Table 2.
Applications of essential oils incorporated in hydrogels.
| Method of Preparations | Materials | Encapsulated Essential Oils | Applications | References | |
|---|---|---|---|---|---|
| Biomedical applications | Physical crosslinking | Sodium alginate/Fucoidan | Menthol, L-linalool, bergamot oil, and β-pinene | Topical or transdermal administration | [43] |
| Physical crosslinking | Methylcellulose (10% (w/v)) | Melissa officinalis EO | Treatment of oral candidiasis. | [44] | |
| Chemical crosslinking | Polyvinyl Alcohol/Corn Starch Hydrogel Films loaded with Silver Nanoparticles | Patchouli EO | Antimicrobial materials (against Staphylococcus aureus and Staphylococcus epidermidis) | [45] | |
| Solvent displacement method | Poly-(D,L)-(lactic-co-glycolic acid) | Thyme EO | Inflammatory skin disorders | [47] | |
| Physical crosslinking | Polyvinyl alcohol/kaolin | Cedar EO | Wound dressing | [49] | |
| Covalent and physical crosslinking | Chitosan/oxidized pullulan | Clove EO | Wound dressings | [52] | |
| Cold gelation process | Polymeric-Micelles-Based Hydrogels (Pluronic F127–20%w/w; and Pluronic L 31—1%w/w) | Oregano EO | Cutaneous application | [57] | |
| Chemical crosslinking; casting method | Polyvinyl alcohol/polyvinyl pyrrolidone; hydroxypropyl methyl cellulose; sodium alginate; polyethylene glycol; glycerol; Zn stearate; vitamin A and E | Fennel, pine, mint and thyme EO | Wound dressings | [63] | |
| Chemical crosslinking | Ultrasound-assisted deacetylated chitosan/ρ-coumaric acid | Clove EO | Chemotherapeutic/chemopreventive agent | [75] | |
| Thin-film dispersion technique/heat-induced gelation. | Pea protein (30%) and gum Arabic (1.5%); Soybean lecithin; maltodextrin and gum Arabic | Thyme EO | Delivery of bioactive compounds (food packing material, tissue engineering or drug delivery) | [79] | |
| Physical crosslinking | Carboxymethyl chitosan/carbomer 940 | Eucalyptus, ginger, and cumin EO | Burn dressing material for skin burn repair | [86] | |
| Dental applications | Physical crosslinking | Xanthan gum/Glycerin/Lyophilized Whey/Polyvinylpyrrolidone/PEG 400 | Oregano®, Frankincense®, Thieves®, Frankincense® EO | Therapy of periodontitis | [94] |
| Cosmetics applications | Ionic gelation | Poly(vinyl alcohol), silk sericin, and gelatin/chitosan nanoparticles | Camellia oleifera EO | Cosmetic product (facial masks) | [104] |
| Food applications | Emulsification/ionic crosslinking | Pectin and pectin/chitosan hydrogel beads | Green and roasted coffee EO | Systems for the delivery and controlled release of essential oils; food applications | [111] |
| Food packaging applications | Gelation/casting | Sodium alginate/acacia gum | Cinnamon EO | Hydrogel-based films as active food packaging materials | [129] |
| Restorations of the stone cultural heritage | Preparation directly in situ | Sodium alginate | Thyme EO | Biocides for restoration in a real case of study, i.e., the mosaic Le Professioni e le Arti of Fortunato Depero | [146] |