Lecture 12 - Regenerative & Biological Therapy Flashcards by Bianca Zayas

What is regenerative medicine?

Branch of translational research which deals with the process of replacing, engineering, or regenerating human cells, tissues, or organs to restore normal function.

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Do products currently available in veterinary medicine actually “regenerate” tissue during healing?

Usually, no.

Remains unclear or unproven in many applications.

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What are most currently available regenerative therapies aimed at?

Reducing inflammation
Promoting neovascularization
Modulating and promoting an anabolic local environment during healing.

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What are currently available regenerative therapies NOT aimed at?

Direct regeneration of tissue via direct inoculation of a stem cell.

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What is a better term than “regenerative therapies” for the therapies that are currently available?

biological therapies

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Predominant indication in small and large animal medicine is the treatment of _____.

musculoskeletal disease

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What 2 aspects of musculoskeletal disease are biological therapies most used for?

Joint/osteoarthritis
Tendon and ligament injury

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What additional areas have ongoing research in veterinary medicine?

Pulmonary repair
Oncology and cancer therapy
Dermatology

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What does IRAP mean/stand for?

Autologous Conditioned Serum

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What does PRP stand for?

Platelet Rich Plasma

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What does “pro-stride” mean?

Autologous Protein Solution

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What are 4 locations from where we can get stem cells?

Bone marrow aspirate concentrate
Bone marrow-derived MSCs
Fat/Vascular Stromal Fraction MSCs
Autologous vs. Allogenic

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What is autologous conditioned serum (IRAP) widely used for?

Equine sports medicine (for the last 15-20 years)

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What does IRAP mainly use in its MOA?

Cytokines

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What are cytokines and what are the 2 general types?

Proteins within mammals that are secreted by various cells of the immune system that influence an effect on another cell.

Types = Pro-inflammatory and Anti-inflammatory

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What is the most common and central pro-inflammatory cytokine?

IL-1

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How is IL-1 involved in osteoarthritis?

It is upregulated in the joint and increases proteolytic enzymes (matrix metalloproteinases) which degrade type-2 collagen in articular cartilage.

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What is one anti-inflammatory cytokine involved in IRAP and what is another name for it?

IL1-ra; AKA IRAP protein

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Where does IL1-ra originate from?

monocyte cells in the blood

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What does IL1-ra bind to and why?

Binds to IL-1 receptors to block cellular signaling of inflammation.

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What does IL1-ra circulating in the blood do?

Normal amounts of circulating IL1-ra helps provide balance between anabolic (build/restore) and catabolic (breakdown) processes in the body.

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IRAP binds to _____, preventing _____ binding which would cause _____.

IL-1 receptors, IL-1, inflammation

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How do we capitalize on IL1-ra as a biological therapy?

Collect whole blood from animal. expose it to select surfaces to stimulate monocytes to secrete IL1-ra.

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How can blood monocytes be stimulated to secrete IL1-ra?

Borosilicate or chromium sulfate glass beads in a syringe
Held at body temp (37.5 deg C) for up to 24 hours
Centrifuged and serum aspirated off

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How much more IL1-ra vs. IL-1 does manipulated serum have at 24 hours (i.e. what is the IL1-ra to IL-1 ratio)?

6-10x more IL1-ra vs. IL1

How can autologous conditioned serum be used to influence inflammation?

It can be aseptically injected back into a joint compartment.

How often are autologous conditioned serum injections repeated?

Every 2 weeks for 3-4 treatments

What can be done with leftover IRAP serum?

Can be frozen for future use

Platelets are most commonly associated with _____ and \_\_\_\_\_. They are also a rich source of \_\_\_\_\_.

clotting, hemostasis, growth factors

What are growth factors?

Proteins that stimulate growth, proliferation, healing, or cellular differentiation in cells.

What do platelets contain within their cellular architecture?

alpha granules

What are alpha granules?

Storage centers for growth factors

What are some examples of sub-types of common growth factors?

1. **PDGF** (platelet-derived growth factor) 2. **TBF-β** (transforming growth factor beta) 3. **VEGF** (vascular endothelial growth factor) 4. **IGF-1** (insulin -like growth factor) 5. **EGF** (epidermal growth factor)

What 3 things do all growth factors have a global role in promoting?

