10.1 Skin tissue structure
Keratinocytes, fibroblasts, hair follicles and immune cells are clearly stratified, and the stratum corneum forms an important delivery barrier.
10.2 AAV serotype selection
AAV2/6/8/9 can be compared by cell and wound status; in vitro keratinocyte results need to be reviewed in intact skin or wounds.
10.3 Skin-specific promoter
KRT14/KRT5 favors basal keratinocytes, IVL favors differentiated keratinocytes, and COL1A1 favors fibroblasts.
10.4 Administration method and dosage reference
Intradermal injection: targeting the basal layer of the epidermis and dermis. Mouse working concentration is 1×10^12 vg/mL, approximately 2×10^10 vg per point, 10-20 μL per point, 29-31 The tip of the G insulin needle is inserted into the skin at an angle of 10-15°, and the wheal is confirmed to be in the skin; AAV2/6 transduces basal keratinocytes (KRT14 promoter), and COL1A1 targets dermal fibroblasts; it is expressed for 2-4 weeks [10-3].
Local application on wounds: intradermally inject a total of 80-120 μL at 4-6 points per wound, or drop it directly onto the wound bed and then cover it with Vaseline gauze/hydrogel scaffold to prevent loss; wound repair cells (keratinocytes, fibroblasts, macrophages) can all be transduced. 50-100 μL per point in rats; the structure of pig skin is highly similar to that of humans, making it a transformation model [10-1, 10-3].
Coverage and limitations: The intact stratum corneum of skin is the main barrier for transdermal penetration, and intradermal injection is limited to a few millimeters around the injection point; injection depth, positive area, cell co-localization, inflammation and wound repair endpoints should be reported [10-2].
10.5 Key research evidence
Keswani et al. reported the tropism of AAV vectors in wound healing in mice [10-3]; Kurita et al. generated skin epithelial tissue through in vivo reprogramming of wound-resident cells [10-1]; Shen et al. optimized AAV for in vitro and in vivo delivery of epidermal keratinocytes [10-2].
10.6 References for this chapter
[10-1] Kurita M, et al. In vivo reprogramming of wound-resident cells generates skin epithelial tissue. Nature. 2018;561:243-247. [H]
[10-2] Shen Q, et al. Optimization of an AAV vector for epidermal keratinocytes in vitro and in vivo. J Dermatol Sci. 2024;115:101-110. [N]
[10-3] Keswani SG, et al. AAV vector tropism in murine wound healing. Wound Repair Regen. 2012;20:592-600. [F]