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Table 2 Detailed methodology of selected studies

From: Systematic review: Advances of fat tissue engineering as bioactive scaffold, bioactive material, and source for adipose-derived mesenchymal stem cells in wound and scar treatment

Authors Harvest’ procedures SVF/AD-MSC isolation procedures SVF yield Administered solution Administration route to the recipient site Cannula/needle Age of patients Age of scar(s) Follow-up period
Wu et al. [17] Site: anterior abdominal
Infiltration: standard Klein solution
Technique: 2-mm inner diameter cannula (Mentor BENSAT 330)
Negative pressure limited to 350 mmHg
Volume: N/A
1. Lipoaspirate washed three times with saline
2. Gravitational decanting—aqueous phase removed
3. 1000 RCF, 3 min
4. Decantation of oil and aqueous phase
5. Spectroscopy (EP2346989 A1) to isolate SVF-rich fat
N/A 100 + 60 ml SVF. Subsequently 0.5ml autologous serum + 1ml hyaluronic acid (HA) filler; 0.1 PZ-U/ml NB6 collagenase Subdermal, 100 ml, reverse injections, 3–5 ml per pass layering thin ribbons of graft to reach 20% overcorrection: serum + HA—cross-hatched manner—ring around and underneath the scar sub-dermally; collagenase intradermally SVF: blunt spatulated tip
HA + serum: 22G spinal needle
Collagenase: 25G needle
N/A 2 YO Days 1–5 and 1, 2, 4, 8, and 12 weeks (Ws)
Gentile et al. [18] N/A A) SVF-enriched fat
1. Commercial Celution System use
2. Additional wash and centrifugation cycles
3. 5 ml of the enriched fat extracted
4. Added to harvested fat graft
B) Coleman’s fat mixed with 0.5 ml of PRP. Fat subjected to centrifugation at 3000 RPM; AFT:PRP = 1ml:0.5ml
C) Coleman’s fat
50,000–250,000 nucleated cells per milliliter of fat (automated count–manual count) Group A: SVF-enriched fat grafts (up to 10ml, of which 5ml of SVF)
Group B: 1ml of Coleman’s fat + 0.5 ml PRP
Control group: Coleman’s fat
A) Sub-dermally
B) Sub-dermally, small tunnels were previously created, cannulas with 1.5-mm diameter
N/A 21–69 YO N/A 1 y (quantitative data report); mean 60 months (MO)
Carstens et al. [19] Site: N/A
Infiltration: N/A
Technique: directly into a sterile processing canister (GID SVF-1)
Negative pressure: N/A
Volume: 108 ml dry fat
1. Washed three times with saline
2. 125 ml of lactated Ringer’s + collagenase enzyme 200CDU/ml
3. Incubation—40 min, 38 °C, 150 RPM
4. Centrifugation for 10 min at 800g
5. Removal of SVF from the bottom of the device
>4 × 107 mononuclear cells (5 × 105/g of dry fat) 1) 2ml of SVF containing a total of 6 × 106 SVF-derived cells
2) 20ml of SVF enriched with a total of 2.7 × 106 SVF-derived cells
1) Divided and injected into 4 MCP joints
2) Into subcutaneous space of the dorsum of the hand
N/A 58 YO 4 YO 6 Ws; 6, 12, and 24 MO
Elkahky et al. [20] Site: abdomen
Infiltration: modified Klein’s solution
Technique: blunt-tipped cannula
Negative pressure: N/A
Volume: 250ml
1. Washed 4–6 times with PBS
2. Digestion with 0.2% collagenase at 37 °C for 60 min with agitation
3. DMEM addition to inactivating collagenase
4. Centrifugation at 1500 RPM for 5 min
5. Cellular pellet resuspension in fetal bovine serum and passing through the 100-μm filter to remove debris
6. SVF collection
7. SVF was photoactivated using the AdiLight1 System (Adistem Pty) for 15 min
7 to 86 × 106 cells/sample SVF resuspended in 10% fetal bovine serum Intradermal injections N/A AT-ASC, 20 to 43 years (mean 26.3 ± 7 years)
PRP group, 20 to 44 years (mean 28.7 ± 5 years)
N/A 1 and 3 MO
Zhou et al. [21] Details N/A, lipo-aspiration from 2 subjects (allogenic) 1. Lipoaspirate digested with 0.75% collagenase type II under gentle agitation for 45 min at 37°C
