Table 2 Detailed methodology of selected studies

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