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Regenerative Medicine 1159.e1

Regenerative Medicine Client Education
Sheet
VetBooks.ir Equipment, Anesthesia 6

Difficulty level: ♦♦
This requires two anesthetic procedures (col-
• Stem cell therapy: equipment needed for bone × 10 cells) necessitates culture expansion.
Overview and Goal marrow aspiration (p. 1068) or fat collection lection of tissue from the patient followed
• Regenerative medicine includes therapies (inguinal, subcutaneous or abdominal) by culture expansion and administration), or
aimed at restoring or replacing damaged • PRP, BMAC, SVF: preparation kit/centrifuge if a one-step procedure is desired, allogeneic
tissues in the body. Stem cells and platelet- MSCs can be used.
rich plasma (PRP) are two cell-based treat- Anticipated Time • PRP, MSC, BMAC, and SVF can be admin-
ment options in this field that are rapidly 30 minutes-2 hours istered directly into the site of injury (e.g.,
gaining popularity in veterinary medicine. joint, soft-tissue structure). MSCs have also
• Preliminary studies have shown clinical ben- Preparation: Important been administered intravenously, but there
efits of treatment with autologous (patient’s Checkpoints is controversy about this approach because Procedures and Techniques
own) and allogeneic (from a donor of the • Establish an accurate diagnosis.
same species) stem cells in dogs. Adult stem • Evaluate whether conventional/FDA-
cells, specifically adult mesenchymal stem approved treatments have been exhausted. Hard spin Soft spin
cells (MSCs), are most commonly used in • Review current literature to determine
veterinary medicine. MSCs are multipotent whether regenerative medicine has been
and can differentiate into specific (but not investigated for the desired indication.
all) tissues, which sets them apart from • Discuss current scientific status/benefits/
embryonic stem cells. MSCs are naturally complications with owner.
present in most tissues of adult animals and
people and can be harvested from easily Possible Complications and
accessible tissues such as adipose tissue and Common Errors to Avoid
bone marrow. MSCs can then be isolated • Lack of knowledge regarding the potential
and expanded by various means in the harm/benefit and variability in currently
laboratory. available cell-based therapies
• Because adult MSCs are present in very • If cells injected intravenously, potential
low concentrations in tissues, purification pulmonary or coronary embolization
and culture expansion has to be performed
to achieve a clinically relevant number of Procedure
MSCs. This process takes approximately 7-14 • The steps for PRP-preparation vary based on
days, which negates immediate treatment the manufacturer of the preparation kits. In
when autologous cells are used. Alterna- general, sterile aspiration of venous blood
tive approaches use allogeneic MSCs or from the jugular vein is performed, followed
minimally manipulated aspirates of bone by preparation of the product and immediate Plasma Buffy coat Erythrocytes
marrow (bone marrow aspirate concentrate injection. Sedation is recommended for the REGENERATIVE MEDICINE Platelet-rich plasma
[BMAC]) or fat (stromal vascular fraction collection and injection procedures to maxi- (PRP) preparation using the centrifugation method.
[SVF]). These products contain very low mize sterility during collection and minimize After centrifugation, the blood separates into three
numbers of MSCs with a variety of other iatrogenic trauma during injection of the layers: the top layer contains the plasma, the middle
nucleated cells, and this strategy should not product. Concentration of the platelets is layer (buffy coat) contains the leukocytes, and the
be confused with stem cell therapy. However, most commonly performed by centrifugation bottom layer contains the erythrocytes. Platelets
several studies show that it may still provide (e.g., Arthrex, Companion Animal Health, (black dots) are located at the interface between the
buffy coat and middle or bottom layer, depending
clinical benefits. Harvest Technologies, MediVet, PulseVet). on the speed of centrifugation. Depending on the
• PRP contains a concentrated number of Centrifugation results in three layers: plasma system, one or two spins are performed. The first spin
platelets (i.e., 3-5 times greater than the (containing some platelets), buffy coat (soft spin; approximate RPM: 1200-1500) separates
peripheral blood of the patient). Various (containing some platelets and leukocytes), the erythrocytes from the plasma and platelets. The
growth factors (e.g., platelet-derived growth and erythrocytes. The erythrocytes usually erythrocyte cell layer is then discarded because the
factor [PDGF], vascular endothelial growth are discarded, and depending on the desired cells are generally undesirable for musculoskeletal
factor [VEGF], transforming growth factor product, parts of the buffy coat are also indications. PRP formulations created using a single-
beta [TGF-beta], insulin-like growth factor discarded. Technically, commercially available step procedure have a yellow-tinged color. The second
[IGF]) released from the alpha granules of kits are not necessary for this process, but the spin (hard spin; approximate RPM: 4000-7000) is
performed after transferring the plasma and buffy
the platelets are thought to be associated commercially provided closed systems help coat layer to another tube. This step is used to further
with the beneficial effects of PRP treat- to maintain sterility and are therefore recom- concentrate the platelets and allow purposeful inclu-
ment. However, the many other proteins mended by the author. The other option sion or exclusion of leukocytes. To obtain leukocyte-rich
and cells contained in PRP may also play for PRP preparation, gravity filtration (Pall PRP, the entire buffy coat is used (a small portion
a role. Corporation), results in higher erythrocyte of the RBC layer is included during the transfer to
and leukocyte concentrations when compared the second tube); to obtain leukocyte-poor PRP, only
Indications to other systems. the top layer of the buffy coat is used (resulting
Muscle, tendon, ligament, cartilage, and osseous • BMAC or SVF preparation steps also vary in a lower number of platelets). After completion
pathologies with manufacturer, but these procedures of the second spin, the plasma layer is discarded, and
the remainder of the product is mixed to resuspend
require heavy sedation or general anesthesia
Contraindications for collection of bone marrow or fat. True the platelets. Because the hard spin results in location
of the platelets close to the erythrocyte layer, some
Existing neoplasia, thrombocytopenia, coagula- stem cell therapy (using a clinically meaning- erythrocytes are included in the final PRP product,
tion defects ful number of MSCs of approximately 5-12 resulting in a slightly red-tinged color.
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