The Experts below are selected from a list of 2943 Experts worldwide ranked by ideXlab platform

Norman D. Weiner - One of the best experts on this subject based on the ideXlab platform.

  • Targeted follicular delivery of macromolecules via liposomes
    International Journal of Pharmaceutics, 1998
    Co-Authors: Norman D. Weiner
    Abstract:

    Abstract The hair follicle, hair shaft and sebaceous gland collectively form what is recognized as the Pilosebaceous Unit. This complex, 3-D structure within the skin, possesses a unique biochemistry, metabolism and immunology. Recent studies have focused on the hair follicle as a potential pathway for both localized and systemic drug delivery. Targeted drug delivery may enhance current therapeutic approaches to treating diseases of follicular origin. In a growing number of topical studies, liposomes have been shown to target drug delivery to the Pilosebaceous Unit. Presented here is a summary of some of our recent work with a particular focus on studies which have demonstrated targeted follicular delivery via liposomes.

  • Targeted delivery to the Pilosebaceous Unit via liposomes
    Advanced Drug Delivery Reviews, 1996
    Co-Authors: Andrea C. Lauer, Linda M. Lieb, Chandrasekharan Ramachandran, S. M. Niemiec, Norman D. Weiner
    Abstract:

    Abstract The significance of the Pilosebaceous Unit (hair follicle and sebaceous glands) as a route for passive drug delivery into the skin remains a controversial subject. The Pilosebaceous Unit is a complex, dynamic structure, which is the site of unique biochemical, metabolical and immunological events. Recent topical delivery studies have employed increasingly systematic, quantitative methodologies in attempts to define the follicular pathway. Targeting specific sites of the hair follicle may represent a feasible therapeutic approach, as several dermatological abnormalities are known to originate at the hair follicle. In a growing number of topical delivery studies, liposomes have been shown to target drug delivery to the Pilosebaceous Unit. This review will describe general aspects of follicular delivery, with a particular focus on studies which have demonstrated targeted follicular delivery via liposomes.

  • Transfollicular Drug Delivery
    Pharmaceutical Research, 1995
    Co-Authors: Andrea C. Lauer, Linda M. Lieb, Chandrasekharan Ramachandran, Gordon L. Flynn, Norman D. Weiner
    Abstract:

    The hair follicle, hair shaft, and sebaceous gland collectively form what is recognized as the Pilosebaceous Unit. This complex, three-dimensional structure within the skin possesses a unique biochemistry, metabolism and immunology. Recent studies have focused on the hair follicle as a potential pathway for both localized and systemic drug delivery. Greater understanding of the structure and function of the hair follicle may facilitate rational design of drug formulations to target follicular delivery. Targeted drug delivery may enhance current therapeutic approaches to treating diseases of follicular origin. Presented here is a review of follicular drug delivery and a discussion of the feasibility of the Pilosebaceous Unit as a target site.

  • Follicular (Pilosebaceous Unit) deposition and pharmacological behavior of cimetidine as a function of formulation.
    Pharmaceutical Research, 1994
    Co-Authors: Linda M. Lieb, Gordon L. Flynn, Norman D. Weiner
    Abstract:

    The effect of formulation on cimetidine delivery to the Pilosebaceous Unit and other skin phases was studied. In vitro and in vivo deposition determinations as well as a pharmacodynamic antiandrogenic sebaceous gland bioassays were made. A complex variety of factors influence how the formulation affects both the degree of drug deposition and its pharmacological activity in the Pilosebaceous Unit. When cimetidine was applied in formulations at pH values where it was predominately unionized, the thermodynamic driving force proved the dominant factor in influencing the extent of drug deposition into the Pilosebaceous Unit. Although more cimetidine was deposited into the Pilosebaceous Unit in vivo from the phospho lipid-based liposomal formulation when cimetidine was ionized, this formulation was also the only one devoid of significant antiandro genic action. Of great importance, it is clear from the studies that deposition from complex formulations, such as liposomes, where bilayer/drug interactions can persist in the skin, may give a false impression of the activity of a drug within a tissue. Moreover, data for cimetidine in 50% alcohol solution show that one can maintain local effects while reducing systemic activity by simply manipulating drug concentration in the application.

Hideo Yagita - One of the best experts on this subject based on the ideXlab platform.