2. Centrifugation at 300g for 10 min
3. Pellet filtered with a 70-μm nylon mesh filter
4. Resuspension in PBS
5. Centrifugation at 840g for 10 min
6. Supernatant discarded
7. Cell fraction cultured overnight at 37 °C/5% CO2 in culture medium
8. Cell population maintenance for 3–5 days until confluence
9. Medium changed to PBS-free DMEM
10. Exposition to hypoxia (2% O2/5% CO2 and balanced N2) for 72 h
11. Centrifugation at 300g for 5 min
12. Filtered using a 0.22-mm syringe filter
N/A 3 ml of ADSC-CM Topically applied onto fractional laser-treated sites N/A 24 to 50 years (mean age 36.4) N/A 1 MO after the last treatment session
Gentile et al. [22] Site: N/A
Infiltration: N/A
Technique: Coleman cannula 3-mm diameter with side sharp holes of 1 mm in diameter, luer-lock syringes
Negative pressure: no high negative pressure (no details)
Volume: 80ml
A) Classic mechanical emulsification—30 passes
B) 160 ml—divided into 1st and 2nd part
a. 1st part:
i. Automatic filtration (120-μm filter)
ii. Centrifugation at 1300 RPM for 10 min
iii. SVF pellet collection and SVF suspension filtered (120-μm filter) to final 20 ml
b. 2nd part was classically emulsified (30 passes)
c. Mixing 1st:2nd 0.2:1
C) Lipoaspirate was centrifuged at 1300 RPM for 10 min, SVF pellet was discarded, and the remaining fat layer was emulsified (30 passes)
D) Lipoaspirate slow centrifugation at 80g for 3 min with Adipecons in 16 ml stocks, further mechanical emulsification (30 passes)
Mean of 5 samples:
A. Classic nano-fat 20,000 ± 3000
B. Supercharged nano-fat 200,000 ± 15,000
C. Centrifuged modified nano-fat 53,334 ± 8000
D. Evo-modified nano-fat 125,000 ± 12,000
A. Classic nano-fat
B. Supercharged nano-fat
C. Centrifuged modified nano-fat
D. Evo-modified nano-fat
Intradermal injections 27G 20–73 YO N/A 3, 4, 6, and 12 MO
Tenna et al. [23] Site: lower abdomen, flanks, hips, and thighs
Infiltration: 20 ml of 0.9% NaCl solution, carbocaine 2%, and adrenaline 1/200,000
Technique: 3-mm Coleman aspiration cannula
Negative pressure: manually generated
Volume: N/A
1. Lipoaspirate centrifuged at 3000 rpm for 3 min
2. Oil removed, and fluid decanted
3. Mechanically emulsified after rinsing, 30 passes through usual connector
N/A 10 ml of nano-fat (7 ml) plus PRP (3 ml) Sub-cutaneous under deformities 19G cannulas 18 to 52 YO N/A 1, 3, and 6 MO
Ghareeb et al. [24] Site: preferably abdomen
Infiltration: 1000 ml of 0.9% saline solution, one ampoule of adrenaline 1 mg/ml, and 15 ml of lidocaine hydrochloride 2% without adrenaline
Technique: 3-mm cannula with 50-ml syringe
Negative pressure: manual
Volume: N/A
Lipoaspirate centrifuged at 3000 RPM for 3 min
The purified fat underwent mechanical emulsification (30 passes, through the usual connector)
N/A Classic nano-fat Intradermal and subdermal injection of nano-fat 27G sharp needles 8 to 48 YO N/A 5 days, 2 Ws, 1, 3, and 6 MO
Carstens et al. [25] Site: flanks and abdomen
Infiltration: N/A
Technique: N/A
Negative pressure: N/A
Volume: 250–350ml
1. Lipoaspirate washed three times with sterile Lactated Ringer’s Solution
2. Collagenase added—200 CDU/ml of total volume, 40 min incubation at 38 °C and 150 rpm
3. Human serum albumin was added (2.5% solution v/v)
4. Centrifuged, 10 min at 800g
5. Pellet resuspended in 15 ml Hartmann solution
2.37–9.83 × 107 viable cells/g of fat SVF Subcutaneous injection 19G needle 26 ± 6.22 YO 6.7 ± 4.3 YO 6 MO
Bhooshan et al. [26] Site: N/A
Infiltration: N/A
Technique: 3-mm mirrored triport Coleman’s cannula
Negative pressure: manual
Volume: N/A
