Biomedical Engineering Reference
In-Depth Information
Nerve Regeneration Template
1. Make an aluminum foil pouch for each PVC jacket assembly (containing the
silicone processing tube and the matrix). Take a large piece of foil and fold it in
half. The folded edge is now the bottom of the pouch. Take the left edges and
fold, at least twice, to form a sealed side. Repeat on the right side of the pouch.
Insert the PVC jacket assembly into the pouch (one tube per pouch) and leave
the top open. The PVC jacket is left in place to protect the matrix from damage
during handling and storage.
2. Prepare foil pouches (see step 1) for the implantation tubes. Place each implan-
tation tube in a pouch, leaving the top open.
3. Place the matrix-filled pouches (top open) and the implantation tube pouches
(top open) in the vacuum oven for the DHT treatment.9 The conditions of treat-
ment in the vacuum oven are: 30 mTorr, 105 °C, 24 h.
4. After 24 h, remove each pouch and immediately seal the top by folding the top
edges of the foil pouch, at least twice. If the matrix is not being prepared for
immediate use, it can be stored in the foil pouch in a desiccator (up to 1 year)
until needed. The matrix is now sterile and must be handled using sterile proce-
dure from this point.
5. After the DHT process is complete, the matrix can be cut and hydrated for use.
Prepare a sterile field and place in it all-sterile implements, including the PVC
jacket assemblies and implantation tubes. Prepare the operator for sterile work
in gown, cap, coat, and sterile gloves.
6. Under sterile conditions, trim each implantation tube to a length of 20 mm,
using a scalpel.
7. Remove the matrix from the silicone processing tube by making a careful slit
with the scalpel down the length of the silicone tube and gently pulling out the
matrix with forceps. Discard the silicone processing tube.
8. Trim off any crushed or otherwise damaged pieces of the dry matrix. Cut the
remaining portion of the dry matrix into 10-mm segments. The exact length
depends on the experimental design for use for use of the implant.
9. Insert each 10-mm segment of matrix into the center of a trimmed implantation
tube.
10. Place each implant into a specimen jar filled with sterile PBS for hydration and
short term (less than 2 day) storage. If implants will not be used immediately,
store at 4 °C in 70 % isopropanol for up to 30 day. Transfer the implants to ster-
ile PBS solution 1 day prior to implantation.
9
After approx. 2000 the structure of the NRT was prepared in the Yannas laboratory at MIT nearly
identically to that of SRT/DRT with respect to pore size and crosslinking treatment. Also, the GAG
component was omitted (See Yannas I.V. 2015.
Tissue and Organ Regeneration in Adult
. Second
Edition. New York: Springer).
