterisation and quality risk management/ assessment and justification of CQAs control and of quality risk control

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

the basic concept of tissue engineering

A
  1. cell isolation and purification of stem cells
  2. cell expansion in numbers (enough to make organ)
  3. seed on a suitable scaffold (3d structure), use gf to stimulate proliferation and differentiation
  4. maturation of tissue in Petri dishes in lab
  5. implantation in patient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

4 methods of cell isolation

A
  1. differential adhesion (certain cells bind to certain surface better than others)
  2. density centrifugation (isolate mono nucleus cells)
  3. FACS (fluorescence- activated cell sorting)
  4. MACS (magnetic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

3 methods of cell expansion

A
  1. stirred tank (3d envrionement)
  2. fluidised bed (pass culture medium through tube into the cells, fluidise the particles, skyscraper scale!)
  3. hollow fibre (bundle of 3d fibres for cell to grow on, packed in a small vol)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

7 characteristics of ideal 3d support (scaffold)

A
  1. biocompatible
  2. biodegradable
  3. cytocompatible (cell need to be able to stick on them)
  4. porous
  5. mechanically appropriate
  6. architecturally appropriate
  7. growth promoting - controlled release of gf
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

natural scaffold materials

A
  1. polypeptide eg collagen, gelatin, fibrin, laminin (ECM)

2. polysaccharides eg hyaluronic acid, alginate, chitosan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

synthetic polymer scaffold materials

A

polyesters are the most commonly used
eg PLGA - poly lactic co glycolic acid
made up of lactic acid and glycolic acid. can control degradation rate of scaffold. if more LA conc, then more hydrophobic, slower degradation vice versa
- bioceramics and bioactive glasses eg hydroxyapatite. for osteoblast growth into bones
- decellularised tissue (use donor tissue and remove cellular components so no rejection then grow pt cell on them)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

the advantages of having synthetic rather than natural polymers for scaffold

A

controlled parameters eg degradation rate, strength, chemical and mechanical functions, adhesion rate

  • reproducibility - scalibility
  • bulk processing
  • interesting properties eg temp responsive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

7 method of scaffold formation

A
  1. compression
  2. solvent casting (liquid pour into mould)
  3. particle leaching
  4. freeze drying
  5. spinning
  6. electrospinning
  7. 3d printing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

scaffold provides 3d environment for cells to grow - much better results than one plane growth. what are the two 3d scaffold that’s commonly used

A

hydrogel

nanofiber - cells within nanofiber interact with signals by neighbouring cells as well as by the fiber

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

which arrangement of scaffold fibre can produce longer length of myotube?

A

aligned not random

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how does the geometric cue e.g. stiffness, patterning of scaffold affect (stem cells for) bone cell growth

A

the more drilled holes and more random (disorder) the arrangement of fibre surface, the more likely for osteopontin and osteocalcin to grow into bone tissue. muscle tissue is the opposite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

one of probs with synthetic material of scaffold is that they are not particularly cell adhesive or growth promoting. 2 methods to resolve this are

A

1/ blend solution - blend sol of polymer with agents that is adhesive to cells (or blend directly w cells eg laminin), eg collagen. then form scaffold
2. chemical plasma and wet chemical treatment, give scaffold functional groups that cells like to attach to. covalently attach to proteins, eg.make amide bonds through carbo acid and amine fucntional groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

3 key ECM adhesive peptides sequences used to improve the adhesivity of scaffold eg PEG hydrogel scaffold

A

1 add RGD (arg-gly-asp) to promote ingtegrin receptor interactions with cell surface improve adhesion
2 YIGSR Tyr-Ile-Gly-Ser-Arg- lamini ECM
3 IKVAV Ile-Lys-Val-Ala-Val- lamini, nerve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

we can modify scaffold to improve its ability of attaching to laminin so better formation of nerve tissue. what are the 3 ways? which gives the best nerve tissue growth results?

A

1/ colavent coupling of laminin by adding COOH groups onto nanofiber material
2/ physical adsorption of laminin onto nanofiber mat
3/ electrospun blended laminin polymer nanofiber mat
blended

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

compare static vs perfused bioreactor in bone defect repair

A

Bioreactor culture increased cell proliferation and bone matrix formation in comparison to static
-Patient-specific bone constructs a possibility using this technique (ct scan of pt bone structure, design scaffold then use pt own msc to grow)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

is body a bioreactor? how does this method work for bone growth?

A

yes. body has the correct environment for tissue development eg chemical signalling, sheer forces.
- you inject alginate hydrogel into space bw periosteum and bone to activate stem cells cause proliferation and migration of cells into the gel matrix to form new bones
- use cell-free scarffold to stimulate repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

is acellular strategies better than engineered cellular repair?