  • Receptor activator of NF-κB (RANK) stimulates the proliferation of epithelial cells of the epidermo-Pilosebaceous Unit
    Proceedings of the National Academy of Sciences of the United States of America, 2011
    Co-Authors: Vincent Duheron, Estelle Hess, Monique Duval, Marion Decossas, Beatriz Castaneda, Jennifer E. Klöpper, Leonela Amoasii, Jean-baptiste Barbaroux, Ifor R. Williams, Hideo Yagita
    Abstract:

    Receptor activator of NF-κB (RANK), known for controlling bone mass, has been recognized for its role in epithelial cell activation of the mammary gland. Because bone and the epidermo-Pilosebaceous Unit of the skin share a lifelong renewal activity where similar molecular players operate, and because mammary glands and hair follicles are both skin appendages, we have addressed the function of RANK in the hair follicle and the epidermis. Here, we show that mice deficient in RANK ligand (RANKL) are unable to initiate a new growth phase of the hair cycle and display arrested epidermal homeostasis. However, transgenic mice overexpressing RANK in the hair follicle or administration of recombinant RANKL both activate the hair cycle and epidermal growth. RANK is expressed by the hair follicle germ and bulge stem cells and the epidermal basal cells, cell types implicated in the renewal of the epidermo-Pilosebaceous Unit. RANK signaling is dispensable for the formation of the stem cell compartment and the inductive hair follicle mesenchyme, and the hair cycle can be rescued by Rankl knockout skin transplantation onto nude mice. RANKL is actively transcribed by the hair follicle at initiation of its growth phase, providing a mechanism for stem cell RANK engagement and hair-cycle entry. Thus, RANK–RANKL regulates hair renewal and epidermal homeostasis and provides a link between these two activities.

  • Receptor activator of NF-{kappa}B (RANK) stimulates the proliferation of epithelial cells of the epidermo-Pilosebaceous Unit.
    Proceedings of the National Academy of Sciences of the United States of America, 2011
    Co-Authors: Vincent Duheron, Estelle Hess, Monique Duval, Marion Decossas, Beatriz Castaneda, Jennifer E. Klöpper, Leonela Amoasii, Jean-baptiste Barbaroux, Ifor R. Williams, Hideo Yagita
    Abstract:

    Receptor activator of NF-κB (RANK), known for controlling bone mass, has been recognized for its role in epithelial cell activation of the mammary gland. Because bone and the epidermo-Pilosebaceous Unit of the skin share a lifelong renewal activity where similar molecular players operate, and because mammary glands and hair follicles are both skin appendages, we have addressed the function of RANK in the hair follicle and the epidermis. Here, we show that mice deficient in RANK ligand (RANKL) are unable to initiate a new growth phase of the hair cycle and display arrested epidermal homeostasis. However, transgenic mice overexpressing RANK in the hair follicle or administration of recombinant RANKL both activate the hair cycle and epidermal growth. RANK is expressed by the hair follicle germ and bulge stem cells and the epidermal basal cells, cell types implicated in the renewal of the epidermo-Pilosebaceous Unit. RANK signaling is dispensable for the formation of the stem cell compartment and the inductive hair follicle mesenchyme, and the hair cycle can be rescued by Rankl knockout skin transplantation onto nude mice. RANKL is actively transcribed by the hair follicle at initiation of its growth phase, providing a mechanism for stem cell RANK engagement and hair-cycle entry. Thus, RANK-RANKL regulates hair renewal and epidermal homeostasis and provides a link between these two activities.

Vincent Duheron - One of the best experts on this subject based on the ideXlab platform.

  • Receptor activator of NF-κB (RANK) stimulates the proliferation of epithelial cells of the epidermo-Pilosebaceous Unit
    Proceedings of the National Academy of Sciences of the United States of America, 2011
    Co-Authors: Vincent Duheron, Estelle Hess, Monique Duval, Marion Decossas, Beatriz Castaneda, Jennifer E. Klöpper, Leonela Amoasii, Jean-baptiste Barbaroux, Ifor R. Williams, Hideo Yagita
    Abstract:

    Receptor activator of NF-κB (RANK), known for controlling bone mass, has been recognized for its role in epithelial cell activation of the mammary gland. Because bone and the epidermo-Pilosebaceous Unit of the skin share a lifelong renewal activity where similar molecular players operate, and because mammary glands and hair follicles are both skin appendages, we have addressed the function of RANK in the hair follicle and the epidermis. Here, we show that mice deficient in RANK ligand (RANKL) are unable to initiate a new growth phase of the hair cycle and display arrested epidermal homeostasis. However, transgenic mice overexpressing RANK in the hair follicle or administration of recombinant RANKL both activate the hair cycle and epidermal growth. RANK is expressed by the hair follicle germ and bulge stem cells and the epidermal basal cells, cell types implicated in the renewal of the epidermo-Pilosebaceous Unit. RANK signaling is dispensable for the formation of the stem cell compartment and the inductive hair follicle mesenchyme, and the hair cycle can be rescued by Rankl knockout skin transplantation onto nude mice. RANKL is actively transcribed by the hair follicle at initiation of its growth phase, providing a mechanism for stem cell RANK engagement and hair-cycle entry. Thus, RANK–RANKL regulates hair renewal and epidermal homeostasis and provides a link between these two activities.