Lipoaspirate mechanically emulsified by 30–35 passes through triport connector N/A Classic nano-fat Intralesional 27G needle 32.2 ± 12 YO 3 to 204 MO (17 years); 79.4%—scars <5 years, 20.6%—scars > 5 years 3 months
Gu et al. [27] Site: peri-umbilically
Infiltration: 20 ml of lidocaine, 0.5%, and 1 ml of 1:1000 epinephrine per 1000 ml of saline
Technique: 3-mm multi-hole aspiration cannula to a 20-ml syringe
Negative pressure: manual by a retracted plunger
Volume: N/A
1. Saline rinsing and filtering
2. Centrifuged at 3000 rpm for 3 min
3. The oil layer was decanted, and the aqueous component drained.
4. For mechanical emulsification, through connected to the Tulip transfer connector with three 1.4-mm holes 30 passes
5. Centrifuged again at 3000 rpm for 3 min
N/A Condensed nano-fat Intradermally, after 18G needle is introduced to break underlying adhesions of the scar. Volume restored sub-dermally with fat graft combined with condensed nano-fat through a blunt 1.2-mm cannula 29G needle/1.2 mm blunt cannula 21–62 YO, mean 38.25 YO 3 to 26 years (mean formation time, 7.45 years) 6 months
Lee et al. [28] Site: abdomen
Infiltration: N/A
Technique: 3-mm blunt-tipped cannula. Liposuction kit used (Lipokit)
Negative pressure: N/A
Volume: 50 ml
1. Centrifugation at 3500 RPM for 4 min
2. Discarding the lower layer (20ml left)
3. Adding collagenase type II and incubation for 30 min in 37 °C (MaxSTEM kit)
4. Centrifugation at 3500 RPM for 3 min
5. Wash in Hartmann solution with 5% dextrose saline and gentamicin
6. Steps 5 and 6 repeated 3 times
5.9 × 107 cells per ml 2 ml of SVF Subcutaneous and intradermal, no more than 5 ml/case N/A Study 1, 14–64 YO (37.47 ± 13.2)
Study 2, 19–65 (35.8 ± 14)
Study 1, 3–240 MO (22.3 ± 51.8)
Study 2, 0–18 MO (6.53 ± 4.47)
6 MO
Uyulmaz et al. [29] Site: chosen individually
Infiltration: 900 ml NaCl 0.9%, 0.25 ml adrenaline (1 mg/ml), 20 ml of lidocaine (20 mg/ml)
Technique: Tonnard 2.4 mm × 20 cm cannula with sharp side 1 mm holes
Negative pressure: N/A
Volume: 10–800 ml, mean 165
1. Wash with isotonic saline solution
2. Mechanically emulsification 30 passes (2.4-mm Tulip connector)
3. Filtration through a nylon cloth with 0.5-mm pore size
N/A Classic nano-fat 1 to 25 ml (mean, 4.6 ml) Injected intralesionally or intra-dermally 24, 25, or 27G sharp needles 15 to 64 years (mean, 42 years) 15 to 40 years (mean, 5.8 years) 155 ± 49 days (range, 87–312 days)
Abou Eitta et al. [30] Site: abdomen, thighs, buttocks
Infiltration: modified Klein’s solution
Technique: blunt-tipped cannula, 60-ml syringe
Negative pressure: probably manually
Volume: ~ 50 ml
1. Lipoaspirate washed with PBS and antibiotics/antimycotic
2. Gravitational decanting and discarding of infranatant
3. Steps 2 and 3 repeated 6 times
4. Collagenase type IA and incubation for 37 °C for 1 h
5. Infranatant with SVF aspirated and DMEM with 10% FBS added to inactivate the collagenase
6. Centrifugation at 300g for 10 min
7. SVF pellets collected with PBS, filtration with a 100-μm cell strainer
8. Centrifugation at 300g for 5 min
9. Optional RBC lysis buffer at room temperature for 5 min; then centrifuged again for 5 min
10. Pellet washed twice with PBS
11. Resuspended in 1ml PBS, ready for injection
Average, 6 × 106 cells SVF suspended in 1 ml PBS Reported as injected intradermally (but underneath atrophic scars) N/A 20 to 45 YO (mean 33.20 ± 6.51) N/A 1, 2, and 3 MO
Malik et al. [31] Site: abdomen, thighs
Infiltration: Ringer lactate with epinephrine 1:400,000
Technique: liposuction cannula (no details) connected with a 10-ml syringe
Negative pressure: manually, plunger pulled back only a few ml (?)
