Table 1.

Liposomal Hydrogels for Drug Delivery

Hydrogel Composition	Liposome Composition	Drug	Disease	Release	Release Profile	Method of Administration	Ref.
Collagen	N/A	Paclitaxel	Spinal cord injury repair	Hierarchical nano/microstructure provides sustained release of liposomes with the scaffold acting as a second barrier for release	Cumulative release of pristine drug 34% higher than release from liposomal scaffold at 24 hours	Scaffold implantation	(X. Li et al., 2018)
Collagen	DPPC, cholesterol, DSPE-PEG-Mal	Vanomycin	Infection	Liposome retention in the hydrogel enables sustained release which is primarily driven by drug diffusion through the liposome	Cumulative release extended 36 hours using CMP-tethered liposomal scaffold compared to pure drug-loaded scaffold	Topical	(Thapa et al., 2020)
Polyurethane	Lecithin, cholesterol, tocopherol	Paclitaxel	Breast cancer	Burst release is minimized by release of liposomes due to scaffold degradation, then drug release from liposome	Cumulative release from liposomal scaffold plateaus 144 hours longer than release from scaffolds containing Taxol	N/A	(Yin et al., 2020)
Polyethylene glycol	Lecithin, cholesterol, octadecylamine	BMP-2 peptide	Bone defects	Adhesive liposomes diffuse through the hydrogel to damaged tissue, where they attach and enable prolonged drug release	Adhesive liposomal scaffolds exhibit similar release profiles to normal liposomal scaffolds	Scaffold implantation	(L. Liu et al., 2019)
Chitosan, Eudragit RSPO, and polyvinyl alcohol	DSPC, cholesterol, DSPE	Galantamine	Alzheimer’s	Drug release rate determined by the mechanical and physicochemical properties of the gel, which govern diffusional pathways	Cumulative release from non-crosslinked scaffolds up to 40% higher than release from crosslinked scaffolds at 50 days	Scaffold implantation	(Mufamadi et al., 2019)
Chitosan	Lecithin, cholesterol, sodium deoxycholate	alpha-tocopherol	Myocardial infarction	Liposome encapsulated drugs within the hydrogel exhibit sustained release with limited burst	Cumulative release from suspension-loaded scaffolds 16.6% higher than release from liposomal scaffolds at 140 hours	Subcutaneous injection	(Y. Qu et al., 2019)
N/A	PC-C32-PC, Me2PE-C32-Me2PE	Methylene Blue	Bacterial and fungal infection	Drug diffusion is limited by hydrophobic interactions or hydrophobic bonds formed with the bolalipid matrix	Drug release from the bolalipid scaffolds was 46% lower than that of a polymeric hydrogel after 8 hours	N/A	(Goergen et al., 2019)
N/A	PECE, EPC, cholesterol	Madecassoside	Wound healing	Drug diffuses through the bilayer membrane of the liposomes, which are immobilized due to PECE, thus sustaining release	Drug release from the PECE liposome hydrogel was 38% lower than that of a PECE hydrogel after 12 hours	Topical	(Meifeng Liu et al., 2020)
N/A	Phosphatidylcholine, cholesterol, thiolated chitosan	Curcumin	Breast cancer	Pore size controls drug release; higher concentrationsA of liposomes forming the hydrogel form hydrogels with smaller pores, limiting drug release	Drug release reached only 40% after 70 hours for hydrogels containing the highest concentration of liposomes	Injection	(R. Li et al., 2020)
Collagel®	DPPC	Anti-luciferase siRNA	N/A	Hydrogel properties (i.e. crosslinking density, pore size) governs lipopolyplex release	Cumulative release of lipopolyplexes from cGEL5 was equivalent to that of naked siRNA, but without burst release	N/A	(Schwabe et al., 2017)
Hydroxyethyl Cellulose	DOTAP, DOPE, cholesterol, DSPE-PEG	siRNA	Genital diseases	Hydrogel viscosity and concentration can be modified to sustain lipoplex release	Cumulative siRNA release reached only 10% after 4 hours	Vaginal	(Furst et al., 2016)
pHEMA	StemFect™, Lipofectamine™	GFP-mRNA	Immunotherapy or vaccine applications	Lipoplex immobilization in the scaffold slows release and enhances transfection efficiency	Cumulative release of mRNA from lipoplex scaffolds is 3 times lower than systemic mRNA injection	Implantation	(R. Chen et al., 2018)
Chitosan, alginate	StemFect™	Ovalbumin-mRNA	Immunotherapy or vaccine applications	mRNA is released from the lipoplex scaffold as the hydrogel degrades with limited burst release	Release of lipoplexes reached 30% over 2 weeks, compared to 80% mRNA release from gels after 3 days	Subcutaneous Injection	(J. Yan et al., 2019)