Application and prospect of adipose stem cell transplantation in treating lymphedema

Table 1 Adipose-derived stem cell-based treatment of lymphedema in animal studies

Year	Ref.	Animal	Location and methods	Groups	Cell type used for characterization and number	Implantation methods	Assessment	Results
2011	Hwang et al[25]	6-8-wk-old female BALB/c mice	Hindlimb, Circumferential incision and electrocautery	5 groups (n = 5 for each group): Normal, control, hADSCs, VEGF-C hydrogel, hADSCs/VEGF-C hydrogel	PKH-26-labeled hADSCs N/A	In combination with VEGF-C gelatin hydrogel subcutaneous injection	Dermal edema depth measurement using Vernier calipers	Co-administration of hADSCs and VEGF-C decreased dermal edema depth and increased lymphatic vessel intensity
							H&E staining
							IFC (LYVE-1) for lymphatic vessel intensity
2012	Shimizu et al[26]	7-8-wk-old male C57BL/6J mice	Tail 2 mm-wide circumferential annulus of the skin excision at 10 mm distal to the tail base, excluding a 4 mm2 dermal flap located at the ventral side	3 groups (n = 12 for each group): Sham, PBS, and freshly isolated ADRCs	Freshly isolated ADRCs 2 × 106	Local injection	Tail thickness measurement	Local injection of ADRCs significantly reduced lymphedema ADRC implantation accelerated lymphangiogenesis ADRC implantation enhanced recruitment of M2 macrophages, to serve as lymphatic endothelial progenitor cells
							IHC analysis (LVYE-1)
							IFC staining (LYVE-1, CD11-b, CD163)
2015	Ackermann et al[27]	10-wk-old male C57BL/6J mice	Tail Circumferential 5 mm-wide full thickness excision at a 10 mm distance from the base of the tail	3 groups: Saline, PRP, and ASC	Allogenic 3 passages FACS analyzed (CD31−/CD45−/CD29+/CD90+ cells	Injection	Angiogenesis (anti-CD31 staining)	Wounds treated by PRP and ASC healed faster and showed a significantly increased epithelialization
							Laser Doppler imaging for microcirculation	Application of PRP induced a significantly increased lymphangiogenesis, while application of ASC did not induce any significant change, in this regard.
							Lymphangiogenesis (anti-LYVE1 staining)
							Corrosion casting for microvascular architecture
							Digital planimetry for wound healing
2015	Yoshida et al[28]	Male C57BL/6J mice	Right hindlimb, 30-gray x irradiation, surgical lymph node dissection, and 2-mm gap creation	4 groups (n = 20 for each group with different cell numbers)	Allogenic up to 5 passages 0, 106, 105, 104	Subcutaneous injection	Circumference measurement	Number of lymphatic vessels significantly increased at 2 wk
							Near-infrared video camera for lymphatic flow assessment
							IHC for quantitation of lymphatic vessels (LYVE, VEGF-C, VEGFR, and EGFP)	No direct detection of ADSCs involving lymphangiogenesis by EGFP at 2 wk or chromosome FISH at 2 wk and 4 wk
							XY chromosome FISH analysis
2017	Hayashida et al[29]	10-wk-old male C57BL/6J mice	Left hindlimb, 30-Gy X-ray irradiation, surgical lymph node dissection, and 5-mm gap creation	4 groups (n = 5 for each group): Control, VLNT, ADSCs, VLNT-plus/ADSCs-plus	Allogenic 1-3 passages at 104	VLNT, subcutaneously	Near-infrared video camera for lymphatic flow assessment	Increased number of lymphatic vessels
							Water-displacement plethysmometer for hind-paw volumetry test	Induced lymphatic flow drainage to the circulatory system
							IHC for tissue quantification of lymphatic vessels (LYVE-1, VEGF-C, and VEGF-R3)
							B16 mouse melanoma cells for functional analysis of lymphatic vessels and nodes

ADRCs: Adipose-derived regenerative cells; ADSCs: Adipose-derived stem cells; ASC: Adipose stem cells; EGFP: Enhanced green fluorescent protein; FISH: Fluorescent in situ hybridization; H&E: Hematoxylin and eosin; hADSCs: Human adipose-derived stem cells; IFC: Immunofluorescence; IHC: Immunohistochemistry; N/A: Not applicable; PBS: Phosphate-buffered saline; VEGF-C: Vascular endothelial growth factor-C; VEGF-R3: Vascular endothelial growth factor-receptor 3; VLNT: Vascularized lymph node transfer.

Table 2 Adipose-derived stem cell treatment of lymphedema in clinical trials

Year	First author	Study type	Patientnumber,test/control	Edemalocation	Cell type	Cell number	Injection method,location/depth	Follow-up inmoassessment	Results
2016	Toyserkani et al[30]	Pilot study	1/0	Upper limb	Freshly isolated autologous ADSCs plus fat graft	4.07 × 107 plus 10 mL lipoaspirate	Axillary region (8 points)	4 mo In vitro cell characterization (cell count, viability, and surface marker)	Great reduction in symptoms of arm heaviness and tension, reduction in need for compression therapy
								Circumference measurements	Volume reduction in affected arm
								Dual-energy X-ray absorptiometry scans Adverse events	No postoperative complications or adverse events
2017	Toyserkani et al[31]	Pilot study	10/0	Upper limb	Freshly isolated autologous ADSCs plus fat graft	5 × 107 plus 30 mL lipoaspirate	Axilla (8 points)	6 mo In vitro cell characterization (cell count, viability, and surface marker)	A small volume reduction but not significant
								Circumference measurements	Patient-reported outcomes improved significantly over time
								Dual-energy X-ray absorptiometry scans	Half of the patients reduced their use of conservative management
								Patient-reported outcome and safety questionnaire assessment	No noteworthy serious adverse events
2019	Toyserkani et al[32]	Pilot study	10/0	Upper limb	Freshly isolated autologous ADSCs plus fat graft	5 × 107 plus 30 mL lipoaspirate	Axilla (8 points)	12 mo In vitro cell characterization (cell count, viability, and surface marker)	No significant change in volume
								Circumference measurements	Patient-reported outcomes improved significantly over time
								Dual-energy X-ray absorptiometry scans	Five patients reduced their use of conservative management
								Patient-reported outcome and safety questionnaire assessment	Quantitative lymphoscintigraphy showed no improvement on the lymphedema-affected arms
								Lymphoscintigraphy changes	ADRCs were well-tolerated and only minor transient adverse events related to liposuction were noted

ADRCs: Adipose-derived regenerative cells; ADSCs: Adipose-derived stem cells.