Inventors: Hantash, Basil M.; Frangineas, George; DeBenedictis, Leonard C
Publication date: 2007-09-13
Invention summary:
Treating or preventing hair loss comprises irradiating skin with laser irradiation to form many micropore channels and implanting composition into the micropore channel, where the composition comprises stem cells and growth media
Abstract:
A method of restoring hair to skin that has suffered hair loss includes optically ablating an array of spaced-apart microchannels or voids into the skin and transplanting into the voids stem cells, a scaffold and a differentiation factor for causing the stem cells to differentiate into hair follicles
First Claim:
An apparatus for treating or preventing hair loss in a subject in need thereof, the apparatus comprising handpiece movable over skin wherein the handpiece is arranged to receive an optical beam and focus the optical beam at a plurality of spaced-apart locations on the skin thereby creating a plurality of voids in the skin for the deposition of a composition, wherein the composition comprises a stem cell and a growth media
Background:
Alopecia, or hair loss, is a common problem in men and women worldwide. Currently, only a few treatment options exist. These are topical rogaine (minoxidil) and oral propecia (finasteride). Neither treatment is particularly effective and propecia is only approved for use in men. Alopecia has a significant impact on quality of life, mainly by causing emotional trauma and diminishing self-esteem. Recently, a light-based application has been developed for the treatment of alopecia; however, this therapy has been disappointing to date.
The standard of care is hair transplantation surgery. This treatment involves removal of a band of hair from the posterior scalp followed by hair follicle isolation and subsequent implantation into pre-cored posterior implantation sites over the region of interest. A problem with this process is that it is quite tedious, as only between about 500 to about 800 hairs may be transplanted in a half-day session. This represents merely a nominal amount of hair when considering the fact that a full scalp bears close to one-million hairs. Furthermore, hair transplantation is limited by the availability of remaining hair on the patient's scalp. Accordingly, this procedure is best performed earlier in the natural history of the disease, a time when patients may not be prepared to undergo such an extensive surgical intervention. Because of this, a lot of patients choose to undergo artificial hair transplantation, but this procedure, although simpler to perform, leads to unnatural aesthetic appearance. A method of promoting hair growth non-invasively is therefore desirable.
One possible method would be to introduce stem cells capable of differentiating into a hair follicle phenotype in order to promote hair growth on human skin. Stem cells have recently received a significant amount of attention due to their potential to regenerate tissue and organs. For example, stem cells isolated from the hair bulge region of the follicle explanted into nude mouse skin have given rise to hair follicles and sebaceous glands in animal models. To date, no method has been developed in order to utilize stem cells in humans to grow hair and treat problems such as alopecia.
One problem with using hair-bulge stem cells is the difficulty of isolating this rare cell from the donor. Although methods exist for expanding the stem cell in vitro, each passage of stem cells during tissue culture diminishes the odds that multipotential differentiation is preserved. Furthermore, specifically for the hair-bulge stem cell, expansion may not be feasible, as much of the current scientific experimentation suggests that hair-bulge stem cells lose their ability to differentiate into hair follicles after the first passage. In addition, to avoid issues of immune-dependent rejection, the recipient must also serve as the donor.
Another problem lies in finding an effective method of implanting the stem cells. Such a method must be relatively painless and preferably capable of being implemented over relatively large areas, for example, one-hundred square centimeters (cm2) or more. Previous scientific experiments on animals have involved an instrument-dependent, “cookie-cutter” approach of mechanically perforating or cutting skin to provide channels for receiving the stem cells. Problems of pain and wound healing notwithstanding, such an approach is almost as tedious and time consuming as the above discussed hair-transplanting. Absent a solution to these problems, implementation of such a method in humans may remain quite difficult and even impossible to commercialize
Summary:
The present invention is directed to compositions and methods of restoring hair to skin that has suffered hair loss. In one aspect, the inventive methods include irradiating the skin with laser radiation in a manner such that a plurality of elongated spaced-apart voids are formed in the skin. The voids extend into the dermis of the skin. Stem cells and at least one hair follicle differentiation factor are implanted into the voids for promoting hair growth in the skin.
In one aspect of the invention, laser ablation forming the spaced-apart voids causes the voids to be surrounded with coagulated tissue immediately following the irradiation. There is viable tissue remaining between the voids. The coagulated tissue is under tension resulting from collagen shrinkage by heat generated during the abrasion process. The tension in the coagulated tissue shrinks the voids. The stem cells, a scaffold, and the differentiation factor or factors are deposited into the voids. A healing process completely replaces the coagulated tissue with new tissue after a period of about one month.
In another aspect, the present invention provides an apparatus for treating or preventing hair loss in a subject in need thereof, the apparatus comprises a handpiece movable over skin wherein the handpiece is arranged to receive an optical beam and focus the optical beam at a plurality of spaced-apart locations on the skin thereby creating a plurality of voids in the skin for the deposition of a composition, wherein the composition comprises a stem cell and a growth media
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