A

yes - can be designed to release cocktails of small and macromolecular drugs and to recruit specific cells (avoid isolation and enrichment etc)
optimum envrionemtn for tissue growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

the challenge of rebuilding capillary bed is the complexity in the vascularisation and the fine size of the each vessel. what are the 3 solutions

A
  1. seed scaffold with endothelial cells RANDOMLY.
  2. incorporate VEGF into scaffold, implant into pt and attract pt own endo cells hope to make the right cap
  3. build scaffold from donor around vascular bed ex vivo (in-vitro)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

which component of blood contains important proteins eg GF for blood vessel formation?

A

platelets contains VEGF. PDGF

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what the endothelial progenitor cells in our blood that can form blood vessels when stimulated?

A

endothelial colony forming cells ECFCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what are the steps to produce a capillary vasculature

A
  1. centrifugation of blood to obtain plasma
  2. plasma rich in GF that can form capillary bed
  3. signification of plasma to form human platelet lysate
  4. HPL is a sol full of GF and fibrin
  5. add endothelial progenitor cells -endothelial colony forming cells ECFC into lysate
  6. maturation
  7. formation of bv
  8. GF stimulate pt’s existing vessel to integrate w new bv
  9. pt’s own endo cells, so no rejection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
newt can regenerate lost limb, how can mammal regenerate tissue with the help of pharmacological treatments?
myoseverin can de-differentiate human muscle into mononuclear myoblast cells - add reversine to proliferate and send cells to a even earlier more plastic state where they have more potential to diff (can diff into fat, muscle, bone - multipotent) - cells fuse together then re-differentiate
26
what does quiescent mean for stem cells?
losing the ability to be activated, proliferate, differentiate and repair
27
what is quiescent state (of stem cell) in term of signalling molecules present and how can we re-activate those cells
quiescent is an inflammatory state, where you can find inflammatory markers signalling in niche, preventing neural stem cells to activated and repair. - if inhibit the inflammatory markers in stem cell niche of old animal, then we can make them act as if they were young stem cell.
28
how to bioprint a heart?
1. MRI for human heart histology and blood sample collected from pt 2. blood cell converted to iHPSC 3. cell differentiation into cardiomyocytes 4. bio-ink hydrogel. cells combined w nutrients in a liquid hydrogel envrionemtn to keep them alive 5. 3d bioprinter cartridges are those hydrogel w viable cells 6. printing one layer at a time guided by MRI 3D shape 7. put heart into bioreactor that mimic the nutrient and o2 conditions inside human body 8. cells w fuse into network form living tissue, HEART BEAT 9. scaffold dissolve leave only heart in bioreactor
29
what is the kaizen (6 sigma process)
Kaizen is a continuous process which involves repeatedly making small improvements to the product and production process to ensure that the quality standards are always improving.
30
name the 5 types of bioreactors
``` stirred tank rotary cell culture NASA compression tension perfusion ```
31
challenges of tissue engineering
- Stem cell differentiation - Vascularisation (leaf scaffold?) - Anastomosis (connect between tubes, fibers) - Innervation (to supply with nerves) - Synaptogenesis - Arrangement of multiple cell types in complex 3D structure (bioprinting, layer by layer) - Regeneration
32
challenges of 3D bioprinting
1. cell density 2. resolution 3. vascularisation 4. innervation 5. mechanical integrity
33
what does it mean by planning quality target product profile (QTPP)
plan the quality characteristics of target FINAL product before development even begins. this primarily involve vital final product features that need to be monitored throughout product development features inc IN VIVO targeted performance/behaviour eg dissolution, dose, appearance, content uniformity, hardness. what is important to PATIENT
34
what are step 2: Critical Quality Attributes (CQAs), and how they link to QTPP
CQA are indicators of product quality performance which directly relate to QTPP. for each process step, an intermediate CQA need to be identified, this may impact the CQA of the final product (drug) = QTPP
35
what does Step 3: Identification of critical material attributes (CMAs) and processing parameters (CPPs) help you achieve in manufacturing drug? how are they linked to CQA?
understanding of the material (API, excipient, device) and the process steps, which in turn aid product understanding. - ensure consistency and control of product quality - a continuous, marginal gain approach - combination of CMA and CPP can determine and control the CQA in the final product
36
the purpose of Step 4: Design Space Development
- allow to explore the relationship bw material, process inputs and CQAs - allow manufacturers to show regulatory bodies 'a comprehensive understanding of their processes' - reg bodies approve a design space within an acceptable operational range (for CQAs) - allow companies flexibility to operate within the range w/o frequent submission of revised info to reg bodies.
37
describe the flow of manufacturing process from CPP and CMA