  • Receptor activator of NF-{kappa}B (RANK) stimulates the proliferation of epithelial cells of the epidermo-Pilosebaceous Unit.
    Proceedings of the National Academy of Sciences of the United States of America, 2011
    Co-Authors: Vincent Duheron, Estelle Hess, Monique Duval, Marion Decossas, Beatriz Castaneda, Jennifer E. Klöpper, Leonela Amoasii, Jean-baptiste Barbaroux, Ifor R. Williams, Hideo Yagita
    Abstract:

    Receptor activator of NF-κB (RANK), known for controlling bone mass, has been recognized for its role in epithelial cell activation of the mammary gland. Because bone and the epidermo-Pilosebaceous Unit of the skin share a lifelong renewal activity where similar molecular players operate, and because mammary glands and hair follicles are both skin appendages, we have addressed the function of RANK in the hair follicle and the epidermis. Here, we show that mice deficient in RANK ligand (RANKL) are unable to initiate a new growth phase of the hair cycle and display arrested epidermal homeostasis. However, transgenic mice overexpressing RANK in the hair follicle or administration of recombinant RANKL both activate the hair cycle and epidermal growth. RANK is expressed by the hair follicle germ and bulge stem cells and the epidermal basal cells, cell types implicated in the renewal of the epidermo-Pilosebaceous Unit. RANK signaling is dispensable for the formation of the stem cell compartment and the inductive hair follicle mesenchyme, and the hair cycle can be rescued by Rankl knockout skin transplantation onto nude mice. RANKL is actively transcribed by the hair follicle at initiation of its growth phase, providing a mechanism for stem cell RANK engagement and hair-cycle entry. Thus, RANK-RANKL regulates hair renewal and epidermal homeostasis and provides a link between these two activities.

Charlotte A Jonsson - One of the best experts on this subject based on the ideXlab platform.

  • the Pilosebaceous Unit a phthalate induced pathway to skin sensitization
    Toxicology and Applied Pharmacology, 2012
    Co-Authors: Carl Simonsson, Anna-lena Stenfeldt, Ann-therese Karlberg, Marica B. Ericson, Charlotte A Jonsson
    Abstract:

    Allergic contact dermatitis (ACD) is caused by low-molecular weight compounds called haptens. It has been shown that the potency of haptens can depend on the formulation in which they are applied on the skin. Specifically the sensitization potency of isothiocyanates, a group of haptens which can be released from e.g. adhesive tapes and neoprene materials, increases with the presence of phthalates; however, the underlying mechanisms are not clear. A better understanding of the mechanisms governing the potency of haptens is important, e.g. to improve the risk assessment and the formulation of chemicals in consumer products. In this study we have explored phthalate-induced effects on the sensitization potency, skin distribution, and reactivity of fluorescent model isothiocyanate haptens using non-invasive two-photon microscopy to provide new insights regarding vehicle effects in ACD. The data presented in this paper indicate that the sensitization potency of isothiocyanates increases when applied in combination with dibutylphthalate due to a specific uptake via the Pilosebaceous Units. The results highlight the importance of shunt pathways when evaluating the bioavailability of skin sensitizers. The findings also indicate that vehicle-dependent hapten reactivity towards stratum corneum proteins regulates the bioavailability, and thus the potency, of skin sensitizers.

  • The Pilosebaceous Unit—a phthalate-induced pathway to skin sensitization
    Toxicology and Applied Pharmacology, 2012
    Co-Authors: Carl Simonsson, Anna-lena Stenfeldt, Ann-therese Karlberg, Marica B. Ericson, Charlotte A Jonsson
    Abstract:

    Allergic contact dermatitis (ACD) is caused by low-molecular weight compounds called haptens. It has been shown that the potency of haptens can depend on the formulation in which they are applied on the skin. Specifically the sensitization potency of isothiocyanates, a group of haptens which can be released from e.g. adhesive tapes and neoprene materials, increases with the presence of phthalates; however, the underlying mechanisms are not clear. A better understanding of the mechanisms governing the potency of haptens is important, e.g. to improve the risk assessment and the formulation of chemicals in consumer products. In this study we have explored phthalate-induced effects on the sensitization potency, skin distribution, and reactivity of fluorescent model isothiocyanate haptens using non-invasive two-photon microscopy to provide new insights regarding vehicle effects in ACD. The data presented in this paper indicate that the sensitization potency of isothiocyanates increases when applied in combination with dibutylphthalate due to a specific uptake via the Pilosebaceous Units. The results highlight the importance of shunt pathways when evaluating the bioavailability of skin sensitizers. The findings also indicate that vehicle-dependent hapten reactivity towards stratum corneum proteins regulates the bioavailability, and thus the potency, of skin sensitizers.

Enrique Poblet - One of the best experts on this subject based on the ideXlab platform.