Table 2.

Summary of Approaches for Lymphatic Tissue Engineering

Technique	Method	Model system	Results	Ref.
Hydrogels	hLECS overlaid with Fibrin, Collagen I, and Fibrin-Collagen I composite hydrogels	In vitro	-In absence of fibroblasts, no capillary formation -When hLECs with 40% dermal fibroblasts, branching capillaries developed within 21 days in vitro	[58]
	Fibrin and collagen ratios varied in hydrogels	In vitro	-LECs organized the most extensively in fibrin-only hydrogels, with slender networks and narrow lumens -Fibrin hydrogels stable for only 6 days	[160]
	hLECs co-cultured with ASCs in fibrin hydrogels and supplemented with VEGF-C	In vitro	-In the presence of ASCs, LECs formed tubules and networks -25ng/mL VEGF-C supplementation improved network formation	[201]
	HA-hydrogel	Lewis rat	-Mice that received HA-hydrogel demonstrated decreased scarring and decreased collagen deposition -HA treated group's ejection fraction was rescued to almost pre-MI baseline	[202]
Biochemical Stimuli	LECs supplemented with VEGF-A and VEGF-C	In vitro	-In vitro formation of lymphatic capillaries -Increased density of lymphatic capillary branching, compared to factor-free medium	[50]
	VEGF-C administered with skin graft	Mouse	-Lymphatic regeneration temporally and spatially associated with pattern of VEGF-C they were exposed to	[43]
	VEGF-C administered with autologous lymph node transfer	Domestic pig (female)	-Induced lymphangiogenesis	[213]
	VEGF-C gene therapy	Mouse, Rabbit	-Regenerated damaged lymphatic networks -Reduced edema	[211, 214–218]
	ANGPT1/2/TIE2	Proposed	-Guide postnatal maturation of LVs	[222]
	TGF-β	Proposed	-Primary ligand in ALK1 pathway which regulates differentiation of premature LECs into mature LECs	[223]
	PDGF-B, HGF, and/or Adrenomedullin	Proposed	-Enhance proliferation, migration, and tubule formation of LECs	[222, 224, 225]
Co-culture	LECs seeded on sheets of fibroblasts	In vitro	-Stable 3D lymphatic capillary networks spontaneously organized without exogenous materials	[228]
	LECs and dermal fibroblasts co-cultured for six weeks	In vitro	-LECs spontaneously organized and formed vasculature that resembled native in vivo tissue -Microvasculature stable for multiple weeks	[226]
Interstitial Flow (IF)	IF through collagen gels containing phorbol 12-myristate 13-acetate	In vitro	-Induced blood and lymphatic endothelial cell organization	[232]
	Low level IF added to 3D fibrin matrix containing VEGF	In vitro	-Complex capillary morphogenesis -Computational model showed that IF created gradient of VEGF	[160, 235]
	IF applied to regenerating skin	Mouse	-Lymphatic vessels only formed in the direction of lymph flow	[236]
	Multichamber radial fluidic device that exposed LECs to IF	In vitro	-LECs formed multicellular, lumenized structures similar to natural lymphatic networks	[200]
Extracorporeal Shockwave Therapy (ESWT)	Ear lymphedema treated with low-energy shockwaves	Rabbit	-Increased expression of VEGF-C and VEGFR-3 -Decreased lymphedema	[239]
	Tail lymphedema treated with low-energy ESWT	Rat	-Increased expression of VEGF-C and bFGF -Decreased lymphedema	[240]
Scaffolds	Collagen and fibrin-based hydrogels vascularized with LECs in vitro, then implanted	Mouse	-Functional vessels developed 15 days after implantation	[220]
	Engineered fibrin-binding VEGF-C (FB-VEGF-C) that is slowly released upon demand of infiltrating cells	Mouse	-FB-VEGF-C act synergistically with IF to drive lymphatic capillary morphogenesis in vitro -Induce local lymphatic hyperplasia but do not remodel downstream collecting vessels	[244]
	Nanofibrillar collagen scaffolds placed across lymphedema area to guide lymphatic regeneration	Porcine	-Increased number of lymphatic collectors in the proximity of scaffold -Bioimpedance ratio improved, implying that functional lymphatic drainage was restored	[245]
Combinatorial	Combinations of gelatin hydrogels, VEGF-C supplementation, and ESWT used to treat lymphedema	Mouse	-Greatest lymphatic vessel formation and greatest decrease in lymphedema resulted when all three approaches (hydrogels, VEGF-C, and ESWT) were combined	[250]