1. Cell migration, proliferation, differentiation 2. Angiogenesis/neovascularization 3. Matrix/scaffold synthesis for tissue ingrowth

What is platelet-rich plasma?

A blood-derived therapy that focuses on enriching the plasma substrate from whole blood with growth factors released from platelets.

What are the 2 different methods of preocessing of PRP and which one is more common?

1. Centrifuge based (**more common**) 2. Filtration based

What are the steps to making PRP?

1. Collect whole blood mixed with an anti-coagulant 2. Initial centrifugation spin - separates RBC from buffy coat and plasma 3. Second centrifugation spin - separates platelets from majority of plasma

Most PRP kits result in _____ platelets per ml.

\>1000 x 10³

What do some PRP kits use to stimulate release of growth factors from alpha granules?

Calcium chloride or bovine thrombin

How is PRP used in the patient?

Injected into the site of injury

What can we do with unused PRP?

Freeze it and thaw at future use

In large animal (equine), PRP is predominantly used for \_\_\_\_\_.

soft tissue injury

What are some specific examples of uses for PRP in equines?

Tendon or ligament sprain/complete tear of fibers

PRP is often injected under _____ guidance.

ultrasound

What is the predominant use for PRP in dogs?

Intra-articular injection in management of osteoarthritis

What is the market name for autologous protein solution?

Pro-stride

What is autologous protein solution?

Combo of PRP and ACS

The first step in processing APS is identical to \_\_\_\_\_.

PRP

What does the 2nd processing step of APS do? What does it do for veterinarians?

Upregulates IL1-ra without the need to incubate serum; Makes APS therapy more "point of care" for vets

What are stem cells?

Biological cells that differentiate into other types of cells.

Stem cells can also divide to produce more of the _____ of stem cell.

same type

What are the 2 types of stem cells?

1. Embryologic 2. Adult

Adult stem cells act as a _____ in the body, and are located in various \_\_\_\_\_.

repair system, tissues

What 3 locations in the body have adult stem cells?

1. Bone marrow 2. Fat 3. Blood

What are autologous stem cells?

Stem cells collected from the same patient to be treated.

What are allogenic stem cells?

Collected from a donor animal and administered into a recipient patient. (Donor and recipient are the same species)

Concentrate aspirated from bone marrow contains _____ of stem cells within the cellular fraction.

\<1%

What is the significance of BMAC containing \<1% of stem cells?

There is limited ability to directly aspirate bone marrow and then re-administer the concentrate with true stem cell benefit

What can we do with BMAC to ensure a true benefit? How much does this increase the cell content and how long does it take?

Send to a lab to be cell cultured; increases SC content up to 15-30 million cells - takes 3-4 weeks

From where can we get bone marrow aspirations and what instrument is used?

Sternum, tuber coxae, humerus (dogs); Jamshidi needle under sterile technique and local block

What is another name for adipose stem cells?

Stromal Vascular Fraction

What is the difference between stromal vascular fraction and BMAC?

SVF has a significant increase in stem cells compared to equal amounts of BMAC; BUT amount available for therapy (\<1 million) is significantly less than culture expanded bone marrow stem cells (15-30 million)

How many stem cells per 50g of tissue are latent in SVF?

500-750,000

\_\_\_\_\_ therapy remains the largest perceived benefit of adipose stem cells over bone marrow.

Point of care

Where is fat harvested for adipose stem cells and how?

Base of tail head and inguinal region; Direct excision through skin incision, liposuction using repetition of needle aspiration

Both bone marrow and fat derived stem cells are often utilized as _____ therapy.

autologous

What is the largest hinderance to using allogenic stem cells?

Risk of immune reaction to administered allogenic SCs

What are allogenic sources of SCs?

1. Dental pulp 2. Umbilical 3. Amniotic

What are the common routes of administration for stem cells?

1. IV and intra-arterial via tourniquet and regional limb perfusion 2. Direct admin into site of injury/lesion (U/S guided) 3. Intra-articular injection