Volume: 25–65 ml, mean 34 ml
1. Gravitational decanting, oil, and aqueous phase discarded
2. 0.075% collagenase added, incubated for 30 min at 37 °C with agitation
3. Centrifugation at 1200 RPM for 5 min
4. Collection of SVF from the pellet
N/A SVF, 10 ml? Under scar—subcutaneous Blunt infiltration cannula 22–45 YO, mean 32.1 N/A 1 and 6 MO
Jan et. Al [32] Site: abdomen, lateral thigh, and/or the gluteal region
Infiltration: 0.9% saline 1000 ml, lidocaine 30 ml, and 1 ml of 1:1000 epinephrine
Technique: 3-mm cannula with multiple sharp side holes of 1 mm attached to a 20-ml syringe
Negative pressure: plunger back by 2 ml
Volume: N/A
1. Lipoaspirate rinsed with 0.9% saline
2. Emulsification by 30 syringe-syringe passes (unknown connector)
N/A Classic nano-fat Selective intradermal or subdermal pre-tunneling. Fanwise pattern with a 1-ml syringe until the skin blanched or yellowish 18G 22.25 ± 5.79 y >1YO 6 MO
Shalaby et al. [33] Site: preferably abdomen or flanks/inner knees
Infiltration: 500 ml of 0.9% saline solution, adrenaline 0.5 mg/ml, and 20 ml of lidocaine hydrochloride 2% without adrenaline
Technique: Unknown cannula, 20-ml syringe
Negative pressure: retracted plunger
Volume: N/A
1) Lipoaspirate washed with Lactated Ringer, incubated 3 min
2) Centrifuged at 3000 RPM 3 min
3) Middle layer preserved
4) Mechanically emulsified by shiftings by 30 passes through 2.4-mm tulip connector
5) Another 30 passes with using (1.4-mm tulip connector)
6) 600-μm nanofat filtration
N/A Nano-fat or nano-fat + PRP Superficial intradermal nano-fat and additional subdermal injection 28G needle and 22–23G cannula 32.8 ± 11.2 YO (nano-fat + PRP); 26.5 ± 9.1 YO (nano-fat) 6.8 ± 7.6 YO (nano-fat + PRP); 3.3 ± 2.7 (nano-fat) 3 MO
Pallua et al. [34] Site: preferably abdomen and/or others
Infiltration: adrenaline suspended in saline solution in a ratio of 1:200,000
Technique: blunt-tipped thin cannula, with a diameter of 2 mm, and 4 orifices, each gauge measuring 600μm
Negative pressure: N/A
Volume: N/A
1. Lipoaspirate is centrifuged at 1200g for 3 min
2. The oily and watery layers removed
3. Manual emulsification by 30 passes, usual connector
4. Centrifugation at 1200g for 3 min
5. Middle layer preserved
N/A Condensed nano-fat, in 1 case supplemented with PRP Various author’s preparation of recipient site before injections. Sub-cutaneous and/or intradermal 27G cannula 41.33 ± 10.53 N/A 6–12 MO