1. CPPs and CMAs to QRM (quality risk mgn) 2. QRM to DoE (design of experiments) 3. DoE to QbD 4. QbD back to CPPs and CMAs
38
in QbD, what does company's quality control strategy allow them to achieve?
quality control strategy enable continuous improvement
39
what are control strategies (QbD)
a planned set of controls, derived from currently product and process understanding that assures process performance and product quality
40
two example of the controls you can have in control strategy
- in process measurement | - end product testing
41
7 Benefits of introducing QbD | DCCT FML
1 reduce develop.m time 2 minimised product cost by multiple times (not individual designed process) 3 helps in effective troubleshooting 4 facilitates timely launch of product 5 increase consumer generic acceptance 6 monitors regulatory oversight (failure) with greater flexibility 7 maintains product life cycle with greater ease
42
What is Quality by Design (QbD)?
- align w kaizen principles - aim to deliver products w target quality by planning not by chance - building quality into the product by design, avoid quality by testing (traditional) - enable conti. improvement and achieve operational excellence
43
describe a typical batch manufacturing process, how long does process take
in region 1: synthesis and crystallisation ship to region 2: blending, granulation and sizing, tablet press& coating takes months
44
Advantages of Continuous Manufacturing (CM)?
1 integrated process with fewer steps (no shipping): - shorter processing times (all steps undertake at same place) - increased efficiency - no manual handling, increase safety 2 smaller equipment and facilities - more flexible operation - reduced inventory level - lower capital costs, less work-in-progress materials. smaller ecological footprint 3 on-line monitoring and controls strategies needed for increased product quality assurance in real-time - real time release testing provide consistent quality 4 significant reduction in COST 5 the science exists to enable CM of pharmaceuticals 6 no regulatory hurdles for implementing CM (no need to define batch size) 7 CM consistent with FDAs QbD effort - more modern Manu approach - potential to improve QA and drug consistency - enable quality to be directly built into process design
45
describe what a hybrid manufacturing process
it is a system consists of two separate 'multiple disconnected batch steps': 1 from chemical to API (manufactured in Free Trade Zones around the globe) 2 from API to tablets
46
what are FTZ and what benefit does it provide to Pharma companies
free trade zones around the globe. allow companies to import and export goods w/o customs , excise duties/ good and service tax (GST)
47
what are the first two drugs switched from batch to CM process
vertex's orkambitm (ivacaftor)- for CF | Prezista (darunavir) for HIV
48
current challenges for hybrid manufacturing
- need for integration of analytical tool (NIR Near Infrared for blend uniformity) to control system, support feedback, feed-forward control - need data mgt tools - define representative sampling to consistently assure product quality eg location of sampling probes and sample size/frequency - need for enhanced process understanding eg
49
state of control requirement for CM is dependent on...?
state of control depends on the control strategy implementation
50
3 levels of state of control for CM
level 3 - low detectability for addressing natural variance in CM w/o sig end product testing level 2 - operation within estb. ranges (multivariate) and confirmed w final testing (flexible CMA&CPP within design space) level 1 - active control sys w real time monitoring of process variables/CQAs, flexible CPPs to respond variability in CMAs
51
what's the key aims of control strategies in CM
- to monitor in process variability | - to detect disturbances in real time
52
the advantages of Portable continuous, miniature and modular (PCMM) manufacturing
1 small footprint 2 highly flexible 3 use an integrated process control system 4 designed for multiple products allow rapid changeover flexible batch size production-on-demand
53
what are stem cells
unspecialised cells that can self renew produce more stem cells differentiate into other cell types
54
process of inducing a somatic cell into iPSC
transfection of fibroblast w/ combination of 24 genes known to be important in ESCs. SOX2 OCT4 NANOG
55
stem cells have a number of transcription factors and cell surface markers, what methods are used to determine this expression?
western blotting RT-PCR immunocytochemistry (ab) flow cytometry
56
3 types of PSC (embryonic)
- endoderm (lung) - mesoderm (heart, RBC) - ectoderm (skin, neuron)
57
how many days does it take for ESC to mature in the embryo?
day 1 zygote | day 5 blastocysts
58
what is directed differentiation , eg?
- use the mechanical properties of cell growth surface to direct stem cell differentiation - eg stem cell on hydrogel surfaces w/ different elasticities - 10-25kpa surface support self-renewal - neurone cells prefer soft gel
59
what determines whether our immune system see cells as self or non-self
human leukocyte antigen complex HLA
60
are HLA inherited
yes, as haplotypes (half from mum/dad)
61
are hPSCs hypoimmunogenic due to its undifferentiated state?
no, hPSC express HLA class 1 antigen, but not class II
62
how to make iPSC hypoimmunogenic?
use CRISPR cas9 knock off HLA class 1+2 (gene at 2 loci), use lentivirus to deliver CD47- a tumour antigen provides shielding effect and avoid phagocytosis
63
PSC has teratoma risk?
yes