Nano-Lipidic Carriers as a Tool for Drug Targeting to the Pilosebaceous Units

Abstract

: The pilosebaceous unit is the triad comprising of hair follicle, arrector pilli muscle, and sebaceous gland. Drug delivery to and through the hair follicles has garnered much attention of the researchers and the hair follicles represent an attractive target site via topical applications. They are bordered by capillaries and antigen-presenting cells, connected to the sebaceous glands and the bulge region of the hair follicle anchors the stem cells. The nano lipid carriers have the propensity to penetrate through the skin via transcellular route, intracellular route and follicular route. It has been established that nano lipid carriers have the potential for follicular drug delivery and provide some advantages over conventional pathways, including improved bioavailability, enhanced penetration depth, fast transport into the skin, tissue targeting and form a drug reservoir for prolong release. This review describes the pilosebaceous unit (PSU) and related diseases and the recent lipid-based nanotechnology approaches for drug delivery to the follicular unit as well as related tissues. Different types of nano lipid carriers including ethosomes, liposomes, nanoparticles, solid lipid nanoparticles (SLNs), and nano lipid carriers (NLCs) have been reported for follicular drug delivery. Targeted drug delivery with nano-lipid carriers has the potential to augment the efficacy of drugs/bioactives to treat diseases of PSU. This review systematically introduces the activities of different formulations and use of nano lipid carriers in treating PSU related disorders like alopecia, acne, and hirsutism.

Advances in nanotechnology‐based hair care products applied to hair shaft and hair scalp disorders

“…For example, despite all research efforts and exciting results, there are still no commercially available nano-sized products aiming to achieve the inner portion of hair follicles. The success of hair follicle targeting is closely related to particle size water-oil partition capacity [62][63][64][65]. Moreover, local massage is an effective adjuvant to the penetration of nanoparticles into hair follicles [66].…”

Lipid-Based Nanosystems as a Tool to Overcome Skin Barrier

“…The first one is via a tortuous path through the lipids surrounding the corneocytes, while the second one is more restrictive, as molecules must pass through both corneocytes and the intercellular lipids. Finally, the third path (follicular route) by using hair shafts and sebaceous glands allows the penetration of molecules through hair follicles openings [ 51 , 52 ]. However, the passage across the skin of these highly deformable (ultra-flexible) transfersomes is mainly attributable to the membrane flexibility, hydrophilicity, and the ability to maintain the vesicle’s integrity (as schematized in Figure 3 ) [ 50 , 53 , 54 ].…”

“…It should be noticed that the presence of ethanol seems to have a significant role on the permeation flux; thus, the larger the ethanol content, the greater the permeation flux [ 73 ]. Notwithstanding, the follicular route of skin penetration has been proposed as a possible mechanism of ethosomes delivery; therefore, the exact process of transdermal delivery is still under investigation [ 52 ].…”

Nanodrug Delivery Strategies to Signaling Pathways in Alopecia

“…8,9 The HF structure during anagen is complicated, consisting of three major layers from the inner core to the epidermis. 10 At the lower part of the HF, the dermal papilla cells (DPCs) and proliferating keratinocytes (matrix progenitor cells) are surrounded by dermal sheath cells (DSCs). The sebaceous gland, hair shaft, the inner root sheath (IRS), and the outer root sheath (ORS) constitute other parts of HF.…”